Blood Banking

Fresh frozen plasma

An “early and aggressive” approach to massive blood transfusion can save lives in military combat zones and may provide the same benefit in civilian trauma care as well, according to an article published in the AANA Journal.

The article describes 2 patients who required massive transfusions due to multiple gunshot wounds sustained while in combat zones.

One patient received an inadequate amount of blood products and ultimately died.

But the other patient benefitted from a protocol change to ensure an adequate amount of blood products was delivered quickly.

David Gaskin, CRNA, of Huntsville Memorial Hospital in Texas, and his colleagues described these cases in the journal.

The authors noted that, while providing care in a combat zone, the transfusion of packed red blood cells (PRBC) and fresh frozen plasma (FFP) is performed in a 1:1 ratio. However, the packaging and thawing techniques of the plasma can delay the delivery of blood products and prevent a patient from receiving enough blood.

Another issue in a military environment is the challenge of effectively communicating with live donors on site, which can cause delays in obtaining fresh blood supplies. Both of these issues can have life-threatening consequences for patients.

This is what happened with the first patient described in the article. The 38-year-old man sustained multiple gunshot wounds to the left side of the chest, left side of the back, and flank.

The surgical team was unable to maintain a high ratio of PRBCs to plasma and to infuse an adequate quantity of fresh whole blood (FWB) into this patient. He received 26 units of PRBCs, 5 units of FFP, 3 units of FWB, and 1 unit of cryoprecipitate.

The patient experienced trauma-induced coagulopathy, acidosis, and hypothermia. He died within 2 hours of presentation.

Because of this death, the team identified and implemented a protocol to keep 4 FFP units thawed and ready for immediate use at all times. They also identified and prescreened additional blood donors and implemented a phone roster and base-wide overhead system to enable rapid notification of these donors.

The second patient described in the article benefitted from these changes. This 23-year-old male sustained a gunshot wound to the left lower aspect of the abdomen and multiple gunshot wounds to bilateral lower extremities.

The “early and aggressive” use of FWB and plasma provided the necessary endogenous clotting factors and platelets to promote hemostasis in this patient. He received 18 units of PRBCs, 18 units of FFP, 2 units of cryoprecipitate, and 24 units of FWB.

Gaskin and his colleagues said these results suggest that efforts to incorporate a similar resuscitation strategy into civilian practice may improve outcomes, but it warrants continued study.

Fresh frozen plasma

An “early and aggressive” approach to massive blood transfusion can save lives in military combat zones and may provide the same benefit in civilian trauma care as well, according to an article published in the AANA Journal.

The article describes 2 patients who required massive transfusions due to multiple gunshot wounds sustained while in combat zones.

One patient received an inadequate amount of blood products and ultimately died.

But the other patient benefitted from a protocol change to ensure an adequate amount of blood products was delivered quickly.

David Gaskin, CRNA, of Huntsville Memorial Hospital in Texas, and his colleagues described these cases in the journal.

The authors noted that, while providing care in a combat zone, the transfusion of packed red blood cells (PRBC) and fresh frozen plasma (FFP) is performed in a 1:1 ratio. However, the packaging and thawing techniques of the plasma can delay the delivery of blood products and prevent a patient from receiving enough blood.

Another issue in a military environment is the challenge of effectively communicating with live donors on site, which can cause delays in obtaining fresh blood supplies. Both of these issues can have life-threatening consequences for patients.

This is what happened with the first patient described in the article. The 38-year-old man sustained multiple gunshot wounds to the left side of the chest, left side of the back, and flank.

The surgical team was unable to maintain a high ratio of PRBCs to plasma and to infuse an adequate quantity of fresh whole blood (FWB) into this patient. He received 26 units of PRBCs, 5 units of FFP, 3 units of FWB, and 1 unit of cryoprecipitate.

The patient experienced trauma-induced coagulopathy, acidosis, and hypothermia. He died within 2 hours of presentation.

Because of this death, the team identified and implemented a protocol to keep 4 FFP units thawed and ready for immediate use at all times. They also identified and prescreened additional blood donors and implemented a phone roster and base-wide overhead system to enable rapid notification of these donors.

The second patient described in the article benefitted from these changes. This 23-year-old male sustained a gunshot wound to the left lower aspect of the abdomen and multiple gunshot wounds to bilateral lower extremities.

The “early and aggressive” use of FWB and plasma provided the necessary endogenous clotting factors and platelets to promote hemostasis in this patient. He received 18 units of PRBCs, 18 units of FFP, 2 units of cryoprecipitate, and 24 units of FWB.

Gaskin and his colleagues said these results suggest that efforts to incorporate a similar resuscitation strategy into civilian practice may improve outcomes, but it warrants continued study.

Fresh frozen plasma

An “early and aggressive” approach to massive blood transfusion can save lives in military combat zones and may provide the same benefit in civilian trauma care as well, according to an article published in the AANA Journal.

The article describes 2 patients who required massive transfusions due to multiple gunshot wounds sustained while in combat zones.

One patient received an inadequate amount of blood products and ultimately died.

But the other patient benefitted from a protocol change to ensure an adequate amount of blood products was delivered quickly.

David Gaskin, CRNA, of Huntsville Memorial Hospital in Texas, and his colleagues described these cases in the journal.

The authors noted that, while providing care in a combat zone, the transfusion of packed red blood cells (PRBC) and fresh frozen plasma (FFP) is performed in a 1:1 ratio. However, the packaging and thawing techniques of the plasma can delay the delivery of blood products and prevent a patient from receiving enough blood.

Another issue in a military environment is the challenge of effectively communicating with live donors on site, which can cause delays in obtaining fresh blood supplies. Both of these issues can have life-threatening consequences for patients.

This is what happened with the first patient described in the article. The 38-year-old man sustained multiple gunshot wounds to the left side of the chest, left side of the back, and flank.

The surgical team was unable to maintain a high ratio of PRBCs to plasma and to infuse an adequate quantity of fresh whole blood (FWB) into this patient. He received 26 units of PRBCs, 5 units of FFP, 3 units of FWB, and 1 unit of cryoprecipitate.

The patient experienced trauma-induced coagulopathy, acidosis, and hypothermia. He died within 2 hours of presentation.

Because of this death, the team identified and implemented a protocol to keep 4 FFP units thawed and ready for immediate use at all times. They also identified and prescreened additional blood donors and implemented a phone roster and base-wide overhead system to enable rapid notification of these donors.

The second patient described in the article benefitted from these changes. This 23-year-old male sustained a gunshot wound to the left lower aspect of the abdomen and multiple gunshot wounds to bilateral lower extremities.

The “early and aggressive” use of FWB and plasma provided the necessary endogenous clotting factors and platelets to promote hemostasis in this patient. He received 18 units of PRBCs, 18 units of FFP, 2 units of cryoprecipitate, and 24 units of FWB.

Gaskin and his colleagues said these results suggest that efforts to incorporate a similar resuscitation strategy into civilian practice may improve outcomes, but it warrants continued study.

Blood sample collection

Photo by Juan D. Alfonso

ANAHEIM, CA—A new assay can detect and classify direct oral anticoagulants (DOACs) quickly and effectively, according to researchers.

In tests, the assay detected DOACs with greater than 90% sensitivity and specificity.

The assay classified the direct thrombin inhibitor (DTI) dabigatran correctly 100% of the time and classified factor Xa inhibitors (anti-Xa), which included rivaroxaban and apixaban, correctly 92% of the time.

The researchers believe this assay has the potential to be an effective tool for treating patients on DOACs who experience trauma or stroke, as well as those who require emergency/urgent surgery. And the ability to identify the type of anticoagulant a patient is taking can guide the reversal strategy.

Fowzia Zaman, PhD, of Haemonetics Corporation in Rosemont, Illinois, described the assay at the 2015 AABB Annual Meeting (abstract S60-030K). Haemonetics is the company developing the assay, and this research was supported by the company.

About the assay

“The current coagulation assays are not very sensitive to DOACs, especially in the therapeutic range,” Dr Zaman said. “Right now, there is no assay available that can classify the DOACs. This new assay can both detect and classify, and it will classify the DOACs either as a DTI or an anti-Xa.”

The assay is performed using Haemonetics’ TEG 6s system, a fully automated system for evaluating anticoagulation in a patient. It is based on viscoelasticity measurements using resonance frequency and disposable microfluidic cartridges. Each cartridge has 4 channels, and 2 of the channels are used for detection and classification.

Detection is performed using a factor Xa-based reagent, and classification utilizes an Ecarin-based reagent. All of the reagents are contained within the channel, so there is no reagent preparation required.

Each cartridge is loaded into the unit, and citrated whole blood is added, either with a transfer pipette or a syringe, to start the assay.

Reaction time (R-time) is used for detection and classification. R is defined as the time from the start of the sample run to the point of clot formation. It corresponds to an amplitude of 2 mm on the TEG tracing. It represents the initial enzymatic phase of clotting, and it is recorded in minutes.

Study population

The researchers tested the assay in 26 healthy subjects, 25 patients on DTI (all dabigatran), and 40 on anti-Xa therapy (24 on rivaroxaban, 16 on apixaban).

For healthy subjects, the mean age was 41±13, and 46% of subjects are male. Forty-six percent are Caucasian, 39% are African American, and 15% are Asian/“other”. The partial thromboplastin time (PTT) for these subjects was within the normal range, at 27.2±1.8 seconds.

In the DOAC population, the mean age was 68±12 for the anti-Xa group and 69±10 for the DTI group. Fifty percent and 72%, respectively, are male. And 50% and 64%, respectively, are Caucasian.

Most of the patients receiving DOACs were taking them for atrial fibrillation—88% in the anti-Xa group and 84% in the DTI group. Other underlying conditions were coronary artery disease—28% and 32%, respectively—and hypertension—60% and 64%, respectively.

Some patients were taking aspirin in addition to DOACs—30% in the anti-Xa group and 24% in the DTI group. And some were taking P2Y12 inhibitors—20% in the anti-Xa group and 24% in the DTI group.

The PTT was 30.4±4.6 seconds for the anti-Xa group and 36.6±7 seconds for the DTI group. Creatinine levels were 1.07±0.6 mg/dL and 1.05±0.2 mg/dL, respectively.

Assay results

The researchers analyzed citrated whole blood from the healthy volunteers to establish the baseline reference range. The cutoff for detection was 1.95 minutes, and the cutoff for classification was 1.9 minutes.

“What this means is that a person who does not have DOAC in their system should have an R-time of less than or equal to 1.95 minutes,” Dr Zaman explained.

The researchers also developed an algorithm for the detection and classification of DOACs. According to this algorithm, healthy subjects would have a short R-time in the detection channel and the classification channel.

Patients on anti-Xa would have a long R-time in the detection channel but a short R-time in the classification channel. And patients on a DTI would have a long R-time in both the detection channel and the classification channel.

The researchers found that, in the detection channel, on average, R-time was increased 66% for dabigatran, 125% for rivaroxaban, and 100% for apixaban, compared to the reference range. But the degree of elongation was dependent on the individual patient and the time from last DOAC dosage.

Using a cutoff of 2 minutes, the detection channel demonstrated 94% sensitivity and 96% specificity for all the DOACs combined.

“What this means is that, when a patient had a DOAC in their system, the assay was able to pick it up 94% of the time,” Dr Zaman explained.

In addition, the assay detected dabigatran correctly 100% of the time and anti-Xa therapy correctly 92% of the time.

“This TEG 6s DOAC assay is highly sensitive and specific for detecting and classifying DOACs,” Dr Zaman said in closing. “[T]he cutoffs for both the channels are close to 2 minutes, which means clinically relevant results are available within 5 minutes.”

“There is no reagent prep necessary, and it utilizes whole blood, so [there is] no spinning down to plasma. Therefore, it has the potential to be a point-of-care assay.”

Blood sample collection

Photo by Juan D. Alfonso

ANAHEIM, CA—A new assay can detect and classify direct oral anticoagulants (DOACs) quickly and effectively, according to researchers.

In tests, the assay detected DOACs with greater than 90% sensitivity and specificity.

The assay classified the direct thrombin inhibitor (DTI) dabigatran correctly 100% of the time and classified factor Xa inhibitors (anti-Xa), which included rivaroxaban and apixaban, correctly 92% of the time.

The researchers believe this assay has the potential to be an effective tool for treating patients on DOACs who experience trauma or stroke, as well as those who require emergency/urgent surgery. And the ability to identify the type of anticoagulant a patient is taking can guide the reversal strategy.

Fowzia Zaman, PhD, of Haemonetics Corporation in Rosemont, Illinois, described the assay at the 2015 AABB Annual Meeting (abstract S60-030K). Haemonetics is the company developing the assay, and this research was supported by the company.

About the assay

“The current coagulation assays are not very sensitive to DOACs, especially in the therapeutic range,” Dr Zaman said. “Right now, there is no assay available that can classify the DOACs. This new assay can both detect and classify, and it will classify the DOACs either as a DTI or an anti-Xa.”

The assay is performed using Haemonetics’ TEG 6s system, a fully automated system for evaluating anticoagulation in a patient. It is based on viscoelasticity measurements using resonance frequency and disposable microfluidic cartridges. Each cartridge has 4 channels, and 2 of the channels are used for detection and classification.

Detection is performed using a factor Xa-based reagent, and classification utilizes an Ecarin-based reagent. All of the reagents are contained within the channel, so there is no reagent preparation required.

Each cartridge is loaded into the unit, and citrated whole blood is added, either with a transfer pipette or a syringe, to start the assay.

Reaction time (R-time) is used for detection and classification. R is defined as the time from the start of the sample run to the point of clot formation. It corresponds to an amplitude of 2 mm on the TEG tracing. It represents the initial enzymatic phase of clotting, and it is recorded in minutes.

Study population

The researchers tested the assay in 26 healthy subjects, 25 patients on DTI (all dabigatran), and 40 on anti-Xa therapy (24 on rivaroxaban, 16 on apixaban).

For healthy subjects, the mean age was 41±13, and 46% of subjects are male. Forty-six percent are Caucasian, 39% are African American, and 15% are Asian/“other”. The partial thromboplastin time (PTT) for these subjects was within the normal range, at 27.2±1.8 seconds.

In the DOAC population, the mean age was 68±12 for the anti-Xa group and 69±10 for the DTI group. Fifty percent and 72%, respectively, are male. And 50% and 64%, respectively, are Caucasian.

Most of the patients receiving DOACs were taking them for atrial fibrillation—88% in the anti-Xa group and 84% in the DTI group. Other underlying conditions were coronary artery disease—28% and 32%, respectively—and hypertension—60% and 64%, respectively.

Some patients were taking aspirin in addition to DOACs—30% in the anti-Xa group and 24% in the DTI group. And some were taking P2Y12 inhibitors—20% in the anti-Xa group and 24% in the DTI group.

The PTT was 30.4±4.6 seconds for the anti-Xa group and 36.6±7 seconds for the DTI group. Creatinine levels were 1.07±0.6 mg/dL and 1.05±0.2 mg/dL, respectively.

Assay results

The researchers analyzed citrated whole blood from the healthy volunteers to establish the baseline reference range. The cutoff for detection was 1.95 minutes, and the cutoff for classification was 1.9 minutes.

“What this means is that a person who does not have DOAC in their system should have an R-time of less than or equal to 1.95 minutes,” Dr Zaman explained.

The researchers also developed an algorithm for the detection and classification of DOACs. According to this algorithm, healthy subjects would have a short R-time in the detection channel and the classification channel.

Patients on anti-Xa would have a long R-time in the detection channel but a short R-time in the classification channel. And patients on a DTI would have a long R-time in both the detection channel and the classification channel.

The researchers found that, in the detection channel, on average, R-time was increased 66% for dabigatran, 125% for rivaroxaban, and 100% for apixaban, compared to the reference range. But the degree of elongation was dependent on the individual patient and the time from last DOAC dosage.

Using a cutoff of 2 minutes, the detection channel demonstrated 94% sensitivity and 96% specificity for all the DOACs combined.

“What this means is that, when a patient had a DOAC in their system, the assay was able to pick it up 94% of the time,” Dr Zaman explained.

In addition, the assay detected dabigatran correctly 100% of the time and anti-Xa therapy correctly 92% of the time.

“This TEG 6s DOAC assay is highly sensitive and specific for detecting and classifying DOACs,” Dr Zaman said in closing. “[T]he cutoffs for both the channels are close to 2 minutes, which means clinically relevant results are available within 5 minutes.”

“There is no reagent prep necessary, and it utilizes whole blood, so [there is] no spinning down to plasma. Therefore, it has the potential to be a point-of-care assay.”

Blood sample collection

Photo by Juan D. Alfonso

ANAHEIM, CA—A new assay can detect and classify direct oral anticoagulants (DOACs) quickly and effectively, according to researchers.

In tests, the assay detected DOACs with greater than 90% sensitivity and specificity.

The assay classified the direct thrombin inhibitor (DTI) dabigatran correctly 100% of the time and classified factor Xa inhibitors (anti-Xa), which included rivaroxaban and apixaban, correctly 92% of the time.

The researchers believe this assay has the potential to be an effective tool for treating patients on DOACs who experience trauma or stroke, as well as those who require emergency/urgent surgery. And the ability to identify the type of anticoagulant a patient is taking can guide the reversal strategy.

Fowzia Zaman, PhD, of Haemonetics Corporation in Rosemont, Illinois, described the assay at the 2015 AABB Annual Meeting (abstract S60-030K). Haemonetics is the company developing the assay, and this research was supported by the company.

About the assay

“The current coagulation assays are not very sensitive to DOACs, especially in the therapeutic range,” Dr Zaman said. “Right now, there is no assay available that can classify the DOACs. This new assay can both detect and classify, and it will classify the DOACs either as a DTI or an anti-Xa.”

The assay is performed using Haemonetics’ TEG 6s system, a fully automated system for evaluating anticoagulation in a patient. It is based on viscoelasticity measurements using resonance frequency and disposable microfluidic cartridges. Each cartridge has 4 channels, and 2 of the channels are used for detection and classification.

Detection is performed using a factor Xa-based reagent, and classification utilizes an Ecarin-based reagent. All of the reagents are contained within the channel, so there is no reagent preparation required.

Each cartridge is loaded into the unit, and citrated whole blood is added, either with a transfer pipette or a syringe, to start the assay.

Reaction time (R-time) is used for detection and classification. R is defined as the time from the start of the sample run to the point of clot formation. It corresponds to an amplitude of 2 mm on the TEG tracing. It represents the initial enzymatic phase of clotting, and it is recorded in minutes.

Study population

The researchers tested the assay in 26 healthy subjects, 25 patients on DTI (all dabigatran), and 40 on anti-Xa therapy (24 on rivaroxaban, 16 on apixaban).

For healthy subjects, the mean age was 41±13, and 46% of subjects are male. Forty-six percent are Caucasian, 39% are African American, and 15% are Asian/“other”. The partial thromboplastin time (PTT) for these subjects was within the normal range, at 27.2±1.8 seconds.

In the DOAC population, the mean age was 68±12 for the anti-Xa group and 69±10 for the DTI group. Fifty percent and 72%, respectively, are male. And 50% and 64%, respectively, are Caucasian.

Most of the patients receiving DOACs were taking them for atrial fibrillation—88% in the anti-Xa group and 84% in the DTI group. Other underlying conditions were coronary artery disease—28% and 32%, respectively—and hypertension—60% and 64%, respectively.

Some patients were taking aspirin in addition to DOACs—30% in the anti-Xa group and 24% in the DTI group. And some were taking P2Y12 inhibitors—20% in the anti-Xa group and 24% in the DTI group.

The PTT was 30.4±4.6 seconds for the anti-Xa group and 36.6±7 seconds for the DTI group. Creatinine levels were 1.07±0.6 mg/dL and 1.05±0.2 mg/dL, respectively.

Assay results

The researchers analyzed citrated whole blood from the healthy volunteers to establish the baseline reference range. The cutoff for detection was 1.95 minutes, and the cutoff for classification was 1.9 minutes.

“What this means is that a person who does not have DOAC in their system should have an R-time of less than or equal to 1.95 minutes,” Dr Zaman explained.

The researchers also developed an algorithm for the detection and classification of DOACs. According to this algorithm, healthy subjects would have a short R-time in the detection channel and the classification channel.

Patients on anti-Xa would have a long R-time in the detection channel but a short R-time in the classification channel. And patients on a DTI would have a long R-time in both the detection channel and the classification channel.

The researchers found that, in the detection channel, on average, R-time was increased 66% for dabigatran, 125% for rivaroxaban, and 100% for apixaban, compared to the reference range. But the degree of elongation was dependent on the individual patient and the time from last DOAC dosage.

Using a cutoff of 2 minutes, the detection channel demonstrated 94% sensitivity and 96% specificity for all the DOACs combined.

“What this means is that, when a patient had a DOAC in their system, the assay was able to pick it up 94% of the time,” Dr Zaman explained.

In addition, the assay detected dabigatran correctly 100% of the time and anti-Xa therapy correctly 92% of the time.

“This TEG 6s DOAC assay is highly sensitive and specific for detecting and classifying DOACs,” Dr Zaman said in closing. “[T]he cutoffs for both the channels are close to 2 minutes, which means clinically relevant results are available within 5 minutes.”

“There is no reagent prep necessary, and it utilizes whole blood, so [there is] no spinning down to plasma. Therefore, it has the potential to be a point-of-care assay.”

Red blood cells

ANAHEIM, CA—Interim results of a large study suggest a blood donor’s genetic background and frequency of donation influence

red blood cell (RBC) storage and stress hemolysis.

Investigators found that donor ethnicity and gender both affected hemolysis, but the effects sometimes differed between storage and stress hemolysis.

Similarly, RBCs from frequent donors were more susceptible to storage and osmotic hemolysis but less susceptible to oxidative hemolysis.

Tamir Kanias, PhD, of the University of Pittsburgh in Pennsylvania, presented these findings at the 2015 AABB Annual Meeting (abstract S73-040A).

“We now know that some donor red cells store very well, and, even after 42 days of storage, there is hardly any hemolysis,” Dr Kanias noted. “[But for] some donors, their red cells are starting to degrade maybe 5 or 6 days after collection.”

With that in mind, Dr Kanias and his colleagues set out to define the genetic and metabolic basis for donor-specific differences in hemolysis in stored RBCs.

They analyzed RBCs collected at 4 centers as part of the REDS-III study. The team took 15 mL of RBCs from fresh units donated for transfusion and stored the cells in transfer bags to measure hemolysis. The transfer bags are miniature versions of the bags used to store RBCs for transfusion.

Dr Kanias presented interim findings in samples from more than 8000 donors. He and his colleagues looked at donor ethnicity, gender, and age. The team also assessed whether subjects were “high-intensity” donors, which was defined as donating RBCs 10 or more times in the previous 24 months without a low-hemoglobin deferral.

The donors’ samples were stored for 39 to 42 days before the investigators assessed hemolysis. They measured end-of-storage hemolysis in unwashed red cells, then washed the RBCs and assessed osmotic hemolysis (Pink test) and oxidative hemolysis (AAPH).

Ethnicity and intensity

Tests showed that RBCs from African American and high-intensity donors (more than 90% of whom were Caucasian) were more susceptible to storage hemolysis than RBCs from the other donor groups analyzed.

RBCs from Caucasian donors and high-intensity donors were susceptible to osmotic hemolysis, while RBCs from African American and Asian donors were more resistant.

“We hypothesize that this [resistance] may be related to some of these donors carrying traits for sickle cell disease or thalassemia,” Dr Kanias said. “Both diseases are known to render red cells more resistant to osmotic hemolysis, but of course, it could be [explained by] new mutations that we don’t know of.”

RBCs from Hispanic donors and African American donors were more susceptible to oxidative hemolysis, but the opposite was true of RBCs from high-intensity donors.

“What was really interesting is that the high-intensity donors that had higher end-of-storage hemolysis and higher susceptibility to osmotic hemolysis actually became more resistant to oxidative hemolysis,” Dr Kanias said.

“It is possible that the lower levels of iron in the red cells of these donors actually protects from oxidative hemolysis. Iron is redox-active, and a lot of the AAPH-induced hemolysis is mediated by iron interactions.”

Group comparisons

Looking at the data another way, the investigators compared samples from Caucasians to samples from the other ethnic groups and the high-intensity donors.

RBCs from African American donors had significantly higher storage hemolysis (P=0.0078), lower osmotic hemolysis (P<0.0001), and higher oxidative hemolysis (P=0.0008) than RBCs from Caucasians.

RBCs from Asians had significantly lower osmotic hemolysis (P<0.0001) than Caucasian RBCs, but there was no significant difference in storage hemolysis (P=0.69) or oxidative hemolysis (P=0.41) between the 2 groups.

RBCs from Hispanic donors were significantly more susceptible to oxidative hemolysis (P<0.0001) than Caucasian RBCs, but there was no significant difference between the groups with regard to storage hemolysis (P=0.89) or osmotic hemolysis (P=0.10).

RBCs from high-intensity donors had significantly higher storage hemolysis (P<0.0001) and lower oxidative hemolysis (P<0.0001) than Caucasian RBCs. There was no significant difference in osmotic hemolysis (P=0.84)

Gender and age

As in other studies, Dr Kanias and his colleagues found that RBCs from females hemolyzed significantly less than RBCs from males. This was true for storage hemolysis, osmotic hemolysis, and oxidative hemolysis (P<0.0001 for all).

“Just to note, the gender effect was more dramatic in storage and osmotic rather than oxidative, which suggests that the gender effect is more on the membrane or membrane integrity rather than antioxidant capacity,” Dr Kanias said.

He and his colleagues then looked at donor age and observed the gender effect at every age analyzed (18 to 65+). He noted that hemolysis fluctuated throughout the age groups, so the investigators couldn’t draw any concrete conclusions about hemolysis and donor age.

“One interesting thing to note is that, in all the assays, in young males—like around 20—there’s an increase in hemolysis where there’s a decrease in females,” Dr Kanias said. “This may be related to the effect of sex hormones.”

Genetic modifiers

The investigators also assessed how the 3 hemolytic assays relate to each other and found very weak correlations between them. Pearson correlations were 0.12 between storage and osmotic hemolysis, 0.0041 between storage and oxidative hemolysis, and 0.058 between osmotic and oxidative hemolysis.

“This is kind of cool because it may mean that there is a different genetic modifier affecting each of these phenomena,” Dr Kanias said.

He and his colleagues are now working to identify genetic and metabolic modifiers of hemolysis.

Red blood cells

ANAHEIM, CA—Interim results of a large study suggest a blood donor’s genetic background and frequency of donation influence

red blood cell (RBC) storage and stress hemolysis.

Investigators found that donor ethnicity and gender both affected hemolysis, but the effects sometimes differed between storage and stress hemolysis.

Similarly, RBCs from frequent donors were more susceptible to storage and osmotic hemolysis but less susceptible to oxidative hemolysis.

Tamir Kanias, PhD, of the University of Pittsburgh in Pennsylvania, presented these findings at the 2015 AABB Annual Meeting (abstract S73-040A).

“We now know that some donor red cells store very well, and, even after 42 days of storage, there is hardly any hemolysis,” Dr Kanias noted. “[But for] some donors, their red cells are starting to degrade maybe 5 or 6 days after collection.”

With that in mind, Dr Kanias and his colleagues set out to define the genetic and metabolic basis for donor-specific differences in hemolysis in stored RBCs.

They analyzed RBCs collected at 4 centers as part of the REDS-III study. The team took 15 mL of RBCs from fresh units donated for transfusion and stored the cells in transfer bags to measure hemolysis. The transfer bags are miniature versions of the bags used to store RBCs for transfusion.

Dr Kanias presented interim findings in samples from more than 8000 donors. He and his colleagues looked at donor ethnicity, gender, and age. The team also assessed whether subjects were “high-intensity” donors, which was defined as donating RBCs 10 or more times in the previous 24 months without a low-hemoglobin deferral.

The donors’ samples were stored for 39 to 42 days before the investigators assessed hemolysis. They measured end-of-storage hemolysis in unwashed red cells, then washed the RBCs and assessed osmotic hemolysis (Pink test) and oxidative hemolysis (AAPH).

Ethnicity and intensity

Tests showed that RBCs from African American and high-intensity donors (more than 90% of whom were Caucasian) were more susceptible to storage hemolysis than RBCs from the other donor groups analyzed.

RBCs from Caucasian donors and high-intensity donors were susceptible to osmotic hemolysis, while RBCs from African American and Asian donors were more resistant.

“We hypothesize that this [resistance] may be related to some of these donors carrying traits for sickle cell disease or thalassemia,” Dr Kanias said. “Both diseases are known to render red cells more resistant to osmotic hemolysis, but of course, it could be [explained by] new mutations that we don’t know of.”

RBCs from Hispanic donors and African American donors were more susceptible to oxidative hemolysis, but the opposite was true of RBCs from high-intensity donors.

“What was really interesting is that the high-intensity donors that had higher end-of-storage hemolysis and higher susceptibility to osmotic hemolysis actually became more resistant to oxidative hemolysis,” Dr Kanias said.

“It is possible that the lower levels of iron in the red cells of these donors actually protects from oxidative hemolysis. Iron is redox-active, and a lot of the AAPH-induced hemolysis is mediated by iron interactions.”

Group comparisons

Looking at the data another way, the investigators compared samples from Caucasians to samples from the other ethnic groups and the high-intensity donors.

RBCs from African American donors had significantly higher storage hemolysis (P=0.0078), lower osmotic hemolysis (P<0.0001), and higher oxidative hemolysis (P=0.0008) than RBCs from Caucasians.

RBCs from Asians had significantly lower osmotic hemolysis (P<0.0001) than Caucasian RBCs, but there was no significant difference in storage hemolysis (P=0.69) or oxidative hemolysis (P=0.41) between the 2 groups.

RBCs from Hispanic donors were significantly more susceptible to oxidative hemolysis (P<0.0001) than Caucasian RBCs, but there was no significant difference between the groups with regard to storage hemolysis (P=0.89) or osmotic hemolysis (P=0.10).

RBCs from high-intensity donors had significantly higher storage hemolysis (P<0.0001) and lower oxidative hemolysis (P<0.0001) than Caucasian RBCs. There was no significant difference in osmotic hemolysis (P=0.84)

Gender and age

As in other studies, Dr Kanias and his colleagues found that RBCs from females hemolyzed significantly less than RBCs from males. This was true for storage hemolysis, osmotic hemolysis, and oxidative hemolysis (P<0.0001 for all).

“Just to note, the gender effect was more dramatic in storage and osmotic rather than oxidative, which suggests that the gender effect is more on the membrane or membrane integrity rather than antioxidant capacity,” Dr Kanias said.

He and his colleagues then looked at donor age and observed the gender effect at every age analyzed (18 to 65+). He noted that hemolysis fluctuated throughout the age groups, so the investigators couldn’t draw any concrete conclusions about hemolysis and donor age.

“One interesting thing to note is that, in all the assays, in young males—like around 20—there’s an increase in hemolysis where there’s a decrease in females,” Dr Kanias said. “This may be related to the effect of sex hormones.”

Genetic modifiers

The investigators also assessed how the 3 hemolytic assays relate to each other and found very weak correlations between them. Pearson correlations were 0.12 between storage and osmotic hemolysis, 0.0041 between storage and oxidative hemolysis, and 0.058 between osmotic and oxidative hemolysis.

“This is kind of cool because it may mean that there is a different genetic modifier affecting each of these phenomena,” Dr Kanias said.

He and his colleagues are now working to identify genetic and metabolic modifiers of hemolysis.

Red blood cells

ANAHEIM, CA—Interim results of a large study suggest a blood donor’s genetic background and frequency of donation influence

red blood cell (RBC) storage and stress hemolysis.

Investigators found that donor ethnicity and gender both affected hemolysis, but the effects sometimes differed between storage and stress hemolysis.

Similarly, RBCs from frequent donors were more susceptible to storage and osmotic hemolysis but less susceptible to oxidative hemolysis.

Tamir Kanias, PhD, of the University of Pittsburgh in Pennsylvania, presented these findings at the 2015 AABB Annual Meeting (abstract S73-040A).

“We now know that some donor red cells store very well, and, even after 42 days of storage, there is hardly any hemolysis,” Dr Kanias noted. “[But for] some donors, their red cells are starting to degrade maybe 5 or 6 days after collection.”

With that in mind, Dr Kanias and his colleagues set out to define the genetic and metabolic basis for donor-specific differences in hemolysis in stored RBCs.

They analyzed RBCs collected at 4 centers as part of the REDS-III study. The team took 15 mL of RBCs from fresh units donated for transfusion and stored the cells in transfer bags to measure hemolysis. The transfer bags are miniature versions of the bags used to store RBCs for transfusion.

Dr Kanias presented interim findings in samples from more than 8000 donors. He and his colleagues looked at donor ethnicity, gender, and age. The team also assessed whether subjects were “high-intensity” donors, which was defined as donating RBCs 10 or more times in the previous 24 months without a low-hemoglobin deferral.

The donors’ samples were stored for 39 to 42 days before the investigators assessed hemolysis. They measured end-of-storage hemolysis in unwashed red cells, then washed the RBCs and assessed osmotic hemolysis (Pink test) and oxidative hemolysis (AAPH).

Ethnicity and intensity

Tests showed that RBCs from African American and high-intensity donors (more than 90% of whom were Caucasian) were more susceptible to storage hemolysis than RBCs from the other donor groups analyzed.

RBCs from Caucasian donors and high-intensity donors were susceptible to osmotic hemolysis, while RBCs from African American and Asian donors were more resistant.

“We hypothesize that this [resistance] may be related to some of these donors carrying traits for sickle cell disease or thalassemia,” Dr Kanias said. “Both diseases are known to render red cells more resistant to osmotic hemolysis, but of course, it could be [explained by] new mutations that we don’t know of.”

RBCs from Hispanic donors and African American donors were more susceptible to oxidative hemolysis, but the opposite was true of RBCs from high-intensity donors.

“What was really interesting is that the high-intensity donors that had higher end-of-storage hemolysis and higher susceptibility to osmotic hemolysis actually became more resistant to oxidative hemolysis,” Dr Kanias said.

“It is possible that the lower levels of iron in the red cells of these donors actually protects from oxidative hemolysis. Iron is redox-active, and a lot of the AAPH-induced hemolysis is mediated by iron interactions.”

Group comparisons

Looking at the data another way, the investigators compared samples from Caucasians to samples from the other ethnic groups and the high-intensity donors.

RBCs from African American donors had significantly higher storage hemolysis (P=0.0078), lower osmotic hemolysis (P<0.0001), and higher oxidative hemolysis (P=0.0008) than RBCs from Caucasians.

RBCs from Asians had significantly lower osmotic hemolysis (P<0.0001) than Caucasian RBCs, but there was no significant difference in storage hemolysis (P=0.69) or oxidative hemolysis (P=0.41) between the 2 groups.

RBCs from Hispanic donors were significantly more susceptible to oxidative hemolysis (P<0.0001) than Caucasian RBCs, but there was no significant difference between the groups with regard to storage hemolysis (P=0.89) or osmotic hemolysis (P=0.10).

RBCs from high-intensity donors had significantly higher storage hemolysis (P<0.0001) and lower oxidative hemolysis (P<0.0001) than Caucasian RBCs. There was no significant difference in osmotic hemolysis (P=0.84)

Gender and age

As in other studies, Dr Kanias and his colleagues found that RBCs from females hemolyzed significantly less than RBCs from males. This was true for storage hemolysis, osmotic hemolysis, and oxidative hemolysis (P<0.0001 for all).

“Just to note, the gender effect was more dramatic in storage and osmotic rather than oxidative, which suggests that the gender effect is more on the membrane or membrane integrity rather than antioxidant capacity,” Dr Kanias said.

He and his colleagues then looked at donor age and observed the gender effect at every age analyzed (18 to 65+). He noted that hemolysis fluctuated throughout the age groups, so the investigators couldn’t draw any concrete conclusions about hemolysis and donor age.

“One interesting thing to note is that, in all the assays, in young males—like around 20—there’s an increase in hemolysis where there’s a decrease in females,” Dr Kanias said. “This may be related to the effect of sex hormones.”

Genetic modifiers

The investigators also assessed how the 3 hemolytic assays relate to each other and found very weak correlations between them. Pearson correlations were 0.12 between storage and osmotic hemolysis, 0.0041 between storage and oxidative hemolysis, and 0.058 between osmotic and oxidative hemolysis.

“This is kind of cool because it may mean that there is a different genetic modifier affecting each of these phenomena,” Dr Kanias said.

He and his colleagues are now working to identify genetic and metabolic modifiers of hemolysis.

Blood donation

Photo by Charles Haymond

ANAHEIM, CA—Lifting the lifetime ban on blood donations from men who have sex with men (MSM) has not altered the safety of the blood supply in Canada, according to a new study.

The study showed no increase in the rate of HIV-positive blood donations since Canada changed its policy regarding MSM blood donors, allowing MSM to donate if they have not had sexual contact with another man in the last 5 years.

Because of this finding, Canada may shorten the deferral period for MSM blood donors to 1 year, according to Sheila F. O’Brien, PhD, of Canadian Blood Services in Ottawa, Ontario, Canada.

Dr O’Brien mentioned this possibility and presented data from the study at the 2015 AABB Annual Meeting (abstract S35-030E*).

Prior to 2013, MSM in Canada were not allowed to donate blood if they had any sexual contact with another male since 1977. Females were barred from donating if, in the last year, they had sexual contact with a man who had sex with another man after 1977.

On July 22, 2013, Canada changed this policy so that MSM can donate blood if they have abstained from sexual contact with another man for the past 5 years. The deferral period for females is still 12 months if they have had sex with a man who has had sex with another man in the last 5 years, but there is no deferral if the man had sex with another man more than 5 years before.

To evaluate the impact of this policy change, Dr O’Brien and her colleagues assessed compliance with the MSM criteria before and after the change, as well as the number of HIV-positive blood donations before and after the change.

The researchers also assessed the number of donors who would have been deferred according to the old MSM criteria but donated blood under the new criteria.

MSM history

The researchers selected random male donors of whole blood each month from October 2012 to February 2013 (pre-change) and from October 2014 to February 2015 (post-change). These donors were invited to complete an anonymous online survey about their MSM history.

The survey was completed by 9669 donors before the policy change and 6881 donors after the change. There were 77 donors with MSM history before the change (20% first-time donors, 80% repeat) and 75 donors with MSM history after the change (22% first-time, 78% repeat).

Compliance with policy

After the change in policy for MSM blood donors, there was no significant change in the proportion of donors who had recent MSM history but donated anyway (non-compliant). Before the change, 0.37% of blood donors had an MSM partner in the last 5 years, compared to 0.43% after the change (P=0.54).

However, there was a significant change in the proportion of blood donors with MSM history further in the past. Before the MSM policy change, 0.42% of donors had an MSM partner but not in the last 5 years, compared to 0.66% of donors after the change (P=0.04).

“So we have an improvement in compliance, but it’s mainly because the donors are no longer deferrable,” Dr O’Brien explained.

“Donating while ineligible because of MSM history is actually quite rare, and the percentage of donors with MSM history in the last 5 years did not change when we changed the criteria. But we did see a modest increase in newly eligible MSM, so those that had more than 5 years since their last male-to-male sex.”

In all, there were 112 donors who were newly eligible due to the policy change and did, in fact, donate blood between July 22, 2013 and July 21, 2015. Five of these donors were females who had sexual contact with MSMs.

There were 70 “reinstated” donors in the first year after the policy change and 42 in the second year.

HIV-positive donations

The researchers monitored HIV rates in all blood donations from January 2010 to March 2015.

The rates of HIV-positive donations were as follows: 0.20 for 2010 (2/989,916), 0.50 for 2011 (5/995,122), 0.51 for 2012 (5/987,527), 0 (0/525,337) from January 1, 2013 to July 21, 2013 (before the policy change), 0.54 from July 22, 2013 to July 21, 2014 (5/929,656), and 0.22 from July 22, 2014 to July 21, 2015 (2/893,513).

“So absolutely no change in HIV rate following implementation of our 5-year deferral,” Dr O’Brien said.

In all, there were 7 HIV-positive donations after the policy change. Four were from male donors, and 3 were from females.

Three of the male donors (2 first-time donors, 1 repeat) denied having MSM risk factors, and 1 first-time male donor was aware he was HIV-positive at the time of donation. This man said he donated to determine if his HIV medication was working.

Two of the females were repeat donors, and 1 was a first-timer. The first-time donor did not acknowledge any MSM risk factors. One of the repeat donors had a sexual relationship with a bisexual male who was HIV-positive. The other repeat donor had multiple sexual partners, 1 of whom was known to be hepatitis C-positive.

Future policy change

Dr O’Brien noted that the LGBTQ community in Canada has advocated abolishing the deferral period for MSM blood donors or changing to a risk-based policy that would allow more individuals with MSM history to donate blood.

She said the combined blood services in Canada—Canadian Blood Services and Héma-Québec—are now considering a 12-month deferral period for individuals with MSM history.

“We’re pretty sure we’re going to go ahead,” she noted.

However, the groups must submit a policy request to Health Canada, which will ultimately make the decision.

*Data in the abstract differ from data presented at the meeting.

Blood donation

Photo by Charles Haymond

ANAHEIM, CA—Lifting the lifetime ban on blood donations from men who have sex with men (MSM) has not altered the safety of the blood supply in Canada, according to a new study.

The study showed no increase in the rate of HIV-positive blood donations since Canada changed its policy regarding MSM blood donors, allowing MSM to donate if they have not had sexual contact with another man in the last 5 years.

Because of this finding, Canada may shorten the deferral period for MSM blood donors to 1 year, according to Sheila F. O’Brien, PhD, of Canadian Blood Services in Ottawa, Ontario, Canada.

Dr O’Brien mentioned this possibility and presented data from the study at the 2015 AABB Annual Meeting (abstract S35-030E*).

Prior to 2013, MSM in Canada were not allowed to donate blood if they had any sexual contact with another male since 1977. Females were barred from donating if, in the last year, they had sexual contact with a man who had sex with another man after 1977.

On July 22, 2013, Canada changed this policy so that MSM can donate blood if they have abstained from sexual contact with another man for the past 5 years. The deferral period for females is still 12 months if they have had sex with a man who has had sex with another man in the last 5 years, but there is no deferral if the man had sex with another man more than 5 years before.

To evaluate the impact of this policy change, Dr O’Brien and her colleagues assessed compliance with the MSM criteria before and after the change, as well as the number of HIV-positive blood donations before and after the change.

The researchers also assessed the number of donors who would have been deferred according to the old MSM criteria but donated blood under the new criteria.

MSM history

The researchers selected random male donors of whole blood each month from October 2012 to February 2013 (pre-change) and from October 2014 to February 2015 (post-change). These donors were invited to complete an anonymous online survey about their MSM history.

The survey was completed by 9669 donors before the policy change and 6881 donors after the change. There were 77 donors with MSM history before the change (20% first-time donors, 80% repeat) and 75 donors with MSM history after the change (22% first-time, 78% repeat).

Compliance with policy

After the change in policy for MSM blood donors, there was no significant change in the proportion of donors who had recent MSM history but donated anyway (non-compliant). Before the change, 0.37% of blood donors had an MSM partner in the last 5 years, compared to 0.43% after the change (P=0.54).

However, there was a significant change in the proportion of blood donors with MSM history further in the past. Before the MSM policy change, 0.42% of donors had an MSM partner but not in the last 5 years, compared to 0.66% of donors after the change (P=0.04).

“So we have an improvement in compliance, but it’s mainly because the donors are no longer deferrable,” Dr O’Brien explained.

“Donating while ineligible because of MSM history is actually quite rare, and the percentage of donors with MSM history in the last 5 years did not change when we changed the criteria. But we did see a modest increase in newly eligible MSM, so those that had more than 5 years since their last male-to-male sex.”

In all, there were 112 donors who were newly eligible due to the policy change and did, in fact, donate blood between July 22, 2013 and July 21, 2015. Five of these donors were females who had sexual contact with MSMs.

There were 70 “reinstated” donors in the first year after the policy change and 42 in the second year.

HIV-positive donations

The researchers monitored HIV rates in all blood donations from January 2010 to March 2015.

The rates of HIV-positive donations were as follows: 0.20 for 2010 (2/989,916), 0.50 for 2011 (5/995,122), 0.51 for 2012 (5/987,527), 0 (0/525,337) from January 1, 2013 to July 21, 2013 (before the policy change), 0.54 from July 22, 2013 to July 21, 2014 (5/929,656), and 0.22 from July 22, 2014 to July 21, 2015 (2/893,513).

“So absolutely no change in HIV rate following implementation of our 5-year deferral,” Dr O’Brien said.

In all, there were 7 HIV-positive donations after the policy change. Four were from male donors, and 3 were from females.

Three of the male donors (2 first-time donors, 1 repeat) denied having MSM risk factors, and 1 first-time male donor was aware he was HIV-positive at the time of donation. This man said he donated to determine if his HIV medication was working.

Two of the females were repeat donors, and 1 was a first-timer. The first-time donor did not acknowledge any MSM risk factors. One of the repeat donors had a sexual relationship with a bisexual male who was HIV-positive. The other repeat donor had multiple sexual partners, 1 of whom was known to be hepatitis C-positive.

Future policy change

Dr O’Brien noted that the LGBTQ community in Canada has advocated abolishing the deferral period for MSM blood donors or changing to a risk-based policy that would allow more individuals with MSM history to donate blood.

She said the combined blood services in Canada—Canadian Blood Services and Héma-Québec—are now considering a 12-month deferral period for individuals with MSM history.

“We’re pretty sure we’re going to go ahead,” she noted.

However, the groups must submit a policy request to Health Canada, which will ultimately make the decision.

*Data in the abstract differ from data presented at the meeting.

Blood donation

Photo by Charles Haymond

ANAHEIM, CA—Lifting the lifetime ban on blood donations from men who have sex with men (MSM) has not altered the safety of the blood supply in Canada, according to a new study.

The study showed no increase in the rate of HIV-positive blood donations since Canada changed its policy regarding MSM blood donors, allowing MSM to donate if they have not had sexual contact with another man in the last 5 years.

Because of this finding, Canada may shorten the deferral period for MSM blood donors to 1 year, according to Sheila F. O’Brien, PhD, of Canadian Blood Services in Ottawa, Ontario, Canada.

Dr O’Brien mentioned this possibility and presented data from the study at the 2015 AABB Annual Meeting (abstract S35-030E*).

Prior to 2013, MSM in Canada were not allowed to donate blood if they had any sexual contact with another male since 1977. Females were barred from donating if, in the last year, they had sexual contact with a man who had sex with another man after 1977.

On July 22, 2013, Canada changed this policy so that MSM can donate blood if they have abstained from sexual contact with another man for the past 5 years. The deferral period for females is still 12 months if they have had sex with a man who has had sex with another man in the last 5 years, but there is no deferral if the man had sex with another man more than 5 years before.

To evaluate the impact of this policy change, Dr O’Brien and her colleagues assessed compliance with the MSM criteria before and after the change, as well as the number of HIV-positive blood donations before and after the change.

The researchers also assessed the number of donors who would have been deferred according to the old MSM criteria but donated blood under the new criteria.

MSM history

The researchers selected random male donors of whole blood each month from October 2012 to February 2013 (pre-change) and from October 2014 to February 2015 (post-change). These donors were invited to complete an anonymous online survey about their MSM history.

The survey was completed by 9669 donors before the policy change and 6881 donors after the change. There were 77 donors with MSM history before the change (20% first-time donors, 80% repeat) and 75 donors with MSM history after the change (22% first-time, 78% repeat).

Compliance with policy

After the change in policy for MSM blood donors, there was no significant change in the proportion of donors who had recent MSM history but donated anyway (non-compliant). Before the change, 0.37% of blood donors had an MSM partner in the last 5 years, compared to 0.43% after the change (P=0.54).

However, there was a significant change in the proportion of blood donors with MSM history further in the past. Before the MSM policy change, 0.42% of donors had an MSM partner but not in the last 5 years, compared to 0.66% of donors after the change (P=0.04).

“So we have an improvement in compliance, but it’s mainly because the donors are no longer deferrable,” Dr O’Brien explained.

“Donating while ineligible because of MSM history is actually quite rare, and the percentage of donors with MSM history in the last 5 years did not change when we changed the criteria. But we did see a modest increase in newly eligible MSM, so those that had more than 5 years since their last male-to-male sex.”

In all, there were 112 donors who were newly eligible due to the policy change and did, in fact, donate blood between July 22, 2013 and July 21, 2015. Five of these donors were females who had sexual contact with MSMs.

There were 70 “reinstated” donors in the first year after the policy change and 42 in the second year.

HIV-positive donations

The researchers monitored HIV rates in all blood donations from January 2010 to March 2015.

The rates of HIV-positive donations were as follows: 0.20 for 2010 (2/989,916), 0.50 for 2011 (5/995,122), 0.51 for 2012 (5/987,527), 0 (0/525,337) from January 1, 2013 to July 21, 2013 (before the policy change), 0.54 from July 22, 2013 to July 21, 2014 (5/929,656), and 0.22 from July 22, 2014 to July 21, 2015 (2/893,513).

“So absolutely no change in HIV rate following implementation of our 5-year deferral,” Dr O’Brien said.

In all, there were 7 HIV-positive donations after the policy change. Four were from male donors, and 3 were from females.

Three of the male donors (2 first-time donors, 1 repeat) denied having MSM risk factors, and 1 first-time male donor was aware he was HIV-positive at the time of donation. This man said he donated to determine if his HIV medication was working.

Two of the females were repeat donors, and 1 was a first-timer. The first-time donor did not acknowledge any MSM risk factors. One of the repeat donors had a sexual relationship with a bisexual male who was HIV-positive. The other repeat donor had multiple sexual partners, 1 of whom was known to be hepatitis C-positive.

Future policy change

Dr O’Brien noted that the LGBTQ community in Canada has advocated abolishing the deferral period for MSM blood donors or changing to a risk-based policy that would allow more individuals with MSM history to donate blood.

She said the combined blood services in Canada—Canadian Blood Services and Héma-Québec—are now considering a 12-month deferral period for individuals with MSM history.

“We’re pretty sure we’re going to go ahead,” she noted.

However, the groups must submit a policy request to Health Canada, which will ultimately make the decision.

*Data in the abstract differ from data presented at the meeting.

Red blood cells

Researchers say they can increase the production of red blood cells (RBCs) in the lab by targeting a single gene—SH2B3.

The team used RNA interference (RNAi) to turn down SH2B3 in human hematopoietic stem and progenitor cells (HSPCs) and increased the yield of RBCs about 3- to 7-fold.

They also used CRISPR/Cas9 genome editing to shut off SH2B3 in human embryonic stem cell (hESC) lines, increasing the yield of RBCs about 3-fold.

The researchers noted that the method involving hESCs would be easier to use for large-scale production of RBCs.

Vijay Sankaran, MD, PhD, of the Broad Institute in Cambridge, Massachusetts, and his colleagues conducted this research and reported the results in Cell Stem Cell.

The researchers homed in on their target gene, SH2B3, after genome sequencing data revealed naturally occurring variations in SH2B3. These variations reduce the gene’s activity and increase RBC production.

“There’s a variation in SH2B3 found in about 40% of people that leads to modestly higher red blood cell counts,” Dr Sankaran said. “But if you look at people with really high red blood cell levels, they often have rare SH2B3 mutations. That said to us that here is a target where you can partially or completely eliminate its function as a way of increasing red blood cells robustly.”

So Dr Sankaran and his colleagues set out to see if they could use SH2B3 as a target to increase the yield of lab-based RBC production processes (as opposed to tweaking cells in culture by adding cytokines and other factors).

To do this, they first used RNAi to turn down SH2B3 in donated adult HSPCs and HSPCs from umbilical cord blood.

The team’s data confirmed that shutting off SH2B3 with RNAi skews an HSPC’s profile of cell production to favor RBCs. Adult HSPCs treated with RNAi produced 3- to 5-fold more RBCs than controls. And RNAi-treated HSPCs from cord blood produced 5- to 7-fold more RBCs than controls.

Using multiple tests, the researchers found the RBCs produced by RNAi were essentially indistinguishable from control cells.

Dr Sankaran and his colleagues recognized that this approach would be very difficult to scale up to a level that could impact the clinical need for RBCs. So, in a separate set of experiments, they used CRISPR to permanently shut off SH2B3 in hESC lines, which can be readily renewed in a lab.

The team then treated the edited cells with a cocktail of factors known to encourage blood cell production. Under these conditions, the edited hESCs produced 3 times more RBCs than controls. Again, the team could find no significant differences between RBCs from the edited stem cells and controls.

Dr Sankaran believes that SH2B3 enforces some kind of upper limit on how much RBC precursors respond to calls for more RBC production.

“This is a nice approach because it removes the brakes that normally keep cells restrained and limit how much red blood cell precursors respond to different laboratory conditions,” he said.

Dr Sankaran also believes that, with further development, the combination of CRISPR and hESCs could increase the yields and reduce the costs of producing RBCs in the lab to the level where commercial-scale manufacture could be feasible.

“This is allowing us to get close to the cost of normal donor-derived blood units,” he said. “If we can get the costs down to about $2000 per unit, that’s a reasonable cost.”

Previous research has shown it is possible to produce transfusion-grade RBCs, but the costs ranged from $8000 to $15,000 per unit of blood.

Red blood cells

Researchers say they can increase the production of red blood cells (RBCs) in the lab by targeting a single gene—SH2B3.

The team used RNA interference (RNAi) to turn down SH2B3 in human hematopoietic stem and progenitor cells (HSPCs) and increased the yield of RBCs about 3- to 7-fold.

They also used CRISPR/Cas9 genome editing to shut off SH2B3 in human embryonic stem cell (hESC) lines, increasing the yield of RBCs about 3-fold.

The researchers noted that the method involving hESCs would be easier to use for large-scale production of RBCs.

Vijay Sankaran, MD, PhD, of the Broad Institute in Cambridge, Massachusetts, and his colleagues conducted this research and reported the results in Cell Stem Cell.

The researchers homed in on their target gene, SH2B3, after genome sequencing data revealed naturally occurring variations in SH2B3. These variations reduce the gene’s activity and increase RBC production.

“There’s a variation in SH2B3 found in about 40% of people that leads to modestly higher red blood cell counts,” Dr Sankaran said. “But if you look at people with really high red blood cell levels, they often have rare SH2B3 mutations. That said to us that here is a target where you can partially or completely eliminate its function as a way of increasing red blood cells robustly.”

So Dr Sankaran and his colleagues set out to see if they could use SH2B3 as a target to increase the yield of lab-based RBC production processes (as opposed to tweaking cells in culture by adding cytokines and other factors).

To do this, they first used RNAi to turn down SH2B3 in donated adult HSPCs and HSPCs from umbilical cord blood.

The team’s data confirmed that shutting off SH2B3 with RNAi skews an HSPC’s profile of cell production to favor RBCs. Adult HSPCs treated with RNAi produced 3- to 5-fold more RBCs than controls. And RNAi-treated HSPCs from cord blood produced 5- to 7-fold more RBCs than controls.

Using multiple tests, the researchers found the RBCs produced by RNAi were essentially indistinguishable from control cells.

Dr Sankaran and his colleagues recognized that this approach would be very difficult to scale up to a level that could impact the clinical need for RBCs. So, in a separate set of experiments, they used CRISPR to permanently shut off SH2B3 in hESC lines, which can be readily renewed in a lab.

The team then treated the edited cells with a cocktail of factors known to encourage blood cell production. Under these conditions, the edited hESCs produced 3 times more RBCs than controls. Again, the team could find no significant differences between RBCs from the edited stem cells and controls.

Dr Sankaran believes that SH2B3 enforces some kind of upper limit on how much RBC precursors respond to calls for more RBC production.

“This is a nice approach because it removes the brakes that normally keep cells restrained and limit how much red blood cell precursors respond to different laboratory conditions,” he said.

Dr Sankaran also believes that, with further development, the combination of CRISPR and hESCs could increase the yields and reduce the costs of producing RBCs in the lab to the level where commercial-scale manufacture could be feasible.

“This is allowing us to get close to the cost of normal donor-derived blood units,” he said. “If we can get the costs down to about $2000 per unit, that’s a reasonable cost.”

Previous research has shown it is possible to produce transfusion-grade RBCs, but the costs ranged from $8000 to $15,000 per unit of blood.

Red blood cells

Researchers say they can increase the production of red blood cells (RBCs) in the lab by targeting a single gene—SH2B3.

The team used RNA interference (RNAi) to turn down SH2B3 in human hematopoietic stem and progenitor cells (HSPCs) and increased the yield of RBCs about 3- to 7-fold.

They also used CRISPR/Cas9 genome editing to shut off SH2B3 in human embryonic stem cell (hESC) lines, increasing the yield of RBCs about 3-fold.

The researchers noted that the method involving hESCs would be easier to use for large-scale production of RBCs.

Vijay Sankaran, MD, PhD, of the Broad Institute in Cambridge, Massachusetts, and his colleagues conducted this research and reported the results in Cell Stem Cell.

The researchers homed in on their target gene, SH2B3, after genome sequencing data revealed naturally occurring variations in SH2B3. These variations reduce the gene’s activity and increase RBC production.

“There’s a variation in SH2B3 found in about 40% of people that leads to modestly higher red blood cell counts,” Dr Sankaran said. “But if you look at people with really high red blood cell levels, they often have rare SH2B3 mutations. That said to us that here is a target where you can partially or completely eliminate its function as a way of increasing red blood cells robustly.”

So Dr Sankaran and his colleagues set out to see if they could use SH2B3 as a target to increase the yield of lab-based RBC production processes (as opposed to tweaking cells in culture by adding cytokines and other factors).

To do this, they first used RNAi to turn down SH2B3 in donated adult HSPCs and HSPCs from umbilical cord blood.

The team’s data confirmed that shutting off SH2B3 with RNAi skews an HSPC’s profile of cell production to favor RBCs. Adult HSPCs treated with RNAi produced 3- to 5-fold more RBCs than controls. And RNAi-treated HSPCs from cord blood produced 5- to 7-fold more RBCs than controls.

Using multiple tests, the researchers found the RBCs produced by RNAi were essentially indistinguishable from control cells.

Dr Sankaran and his colleagues recognized that this approach would be very difficult to scale up to a level that could impact the clinical need for RBCs. So, in a separate set of experiments, they used CRISPR to permanently shut off SH2B3 in hESC lines, which can be readily renewed in a lab.

The team then treated the edited cells with a cocktail of factors known to encourage blood cell production. Under these conditions, the edited hESCs produced 3 times more RBCs than controls. Again, the team could find no significant differences between RBCs from the edited stem cells and controls.

Dr Sankaran believes that SH2B3 enforces some kind of upper limit on how much RBC precursors respond to calls for more RBC production.

“This is a nice approach because it removes the brakes that normally keep cells restrained and limit how much red blood cell precursors respond to different laboratory conditions,” he said.

Dr Sankaran also believes that, with further development, the combination of CRISPR and hESCs could increase the yields and reduce the costs of producing RBCs in the lab to the level where commercial-scale manufacture could be feasible.

“This is allowing us to get close to the cost of normal donor-derived blood units,” he said. “If we can get the costs down to about $2000 per unit, that’s a reasonable cost.”

Previous research has shown it is possible to produce transfusion-grade RBCs, but the costs ranged from $8000 to $15,000 per unit of blood.

Blood for transfusion

Photo by Elise Amendola

Patients undergoing cardiac surgery can safely receive transfusions with older red blood cells (RBCs), according to new research.

In many countries, RBCs can be stored for as long as 6 weeks before transfusion.

But a study published in 2008 suggested that transfusing RBCs stored for more than 2 weeks could increase the risk of serious complications.

Results of subsequent studies both supported and contradicted that finding.

The new study, published in JAMA, adds to the debate. The results suggest the duration of RBC storage does not affect the risk of death or serious complications after transfusion.

“There have literally been hundreds of studies conducted on this topic the past 5 or 6 years, none of which have been able to provide a definitive answer,” said Gustaf Edgren, MD, PhD, of Karolinska Institutet in Stockholm, Sweden.

In an attempt to change that, Dr Edgren and his colleagues conducted a large-scale study of transfusions among cardiac surgery patients in Sweden. National guidelines there require that the oldest available blood unit is allocated first.

The researchers analyzed registry data on patients who underwent coronary artery bypass graft surgery, heart valve surgery, or both between 1997 and 2012.

There were 47,071 patients who received transfusions at 9 different hospitals. Of these patients, 36.6% received RBCs stored for less than 14 days, 26.8%

received RBCs stored 14 to 27 days, 8.9% received RBCs stored 28 to 42

days, and 27.8% received RBCs of mixed age.

The researchers compared these patient groups, looking at the incidence of serious complications at 30 days and mortality at 30 days, 2 years, and 10 years.

They adjusted their analyses for potential confounding factors such as sex, age, blood group, and hospital. And they found no association between RBC storage duration and mortality or serious complications.

“This study is by far the largest investigation focusing on the issue of blood storage in this very sensitive patient group, and we find absolutely no hint of negative health effects associated with stored blood,”  said Ulrik Sartipy, MD, PhD, of Karolinska University Hospital.

“[W]e have been able to provide very firm reassurance that the current blood storage practices are safe,” Dr Edgren added.

Blood for transfusion

Photo by Elise Amendola

Patients undergoing cardiac surgery can safely receive transfusions with older red blood cells (RBCs), according to new research.

In many countries, RBCs can be stored for as long as 6 weeks before transfusion.

But a study published in 2008 suggested that transfusing RBCs stored for more than 2 weeks could increase the risk of serious complications.

Results of subsequent studies both supported and contradicted that finding.

The new study, published in JAMA, adds to the debate. The results suggest the duration of RBC storage does not affect the risk of death or serious complications after transfusion.

“There have literally been hundreds of studies conducted on this topic the past 5 or 6 years, none of which have been able to provide a definitive answer,” said Gustaf Edgren, MD, PhD, of Karolinska Institutet in Stockholm, Sweden.

In an attempt to change that, Dr Edgren and his colleagues conducted a large-scale study of transfusions among cardiac surgery patients in Sweden. National guidelines there require that the oldest available blood unit is allocated first.

The researchers analyzed registry data on patients who underwent coronary artery bypass graft surgery, heart valve surgery, or both between 1997 and 2012.

There were 47,071 patients who received transfusions at 9 different hospitals. Of these patients, 36.6% received RBCs stored for less than 14 days, 26.8%

received RBCs stored 14 to 27 days, 8.9% received RBCs stored 28 to 42

days, and 27.8% received RBCs of mixed age.

The researchers compared these patient groups, looking at the incidence of serious complications at 30 days and mortality at 30 days, 2 years, and 10 years.

They adjusted their analyses for potential confounding factors such as sex, age, blood group, and hospital. And they found no association between RBC storage duration and mortality or serious complications.

“This study is by far the largest investigation focusing on the issue of blood storage in this very sensitive patient group, and we find absolutely no hint of negative health effects associated with stored blood,”  said Ulrik Sartipy, MD, PhD, of Karolinska University Hospital.

“[W]e have been able to provide very firm reassurance that the current blood storage practices are safe,” Dr Edgren added.

Blood for transfusion

Photo by Elise Amendola

Patients undergoing cardiac surgery can safely receive transfusions with older red blood cells (RBCs), according to new research.

In many countries, RBCs can be stored for as long as 6 weeks before transfusion.

But a study published in 2008 suggested that transfusing RBCs stored for more than 2 weeks could increase the risk of serious complications.

Results of subsequent studies both supported and contradicted that finding.

The new study, published in JAMA, adds to the debate. The results suggest the duration of RBC storage does not affect the risk of death or serious complications after transfusion.

“There have literally been hundreds of studies conducted on this topic the past 5 or 6 years, none of which have been able to provide a definitive answer,” said Gustaf Edgren, MD, PhD, of Karolinska Institutet in Stockholm, Sweden.

In an attempt to change that, Dr Edgren and his colleagues conducted a large-scale study of transfusions among cardiac surgery patients in Sweden. National guidelines there require that the oldest available blood unit is allocated first.

The researchers analyzed registry data on patients who underwent coronary artery bypass graft surgery, heart valve surgery, or both between 1997 and 2012.

There were 47,071 patients who received transfusions at 9 different hospitals. Of these patients, 36.6% received RBCs stored for less than 14 days, 26.8%

received RBCs stored 14 to 27 days, 8.9% received RBCs stored 28 to 42

days, and 27.8% received RBCs of mixed age.

The researchers compared these patient groups, looking at the incidence of serious complications at 30 days and mortality at 30 days, 2 years, and 10 years.

They adjusted their analyses for potential confounding factors such as sex, age, blood group, and hospital. And they found no association between RBC storage duration and mortality or serious complications.

“This study is by far the largest investigation focusing on the issue of blood storage in this very sensitive patient group, and we find absolutely no hint of negative health effects associated with stored blood,”  said Ulrik Sartipy, MD, PhD, of Karolinska University Hospital.

“[W]e have been able to provide very firm reassurance that the current blood storage practices are safe,” Dr Edgren added.

Blood for transfusion

Photo by Juan D. Alfonso

CHICAGO—Researchers say an electronic tracking system has enabled a group of hospitals to significantly reduce the amount of blood transfused after operations.

This system also cut costs by an estimated $2.5 million over 2 years and contributed to lower infection rates without harming patients.

These results were presented at the 2015 Clinical Congress of the American College of Surgeons and published in the Journal of the American College of Surgeons.

In 2012, Intermountain Healthcare implemented the blood ordering and tracking system, along with a program to educate hospital staff, in 22 hospitals across Utah. This includes trauma centers, small rural hospitals, and large community medical centers.

Intermountain employs approximately 1200 physicians and 550 advanced practice clinicians, and another 3000 to 4000 independent physicians have privileges at Intermountain hospitals.

Before Intermountain implemented its blood tracking system, general surgeons, orthopedic surgeons, and urologists each used different hematocrit levels to order blood.

Now, Intermountain uses a consistent threshold across all disciplines—less than 23%. However, physicians can still order blood for patients with hematocrit above that threshold when they feel it is medically necessary.

Results

In 2011, 6% of all patients at Intermountain facilities received blood. Today, only 4% do, according to study author Mark J. Ott, MD, chief medical director of Intermountain Healthcare’s central region.

“So a third of our patients didn’t get blood who used to,” Dr Ott said. “That’s a giant change. That’s tens of thousands of units of blood a year that didn’t get used.”

Before the program started (January 1, 2012), Intermountain facilities transfused almost 50 units of packed red blood cells per 1000 patient days. By January 31, 2015, that rate had declined to about 35.5 units, a reduction of around 30%.

Over the same time period, the percentage of patients transfused with a hematocrit of 23% or greater decreased from 60% to 34%.

The researchers said these reductions in blood use reduced costs by about $2.5 million over the 2-year period, assuming each unit of packed red blood cells costs $300.

In addition, the rate of hospital-acquired infections for both the general hospital population and patients who received blood declined significantly over the 2-year period.

The overall infection rate fell from 1.66 to 0.81 per 1000 patient days. Among patients who received blood, infection rates declined around 33%.

Dr Ott noted that the reduction in infections was also impacted by other initiatives within the health system aimed at reducing surgical site infections and ambulating patients earlier after operations.

“So I cannot tell you that those decreases in hospital-acquired infections are solely due to patients receiving less blood, but it’s part of the picture,” he said. “And we did not see worse outcomes in patients.”

Blood for transfusion

Photo by Juan D. Alfonso

CHICAGO—Researchers say an electronic tracking system has enabled a group of hospitals to significantly reduce the amount of blood transfused after operations.

This system also cut costs by an estimated $2.5 million over 2 years and contributed to lower infection rates without harming patients.

These results were presented at the 2015 Clinical Congress of the American College of Surgeons and published in the Journal of the American College of Surgeons.

In 2012, Intermountain Healthcare implemented the blood ordering and tracking system, along with a program to educate hospital staff, in 22 hospitals across Utah. This includes trauma centers, small rural hospitals, and large community medical centers.

Intermountain employs approximately 1200 physicians and 550 advanced practice clinicians, and another 3000 to 4000 independent physicians have privileges at Intermountain hospitals.

Before Intermountain implemented its blood tracking system, general surgeons, orthopedic surgeons, and urologists each used different hematocrit levels to order blood.

Now, Intermountain uses a consistent threshold across all disciplines—less than 23%. However, physicians can still order blood for patients with hematocrit above that threshold when they feel it is medically necessary.

Results

In 2011, 6% of all patients at Intermountain facilities received blood. Today, only 4% do, according to study author Mark J. Ott, MD, chief medical director of Intermountain Healthcare’s central region.

“So a third of our patients didn’t get blood who used to,” Dr Ott said. “That’s a giant change. That’s tens of thousands of units of blood a year that didn’t get used.”

Before the program started (January 1, 2012), Intermountain facilities transfused almost 50 units of packed red blood cells per 1000 patient days. By January 31, 2015, that rate had declined to about 35.5 units, a reduction of around 30%.

Over the same time period, the percentage of patients transfused with a hematocrit of 23% or greater decreased from 60% to 34%.

The researchers said these reductions in blood use reduced costs by about $2.5 million over the 2-year period, assuming each unit of packed red blood cells costs $300.

In addition, the rate of hospital-acquired infections for both the general hospital population and patients who received blood declined significantly over the 2-year period.

The overall infection rate fell from 1.66 to 0.81 per 1000 patient days. Among patients who received blood, infection rates declined around 33%.

Dr Ott noted that the reduction in infections was also impacted by other initiatives within the health system aimed at reducing surgical site infections and ambulating patients earlier after operations.

“So I cannot tell you that those decreases in hospital-acquired infections are solely due to patients receiving less blood, but it’s part of the picture,” he said. “And we did not see worse outcomes in patients.”

Blood for transfusion

Photo by Juan D. Alfonso

CHICAGO—Researchers say an electronic tracking system has enabled a group of hospitals to significantly reduce the amount of blood transfused after operations.

This system also cut costs by an estimated $2.5 million over 2 years and contributed to lower infection rates without harming patients.

These results were presented at the 2015 Clinical Congress of the American College of Surgeons and published in the Journal of the American College of Surgeons.

In 2012, Intermountain Healthcare implemented the blood ordering and tracking system, along with a program to educate hospital staff, in 22 hospitals across Utah. This includes trauma centers, small rural hospitals, and large community medical centers.

Intermountain employs approximately 1200 physicians and 550 advanced practice clinicians, and another 3000 to 4000 independent physicians have privileges at Intermountain hospitals.

Before Intermountain implemented its blood tracking system, general surgeons, orthopedic surgeons, and urologists each used different hematocrit levels to order blood.

Now, Intermountain uses a consistent threshold across all disciplines—less than 23%. However, physicians can still order blood for patients with hematocrit above that threshold when they feel it is medically necessary.

Results

In 2011, 6% of all patients at Intermountain facilities received blood. Today, only 4% do, according to study author Mark J. Ott, MD, chief medical director of Intermountain Healthcare’s central region.

“So a third of our patients didn’t get blood who used to,” Dr Ott said. “That’s a giant change. That’s tens of thousands of units of blood a year that didn’t get used.”

Before the program started (January 1, 2012), Intermountain facilities transfused almost 50 units of packed red blood cells per 1000 patient days. By January 31, 2015, that rate had declined to about 35.5 units, a reduction of around 30%.

Over the same time period, the percentage of patients transfused with a hematocrit of 23% or greater decreased from 60% to 34%.

The researchers said these reductions in blood use reduced costs by about $2.5 million over the 2-year period, assuming each unit of packed red blood cells costs $300.

In addition, the rate of hospital-acquired infections for both the general hospital population and patients who received blood declined significantly over the 2-year period.

The overall infection rate fell from 1.66 to 0.81 per 1000 patient days. Among patients who received blood, infection rates declined around 33%.

Dr Ott noted that the reduction in infections was also impacted by other initiatives within the health system aimed at reducing surgical site infections and ambulating patients earlier after operations.

“So I cannot tell you that those decreases in hospital-acquired infections are solely due to patients receiving less blood, but it’s part of the picture,” he said. “And we did not see worse outcomes in patients.”

Blood for transfusion

Photo courtesy of UAB Hospital

VIENNA—New research suggests that having a higher body mass index (BMI) is associated with a decreased need for blood transfusion among patients undergoing hip or knee replacement surgery.

In this retrospective, single-center study, overweight and obese patients were less likely than patients with a normal BMI to require blood transfusions.

The investigators said these results add to the conflicting body of research examining the association between BMI and blood transfusions in this patient population.

The results were presented at the International Society for Technology in Arthroplasty Annual Congress.

“The results were surprising to us,” said investigator Craig Silverton, DO, of Henry Ford Health System in Detroit, Michigan.

“It goes against the normal thought process. It’s hard to explain, but one theory could be that heavier patients have larger blood volume than patients of normal weight.”

For this study, Dr Silverton and his colleagues evaluated 2399 patients, 1503 of whom underwent knee replacement and 896 of whom underwent hip surgery.

The investigators divided patients into 3 groups according to BMI: normal (BMI less than 25), overweight (BMI of 25 to 29.9), and obese (BMI more than 30).

As BMI increased, there was a significant increase in the estimated blood loss for both types of surgery.

Among hip surgery patients, the estimated blood loss was 268.2± 313.9 mL in patients with a normal BMI, 282.0 ± 208.7 mL in overweight patients, and 330.5 ± 302.4 mL in obese patients.

Among knee surgery patients, the estimated blood loss was 85.7 ± 153.8 mL in patients with a normal BMI, 90.5 ± 164.6 mL in overweight patients, and 89.4 ± 72.4 mL in obese patients.

However, with increasing BMI, there was a significant decrease in the estimated blood volume lost.

Among hip surgery patients, the estimated blood volume lost was 6.12% ± 8.12 in patients with a normal BMI, 4.92% ± 3.05 in overweight patients, and 4.50% ± 3.25 in obese patients.

Among knee surgery patients, the estimated blood volume lost was 2.05% ± 4.00 in patients with a normal BMI, 1.55% ± 2.73 in overweight patients, and 1.26% ± 1.01 in obese patients.

Likewise, there was a significant reduction in transfusion rates as BMI increased.

Among hip surgery patients, the transfusion rate was 34.8% for those with a normal BMI, 27.6% for those who were overweight, and 21.9% for obese patients.

Among knee surgery patients, the transfusion rate was 17.3% for those with a normal BMI, 11.4% for those who were overweight, and 8.3% for obese patients.

The investigators noted that there was no identifiable relationship between BMI and deep vein thrombosis, pulmonary embolism, myocardial infarction, length of hospital stay, 30-day readmission rate, or preoperative hemoglobin level.

There was a trend toward increased deep surgical site infections with increased BMI, but only among patients who underwent hip surgery.

Blood for transfusion

Photo courtesy of UAB Hospital

VIENNA—New research suggests that having a higher body mass index (BMI) is associated with a decreased need for blood transfusion among patients undergoing hip or knee replacement surgery.

In this retrospective, single-center study, overweight and obese patients were less likely than patients with a normal BMI to require blood transfusions.

The investigators said these results add to the conflicting body of research examining the association between BMI and blood transfusions in this patient population.

The results were presented at the International Society for Technology in Arthroplasty Annual Congress.

“The results were surprising to us,” said investigator Craig Silverton, DO, of Henry Ford Health System in Detroit, Michigan.

“It goes against the normal thought process. It’s hard to explain, but one theory could be that heavier patients have larger blood volume than patients of normal weight.”

For this study, Dr Silverton and his colleagues evaluated 2399 patients, 1503 of whom underwent knee replacement and 896 of whom underwent hip surgery.

The investigators divided patients into 3 groups according to BMI: normal (BMI less than 25), overweight (BMI of 25 to 29.9), and obese (BMI more than 30).

As BMI increased, there was a significant increase in the estimated blood loss for both types of surgery.

Among hip surgery patients, the estimated blood loss was 268.2± 313.9 mL in patients with a normal BMI, 282.0 ± 208.7 mL in overweight patients, and 330.5 ± 302.4 mL in obese patients.

Among knee surgery patients, the estimated blood loss was 85.7 ± 153.8 mL in patients with a normal BMI, 90.5 ± 164.6 mL in overweight patients, and 89.4 ± 72.4 mL in obese patients.

However, with increasing BMI, there was a significant decrease in the estimated blood volume lost.

Among hip surgery patients, the estimated blood volume lost was 6.12% ± 8.12 in patients with a normal BMI, 4.92% ± 3.05 in overweight patients, and 4.50% ± 3.25 in obese patients.

Among knee surgery patients, the estimated blood volume lost was 2.05% ± 4.00 in patients with a normal BMI, 1.55% ± 2.73 in overweight patients, and 1.26% ± 1.01 in obese patients.

Likewise, there was a significant reduction in transfusion rates as BMI increased.

Among hip surgery patients, the transfusion rate was 34.8% for those with a normal BMI, 27.6% for those who were overweight, and 21.9% for obese patients.

Among knee surgery patients, the transfusion rate was 17.3% for those with a normal BMI, 11.4% for those who were overweight, and 8.3% for obese patients.

The investigators noted that there was no identifiable relationship between BMI and deep vein thrombosis, pulmonary embolism, myocardial infarction, length of hospital stay, 30-day readmission rate, or preoperative hemoglobin level.

There was a trend toward increased deep surgical site infections with increased BMI, but only among patients who underwent hip surgery.

Blood for transfusion

Photo courtesy of UAB Hospital

VIENNA—New research suggests that having a higher body mass index (BMI) is associated with a decreased need for blood transfusion among patients undergoing hip or knee replacement surgery.

In this retrospective, single-center study, overweight and obese patients were less likely than patients with a normal BMI to require blood transfusions.

The investigators said these results add to the conflicting body of research examining the association between BMI and blood transfusions in this patient population.

The results were presented at the International Society for Technology in Arthroplasty Annual Congress.

“The results were surprising to us,” said investigator Craig Silverton, DO, of Henry Ford Health System in Detroit, Michigan.

“It goes against the normal thought process. It’s hard to explain, but one theory could be that heavier patients have larger blood volume than patients of normal weight.”

For this study, Dr Silverton and his colleagues evaluated 2399 patients, 1503 of whom underwent knee replacement and 896 of whom underwent hip surgery.

The investigators divided patients into 3 groups according to BMI: normal (BMI less than 25), overweight (BMI of 25 to 29.9), and obese (BMI more than 30).

As BMI increased, there was a significant increase in the estimated blood loss for both types of surgery.

Among hip surgery patients, the estimated blood loss was 268.2± 313.9 mL in patients with a normal BMI, 282.0 ± 208.7 mL in overweight patients, and 330.5 ± 302.4 mL in obese patients.

Among knee surgery patients, the estimated blood loss was 85.7 ± 153.8 mL in patients with a normal BMI, 90.5 ± 164.6 mL in overweight patients, and 89.4 ± 72.4 mL in obese patients.

However, with increasing BMI, there was a significant decrease in the estimated blood volume lost.

Among hip surgery patients, the estimated blood volume lost was 6.12% ± 8.12 in patients with a normal BMI, 4.92% ± 3.05 in overweight patients, and 4.50% ± 3.25 in obese patients.

Among knee surgery patients, the estimated blood volume lost was 2.05% ± 4.00 in patients with a normal BMI, 1.55% ± 2.73 in overweight patients, and 1.26% ± 1.01 in obese patients.

Likewise, there was a significant reduction in transfusion rates as BMI increased.

Among hip surgery patients, the transfusion rate was 34.8% for those with a normal BMI, 27.6% for those who were overweight, and 21.9% for obese patients.

Among knee surgery patients, the transfusion rate was 17.3% for those with a normal BMI, 11.4% for those who were overweight, and 8.3% for obese patients.

The investigators noted that there was no identifiable relationship between BMI and deep vein thrombosis, pulmonary embolism, myocardial infarction, length of hospital stay, 30-day readmission rate, or preoperative hemoglobin level.

There was a trend toward increased deep surgical site infections with increased BMI, but only among patients who underwent hip surgery.

Blood for transfusion

Photo by Elise Amendola

A young trauma patient’s hematocrit level at hospital admission may predict the need for transfusion, new research suggests.

Results of this retrospective, single-center study indicate that children and adolescents with a hematocrit level of 35% or less at admission are more likely than their peers with higher hematocrit levels to require a transfusion after trauma.

The study was published in the Journal of Trauma and Acute Care Surgery.

“A quick and cost-effective measure, such as admission hematocrit, to identify pediatric patients who are at a high risk for bleeding could provide a critical improvement in optimizing care for children, while reducing costs,” said study author Christopher P. Gayer, MD, PhD, of Children's Hospital Los Angeles (CHLA) in California.

For this research, Dr Gayer and his colleagues examined the medical records of all patients, ages 0 to 17, who presented to the level 1 pediatric trauma center at CHLA between 2005 and 2013.

Of all the patients, 1341 had hematocrit measured at admission. The researchers divided this group into patients who required an intervention—transfusion or operation—for their bleeding (n=93) and those who did not (n=1248).

The mean hematocrit was 38.0 for patients who did not require an intervention and 34.3 for those who did (P<0.01). The mean hematocrit was 26.9 in patients who required a transfusion secondary to bleeding and 36.0 in those who required an operative intervention for nonhemostatic indications (P<0.01).

The researchers then analyzed a subset of patients who had an abdominal CT scan, as these patients had a definitive presence or absence of intra-abdominal injury. There was a significant decrease in admission hematocrit between patients who required a transfusion for an intra-abdominal injury and those who did not—29% and 37%, respectively (P<0.01).

Serial hematocrit values remained significantly lower in the patients who required a transfusion up to 67 hours after admission (P=0.04). The researchers said this suggests that hematocrit is a valuable predictor for requiring a transfusion at least 2 days after an injury, and it may be useful for patients presenting well after their initial injury.

The team then evaluated whether an admission hematocrit cutoff of 35% or less could predict the need for transfusion. For all patients, a cutoff of 35% or less had a sensitivity of 94%, specificity of 77%, positive-predictive value of 5%, and negative predictive value of 99.9%.

In patients who had an abdominal CT, a cutoff hematocrit of 35% or less had a sensitivity of 90%, specificity of 76%, positive predictive value of 21%, and negative predictive value of 99%.

These results led the researchers to conclude that this hematocrit cutoff may be a reliable screening tool.

“Admission hematocrit can be done rapidly in the trauma bay, is relatively inexpensive, causes minimal harm, and can aid in critical decision-making and rapid identification of occult bleeding,” said study author Jamie Golden, MD, of CHLA.

“Our results show that a hematocrit level of less than 35% on admission predicts a greater likelihood for the need of transfusion in pediatric blunt trauma patients.”

The researchers stressed that a doctor's concern in the face of clinical signs of hemorrhagic shock should always take priority over lab data. However, a repeat hematocrit can be quickly and easily performed if clinically indicated.

They added that the results of their study require validation in a prospective, multicenter study.

Blood for transfusion

Photo by Elise Amendola

A young trauma patient’s hematocrit level at hospital admission may predict the need for transfusion, new research suggests.

Results of this retrospective, single-center study indicate that children and adolescents with a hematocrit level of 35% or less at admission are more likely than their peers with higher hematocrit levels to require a transfusion after trauma.

The study was published in the Journal of Trauma and Acute Care Surgery.

“A quick and cost-effective measure, such as admission hematocrit, to identify pediatric patients who are at a high risk for bleeding could provide a critical improvement in optimizing care for children, while reducing costs,” said study author Christopher P. Gayer, MD, PhD, of Children's Hospital Los Angeles (CHLA) in California.

For this research, Dr Gayer and his colleagues examined the medical records of all patients, ages 0 to 17, who presented to the level 1 pediatric trauma center at CHLA between 2005 and 2013.

Of all the patients, 1341 had hematocrit measured at admission. The researchers divided this group into patients who required an intervention—transfusion or operation—for their bleeding (n=93) and those who did not (n=1248).

The mean hematocrit was 38.0 for patients who did not require an intervention and 34.3 for those who did (P<0.01). The mean hematocrit was 26.9 in patients who required a transfusion secondary to bleeding and 36.0 in those who required an operative intervention for nonhemostatic indications (P<0.01).

The researchers then analyzed a subset of patients who had an abdominal CT scan, as these patients had a definitive presence or absence of intra-abdominal injury. There was a significant decrease in admission hematocrit between patients who required a transfusion for an intra-abdominal injury and those who did not—29% and 37%, respectively (P<0.01).

Serial hematocrit values remained significantly lower in the patients who required a transfusion up to 67 hours after admission (P=0.04). The researchers said this suggests that hematocrit is a valuable predictor for requiring a transfusion at least 2 days after an injury, and it may be useful for patients presenting well after their initial injury.

The team then evaluated whether an admission hematocrit cutoff of 35% or less could predict the need for transfusion. For all patients, a cutoff of 35% or less had a sensitivity of 94%, specificity of 77%, positive-predictive value of 5%, and negative predictive value of 99.9%.

In patients who had an abdominal CT, a cutoff hematocrit of 35% or less had a sensitivity of 90%, specificity of 76%, positive predictive value of 21%, and negative predictive value of 99%.

These results led the researchers to conclude that this hematocrit cutoff may be a reliable screening tool.

“Admission hematocrit can be done rapidly in the trauma bay, is relatively inexpensive, causes minimal harm, and can aid in critical decision-making and rapid identification of occult bleeding,” said study author Jamie Golden, MD, of CHLA.

“Our results show that a hematocrit level of less than 35% on admission predicts a greater likelihood for the need of transfusion in pediatric blunt trauma patients.”

The researchers stressed that a doctor's concern in the face of clinical signs of hemorrhagic shock should always take priority over lab data. However, a repeat hematocrit can be quickly and easily performed if clinically indicated.

They added that the results of their study require validation in a prospective, multicenter study.

Blood for transfusion

Photo by Elise Amendola

A young trauma patient’s hematocrit level at hospital admission may predict the need for transfusion, new research suggests.

Results of this retrospective, single-center study indicate that children and adolescents with a hematocrit level of 35% or less at admission are more likely than their peers with higher hematocrit levels to require a transfusion after trauma.

The study was published in the Journal of Trauma and Acute Care Surgery.

“A quick and cost-effective measure, such as admission hematocrit, to identify pediatric patients who are at a high risk for bleeding could provide a critical improvement in optimizing care for children, while reducing costs,” said study author Christopher P. Gayer, MD, PhD, of Children's Hospital Los Angeles (CHLA) in California.

For this research, Dr Gayer and his colleagues examined the medical records of all patients, ages 0 to 17, who presented to the level 1 pediatric trauma center at CHLA between 2005 and 2013.

Of all the patients, 1341 had hematocrit measured at admission. The researchers divided this group into patients who required an intervention—transfusion or operation—for their bleeding (n=93) and those who did not (n=1248).

The mean hematocrit was 38.0 for patients who did not require an intervention and 34.3 for those who did (P<0.01). The mean hematocrit was 26.9 in patients who required a transfusion secondary to bleeding and 36.0 in those who required an operative intervention for nonhemostatic indications (P<0.01).

The researchers then analyzed a subset of patients who had an abdominal CT scan, as these patients had a definitive presence or absence of intra-abdominal injury. There was a significant decrease in admission hematocrit between patients who required a transfusion for an intra-abdominal injury and those who did not—29% and 37%, respectively (P<0.01).

Serial hematocrit values remained significantly lower in the patients who required a transfusion up to 67 hours after admission (P=0.04). The researchers said this suggests that hematocrit is a valuable predictor for requiring a transfusion at least 2 days after an injury, and it may be useful for patients presenting well after their initial injury.

The team then evaluated whether an admission hematocrit cutoff of 35% or less could predict the need for transfusion. For all patients, a cutoff of 35% or less had a sensitivity of 94%, specificity of 77%, positive-predictive value of 5%, and negative predictive value of 99.9%.

In patients who had an abdominal CT, a cutoff hematocrit of 35% or less had a sensitivity of 90%, specificity of 76%, positive predictive value of 21%, and negative predictive value of 99%.

These results led the researchers to conclude that this hematocrit cutoff may be a reliable screening tool.

“Admission hematocrit can be done rapidly in the trauma bay, is relatively inexpensive, causes minimal harm, and can aid in critical decision-making and rapid identification of occult bleeding,” said study author Jamie Golden, MD, of CHLA.

“Our results show that a hematocrit level of less than 35% on admission predicts a greater likelihood for the need of transfusion in pediatric blunt trauma patients.”

The researchers stressed that a doctor's concern in the face of clinical signs of hemorrhagic shock should always take priority over lab data. However, a repeat hematocrit can be quickly and easily performed if clinically indicated.

They added that the results of their study require validation in a prospective, multicenter study.

Blood for transfusion

Photo courtesy of UAB Hospital

Scientists say they have discovered a new virus that can be transmitted through the blood supply.

It is currently unclear whether the virus is harmful or not, but researchers found that it shares genetic features with hepatitis C virus (HCV) and human

pegivirus (HPgV), which was formerly known as hepatitis G virus.

The new virus, which the researchers have named human hepegivirus-1 (HHpgV-1), is described in the journal mBio.

“HHpgV-1 is unique because it shares genetic similarity with both highly pathogenic HCV and the apparently non-pathogenic HPgV,” said study author Amit Kapoor, PhD, of Columbia University in New York, New York. “People need to be aware of this new infection in humans.”

To identify HHpgV-1, Dr Kapoor and his colleagues performed high-throughput sequencing on blood samples from 46 individuals in the Transfusion-Transmitted Viruses Study. The samples were collected between July 1974 and June 1980.

The researchers analyzed samples both pre- and post-transfusion and, along with a variety of known viruses, they identified HHpgV-1 in 2 individuals.

The virus was only present in post-transfusion samples, and additional tests showed that both patients were able to clear HHpgV-1.

Genetic analysis revealed that the virus was related to HCV and HPgV. Genomic testing of 70 additional individuals in the Transfusion-Transmitted Viruses Study did not detect further cases of HHpgV-1.

The researchers also performed high-throughput sequencing on samples from 106 individuals in the Multicenter Hemophilia Cohort Study who received plasma-derived clotting factor concentrates.

The team identified HHpgV-1 in 2 individuals, one of whom had persistent long-term infection (5.4 years).

“We just don’t know how many viruses are transmitted through the blood supply,” Dr Kapoor said. “There are so many viruses out there, and they need to be characterized in order to ensure that transfusions are safe.”

He said the next steps are to determine the prevalence of HHpgV-1 and whether it causes disease. If it causes disease, screening the blood supply for the virus will be appropriate.

“Ultimately, once we know more about this, we will look for the presence of this virus in people with certain diseases,” Dr Kapoor said.

“The unusually high infection prevalence of HCV, HBV, and HIV in hemophilia patients and other transfusion recipients could have been prevented by earlier identification of these viruses and development of accurate diagnostic assays.”

Blood for transfusion

Photo courtesy of UAB Hospital

Scientists say they have discovered a new virus that can be transmitted through the blood supply.

It is currently unclear whether the virus is harmful or not, but researchers found that it shares genetic features with hepatitis C virus (HCV) and human

pegivirus (HPgV), which was formerly known as hepatitis G virus.

The new virus, which the researchers have named human hepegivirus-1 (HHpgV-1), is described in the journal mBio.

“HHpgV-1 is unique because it shares genetic similarity with both highly pathogenic HCV and the apparently non-pathogenic HPgV,” said study author Amit Kapoor, PhD, of Columbia University in New York, New York. “People need to be aware of this new infection in humans.”

To identify HHpgV-1, Dr Kapoor and his colleagues performed high-throughput sequencing on blood samples from 46 individuals in the Transfusion-Transmitted Viruses Study. The samples were collected between July 1974 and June 1980.

The researchers analyzed samples both pre- and post-transfusion and, along with a variety of known viruses, they identified HHpgV-1 in 2 individuals.

The virus was only present in post-transfusion samples, and additional tests showed that both patients were able to clear HHpgV-1.

Genetic analysis revealed that the virus was related to HCV and HPgV. Genomic testing of 70 additional individuals in the Transfusion-Transmitted Viruses Study did not detect further cases of HHpgV-1.

The researchers also performed high-throughput sequencing on samples from 106 individuals in the Multicenter Hemophilia Cohort Study who received plasma-derived clotting factor concentrates.

The team identified HHpgV-1 in 2 individuals, one of whom had persistent long-term infection (5.4 years).

“We just don’t know how many viruses are transmitted through the blood supply,” Dr Kapoor said. “There are so many viruses out there, and they need to be characterized in order to ensure that transfusions are safe.”

He said the next steps are to determine the prevalence of HHpgV-1 and whether it causes disease. If it causes disease, screening the blood supply for the virus will be appropriate.

“Ultimately, once we know more about this, we will look for the presence of this virus in people with certain diseases,” Dr Kapoor said.

“The unusually high infection prevalence of HCV, HBV, and HIV in hemophilia patients and other transfusion recipients could have been prevented by earlier identification of these viruses and development of accurate diagnostic assays.”

Blood for transfusion

Photo courtesy of UAB Hospital

Scientists say they have discovered a new virus that can be transmitted through the blood supply.

It is currently unclear whether the virus is harmful or not, but researchers found that it shares genetic features with hepatitis C virus (HCV) and human

pegivirus (HPgV), which was formerly known as hepatitis G virus.

The new virus, which the researchers have named human hepegivirus-1 (HHpgV-1), is described in the journal mBio.

“HHpgV-1 is unique because it shares genetic similarity with both highly pathogenic HCV and the apparently non-pathogenic HPgV,” said study author Amit Kapoor, PhD, of Columbia University in New York, New York. “People need to be aware of this new infection in humans.”

To identify HHpgV-1, Dr Kapoor and his colleagues performed high-throughput sequencing on blood samples from 46 individuals in the Transfusion-Transmitted Viruses Study. The samples were collected between July 1974 and June 1980.

The researchers analyzed samples both pre- and post-transfusion and, along with a variety of known viruses, they identified HHpgV-1 in 2 individuals.

The virus was only present in post-transfusion samples, and additional tests showed that both patients were able to clear HHpgV-1.

Genetic analysis revealed that the virus was related to HCV and HPgV. Genomic testing of 70 additional individuals in the Transfusion-Transmitted Viruses Study did not detect further cases of HHpgV-1.

The researchers also performed high-throughput sequencing on samples from 106 individuals in the Multicenter Hemophilia Cohort Study who received plasma-derived clotting factor concentrates.

The team identified HHpgV-1 in 2 individuals, one of whom had persistent long-term infection (5.4 years).

“We just don’t know how many viruses are transmitted through the blood supply,” Dr Kapoor said. “There are so many viruses out there, and they need to be characterized in order to ensure that transfusions are safe.”

He said the next steps are to determine the prevalence of HHpgV-1 and whether it causes disease. If it causes disease, screening the blood supply for the virus will be appropriate.

“Ultimately, once we know more about this, we will look for the presence of this virus in people with certain diseases,” Dr Kapoor said.

“The unusually high infection prevalence of HCV, HBV, and HIV in hemophilia patients and other transfusion recipients could have been prevented by earlier identification of these viruses and development of accurate diagnostic assays.”