User login
ATLANTA – Matching red cell products to sickle-cell disease (SCD) patients with rare Rh antibodies can be accomplished with a little fancy stem cell footwork and some genetic legerdemain, investigators report.
to produce a renewable source of red cell reagents and potentially universal infusion products for patients with SCD.
“It has been more than 10 years since iPSCs have been available, but we have yet to see applications for blood diseases that improve how we care for our patients,” Dr. Chou said in a statement. “Using this panel, we would be able to more quickly identify what antibodies the patient has made, informing us what kind of blood we have to give them. It means we’ll be able to improve their ability to be transfused safely and reduce delays in their care.”
Up to half of all patients with SCD who require chronic transfusions may develop antibodies to allogeneic blood products, but identifying inactivating antibodies in a given patient can be both challenging and time consuming, due to a paucity of the appropriate reagent red cells, Dr. Chou and her colleagues reported.
The investigators previously reported that despite receiving transfusions from Rh-matched minority donors, patients with SCD have a high prevalence of red blood cell alloimmunization, and that Rh antibodies are the most common type of antibody in SCD patients, with about 33% of Rh antibodies associated with delayed transfusion reactions (Blood. 2013 Aug 8;122:1062-71; doi: 10.1182/blood-2013-03-490623).
It is both costly and time consuming to genotype donated blood for Rh antigens in order to match a low-antigen product to a specific patient. Instead, the investigators identified a workaround involving reprogramming or genetically engineering iPSCs from donors with rare antigen profiles, with the goal of creating a standard panel of red cell reagents that could reliably and quickly identify SCD patients with complex antibodies.
They used CRISPR/Cas9 gene-editing techniques to modify existing iPSCs to include Rh null cells, other cells lacking all or part of certain high-prevalence Rh antigens, and low prevalence novel antigens.
The investigators then showed that they could induce hematopoietic differentiation of their customized iPSCs through a three-step process and demonstrated that, as they had expected, the engineered antibodies were able to more accurately type Rh in gel card assays than did off-the-shelf commercial assays.
“We have designed a panel of customized iPSCs reprogrammed from rare donors or genetically engineered to express rare blood group antigen phenotypes or combinations that are difficult or impossible to find as donor red cells. Any number of combinations not found in natural populations can be produced and generated in quantities sufficient for reagents,” Dr. Chou said.
They also asserted that iPSC-derived red blood cells (iRBCs) produced from their customized iPSCs could be used with standard blood bank assays as a potential means of streamlining and standardizing the antibody identification process in alloimmunized patients with complex antibody specificities.
“In the future, when technology for scale-up is available, Rh null iRBCs could be used as ‘universal’ donor cells for future therapeutic applications,” the reseachers wrote.
The study was supported by the National Institutes of Health/National Heart Lung and Blood Institute. The authors reported having no conflicts of interest.
SOURCE: Chou S et al. ASH 2017 Abstract 3
ATLANTA – Matching red cell products to sickle-cell disease (SCD) patients with rare Rh antibodies can be accomplished with a little fancy stem cell footwork and some genetic legerdemain, investigators report.
to produce a renewable source of red cell reagents and potentially universal infusion products for patients with SCD.
“It has been more than 10 years since iPSCs have been available, but we have yet to see applications for blood diseases that improve how we care for our patients,” Dr. Chou said in a statement. “Using this panel, we would be able to more quickly identify what antibodies the patient has made, informing us what kind of blood we have to give them. It means we’ll be able to improve their ability to be transfused safely and reduce delays in their care.”
Up to half of all patients with SCD who require chronic transfusions may develop antibodies to allogeneic blood products, but identifying inactivating antibodies in a given patient can be both challenging and time consuming, due to a paucity of the appropriate reagent red cells, Dr. Chou and her colleagues reported.
The investigators previously reported that despite receiving transfusions from Rh-matched minority donors, patients with SCD have a high prevalence of red blood cell alloimmunization, and that Rh antibodies are the most common type of antibody in SCD patients, with about 33% of Rh antibodies associated with delayed transfusion reactions (Blood. 2013 Aug 8;122:1062-71; doi: 10.1182/blood-2013-03-490623).
It is both costly and time consuming to genotype donated blood for Rh antigens in order to match a low-antigen product to a specific patient. Instead, the investigators identified a workaround involving reprogramming or genetically engineering iPSCs from donors with rare antigen profiles, with the goal of creating a standard panel of red cell reagents that could reliably and quickly identify SCD patients with complex antibodies.
They used CRISPR/Cas9 gene-editing techniques to modify existing iPSCs to include Rh null cells, other cells lacking all or part of certain high-prevalence Rh antigens, and low prevalence novel antigens.
The investigators then showed that they could induce hematopoietic differentiation of their customized iPSCs through a three-step process and demonstrated that, as they had expected, the engineered antibodies were able to more accurately type Rh in gel card assays than did off-the-shelf commercial assays.
“We have designed a panel of customized iPSCs reprogrammed from rare donors or genetically engineered to express rare blood group antigen phenotypes or combinations that are difficult or impossible to find as donor red cells. Any number of combinations not found in natural populations can be produced and generated in quantities sufficient for reagents,” Dr. Chou said.
They also asserted that iPSC-derived red blood cells (iRBCs) produced from their customized iPSCs could be used with standard blood bank assays as a potential means of streamlining and standardizing the antibody identification process in alloimmunized patients with complex antibody specificities.
“In the future, when technology for scale-up is available, Rh null iRBCs could be used as ‘universal’ donor cells for future therapeutic applications,” the reseachers wrote.
The study was supported by the National Institutes of Health/National Heart Lung and Blood Institute. The authors reported having no conflicts of interest.
SOURCE: Chou S et al. ASH 2017 Abstract 3
ATLANTA – Matching red cell products to sickle-cell disease (SCD) patients with rare Rh antibodies can be accomplished with a little fancy stem cell footwork and some genetic legerdemain, investigators report.
to produce a renewable source of red cell reagents and potentially universal infusion products for patients with SCD.
“It has been more than 10 years since iPSCs have been available, but we have yet to see applications for blood diseases that improve how we care for our patients,” Dr. Chou said in a statement. “Using this panel, we would be able to more quickly identify what antibodies the patient has made, informing us what kind of blood we have to give them. It means we’ll be able to improve their ability to be transfused safely and reduce delays in their care.”
Up to half of all patients with SCD who require chronic transfusions may develop antibodies to allogeneic blood products, but identifying inactivating antibodies in a given patient can be both challenging and time consuming, due to a paucity of the appropriate reagent red cells, Dr. Chou and her colleagues reported.
The investigators previously reported that despite receiving transfusions from Rh-matched minority donors, patients with SCD have a high prevalence of red blood cell alloimmunization, and that Rh antibodies are the most common type of antibody in SCD patients, with about 33% of Rh antibodies associated with delayed transfusion reactions (Blood. 2013 Aug 8;122:1062-71; doi: 10.1182/blood-2013-03-490623).
It is both costly and time consuming to genotype donated blood for Rh antigens in order to match a low-antigen product to a specific patient. Instead, the investigators identified a workaround involving reprogramming or genetically engineering iPSCs from donors with rare antigen profiles, with the goal of creating a standard panel of red cell reagents that could reliably and quickly identify SCD patients with complex antibodies.
They used CRISPR/Cas9 gene-editing techniques to modify existing iPSCs to include Rh null cells, other cells lacking all or part of certain high-prevalence Rh antigens, and low prevalence novel antigens.
The investigators then showed that they could induce hematopoietic differentiation of their customized iPSCs through a three-step process and demonstrated that, as they had expected, the engineered antibodies were able to more accurately type Rh in gel card assays than did off-the-shelf commercial assays.
“We have designed a panel of customized iPSCs reprogrammed from rare donors or genetically engineered to express rare blood group antigen phenotypes or combinations that are difficult or impossible to find as donor red cells. Any number of combinations not found in natural populations can be produced and generated in quantities sufficient for reagents,” Dr. Chou said.
They also asserted that iPSC-derived red blood cells (iRBCs) produced from their customized iPSCs could be used with standard blood bank assays as a potential means of streamlining and standardizing the antibody identification process in alloimmunized patients with complex antibody specificities.
“In the future, when technology for scale-up is available, Rh null iRBCs could be used as ‘universal’ donor cells for future therapeutic applications,” the reseachers wrote.
The study was supported by the National Institutes of Health/National Heart Lung and Blood Institute. The authors reported having no conflicts of interest.
SOURCE: Chou S et al. ASH 2017 Abstract 3
REPORTING FROM ASH 2017
Key clinical point:. Customized induced pluripotent stem cells (iPSCs) could help to better and more rapidly match sickle-cell disease patients with appropriate transfusion products.
Major finding: Engineered iPSCs accurately typed Rh in iPSC-derived red blood cells in gel card assays.
Data source: Proof of concept in vitro study.
Disclosures: The study was supported by the National Institutes of Health/National Heart Lung and Blood Institute. The authors reported having no conflicts of interest.
Source: Chou S et al. ASH 2017 Abstract 3