Diagnosis: ABO Mismatched Hematopoietic Progenitor Cell Transplantation
• Although the earliest hematopoietic progenitor cells (HPCs) do not express the A and/or B antigens, more committed cells of the erythroid lineage express these antigens.
• Delayed red blood cell engraftment is a potential adverse consequence of a major ABO incompatibility.
• Delayed engraftment is due to production anti-A and/or anti-B antibodies by residual plasma cells in the recipient that survive the preparative conditioning regimen.
In the context of a major ABO mismatched HPCtransplant, an acute hemolytic reaction at the time of HPC infusion may also occur due to the presence of ABO-incompatible red blood cells in the donor product and circulating anti-A and/or anti-B antibodies in the recipient.
Red blood cells can be depleted from the donor product in the setting of a major ABO mismatched HPCtransplant, typically by performing simple red cell depletion, density gradient red cell depletion, or CD34 selection.
