Platelet Transfusions From HL-A Compatible Unrelated Donors to Alloimmunized Patients

Abstract

Patients needing long-term platelet transfusion support become alloimmunized to transplantation (HL-A) antigens present in random-donor blood products, which results in refractoriness to platelets from unselected donors. Three thousand HL-A typed donors were used to evaluate the effectiveness of selecting unrelated platelet donors for alloimmunized patients by donor-recipient lymphocyte HL-A compatibility. Platelet transfusions from HL-A compatible donors resulted in increased platelet increments after transfusion. There was a positive correlation between the degree of donor-recipient HL-A compatibility and the transfusion response; the responses to platelets from A-matched donors (HL-A identical) and B-1-matched donors (HL-A compatible, one recipient antigen not present in the donor) were similar to platelet transfusions from HL-A identical siblings. ABO-incompatibility of HL-A compatible platelet donors did not affect the posttransfusion platelet increments. HL-A compatible platelet donors can be used effectively for transfusion support of alloimmunized patients.