Platelet transfusion refractoriness associated with HPA-1a (Pl(A1)) alloantibody without coexistent HLA antibodies successfully treated with antigen-negative platelet transfusions.

BACKGROUND: Alloimmune-mediated refractoriness to platelet transfusion is most commonly due to antibody to HLA antigens in multiply transfused or multiparous patients. Published reports of poor transfusion response due to antibodies to platelet-specific antigens are rare and often confounded by the presence of coexistent antibodies against HLA antigens. CASE REPORT: A case is presented of a multiparous woman with acute myelogenous leukemia whose sole cause of transfusion refractoriness was antibody to platelet antigen HPA-1a. She responded dramatically to HPA-1a-negative platelet transfusion. CONCLUSION: This case provides strong serologic and clinical evidence that platelet transfusion refractoriness may result from antibodies to platelet-specific antigens.