Background: Alloantibodies against human platelet antigen (HPA)-15 are sometimes detected in patients with platelet transfusion refractoriness (PTR); however, little is known about their impact on PTR.
Study Design And Methods: Two patients who possessed HPA-15 alloantibodies (Patient 1, anti-HPA-15b; Patient 2, anti-HPA-15a) and human leukocyte antigen (HLA) antibodies were enrolled. The efficacy of HPA-15-compatible vs -incompatible platelet transfusion was compared by focusing on ABO- and HLA-matched transfusions on the basis of the 24-hour corrected count increment (CCI-24 hours) for platelets.