Posttransfusion purpura: Therapeutic failure of PlAl‐negative platelet transfusion

Abstract

The effect of platelet type‐specific transfusion in posttranfusion purpura is reported. Seven days after receiving 4 units of whole blood during total hip replacement a 69‐year‐old woman developed fulminant thrombocytopenic purpura. Her undiluted serum inhibited the clot retraction of Pl^Al‐positive, but not Pl^Al‐negative blood. Anti‐Pl^Al titer of her serum, determined by ⁵¹Cr platelet lysis technique, was 1:64. The serum had no lytic activity against platelet‐rich plasma from two Pl^Al‐negative donors. No anti‐HLA antibody was detectable in the serum by lymphocytotoxicity technique, and serum obtained prior to transfusions had no platelet lytic activity. Four units of Pl^Al‐negative platelet concentrate were administered, the first instance in which this treatment has been used. No rise in platelet count ensued, and the patient succumbed to purpura. Exchange transfusion or plasmapheresis remain the treatments of choice.