Sudden Development of Thrombocytopenia After Reversal of Anticoagulation for Surgery

Abstract

Herein, we report a case of post-transfusion purpura after the reversal of anticoagulation for surgical purposes in a 66-year old ethnic Asian man who was undergoing long-term warfarin therapy for antiphospholipid syndrome. The patient experienced a sudden decrease in platelet count, from 308,000 per μL from the day of admission to 38,000 per μL the following day. Follow-up testing revealed unremarkable red blood cell (RBC) morphology, no evidence of platelet clumping, and negative heparin-induced antibody test results. Platelet antibody testing revealed anti-HPA15a antibodies.

Posttransfusion purpura with antibodies against human platelet antigen‐4a following checkpoint inhibitor therapy: a case report and review of the literature

“…The perplexing feature of this condition is that even though the implicated mechanism is an alloantibody, there is destruction of the patient's own PLTs leading to severe thrombocytopenia. The pathophysiology behind PTP is still unclear, but several mechanisms have been proposed . One hypothesis involves the formation of immune complexes that lead to destruction of autologous PLTs, an innocent bystander model.…”

“…The vast majority of the reported PTP cases involve antibodies directed against HPA‐1a . However, there have been case reports of PTP associated with alloantibodies against the other biallelic HPAs as listed in Table . Of those cases, the most frequent alloantibodies are directed against HPA‐1b and HPA‐3a.…”

<p>Post-Transfusion Purpura: Current Perspectives</p>

“…Individuals with HPA-1b/1b genotype previously immunized via pregnancy or transfusion are the prototypical subjects of most case reports. Cases in men, albeit rare, have also been reported 3,8–10. Alloantibodies against a common HPA antigen found on the majority of normal donor platelets are thought to be somehow responsible for destruction of platelets of the transfusion recipient even though they lack the alloantigen toward which antibody is directed.…”