Clinical Presentation - Post-Transfusion Purpura (PTP)

Signs, symptoms, and sequelae include:

• severe thrombocytopenia (< 10 x 109/L in 80% of cases)
• mucous membrane bleeding
• epistaxis
• GI hemorrhage
• urinary tract bleeding
• intracranial hemorrhage
• occasionally accompanied by fever, chills or bronchospasm

Mechanism

The mechanism of post transfusion purpura (PTP) is unclear but seems related to the platelet-specific alloantibody formed from prior transfusion/pregnancy and triggered in some way by the recent transfusion. Of the many hypotheses proposed to explain the syndrome, one is that autoantibody forms in conjunction with the platelet alloantibody and so that both transfused allogeneic and recipient autologous platelets are destroyed.