Thrombocytopenia Caused By Passive Transfusion of Anti-Glycoprotein Ia/IIa Alloantibody (Anti-HPA-5b)

We describe a patient who developed transient and moderately severe thrombocytopenia (platelet count nadir 35 x 10(9)/L) after the transfusion of plasma. Using the technique of direct radioimmunoprecipitation, we showed that during the thrombocytopenia episode, the patient's platelets had IgG specifically bound to the glycoprotein (GP) Ia/IIa complex. Indirect radioimmunoprecipitation using serum from the plasma donor confirmed that anti-HPA-5b …