Platelet Aggregation by a Specific Human Immunoglobulin Preparation

Abstract

SummaryA patient with severe chronic thrombocytopenic purpura is described, whose serum, after repeated transfusions of platelet-rich plasma, of her ABO blood group, was found to contain immunoglobulin G, which produced clumping in platelet-rich plasma from 15 volunteers out of 20. Direct and indirect evidence was obtained that clumping was due to release of endogenous platelet-ADP. In addition, a direct effect of the immunoglobulin preparation on the platelet membrane could be demonstrated.