FCGR2A and autoimmune thrombocytopenic purpura: Autoantibodies against GPIbα or GPIIbIIIa in patients with immune thrombocytopenia (ITP) induce the secretion of endogenous neuraminidases from platelets, leading to Fc–FcγR-independent clearance of desialylated platelets in the liver [8, 13].