Increased risk of thrombosis in FcγRIIA 131RR patients with HIT due to defective control of platelet activation by plasma IgG2

Thrombosis results in heparin-induced thrombocytopenia (HIT) from cellular activation involving Fc receptors. In this study, the FcγRIIA 131RR genotype was found to increase the risk of thrombosis in HIT patients (odds ratio: 5.9; 95% confidence interval: 1.7-20). When platelet aggregation tests (