Platelet glycoprotein IIIa polymorphism HPA 1b (PlA2):: no association with platelet fibrinogen binding

The role of the platelet glycoprotein (GP) IIIa polymorphism HPA 1b (Pl(A2)) in the risk of arterial thrombosis is controversial. Mie investigated the effect of the Ib allele on platelet fibrinogen binding by flow cytometry. Samples from 35 healthy platelet and plasma donors possessing the Ib allele were compared with 35 1a/1a donors. We found no allele-dependent difference in percentage of platelets binding fibrinogen (P = 0.6), nor in mean cell fluorescence (P = 0.3) following stimulation with ADP. These results render it unlikely that any relationship between the Ib polymorphism and arterial thrombosis is mediated by a significant effect on fibrinogen binding.