Polymorphisms of the human platelet antigens HPA-1, HPA-2, HPA-3, and HPA-5 on the platelet receptors for fibrinogen (GPIIb/IIIa), von Willebrand factor (GPIb/IX), and collagen (GPIa/IIa) are not correlated with an increased risk for stroke

Background and purpose A recent study has described a high incidence of the human platelet antigen (HPA)-1b alloantigen in patients with myocardial infarction. We investigated the distribution of gene polymorphisms of platelet glycoproteins (GPs) in patients with cerebrovascular disease (CVD) and stroke. The polymorphic systems we have studied are HPA-1 and HPA-3 on the fibrinogen receptor (GPIIb/IIIa), HPA-2 on the von Willebrand factor receptor (GPIb/IX), and HPA-5 on one of the platelet collagen receptors (GPIa/IIa). Methods DNA was isolated from peripheral blood collected from 218 consecutive stroke patients; 165 neurological inpatients without signs of CVD, and 321 healthy blued donors. The genotypes of HPA-1, HPA-2, HPA-3, and HPA-5 were determined by sequence specific primer polymerase chain reactions. Results The calculated allele frequencies were as follows: for CVD patients, HPA-1a/b 0.81/0.19, HPA-2a/b 0.91/0.09, HPA-3a/b 0.61/0.39, and HPA-5a/b 0.92/0.08; for inpatients, HPA-1a/b 0.83/0.17, HPA-2a/b 0.91/0.09, HPA-3a/b 0.62/0.38, and HPA-5a/b 0.93/0.07; and for blood donors, HPA-1a/b O.85/0.15, HPA-2a/b 0.94/0.06, HPA-3a/b 0.60/0.40, and HPA- 5a/b 0.92/0.08. There were no statistically significant differences for the analyzed HPA polymorphism frequencies either between the CVD patients and the non-CVD inpatients or the CVD patients and blood donors. However, the HPA-1b genotype was slightly more frequent in patients (CVD and non-CVD) than in the healthy blood donors. Conclusions Our results indicate that the HPA-1, HPA-2, HPA-3, and HPA-5 polymorphisms are not associated with an increased risk for stroke.