Platelet-Derived Microparticles May Influence Phenotypic Heterogeneity in Patients with Severe Hemophilia

Large heterogeneity in bleeding phenotype is observed among patients with severe hemophilia A. Some severe patients do not require regular replacement therapy, so to address the factors influencing phenotypic Heterogeneity in Patients with Severe Hemophilia A seems particularly important. We first initiate a cohort study 0f 274 patients with severe hemophilia A who were treated at the hemophilia treatment centre at Nanfang hospital, then 209 patients were enrolled and their bleedings were recorded, finally 12.9% (12/209) of the patients were found to be mild phenotypes, which annual bleeding rate(ABR)were less than 6 times. We then use Flow-cytometric analysis to detect the platelet-derived microparticles (PMPs) among patients with mild phenotypes, patients with severe phenotypes (ABR more than 24) and the normal control group, megamix beads (0.5μm; BioCytex, Marseille, France), CD42a-PE, CD42b-PE, CD41b-PE (GPIX, platelet MPs [PMPs], BD, NJ, USA) were involved, then the results showed that there was no difference in the level of PMPs between hemophliac patients and the normal control group (P=0.317), however, the level of PMPs in patients with mild phenotypes were significantly higher than patients with severe phenotypes (3.65±1.38 vs 1.13±0.64, P<0.05).These findings indicated that 12.9% were mild phenotypes in 209 patients with severe hemophilia A, moreover, the platelet-derived microparticles which may influence phenotypic heterogeneity in patients with severe haemophilia A will be further study for individual treatment.