High altitude (HA), with the main feature of hypobaric hypoxia, is an independent risk factor for thrombosis. However, little is known on the alterations of fibrinolytic system in adaptation to HA....

Background: ABO blood group is a hereditary factor of plasma levels of coagulation factor VIII (FVIII) and von Willebrand factor (VWF). Age and gender have been shown to influence FVIII, VWF, fibrinogen (Fbg), and ADAMTS13 (A disintegrin and metalloprotease with thrombospondin type 1 motif, 13). We investigated the effects of ABO type, age, and gender on plasma levels of FVIII, Fbg, VWF, and ADAMTS13 in a Chinese population.Methods: A total of 290 healthy volunteers were eligible for this study. ABO blood group was determined by indirect technique. FVIII:C and Fbg were measured by clotting assays. VWF antigen (VWF:Ag), collagen-binding activity (VWF:CBA), and ADAMTS13 antigen were assessed by ELISA, whereas VWF ristocetin cofactor activity (VWF:Rcof) was performed by agglutination of platelets with ristocetin.Results: Mean FVIII:C and VWF levels (VWF:Ag, VWF:CBA, and VWF:Rcof) were significantly higher in non-O than in O type subjects (p < 0.05 for all comparison). ADAMTS13 antigen decreased with increasing age, whereas the other parameters increased. Other than ADAMTS13 (p < 0.01), no gender-related variations were observed in the other parameters. Moreover, FVIII:C, Fbg, VWF:Ag, VWF:CBA, and VWF:Rcof showed significant and positive relationships with age (r = 0.421, 0.445, 0.410, 0.401, and 0.589, resp.; allp < 0.001), whereas a negative relationship was observed for ADAMTS13 antigen (r = 0.306;p = 0.006). Furthermore, FVIII:C were strongly correlated with VWF:Ag, VWF:CBA, and VWF:Rcof (r = 0.746,r = 0.746, andr = 0.576, resp.;p < 0.0001). VWF parameters were also strongly correlated with each other (r = 0.0.847 for VWF:Ag and VWF:CBA;r = 0.722 for VWF:Ag and VWF:Rcof;p < 0.0001).Conclusions: ABO blood group, age, and gender showed different effects on plasma levels of FVIII:C, Fbg, VWF:Ag, VWF:CBA, VWF:Rcof, and ADAMTS13 antigen. These new data on a Chinese population are quite helpful to compare with other ethnic groups.