title: Quantitative and qualitative assessment of plasma von Willebrand factor variations, as induced by forearm venous stasis in patients with diabetic microangiopathy.
abstract: Plasma von Willebrand factor was studied for quantitative and qualitative assessment in basal conditions and after release from the endothelium, as elicited by venous stasis of the forearm, in 8 healthy subjects and 8 patients with diabetic microangiopathy. von Willebrand factor was measured as factor VIII-related antigen (VIII R:Ag) and ristocetin co-factor (VIII R:Co). Its molecular size distribution was evaluated by bidimensional immunoelectrophoresis. The patients had higher basal levels of VIII R:Ag (171 +/- 45% vs 64 +/- 11% of plasma pooled from 20 healthy donors, p less than 0.05) and VIII R:Co (144 +/- 11% vs 88 +/- 8%, p less than 0.01). After stasis, both moieties increased significantly in the 2 groups, remaining higher in the patients (VIII R:Ag = 292 +/- 74% vs 89 +/- 18%, p = 0.01; VIII R:Co = 216 +/- 25% vs 116 +/- 10%, p less than 0.01). No differences in the molecular size distribution were observed between patients and controls, nor within the 2 groups before and after stasis. It is concluded that, in diabetic microangiopathy, the endothelial cells synthesize and store increased amounts of structurally normal von Willebrand factor.
mesh_terms: D000368:Aged; D000941:Antigens / Q000032:analysis; D001779:Blood Coagulation Factors / Q000032:analysis*; D003925:Diabetic Angiopathies / Q000097:blood*; D005169:Factor VIII / Q000032:analysis / Q000276:immunology; D005260:Female; D005542:Forearm / Q000098:blood supply*; D006801:Humans; D008297:Male; D008875:Middle Aged; D014841:von Willebrand Factor / Q000032:analysis*
chemical_list: D000941:Antigens; D001779:Blood Coagulation Factors; D014841:von Willebrand Factor; D005169:Factor VIII