[The von Willebrand factor antigen in systemic vasculitis].

ELISA was used to investigate concentrations of Willebrand's factor antigen (WF III Ag) in 131 patients with various forms of systemic vasculitis (SV) and 93 patients with cardiovascular diseases. Compared to donors, a mean WF III Ag level proved significantly higher in all nosological variants of SV except periarteritis nodosa. Skin livedo vasculitis did not produce noticeable deviations in WF III Ag levels versus those in donors, whereas atherosclerosis obliterans showed these levels to be significantly elevated.