The role of antineutrophil cytoplasm antibodies, anticardiolipin antibodies, von Willebrand factor antigen, and fibronectin for the diagnosis of systemic vasculitis.

Autoantibodies directed against cytoplasmic components of neutrophil granulocytes and monocytes (c-ANCA) are a disease specific marker for Wegner's granulomatosis (WG). Autoantibodies against cardiolipin (aCl) are specific for a subgroup of autoimmune disorders, which can also be associated with systemic vasculitis. Fibronectin (Fn) and von Willebrand factor antigen (vWfAg) are produced by blood vessel endothelial cells in response to injury. We tested sera of 61 patients with various types of systemic vasculitides, sera of 13 patients with retinal vasculitis, and sera of 199 patients with rheumatic diseases for c-ANCA, aCl, Fn, and vWfAg. c-ANCA was positive in 14/17 patients with WG, and 2/4 with polyarteritis nodosa (PAN). No serum from healthy donors or patients with other vasculitic or rheumatic diseases was positive for c-ANCA. Moreover, we found aCl, Fn, and vWfAg significantly elevated in almost all patients with vasculitic syndromes. Therefore, we consider c-ANCA a marker, specific for the diagnosis of WG or PAN, whereas aCl, Fn, and vWfAg are nonspecific but sensitive markers of vascular damage.