[Anti-cytoplasmic antibodies of polynucle or "ANCA". A new class of autoantibodies].

The specific antigens to antineutrophil cytoplasmic antibodies (ANCA) and their relations with renal diseases begin to be well-known. In patients with systemic vasculitis, two major antigens have been recognized: proteinase 3 and myoloperoxydase. These enzymes are located in the azurophilic granules of neutrophils and migrate to the surface of these cells when they are activated. Other antigens, such as elastase, lactoferrin, CAP57 and cathepsin G, have been identified, but they are less commonly encountered. The presence of ANCA is particularly frequent in Wegener's granulomatosis, microscopic periarteritis, crescentic necrotizing glomerulonephrites without immunoglobulin deposits; it is less frequent in periarteritis nodosa and in Churg-Strauss' syndrome. ANCA can now be considered as markers of vasculitis; they are related to disease activity and can be used to evaluate the effectiveness of treatments.