Antineutrophil cytoplasmic autoantibodies (ANCA)--markers in diagnosis and monitoring systemic vasculitides.

We present a new class of autoantibodies--ANCA (antineutrophil cytoplasmic autoantibodies) which recognize as target antigen different enzyme constituents of primary granules of neutrophil granulocytes. These autoantibodies are present in a large number of diseases, such as: systemic vasculitides, idiopathic crescentic glomerulonephritis, inflammatory bowel diseases and in some other conditions, including rheumatoid arthritis, SLE, Felty syndrome, acute and chronic infections. ANCA not only facilitate the diagnosis but also have a pathophysiological role for some of the idiopathic vasculitides. In our study, including 110 patients referred to the laboratory for ANCA testing by indirect immunofluorescence technique, only 25 patients were positive with a diffuse cytoplasmic (c ANCA) or perinuclear (p-ANCA) pattern on alcohol fixed slides. Some relevant cases are presented in order to emphasize that ANCA antibodies are a useful marker in the early diagnosis of systemic vasculitides, allowing effective therapeutic handling.