[Antineutrophil cytoplasmic antibodies in nonvasculitis diseases: clinical correlates and target antigens].

The value of antineutrophil cytoplasmic antibodies (ANCA) in the diagnosis of several types of idiopathic vasculitis has been well-documented: In these diseases the ANCA show two classical immunofluorescence patterns, C-ANCA and P-ANCA, which have antigen specificity for the myeloperoxidase and proteinase 3, respectively. However, the appearance of ANCA in very different diseases other than the mentioned vasculitis, has been documented in recent years. In these diseases, the ANCA generally have atypical immunofluorescence patterns and are directed against neutrophil antigens that are different from the previous two, their clinical value still being under debate.