ANTINEUTROPHIL CYTOPLASMIC ANTIBODIES IN WEGENERS GRANULOMATOSIS AND OTHER DISEASES - CLINICAL ISSUES

BACKGROUND An association between antineutrophil cytoplasmic antibodies (ANCA) and nonimmune complex-mediated glomerulonephritis was first reported over 10 years ago. In Wegener's granulomatosis, the antibody usually binds proteinase 3. Antibodies to a variety of other antigens have been identified in a broad range of diseases. SUMMARY The typical coarse, granular cytoplasmic ANCA pattern on indirect immunofluorescence almost always indicates reactivity with proteinase 3, whereas the perinuclear ANCA pattern may reflect reactivity with a host of different antigens. Antibodies to proteinase 3 are overwhelmingly associated with Wegener's granulomatosis (specificity greater-than-or-equal-to 90%). In a significant number of patients, however, disease activity is not linked to an ANCA titer. ANCA may play a role in the pathogenesis of many types of inflammatory conditions. Antibodies to proteinase 3 may be important in predisposing to Wegener's granulomatosis, but definitive in vivo proof of their role is not yet available.