INCIDENCE, TARGET ANTIGENS, AND CLINICAL IMPLICATIONS OF ANTINEUTROPHIL CYTOPLASMIC ANTIBODIES IN RHEUMATOID-ARTHRITIS

Objective. To determine the incidence of antineutrophil cytoplasmic an tibodies (ANCA) in rheumatoid arthritis (RA), to detect the target ant igens of ANCA, and to compare clinical and laboratory data of ANCA+ wi th ANCA- patients with RA. Methods. 385 sera of patients with RA were screened for ANCA by indirect immunofluorescence. ANCA+ sera were furt her analyzed for target antigens by ELISA. The ANCA+ patients were com pared to randomly selected ANCA- patients with RA with respect to ser ological and radiological variables and extraarticular involvement. Re sults. ANCA were found in 16% of patients with RA (61/385 sera). All s era showed a perinuclear (pANCA) pattern. Antibodies directed against 5 different target antigens were found in 18/61 pANCA+ sera, antibodie s directed against proteinase 3 were not observed. The analysis of ANC A+ and ANCA- patients revealed that the pANCA+ group exhibited signifi cantly higher serological markers of inflammation (p < 0.005) and a hi gher incidence of rheumatoid factor (p < 0.005). Furthermore, vasculit ic involvement was found at a higher frequency (p < 0.05) in the pANCA + group. Five patients in the pANCA+ group had pulmonary involvement, but none in the pANCA- group. Conclusion. pANCA in RA may be a marker for a more aggressive course of disease in respect to serological vari ables and extraarticular manifestations including rheumatoid vasculiti s and lung involvement.