PERINUCLEAR ANTINEUTROPHIL CYTOPLASMIC ANTIBODY IN RHEUMATOID-ARTHRITIS - A MARKER OF SEVERE DISEASE WITH ASSOCIATED NEPHROPATHY

Objective. To evaluate the clinical significance of antineutrophil cyt oplasmic antibodies (ANCA) in patients with rheumatoid arthritis (RA), and especially in those with clinically suspected or histologically p roven nephropathy. Methods. A total of 246 RA patients with (n = 149) and without (n = 97) histologically proven (n = 99) or clinically susp ected (n = 50) nephropathy were studied for the presence of ANCA by im munofluorescence and enzyme immunoassay. Results. Perinuclear ANCA (pA NCA) were found in 52 (21%) of the 246 patients. Patients with clinica lly suspected or histologically proven nephropathy were significantly more frequently positive for pANCA (30% versus 7%; P < 0.00005) and ha d significantly higher mean (+/-SD) pANCA log titers (103 +/- 5.6 vers us 27 +/- 3.0; P = 0.0011) than patients without clinically evident re nal disease, Positivity for pANCA was associated with clinical and lab oratory findings indicating severe basic disease and increased inflamm atory activity, Irrespective of this association, pANCA acted as a sig nificant and independent predictor of RA-associated nephropathy. Concl usion. Perinuclear ANCA in RA indicate severe disease with increased i nflammatory activity. There is an especially strong and independent as sociation between pANCA and RA-associated nephropathy.