Prediction of relapses in Wegener's granulomatosis by measurement of antineutrophil cytoplasmic antibody levels: a prospective study.
OBJECTIVE
Prediction of relapses in Wegener's granulomatosis (WG) by measuring levels of antineutrophil cytoplasmic antibodies (ANCA) directed against proteinase 3 (PR3) or myeloperoxidase (MPO) remains a controversial issue. To assess the value of serial quantification of ANCA by indirect immunofluorescence (IIF) and antigen-specific enzyme-linked immunosorbent assay (ELISA) for monitoring disease activity in patients with WG, a prospective observational study was conducted in patients with WG attending an outpatient clinic in the Netherlands.


METHODS
One hundred patients with WG (85 with PR3-ANCA, 15 with MPO-ANCA) were studied prospectively from 1996 to 1998. Serum samples were obtained and analyzed every 2 months for ANCA levels. Disease activity was prospectively assessed without knowledge of the ANCA levels.


RESULTS
Relapses occurred in 37 of 100 patients (37%). Thirty-four (92%) of the 37 patients showed a rise in the level of ANCA preceding their relapse, as detected by ELISA or IIF. The predictive value of an increase in ANCA titers for relapse was 57% (17 of 30) for cytoplasmic/classic ANCA (cANCA; by IIF), 71% (27 of 38) for PR3-ANCA (by ELISA), and 100% (3 of 3) for MPO-ANCA (by ELISA). The predictive value of a rise in ANCA as measured by ELISA or IIF did not substantially improve following concomitant measurement of the IgG3 subclass of PR3-ANCA. Forty-three percent of patients who showed a rise in cANCA (by IIF) and 29% with a rise in PR3-ANCA (by ELISA) did not subsequently experience a relapse.


CONCLUSIONS
Serial measurement of ANCA levels is valuable for the early prediction of relapses in patients with WG.
Boomsma
M M
MM
University Hospital Groningen, The Netherlands.
Stegeman
C A
CA
van der Leij
M J
MJ
Oost
W
W
Hermans
J
J
Kallenberg
C G
CG
Limburg
P C
PC
Tervaert
J W
JW
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019268:Antibodies, Antineutrophil Cytoplasmic / Q000097:blood* / Q000276:immunology; D000918:Antibody Specificity; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005500:Follow-Up Studies; D014890:Granulomatosis with Polyangiitis / Q000276:immunology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009195:Peroxidase / Q000276:immunology; D012372:ROC Curve; D012008:Recurrence
D019268:Antibodies, Antineutrophil Cytoplasmic; D009195:Peroxidase