Abstract
Objective. The diagnostic values of antiproteinase 3 and antimyeloperoxidase tests using antineutrophil cytoplasmic antibodies (ANCA) are well established. Our study determined whether an increase in ANCA level was a predictor of disease flareup.
Methods. Our study included 126 patients with ANCA-associated renal vasculitis treated at 9 nephrology centers in Japan. The relationship between increased ANCA levels and relapse was assessed using time-dependent multivariate Cox regression models adjusted for clinically relevant factors. The outcome of interest was the time from remission to first relapse.
Results. During the observation period [median 41 mos, interquartile range (IQR) 23–66 mos], 118 patients (95.8%) achieved remission at least once. After achieving remission, 34 patients relapsed (21.7%). Time-dependent multivariate Cox regression models revealed that lung involvement (adjusted HR 2.29, 95% CI 1.13–4.65, p = 0.022) and increased ANCA levels (adjusted HR 17.4, 95% CI 8.42–36.0, p < 0.001) were significantly associated with relapse. The median time from ANCA level increase to relapse was 0.6 months (IQR 0–2.1 mos).
Conclusion. In our study, an increase in ANCA level during remission was associated with a risk of disease relapse. A rise in ANCA level may be useful for guiding treatment decisions in appropriate subsets of patients with ANCA-associated vasculitis.
- ANTINEUTROPHIL CYTOPLASMIC ANTIBODIES
- ANCA-ASSOCIATED VASCULITIS
- GRANULOMATOSIS WITH POLYANGIITIS
- MICROSCOPIC POLYANGIITIS
- ANCA LEVEL
- RELAPSE
Footnotes
Supported in part by a Grant-in-Aid for Progressive Renal Diseases Research, Research on Rare and Intractable Disease, from the Ministry of Health, Labor, and Welfare of Japan.
- Accepted for publication June 15, 2015.