Anti-neutrophil cytoplasmic antibody patterns can predict clinical relapse in ANCA-associated vasculitis: overall population and subgroups.

Abstract

In anti-neutrophil cytoplasmic antibody-associated vasculitis (AAV), relapses are cause of concern as they are unpredictable and predictors of poor prognosis. We aimed to assess the characteristic and predictors of clinical relapse in AAV. This retrospective study included 132 cases of AAV newly diagnosed from January 2016 through November 2021 in the Affiliated Hospital of Qingdao University. We reviewed clinical data of patients and analysed the risk factors for clinical relapse of overall population and subgroups by univariate and multivariate regression models and the K-M survival curve was plotted. The rate of relapse was highest in the positive conversion group than the others significantly (p<0.001). In overall population, ANCA patterns (p<0.001; persistent positive pattern: HR=3.352, 95%CI 1.463~7.678, p=0.004; positive conversion pattern: HR=4.760, 95%CI 2.094~10.820, p<0.001) and infections (HR =4.684, 95%CI 1.980~11.079, p<0.001) were significantly associated with clinical relapse. In myeloperoxidase (MPO)-AAV patients, ANCA patterns (p=0.001; persistent positive pattern: HR=4.495, 95%CI 1.508~13.396, p=0.007; positive conversion pattern: HR=7.404, 95%CI 2.652~20.671, p<0.001) and infections (HR=3.594, 95%CI 1.511~8.547, p=0.004) were significantly associated with clinical relapse. In renal involvement patients, ANCA patterns (p=0.004; persistent positive pattern: HR=3.618, 95%CI 1.364~9.592, p=0.01; positive conversion pattern: HR=4.492, 95%CI 1.778~11.352, p<0.001) and infections (HR=7.791, 95%CI 2.511~24.174, p<0.001) were significantly associated with clinical relapse, but were not in patients without renal involvement. Persistently positive and re-positive ANCA and infections predict clinical relapse in AAV, especially in patients with MPO-AAV and renal involvement. Regular ANCA monitoring should be carried out in high-risk populations.