Identification of risk factors for treatment resistance and relapse would be crucial to personalization therapy in patients with myeloperoxidase (MPO)-anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (MPO-AAV). Current evidence with regard to the risk factors for treatment resistance and relapse remains limited and inconclusive. We aimed to assess the predictors for treatment resistance and relapse in a single-center cohort of Chinese patients with MPO-AAV in this study. In total, 184 patients with MPO-AAV were included. Treatment resistance occurred in 64 (34.9%) of 184 patients and was positively associated with lung involvement (odds ratio [OR] 3.581, 95% CI 1.137-11.278, p = 0.029) and the initial serum creatinine level (OR 1.004, 95% CI 1.001-1.007, p = 0.010) and was negatively associated with platelet (OR 0.992, 95% CI 0.987-0.998, p = 0.007) and serum C3 levels (OR 0.998, 95% CI 0.996-0.999, p = 0.004). Relapse occurred in 29 (24.17%) of 120 patients in whom remission was achieved and was independently associated with lung involvement (hazard ratio [HR] 4.595, 95% CI 1.272-16.599, p = 0.020) and cardiovascular involvement (HR 3.689, 95% CI 1.237-11, p = 0.019,). The serum globulin was demonstrated to be negatively associated with relapse independently (HR 0.876; 95% CI 0.806-0.953; p = 0.002). This retrospective study of MPO-AAV patients in a single Chinese center suggests that treatment resistance was positively associated with lung involvement and the initial serum creatinine level and was negatively associated with platelet and serum C3 levels. Lung involvement and cardiovascular involvement were associated with an increased risk of relapse, while the higher serum globulin was demonstrated to be in association with a decreased risk of relapse.
Keywords: ANCA-associated vasculitis; Myeloperoxidase; Relapse; Risk factors; Treatment resistance.