Rituximab treatment in ANCA-associated vasculitis patients: outcomes of a real-life experience from an observational cohort.

Rituximab is a first-line therapy in patients with anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV). Among previous studies evaluating its efficacy, the Hispanic/Latino population has been underrepresented. This study aimed to assess the outcomes of AAV patients treated with rituximab in a tertiary care center in Mexico. This is a retrospective cohort study including patients with granulomatosis with polyangiitis (GPA), microscopic polyangiitis (MPA), or renal-limited vasculitis (RLV), who received at least one dose of rituximab (induction or maintenance therapy) from January 2014 to October 2020. Demographic, clinical, serological, histopathological, and treatment-related variables were retrieved. Outcomes were the rate of remission at 6 months during induction and the rate of relapses during maintenance. Damage, serious infections, and death were assessed. Differences between patients with and without remission were analyzed. Forty-two patients received rituximab, 34 of them as induction to remission. Twenty-two patients (65%) achieved remission after 6 months. Patients who achieved remission were younger than those who did not (50 vs. 60 years, p = 0.03). During induction, severe infections, most frequently pneumonia, occurred in 9 (26%), and one patient died. Twenty-four patients received rituximab as maintenance; of them, 23 (96%) achieved complete response, and 8 (33%) experienced relapses (median follow-up time 19 months). During maintenance, severe infections (pneumonia) occurred in 5 patients (21%), and 3 of them (13%) died. In this observational cohort study, the outcomes were similar to the ones reported in other populations, whereas severe infections were frequent and associated with mortality. Key Points • In this study, the outcomes of 42 Mexican patients with ANCA-associated vasculitis treated with rituximab were assessed in a real-life setting. • At 6 months, 65% of the patients achieved remission with rituximab, especially those younger than 50 years of age. • During maintenance therapy with rituximab, 96% of the patients achieved complete response, and 33% experienced relapses. • Severe infections, mostly pneumonia, occurred in 26% of patients during induction and 21% of patients during maintenance therapy with rituximab.