Anti-neutrophil cytoplasmic antibody associated vasculitis following rituximab: Outcomes of 50 patients in a tertiary single centre

Introduction: Antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) is an uncommon condition with heterogeneous multisystem organ involvement and significant morbidity and mortality. This study aimed to characterize the clinical features and laboratory characteristics, including B cell depletion, the ability to reduce corticosteroid dosage, and outcomes, of patients with AAV following rituximab treatment. Methods: Retrospective clinical and laboratory data were collected from patients with AAV who visited our lupus unit, including 50 treated with rituximab. Numeric response variables (median and range) were collected, including age, follow-up duration, disease duration, and Birmingham Vasculitis Activity Score (version 3). Statistical analyses were conducted using the SPSS 25.0 software. Statistical significance was considered a p-value <.05. Results: Of the 50 patients, 40 (80%) had granulomatosis with polyangiitis, 30 (75%) achieved remission, and 10 (25%) had active disease. Fifteen patients (30%) had positive ANCA levels at their last ANCA level assessment follow-up. Thirty-seven patients (74%) had B cell depletion, and 30 (81.1%) were in remission. Their median immunoglobulin levels were 7.6 (2.7–21.2) g/L for IgG, 0.5 (0.07–1.71) g/L for IgM, and 1.83 (0.14–4.87) g/L for IgA. Forty-two patients (84%) were able to lower their steroid dose to <7.5 mg, with 36 (85.7%) in remission and six (14.3%) having active disease ( p = .003). Conclusion: Our data suggests that most patients experience clinical remission after rituximab maintenance treatment. Half the patients were in remission, with normal creatinine levels and inflammatory markers. In addition, our patients could reduce steroid use.