OBJECTIVE: Adult-onset IgA vasculitis (Henoch-Schönlein) (IgAV) is a rare systemic vasculitis characterized by IgA1-dominant deposits. The treatment of adult-onset IgAV is controversial and is based on the combination of glucocorticoids and immunosuppressive agents, but many patients have refractory or relapsing disease despite treatment. Rituximab (RTX) is a B cell-depleting antibody of proven efficacy in antineutrophil cytoplasmic antibody-associated vasculitis. We undertook this study to test the efficacy and safety of RTX in a multicenter cohort of patients with adult-onset IgAV. METHODS: In this multicenter observational study, we included patients with adult-onset IgAV who had received RTX either for refractory/relapsing disease or because they had contraindications to conventional glucocorticoid/immunosuppressive therapy. We analyzed the rates of remission (defined on the basis of the Birmingham Vasculitis Activity Score [BVAS]) and relapse as well as the variations over time in estimated glomerular filtration rate (GFR), proteinuria, C-reactive protein (CRP) level, BVAS, and prednisone dose. RESULTS: Twenty-two patients were included; their median duration of follow-up was 24 months (interquartile range 18-48 months). Sixteen patients received RTX as add-on therapy and 6 as monotherapy. Twenty patients (90.9%) achieved remission, and 7 of those 20 patients (35%) had subsequent relapse of disease. There were significant reductions in 24-hour proteinuria (P < 0.0001), CRP level (P = 0.0005), BVAS (P < 0.0001), and prednisone dose (P < 0.0001) from RTX initiation through the last follow-up visit; estimated GFR remained stable. RTX was generally well tolerated. One patient died after 60 months of follow-up. CONCLUSION: Our data suggest that RTX is an effective and safe therapeutic option for adult-onset IgAV.