Long-term follow-up of different refractory systemic vasculitides treated with rituximab

There is increasing interest in rituximab (RTX) as an alternative to cyclophosphamide (CYC) for remission induction in systemic vasculitis. Recent studies have reported high remission rates, but it is not clear how long the initial remission lasts [1, 2]. A retrospective study was undertaken of 15 cases of refractory systemic vasculitis (11 Wegener's granulomatosis, 1 Churg-Strauss syndrome, 1 cutaneous polyarteritis nodosa and 2 cryoglobulinaemic vasculitis) treated with RTX, with a mean follow-up of 34 months. All had previously received CYC, and 14, at least one other immunosuppressive drug. All had active disease when treated (median Birmingham Vasculitis Activity Score (BVAS) 2003, 13). All cases achieved remission (BVAS 2003, 0). Thirteen required re-treatment, nine due to relapse (mean, 9 months after initial treatment) and four because of repopulation or rising ANCA in the context of CYC intolerance or previous CYC refractory disease. Relapsing cases have been successfully re-treated up to five further cycles, either at B cell repopulation or at six monthly intervals. Infections were rare. Mean IgG levels fell significantly, and IgM levels became subnormal in six cases. There were three cases of neutropenia, one severe at 10 months post-treatment. These results provide further evidence that RTX is an effective induction agent in systemic vasculitis. The optimal and long-term outcome of re-treatment remains to be defined.