Successful induction of remission with rituximab for relapse of ANCA-associated vasculitis post-kidney transplant: report of two cases.

Kidney transplantation should be considered the treatment of choice for patients with end-stage renal disease due to antineutrophil cytoplasmic antibody (ANCA) associated vasculitis (AAV). However, relapses of AAV have been reported to occur in 9-40% of cases following kidney transplantation and may adversely affect allograft outcome. These relapses are usually treated with cyclophosphamide (CYC) and glucocorticoids, but the repeated use of CYC carries a risk of substantial toxicity that may limit or prohibit its use in some patients. B lymphocytes have been implicated in the pathogenesis of AAV, and their depletion has been effective as salvage therapy for refractory disease in the nontransplant setting. We report the successful induction of remission using rituximab in two patients who suffered relapse of AAV post-kidney transplant. Given the substantial morbidity and adverse effects of CYC, rituximab appears to be a suitable alternative agent to treat relapses of AAV posttransplantation.