Efficacy and tolerability of rituximab with or without PEGylated interferon alfa-2b plus ribavirin in severe hepatitis C virus-related vasculitis: a long-term followup study of thirty-two patients.

OBJECTIVE: To report on the long-term followup of a cohort of patients with hepatitis C virus (HCV)-related vasculitis treated with rituximab with or without PEGylated interferon alfa-2b (PEG-IFN alfa-2b) plus ribavirin. METHODS: The study group comprised 32 HCV RNA-positive patients with HCV-related vasculitis: 20 patients were treated with rituximab and PEG-IFN alfa-2b (9 of whom had not previously received antiviral treatment and 11 of whom had experienced disease resistance to or relapse with antiviral treatment), and 12 antiviral-intolerant patients were treated with rituximab alone. RESULTS: Treatment with rituximab and PEG-IFN alfa-2b plus ribavirin induced a complete clinical response and a partial clinical response in 80% and 15% of patients, respectively, a complete immunologic response and a partial immunologic response in 67% and 33% of patients, respectively, and a sustained virologic response in 55% of patients. Treatment with rituximab alone induced a complete clinical response and a partial clinical response in 58% and 9% of patients, respectively, and a complete immunologic response and a partial immunologic response in 46% and 36% of patients, respectively. B cell depletion was achieved in 96% of patients, and B cell recovery began after a median delay of 12 months. After a mean+/-SD followup period of 23+/-12 months, 22% of patients experienced a clinical relapse, and 34% of patients experienced an immunologic relapse. All relapses were associated with the absence of virologic control, and 78% of relapses were associated with B cell recovery. Six patients were re-treated with rituximab. All 6 of these patients had a complete clinical response, 50% had a complete immunologic response, and 50% had a partial immunologic response. Rituximab was well tolerated overall. CONCLUSION: Rituximab is an effective treatment of severe and/or refractory HCV-related vasculitis. Relapses were consistently associated with the absence of virologic control. The clinical and immunologic efficacy of rituximab after repeated infusion appeared to be the same as that observed after induction therapy.