Rituximab treatment for Glomerulonephritis in HCV-associated Mixed Cryoglobulinemia: efficacy and safety in the lack of steroids

OBJECTIVE: Rituximab, an anti-CD20 monoclonal antibody, has been used in lupus nephritis and membranous idiopathic nephropathy and has proved effective in non-renal manifestations of type II mixed cryoglobulinaemia (MC) syndrome. We investigated the possible efficacy and safety of rituximab in the treatment of cryoglobulinaemic nephritis. METHODS: Five patients with active, biopsy-proven, glomerulonephritis in hepatitis C virus (HCV)-related type II MC syndrome were treated with four weekly infusions of rituximab (375 mg/m2) in monotherapy, without steroids whenever possible. Rituximab was the first-line therapy in three cases. RESULTS: A rapid and sustained renal response was observed in all patients, in one of them without retreatment up to the last follow-up (month 21+). Renal biopsy was repeated after 6 months in one patient and histopathological improvement was documented. Three patients relapsed, at months +5, +7 and +12 of follow-up, respectively. Two of them were then retreated with rituximab and again presented a rapid improvement in renal function. Maintenance therapy with rituximab was performed in two patients: nephritis remission was maintained in both. Fc-gamma receptor 3a (FcgammaRIIIa) genotype characterization was consistent with the clinical response observed. Rituximab also proved effective against other active MC manifestations, when present. No major side-effects occurred and steroids were not required in the follow-up. CONCLUSIONS: Rituximab may provide effective and safe therapy in type II MC-related glomerulonephritis, possibly as first-line therapy, avoiding steroids and hazardous immunosuppressive treatment.