[Kidney involvement in mixed cryoglobulinemia: which treatment?]

A kidney involvement is found in 20 to 56% of patients presenting with a cryoglobulinemic vasculitis, type II IgMk, associated to hepatitis C virus infection (HCV). Patients present with a membrano-proliferative glomerulonephritis. In HCV-associated cases, treatment guidelines are adapted to the severity of the disease. In severe forms, including those with kidney involvement, treatment starts with rituximab then an optimal antiviral combination. In non-HCV cases combination with steroids, immunosuppressants and plasmapheresis showed variable efficacy. Retrospective analysis of rituximab showed a great efficacy in more than 80% patients with an increased risk of severe infections (14.1/100 patient-years), particularly in patients over 70 years, with a renal insufficiency and previously treated with high dose steroids.