Remission of C3 glomerulopathy with rituximab as only immunosuppressive therapy.

C3 glomerulopathy (C3GP) is a membranoproliferative glomerulonephritis without immunoglobulin deposits. Activation of the alternative pathway of the complement system is central in its pathogenesis. The presence of a C3 nephritic factor (C3Nef), or deficient factor H or I is associated with C3 GP. The treatment is not codified. Here we describe a case of a Caucasian male with a dense deposit disease (a form of C3GP) revealed by nephritic syndrome. C3Nef was present. We treated him with rituximab as the sole immunosuppressive regimen and obtained a complete remission on proteinuria. The effect was sustained at more than 2 years with only two courses of treatment and an excellent tolerance. Rituximab could be proposed as a treatment of C3GP associated with antibodies interfering with complement alternative pathway.