C3 and membranoproliferative glomerulonephritis: Other diagnoses were ruled out in this patient: monoclonal immunoglobulin deposition disease (there were no deposits of Kappa or lambda chains), membranoproliferative glomerulonephritis (absence of C3 deposits), amyloidosis (abscense of amyloid), fibrillary and immunotactoid glomerulonephritis (absence of deposits of IgG or C3).