C3 and membranoproliferative glomerulonephritis: Membranoproliferative glomerulonephritis (MPGN), types I, II, and III, have been included in this entity.4, -6 The most common form of C3G is MPGN I with predominantly subendothelial deposits, followed by MPGN II, also known as dense deposit disease (DDD).3,7 Patients with DDD have circulating autoantibodies known as C3 nephritic factor.