Membranoproliferativeglomerulonephritis (MPGN) is a pattern of glomerular injury. MPGN is characterized by mesangial expansion and hypercellularity, endocapillary hypercellularity, and double contour formation along the capillary walls. MPGN can result from 2 main causes: 1) deposition of Ig/immune-complexes (IC) and 2) deposition of complement factors. Based on the etiology of MPGN, Drs. Sethi and Fervenza proposed a new histologic classification of MPGN into Ig/IC-mediated MPGN and complement-mediated MPGN. In this recording, Dr. Sethi demonstrates the use of the new classification with case studies. A presentation by Sanjeev Sethi, MD, PhD.