Membranoproliferative glomerulonephritis, adult

Membranoproliferative glomerulonephritis (MPGN) is a pattern of glomerular injury seen in varied disease conditions, and in itself does not refer to a specific disease entity. Previously it was classified according to the ultrastructural location of deposits as MPGN type I, II or III. Since then, we have moved onto a classification based on etiology and pathogenesis. The two broad pathogenetic pathways include either glomerular injury secondary to an immune complex/ monoclonal immunoglobulin deposition or consequent to complement deposition in the setting of dysregulated abnormalities of the complement system. Appropriate classification based on immunofluorescence permits a detailed and tailored evaluation for underlying infections, autoimmune diseases, monoclonal gammopathy and/or abnormalities of the complement system. Recent use of ancillary diagnostic techniques such as pronase immunflourescence and mass spectrometry promote accurate diagnosis in challenging cases.