What is membraneous nephropathy?

➢ Characterized by subepithelial immunoglobulin-containing deposits along the GBM. ➢ Early in the disease, the glomeruli may appear normal by light microscopy, ➢ Well-developed cases show diffuse thickening of the capillary wall. ➢ Adults between 30 and 60 years; follows an indolent and slowly progressive course. ➢ Up to 80% of cases of MN are primary, caused by AB against podocyte antigens. ➢Pathogenesis : Membranous nephropathy is a form of chronic immune complex GN induced by AB reacting in situ to endogenous or planted glomerular antigens. AB against the podocyte antigen phospholipase A2 receptor (PLA2R) are frequently present. ➢Formation of subepithelial immune deposits leads to complement activation on the surface of podocytes and generates the membrane attack complex (C5-C9). This in turn causes podocyte injury and proteinuria