Membranous nephropathy (MN) is a unique glomerular lesion that is the most common
cause of idiopathic nephrotic syndrome in nondiabetic white adults. About 80% of cases are
renal limited (primary MN, PMN) and 20% are associated with other systemic diseases or
exposures (secondary MN). This review focuses only on PMN. Most cases of PMN have
circulating IgG4 autoantibody to the podocyte membrane antigen PLA2R (70%), biopsy
evidence PLA2R staining indicating recent immunologic disease activity despite negative …