Membranous nephropathy

Primary membranous nephropathy is the most common form of nephrotic syndrome in Caucasian adults and a frequent cause of end-stage renal disease. It is characterized by sub-epithelial immune deposits and is the prototype of an autoimmune glomerular disease. Clinical course is variable and up to 30 % of patients may go into spontaneous remission. The discovery of two major podocytes antigens: neutral endopeptidase (NEP), involved in rare cases of neonatal MN, and the M-type phospholipase-A₂ receptor 1 (PLA₂R1) the first antigen discovered in adults, have been major breakthroughs in our understanding of the pathogenesis of human MN. The presence of circulating antibodies against bovine serum album in some children with membranous nephropathy raises the possibility that food antigens may also be involved in its pathogenesis. Genetic susceptibility studies have linked single-nucleotide polymorphisms (SNPs) in the genes encoding M-type phospholipase A₂ receptor 1 (PLA₂R) and HLA complex class II HLA-DQ alpha chain 1 (HLA-DQA1) in Caucasian populations with membranous nephropathy. Current therapies include combined use of corticosteroids and alkylating agents, or calcineurin inhibitors. The first treatment may favor remission and protect renal function but may be associated with significant adverse effects. Calcineurin inhibitors may reduce proteinuria but have a high relapse rate. New therapies have being sought with the use of adrenocorticotropic hormone and rituximab. Further research may facilitate a more patient-specific treatment approach in these patients.