Membranous Nephropathy
Overview
Plain-Language Overview
Membranous Nephropathy is a kidney condition that affects the tiny filtering units called glomeruli. It causes the filters to become thickened and damaged, which can lead to protein leaking into the urine. This protein loss can cause swelling in the body, especially in the legs and around the eyes. The condition mainly affects the kidneys' ability to clean the blood properly. It can develop slowly and may cause symptoms like fatigue and foamy urine. Over time, it can lead to more serious kidney problems if untreated.
Clinical Definition
Membranous Nephropathy is a primary glomerular disease characterized by subepithelial immune complex deposition along the glomerular basement membrane, leading to its thickening. It is most commonly caused by autoantibodies against the phospholipase A2 receptor (PLA2R) on podocytes, resulting in complement activation and podocyte injury. This disease is a leading cause of nephrotic syndrome in adults, presenting with heavy proteinuria, hypoalbuminemia, edema, and hyperlipidemia. Secondary causes include infections, malignancies, drugs, and autoimmune diseases. The hallmark histopathologic finding is diffuse capillary wall thickening without significant cellular proliferation. The clinical course varies from spontaneous remission to progression to chronic kidney disease.