Membranous nephropathy is the most common cause of nephrotic syndrome in adults. Binding of circulating autoantibodies to the glomerular filtration barrier leads to the development of this autoimmune disease. The clinical symptoms range from small proteinuria to severe nephrotic syndrome with enormous oedema, not controllable hyperlipidaemia and increased disposition for infection. One third of patients reach complete or partial remission of proteinuria under symptomatic treatment, which includes ACE-inhibitors and AT-I-blockers, loop diuretics and statins. Untreated the disease leads to loss of renal function over 5-10 years in 20-30% of patients. A risk score based on proteinuria and renal function is used to guide the decision when to start with an immunosuppressive therapy. A better adapted diagnostic and therapy of membranous nephropathy may be possible through measurement of circulating autoantibodies directed against a podocytic phospholipase-A(2) receptor.
