Recent advances and prognosis in idiopathic membranous nephropathy.

Idiopathic membranous nephropathy (MN) is one of the most common causes of nephrotic syndrome. Recently, progress has been made in understanding the pathogenesis of idiopathic MN with the finding of M-type phospholipase A2 receptor (PLA2R) antibodies in the serum and immune complexes of glomeruli in the majority of adult idiopathic MN patients. In the future, the detection of M-type PLA2R antibodies may help distinguish patients with primary MN who require aggressive immunosuppressive therapy from those with secondary disease. Levels of circulating antibody to this receptor may help in monitoring disease activity and in gauging response to therapy, as changes in antibody levels may precede changes in proteinuria. The degree of renal dysfunction or change in renal function over time and the level of persistent proteinuria are key prognostic factors in the decision to initiate therapy in idiopathic MN patients. Although spontaneous remissions occur in ~30% of patients, partial and complete remissions help to define the clinical course of an individual patient.