Summary

• A chronic immunologically mediated disease of the glomerular basement membrane that may resolve spontaneously, persist with stable renal function, or progress to end-stage renal failure. One of the most common causes of nephrotic syndrome in adults.
• A diagnosis of idiopathic membranous nephropathy should only be made after secondary causes have been excluded. A renal biopsy is required for definitive diagnosis.
• Approach to treatment is based on risk (low, medium, or high) of progression of renal disease.
• Treatment in low-risk patients is largely conservative, including a low-sodium and low-protein diet and statins for hyperlipidaemia. Hypertension is treated with ACE inhibitors or angiotensin II receptor antagonists, and oedema can be managed with the use of diuretics.
• Medium- and high-risk patients may be treated with a combination of corticosteroids with either cytotoxic agents or ciclosporin.