Membranous nephropathy in the older adult: epidemiology, diagnosis and management.

Membranous nephropathy is the most important cause of the nephrotic syndrome in elderly patients (aged >65 years). The clinical presentation is similar in older and younger patients, although elderly patients more often present with renal failure. Notably, glomerular filtration rate (GFR) is usually lower in the elderly due to the physiological decline in GFR after the age of 30 years. Secondary causes, especially malignancies, are more common in older patients with membranous nephropathy. Therefore, elderly patients should undergo a thorough examination to exclude a secondary cause. The prognosis of elderly patients with idiopathic membranous nephropathy is not very different from that of younger patients. All elderly patients should receive symptomatic treatment aimed at reducing hypertension, oedema, proteinuria and hyperlipidaemia. It is recommended that elderly patients with a low serum albumin (<2 g/dL) receive prophylactic anticoagulation because of a high risk for thrombosis. Immunosuppressive therapy should be reserved for elderly patients at high risk of progression to end-stage renal disease because the elderly are particularly prone to the adverse effects and infectious complications of immunosuppressive therapy. High-risk elderly patients are characterised by renal insufficiency (GFR <45 mL/min/1.73m(2)), an increase in serum creatinine of >25% or a severe persistent nephrotic syndrome not responding to symptomatic treatment. In addition, elderly patients with a relatively normal GFR (>or=45 mL/min/1.73m(2)) and high urinary excretion of beta(2)-microglobulin and IgG are also at increased risk of developing end-stage renal disease; however, the deterioration in renal function is usually a slow process. Therefore, such patients benefit from immunosuppressive therapy only if their life expectancy is good. If immunosuppressive therapy is started, first-line treatment consists of prednisone and cyclophosphamide. If cyclophosphamide is contraindicated or fails to induce a remission, ciclosporin could be used. Treatment with ciclosporin should be limited to patients with a relatively normal renal function (GFR >60 mL/min/1.73m(2)) in view of its nephrotoxicity in patients with renal dysfunction.