Glomérulopathie extramembraneuse

Extra-membranous nephropathy is characterised by immune complex deposits on the external side of the basement membrane. Activation of complement and oxidation pathways lead to basement membrane lesions. The most frequent form is idiopathic. At 5 and 10 years, renal survival is respectively around 90 and 65 %. A prognostic model can be based on the level and duration of proteinuria and the rate of progression of renal insufficiency on several months. Excretion of C5b-9, β2 microglobulin and IgG are strong predictors of outcome. Symptomatic treatment is based on anticoagulation if the patient has a nephrotic syndrome, conversion enzyme inhibitor, angiotensin II antagonist, statins, antioxidant and pentoxyfilline. Immunosuppressors are discussed for patients with bad prognostic factors. Corticosteroids alone are not indicated. Treatment must include corticosteroids and an alkylant agent for a minimal duration of 6 months. This treatment lessens proteinuria but evidence is still lacking about long term renal prognosis. Some patients with renal failure at the initiation of treatment experience slowered progression of renal failure. Cyclosporine also allows an improvement of proteinuria but there is no definite evidence for an improvement in long-term renal prognosis.