[Idiopathic nephrosis (minimal glomerular lesions, segmental and focal hyalinosis)]

Idiopathic nephrosis, the most common cause of nephrotic syndrome, is histologically defined by minimal glomerular changes, diffuse mesangial proliferation or focal and segmental glomerulosclerosis. The response to corticosteroids carries greater prognostic weight than the histological features seen on the initial renal biopsy. The severity of the condition lies in the risk of relapses which occurs in more than half of cases when steroid dosage is decreased (steroid dependency), then requiring, in case of steroid toxicity, the use of alkylating agents or, more recently, cyclosporine. In 10% of the cases, nephrosis is steroid resistant and the severity of the disease lies in the risk of developing end stage renal failure which occurs in nearly one half of those cases.