Cyclosporine in idiopathic nephrotic syndrome

Idiopathic nephrotic syndrome encompasses two main forms of glomerular diseases, minimal change nephropathy and focal segmental glomerulosclerosis. Minimal change nephropathy is a disease of children which generally responds to corticosteroids. After remission, however, many patients show frequent relapses or steroid dependency. In these patients, cyclosporine may obtain remission of proteinuria in 80% of cases, although relapse usually occurs when the drug is stopped. Focal glomerulosclerosis is generally resistant to corticosteroids. Under cyclosporine some 40% of patients may attain complete or partial remission of the nephrotic syndrome particularly if low-dose prednisone is associated. Relapse of proteinuria usually occurs after stopping the drug. As cyclosporine may expose to chronic nephrotoxicity some guidelines should be followed to prevent this complication: - the doses should not exceed 5 mg/Kg/day - they should be adjusted whenever an increase in plasma creatinine of > or = 30% over the baseline values occurs - treatment should be stopped if there is no response within 3 months - a careful monitoring of patient under the supervision of a clinician trained with the use of cyclosporine is necessary. The term idiopathic nephrotic syndrome (INS) defines the association of a nephrotic syndrome with non specific glomerular lesions, in the absence of immune complex deposition (1). On the basis of renal histology two main types of INS are recognized: minimal change nephropathy (MCN) and focal and segmental glomerular sclerosis (FSGS).