Within the past decade, there have been numerous reports on the use of
cyclosporine in idiopathic
nephrosis. In this review, the results of both uncontrolled and controlled studies of the
therapeutic effects of
cyclosporine in
steroid-sensitive/dependent idiopathic
nephrosis and in
steroid-resistant idiopathic
nephrosis are analyzed.
Cyclosporine is efficient in up to 80% of patients with
steroid-sensitive/dependent idiopathic
nephrosis. Most patients, however, relapse when the
drug is withdrawn, thus necessitating prolonged treatments. Although
cyclosporine is less efficient in patients with
steroid-resistant idiopathic
nephrosis, a few studies seem to indicate that this
drug may be successful in some patients, especially if combined with
corticosteroids. There is no evidence that
cyclosporine can prevent the recurrence of
nephrotic syndrome on the graft after
renal transplantation. However, in patients in whom disease has recurred, high doses of
cyclosporine may be effective alone or in combination with
plasma exchanges. The main worrisome side effect of
cyclosporine is chronic nephrotoxicity, which should be differentiated from acute or "functional" toxicity. Follow-up studies including pretreatment and posttreatment renal biopsies show a lack of correlation between structural damage and renal function, suggesting that a histologic examination of the renal parenchyma is the only reliable way of evaluating chronic
cyclosporine nephrotoxicity.