Treatment with cyclosporin of patients with idiopathic nephrotic syndrome.

Abstract

The prognosis of idiopathic nephrotic syndrome was transformed with the use of corticosteroids and immunosuppressive drugs. The high percentage of initial remission in minimal change lipoid nephrosis should not obscure the frequency of development to corticodependence or of multiple relapses which lead to the complications of protracted corticosteroid therapy. Focal-segmental glomerulonephritis and membranous glomerulopathy often evolve to relentless chronic renal failure. The use of immunosuppressive therapy has reduced the percentage of unfavourable evolution, but these cytotoxic agents are not devoid of short-term side effects and entail some long-term risk of malignancy [6, 26, 27]. The prognosis in cases which resist any form of treatment is distinctly unfavourable. As for the earlier forms of therapy, the use of cyclosporin in treating idiopathic nephrosis is empirical: the mechanism of immunosuppression with CyA is a continuing puzzle and the physiopathology of nephrosis is poorly understood. Moreover, cyclosporin, in contrast with conventional treatments, entails a definite risk of renal toxicity. Despite these drawbacks, preliminary results showed that approximately two-thirds of patients with idiopathic nephrotic syndrome resistant to other therapy clearly benefited from cyclosporin treatment, whereas only 7% suffered severe side effects. These results justify studies of cyclosporin treatment on a larger scale. The goal of these studies should be threefold: first, to delineate more precisely the indications and contra-indications of cyclosporin in glomerular diseases, to avoid anarchic prescription of this powerful but expensive and potentially dangerous drug; second, to determine the percentage of patients who will become dependent on long-term cyclosporin; and third, to specify the risk of nephrotoxicity in case of such protracted treatment.