Cyclosporin in the treatment of steroid-responsive and steroid-resistant nephrotic syndrome in adults.

The effect of cyclosporin on proteinuria was studied in 11 patients with steroid-responsive nephrotic syndrome (10 minimal change nephropathy, one IgM nephropathy) and in four patients with steroid-resistant nephrotic syndrome from focal segmental glomerulosclerosis. Cyclosporin (mean initial dose 7.7 mg/kg per day) produced a complete remission of proteinuria in 15 nephrotic episodes in the ten patients with minimal-change nephropathy after a mean 14.3 days (range 7-23 days) of therapy. All patients remained in remission while receiving cyclosporin (mean duration of follow-up 147 days; range 40-230 days). However, when cyclosporin was discontinued on nine occasions in five patients, all relapsed after a mean 47.8 days (range 7-180 days). Four of the five patients were subsequently rechallenged with cyclosporin and all responded. Maintenance cyclosporin therapy to prevent relapse was not associated with any adverse effects, and there was no significant difference between the creatinine clearance before and after 30 days of therapy (86.9 +/- 19.3 and 81.7 +/- 23.5 ml/min respectively, P greater than 0.1). The patient with steroid-responsive IgM nephrotic syndrome did not respond to cyclosporin, and there was no significant effect of cyclosporin on proteinuria in the four patients with FSGS. Cyclosporin is an effective agent for the treatment of patients with frequently relapsing minimal-change nephropathy who became steroid dependent when cyclophosphamide is contraindicated. However, unlike cyclophosphamide, long-term remissions which persist after treatment is withdrawn are not obtained, and patients may be said to be cyclosporin dependent.