FOLLOW-UP-STUDY OF CHILDREN WITH NEPHROTIC SYNDROME TREATED WITH A LONG-TERM MODERATE DOSE OF CYCLOSPORINE

Because of its potential for chronic nephrotoxicity, the long-term use of cyclosporine A (CsA) as treatment for nephrotic syndrome (NS) is c ontroversial. The clinical outcome of patients with NS treated with Cs A is unclear. We retrospectively evaluated 35 children with idiopathic NS, 24 with steroid-dependent NS (SDNS), and 11 with steroid-resistan t NS (SRNS), who received CsA therapy for more than 12 months (median, 23 months) at the dosage maintaining 50 to 120 ng/mL in trough Bevel. For SDNS patients, CsA was added to prednisolone after complete remis sion was achieved. For SRNS patients, CsA was used in combination with alternate-day prednisolone. Initial renal histology showed minimal ch anges (MC) in 28 patients (including all of the patients with SDNS) an d focal segmental glomerulosclerosis (FSGS) in seven patients. The pat ients were followed up for 2 to 10.5 years (median, 6.5 years) after t he termination of the CsA therapy. In SDNS patients, the relapse rate, dosage of prednisolone, standard deviation score for height, and body mass index significantly improved during CsA treatment. The follow-up study showed the proportion of SDNS decreased to 13 of 24 (54%) patie nts. in SRNS patients, CsA therapy induced remission in 8 of 11 patien ts(73%) (complete remission in seven and incomplete remission in one). Six of 11 patients (55%) then became steroid sensitive. Post-therapy biopsies, performed in 13 patients (10 with SDNS and three with SRNS), showed mild stripped interstitial fibrosis in two SDNS patients (15%) . Long-term CsA therapy in moderate doses was effective to the patient s with SDNS and SRNS and low in incidence of nephrotoxicity. The long- term use of CsA appears to result in a decrease in the proportion of S DNS and acquisition of subsequent steroid responsiveness in SRNS. (C) 1998 by the National Kidney Foundation, Inc.