A prospective trial of steroid cessation after renal transplantation in pediatric patients treated with cyclosporine and mizoribine.

We conducted a multi-center prospective study to evaluate the safety and efficacy of steroid withdrawal after renal transplantation in children. In 52 children (51 living-related donor transplants and 1 cadaver donor transplant), immunosuppressive therapy was started with cyclosporine (CyA), mizoribine (MZ), methylprednisolone (MPL) and anti-lymphocyte globulin. Administration of MPL was reduced to alternate days more than 6 months after transplantation, and attempts were made to withdraw it. Acute rejection was noted in 19 patients (36.5%) by 1 month after transplantation. The whole-blood CyA trough level using monoclonal antibody was 175.0+/-17.0 ng/ml in patients who developed acute rejection and 282.0+/-25.3 ng/ml in those who did not show acute rejection (p<0.01). During the 37 attempts at alternate-day MPL administration, clinical acute rejection was observed in only 1 patient and chronic rejection in 3. During 10 attempts to withdraw MPL, acute rejection was noted in 3 patients, but graft function recovered to the pre-rejection level after treatment of the acute rejection. At the last observation, graft function was lost in 3 patients, 22 were receiving MPL on alternate days, and MPL had been withdrawn from 7 for a mean period of 16.7 months. The survival rate of the patients and the grafts was 100% and 94% after an average follow-up period of 4 years. Evaluation of growth showed catch-up growth in all patients during the withdrawal period.