Background: Glucocorticoids are still a cornerstone in immunosuppressive regimens in pediatric patients after renal transplantation (Tx). Due to the side effects, steroid withdrawal may significantly improve the appearance and growth of children with renal grafts, but bears a substantial risk for late rejections.
Aim of the study: To investigate whether exclusion of subclinical acute rejection by renal histology in combination with a prolonged steroid withdrawal period is predictive of a successful outcome.
Patients and methods: Ten children (5 females) with a median age of 12.3 (range 7.9-20.9) years and 1.8 (0.7-7.5) years after Tx with a stable graft function and a median calculated creatinine clearance (C(Cr)) of 71 (60.5-99.7) ml/min/1.73 m2 were included. All patients showed steroid toxicity signs. Immunosuppressive regimen included low-dose steroids (median 2.72 mg/m2) in all patients, in addition to cyclosporin A (CsA) and azathioprine in 8, CsA on its own and CsA combined with mycophenolate mofetil in one patient each. A graft biopsy was performed in 8 patients prior to the start of steroid withdrawal, which was done over a median period of 6 months. Renal function was calculated as creatinine clearance using the Schwartz formula.
Results: None of the biopsied grafts showed histologic signs of rejection. Cyclosporin A dosage and trough levels were not significantly different before and after steroid withdrawal. While steroid side effects improved in most of the patients after withdrawal, C(Cr) decreased significantly within a median observation time of 42 (11.4-49.3) months. This decrease was due to loss of renal function in 4 patients who had biopsy-proven rejection episodes at 21.6 (8.1-29.9) months after the start of steroid withdrawal.
Conclusion: Slow steroid withdrawal in pediatric Tx patients using conventional immunosuppression reduces side effects, but bears a high risk of late rejection. A pre-withdrawal renal biopsy was not useful for the prediction of successful steroid withdrawal.