KIDNEY-FUNCTION IN CYCLOSPORINE-TREATED PEDIATRIC HEART-TRANSPLANT RECIPIENTS

Background: End-stage kidney disease may develop in 1% to 3% of cyclos porine-treated heart transplant recipients, and most patients show a d ecreased glomerular filtration rate. There are little data on kidney f unction in pediatric recipients, although good function is needed for their optimal development. Methods: Kidney function was prospectively investigated in 10 children receiving triple immunosuppression (cyclos porine, azathioprine, methylprednisolone) during the first 18 months a fter heart transplantation. The early cyclosporine trough level target was 300 to 500 mu g/L and 100 to 200 mu g/L after the first year. (51 )Chromium-ethylene diamine tetraacetic acid, para-amino hippuric acid, lithium, and sodium clearances, measurements of serum and urinary ele ctrolytes, and urinary concentration tests were performed. Renal biops y specimens were obtained from four patients after 18 months. Results: Heart function was good in all patients. Six patients (60%) remained rejection-free at 18 months. The mean glomerular filtration rate was 9 2.4 ml/min/1.73 m(2) before transplantation, increased to 115 by 6 mon ths (p < 0.05), and thereafter remained stable. The mean renal plasma flow was 487 ml/min/1.73 m(2) after 18 months. Hypertension was seen i n all patients at discharge but in only one at 18 months. Mild hyperur icemia was the most common sign of tubular dysfunction occurring in fi ve patients at discharge but in only two patients at 18 months. The re sult of kidney histopathologic study was normal in three of four patie nts, and cyclosporine nephrotoxicity was not diagnosed. Conclusions: T riple immunosuppression with cyclosporine adequately protects the graf t against acute rejection. It is compatible with normal glomerular fun ction and leads to only minor tubular disturbances.