Renal Function After Pediatric Cardiac Transplantation: The Effect of Early Cyclosporin Dosage

Abstract

Background. There is little data on renal function in pediatric heart transplant recipients. Early rejection is a major concern and most units run high cyclosporin A (CyA) levels during the 2 to 3 months after transplantation. We sought to document long-term renal function after transplantation and to assess influence of early CyA levels. Methods. We reviewed all of our pediatric transplants between June 1985 and August 1998 who survived longer than 6 months (n = 54). Glomerular filtration rate (GFR) was estimated at 1, 2, 4, and 8 years posttransplantation using the Schwartz formula: GFR (mL/min/1.73m2) = [Ht(cm)/creatinine(μmol/L)] × X We also analyzed whether change in renal function correlated with trough CyA levels. Results. Median age at transplant was 4 years and median follow-up was 5 years. Survival rates were 87% at 1 year and 80% at 5 years. Mean GFR pretransplant was 79 ± 19 mL/min/1.73 m2, reflecting prerenal impairment. One year later, mean GFR was 72 mL/min/1.73 m2; after 2 years it was 65 mL/min/1.73 m2, after 4 years (n = 35) it was 60 mL/min/1.73 m2, and after 8 years (n = 14) it was 57 mL/min/1.73 m2. CyA levels during the first 2 months correlated with the change in GFR during the first year (r2 = 0.21). Conclusions. This study demonstrates for the first time that decline in renal function after heart transplantation correlates with early CyA exposure; this dysfunction persists even when CyA doses are subsequently reduced.