Background: Reduced renal function after liver transplantation (LT) is a long-term extrahepatic complication of major concern caused at least partly by calcineurin inhibitor nephrotoxicity. We report on long-term renal function after LT in children from a single center and analyze the usefulness of glomerular filtration rate (GFR) estimation methods in the follow-up of pediatric LT patients.
Methods: Fifty-seven pediatric patients were included. GFRs were measured by 51-labeled chromium ethylenediaminetetraacetic acid clearance before LT, at discharge, 6, 12, 18, and 24 months after transplantation and annually thereafter and corrected with the modified Brochner-Mortensen equation. GFR values of cases with an ethylenediaminetetraacetic acid distribution volume less than 15% or more than 35% were excluded.
Results: The mean GFR for overall follow-up was 76.0 mL/min/1.73 m2 (+/-22.2 mL/min/1.73 m2). The GFR declined significantly from 5 to 7 years (80.2 [+/-17.7] to 72.9 [+/-13.3] mL/min/1.73 m2, respectively; P<0.05). Thirteen percent, 21%, 31%, and 33% of patients had stage 3 chronic kidney disease at 5, 7, 10, and 15 years after LT, respectively. The cyclosporine A trough level was a significant time-dependent factor in the regression model, and after time was removed from the model, proteinuria was the most significant factor. GFR estimation methods overestimated measured GFR; 11% with updated Schwartz, 50% with Schwartz 1987, and 31% with Counahan-Barratt.
Conclusions: This study underlines the importance of long-term renal function surveillance after LT performed on children. Although measuring GFR remains the preferred function surveillance method, the updated Schwartz formula is also acceptable.