Long-term renal function in heart transplant children on cyclosporine treatment

Renal function deterioration is a reason of concern in heart transplantation. Our aim was to evaluate long-term renal function in heart transplant children on cyclosporine (CsA) treatment and to investigate the effect of several variables possibly involved in renal function deterioration. Creatinine clearances were retrospectively reviewed in 50 children (median follow 99.7 months after heart transplant). Gender, age, and body weight at transplant, rejection episodes, CsA cumulative dose, and trough levels were analyzed. After an initial increase of the glomerular filtration rate (GFR), renal function worsened in most patients; 28% of the children developed renal insufficiency (defined as GFR 2), which was already evident in the first 3 years. Neither CsA dose, trough levels, nor other patient characteristics were found to be associated with renal function deterioration. In this study renal failure occurred in one-third of the patients. The lack of association of CsA with renal insufficiency may be explained by several reasons, including the limitations of the retrospective design of the study. However, it is possible that the nephrotoxic effect of CsA is more likely to occur in a set of predisposed patients. These must be soon identified to evaluate early a calcineurin inhibitor-sparing strategy.