Final height and its predictive factors after renal transplantation in childhood

Abstract

A retrospective study is reported assessing final height (FH) and its predictive factors in 52 patients (31 male, 21 female) who underwent renal transplantation (RTx) before the age of 15 y. They received prednisone daily or on alternate days as well as azathioprine. The study period covered 20 y. FH remained below the third height percentile [height standard deviation score for chronologic age (hSDSCA) < -1.88] for most of these patients (77% males, 71% females). Median (range) FH was 165.0 (143.0-176.8) cm in males and 153.0 (135.0-168.4) cm in females. Median difference between FH and target height was 15.0 and 15.4 cm for males and females, respectively. For both sexes, the median hSDSCA was already below -1.88 at the start of the first hemodialysis, after which it decreased significantly until the first RTx. After RTx, there was no significant improvement of hSDSCA. The predictive factors for FH were determined by evaluating various factors simultaneous in a multiple regression analysis. This analysis provided a regression equation for predicting FH. A higher hSDSCA at the time of the first RTx and alternate-day versus daily prednisone therapy both had a significantly positive influence on FH, whereas a longer duration of reduced GFR (< 50 mL/min/1.73 m2) had a significantly negative effect on FH. Other factors such as age or bone age at first RTx, primary renal disease, duration of initial dialysis, repeat RTx, and the cumulative dose of prednisone did not influence FH significantly. In conclusion, 71-77% of patients that received their first renal transplant before the age of 15 ended up with severely short adult stature. Optimization of the hSDSCA at first RTx appears very important. Long-term administration of prednisone on alternate days would then result in optimal FH, particularly if the GFR remains above 50 mL/min/1.73 m2.