GROWTH DELAY AFTER LIVER-TRANSPLANTATION IN CHILDHOOD - STUDIES OF UNDERLYING MECHANISMS

After liver transplantation in children, growth is often impaired, but the underlying mechanisms are unknown. Glucocorticoids used for immun osuppression are believed to be partly responsible. After renal transp lantation in children, reduced growth hormone (GH) secretion and incre ased serum insulin-like growth factor-binding protein-3 (IGFBP-3) leve ls have been reported. We attempted to find endocrine factors predicti ng growth in 18 prepubertal children followed for more than 1 y (mean 2.4 y) after liver transplantation. Spontaneous and stimulated GH secr etion, serum IGF-I, IGFBP-3 concentrations, and endogenous cortisol pr oduction were measured. GH secretion was reduced in only two patients. Serum IGF-I concentration was normal, but serum IGFBP-3 was elevated or 1 SD above the mean for age in 62% of the patients. Endogenous cort isol production was reduced in most patients during the first year and improved later in only a few. Growth velocity after transplantation d id not correlate with GH secretion, serum IGF-I or IGFBP-3 concentrati on, or with methylprednisolone dose, but correlated positively with se rum basal (r(s) = 0,44, p < 0.05) and stimulated (r(s) = 0.53, p < 0.0 05) cortisol concentration. In conclusion, after liver transplantation 1) the normal pulsatile character of nocturnal GH secretion is sustai ned, and the GH response to stimulation is reduced in only a few patie nts; 2) serum IGF-I concentrations are normal; 3) serum IGFBP-3 concen trations are elevated or in the upper part of the normal range in most patients; and 4) endogenous cortisol production is reduced in most pa tients and correlates positively with growth velocity.