LEVELS OF GROWTH-HORMONE, INSULIN-LIKE GROWTH FACTOR-I (IGF-I) AND FACTOR-II, IGF-BINDING PROTEIN-1 AND PROTEIN-3, AND CORTISOL IN PREDNISONE-TREATED CHILDREN WITH GROWTH-RETARDATION AFTER RENAL-TRANSPLANTATION

Growth retardation after renal transplantation (RTx) is generally attr ibuted to prednisone (PDN) administration, although the exact mechanis m is poorly understood. In a group of 19 growth-retarded post-RTx chil dren, we studied the effect of alternate day (AD; n = 12) and daily (D ; n = 7) PDN therapy (0.10-0.25 mg/kg-day) on 24-h plasma GH and corti sol profiles, once in group D and twice on successive days in group AD . The maximal plasma GH response to arginine provocation (ATT) and pla sma levels of insulin-like growth factor-I (IGF-I), IGF-II, and serum IGF-binding proteins (IGFBP) were also determined. The pulsatile chara cter of the 24-h GH secretion was sustained in all patients. However, mean GH levels were significantly lower as compared with published dat a for healthy children, corrected for pubertal stage and sex. The high est mean GH levels were found in boys and girls in late puberty' Group AD had similar 24-h GH profiles whether on or off PDN treatment, whic h did not differ significantly from the GH profiles observed in group D. The maximal GH response during ATT was greater than 10 mug/L in 57% of the children. Group D had significantly lower mean and maximal cor tisol levels than group AD, but all patients had a normal diurnal vari ation. Plasma immunoreactive IGF-I and IGF-II, and serum IGFBP-1 level s were normal, but serum levels of IGFBP-3 were increased. A significa nt negative correlation was found between the glomerular filtration ra te and serum IGFBP-3 levels. In conclusion, our findings indicate that growth-retarded renal allograft patients, receiving either alternate day or daily PDN therapy, have decreased GH secretion, but a normal di urnal rhythm of GH and cortisol secretion as well as normal plasma IGF -I and -II levels. However, growth retardation after RTx may not solel y be the result of decreased GH secretion. Renal graft impairment toge ther with decreased IGF bioavailability may, in addition to the presum ed direct effects of PDN on cartilage, contribute to the growth retard ation after RTx.