EFFECTS OF ALTERNATE-DAY OR DAILY PREDNISONE TREATMENT ON GH AND CORTISOL-LEVELS IN GROWTH-RETARDED CHILDREN 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 patients afte r RTx, we studied the effect of alternate-day (group AD, n=12) and dai ly (group D, n=7) PDN treatment on the spontaneous plasma growth hormo ne (GH) and cortisol profiles, for 48 h in group AD and for 24 h in gr oup D. The maximal plasma GH response to arginine provocation (ATT) an d plasma levels of insulin-like growth factor-1 (IGF-1), IGF-2 and ser um IGF-binding proteins (IGFBP) were also determined. For both groups the PDN doses were recalculated as daily doses for comparison. The med ian PDN dose in both groups was similar, 0.15 mg/kg/day, with a range of 0.10-0.25 mg/kg/day. Glomerular filtration rate (GFR) was above 20 ml/min/1.73 m(2) in all patients. We hypothesized that alternate-day P DN therapy and even more so daily PDN therapy would have a deleterious effect on GH and cortisol secretion and would result in lower GH-depe ndent growth factors as compared to control data of healthy children. Our findings revealed that growth-retarded renal allograft patients, r eceiving either alternate-day or daily PDN therapy, have significantly lower mean plasma GH levels than controls, but normal diurnal rhythm of GH and cortisol secretion as well as normal immunoreactive IGF-1 an d -2 levels. Mean serum IGFBP-1 levels were normal, but mean serum IGF BP-3 levels were significantly increased, while a significant negative correlation was found between the GFR and serum IGFBP-3 levels. In co nclusion, growth retardation after RTx may not be solely the result of decreased GH secretion. Suboptimal renal graft function together with increased levels of IGFBP-3 and decreased IGF bioavailability may, in combination with the presumed direct effects of PDN on the growth pla te, contribute towards growth retardation following RTx.