A randomized, double blind, placebo-controlled trial on safety and efficacy of recombinant human insulin-like growth factor-I in children with growth hormone receptor deficiency.

GH insensitivity due to GH receptor deficiency is a rare autosomal recessive condition, characterized by deletions or mutations of the GH receptor gene. Patients are refractory to both endogenous and exogenous GH, resulting in severe growth retardation. Therapy with recombinant human insulin-like growth factor-I (rhIGF-I) can bypass the defect in the GH receptor and potentially stimulate growth. We previously identified a genetically homogeneous group of patients in southern Ecuador, thus providing a patient base for a controlled clinical trial of rhIGF-I therapy. Seventeen prepubertal patients were entered in a randomized, double blind, placebo-controlled trial. Subjects received either a 12-month course of rhIGF-I (120 micrograms/kg, sc, daily) or 6 months of placebo followed by 6 months of rhIGF-I. Subjects receiving rhIGF-I showed a significant increase in growth rate, which was sustained over the 1-yr course of therapy (from 2.9 +/- 0.6 to 8.6 +/- 0.4 cm/yr). Incidents of hypoglycemia were equal in frequency in the placebo and rhIGF-I groups. One recipient of rhIGF-I developed papilledema, which resolved spontaneously. rhIGF-I therapy did not alter serum IGF-binding protein-3 concentrations. rhIGF-I treatment is effective in stimulating skeletal growth in GH receptor deficiency. Although the therapy proved to be safe, the potent metabolic actions of rhIGF-I and the persistently low levels of serum IGF carrier protein necessitate continued careful observation for side-effects.

Insulin-like growth factors (IGFs), IGF-binding proteins (IGFBPs), and proteolyzed IGFBP-3 in embryonic cavities in early human pregnancy: their potential relevance to maternal-embryonic and fetal interactions.

Insulin-like growth factors (IGFs) and their binding proteins (IGFBPs) are believed to be important in fetal growth and development. In the current study, the developmental changes in the IGF and IGFBP axis were examined in 23 paired samples of human amniotic fluid (AF), extraembryonic coelomic (EEC) fluid, and maternal serum (MS) between 9 and 12 weeks gestation. Levels of IGF-I were very low in AF (7 +/- 3 ng/mL) and EEC (10 +/- 3 ng/mL) compared to those in MS (237 +/- 42 ng/mL). In contrast, IGF-II concentrations were 210 +/- 36 and 174 +/- 22 ng/mL in AF and EEC, respectively, and were approximately 25% of MS serum levels (884 +/- 122 ng/mL). There was no dependence on gestational age for either peptide in AF or EEC during the period of gestation examined. IGFBP-1 levels in AF increased about 20-fold (1.6 +/- 0.3 to 33.0 +/- 0.1 ng/mL) between 9 and 12 weeks of pregnancy, and IGFBP-1 levels were nearly 2 orders of magnitude higher in EEC, increasing about 100-fold (365 +/- 119 to 3014 +/- 100.0 ng/mL) by the end of the first trimester. In contrast, IGFBP-1 levels were low in MS (24.9 +/- 3.5 ng/mL) and showed no gestational age dependence. Using RIA, high levels of IGFBP-3 were found in EEC (2062 +/- 177 ng/mL) and MS (6590 +/- 357 ng/mL) compared to those in AF (152 +/- 24 ng/mL). Levels of IGFBP-3 in MS and EEC did not change significantly with gestational age, whereas an increase in IGFBP-1 was observed in AF after the tenth week of pregnancy. In contrast to high levels of IGFBP-3 in MS and EEC, determined by RIA, the 37- to 43-kilodalton IGFBP-3 doublet was barely detectable by Western ligand blot analysis. This discrepancy suggested the presence of an IGFBP-3 protease in EEC, as has been found in MS, that decreases the affinity of this BP for IGF peptides and, therefore, renders it less readily detectable by Western ligand blot analysis. Using [125I]IGFBP-3 as substrate, lower levels of IGFBP-3 protease activity were detected in EEC compared to MS, and nearly undetectable levels were found in AF. By Western immunoblotting, a smaller (28-kilodalton) immunoreactive form of IGFBP-3 was detected only in MS and EEC, suggesting proteolyzed IGFBP-3 in MS and EEC, but not in AF, during this gestational period.(ABSTRACT TRUNCATED AT 400 WORDS)