Serum insulin-like growth factor binding protein (IGFBP)-4 and IGFBP-5 in children with chronic renal failure: relationship to growth and glomerular filtration rate

• Published in: Pediatric nephrology (Berlin, West) West), 2000-07, Vol.14 (7), p.589-597
• Main Authors: Ulinski, T., Mohan, S., Kiepe, D., Blum, W. F., Wingen, A.-M., Mehls, O., Tönshoff, B.
• Format: Article
• Language: English
• Subjects: Biological activity; Cartilage; Growth hormones; Insulin; Insulin-like growth factors; Proteins
• ISSN: 0931-041X; 1432-198X
• DOI: 10.1007/s004670000361

Growth retardation in children with chronic renal failure (CRF) is partly due to an inhibition of insulin-like growth factor (IGF) activity by an excess of high-affinity IGF-binding proteins (IGFBPs). The aim of this study was to analyze the serum levels and forms of IGFBP-4 and IGFBP-5 in CRF patients using specific, recently developed radioimmunoassays (RIAs) and immunoblot analysis. We examined 89 children [age 11.5 (2.8-19.0) years] with CRF [glomerular filtration rate 26.6 (7.0-67.4) ml/min per 1.73 m2], nine of them with end-stage renal disease undergoing peritoneal dialysis. Serum-immunoreactive IGFBP-4 levels were fourfold increased in CRF (prepubertal 1080±268 ng/ml; pubertal 989±299 ng/ml) compared to healthy prepubertal controls (265±73 ng/ml). In contrast, serum IGFBP-5 levels were not significantly increased neither in prepubertal (361±120 ng/ml vs 282±75 ng/ml in controls) nor pubertal CRF children (478±165 ng/ml vs 491±80 ng/ml in controls). Immunoblot analysis showed the presence of intact as well as fragmented IGFBP-4 and IGFBP-5. Serum IGFBP-4, but not IGFBP-5, levels were inversely correlated with GFR (r=-0.39, P