Serum osteoprotegerin, RANKL and fibroblast growth factor-23 in children with chronic kidney disease

Pediatr Nephrol. 2011 Jul;26(7):1105-14. doi: 10.1007/s00467-011-1870-5. Epub 2011 Apr 9.

Abstract

Osteoprotegerin (OPG), receptor activator of the nuclear factor κB ligand (RANKL) and fibroblast growth factor-23 (FGF-23) play a central role in renal osteodystrophy. We evaluated OPG/RANKL and FGF-23 levels in 51 children with chronic kidney disease (CKD) [n = 26 stage 3 or 4 (CKD3-4) and n = 25 stage 5 (CKD5)] and 61 controls. Any possible association with intact parathyroid hormone (iPTH) and bone turnover markers was also investigated. The OPG levels were lower in the CKD3-4 group (p < 0.001) and higher in the CKD5 group (p < 0.01) than in the controls, while RANKL levels did not differ. The FGF-23 levels were higher in both patient groups (p < 0.0001), while the levels of phosphate and iPTH were higher only in the CKD5 group (p < 0.0001). There were independent positive correlations between OPG and RANKL (β = 0.297, p < 0.01) and FGF-23 (β = 0.352, p < 0.05) and a negative correlation with the bone resorption marker TRAP5b (β = -0.519, p < 0.001). OPG was positively correlated with iPTH (R = 0.391, p < 0.01). An independent positive correlation between FGF-23 and phosphate (β = 0.368, p < 0.05) or iPTH (β = 0.812, p < 0.0001) was noted. In conclusion, we found that higher OPG levels in patients with CKD stage 5 correlated with the levels of RANKL, FGF-23, iPTH, and TRAP5b. These findings may reflect a compensatory mechanism to the negative balance of bone turnover. High FGF-23 levels in early CKD stages may indicate the need for intervention to manage serum phosphate (Pi) levels.

MeSH terms

  • Acid Phosphatase / blood
  • Analysis of Variance
  • Biomarkers / blood
  • Bone Remodeling
  • Case-Control Studies
  • Child
  • Child, Preschool
  • Chronic Disease
  • Female
  • Fibroblast Growth Factor-23
  • Fibroblast Growth Factors / blood*
  • Greece
  • Humans
  • Isoenzymes / blood
  • Kidney Diseases / blood*
  • Kidney Diseases / diagnosis
  • Kidney Diseases / physiopathology
  • Male
  • Osteoprotegerin / blood*
  • Parathyroid Hormone / blood
  • Phosphates / blood
  • RANK Ligand / blood*
  • Regression Analysis
  • Severity of Illness Index
  • Tartrate-Resistant Acid Phosphatase

Substances

  • Biomarkers
  • FGF23 protein, human
  • Isoenzymes
  • Osteoprotegerin
  • PTH protein, human
  • Parathyroid Hormone
  • Phosphates
  • RANK Ligand
  • TNFRSF11B protein, human
  • TNFSF11 protein, human
  • Fibroblast Growth Factors
  • Fibroblast Growth Factor-23
  • Acid Phosphatase
  • Tartrate-Resistant Acid Phosphatase