title: Serum osteoprotegerin, RANKL and fibroblast growth factor-23 in children with chronic kidney disease.
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.
authors.affiliation: Department of Child Health, Medical School, University of Ioannina, Ioannina 45110, Greece. eksiomou@yahoo.gr
authors.forename: Ekaterini
authors.initials: E
authors.lastname: Siomou
authors.forename: Anna
authors.initials: A
authors.lastname: Challa
authors.forename: Nikoleta
authors.initials: N
authors.lastname: Printza
authors.forename: Vasileios
authors.initials: V
authors.lastname: Giapros
authors.forename: Fotini
authors.initials: F
authors.lastname: Petropoulou
authors.forename: Andromachi
authors.initials: A
authors.lastname: Mitsioni
authors.forename: Fotios
authors.initials: F
authors.lastname: Papachristou
authors.forename: Constantinos J
authors.initials: CJ
authors.lastname: Stefanidis
mesh_terms: D000135:Acid Phosphatase / Q000097:blood; D000704:Analysis of Variance; D015415:Biomarkers / Q000097:blood; D016723:Bone Remodeling; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D002908:Chronic Disease; D005260:Female; D000089703:Fibroblast Growth Factor-23; D005346:Fibroblast Growth Factors / Q000097:blood*; D006115:Greece; D006801:Humans; D007527:Isoenzymes / Q000097:blood; D007674:Kidney Diseases / Q000097:blood* / Q000175:diagnosis / Q000503:physiopathology; D008297:Male; D053244:Osteoprotegerin / Q000097:blood*; D010281:Parathyroid Hormone / Q000097:blood; D010710:Phosphates / Q000097:blood; D053245:RANK Ligand / Q000097:blood*; D012044:Regression Analysis; D012720:Severity of Illness Index; D000071681:Tartrate-Resistant Acid Phosphatase
chemical_list: D015415:Biomarkers; C000717427:FGF23 protein, human; D007527:Isoenzymes; D053244:Osteoprotegerin; C470125:PTH protein, human; D010281:Parathyroid Hormone; D010710:Phosphates; D053245:RANK Ligand; C506030:TNFRSF11B protein, human; C505688:TNFSF11 protein, human; D005346:Fibroblast Growth Factors; D000089703:Fibroblast Growth Factor-23; D000135:Acid Phosphatase; D000071681:Tartrate-Resistant Acid Phosphatase