title: Mineral abnormalities and long-term graft function in pediatric renal transplant recipients: a role for FGF-23?
abstract: BACKGROUND
  Although current guidelines recommend the evaluation of mineral and bone metabolism in patients with all stages of chronic kidney disease (CKD), the prevalence of altered mineral ion homeostasis in the pediatric posttransplant population is unknown. Moreover, the contribution of abnormal mineral ion metabolism to graft outcomes in this population has not been evaluated.
  
  
  METHODS
  Serum calcium, phosphorus, 25(OH)vitamin D, 1,25(OH)(2)vitamin D, parathyroid hormone (PTH) and fibroblast growth factor 23 (FGF-23) levels were evaluated 4.9 ± 0.5 years after transplantation in 68 stable pediatric renal allograft recipients. Patients were subsequently followed for 2 years.
  
  
  RESULTS
  At baseline, mean estimated glomerular filtration rate (GFR) was 60 ± 2 mL/min/1.73 m(2). Serum calcium and phosphorus values were within the reference interval. PTH values were elevated but did not differ by CKD stage. 25(OH)vitamin D levels were low in nearly half of all subjects. Tubular reabsorption of phosphate and 1,25(OH)(2)vitamin D values were lower, while FGF-23 and PTH values were higher in more advanced stages of CKD. Thirty percent of patients with FGF-23 values >110 RU/mL had a decrease in GFR of >50% (P < 0.05) and FGF-23 values predicted future episodes of rejection.
  
  
  CONCLUSIONS
  Despite normal serum calcium and phosphorus levels in the majority of prevalent pediatric renal transplant recipients, abnormalities in PTH, 25(OH)vitamin D and FGF-23 are common. FGF-23 levels may be associated with increased risk for deterioration of kidney function and episodes of rejection.
authors: Division of Pediatric Nephrology, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA. kwesseling@mednet.ucla.edu
authors: Katherine
authors: K
authors: Wesseling-Perry
authors: Eileen W
authors: EW
authors: Tsai
authors: Robert B
authors: RB
authors: Ettenger
authors: Harald
authors: H
authors: Jüppner
authors: Isidro B
authors: IB
authors: Salusky
mesh_terms: D000293:Adolescent; D000328:Adult; D002118:Calcium / Q000097:blood; D002648:Child; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D005260:Female; D000089703:Fibroblast Growth Factor-23; D005346:Fibroblast Growth Factors / Q000097:blood*; D005500:Follow-Up Studies; D005919:Glomerular Filtration Rate; D006084:Graft Rejection / Q000097:blood / Q000209:etiology* / Q000401:mortality; D006085:Graft Survival; D006801:Humans; D007676:Kidney Failure, Chronic / Q000150:complications* / Q000628:therapy; D007677:Kidney Function Tests; D016030:Kidney Transplantation / Q000009:adverse effects*; D008297:Male; D008903:Minerals / Q000097:blood*; D010281:Parathyroid Hormone / Q000097:blood; D010710:Phosphates / Q000097:blood; D011379:Prognosis; D015996:Survival Rate; D013997:Time Factors; D014807:Vitamin D / Q000097:blood; D055815:Young Adult
chemical_list: C000717427:FGF23 protein, human; D008903:Minerals; D010281:Parathyroid Hormone; D010710:Phosphates; D014807:Vitamin D; D005346:Fibroblast Growth Factors; D000089703:Fibroblast Growth Factor-23; D002118:Calcium