title: Elevated transforming growth factor-beta 1 (TGF-β1) levels in human fracture healing.
abstract: BACKGROUND
  Transforming growth factor-beta 1(TGF-β1) is a regulatory protein, involved in bone fracture healing. Circulating TGF-β1 levels have been reported to be a predictor of delayed bone healing and non-union, suggesting active relationship between tissue and circulating TGF-β1 in fracture healing. The purpose of this study was to analyse TGF-β1 local and serum concentrations in fracture healing to further contribute to the understanding of molecular regulation of fracture healing.
  
  
  METHODS
  Serum samples of 113 patients with long bone fractures were collected over a period of 6 months following a standardised time schedule. TGF-β1 serum concentrations were measured using ELISA. Patients were assigned to 2 groups: Group 1 contained 103 patients with physiological healing. Group 2 contained 10 patients with impaired healing. Patients in both groups were matched. One patient of the group 2 had to be excluded because of missing match partner. In addition, fracture haematoma from 11 patients of group 1 was obtained to analyse local TGF-β1 concentrations. 33 volunteers donated serum which served as control.
  
  
  RESULTS
  TGF-β1 serum concentrations increased during the early healing period and were significantly higher in patients with physiological healing compared to controls (P=0.04). Thereafter, it decreased continuously between weeks 2 and 8 and fell again after week 8. TGF-β1 serum concentrations in patients with physiological healing were significantly higher at week 24 compared to controls (P=0.05). In non-unions, serum concentrations differed significantly from those of controls at week 6 (P=0.01). No significant difference in between patients with physiological and impaired fracture healing was observed. Fracture haematoma contained significantly higher TGF-β1 concentrations than peripheral serum of the patients (P=0.017).
  
  
  CONCLUSIONS
  Elevated levels of TGF-β1 in haematoma and in serum after bone fracture especially during the entire healing process indicate its importance for fracture healing.
authors.affiliation: Department of Traumatology, Medical University of Vienna, Waehringer Guertel 18-20, Vienna, Austria. kambiz.sarahrudi@meduniwien.ac.at
authors.forename: Kambiz
authors.initials: K
authors.lastname: Sarahrudi
authors.forename: Anita
authors.initials: A
authors.lastname: Thomas
authors.forename: Mehdi
authors.initials: M
authors.lastname: Mousavi
authors.forename: Georg
authors.initials: G
authors.lastname: Kaiser
authors.forename: Julia
authors.initials: J
authors.lastname: Köttstorfer
authors.forename: Mathias
authors.initials: M
authors.lastname: Kecht
authors.forename: S
authors.initials: S
authors.lastname: Hajdu
authors.forename: S
authors.initials: S
authors.lastname: Aharinejad
mesh_terms: D000328:Adult; D000368:Aged; D000704:Analysis of Variance; D015415:Biomarkers / Q000378:metabolism; D005260:Female; D005264:Femoral Fractures / Q000378:metabolism* / Q000503:physiopathology; D017102:Fracture Healing / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D013978:Tibial Fractures / Q000378:metabolism* / Q000503:physiopathology; D053773:Transforming Growth Factor beta1 / Q000378:metabolism*; D055815:Young Adult
chemical_list: D015415:Biomarkers; C508960:TGFB1 protein, human; D053773:Transforming Growth Factor beta1