title: Stage-dependent association of BDNF and TGF-β1 with lung function in stable COPD.
abstract: BACKGROUND
  Chronic Obstructive Pulmonary Disease (COPD) is characterised by complex inflammatory, neuronal and fibrotic changes. Brain-derived Neurotrophic Factor (BDNF) is a key regulator of neuronal plasticity, whereas Transforming Growth Factor-β1 (TGF-β1) plays a crucial role in tissue repair and emphysema pathogenesis. Both mediators are stored in platelets and released from platelets in inflammatory conditions and during serum preparation. In patients with asthma, it was previously shown that elevated serum BDNF concentrations correlate with disease severity, whereas TGF-β1 concentrations were normal.
  
  
  METHODS
  In the present study, 63 patients with stable COPD (spirometric GOLD stages 2-4) and 17 age- and comorbidity-matched controls were studied. Lung function, smoking history, medication, platelet concentrations in peripheral blood and serum concentrations of BDNF, TGF-β1 and Serotonin (5-HT) were assessed in all participants.
  
  
  RESULTS
  Serum levels of both BDNF and TGF-β1 (but not concentrations of platelets in peripheral blood) were significantly elevated in all stages of COPD as compared to controls. Highest BDNF concentrations were found in spirometric GOLD stage 3, whereas highest TGF-β1 serum levels were found in spirometric GOLD stage 4. There were specific, stage-dependent correlations of these mediators with lung function parameters of the patients.
  
  
  CONCLUSIONS
  Taken together, we show that, in contrast to asthma, COPD is characterised by elevated concentrations of both BDNF and TGF-β1 in serum. The stage-dependent association with lung function supports the hypothesis that these platelet mediators may play a role in the pathogenesis of COPD.
authors.affiliation: Department of Pneumology and Critical Care Medicine, University of Rostock, Ernst Heydemann Strasse 6, 18057, Rostock, Germany. paul.stoll@med.uni-rostock.de
authors.forename: Paul
authors.initials: P
authors.lastname: Stoll
authors.forename: Urs
authors.initials: U
authors.lastname: Wuertemberger
authors.forename: Kai
authors.initials: K
authors.lastname: Bratke
authors.forename: Christiana
authors.initials: C
authors.lastname: Zingler
authors.forename: J Christian
authors.initials: JC
authors.lastname: Virchow
authors.forename: Marek
authors.initials: M
authors.lastname: Lommatzsch
mesh_terms: D000368:Aged; D019208:Brain-Derived Neurotrophic Factor / Q000097:blood*; D005540:Forced Expiratory Flow Rates; D006801:Humans; D008168:Lung / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D011014:Pneumonia / Q000150:complications* / Q000503:physiopathology*; D029424:Pulmonary Disease, Chronic Obstructive / Q000145:classification / Q000150:complications* / Q000503:physiopathology*; D053773:Transforming Growth Factor beta1 / Q000097:blood*
chemical_list: D019208:Brain-Derived Neurotrophic Factor; D053773:Transforming Growth Factor beta1