title: Alpha-1 antitrypsin is elevated in exhaled breath condensate and serum in exacerbated COPD patients.
abstract: BACKGROUND
  Exacerbations of chronic obstructive pulmonary disease (COPD) significantly contribute to COPD-related morbidity. Diagnosis of COPD exacerbations may be improved by analyzing biomarkers such as alpha-1 antitrypsin (AAT). AAT is an acute-phase protein and inhibitor of neutrophil elastase. Deficiency of AAT may result in early-onset respiratory symptoms. Measurement of exhaled breath condensate (EBC) is a noninvasive method to investigate biomarkers present in the epithelial lining fluid, such as AAT.
  
  
  OBJECTIVE
  To investigate whether AAT can be detected and quantified in EBC and to compare AAT levels in the EBC of healthy controls, patients with COPD, and during exacerbations of COPD.
  
  
  METHODS
  EBC from 10 healthy controls, 17 subjects with COPD, and 18 subjects with exacerbations of COPD was collected with the RTube™ device. AAT from EBC and serum were quantified by ELISA.
  
  
  RESULTS
  AAT in EBC was detectable in every individual. Patients with exacerbations of COPD had significantly increased AAT values (mean, 514.33 pg/mL, [SD 279.41 ]) compared with healthy controls (mean, 251.32 pg/mL, [SD 44.71]) and stable COPD patients (mean, 242.01 pg/mL [SD 65.74]) (P=0.0003; P=0.00003). EBC AAT showed only a correlation trend with serum AAT (r=0.3, P=0.054).
  
  
  CONCLUSIONS
  AAT in EBC was detectable and quantifiable. AAT measured in EBC was significantly increased during exacerbations of COPD and can potentially be used as a biomarker in exacerbations.
authors.affiliation: Department of Internal Medicine, Division for Pulmonary Diseases, Philipps-Universität Marburg, Hospital of the University of Marburg, Baldingerstrasse 1, 35043 Marburg, Germany. koczulla@med.uni-marburg.de
authors.forename: A Rembert
authors.initials: AR
authors.lastname: Koczulla
authors.forename: Sarah
authors.initials: S
authors.lastname: Noeske
authors.forename: Christian
authors.initials: C
authors.lastname: Herr
authors.forename: Janine
authors.initials: J
authors.lastname: Koepke
authors.forename: Rudolf A
authors.initials: RA
authors.lastname: Jörres
authors.forename: Christoph
authors.initials: C
authors.lastname: Nell
authors.forename: Severin
authors.initials: S
authors.lastname: Schmid
authors.forename: Claus
authors.initials: C
authors.lastname: Vogelmeier
authors.forename: Robert
authors.initials: R
authors.lastname: Bals
mesh_terms: D000208:Acute Disease; D000209:Acute-Phase Proteins / Q000378:metabolism*; D000328:Adult; D015415:Biomarkers / Q000378:metabolism; D015153:Blotting, Western; D001944:Breath Tests; D015331:Cohort Studies; D018450:Disease Progression; D004797:Enzyme-Linked Immunosorbent Assay; D045853:Exhalation; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D029424:Pulmonary Disease, Chronic Obstructive / Q000378:metabolism* / Q000503:physiopathology; D000515:alpha 1-Antitrypsin / Q000378:metabolism*
chemical_list: D000209:Acute-Phase Proteins; D015415:Biomarkers; D000515:alpha 1-Antitrypsin