title: Levels of cysteinyl-leukotrienes in exhaled breath condensate are not due to saliva contamination.
abstract: OBJECTIVE
  Saliva contamination has been suggested to be a major contributor to levels of cysteinyl leukotrienes in exhaled breath condensate (EBC). The aim of this study was to compare the levels of cysteinyl-leukotrienes (CysLT) and alpha-amylase activity in EBC to induced sputum and saliva collected from the same subjects (asthmatics and control). We thereby aimed to find out whether saliva contamination could be a plausible explanation to the levels found in EBC or not.
  
  
  METHODS
  EBC, saliva and induced sputum were collected from 11 asthmatic and 19 healthy adults. These samples were analyzed for CysLT concentration and alpha-amylase activity.
  
  
  RESULTS
  No significant correlation was found between CysLT concentration and alpha-amylase activity in EBC, saliva or sputum. In addition, we show that the saliva contamination (measured as alpha-amylase activity) was negligible, as the relative amount of saliva CysLT was only 0.6% of that found in EBC. The amount of CysLT correlated between all three compartments (EBC, saliva and sputum), but no similar correlation was seen for the alpha-amylase activity in EBC compared to saliva and sputum. The levels of CysLT were higher in asthmatic patients compared to healthy controls in EBC, saliva and sputum.
  
  
  CONCLUSIONS
  We conclude that the amount of CysLT in EBC cannot be explained by saliva contamination. Please cite this paper as: Tufvesson E, van Weele LJ, Ekedahl H and Bjermer L. Levels of cysteinyl-leukotrienes in exhaled breath condensate are not due to saliva contamination.
authors.affiliation: Respiratory Medicine and Allergology, Department of Clinical Sciences in Lund, Lund University, Lund, Sweden. Ellen.Tufvesson@med.lu.se
authors.forename: Ellen
authors.initials: E
authors.lastname: Tufvesson
authors.forename: Linda Jacqueline
authors.initials: LJ
authors.lastname: van Weele
authors.forename: Henrik
authors.initials: H
authors.lastname: Ekedahl
authors.forename: Leif
authors.initials: L
authors.lastname: Bjermer
mesh_terms: D000328:Adult; D001249:Asthma / Q000175:diagnosis*; D001944:Breath Tests; D016022:Case-Control Studies; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D015289:Leukotrienes / Q000032:analysis*; D008297:Male; D008875:Middle Aged; D012463:Saliva / Q000737:chemistry*; D013183:Sputum / Q000737:chemistry; D055815:Young Adult; D000516:alpha-Amylases / Q000032:analysis*
chemical_list: D015289:Leukotrienes; D000516:alpha-Amylases