title: Bronchoalveolar lavage fluid cytology and cytokine messenger ribonucleic Acid expression of racehorses with exercise intolerance and lower airway inflammation.
abstract: BACKGROUND
  There is limited information relating bronchoalveolar lavage (BAL) cytology and cytokine messenger ribonucleic acid (mRNA) expression in racehorses with inflammatory airway disease (IAD). HYPOTHESIS AND OBJECTIVE: We hypothesize that cytokine expression in BAL cells would correlate with cytology. Thus, we evaluated the mRNA expression of selected cytokines in BAL cells in racehorses with exercise intolerance and lower airway inflammation.
  
  
  METHODS
  Thirty-one client-owned Standardbred racehorses with exercise intolerance.
  
  
  METHODS
  Prospective, observational study. Cells were obtained by BAL, and mRNA expression of interleukin (IL)-1β, IL-4, IL-8, tumor necrosis factor (TNF)-α, and interferon (IFN)-γ was determined by reverse transcription quantitative polymerase chain reaction (RT-qPCR).
  
  
  RESULTS
  Nine horses had normal BAL cell differential cytology (Controls), while 22 horses had evidence of IAD based on BAL fluid cytology. Relative expressions of TNF-α/glyceraldehyde 3-phosphate dehydrogenase (GAPDH; 0.0092 ± 0.010 versus 0.0045 ± 0.005, P= .034), IL-4/GAPDH (0.001 ± 0.002 versus 0.0003 ± 0.0003, P= .029), and IFN-γ/GAPDH (0.0027 ± 0.003 versus 0.0009 ± 0.001, P= .028) were greater in horses with IAD compared with controls. Furthermore, IL-4/GAPDH (0.001 ± 0.002 versus 0.0002 ± 0.0003, P < .0001) and IFN-γ/GAPDH (0.003 ± 0.003 versus 0.001 ± 0.001, P= .002) mRNA expression was increased in horses with increased metachromatic cell counts compared with horses with normal metachromatic cell counts. Only the mRNA expression of IL-1β/GAPDH (1.1 ± 0.7 versus 0.3 ± 0.3, P= .045) was increased with airway neutrophilia.
  
  
  CONCLUSIONS
  Differences in gene expression were associated with the presence of IAD and with specific cell types present in airway secretions of Standardbred racehorses with poor performance. These findings suggest that different pathophysiological pathways are implicated in IAD.
authors.affiliation: Département de Sciences Cliniques, Faculté de médecine vétérinaire, Université de Montréal, Saint-Hyacinthe, QC, Canada. jean-pierre.lavoie@umontreal.ca
authors.forename: J P
authors.initials: JP
authors.lastname: Lavoie
authors.forename: C
authors.initials: C
authors.lastname: Cesarini
authors.forename: A
authors.initials: A
authors.lastname: Lavoie-Lamoureux
authors.forename: K
authors.initials: K
authors.lastname: Moran
authors.forename: S
authors.initials: S
authors.lastname: Lutz
authors.forename: V
authors.initials: V
authors.lastname: Picandet
authors.forename: D
authors.initials: D
authors.lastname: Jean
authors.forename: M
authors.initials: M
authors.lastname: Marcoux
mesh_terms: D000818:Animals; D001980:Bronchi / Q000276:immunology / Q000378:metabolism; D001992:Bronchoalveolar Lavage Fluid / Q000166:cytology*; D016207:Cytokines / Q000378:metabolism*; D005260:Female; D005786:Gene Expression Regulation / Q000276:immunology; D006734:Horse Diseases / Q000235:genetics / Q000276:immunology* / Q000378:metabolism; D006736:Horses; D008171:Lung Diseases / Q000276:immunology / Q000662:veterinary*; D008297:Male; D010805:Physical Conditioning, Animal; D011446:Prospective Studies; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000662:veterinary
chemical_list: D016207:Cytokines; D012333:RNA, Messenger