title: Induced sputum supernatant bioactive lipid mediators can identify subtypes of asthma.
abstract: BACKGROUND
  Induced sputum (IS) allows to measure mediators of asthmatic inflammation in bronchial secretions. The specific role of induced sputum supernatant (ISS) endogenous bioactive lipid mediators in subtypes of asthma is not well understood.
  
  
  OBJECTIVE
  To investigate the interactions between airway inflammation and clinical phenotypes of asthma, we integrated induced sputum supernatant (ISS) eicosanoids and quantitative assessment of infiltrating cells into new subtypes with the means of latent class analysis (LCA).
  
  
  METHODS
  One hundred and thirty-nine asthmatics with and without aspirin hypersensitivity underwent sputum induction. High-performance liquid chromatography or gas chromatography coupled with mass spectrometry was used to profile eicosanoids. Nineteen variables covering clinical characteristics, IS inflammatory cells and eicosanoids were considered in the LCA.
  
  
  RESULTS
  Four phenotypic asthma classes were distinguished. Class 1 with mild-to-moderate asthma, chronic rhinosinusitis (CRS), high PGA2 in ISS and almost equal distribution of inflammation cell patterns. Class 3 subjects also had mild-to-moderate asthma but without upper airway symptoms. Induced sputum was often paucigranulocytic with low levels of lipid mediators. Classes 2 and 4 represented severe asthma with CRS and impaired lung function despite high doses of steroids. High blood and sputum eosinophilia was in line with high cysteinyl leukotrienes and PGD2 in ISS only in class 2. Class 4 subjects tended to have increased sputum neutrophilia and PGE2 in ISS. Aspirin hypersensitivity was most frequent among class 2 subjects.
  
  
  CONCLUSIONS
  The LCA revealed four distinct asthma classes differing in eicosanoid pathways.
authors.affiliation: Department of Medicine, Jagiellonian University School of Medicine, Cracow, Poland.
authors.forename: L
authors.initials: L
authors.lastname: Mastalerz
authors.affiliation: Department of Medicine, Jagiellonian University School of Medicine, Cracow, Poland.
authors.forename: N
authors.initials: N
authors.lastname: Celejewska-Wójcik
authors.affiliation: Department of Medicine, Jagiellonian University School of Medicine, Cracow, Poland.
authors.forename: K
authors.initials: K
authors.lastname: Wójcik
authors.affiliation: Department of Medicine, Jagiellonian University School of Medicine, Cracow, Poland.
authors.forename: A
authors.initials: A
authors.lastname: Gielicz
authors.affiliation: Department of Applied Mathematics, AGH University of Science and Technology, Cracow, Poland.
authors.forename: A
authors.initials: A
authors.lastname: Ćmiel
authors.affiliation: Department of Medicine, Jagiellonian University School of Medicine, Cracow, Poland.
authors.forename: M
authors.initials: M
authors.lastname: Ignacak
authors.affiliation: Department of Medicine, Jagiellonian University School of Medicine, Cracow, Poland.
authors.forename: K
authors.initials: K
authors.lastname: Oleś
authors.affiliation: Department of Applied Mathematics, AGH University of Science and Technology, Cracow, Poland.
authors.forename: A
authors.initials: A
authors.lastname: Szczeklik
authors.affiliation: Department of Medicine, Jagiellonian University School of Medicine, Cracow, Poland.
authors.forename: M
authors.initials: M
authors.lastname: Sanak
mesh_terms: D000328:Adult; D001249:Asthma / Q000175:diagnosis* / Q000188:drug therapy / Q000209:etiology / Q000378:metabolism*; D002853:Chromatography, Liquid; D005260:Female; D006801:Humans; D018836:Inflammation Mediators / Q000378:metabolism*; D008055:Lipids / Q000737:chemistry*; D008297:Male; D013058:Mass Spectrometry; D008875:Middle Aged; D010641:Phenotype; D012129:Respiratory Function Tests; D012307:Risk Factors; D013183:Sputum / Q000737:chemistry*
chemical_list: D018836:Inflammation Mediators; D008055:Lipids
keywords: asthma phenotype; eicosanoids; induced sputum; latent class analysis