title: CXC chemokine superfamily induced by Interferon-γ in asthma: a cross-sectional observational study.
abstract: BACKGROUND
  Asthma is a disease encompassing a variety of contributing factors. Phenotyping of asthma based on the profile of accumulated granulocytes in the airways has been performed to explore the mediators involved in allergic bronchial inflammation. The aim of this study was to clarify the characteristics of the CXC chemokine superfamily induced by IFN-γ, namely CXCR3 ligands, in the airways of patients with asthma stratified by the differential proportion of granulocytes in sputum.
  
  
  METHODS
  Sputum was induced in 39 adult patients with asthma and 12 healthy subjects. Sputum samples were analyzed for total cell counts and differentials, and concentrations of IFN-γ-inducible protein 10 kDa (IP-10, CXCL10), monokine induced by IFN-γ (Mig, CXCL9), IFN-inducible T cell a chemoattractant (I-TAC, CXCL11), and IL-8 in the supernatants were assayed by ELISA.
  
  
  RESULTS
  Sputum concentrations of IP-10, Mig, and IL-8 were significantly higher in asthma than in healthy subjects. IP-10, Mig, and IL-8 were significantly higher in the mixed granulocyte subtype (eosinophils ≥ 2 % and neutrophils ≥ 40 % in sputum) than in healthy subjects. Additionally, IP-1 0 was significantly higher in the mixed granulocyte subtype than in eosinophil-predominant or neutrophil-predominant subtype (eosinophil percentage ≥ 2 % or neutrophil percentage ≥ 40 %). Mig and IL-8 were significantly higher in the mixed granulocyte subtype than in the paucigranulocyte subtype (eosinophils < 2 % and neutrophils < 40 % in sputum). I-TAC was not different between healthy subjects and asthmatics or granulocyte subtypes. All CXCR3 ligands were significantly associated with the composite of the eosinophil and neutrophil ratio in patients with asthma. Only Mig was significantly correlated with the total eosinophil and neutrophil ratio in patients with asthma on adjusted partial correlation analysis. Mig and IL-8 were significantly negatively correlated with forced expiratory volume in 1 s % predicted (% FEV1) in patients with asthma.
  
  
  CONCLUSIONS
  CXCR3 ligands may serve as potent promoters in eosinophilic and neutrophilic airway inflammation in asthma.
authors.affiliation: Allergy Center, Saitama Medical University, Saitama, Japan.|Department of Respiratory Medicine, Saitama Cardiovascular and Respiratory Center, Saitama, Japan.|Department of Respiratory Medicine, Saitama Medical University, Saitama, Japan.
authors.forename: Yotaro
authors.initials: Y
authors.lastname: Takaku
authors.affiliation: Allergy Center, Saitama Medical University, Saitama, Japan.|Department of Respiratory Medicine, Saitama Medical University, Saitama, Japan.
authors.forename: Tomoyuki
authors.initials: T
authors.lastname: Soma
authors.affiliation: Allergy Center, Saitama Medical University, Saitama, Japan.|Department of Respiratory Medicine, Saitama Medical University, Saitama, Japan.
authors.forename: Yoshitaka
authors.initials: Y
authors.lastname: Uchida
authors.affiliation: Allergy Center, Saitama Medical University, Saitama, Japan.|Department of Respiratory Medicine, Saitama Medical University, Saitama, Japan.
authors.forename: Takehito
authors.initials: T
authors.lastname: Kobayashi
authors.affiliation: Allergy Center, Saitama Medical University, Saitama, Japan.|Department of Respiratory Medicine, Saitama Medical University, Saitama, Japan.
authors.forename: Kazuyuki
authors.initials: K
authors.lastname: Nakagome
authors.affiliation: Allergy Center, Saitama Medical University, Saitama, Japan.|Department of Respiratory Medicine, Saitama Medical University, Saitama, Japan.
authors.forename: Makoto
authors.initials: M
authors.lastname: Nagata
keywords: Asthma; CXCR3 ligands; Eosinophilic inflammation; IP-10; Mig; Mixed granulocytic inflammation; Neutrophilic inflammation; Sputum