title: Blood cytotoxic/inflammatory mediators in non-eosinophilic asthma.
abstract: BACKGROUND
  Non-eosinophilic asthma (NEA) is a distinct, often corticosteroid-resistant inflammatory asthma phenotype. NK and NKT-like cells are effector lymphocytes that we have shown, like CD28null T cells, to be relatively resistant to steroids and major sources of pro-inflammatory/cytotoxic mediators. We hypothesized that these cells and mediators would be increased in peripheral blood in NEA.
  
  
  METHODS
  Adults with severe asthma and variable airflow obstruction, poorly controlled despite maintenance therapy with inhaled glucocorticosteroids and long-acting bronchodilators, were recruited. Blood was assessed in those with eosinophilic asthma (n = 12), NEA (n = 25) and healthy non-smoking controls (n = 30). We applied flow cytometry to measure T, CD28null, NK and NKT-like cells and their expression of granzyme B, perforin, and killer inhibitory/activating receptors CD94(Kp43), CD158b and CD107A. Intracellular pro-inflammatory cytokine production (IFN-γ and TNF-α) was assessed in 18 controls and 10 patients with asthma/group.
  
  
  RESULTS
  In NEA, there was increased expression of granzyme B by CD8+ T cells vs.
  
  
  METHODS
  There was increased expression of granzyme B and CD158 and decreased CD94 on NK cells, vs. healthy controls and those with eosinophilic asthma. IFN-γ production by NK cells and TNF-α production by NKT-like cells in NEA were significantly increased vs.
  
  
  METHODS
  In both eosinophilic and NEA phenotypes, there were significant increases in CD4+28null T cells (72% and 81% increases, respectively, vs. controls) and their expression of pro-inflammatory cytokines. Significant correlations were noted between blood CD4+28null T cells and neutrophil numbers in induced sputum, and between corticosteroid dose and blood NKT-like cells, and their production of granzyme B and TNF-α and NK IFN-γ.
  
  
  CONCLUSIONS
  In poorly controlled asthma, altered expression of cytotoxic/pro-inflammatory mediators can be seen on a variety of lymphocyte subsets in the peripheral blood; these changes are most apparent in NEA. Whether this pattern of expression is a marker of treatment responsiveness and future risk of exacerbations remains to be determined.
authors.affiliation: Lung Research, Hanson Institute and Department of Thoracic Medicine, Royal Adelaide Hospital, Adelaide, SA, Australia.|Department of Medicine, University of Adelaide, Adelaide, SA, Australia.
authors.forename: S
authors.initials: S
authors.lastname: Hodge
authors.affiliation: Lung Research, Hanson Institute and Department of Thoracic Medicine, Royal Adelaide Hospital, Adelaide, SA, Australia.|Department of Medicine, University of Adelaide, Adelaide, SA, Australia.
authors.forename: G
authors.initials: G
authors.lastname: Hodge
authors.affiliation: Centre for Asthma and Respiratory Disease, The University of Newcastle, Newcastle, NSW, Australia.|Department of Respiratory and Sleep Medicine, Hunter Medical Research Institute, Newcastle, NSW, Australia.
authors.forename: J L
authors.initials: JL
authors.lastname: Simpson
authors.affiliation: School of Medicine, The University of Queensland, Brisbane, QLD, Australia.|The Prince Charles Hospital, Brisbane, QLD, Australia.
authors.forename: I A
authors.initials: IA
authors.lastname: Yang
authors.affiliation: School of Medicine, The University of Queensland, Brisbane, QLD, Australia.|Princess Alexandra Hospital, Brisbane, QLD, Australia.
authors.forename: J
authors.initials: J
authors.lastname: Upham
authors.affiliation: Department of Pulmonary Physiology and Sleep Medicine, Sir Charles Gairdner Hospital, Perth, WA, Australia.
authors.forename: A
authors.initials: A
authors.lastname: James
authors.affiliation: Centre for Asthma and Respiratory Disease, The University of Newcastle, Newcastle, NSW, Australia.|Department of Respiratory and Sleep Medicine, Hunter Medical Research Institute, Newcastle, NSW, Australia.
authors.forename: P G
authors.initials: PG
authors.lastname: Gibson
authors.affiliation: Lung Research, Hanson Institute and Department of Thoracic Medicine, Royal Adelaide Hospital, Adelaide, SA, Australia.|Department of Medicine, University of Adelaide, Adelaide, SA, Australia.
authors.forename: P N
authors.initials: PN
authors.lastname: Reynolds
mesh_terms: D000368:Aged; D001249:Asthma / Q000097:blood* / Q000175:diagnosis / Q000276:immunology*; D015415:Biomarkers; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology / Q000378:metabolism; D016207:Cytokines / Q000097:blood* / Q000378:metabolism; D005260:Female; D053804:Granzymes / Q000097:blood; D006801:Humans; D016130:Immunophenotyping; D018836:Inflammation Mediators / Q000097:blood* / Q000378:metabolism; D042541:Intracellular Space / Q000378:metabolism; D007958:Leukocyte Count; D016131:Lymphocyte Subsets / Q000276:immunology / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D054353:Perforin / Q000097:blood; D012129:Respiratory Function Tests; D012307:Risk Factors; D013183:Sputum / Q000166:cytology / Q000276:immunology
chemical_list: D015415:Biomarkers; D016207:Cytokines; D018836:Inflammation Mediators; D054353:Perforin; D053804:Granzymes
keywords: CD4+28null T cells; NK and NKT-like cells; blood; cytotoxic; non-eosinophilic asthma; pro-inflammatory cytokines