title: Relationship between cytokine expression patterns and clinical outcomes: two population-based birth cohorts.
abstract: BACKGROUND
  Models that incorporate patterns of multiple cytokine responses to allergens, rather than individual cytokine production, may better predict sensitization and asthma.
  
  
  OBJECTIVE
  To characterize the patterns of peripheral blood mononuclear cells' (PBMCs) cytokine responses to house dust mite (HDM) allergens among children from two population-based birth cohorts using machine learning techniques.
  
  
  METHODS
  PBMCs collected at 8 years of age from the UK Manchester Asthma and Allergy Study (n = 268) and at 14 years of age from the Australian Raine Study (n = 1374) were cultured with HDM extract (10 μg/ml). Cytokine expression (IL-13, IL-5, IFN-γ, and IL10) was measured in the supernatant. Cytokine patterns were identified using a Gaussian mixture model clustering, and classification stability was assessed by bootstrapping.
  
  
  RESULTS
  A six-class model indicated complex latent structure of cytokine expression. Based on the characteristics of each class, we designated them as follows: 'Nonresponders' (n = 905, 55%); 'IL-10 responders' (n = 49, 3%); 'IFN-γ and IL-13 medium responders' (n = 56, 3.4%); 'IL-13 medium responders' (n = 351, 21.4%); 'IL-5 and IL-13 medium responders' (n = 77, 4.7%); and 'IL-13 and IL-5 high responders' (n = 204, 12.4%). 'IL-13 and IL-5 high responders' were at much higher risk of HDM sensitization and asthma compared to all other classes, with 88% of children assigned to this class being sensitized and 28.5% having asthma.
  
  
  CONCLUSIONS
  Using model-based clustering, we identified several distinct patterns of cytokine response to HDM and observed interplay between cytokine expression level, cytokine patterns (especially IL-13 and IL-5), and clinical outcomes. 'IL-13 and IL-5 high responders' class was strongly associated with HDM sensitization. However, among HDM-sensitized children, one-third showed no PBMC response to HDM, and the majority of HDM-sensitized children did not have asthma or wheeze. Our findings suggest that positive HDM 'allergy tests' and asthma are associated with a broad range of immunophenotypes, which may have important implications for the use of cytokine-targeted treatment approaches.
authors.affiliation: Centre for Respiratory Medicine and Allergy, Institute of Inflammation and Repair, University of Manchester, University Hospital of South Manchester NHS Foundation Trust, Manchester, UK.
authors.forename: J
authors.initials: J
authors.lastname: Wu
authors.affiliation: Centre for Respiratory Medicine and Allergy, Institute of Inflammation and Repair, University of Manchester, University Hospital of South Manchester NHS Foundation Trust, Manchester, UK.|Centre for Health Informatics, Institute of Population Health, University of Manchester, Manchester, UK.
authors.forename: M C F
authors.initials: MC
authors.lastname: Prosperi
authors.affiliation: Centre for Respiratory Medicine and Allergy, Institute of Inflammation and Repair, University of Manchester, University Hospital of South Manchester NHS Foundation Trust, Manchester, UK.
authors.forename: A
authors.initials: A
authors.lastname: Simpson
authors.affiliation: Telethon Institute for Child Health Research, Centre for Child Health Research, University of Western Australia, Perth, WA, Australia.
authors.forename: E M
authors.initials: EM
authors.lastname: Hollams
authors.affiliation: Queensland Children's Medical Research Institute, the University of Queensland, Brisbane, Qld, Australia.
authors.forename: P D
authors.initials: PD
authors.lastname: Sly
authors.affiliation: Centre for Respiratory Medicine and Allergy, Institute of Inflammation and Repair, University of Manchester, University Hospital of South Manchester NHS Foundation Trust, Manchester, UK.
authors.forename: A
authors.initials: A
authors.lastname: Custovic
authors.affiliation: Telethon Institute for Child Health Research, Centre for Child Health Research, University of Western Australia, Perth, WA, Australia.|Queensland Children's Medical Research Institute, the University of Queensland, Brisbane, Qld, Australia.
authors.forename: P G
authors.initials: PG
authors.lastname: Holt
mesh_terms: D000485:Allergens / Q000276:immunology; D039741:Antigens, Dermatophagoides; D001315:Australia / Q000453:epidemiology; D002648:Child; D015331:Cohort Studies; D016207:Cytokines / Q000378:metabolism*; D005260:Female; D006801:Humans; D006967:Hypersensitivity / Q000453:epidemiology* / Q000276:immunology / Q000378:metabolism*; D007073:Immunoglobulin E / Q000097:blood / Q000276:immunology; D007963:Leukocytes, Mononuclear / Q000276:immunology / Q000378:metabolism; D008297:Male; D063868:Patient Outcome Assessment; D062486:Public Health Surveillance
chemical_list: D000485:Allergens; D039741:Antigens, Dermatophagoides; D016207:Cytokines; D007073:Immunoglobulin E
keywords: MAAS; Raine Study; asthma; cytokine pattern; house dust mite allergens; sensitization