title: Characterization of plasma cytokines in an infant population cohort of challenge-proven food allergy.
abstract: BACKGROUND
  Sensitization to food allergens indicates the production of food-specific IgE; however, sensitization is not a definite indicator of allergic reaction upon ingestion (N Engl J Med, 344, 2001, 30: J Allergy Clin Immunol, 120, 2007, 491). Currently, food challenge is the best approach to identify the presence or absence of allergy. While 95% positive predictive values (PPVs) thresholds for sIgE can assist with identifying increased likelihood of allergy among those who are sensitized, there are no specific biological markers that differentiate between allergic and sensitized individuals.
  
  
  OBJECTIVE
  To determine whether plasma serum cytokine profiles predict (i) sensitization to peanut and egg and (ii) food allergy among sensitized infants.
  
  
  METHODS
  Peanut-sensitized (PT) and egg-sensitized 14-month-old infants and nonsensitized controls enrolled in HealthNuts, a population-based study of food allergy, underwent an oral food challenge (OFC). Blood was collected within 1 h after OFC. Serum levels of Th1, Th2 and regulatory cytokines were determined in allergic (n = 79), sensitized (n = 40) and nonsensitized, nonallergic (n = 37) infants by multiplex assay.
  
  
  RESULTS
  Food-sensitized infants had significantly higher plasma IL-4, IL-13, IL-12p70 and lower IL-10 levels compared to nonsensitized infants. IL-10 and IL-6 levels were significantly higher in sensitized compared with allergic infants. Egg-allergic infants had significantly higher IL-13 and IL-12p70 levels compared to peanut-allergic (PA) infants.
  
  
  CONCLUSIONS
  Levels of Th2-related cytokines in plasma are higher in food-sensitized infants, irrespective of clinical food allergy status. In contrast, IL-10 levels appear to predict food allergy among sensitized infants. Differences in IL-13 and IL-12p70 between egg- and peanut-allergic infants could help explain the different resolution rates of the allergies.
authors.affiliation: Murdoch Childrens Research Institute, Parkville, Vic., Australia; Department of Paediatrics, University of Melbourne, Parkville, Vic., Australia.
authors.forename: T D
authors.initials: TD
authors.lastname: Dang
authors.forename: M L K
authors.initials: ML
authors.lastname: Tang
authors.forename: J J
authors.initials: JJ
authors.lastname: Koplin
authors.forename: P V
authors.initials: PV
authors.lastname: Licciardi
authors.forename: J K
authors.initials: JK
authors.lastname: Eckert
authors.forename: T
authors.initials: T
authors.lastname: Tan
authors.forename: L C
authors.initials: LC
authors.lastname: Gurrin
authors.forename: A-L
authors.initials: AL
authors.lastname: Ponsonby
authors.forename: S C
authors.initials: SC
authors.lastname: Dharmage
authors.forename: K J
authors.initials: KJ
authors.lastname: Allen
mesh_terms: D000485:Allergens / Q000009:adverse effects / Q000276:immunology; D010367:Arachis / Q000009:adverse effects; D015331:Cohort Studies; D016207:Cytokines / Q000097:blood*; D021181:Egg Hypersensitivity / Q000097:blood / Q000453:epidemiology / Q000276:immunology; D004531:Eggs / Q000009:adverse effects; D005512:Food Hypersensitivity / Q000097:blood* / Q000453:epidemiology / Q000276:immunology*; D006801:Humans; D007223:Infant; D021183:Peanut Hypersensitivity / Q000097:blood / Q000453:epidemiology / Q000276:immunology; D011159:Population Surveillance
chemical_list: D000485:Allergens; D016207:Cytokines
keywords: HealthNuts; cytokines; diagnosis; food allergy; oral food challenge