title: Cat and dust mite allergen levels, specific IgG and IgG4, and respiratory symptoms in adults.
abstract: BACKGROUND
  Exposure to allergen may induce a modified T(H)2 response characterized by high IgG(4) levels, absence of IgE sensitization, and a decreased risk of allergic respiratory symptoms.
  
  
  OBJECTIVE
  To assess the association of IgG(4) level with allergic respiratory symptoms in a community-based sample of adults.
  
  
  METHODS
  Information on exposure to cats, respiratory symptoms, and mattress allergen levels was obtained from 2780 adults. Levels of cat and house dust mite (HDM) specific IgE, IgG, and IgG(4) were measured. The association of exposure to allergen with IgG(4) and of IgG(4) with symptoms was assessed.
  
  
  RESULTS
  Geometric mean (GM) cat specific IgG and IgG(4) was higher in subjects who had a cat that was allowed in the bedroom than in subjects without a cat (adjusted ratio of GM IgG(4), 1.41; 95% CI, 1.25-1.57). Levels of HDM specific IgG and IgG(4) were similar in subjects with undetectable and high (>20.22 microg/g) mattress Der 1 levels (adjusted ratio of GM IgG(4), 1.02; 95% CI, 0.89-1.17). There was no evidence that high cat or HDM specific IgG(4) levels were associated with less IgE sensitization or with fewer symptoms.
  
  
  CONCLUSIONS
  In this community-based sample of adults, high IgG(4) levels to cat or HDM were not associated with a lower risk of allergic respiratory symptoms.
  
  
  CONCLUSIONS
  In adults, high cat allergen exposure does not protect against respiratory symptoms.
authors.affiliation: Respiratory Epidemiology and Public Health Group, National Heart and Lung Institute, London, UK. djarvis@imperial.ac.uk
authors.forename: Deborah
authors.initials: D
authors.lastname: Jarvis
authors.forename: Jan-Paul
authors.initials: JP
authors.lastname: Zock
authors.forename: Joachim
authors.initials: J
authors.lastname: Heinrich
authors.forename: Cecilie
authors.initials: C
authors.lastname: Svanes
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Verlato
authors.forename: Mario
authors.initials: M
authors.lastname: Olivieri
authors.forename: Simona
authors.initials: S
authors.lastname: Villani
authors.forename: Michela
authors.initials: M
authors.lastname: Ponzio
authors.forename: Benedicte
authors.initials: B
authors.lastname: Leynaert
authors.forename: Jordi
authors.initials: J
authors.lastname: Sunyer
authors.forename: Anna
authors.initials: A
authors.lastname: Dahlman-Hoglund
authors.forename: Susan
authors.initials: S
authors.lastname: Chinn
authors.forename: Christina
authors.initials: C
authors.lastname: Luczynska
authors.forename: Dan
authors.initials: D
authors.lastname: Norbäck
authors.forename: Peter
authors.initials: P
authors.lastname: Burney
mesh_terms: D000328:Adult; D000367:Age Factors; D000485:Allergens / Q000097:blood*; D000818:Animals; D039741:Antigens, Dermatophagoides / Q000276:immunology; D060829:Arthropod Proteins; D001249:Asthma / Q000175:diagnosis*; D002415:Cats / Q000276:immunology*; D003546:Cysteine Endopeptidases; D040002:Dermatophagoides pteronyssinus / Q000276:immunology*; D004391:Dust / Q000276:immunology*; D005260:Female; D006801:Humans; D006967:Hypersensitivity; D007073:Immunoglobulin E / Q000097:blood; D007074:Immunoglobulin G / Q000097:blood*; D008297:Male; D012130:Respiratory Hypersensitivity / Q000175:diagnosis*; D012737:Sex Factors; D012907:Smoking
chemical_list: D000485:Allergens; D039741:Antigens, Dermatophagoides; D060829:Arthropod Proteins; D004391:Dust; D007074:Immunoglobulin G; D007073:Immunoglobulin E; D003546:Cysteine Endopeptidases; C451159:Dermatophagoides farinae antigen f 1; C451162:Dermatophagoides pteronyssinus antigen p 1