title: Cat sensitization according to cat window of exposure in adult asthmatics.
abstract: BACKGROUND
  In adults, there is limited information on tolerance to cat, which may be reflected by high IgG4 without IgE sensitization. Early exposure to cat may play a critical role.
  
  
  OBJECTIVE
  The aim was to assess among adults the association of Fel d 1 IgG4, Fel d 1 IgE, skin prick test (SPT) response to cat and pet-related symptoms in relation to exposure to cat considering the period of exposure.
  
  
  METHODS
  SPT response to cat, specific IgE and IgG4 to Fel d 1 were assessed in 167 asthmatics recruited in chest clinics (40 years of age in average) from the French Epidemiological study on the Genetics and Environment of Asthma (EGEA). Childhood and/or current exposure to cat were studied retrospectively.
  
  
  RESULTS
  IgG4 was higher in relation to current cat exposure (0.53 vs. 0.09 ng/mL; P<0.001) and higher in women than in men. The period of cat exposure was significantly related to Fel d 1 IgE, the IgE/IgG4 pattern and cat weal size. The lowest values of Fel d 1 IgE, cat weal size, pet-related nasal or respiratory symptoms were observed in those with both childhood and current exposure as well as the highest proportion of the IgE-/IgG4+ pattern observed in 1.4%, 4.0%, 38.1% and 12.5% of those with -/-, +/-, +/+, -/+ childhood/current exposure, respectively.
  
  
  CONCLUSIONS
  Adult asthmatics exposed to cats since childhood present an immunologic pattern with high IgG4 and low IgE. Continuous exposure may maintain a state of immunological tolerance to cat.
authors.affiliation: INSERM, U780, Epidemiology and Biostatistics, Villejuif, France.
authors.forename: M-P
authors.initials: MP
authors.lastname: Oryszczyn
authors.forename: R
authors.initials: R
authors.lastname: Van Ree
authors.forename: J
authors.initials: J
authors.lastname: Maccario
authors.forename: R
authors.initials: R
authors.lastname: Nadif
authors.forename: F
authors.initials: F
authors.lastname: Kauffmann
mesh_terms: D000328:Adult; D000485:Allergens / Q000009:adverse effects*; D000818:Animals; D001249:Asthma / Q000097:blood* / Q000453:epidemiology; D016022:Case-Control Studies; D002415:Cats; D005260:Female; D005602:France; D006023:Glycoproteins / Q000009:adverse effects*; D006801:Humans; D007073:Immunoglobulin E / Q000097:blood*; D007074:Immunoglobulin G / Q000097:blood*; D008297:Male; D012737:Sex Factors
chemical_list: D000485:Allergens; D006023:Glycoproteins; D007074:Immunoglobulin G; D007073:Immunoglobulin E; C059296:Fel d 1 protein, Felis domesticus