title: IgE and IgG binding patterns and T-cell recognition of Fel d 1 and non-Fel d 1 cat allergens.
abstract: BACKGROUND
  Cat allergy affects approximately 15% of the population and is a major risk factor for asthma. The relative importance of cat allergens other than Fel d 1 is not known.
  
  
  OBJECTIVE
  To compare IgE and IgG antibody binding and T-cell recognition of the major cat allergen Fel d 1 with other cat proteins with known IgE binding properties.
  
  
  METHODS
  IgE, IgG1, and IgG4 antibody to Fel d 1, 2, 3, 4, 7, 8, and the undesignated IgE binding proteins haptoglobin and S100A12 were measured in the plasma of 96 individuals with cat allergy and 78 individuals without cat allergy. Cytokines were measured from T cells stimulated with the cat allergens.
  
  
  RESULTS
  An allergen other than Fel d 1 had the highest IgE binding specificity for 35% of individuals with cat allergy, and it bound more than 50% of their IgE antibody in 70% of these sera. Fel d 4, 7, and 8 were identified as the main contributors to the non-Fel d 1 IgE binding response and elicited inflammatory Th2 cytokines to a similar degree as Fel d 1. As expected, the average percentage of IgE binding to Fel d 1 for individuals was 55%. IgG4 binding to Fel d 1 was detected in both subjects with allergy (30%) and subjects without allergy (19%). IgG4 binding to the other allergens was less prevalent but was found for both groups. IgG1 antibody was not detected to any of the newly described cat proteins.
  
  
  CONCLUSIONS
  Fel d 4, 7, and 8 are allergens that should be included in the diagnosis and investigation of cat allergy.
authors.affiliation: Telethon Institute for Child Health Research and Centre for Child Health Research, University of Western Australia, Subiaco Wa, Australia. Electronic address: belinda@ichr.uwa.edu.au.
authors.forename: Belinda J
authors.initials: BJ
authors.lastname: Hales
authors.affiliation: Telethon Institute for Child Health Research and Centre for Child Health Research, University of Western Australia, Subiaco Wa, Australia.
authors.forename: Lee Ying
authors.initials: LY
authors.lastname: Chai
authors.affiliation: Telethon Institute for Child Health Research and Centre for Child Health Research, University of Western Australia, Subiaco Wa, Australia.
authors.forename: Lee
authors.initials: L
authors.lastname: Hazell
authors.affiliation: Telethon Institute for Child Health Research and Centre for Child Health Research, University of Western Australia, Subiaco Wa, Australia.
authors.forename: Claire E
authors.initials: CE
authors.lastname: Elliot
authors.affiliation: Telethon Institute for Child Health Research and Centre for Child Health Research, University of Western Australia, Subiaco Wa, Australia.
authors.forename: Shane
authors.initials: S
authors.lastname: Stone
authors.affiliation: Telethon Institute for Child Health Research and Centre for Child Health Research, University of Western Australia, Subiaco Wa, Australia.
authors.forename: Serena E
authors.initials: SE
authors.lastname: O'Neil
authors.affiliation: Telethon Institute for Child Health Research and Centre for Child Health Research, University of Western Australia, Subiaco Wa, Australia.
authors.forename: Wendy-Anne
authors.initials: WA
authors.lastname: Smith
authors.affiliation: Telethon Institute for Child Health Research and Centre for Child Health Research, University of Western Australia, Subiaco Wa, Australia.
authors.forename: Wayne R
authors.initials: WR
authors.lastname: Thomas
mesh_terms: D000485:Allergens / Q000276:immunology; D000818:Animals; D002415:Cats; D016207:Cytokines / Q000378:metabolism; D006023:Glycoproteins / Q000276:immunology*; D006801:Humans; D006967:Hypersensitivity / Q000276:immunology*; D007073:Immunoglobulin E / Q000378:metabolism*; D007074:Immunoglobulin G / Q000378:metabolism*; D007963:Leukocytes, Mononuclear / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology
chemical_list: D000485:Allergens; D016207:Cytokines; D006023:Glycoproteins; D007074:Immunoglobulin G; D007073:Immunoglobulin E; C059296:Fel d 1 protein, Felis domesticus
keywords: Cat allergens; Cytokines; IgE; IgG1; IgG4