title: IgG4 antibodies against rodents in laboratory animal workers do not protect against allergic sensitization.
abstract: BACKGROUND
  The modified Th2 response, defined as an IgG4 response in the absence of IgE, is suggested to protect against the development of allergic sensitization. However, studies suggesting this protective effect all had a cross-sectional design, making it impossible to study the development of both responses.
  
  
  OBJECTIVE
  We aimed to study the dynamics in IgG4 antibodies in relation to allergic sensitization in an occupational cohort of starting laboratory animal workers. Moreover, we studied the relation between exposure, antibody responses, atopy and self reported allergic symptoms.
  
  
  METHODS
  A total of 110 starting animal workers were followed for 2 years. IgG4 antibodies against rats and mice were assessed. Workers were tested for allergic sensitization and exposure to animal allergens was estimated. Symptom status was assessed using questionnaires.
  
  
  RESULTS
  Rat and mouse specific IgG4 antibodies were present before the development of allergy and did not significantly change over time. Allergic sensitization was related to exposure and atopic status but high levels of IgG4 showed no protective effect. In contrary, workers that developed mouse specific sensitization during follow up had higher levels of mouse specific IgG4. Symptoms were related to allergic sensitization and IgG4 levels did not influence that relationship.
  
  
  CONCLUSIONS
  IgG4 antibodies are present before IgE antibodies develop and IgG4 levels are stable over time. In our occupational cohort, the modified Th2 response had no protective effect on development of sensitization or allergic symptoms.
authors.affiliation: Department of Pulmonology, Academic Medical Center, University of Amsterdam, the Netherlands. e.j.m.krop@uu.nl
authors.forename: E J M
authors.initials: EJ
authors.lastname: Krop
authors.forename: G
authors.initials: G
authors.lastname: Doekes
authors.forename: D J J
authors.initials: DJ
authors.lastname: Heederik
authors.forename: R C
authors.initials: RC
authors.lastname: Aalberse
authors.forename: J S
authors.initials: JS
authors.lastname: van der Zee
mesh_terms: D000293:Adolescent; D000328:Adult; D000818:Animals; D000830:Animals, Laboratory / Q000276:immunology; D005260:Female; D006801:Humans; D006967:Hypersensitivity / Q000276:immunology*; D007073:Immunoglobulin E / Q000097:blood / Q000276:immunology; D007074:Immunoglobulin G / Q000097:blood* / Q000276:immunology*; D008297:Male; D017056:Medical Laboratory Personnel; D051379:Mice; D009784:Occupational Diseases / Q000276:immunology*; D051381:Rats; D012882:Skin Tests; D055815:Young Adult
chemical_list: D007074:Immunoglobulin G; D007073:Immunoglobulin E