title: Immunoglobulin E and G4 antibody responses in occupational airway exposure to bovine and porcine plasma proteins.
abstract: BACKGROUND
  Production of both antigen-specific immunoglobulin (Ig)E and IgG4 antibodies is dependent on stimulation of B cells by T helper 2 cell-derived cytokines. However, there is controversy as to their interaction. In this study, we investigated the interdependency of IgE and IgG4 antibody responses to a relatively high range of airway exposure to animal-derived proteins in an occupational setting. Moreover, associations with self-reported airway symptoms and bronchial hyperresponsiveness were established.
  
  
  METHODS
  In a cross-sectional design, employees of an animal plasma spray-drying factory were questioned about airway symptoms, exposure was measured with personal sampling technique, and serology was performed. In a selection of subjects from this population, serology was repeated 15 months later, and bronchial hyperresponsiveness was measured.
  
  
  RESULTS
  IgE and IgG4 antibodies were detected in 17 and 57% of all employees and were both associated with degree of exposure. Only IgE antibodies showed an independent association with self-reported airway symptoms and bronchial hyperresponsiveness. The presence of IgE antibodies was limited to employees with high levels of IgG4. Employees with IgE and symptoms appeared to have less IgG4 than asymptomatic IgE-positive individuals. The level of specific IgG4 antibodies was stable over a 15-month period.
  
  
  CONCLUSIONS
  In high-range airway exposure, development of IgE and IgG4 antibodies depended on the level of exposure. The threshold for development of IgG4 antibodies appeared to be less than that for IgE antibodies, and IgG4 antibodies may protect against the development of symptoms.
authors.affiliation: Department of Pulmonology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands.
authors.forename: E J M
authors.initials: EJ
authors.lastname: Krop
authors.forename: S O
authors.initials: SO
authors.lastname: Stapel
authors.forename: H
authors.initials: H
authors.lastname: De Vrieze
authors.forename: J S
authors.initials: JS
authors.lastname: Van der Zee
mesh_terms: D000328:Adult; D000818:Animals; D001798:Blood Proteins / Q000276:immunology*; D016535:Bronchial Hyperreactivity / Q000097:blood / Q000209:etiology / Q000276:immunology; D002417:Cattle; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D017578:Immunoglobulin Class Switching / Q000276:immunology; D007073:Immunoglobulin E / Q000096:biosynthesis* / Q000097:blood / Q000276:immunology; D007074:Immunoglobulin G / Q000096:biosynthesis* / Q000097:blood / Q000276:immunology; D008297:Male; D016273:Occupational Exposure / Q000009:adverse effects*; D011852:Radioallergosorbent Test; D013147:Spirometry; D013552:Swine
chemical_list: D001798:Blood Proteins; D007074:Immunoglobulin G; D007073:Immunoglobulin E