title: Biomonitoring Hexamethylene diisocyanate (HDI) exposure based on serum levels of HDI-specific IgG.
abstract: OBJECTIVE
  Isocyanate chemicals essential for polyurethane production are widely used industrially, and are increasingly found in consumer products. Asthma and other adverse health effects of isocyanates are well-documented and exposure surveillance is crucial to disease prevention. Hexamethylene diisocyanate (HDI)-specific serum immunoglobulin G (IgG) was evaluated as an exposure biomarker among workers at a US Air Force Air Logistics Center, which includes a large aircraft maintenance facility.
  
  
  METHODS
  HDI-specific IgG (HDI-IgG) titers in serum samples (n = 74) were measured using an enzyme-linked immunosorbent assay based upon the biuret form of HDI conjugated to human albumin. Information on personal protective equipment (PPE), work location/tasks, smoking, asthma history, basic demographics, and HDI skin exposure was obtained through questionnaire.
  
  
  RESULTS
  HDI-specific serum IgG levels were elevated in n = 17 (23%) of the workers studied. The prevalence and/or end-titer of the HDI-IgG was significantly (P < 0.05) associated with specific job titles, self-reported skin exposure, night-shift work, and respirator use, but not atopy, asthma, or other demographic information. The highest titers were localized to specific worksites (C-130 painting), while other worksites (generator painting) had no or few workers with detectable HDI-IgG.
  
  
  CONCLUSIONS
  HDI-specific immune responses (IgG) provide a practical biomarker to aid in exposure surveillance and ongoing industrial hygiene efforts. The strategy may supplement current air sampling approaches, which do not assess exposures via skin, or variability in PPE use or effectiveness. The approach may also be applicable to evaluating isocyanate exposures in other settings, and may extend to other chemical allergens.
authors.affiliation: Department of Internal Medicine, Yale Occupational and Environmental Medicine Program, Yale University School of Medicine, New Haven, CT 06520-8057, USA. adam.wisnewski@yale.edu
authors.forename: Adam V
authors.initials: AV
authors.lastname: Wisnewski
authors.forename: Meredith H
authors.initials: MH
authors.lastname: Stowe
authors.forename: Abby
authors.initials: A
authors.lastname: Nerlinger
authors.forename: Paul
authors.initials: P
authors.lastname: Opare-Addo
authors.forename: David
authors.initials: D
authors.lastname: Decamp
authors.forename: Christopher R
authors.initials: CR
authors.lastname: Kleinsmith
authors.forename: Carrie A
authors.initials: CA
authors.lastname: Redlich
mesh_terms: D000328:Adult; D000368:Aged; D001249:Asthma / Q000139:chemically induced* / Q000276:immunology / Q000517:prevention & control; D015415:Biomarkers / Q000032:analysis / Q000097:blood; D003485:Cyanates / Q000009:adverse effects / Q000032:analysis*; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D007074:Immunoglobulin G / Q000032:analysis* / Q000097:blood / Q000276:immunology; D017953:Isocyanates; D008297:Male; D008875:Middle Aged; D016273:Occupational Exposure / Q000009:adverse effects*; D010150:Paint / Q000009:adverse effects; D011140:Polyurethanes / Q000009:adverse effects; D055815:Young Adult
chemical_list: D015415:Biomarkers; D003485:Cyanates; D007074:Immunoglobulin G; D017953:Isocyanates; D011140:Polyurethanes; C015262:1,6-hexamethylene diisocyanate