title: Serum ferritin and transferrin levels as serologic markers of methylene diphenyl diisocyanate-induced occupational asthma.
abstract: BACKGROUND
  Although methylene diphenyl diisocyanate (MDI) may induce occupational asthma in the workplace, the pathogenic mechanisms are unclear.
  
  
  OBJECTIVE
  By using bronchoalveolar lavage fluid, we sought to identify proteins that were differentially expressed between subjects with MDI-induced occupational asthma (MDI-OA) and asymptomatic exposed controls (AECs).
  
  
  METHODS
  To find proteins that were differentially expressed between the MDI-OA and AEC groups, 2-dimensional electrophoresis was performed by using bronchoalveolar lavage fluid obtained from subjects after MDI-specific inhalation challenge. The selected protein spots were then identified by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. The clinical relevance of the differentially expressed spots was compared by ELISA using sera from the MDI-OA/eosinophilic bronchitis, AEC, and unexposed healthy control groups. Receiver operating characteristic curves were then plotted, and the sensitivity and specificity were determined.
  
  
  RESULTS
  Twenty-three protein spots were identified that distinguished the subjects with MDI-OA from those in the AEC group. Among them, ferritin expression was downregulated whereas transferrin expression was upregulated in subjects with MDI-OA compared with AEC; these results were validated by ELISA using sera from the MDI-OA/EB and AEC groups. To identify subjects with MDI-OA, the optimal serum cutoff levels were 69.84 ng/mL for ferritin and 2.48 microg/mL for transferrin. When these 2 parameters were combined, the sensitivity was 71.43% and the specificity was 85.71%.
  
  
  CONCLUSIONS
  Serum ferritin and transferrin levels are associated with the phenotype of MDI-OA.
authors.affiliation: Department of Allergy and Rheumatology, Ajou University School of Medicine, Suwon, South Korea.
authors.forename: Gyu-Young
authors.initials: GY
authors.lastname: Hur
authors.affiliation: Department of Allergy and Rheumatology, Ajou University School of Medicine, Suwon, South Korea.
authors.forename: Gil-Soon
authors.initials: GS
authors.lastname: Choi
authors.affiliation: Pulmonary and Critical Care Medicine, Ajou University School of Medicine, Suwon, South Korea.
authors.forename: Seung-Soo
authors.initials: SS
authors.lastname: Sheen
authors.affiliation: Department of Allergy and Rheumatology, Ajou University School of Medicine, Suwon, South Korea.
authors.forename: Hyun-Young
authors.initials: HY
authors.lastname: Lee
authors.affiliation: Department of Allergy and Rheumatology, Ajou University School of Medicine, Suwon, South Korea.
authors.forename: Han-Jung
authors.initials: HJ
authors.lastname: Park
authors.affiliation: Department of Allergy and Rheumatology, Ajou University School of Medicine, Suwon, South Korea.
authors.forename: Sung-Jin
authors.initials: SJ
authors.lastname: Choi
authors.affiliation: Department of Allergy and Rheumatology, Ajou University School of Medicine, Suwon, South Korea.
authors.forename: Young-Min
authors.initials: YM
authors.lastname: Ye
authors.affiliation: Department of Allergy and Rheumatology, Ajou University School of Medicine, Suwon, South Korea. Electronic address: hspark@ajou.ac.kr.
authors.forename: Hae-Sim
authors.initials: HS
authors.lastname: Park
mesh_terms: D000328:Adult; D001249:Asthma / Q000097:blood* / Q000139:chemically induced*; D015415:Biomarkers / Q000097:blood; D001992:Bronchoalveolar Lavage Fluid; D015180:Electrophoresis, Gel, Two-Dimensional / Q000379:methods; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D005260:Female; D005293:Ferritins / Q000032:analysis / Q000097:blood*; D006801:Humans; D007221:Industry; D017953:Isocyanates / Q000633:toxicity*; D008297:Male; D008875:Middle Aged; D016273:Occupational Exposure / Q000009:adverse effects*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods; D014168:Transferrin / Q000032:analysis*; D001559:Benzhydryl Compounds
chemical_list: D015415:Biomarkers; D005293:Ferritins; D017953:Isocyanates; D014168:Transferrin; C005969:4,4'-diphenylmethane diisocyanate; D001559:Benzhydryl Compounds