Clinical and immunologic findings of methylene diphenyl diisocyanate-induced occupational asthma in a car upholstery factory.
BACKGROUND
Although methylene diphenyl diisocyanate (MDI) is widely used in many industries, there have been few immunological studies of MDI-induced occupational asthma.


OBJECTIVE
We investigated the effects of MDI exposure on the clinical and immunologic condition of workers in a single car upholstery factory.


METHODS
Fifty-eight MDI-exposed workers were studied. Work-related lower-respiratory symptoms (WRRS) were identified using a questionnaire. Serum-specific IgE and IgG antibodies to MDI-human serum albumin conjugate were detected by ELISA. Atopy was evaluated using a skin prick test. MDI-induced occupational asthma was confirmed in the symptomatic workers with a positive result on an MDI-specific inhalation test.


RESULTS
Thirteen (22.4%) of the subjects complained of WRRS. MDI-induced occupational asthma was confirmed in five (8.6%) of the workers, and occupational eosinophilic bronchitis was confirmed in two (3.5%). The prevalence of specific IgG antibodies (20.7%) was higher than that of specific IgE antibodies (8.6%). The prevalence of MDI-induced occupational asthma/eosinophilic bronchitis was strongly associated with the presence of both WRRS and serum-specific IgG antibodies to an MDI-human serum albumin conjugate (P<0.01, <0.05, respectively).


CONCLUSIONS
These findings suggest that MDI could be a causative agent of occupational asthma among MDI-exposed workers. The prevalence of MDI-induced occupational asthma was 8.6%, and MDI-induced eosinophilic bronchitis was confirmed in two workers. The presence of work-related lower-respiratory symptoms and serum-specific IgG antibodies to an MDI-human serum albumin conjugate may be used to predict MDI-induced occupational asthma/eosinophilic bronchitis in MDI-exposed workers.
Hur
G-Y
GY
Department of Allergy and Rheumatology, Ajou University School of Medicine, Suwon, Korea.
Koh
D-H
DH
Choi
G-S
GS
Park
H-J
HJ
Choi
S-J
SJ
Ye
Y-M
YM
Kim
K-S
KS
Park
H-S
HS
D000328:Adult; D000906:Antibodies / Q000276:immunology; D001249:Asthma / Q000139:chemically induced / Q000276:immunology*; D001336:Automobiles; D004784:Environmental Monitoring; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D007073:Immunoglobulin E / Q000276:immunology; D007074:Immunoglobulin G / Q000276:immunology; D017953:Isocyanates / Q000009:adverse effects*; D007723:Korea; D008297:Male; D008875:Middle Aged; D009784:Occupational Diseases / Q000139:chemically induced / Q000175:diagnosis / Q000276:immunology*; D016273:Occupational Exposure / Q000009:adverse effects*; D011237:Predictive Value of Tests; D015995:Prevalence; D015203:Reproducibility of Results; D012140:Respiratory Tract Diseases / Q000139:chemically induced / Q000175:diagnosis / Q000276:immunology; D012709:Serum Albumin / Q000276:immunology; D012882:Skin Tests; D013147:Spirometry; D011795:Surveys and Questionnaires; D001559:Benzhydryl Compounds
D000906:Antibodies; D007073:Immunoglobulin E; D007074:Immunoglobulin G; D017953:Isocyanates; D012709:Serum Albumin; C005969:4,4'-diphenylmethane diisocyanate; D001559:Benzhydryl Compounds