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The significance of specific IgG4 antibodies to methyltetrahydrophthalic anhydride in occupationally exposed subjects
Author(s) -
Sho Yokota,
Naohito Yamaguchi,
Takeshita,
○ Morimoto
Publication year - 1998
Publication title -
clinical and experimental allergy
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.462
H-Index - 154
eISSN - 1365-2222
pISSN - 0954-7894
DOI - 10.1046/j.1365-2222.1998.00293.x
Subject(s) - immunoglobulin e , medicine , antibody , immunology , serology , odds ratio , population , specific antibody , logistic regression , toxicology , biology , environmental health
Background A definitive role for allergen‐specific IgG4 as either an anaphylactic or a blocking antibody, or both, remains controversial. Objective A population of 148 workers from two condenser plants (A and B) using epoxy resin with methyltetrahydrophthalic anhydride (MTHPA) was studied to evaluate the significance of MTHPA‐specific IgG4 antibody. Methods The workers were evaluated through questionnaire and serological investigations. Results Ninety‐seven (66%) of the currently exposed workers had positive MTHPA‐specific IgE. IgE‐sensitized workers in each plant had significantly more eye and nose complaints than unsensitized workers ( P < 0.03). As the result of multiple logistic analysis, specific IgE antibodies was the most important predictor of work‐related symptoms and its effect was greater than that of specific IgG4 (odds ratio 16.7 and 3.68, respectively). These indicate an IgE‐mediated mechanism in most cases of work‐related symptoms associated with MTHPA exposure. However, it cannot be denied that specific IgG4 is an anaphylactic antibody. Furthermore, IgE‐sensitized workers in these plants displayed work‐related symptoms despite the presence of specific IgG4. The frequency of positive specific IgG4 in continuously exposed workers was significantly ( P < 0.02) higher in plant A than in plant B, reflecting the difference of the MTHPA levels between the two plants. In plant A, the frequency of positive specific IgG4 was significantly ( P < 0.002) higher in continuously exposed workers than in intermittently exposed workers. Multiple regression analysis also confirmed that plant and exposure style contributed significantly ( P < 0.01) to the determination of specific IgG4 levels. Conclusion These results suggest that work‐related eye and nasal symptoms are likely to be IgE‐mediated, and that specific IgG4 may reflect the intensity of MTHPA exposure and may not act as a blocking antibody.