Abstract
Toluene diisocyanate (TDI) is the most prevalent agent in occupational asthma
(OA) in Korea. The immuno-pathologic mechanism for TDI-induced
bronchoconstriction remains to be clarified. We studied the immunohistochemical
finding of inflammatory cells in bronchial mucosa in subjects with TDI-induced
asthma. Fiberoptic bronchial biopsy specimens were obtained from nine subjects
with TDI-induced asthma. Six allergic asthma sensitive to house dust mite were
enrolled as controls. Bronchial biopsy specimens were examined by
immunohistology with a panel of monoclonal antibodies to mast cell tryptase
(AA1), secretary form of eosinophil cationic protein (EG2), pan T-lymphocyte
(CD3) and neutrophil elastase (NE). There was a significant increase in the
number of AA1+, EG2+ and NE+ cells in TDI-induced asthma compared to those of
allergic asthma (p=0.02, p=0.04, p=0.03, respectively). No significant
differences were observed in the number of CD3+ cells (p=0.27). These findings
support the view that neutrophil recruitment together with eosinophil and mast
cell, may contribute to the bronchoconstriction induced by TDI.