CELLULAR AND MEDIATOR PROFILE IN BRONCHOALVEOLAR LAVAGE OF GUINEA-PIGS AFTER TOLUENE DIISOCYANATE (TDI) EXPOSURE

Toluene diisocyanate (TDI) is a volatile, highly reactive chemical wid ely used as a polymerizing agent in the production of polyurethane foa ms, lacquers, adhesives, and other items. Repeated airway exposures in the workplace to TDI may cause a concentration-dependent ri sk of dev eloping chronic airway disorders. Different pathomechanisms are involv ed. IgE-mediated sensitization and irritative effects were clearly dem onstrated in exposed subjects as well as in animals. In this study we examined the cellular and mediator composition in bronchoalveolar lava ge fluid (BALF) of guinea pigs (eight in each group) exposed to TDI (1 0, 20, or 30 ppb) on 5 consecutive days for 2 hours each. Increased nu mbers of eosinophils and significantly elevated levels of LTB(4) and L TC(4)/LTD(4)/LTE(4) were obtained in BALF of ail exposed animals when compared to nonexposed control animals. PGD(2) and TXB(2) remained una ltered in BALF. Stimulation of BALF cells of exposed and control anima ls with Ca-ionophore A23187 and arachidonic acid induced an increased generation of LTB(4). Furthermore, BALF cells of the exposed animal gr oups generated immunoreactive LTC(4)/LTD(4)/LTE(4), whereas controls d id not show peptido-leukotriene formation in the presence and absence of stimuli. Our data clearly demonstrate an influx of eosinophils into the airways associated with mediator release and higher cellular resp onsiveness after TDI exposure.