Importance of airway inflammation for late asthmatic reactions induced by toluene diisocyanate in sensitized subjects.

To determine the importance of airway inflammation for late asthmatic reactions and increased airway responsiveness induced by TDI, we investigated whether late asthmatic reactions and increased responsiveness induced by TDI are associated with airway inflammation and whether steroids prevent them by modifying the inflammatory response within the airways. We measured FEV1 before and at regular intervals after exposure to TDI and performed dose-response curves to methacholine and bronchoalveolar lavage 8 hr after TDI in two subjects with previously documented late asthmatic reaction; then we repeated the same procedure a few weeks after treatment with steroids. Airway responsiveness and polymorphonuclear cells were increased in both subjects after the late asthmatic reaction; treatment with steroids prevented late asthmatic reaction and the increase in airway responsiveness and polymorphonuclear cells in bronchoalveolar lavage. These results suggest that late asthmatic reaction induced by TDI may be caused by airway inflammation.