Bronchial Hyperreactivity Protective in Grain Dust Induced Airway Inflammation

摘要

Exposure studies were performed on five subjects with bronchial hyperreactivity(BHR) in an effort to better understand the relative importance of BHR in the physiologic and inflammatory responses of the lung following acute inhalation challenge to corn dust extract (CDE). The responses of these five subjects were compared to those from five subjects with normal airway reactivity (NAR). In the first hour following challenge, subjects with BHR complained more frequently of chest tightness and dyspnea. They also developed a significantly greater percent decline in forced expiratory volume in 1 second (FEV1) at time points 10, 20, and 30 minutes following exposure to CDE. This exaggerated decline in FEV1 did improve over time, and there were not significant differences in the percent decline at 1, 2, 3, 4, and 24 hours post exposure. In both subject groups, there were increases in bronchoalveolar lavage total cells, neutrophils, tumor necrosis factor alpha, interleukin-6, and interleukin-8 by 4 hours following inhalation of CDE but these were similar between the two groups. The authors conclude that, while the subjects with BHR develop an exaggerated initial decline in FEV1 following CDE exposure, the physiologic and inflammatory response to CDE is similar in subjects with and without BHR.