Grain dust-induced airflow obstruction and inflammation of the lower respiratory tract.
Clapp-WD; Becker-S; Quay-J; Watt-JL; Thorne-PS; Frees-KL; Zhang-X; Koren-HS; Lux-CR; Schwartz-DA
Am J Respir Crit Care Med 1994 Sep; 150(3):611-617
This study examined whether inhalation of grain dust could cause an inflammatory response in the lower respiratory tract of grain handlers and whether the production of several important cytokines was involved in this response. The study population was selected from 200 grain handlers in eastern Iowa. The study subjects had a mean age of 34.7 years and had been employed a mean of 10.1 years in the grain handling industry. Of the 15 subjects, eight worked exclusively with corn and seven worked at sites that processed mixed grains. None of the subjects had ever smoked. Corn dust inhalation caused a profound inflammatory response in the lower respiratory tract characterized by a neutrophilic alveolitis with enhanced cytokine production and release. Clinically relevant declines in forced expiratory volume in 1 second (FEV1), forced expiratory vital capacity (FVC) and FEV1/FVC were observed. Significantly higher cell concentrations, comprised primarily of neutrophils, were noted in bronchoalveolar lavage (BAL) fluid. All cytokines measured in BAL were elevated significantly above levels seen after saline challenge. The concentrations of 15-hydroxyeicosatetraenoic-acid, prostaglandin-E2, leukotriene-B4, and histamine in BAL, however, did not differ following challenge with corn dust compared to buffered saline. The concentrations of mRNA for interleukin-1-beta (IL1- beta), IL-1RA, IL-6, IL-8, and tumor-necrosis-factor-alpha were significantly greater in BAL cells following inhalation of corn dust. The authors note a relationship between the physiologic response and the inflammatory response and conclude that the results suggest that the airway response to grain dust represents an acute inflammatory response to an inhaled toxin.
NIOSH-Grant; NIOSH-Cooperative-Agreement; Pulmonary-system-disorders; Airway-obstruction; Respiratory-system-disorders; Dust-inhalation; Dust-exposure; Grain-dusts; Lung-irritants; Pulmonary-function-tests; Airway-resistance
Internal Medicine University of Iowa Pulmonary Disease Division Iowa City, IA 52242
Grant; Cooperative Agreement
American Journal of Respiratory and Critical Care Medicine
University of Iowa, Iowa City, Iowa