Grain dust-induced airflow obstruction and inflammation of the lower respiratory tract.

Abstract

To investigate the relationship between the physiologic and biologic effects of grain dust inhalation, we exposed 15 nonsmoking, nonasthmatic, nonatopic male grain handlers to buffered saline and aqueous corn dust extract by inhalation challenge in a crossover study. The inhalation challenges to buffered saline and corn dust extract were separated by at least 14 d. Compared with buffered saline, inhalation of corn dust extract resulted in significant airflow obstruction, which was observed within 30 min of exposure and persisted for 5 h. Inhalation of corn dust extract resulted in an acute inflammatory response characterized by higher concentrations of neutrophils (p = 0.001), IL-1 beta (p = 0.001), IL-1RA (p = 0.001), IL-6 (p = 0.001), IL-8 (p = 0.001), and TNF-alpha (p = 0.04) in bronchoalveolar lavage (BAL) fluid. mRNA levels specific for IL-1 beta, IL-1RA, IL-6, and IL-8 from cells present in the BAL fluid were significantly greater after challenge with corn dust extract than after challenge with buffered saline. Importantly, no significant differences were observed in the concentration of lymphocytes or eosinophils in the BAL fluid following inhalation of corn dust extract, and the concentrations of histamine and 15-HETE were similar in BAL fluid after the two challenges. The maximal percentage decrease in FEV1 was significantly associated with the absolute neutrophil concentration in the BAL fluid (p = 0.001), as well as the concentration of TNF-alpha (p = 0.03), IL-1 beta (p = 0.005), IL-1RA (p = 0.001), IL-6 (p = 0.001), and IL-8 (p = 0.001) in the BAL fluid.(ABSTRACT TRUNCATED AT 250 WORDS)

Identification of IgE-Binding Components in Occupational Asthma Caused by Corn Dust

“…Bronchoalveolar lavage of patients with corn dust-induced occupational asthma 12 showed a profound influx of neutrophils in the lower respiratory tract with marked increase in cytokine production (TNF ␣, IL-1␤, IL-1 receptor antagonist, IL-6, and IL-8). Clapp et al 22 indicated that grain dust extracts had physiologic effects similar to those of endotoxin.…”

“…2 Immune mechanisms may be operative in some grain handlers who develop airflow obstruction 3,4 but several lines of evidence indicate that the physiologic response to grain dust extract is mediated primarily by a nonimmunologic inflammatory response in the lower respiratory tract. [5][6][7][8][9][10][11] A recent report 12 of cytokine patterns in bronchoalveolar lavage fluid cells from corn dust-induced occupational asthma patients suggests that a predominantly nonimmunologic mechanism, an acute inflammatory response to an inhaled toxin such as endotoxin, may be involved in the development of corn dust-induced bronchoconstriction. There have been few reports regarding an IgE-mediated mechanism in occupational asthma caused by corn dust.…”

Etiology and pathogenesis of airway disease in children and adults from rural communities.

“…Naive, healthy study subjects challenged with dust from animal confinement buildings develop airflow obstruction and an increase in the serum concentration of neutrophils and interleukin (IL)-6, all of which are most strongly associated with the concentration of endotoxin (not dust) in the bioaerosol (51). Finally, our previous exposure-response studies have shown that inhaled grain dust and endotoxin produce similar physiologic and biologic effects in humans (47,52,53) and mice (53)(54)(55)(56); the and contraction of smooth muscle (62). However, the concentration of endotoxin in the bioaerosol is not always predictive of respiratory symptoms among agricultural workers (63,64).…”

Asthma durch Getreidestaub

“…Diese können symptomarm oder sogar asymptomatisch verlaufen. Weiterhin sind aber auch typische asthmatische Krankheitsbilder nach Einwirkung von Getreidestaub (Getreidestaubasthma) beschrieben [4, 6,11,12,14,21,38,39]. Chan-Yeung u. Mitarb.…”