Longitudinal changes in inflammatory markers in nasal lavage of cotton workers - Relation to endotoxin exposure and lung function changes

Objectives: The aim of this study was to evaluate time-related changes in inflammatory markers in nasal lavage (NAL) in relation to endotoxin exposure and lung function changes. Methods: Endotoxin in cotton dust is well known to elicit proinflammatory mediators involved in acute or chronic respiratory inflammation due to cotton dust. We applied nasal lavage as well as lung function and exposure measurements in a small group (n = 11) of cotton workers during 6 weeks of observation (after 2 weeks free of exposure). Several inflammatory markers in NAL, such as interleukin 8 (IL-8), IL-6, and down-stream mediators, including soluble tumor necrosis factor receptor 75 (sTNF-R75) and soluble intercellular adhesion molecule 1 (ICAM-1), cell counts, marker of epithelial response (uric acid), and marker of plasma exudation (albumin) were measured. Results: At the exposure levels examined in this study [cotton dust, geometric mean (GM) = 1.10 mg/m(3); endotoxin, GM = 2,869 EU/m(3)], several inflammatory markers in NAL such as IL-8, sTNF-R75, and albumin tended to increase through the measurement period with increasing airborne endotoxin concentration (in six workers who had paired measurements in weeks 1 and 6). Although no statistical significance was reached, airborne endotoxin exposure and all inflammatory markers in NAL were relatively higher in cotton workers with a 6-week lung function decrease. Conclusion: The data suggest that inflammatory markers in NAL are associated with repeated airborne endotoxin exposure.