EFFECT OF EXPOSURE TO SWINE DUST ON LEVELS OF IL-8 IN AIRWAY LAVAGE FLUID

Background - Inhalation of swine dust causes airway inflammation with influx of inflammatory cells, predominantly neutrophils, into the lung s. A study was undertaken to determine whether or not exposure to swin e dust induces release of interleukin 8 (IL-8) into upper and lower ai rways and how this possible release is related to cellular influx. A f urther aim was to study the relationship between the inflammatory resp onse and swine dust exposure. Methods - Thirty one healthy, non-smokin g, previously unexposed subjects were exposed to swine dust during thr ee hours work in a swine house. Bronchoalveolar lavage (BAL) was perfo rmed two weeks before and 24 hours after the exposure (n = 16). Nasal lavage and acoustic rhinometry were carried out 1-2 hours before and s even hours after the start of the exposure (n = 31). Exposure measurem ents were performed with personal sampling equipment. Results - The ex posure led to 19-fold and 70-fold increases in the neutrophil concentr ations in nasal lavage and BAL fluid, respectively (p<0.001). In BAL f luid macrophages, lymphocytes and eosinophils increased significantly. The IL-8 levels in BAL fluid increased from <31.3 ng/l to 63 (43-109) ng/l (median (25-75th percentile), p<0.001), and in nasal lavage flui d the concentrations increased from 144 (97-227) ng/l to 1064 (864-143 7) ng/l (p<0.001). IL-8 levels showed a significant correlation with t he increase in neutrophils in the nasal lavage fluid but not in the BA L fluid. Acoustic rhinometry demonstrated significant swelling of the nasal mucosa. The air concentration of inhalable dust was 23.3 (20.0-2 9.3) mg/m(3), endotoxin 1.3 (1.1-1.4) mu g/m(3), and muramic acid 0.99 (0.78-2.1) mu g/m(3). Conclusions - The concentration of IL-8 increas es in BAL fluid and nasal lavage fluid following exposure to swine dus t and may be one of the chemoattractants contributing to the recruitme nt of neutrophils to the nasal cavity and the alveolar space.