Repeated exposure to organic material alters inflammatory and physiological airway responses

¹ Lung and Allergy Research, Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden

^* To whom correspondence should be addressed. E-mail: Britt-Marie.Sundblad{at}ki.se.

	Abstract

Farmers and smokers are repeatedly exposed to airborne organic material. We hypothesised that farmers and smokers show altered airway responses to inhaled organic, pro-inflammatory agents.

Eleven farmers, 12 smokers and 12 controls underwent lipopolysaccharide (LPS) bronchial challenge and spent 3 hours in a pig barn. Lung function, exhaled nitric oxide and bronchial responsiveness were assessed and we also collected nasal lavage fluid and induced sputum. Symptoms and body temperature were recorded before and after exposures.

Following exposure to the pig barn, bronchial responsiveness, exhaled NO, sputum IL-6, nasal lavage cell count and IL-8 were increased to a greater extent in controls compared to farmers. The sputum IL-6 response was also attenuated in farmers after LPS challenge. The response shown by smokers following exposure to the pig barn was similar to controls regarding measurements of exhaled NO, IL-8 in nasal lavage and IL-6 in sputum, but more similar to farmers concerning bronchial responsiveness and the cell numbers present in nasal lavage. Sputum interleukin-8 showed a greater increase in smokers than in the other groups following LPS challenge.

We conclude that individuals who are repeatedly exposed to organic material develop an adaptation to the effects of acute exposure to inhaled organic material.