Modulation of plasma levels of soluble adhesion molecules and nitric oxide in healthy volunteers by exposure to swine dust.

Short-time exposure to swine dust causes an intense airways inflammation and symptoms of systemic inflammation in healthy volunteers. Here, we sought to study whether this response involved signs of endothelial cell activation. Peripheral blood cell counts and plasma levels of sE-selectin, sP-selectin, sICAM-1, interleukin-8, nitrite and nitrate were measured in blood samples from 17 healthy subjects before and after a 3-hr exposure to swine dust in a swine confinement building. Dust exposure induced a 3-fold increase of blood neutrophil p = 0.0009) and 1.5-fold increase of monocyte counts (p = 0.0047). IL-8 was detected in 15 individuals after exposure (p = 0.001). Endothelial cell markers such as sICAM and nitrate increased by 10 and 34% resp. (p = 0.011 and 0.017), whereas sE-selectin remained unchanged and sP-selectin was reduced by 15% (p = 0.031). Thus, short time exposure to swine dust induced a systemic inflammatory response with evidence of endothelial and inflammatory cell activation.