Systemic and local airways inflammatory response to endotoxin

Endotoxin can be detected in house dust. Numerous studies have revealed tha t endotoxin exposure is a risk factor in increasing airway obstructive mani festations, both in occupational and domestic environments. In humans, inha lation of pure endotoxin induces systemic symptoms and a change in bronchia l non-specific responsiveness, related with changes in blood and sputum inf lammatory markers. However, some recent work suggests that, prior to airway disease development, endotoxin may have an atopy-protective effect. In par ticular, indoor endotoxin exposure in early rife may protect against allerg en sensitisation by enhancing type-1 immunity. Finally, since large Variati ons between human immune responses to endotoxin have been reported, genetic mutations could alter the mechanisms of endotoxin recognition and contribu te to the risk of atopy. (C) 2000 Elsevier Science Ireland Ltd. All rights reserved.