Systemic and local airways inflammatory response to endotoxin

Endotoxin can be detected in house dust. Numerous studies have revealed that endotoxin exposure is a risk factor in increasing airway obstructive manifestations, both in occupational and domestic environments. In humans, inhalation of pure endotoxin induces systemic symptoms and a change in bronchial non-specific responsiveness, related with changes in blood and sputum inflammatory markers. However, some recent work suggests that, prior to airway disease development, endotoxin may have an atopy-protective effect. In particular, indoor endotoxin exposure in early rife may protect against allergen sensitisation by enhancing type-1 immunity. Finally, since large Variations between human immune responses to endotoxin have been reported, genetic mutations could alter the mechanisms of endotoxin recognition and contribute to the risk of atopy. (C) 2000 Elsevier Science Ireland Ltd. All rights reserved.