Blood inflammatory response to inhaled endotoxin in normal subjects

Abstract

Summary Previously we have reported that in asthmatics an inhalation of 20 μg lipopolysaccharide (LPS) produces a bronchial obstruction associated with an inflammatory blood response. The aim of the present study was to evaluate this response in normal subjects. Eight normal non-atopic subjects were challenged by inhalation of a solution containing 20 μg LPS (from Escherichia coli 026:B6) a week after bronchial challenge with control solution. The lung function response was evaluated by the changes in forced expiratory volume in one second (FEV 1 ), in specific conductance and in airway resistance while the blood inflammatory response was evaluated by serial measures of total white blood cells (WBC) and polymorphonuclear neutrophils (PMN) count, luminol enhanced-chemiluminescence (luminol-CL, as a marker of the PMN degree of activation), C-reactive protein (CRP), haptoglobin, complement fraction C3, tumour necrosis factor-α (TNF-α) and adrenocorticotropic hormone (ACTH). No response in lung function was observed for 6 h after the LPS inhalation. The count in WBC and PMN increased 300 ( P P P P P P