title: Time course of endotoxin-induced airways' inflammation in healthy subjects.
abstract: Few data are available on the kinetic of the airways' inflammation induced by inhaled endotoxin in a given subject. The purpose of this study was to evaluate in healthy subjects the time-related endotoxin-induced airways' inflammation. The cells counts from the induced-sputum were evaluated before, 6 and 24 h, and 7 days after an exposure to 20 mcg inhaled endotoxin, in eight pre-selected volunteers. To avoid interference of the induced-sputum procedure on the response to endotoxin, each time-point was evaluated in randomized order at 2-weeks interval after three separate inhalations of endotoxin. A significant rise of the relative number of lymphocytes (p<0.05) and polymorphonuclear neutrophils (PMN; p<0.02) and of the absolute number of PMN (p<0.05) occurring at 6 h, followed by an increase of the absolute number of the total viable cells (p<0.01), macrophages (p<0.001), neutrophils (p<0.01), and lymphocytes (p<0.05) at 24 h after endotoxin inhalation. The inflammatory response recovered totally after 7 days. In human beings, the inhalation of endotoxin induced a transient airway inflammation after 6 h, peaked at 24 h and recovered after 7 days. When repeated endotoxin inhalations are used as a model of inflammation, a wash-out period of at least 7 days should be applied between each exposure in each subject.
authors.affiliation: Clinics of Immuno-allergology, CHU Brugmann, Université Libre de Bruxelles-ULB, pl Van Gehuchten, 4, 1020, Brussels, Belgium.
authors.forename: Virginie
authors.initials: V
authors.lastname: Doyen
authors.forename: Zaina
authors.initials: Z
authors.lastname: Kassengera
authors.forename: Duc Huy Phong
authors.initials: DH
authors.lastname: Dinh
authors.forename: Olivier
authors.initials: O
authors.lastname: Michel
mesh_terms: D000280:Administration, Inhalation; D000293:Adolescent; D000328:Adult; D004731:Endotoxins / Q000008:administration & dosage / Q000276:immunology*; D005260:Female; D006801:Humans; D007249:Inflammation / Q000276:immunology*; D008070:Lipopolysaccharides / Q000276:immunology; D018655:Lymphocyte Count; D008214:Lymphocytes; D008264:Macrophages; D008297:Male; D008875:Middle Aged; D009504:Neutrophils; D012137:Respiratory System / Q000276:immunology* / Q000473:pathology*; D013183:Sputum / Q000166:cytology*; D055815:Young Adult
chemical_list: D004731:Endotoxins; D008070:Lipopolysaccharides