title: Exposure to household endotoxin and total and allergen-specific IgE in the US population.
abstract: BACKGROUND
  Although endotoxin has strong pro-inflammatory properties, endotoxin-allergy relationship in adults and children have been inconsistent.
  
  
  OBJECTIVE
  We investigated the association between household endotoxin levels and total immunoglobulin E (IgE) or specific IgE in the US general population, classified into three age ranges: children/adolescent, adults, and older adults.
  
  
  METHODS
  We analyzed the 2005-2006 National Health and Nutrition Examination Surveys. A total of 5220 participants for whom serum IgE and household endotoxin data were available was included in the analyses.
  
  
  RESULTS
  Exposure to endotoxin reduced the risk for allergic sensitization, especially in specific IgE to plants (OR in Quartile 3 = 0.58; 95% CI = 0.44-0.76) and pets (OR in Quartile 3 = 0.62; 95% CI = 0.41-0.92), for children/adolescents. In contrast, the risk among adults and older adults increased with increasing endotoxin levels.
  
  
  CONCLUSIONS
  Our findings suggest that the effect of endotoxin on allergic reaction is likely to depend on age.
authors: Department of Preventive Medicine, College of Medicine, Seoul National University, Seoul, Republic of Korea.
authors: Kyoung-Bok
authors: KB
authors: Min
authors: Institute of Health and Environment, School of Public Health, Seoul National University, Seoul, Republic of Korea. Electronic address: yaemin00@snu.ac.kr.
authors: Jin-Young
authors: JY
authors: Min
mesh_terms: D000293:Adolescent; D000328:Adult; D000391:Air Microbiology; D016902:Air Pollution, Indoor / Q000706:statistics & numerical data*; D002648:Child; D004731:Endotoxins / Q000032:analysis*; D004781:Environmental Exposure / Q000706:statistics & numerical data*; D005260:Female; D006801:Humans; D006967:Hypersensitivity; D007073:Immunoglobulin E / Q000097:blood*; D008297:Male; D010944:Plants; D055815:Young Adult
chemical_list: D004731:Endotoxins; D007073:Immunoglobulin E
keywords: Allergy sensitization; Household dust; Hygiene hypothesis; Lipopolysaccharides