IgG antibodies against microorganisms and atopic disease in Danish adults: The Copenhagen Allergy Study

• Published in: Journal of allergy and clinical immunology Vol. 111; no. 4; pp. 847 - 853
• Main Authors: Linneberg, Allan, Østergaard, Christian, Tvede, Michael, Andersen, Leif Pervical, Nielsen, Niels Henrik, Madsen, Flemming, Frølund, Lars, Dirksen, Asger, Jørgensen, Torben
• Format: Journal Article
• Language: English
• Published: United States Mosby, Inc 01.04.2003; Elsevier Limited
• Subjects: Adolescent; Adult; Aged; Allergies; Animals; Antibodies, Bacterial - blood; Antibodies, Protozoan - blood; Colorectal cancer; Cross-Sectional Studies; Helicobacter pylori - immunology; Hepatitis A Antibodies - blood; Humans; Hypersensitivity - etiology; Immunoglobulin G - blood; Infections; Middle Aged; Respiratory diseases; Studies; Toxoplasma - immunology; Denmark; Italy; Sweden
• ISSN: 0091-6749; 1097-6825
• DOI: 10.1067/mai.2003.1335

Background: Seropositivity to food-borne and orofecal microorganisms (hepatitis A virus, Helicobacter pylori, and Toxoplasma gondii), which are considered to be markers of poor hygiene, has been reported to be associated with a lower prevalence of atopy. In contrast, colonization of the gut with Clostridium difficile, a potential intestinal bacterial pathogen, in early childhood may be associated with a higher prevalence of atopy. Objective: The objective of this study was to investigate the association between atopy and exposure to 2 groups of food-borne and orofecal microorganisms: (1) markers of a poor hygiene and (2) intestinal bacterial pathogens. Methods: A cross-sectional population-based study of 15- to 69-year-olds living in Copenhagen, Denmark, was carried out in 1990 to 1991. Atopy was defined as a positive test result for specific IgE to at least 1 of 6 inhalant allergens. Exposure to microorganisms was assessed as IgG seropositivity to microorganisms. Results: Seropositivity to 2 or 3 markers of poor hygiene (hepatitis A virus, H pylori, and T gondii) was associated with a lower prevalence of atopy (adjusted odds ratio, 0.5; 95% CI, 0.3 to 0.8). In contrast, seropositivity to 2 or 3 intestinal bacterial pathogens ( C difficile, Campylobacter jejuni, and Yersinia enterocolitica) was associated with a higher prevalence of atopy (adjusted odds ratio, 1.7; 95% CI, 1.2 to 2.6). Conclusion: Exposure to markers of poor hygiene was associated with a lower prevalence of atopy, whereas exposure to intestinal bacterial pathogens was associated with a higher prevalence of atopy. These findings raise the hypothesis that different groups of food-borne and orofecal microorganisms may have different effects on the risk of atopy. (J Allergy Clin Immunol 2003;111:847-53.)