title: IgG and IgG4 antibodies in subjects with irritable bowel syndrome: a case control study in the general population.
abstract: BACKGROUND
  Patients with Irritable Bowel Syndrome (IBS) often relate their symptoms to the intake of food and modify their diet. IgE-mediated food allergy is uncommon in IBS, but the role of IgG-mediated food hypersensitivity remains inconclusive. The primary aim of this study was to compare food- and yeast-specific IgG and IgG4 antibodies in subjects with and without IBS.
  
  
  METHODS
  This was a case control study in the general population for which subjects completed questionnaires about abdominal complaints and their intake of common food items. Blood samples were collected, and food- and yeast-specific IgG and IgG4 antibodies were measured. Antibodies were measured in mg/L.
  
  
  RESULTS
  We included 269 subjects with IBS and 277 control subjects. After correction for subject characteristics and diet, there were no significant differences with regard to food- and yeast-specific IgG and IgG4 antibodies between subjects with IBS and controls. Lower values of IgG antibodies against egg (OR 0.99 (0.98 to 1.00), p = 0.002) and beef (OR 0.75 (0.60 to 0.94), p = 0.012) and higher values of IgG antibodies against chicken (OR 1.14 (1.03 to 1.27), p = 0.009) were associated with more severe symptoms.
  
  
  CONCLUSIONS
  Our findings suggest that IgG-and IgG4-mediated food and yeast hypersensitivity in IBS is unlikely. IgG antibodies against food and yeast may reflect the diet.
authors.affiliation: Department of Medicine, Innlandet Hospital Trust, Kyrre Grepps gt 19, 2819, Gjøvik, Norway. solveig.ligaarden@ntnu.no
authors.forename: Solveig C
authors.initials: SC
authors.lastname: Ligaarden
authors.forename: Stian
authors.initials: S
authors.lastname: Lydersen
authors.forename: Per G
authors.initials: PG
authors.lastname: Farup
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D004032:Diet; D005260:Female; D005512:Food Hypersensitivity / Q000097:blood / Q000276:immunology; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood / Q000276:immunology*; D043183:Irritable Bowel Syndrome / Q000097:blood / Q000276:immunology*; D008297:Male; D008875:Middle Aged; D012720:Severity of Illness Index; D011795:Surveys and Questionnaires; D015003:Yeasts / Q000276:immunology
chemical_list: D007074:Immunoglobulin G