title: Circulating antibodies to Saccharomyces cerevisiae (bakers'/brewers' yeast) in gastrointestinal disease.
abstract: OBJECTIVE
  To measure circulating antibodies to yeast organisms that could be used to characterise the yeast specific immune response in gastrointestinal disease.
  
  
  METHODS
  A quantitative, isotype specific enzyme linked immunosorbent assay was developed to measure circulating antibodies to an aqueous extract of Saccharomyces cerevisiae (sacc). Comparisons of specific antibody concentrations were made between 224 healthy controls and 51 patients with Crohn's disease, 41 with ulcerative colitis, 24 with indeterminate colitis, 23 with chronic liver disease, 17 with coeliac disease, and seven with irritable bowel syndrome. Additional comparisons were made between Crohn's disease and ulcerative colitis patients. Within the Crohn's disease group, the dependence of antibody levels on several clinical variables was assessed.
  
  
  RESULTS
  IgG and IgA anti-sacc antibodies were significantly raised in Crohn's disease. IgG antibodies were also raised in patients with chronic liver disease. Among patients with Crohn's disease, IgG antibody concentrations were higher in those with serum alpha 1 acid glycoprotein (AAG) above the normal range and there was a strong trend towards increased IgG anti-sacc in the presence of small bowel disease, whereas IgA anti-sacc correlated positively with disease duration. No differences were detected according to whether patients were taking steroids. Neither the Crohn's disease nor the chronic liver disease group differed from normal subjects in respect of IgG antibodies to bovine milk casein. On linear regression analysis of complete data from 39 Crohn's disease patients, AAG was found to be a significant predictor of both IgG and IgA antibodies, and male sex and disease duration to be additional predictors of IgA antibodies. There was a significant difference in IgG antibodies between Crohn's disease and ulcerative colitis.
  
  
  CONCLUSIONS
  Raised antibodies to yeast, although not completely specific for Crohn's disease, may have a future role in diagnosis. The assays described here could be used to address this question in the context of a prospective study.
authors.affiliation: Department of Immunology, Royal Liverpool University Hospital, UK. c.j.darroch@liverpool.ac.uk
authors.forename: C J
authors.initials: CJ
authors.lastname: Darroch
authors.forename: R M
authors.initials: RM
authors.lastname: Barnes
authors.forename: J
authors.initials: J
authors.lastname: Dawson
mesh_terms: D000328:Adult; D000367:Age Factors; D000908:Antibodies, Fungal / Q000097:blood*; D002908:Chronic Disease; D003424:Crohn Disease / Q000276:immunology; D003937:Diagnosis, Differential; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D005260:Female; D006801:Humans; D007070:Immunoglobulin A / Q000097:blood; D007074:Immunoglobulin G / Q000097:blood; D007410:Intestinal Diseases / Q000276:immunology*; D008107:Liver Diseases / Q000276:immunology; D008297:Male; D008875:Middle Aged; D012441:Saccharomyces cerevisiae / Q000276:immunology*; D012720:Severity of Illness Index; D012737:Sex Factors
chemical_list: D000908:Antibodies, Fungal; D007070:Immunoglobulin A; D007074:Immunoglobulin G