title: Anti-Gal titers in healthy adults and inflammatory bowel disease patients.
abstract: BACKGROUND
  ALPHA-GAL is a glycoconjugate present on cell membranes of mammals and bacteria but not humans who display anti-Gal antibodies (AB) in high titers provoked by the commensal gut flora. In the present study, we sought to determine the longitudinal course of alpha-Gal specific AB titers of all isotypes over 8 weeks among healthy adult subjects. Furthermore, we hypothesized that inflammatory bowel disease (IBD) patients display increased anti-Gal titers.
  
  
  METHODS
  We drew serum from healthy probands (n=20) weekly for 8 weeks and obtained plasma samples of from patients suffering from Crohn's disease (n=20) and ulcerative colitis (n=20). We measured anti-Gal ABs of all isotypes and total immunoglobulin (Ig) content using an enzyme-linked immunosorbent assay technique. For statistical evaluation of the longitudinal titers, we calculated confidence intervals for the slopes of a random intercept model, comparing variances between and within the probands. For group comparisons, we performed paired student t-tests and Pearson correlations.
  
  
  RESULTS
  Alpha-Gal specific IgG, IgM, IgD, and IgA titers remained unvaried within a narrow range upon longitudinal observation. Most probands did not display alpha-Gal specific IgE ABs. Crohn's disease patients showed highly increased alpha-Gal-specific IgA titers compared with control subjects (P<.01).
  
  
  CONCLUSIONS
  Apart from IgE, alpha-Gal-specific ABs of all isotypes remained constant over longer time periods in healthy subjects. Thus, significant titer changes actually represent increased antigen exposure and a specific anti-alpha-Gal response. Crohn's disease patients display increased anti-Gal IgA titers compared with healthy controls, which reflects a chronically impaired mucosal gut barrier in this patient cohort.
authors.affiliation: Department of Thoracic Surgery, Medical University of Vienna, Vienna, Austria.
authors.forename: A
authors.initials: A
authors.lastname: Mangold
authors.forename: D
authors.initials: D
authors.lastname: Lebherz
authors.forename: P
authors.initials: P
authors.lastname: Papay
authors.forename: J
authors.initials: J
authors.lastname: Liepert
authors.forename: G
authors.initials: G
authors.lastname: Hlavin
authors.forename: C
authors.initials: C
authors.lastname: Lichtenberger
authors.forename: A
authors.initials: A
authors.lastname: Adami
authors.forename: M
authors.initials: M
authors.lastname: Zimmermann
authors.forename: D
authors.initials: D
authors.lastname: Klaus
authors.forename: W
authors.initials: W
authors.lastname: Reinisch
authors.forename: H J
authors.initials: HJ
authors.lastname: Ankersmit
mesh_terms: D000293:Adolescent; D000328:Adult; D000906:Antibodies / Q000097:blood*; D001317:Austria; D016022:Case-Control Studies; D003093:Colitis, Ulcerative / Q000276:immunology*; D003424:Crohn Disease / Q000276:immunology*; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D013997:Time Factors; D014312:Trisaccharides / Q000276:immunology*; D055815:Young Adult
chemical_list: D000906:Antibodies; D014312:Trisaccharides; C076569:alpha-galactosyl epitope