title: Distinct patterns of IgG and IgA against food and microbial antigens in serum and feces of patients with inflammatory bowel diseases.
abstract: BACKGROUND
  Inflammatory bowel disease (IBD) is associated with a defective intestinal barrier and enhanced adaptive immune responses against commensal microbiota. Immune responses against food antigens in IBD patients remain poorly defined.
  
  
  METHODS
  IgG and IgA specific for food and microfloral antigens (wheat and milk extracts; purified ovalbumin; Escherichia coli and Bacteroides fragilis lysates; mannan from Saccharomyces cerevisiae) were analyzed by ELISA in the serum and feces of patients with Crohn's disease (CD; n = 52 for serum and n = 20 for feces), ulcerative colitis (UC; n = 29; n = 17), acute gastroenteritis/colitis (AGE; n = 12; n = 9) as well as non-inflammatory controls (n = 61; n = 39).
  
  
  RESULTS
  Serum anti-Saccharomyces cerevisiae antibodies (ASCA) and anti-B. fragilis IgG and IgA levels were increased in CD patients whereas antibody (Ab) levels against E. coli and food antigens were not significantly different within the patient groups and controls. Subgroup analysis revealed that CD patients with severe diseases defined by stricturing and penetrating lesions have slightly higher anti-food and anti-microbial IgA levels whereas CD and UC patients with arthropathy have decreased anti-food IgG levels. Treatment with anti-TNF-α Abs in CD patients was associated with significantly decreased ASCA IgG and IgA and anti-E. coli IgG. In the feces specific IgG levels against all antigens were higher in CD and AGE patients while specific IgA levels were higher in non-IBD patients. Anti-food IgG and IgA levels did not correlate with food intolerance.
  
  
  CONCLUSIONS
  In contrast to anti-microbial Abs, we found only minor changes in serum anti-food Ab levels in specific subgroups of IBD patients. Fecal Ab levels towards microbial and food antigens show distinct patterns in controls, CD and UC patients.
authors.affiliation: Department of Internal Medicine III, University Hospital Aachen, RWTH University, Aachen, Germany.
authors.forename: Lisa
authors.initials: L
authors.lastname: Frehn
authors.affiliation: Department of Internal Medicine III, University Hospital Aachen, RWTH University, Aachen, Germany.
authors.forename: Anke
authors.initials: A
authors.lastname: Jansen
authors.affiliation: Department of Internal Medicine III, University Hospital Aachen, RWTH University, Aachen, Germany.
authors.forename: Eveline
authors.initials: E
authors.lastname: Bennek
authors.affiliation: Department of Internal Medicine III, University Hospital Aachen, RWTH University, Aachen, Germany.
authors.forename: Ana D
authors.initials: AD
authors.lastname: Mandic
authors.affiliation: Department of Internal Medicine III, University Hospital Aachen, RWTH University, Aachen, Germany.
authors.forename: Ilknur
authors.initials: I
authors.lastname: Temizel
authors.affiliation: Department of Internal Medicine III, University Hospital Aachen, RWTH University, Aachen, Germany.
authors.forename: Stefanie
authors.initials: S
authors.lastname: Tischendorf
authors.affiliation: Department of Internal Medicine III, University Hospital Aachen, RWTH University, Aachen, Germany.
authors.forename: Julien
authors.initials: J
authors.lastname: Verdier
authors.affiliation: Department of Internal Medicine III, University Hospital Aachen, RWTH University, Aachen, Germany.
authors.forename: Frank
authors.initials: F
authors.lastname: Tacke
authors.affiliation: Department of Internal Medicine III, University Hospital Aachen, RWTH University, Aachen, Germany.
authors.forename: Konrad
authors.initials: K
authors.lastname: Streetz
authors.affiliation: Department of Internal Medicine III, University Hospital Aachen, RWTH University, Aachen, Germany.
authors.forename: Christian
authors.initials: C
authors.lastname: Trautwein
authors.affiliation: Department of Internal Medicine III, University Hospital Aachen, RWTH University, Aachen, Germany.
authors.forename: Gernot
authors.initials: G
authors.lastname: Sellge
mesh_terms: D000941:Antigens / Q000276:immunology*; D016022:Case-Control Studies; D003424:Crohn Disease / Q000097:blood / Q000276:immunology; D005243:Feces / Q000382:microbiology*; D005502:Food; D006801:Humans; D007070:Immunoglobulin A / Q000097:blood*; D007074:Immunoglobulin G / Q000097:blood*; D015212:Inflammatory Bowel Diseases / Q000097:blood / Q000276:immunology* / Q000382:microbiology; D044967:Serum / Q000382:microbiology*; D014409:Tumor Necrosis Factor-alpha / Q000037:antagonists & inhibitors / Q000378:metabolism
chemical_list: D000941:Antigens; D007070:Immunoglobulin A; D007074:Immunoglobulin G; D014409:Tumor Necrosis Factor-alpha