title: Gliadin IgG antibodies and circulating immune complexes.
abstract: OBJECTIVE
  Circulating immune complexes (CICs) in blood are associated with autoimmune-diseases such as systemic lupus erythematosus, immune complex glomerulonephritis, rheumatoid arthritis and vasculitis. However, slightly increased serum concentrations of such CICs are sometimes also found in healthy individuals. The objective of the current study was to assess whether food antigens could play a role in the formation of CICs.
  
  
  METHODS
  A total of 352 (265 F, 87 M), so far, healthy individuals were tested for CICs containing C1q and immunoglobulin G (IgG) as well as for gliadin IgG antibodies using the ELISA technique. Additionally, fructose and lactose malabsorption was assessed using hydrogen breath tests.
  
  
  RESULTS
  In our study, 15.3% (54/352) of the patients presented with elevated CIC concentrations (above 50 microg/ml) and 6.5% (23/352) of the study population were positive for gliadin IgG antibodies (above 20 U/ml). CIC concentration levels were significantly higher in the group with elevated gliadin IgG antibodies (CIC median: 49.0 microg/ml) compared with the group with normal levels of gliadin IgG antibodies (CIC median: 30.0 microg/ml; Mann-Whitney U-test, U=1992; p <0.001). As expected, there was no difference in CIC concentrations (Mann-Whitney U-test, U=6106; p=0.783) and gliadin IgG (Mann-Whitney U-test, U=3761; p=0.411) between patients in the fructose or lactose malabsorber groups and the subjects without malabsorption.
  
  
  CONCLUSIONS
  The results of this study indicate that certain food antigens (e.g. gluten) could play a role in the formation of CICs. An association between CICs and fructose or lactose malabsorption seems to be improbable.
authors.affiliation: Department of Clinical Nutrition, Medical University of Innsbruck, Austria.
authors.forename: Alexander
authors.initials: A
authors.lastname: Eisenmann
authors.forename: Christian
authors.initials: C
authors.lastname: Murr
authors.forename: Dietmar
authors.initials: D
authors.lastname: Fuchs
authors.forename: Maximilian
authors.initials: M
authors.lastname: Ledochowski
mesh_terms: D000328:Adult; D000936:Antigen-Antibody Complex / Q000097:blood* / Q000276:immunology; D001323:Autoantibodies / Q000097:blood* / Q000276:immunology; D005260:Female; D005903:Gliadin / Q000276:immunology*; D005983:Glutens / Q000276:immunology*; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood* / Q000276:immunology; D008297:Male; D008875:Middle Aged
chemical_list: D000936:Antigen-Antibody Complex; D001323:Autoantibodies; D007074:Immunoglobulin G; D005983:Glutens; D005903:Gliadin