title: Immunity markers in patients with Helicobacter pylori infection: effect of eradication.
abstract: BACKGROUND
  Helicobacter pylori is a microorganism able to stimulate a robust inflammatory and systemic immune response.
  
  
  OBJECTIVE
  The aim of our study was to evaluate autoimmune markers in dyspeptic patients positive for H. pylori infection compared to a control group of non-H. pylori-infected subjects. The kinetics of cryoglobulins and autoantibodies was evaluated after treatment of the infection.
  
  
  METHODS
  Dyspeptic patients with active H. pylori infection and age- and sex-matched healthy H. pylori-negative controls were studied. Markers of immunity were compared, in H. pylori-infected patients before, 6 months and 1 year after the end of therapy. Results were also compared between those with and without successful eradication therapy.
  
  
  RESULTS
  Eighty-six individual were entered (43 H. pylori-infected). H. pylori-infected patients had higher levels of IgG and/or IgA and/or IgM (22/43 versus 2/43). Circulating immune complexes and cryoglobulins were detected in patients more often than controls (p < .05 for both). Autoantibodies were observed in 13 patients (30% versus 5% in controls) and antithyroid antibodies in 12 (p < .04 versus controls). Lower levels of C3 and/or C4 complement fractions were observed in infected patients with respect to controls (7/43 versus 1/43; p = .014). After 1 year of follow-up, the markers of autoimmunity dramatically improved in patients eradicated for H. pylori infection compared to those in whom therapy failed. No patient developed a clinical autoimmune disorder.
  
  
  CONCLUSIONS
  Additional studies are necessary to ascertain the clinical significance of the modifications of autoimmune markers in patients with H. pylori infection.
authors.affiliation: Istituto di Clinica Medica, Università di Sassari, Italy. mpdore@uniss.it
authors.forename: Maria Pina
authors.initials: MP
authors.lastname: Dore
authors.forename: Laura
authors.initials: L
authors.lastname: Fastame
authors.forename: Andreina
authors.initials: A
authors.lastname: Tocco
authors.forename: Riccardo
authors.initials: R
authors.lastname: Negrini
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Delitala
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Realdi
mesh_terms: D000328:Adult; D000368:Aged; D000900:Anti-Bacterial Agents / Q000627:therapeutic use; D000936:Antigen-Antibody Complex / Q000097:blood; D001323:Autoantibodies / Q000097:blood; D015551:Autoimmunity; D015415:Biomarkers; D016022:Case-Control Studies; D003450:Cryoglobulins / Q000378:metabolism; D004415:Dyspepsia / Q000276:immunology* / Q000382:microbiology; D005260:Female; D016481:Helicobacter Infections / Q000188:drug therapy / Q000276:immunology* / Q000382:microbiology; D016480:Helicobacter pylori / Q000187:drug effects*; D006801:Humans; D007136:Immunoglobulins / Q000097:blood; D008297:Male; D008875:Middle Aged
chemical_list: D000900:Anti-Bacterial Agents; D000936:Antigen-Antibody Complex; D001323:Autoantibodies; D015415:Biomarkers; D003450:Cryoglobulins; D007136:Immunoglobulins