Immunity markers in patients with Helicobacter pylori infection: effect of eradication

BACKGROUND: Helicobacter pylori is a microorganism able to stimulate a robust inflammatory and systemic immune response. AIM: 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. PATIENTS AND 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.