Autoantibody levels in blood of <i>H. pylori</i>-infected patients with chronic gastritis

Helicobacter pylori (H. pylori) increases the risk of diseases associated with mucous membrane inflammation of gastrointestinal tract, in particular, gastritis, stomach ulcers, and duodenal ulcers. It may also induce a chronic immune response, causing damage to the mucous membrane and development of these diseases. In addition, the role of H. pylori in the initiation of a wide range of autoimmune diseases is discussed. The aim of this study was to assess the level of autoantibodies – markers of various autoimmune diseases in the blood of H. pylori-infected patients with chronic gastritis. We used samples of whole peripheral blood from 267 primary patients with chronic gastritis in the acute stage. The presence of H. pylori in gastric juice from patients was determined using real-time PCR. The level of autoantibodies to double-stranded and single-stranded DNA, autoantibodies to thyroglobulin, thyroid peroxidase, concentration of rheumatoid factor, IgG autoantibodies to the cyclic citrullinated peptide, IgM and IgG autoantibodies to beta(2)-glycoprotein were determined by the enzyme immunoassay. The average level of rheumatoid factor in blood serum was similar for H. pylori-infected and non-infected patients, and did not exceed the normal values. The level of antibodies to cyclic citrullinated peptide, one of the sensitive markers of rheumatoid arthritis, was increased in all patients, being, however, significantly lower in H. pylori-infected patients compared with non-infected persons. Autoantibodies to thyroglobulin, thyroid peroxidase are considered classic markers of autoimmune diseases of the thyroid gland. In blood of H. pylori-infected patients we have found an increased concentration of autoantibodies to thyroglobulin and thyroid peroxidase in comparison with non-infected ones, but the average level of these antibodies did not exceed the normal range. Any differences in the levels of systemic lupus erythematosus serological markers, i.e., autoantibodies to double-stranded and single-stranded DNA, were found between H. pylori-infected and non-infected patients. The levels of thrombosis risk marker in patients with systemic lupus erythematosus (IgG and IgM autoantibodies to beta(2)-glycoprotein) were also within the normal ranges. However, in H. pylori-infected patients, it even turned out to be statistically significantly lower than in non-infected ones. Thus, no data have been obtained on increased levels of the tested markers of autoimmune pathology in blood of H. pylori-infected patients with chronic gastritis at the acute stage. However, this does not allow us to make an unambiguous conclusion that the influence of H. pylori does not affect the development of immunological changes associated with autoimmune diseases