Presence of antibodies against Helicobacter pylori and its heat-shock protein 60 in the serum of patients with Sjogren's syndrome

Objective. Helicobacter pylori infection elicits a local and systemic immun e response against bacterial antigens, including a heat-shock protein of 60 kDa (HSP60). The homology between microbial and human HSP suggests that th e immune response to bacterial HSP may play a role in the pathogenesis of a utoimmune disorders. Since gastric involvement and H, pylori have been repo rted in Sjogren's syndrome (SS), we investigated the prevalence of antibodi es against H, pylori and its specific HSP60 in sera from patients with SS. Methods. Four groups of patients were studied. Group 1, 34 patients with pr imary SS (pSS); Group 2, 19 patients with secondary SS; Group 3, 22 patient s with various autoimmune diseases and Group 4, 43 healthy controls. Serum IgG levels against HSP60 were determined by an ELISA using recombinant full length HSP60 expressed in Escherichia coli, as the antigen. To confirm the H, pylori infection, a commercial ELISA was used. Results, Out of 34 patients in Group 1, 27 (79.4%) and 30 (88.2%) had antib odies against H, pylori and its HSP60, respectively. The prevalence was sig nificantly higher than that found in Group 3 (18.2%, p < 0.0001 and 27.3%, p < 0.0001) and in Group 4 (48.8%, p < 0.005 and 37.2%, p < 0.0001) but not than that of Group 2 (48.8% and 37.2%). If the prevalence of patients eith er positive or negative for both antibodies was considered, a statistically significant difference was found between Group 1 and respectively Groups 3 and 4. Conclusion, The hypothetical role of HSP60 in the development of the immune response both in pSS and secondary SS seems strictly Linked to the prevale nce rate of H. pylori infection.