Immunodominant region of Actinobacillus actinomycetemcomitans 40-kilodalton heat shock protein in patients with rheumatoid arthritis

Bacterial heat shock proteins have been implicated in the pathogenesis of s everal diseases, and the immunological relationship between rheumatoid arth ritis (RA) and Escherichia coli DnaJ has been reported. Since there are sim ilarities in the tissue destruction process of RA and periodontitis, we exa mined the reactivities of antibodies in sera from RA patients to the DnaJ p rotein from Actinobacillus actinomycetemcomitans. An enzyme-linked immunoso rbent assay showed that IgG titers to the N-terminal conservative region of the DnaJ are significantly higher in RA patients compared with the healthy controls (p < 0.05). Furthermore, we examined IgG titers of disease contro ls to determine the specificity of the immune responses to this region in R A patients. The difference between RA and infectious disease patients was a lso significant (p < 0.05). These results suggest that the N-terminal regio n of DnaJ from A. actinomycetemcomitans may contribute to the etiologic ana lysis of RA.