Antibodies against Yersinia enterocolitica in patients with Reiter's syndrome.

Reiter's syndrome can be induced by several different bacteria. A frequent cause in Finland is Yersinia enterocolitica serotypes 03 and 09, but these strains are rarely found in the United States. Although this does not exclude the possibility that U.S. patients with Reiter's syndrome have been infected with Yersinia, it is more likely that they develop Reiter's syndrome as a consequence of infection by non-Yersinia arthritis-causing organisms that share certain determinants with Yersinia organisms. We used radioimmunoprecipitation and sodium dodecyl sulfate-polyacrylamide gel electrophoresis to analyze the serum antibodies against iodine 125-labeled, detergent-solubilized serotype 03 Y. enterocolitica. Our results demonstrated that most serum samples of United States subjects precipitate three to five radioactively labeled Yersinia molecules. A Yersinia antigen of 88K appeared to be of possible discriminatory value. Protein A-reacting antibodies directed against this antigen were detected in only two of twenty-five patients with rheumatoid arthritis and only seven of 44 normal control subjects, compared with 18 of 27 patients with Reiter's syndrome (p less than 0.005) and eight of 16 patients with ankylosing spondylitis (p less than 0.01). Our results indicate that, despite the relatively rare occurrence of Y. enterocolitica serotypes 03 and 09 infection in the United States, examination of the immune response to the serotype 03 Yersinia strain is a promising approach to the study of Reiter's syndrome in the United States.