Cell mediated immunity in Yersinia arthritis

Yersinia is a facultatively intracellular microorganism, and cell-mediated immunity plays an important role in the organism's defence against it. In order to study this factor in the development of reactive arthritis, in vitro lymphocyte proliferative responses after stimulation with Yersinia, Ecoli or Klebsiella were studied. Whole blood cultures demonstrated that yersinia infection triggers a definite response. Lymphocytes of patients with reactive arthritis showed weaker responses to both Yersinia and Ecoli than those of patients who had recovered from Yersinia infection without complications. The responses to unrelated antigens and to PHA or Con A were similar in both groups. When a more sensitive method using isolated lymphocytes was applied, the same difference was demonstrable even three to five years after the infection: patients with reactive arthritis had weaker responses against Yersinia and Klebsiella than those who had recovered uneventfully from yersinia enteritis. Similar responses against the different bacteria suggest that the so-called common enteric antigens may have role in this phenomenon. The present results together with those of Granfors et al (in this issue) suggest that persons developing reactive arthritis have some primary immunological abnormalities which predispose them to complications after yersinia infection.