In vitro T lymphocyte proliferative response to Yersinia enterocolitica in Reiter's syndrome. Lack of response in other HLA-B27 positive individuals.

We assessed the in vitro T lymphocyte tritiated thymidine (3HTdr) incorporation response of Reiter's patients in the United States to a serotype 3 strain of Yersinia enterocolitica. The mean 3HTdr incorporation response to the formalin killed form of this strain was 27,409 +/- 5,488 counts per minute for 14 HLA-B27 positive Reiter's patients compared with 5,414 +/- 3,490 cpm for a control group of 11 HLA-B27 positive normal individuals (P less than 0.0005). This high response in Reiter's patients was observed with the formalin killed form of Y enterocolitica serotype 3, but not with a heat killed form or a rough mutant form derived from the same bacterial strain. Further, Y enterocolitica of a different serotype (serotype 8) which is not associated with reactive arthritis failed to induce the high proliferative response observed with the serotype 3 strain. This response indicates that T lymphocytes from spontaneous Reiter's patients are capable of recognizing and proliferating to determinant(s) on the formalin killed form of Y enterocolitica serotype 3. Since this bacterium is associated with Reiter's syndrome in Europe but not the United States, these data are consistent with the possibility that our patients have previously encountered these or similar determinants through unrecognized infection with other microorganisms.