Background: Antigen-specific lymphocyte proliferation of synovial fluid mononuclear cells (SF MNC) has been reported repeatedly in reactive arthritis and Lyme arthritis; however, less information is available on serial investigations of SF MNC in the same patients.
Methods: In this study, the synovial lymphocyte proliferation to Yersinia, Chlamydia, Shigella and Borrelia burgdorferi was investigated sequentially at different time points in 28 patients with reactive arthritis, undifferentiated oligoarthritis or Lyme arthritis responding to one of these bacteria.
Results: The same bacterium was always recognized in arthritis triggered by Chlamydia, Shigella or Borrelia, with much variation in the proliferative response. Only the Yersinia-specific responses changed specificity, suggesting that the proliferative response to Yersinia is non-specific in some patients.
Conclusions: Our data support the concept of a local antigen-specific T-cell response in reactive arthritis or Lyme arthritis but not the concept suggested by others that a switch to an autoimmune response takes place in long-standing disease.