Factors associated with the development of reactive arthritis.

The role of the causative microorganism in the generation of reactive arthritis is decisive, but host factors are also of major importance. Patients who develop reactive arthritis after Yersinia enteritis show several interesting features in the immunological defence against Yersinia when compared to those who recover uneventfully. When all these peculiarities are taken together, they strongly indicate that in the patients developing reactive arthritis the causative microorganism enters host tissues to persist within the body for prolonged periods of time.