Reactive arthritis: a favorable 2 year course and outcome, independent of triggering agent and HLA-B27

To study the 2 year course and clinical and radiological outcome of reactive arthritis and to identify possible outcome predictors.

Patients with chlamydia induced arthritis (n = 25) and arthritis induced by enterobacteria (n = 27), all derived from a 2-year epidemiological study on reactive arthritis (ReA) and possible ReA, were followed prospectively with clinical, laboratory and radiographic examinations.

After one year, 40% of patients with chlamydia induced arthritis and 20% of those with enteroarthritis still had clinical signs of arthritis. After 2 years, 100 and 95%, respectively, had recovered. At that time, one patient with enteroarthritis had developed radiographic abnormalities exceeding grade I in peripheral joints. None developed bilateral sacroiliitis during the course. The duration of ReA was found to be independent of the triggering agent, sex, age, duration of arthritis prior to entry, pain, index of active joints, CRP and the presence of HLA-B27.

Early recognition and elimination of the triggering microbe seems important for the arthritis outcome in ReA. The results do not support the hypothesis that the presence of HLA-B27 heralds a more serious disease course or less favorable outcome, nor that the type of triggering agent predicts the outcome.