Radiological progression in established rheumatoid arthritis.

Radiographic progression in established rheumatoid arthritis (RA) gives an objective measure of anatomical damage that defines the course of the disease and the longterm effects of treatment. This review defines the rate of joint damage, progression in individual joints, and predictive factors. Six longitudinal prospective studies of 103-378 RA patients followed for up to 20 years show that initially patients had less than 3% maximum possible damage, this rose to 11% maximal damage by 5 years and over 40% by 20 years. The rate of progression changed from an initial rate of 1.6% maximal progression annually to a later rate of 2.0% annually. Between 1977 and 1998 5 prospective studies of 40-147 hospital-based RA cases seen within 12 months of developing RA showed 60-73% of cases developed one or more erosions in the hands and wrists. However a community-based cohort of early RA patients reported, more recently showed 41% of 335 cases developed erosions. There are marked differences between joints. The wrists show most damage and in one series of 103 cases, by 20 years 18% of wrists were completely destroyed and only 25% were nonerosive. The same series showed ankle joints are rarely involved; at 20 years only 7 patients had major abnormalities with minor changes in 17 cases. Rheumatoid factor (RF) positivity is the dominant predictor of erosive damage. In one survey of 439 cases who presented with inflammatory polyarthritis, patients with an initial high RF had over twice the radiographic progression of seronegative cases. A further 8 studies, which enrolled 1395 patients, all show a strong link between radiolographic damage and RF status. The other key clinical predictor is disease activity indicated by surrogate measures such as the C-reactive protein (CRP) level. Suppressing disease activity judged by CRP levels not only decreases the progression of joint damage, but also may reduce new joint involvement to a greater extent than progression in already damaged joints. New potential markers of damage such as anticyclic citrullinated peptide ELISA tests may further improve the identification of those RA patients most at risk of erosive damage and, by implication, most in need of suppressive therapy.