PATTERNS OF RADIOLOGICAL PROGRESSION IN EARLY RHEUMATOID-ARTHRITIS - RESULTS OF AN 8 YEAR PROSPECTIVE-STUDY

Objective. To describe the course of radiological progression in a coh ort of 126 patients presenting with early nonerosive rheumatoid arthri tis (RA). Methods. Criteria for recruitment to the study were fulfillm ent of the 1958 American Rheumatism Association criteria, absence of e rosive disease at presentation and duration of symptoms less than 3 ye ars. Radiographs of hands and feet at 0, 1, 2, 5, and 8 years were ava ilable on 114 patients and were scored by Sharp's method for erosion ( ERO) and joint space narrowing (JSN). Eighty-six patients were typed f or the RA susceptibility shared HLA-DR epitope. Results, The feet show ed greatest initial radiological progression, but tended to reach an e arlier and lower plateau. ERO progressed more rapidly than JSN in the first 2 years, but in parallel thereafter. The relative proportion of ERO:JSN varied, 1:1 for the wrists, 4:1 for the proximal interphalange al joints. Thirty-eight percent of joints were eroded at 2 years, 63% at 8 years. Four patterns of radiological progression were identified: flat or nonerosive disease in 29 patients, linear in 51, lag in 13, a nd plateau in 19 (irregular in 2). Changes in the rate of radiological progression were reflected by the time-integrated C-reactive protein over the same period. Rheumatoid factor titer was higher in the progre ssive groups compared to the flat group (p = 0.01). The RA susceptibil ity shared HLA-DR epitope was more frequent in the linear compared to the flat group (p = 0.03). Conclusion. A large proportion of joints be come eroded in the first 2 years of early RA. The subsequent course of radiological progression is highly variable and cannot be easily expl ained by any single model.