Erosion-free rheumatoid arthritis: clinical and conceptional implications-a BARFOT study

Abstract

Background: Bone erosions may appear early or later during rheumatoid arthritis (RA), causing joint damage and functional impairment. However, in some patients erosions do not occur, even after several years of disease. This study evaluates the prevalence, clinical relevance and possible predictors of erosion-free RA.

Methods: Six hundred and eight patients from an early RA cohort (BARFOT) having radiographs of hands and feet at inclusion and after 1, 2, 5 and 8 years were studied. Clinical and functional assessments were performed on all these time-points.

Results: In all, 144 patients (24%) did not develop erosions up to 8 years follow-up (Never erosive group), while 464 patients (76%) had erosions on one or more assessments (Ever erosive group). At diagnosis, the patients in the Never erosive group were significantly younger, satisfied fewer ACR criteria, and were less frequently RF- and/or anti-CCP- positive compared with those in the Ever erosive group. The Never erosive patients had consistently more tender joints, lower erythrocyte sedimentation rate (ESR) and, from two years and onwards, fewer swollen joints. Absence of rheumatoid factor (RF) and/or anti-CCP were strong independent predictors for erosion-free disease. The erosion-free patients were less frequently treated with DMARDs and/or prednisolone.

Conclusions: One-quarter of the patients was erosion-free during eight years in this early RA cohort. Erosion-free patients had a less severe disease course as to disease activity and were more often seronegative compared with those with erosive disease. The results suggest that non-erosive RA represents a milder form of RA.

Keywords: ACR criteria; Disease progress; Erosion-free; Erosions; Prognosis; Radiography; Rheumatoid arthritis.

Fig. 1

The graphs show the disease course in the Never and Ever erosive groups from baseline to eight years regarding 28-joints Disease Activity Score (DAS28) (A), number of tender joints (B), number of swollen joints (C), erythrocyte sedimentation rate (D), visual analogue scale (VAS) patient global assessment (PatGA) (E), VAS pain (F) and Health assessment questionnaire (HAQ) (G). On the Y-axis we present the mean values of the measured data

Fig. 2

The time to first erosion in the Ever erosive patients (n = 464). Percent of patients with early onset of erosions (at baseline or one year) and with late onset (at two, five or eight years)