Background/Purpose: Recent studies suggested a disconnect between disease activity and radiographic damage in rheumatoid arthritis (RA) patients treated with more aggressive treatment (1). Therefore, the aim of this retrospective study was to examine the longitudinal association between disease activity and radiographic damage in a real world cohort of consecutive patients with early RA treated according to treat-to-target (T2T) of remission step-up therapy.

Methods: Baseline to 3-year follow-up data were used from patients with early RA (79% fulfilling ACR 1987 criteria) included in the DREAM remission induction cohort (2). Patients were treated according to protocolized T2T, aimed at 28-joint disease activity score-erythrocyte sedimentation rate (DAS28-ESR) <2.6. Disease activity assessments were performed every 3 months; X-rays of the hand and feet were assessed at baseline and after 0.5, 1, 2 and 3 years of treatment and scored using modified Sharp/van der Heijde scoring (SHS). Between and within-person relations between time-integrated disease activity scores (DAS28-ESR and CRP) and radiographic change scores over time were examined using Pearson correlations.

Results: 229 patients (63.3% female, mean age 57.5 years, baseline median symptom duration 13 weeks) with at least two radiographic assessments in the first 3 years were available for analysis. At the between-patient level, time-integrated DAS28-ESR scores were not significantly correlated with progression at the 6 month (r=0.06) and 2-year follow-up (r=0.11) and only weakly at the 1-year (r=0.17, P<0.05) and 3-year follow-up (r=0.21, P<0.05). Within individual patients, however, a different but fairly linear relationship between disease activity and progression existed over time (Figure). Individual slopes of the relationship between disease activity and progression were significantly correlated at each time point (Table) and the slope of the first 6 months was moderately significantly associated with this slope at later time points. Analyses using CRP showed similar results.

Conclusion: In early RA patients treated according to T2T, radiographic progression appears to be an individually determined disease process, driven by factors other than consistent high disease activity. Within individual patients, the association between disease activity and radiographic damage during the first 6 months in individuals seems to be a good indicator for the progression and its association with disease activity in later years.

References

1. Ann Rheum Dis. 2013;72(2):307–8.

2. Arthritis Rheum. 2011;63(10):2865–72.