Background Remission is regarded as the best therapeutic target for patients with rheumatoid arthritis (RA). Clinical trial evidence has demonstrated a disparity between clinical status and outcome (ongoing progression of joint damage despite clinical remission (clin.remission)). Imaging techniques are capable to provide a more accurate measure of disease activity.
Objectives To assess the association of clinical and/or serological parameters of disease activity and the structural damage with ultrasound (US) defined remission in RA.
Methods Prospective analysis of 42 consecutive RA patients (pts) [median age 48 (range 39-55) years; disease duration 58 (36-96) months; disease activity score-28 (DAS28) 3.9 (2.9-5.2); 74% female; 84% “+” for rheumatoid factor (RF) and anti-citrullinated peptide antibodies (ACCP)] in therapy with anti-IL 6 receptor antibody. US was performed at baseline and after 6 months by a single operator, unaware of clinical data (“Voluson-i” (GE,USA) with array transducer (4-13MHz)). The US assessment included bilateral of the wrists and the metacarpo-phalangeal joints. Semiquantitative scoring of power Doppler (PD) signals was calculated. Definitions of sonographic remission were determined as strict imaging remission - the absence of the PD-signals (PD=0) and a less strict criterion was used to indicate low level imaging activity (PD≤1). Number of tender (TJ) and swollen joints (SJ), global assessment of disease activity by the pt (VAS-pt), C-reactive protein (CRP), erythrocyte sedimentation rate (ESR) were recorded. Clin.remission was defined when DAS28-ESR was <2.6, low disease activity state (LDA) - DAS28-ESR ≤3.2 after 6 months. Hand, feet X-ray were performed at the entry and at one year.
Results PD-signals as a sign of active disease were observed in 32 (76%) cases after 6 months. Strict imaging remission (PD=0) was found at 10 pts, a less strict criterion imaging remission (PD≤1) – at 20 cases. Clin.remission was achieved at 7 pts, LDA - at 4 pts (total n=11). Out of them 6 of 7 who fulfilled clin.remission and 8 of 11 (clin.remission or LDA) showed the positivity of PD signal (at least at one site). However, in all pts with RA in clin.remission or with LDA at 6 month we found lower baseline the USPD score (median 3 (range 2-5) vs. 5 (3-8), p=0,01), than those in pts with DAS28-ESR >3.2 at 6 month. The total Sharp Score modified by van der Heijde at one year [56 (31-98) vs. 109.5 (68.5-185) units, p<0.02] was higher in pts with PD-signals >1 (n=22) than in cases with more low imaging activity and the absence of the PD-signals (n=20). However, there was no significant difference between these markers in RA pts with strict imaging remission (PD=0). The other parameters showed no association with the presence or absence of PD-signals.
Conclusions These results confirmed that satisfying clin.remission criteria may not accurately reflect an absence of synovial inflammation. Pts with PD-signals >1 have the high risk for radiological progression. PDUS demonstrated to be useful in evaluating patients considered to be in remission.
Disclosure of Interest None Declared