Background At the present time remission is the target for treatment of rheumatoid arthritis (RA). Various composite indices are available that can be used to define remission. Although the new ACR/EULAR Boolean criteria is more stringent than others, it is difficult to achieve and even more difficult to sustain this Boolean remission.
Objectives In this study we aimed to determine the differences of the ultrasonographically (US) assessed actual disease activities of the patients in remission according to different remission criteria.
Methods RA patients in clinical remission (DAS28-ESR<2.6) for at least 3 months were included to this cross-sectional study. All patients' remission status according to DAS28-ESR-3, DAS28-CRP, SDAI, CDAI and Boolean based definitions were assessed. A standard gray scale (GS) and power Doppler (PD) US examination of 28 joints (included in DAS28) for the presence of synovitis was performed by an experienced sonographer (NI) blinded to clinical data. US synovitis GS and PD signals were semiquantitatively graded from 0 to 3. Total PD and GS synovitis scores of all sites are recorded as sum scores of PD and GS, respectively.
Results A total of 88 out of 389 RA patients (22.6%) in DAS28 remission were enrolled (F/M=55/33, mean age 53.4±12.0, disease duration 10.5±6.3 years, bDMARDs 44.3%, RF/Anti-CCP positivity 72%). Of the 88 patients, 82 (93.2%), 72 (81.8%), 49 (55.7%), 40 (45.5%) and 33 (37.5%) fulfilled the DAS28-CRP, DAS28-ESR-3, SDAI, CDAI and Boolean remission criteria, respectively. PD synovitis scores which have shown to be associated with erosion development and worse functional outcome were lowest in CDAI, Boolean and SDAI remission. However despite that, those differences in US disease activity parameters (both PD and GS synovitis sum scores and percentages of patients without PD and GS signals [with both omitting and including grade 1 signals]) in remission patients according to different criteria were not statistically significant (Table 1). In comparison of US disease activity parameters of remission vs nonremission groups, only patients with Boolean and CDAI remission had significantly lower PD scores compared to their counterpart nonremission group (for both, 1 [0–4] vs 3 [1–7], P=0.015).
Conclusions US verified joint inflammation is the lowest in RA patients who are in remission according to Boolean and CDAI criteria. However, the clinical significance of this statistically nonsignificant inflammatory activity compared to other clinical remission criteria should be assessed in prospective studies. Till then, in clinical practice if Boolean remission could not be achieved, CDAI or SDAI could also be preferred as the remission target.
Disclosure of Interest None declared