Background Recent studies have shown that ultrasound (US) assessment of disease activity in rheumatoid arthritis (RA) with associated fibromyalgia (FM) before disease-modifying antirheumatic drug (DMARD) escalation is primordial.

Objectives The purpose of this study was to identify predictive factors of detection of US synovitis and Doppler activity in RA patients with and without concomitant FM.

Methods Cross-sectional study that included patients with diagnosis of RA (ACR/EULAR.

2010 criteria) with concomitant FM (ACR 2016) and to compare it to RA patients without FM.

Demographic and RA characteristics were collected. US examination of 22 joints was blindly.

performed by a single physician. US-detected synovitis was defined and scored 0-3 using.

the OMERACT scoring system at the joint level for both grey-scale (GS) and Doppler power.

(DP). The number of joints with ≥ grade 1 GS synovitis and those with ≥ grade 1 DP were.

calculated. Multiple linear regression analysis performed, adjusting for clinical and.

demographic variables.

Results Eighty patients distributed into 40 patients in each group were recruited.

Epidemiological and RA characteristics were comparable between groups. No significant.

difference was observed between the groups in regards to mean DAS28 and the three-

variables (DAS28 V3).

Multiple linear regression showed that in RA-FM group US synovitis detection was positively.

associated with male gender (B=0.135, p=0.045) and with DAS28 V3 (B=0.454,p=0.004),

and negatively associated with the Patient global assessment (PGA) (B=-1.092,p=0.007). In.

RA group (witout FM), US synovitis was positively associated with Swollen joints count.

(SJC) (B=0.837, p=0.001). In RA-FM group, Doppler activity was positively associated with.

the DAS28 V3 (B=0.637,p=0.04) and with Physician global assessment (B=0.873,p=0.023),

negatively associated with the PGA (B=-0.642, p=0.005) while it was positively associated.

with the DAS28 (β=3.08, p=0.047) in RA group.

Conclusion Our study shows that a high DAS28 V3 seems to be significantly associated.

with active synovitis in US assessment in RA patients with comorbid FM.

REFERENCES: NIL.

Acknowledgements: NIL.

Disclosure of Interests None Declared.