Background Correct assessment of response to biologics in rheumatoid arthritis is extremely important regarding future patient management. There is still an open debate about parameters used to better classify the activity of the disease.
Objectives To correlate clinical evaluation with disease activity (SDAI, DAS28) and ultrasound (US) parameters in rheumatoid arthritis (RA) patients on stable biologic treatment.
Methods 106 consecutive RA patients on stable biologic treatment for more than 6 months were evaluated. Clinical and US evaluation were performed by two independent assessors, the same day as all laboratory tests. The scanning technique and the settings of the machine (ESAOTE MY LAB70, 15MHz linear probe) were the same for all patients. Examinations were perform by a trained ultrasonografer blinded to all clinical evaluations. US of both hands (dorsal wrist, 2nd to 5th volar metacarpophalangeal and 2nd to 4th volar proximal interphalangeal) was done. All patients were separated in two groups according to calculated SDAI (Simplified Disease Activity Index), patients heaving a value <3.3 being included in remission group and those with higher in active disease group.
Results 84% were females, mean age 58.72 (11.49) years, mean disease duration 13.48 (7.4) years. 49.1% (52) patients were treated with rituximab, 27.35% (29) with etanercept,19.9% (19) with adalimumab, 9.33% (9) with infliximab and 87.7% had a DMARD associated to the biologic. No significant statistical difference was found between clinical, paraclinical and US parameters (active synovitis score included, p=0.994, r=0.001) when patients were assessed comparing the biologic used. Mean DAS28 ESR was 3.14, with 36.8% of patients being on remission. Mean cohort SDAI was 7.98 (8.10) and 27.4% (29) of subjects were in remission. We found a significant statistical difference between active disease and remission regarding number of PD (Power Doppler) joints, total PD score, but no between total GS (Grey Scale) joint number and total GS score (see table). Even if 51.72% of the patients classified as being in SDAI remission had active synovitis on US, there was a significant statistical difference (p=0.004) between them and those with active disease (80.51%). Regarding DAS28 remission, 56.41% of patients had active synovitis, as compared to 82.08% in DAS28 active patients (p=0.004).
Conclusions Even if more than half of patients found in DAS28 or SDAI remission could have active synovitis on US, there is a statistical significant difference between them and those with active disease. Total PD score and PD joint number, but not total GS score or GS joint number, correlates with SDAI remission. Nevertheless there is still discordance between clinical and US evaluation.
Acknowledgements This paper is partially supported by the Sectoral Operational Programme Human Resources Development, financed from the European Social Found POSDRU/159/1.5/S/137390.
Disclosure of Interest None declared