Background The approach to treating rheumatoid arthritis (RA) has changed over the last decade (1). Patients with disease in remission might show residual subclinical inflammation (2).
Objectives The aim of this study was to define the factors affecting ultrasonographic remission in clinical remission of patients with RA.
Methods We included a cohort of patients with RA whose disease was in remission according to Disease Activity Score 28 (DAS 28) and American College of Rheumatology/European League Against Rheumatism (ACR/EULAR) 2011 remission criteria for at least two months. Patients had to have established RA, which was defined according to the 2010 RA ACR/EULAR clasification criteria. The following clinical data were recorded at baseline: time elapsed from first clinical symptoms, time elapsed after diagnosis, presence of medication compliance and duration of clinical remission. Musculoskeletal ultrasound (US) examination evaluated the presence of active synovitis, power Doppler (PD) signal, and synovitis on the following bilateral joints: the first through the fifth metacarpophalangeal joints, the first through the fifth proximal interphalengeal joints and the radiocarpal, ulnocarpal and intercarpal compartments of the wrist.
Results A total of 64 RA patients with a mean disease duration of 79.97 months were studied. In the entire cohort of RA patients, 36% had evidence of synovial hypertrophy at least one joint on gray-scale US and 29% had increased PD signal at least one joint. 14% had evidence of tenosynovitis at least one tendon on gray-scale US and 10% had increased PD signal for tenosynovitis at least one tendon. The interobserver reliability assessment showed an exact agreement of 89% and 92% for the presence/absence of synovitis and for the PD signal, respectively. Age and synovitis, tenosynovitis total scores weakly correlated (respectively, r=0.28, p=0.02; r=0.26, p=0.03). The delay in diagnosis highly correlated with synovitis, synovitis PD signal total scores (respectively, r=0.55, p=0.000; r=0.51, p=0.001). A weak negative correlation was found between all the US variables and duration of clinical remission (respectively, r= -0.426, p=0.000; r=-0.333, p=0.007, r= -0.243, p=0.050; r=-0.247, p=0.049). There was no correlation between erythrocyte sedimentation rate, C-reactive protein level and US variables (p<0.05).
Conclusions Synovial inflammation could persist in clinical remission of patients with RA. According to our study, US detects subclinical synovitis. The most important factors that prevent ultrasonographic remission are short duration of clinical remission and delay in diagnosis.
Naredo E, Bonilla G, Gamero F, Uson J, Carmona L, Laffon A. Assessment of inflammatory activity in rheumatoid arthritis: a comparative study of clinical evaluation with grey scale and power Doppler ultrasonography. Ann Rheum Dis 2005;64:375-381.
Brown AK, Quinn MA, Karim Z, Conaghan PG, Peterfy CG, Hensor E, et al. Presence of significant synovitis in rheumatoid arthritis patients with disease-modifyingantirheumatic drug-induced clinical remission: evidence from an imaging study may explain structural progression. Arthritis Rheum. 2006 Dec;54(12): 3761-73.
Disclosure of Interest None declared