Background Ultrasonography (US) is an imaging tool able to evaluate patients affected by inflammatory arthropathies, thanks to its ability in detecting inflammatory and structural abnormalities and to its higher sensitivity compared with clinical evaluation. Several studies evaluated the role of US in diagnosis and follow-up of patients with Rheumatoid Arthritis (RA), mainly focusing on joint synovitis. Few studies evaluated specifically the inflammatory tendon involvement.
Objectives We aimed to evaluate the prevalence and clinical significance of tenosynovitis detected by US in patients with RA with moderate/high disease activity naïve to biological treatment.
Methods In this cross-sectional study, we enrolled patients affected by RA (1987 ACR criteria) candidate to start biological treatment. The patients underwent clinical, laboratory and ultrasonographic evaluation. Disease activity was evaluated using 28-joint DAS. Health assessment questionnaire (HAQ) was also administered.
Bilateral high-resolution US at the level of flexor tendons of II and III finger and extensor tendon compartments at wrist level was performed. Moreover, II metacarpophalangeal (MCP), III MCP and radiocarpal (RC) joints were evaluated. Tenosynovitis, joint effusion (JE), synovial hypertrophy (SH) and PD were evaluated according to OMERACT definitions. All the lesions were graded according to a semi-quantitative scale ranging from 0 to 3 (0=absent, 1=mild, 2=moderate and 3=severe). Then, US inflammatory scores, calculated by adding the values given to each elementary lesion, were elaborated for every single joint or tendon. Finally, a global score was obtained by adding together the scores from each joint and tendon separately. Moreover, PD both at joint and tendon levels was evaluated also by using a dichotomous score (presence/absence).
Results Forty-eight patients affected by RA were evaluated. In table the main clinical, laboratory and ultrasonographic features are summarized. Tenosynovitis was observed in 30/48 (62.5%) patients. Synovitis and erosions were identified in all patients. The presence of tenosynovitis was associated with high disease activity (defined as DAS28>5.1, P=0.015), with the positivity for rheumatoid factor (P=0.025) and with the presence of anti-CCP (P=0.023). Moreover, a positive correlation between the synovitis score and, respectively, the erosion score (P<0.0001, r=0.582), the DAS28 values (P=0.006, r=0.41) and rheumatoid factor ((P=0.001, r=0.37) was observed. The presence of erosions correlated also with the joint PD score (P<0.0001, r=0.507) and with disease duration (P=0.04, r=0.35).
Conclusions We demonstrated that US-detected tenosynovitis is a relevant manifestation in RA patients. Indeed, it is associated with serologically positive patients and with higher disease activity. PD was confirmed to correlate with a more severe bone damage in terms of erosions observed by US.
Disclosure of Interest None declared