Background/Purpose:

Treat-to-target is a key principle in rheumatoid arthritis. Composite scores such as the DAS-28 help to monitor disease activity and response to therapy. However, in patients without clinical activity, ultrasound examination may reveal subclinical synovitis. While some findings have prognostic relevance, little is known about the relevance of borderline (grade 1) ultrasound findings in asymptomatic joints of patients with good response to therapy. This study was undertaken to give a sonographic analysis of subclinical synovitis in this subset of RA patients.

Methods:

Patients with newly diagnosed RA were included. At baseline, patients were assessed by clinical examination and ultrasound. Ultrasound was performed with grey scale (GSUS) and power Doppler (PDUS) in the metacarpophalangeal, proximal interphalangeal, metatarsophalangeal and wrist joints, using the dorsal approach in each joint. Synovitic findings in GSUS and PDUS were graded semiquantitatively from 0 to 3 as specified before. After the initial assessment, patients were treated with anti-rheumatic drugs according to national guidelines and were seen on a regular outpatient basis. Clinical and sonographic reevaluation together with assessment of EULAR responses was performed at month 6.  

Results:

Sofar, 40 patients were included into this ongoing study. Patients’ characteristics are consistent with a typical RA cohort. By month 6, good, moderate and no EULAR responses were reached by 65.7%, 25.7% and 8.6% of the patients, respectively. In the group with good EULAR response, 7.2% of the joints had clinical synovitis, while 92.8% of the joints were asymptomatic. In the asymptomatic group, ultrasound detected subclinical synovitis in 11.1% in GSUS and in 3.8% in PDUS with significant differences for both modalities in comparison to the clinically apparent group. The sonographic findings in the subclinical group could be classified as grade 1, grade 2 and grade 3 in 78.9%, 19.7% and 1.3% in GSUS, and in 76.9%, 23.0% and 0% in PDUS. Grade 1 GSUS and PDUS findings were found significantly more often in the subclinical group, while non-grade 1, i.e. grade 2 and grade 3 GSUS and PDUS findings were significantly more prevalent in the clinically apparent group.

Conclusion:

More than 90% of the joints were asymptomatic in the group with good response. Ultrasound of these joints revealed subclinical synovitis in 11.1% in GSUS and in 3.8% in PDUS. Concerning the pattern of ultrasound findings, grade 1 findings were most prevalent in both modalities and were found significantly more often than in the clinically apparent group. Of note, grade 1 GSUS findings are also found in healthy individuals and hence, the clinical relevance seems to be questionable. While persistent PDUS activity in general has been linked to clinical relapses in asymptomatic patients, the specific relevance of grade 1 PDUS findings needs to be further clarified. Taken together, these data indicate that the relevance of subclinical synovitis may be overestimated in asymptomatic joints of patients with a good clinical treatment response. In this situation ultrasound seems to add little to the clinical overall impression. Further analysis is underway to clarify the role of grade 1 PDUS findings.

---

« Back to 2012 ACR/ARHP Annual Meeting

ACR Meeting Abstracts - https://acrabstracts.org/abstract/assessing-subclinical-synovitis-in-rheumatoid-arthritis-arthrosonographic-findings-in-patients-with-good-response-to-therapy/