Background Ultrasound (US) (grey scale (GS) and power Doppler (PD)) is a sensitive tool for detection of tenosynovitis in patients with rheumatoid arthritis (RA). The extensor carpi ulnaris (ECU) and tibialis posterior (TP) tendons have previously been shown to be frequently inflamed in RA patients. Even so, only few of the US joint scores include these tendons in disease assessments.
Objectives To explore the frequency of inflammatory involvement of ECU and TP tendons in patients with established RA and study their response to biologic treatment.
Methods A total of 157 patients (83% women, 78% anti-CCP positive, mean (SD) age 52.4 (12.1) years with 11.2 (9.0) years of disease activity) were included. They were assessed at baseline when starting biologic treatment (infliximab (n=16); etanercept (n=59); adalimumab (n=8); certolizumab (n=13); golimumab (n=8); rituximab (n=37); tocilizumab (n=12); abatacept (n=4)) and after 1, 2, 3, 6 and 12 months with US, clinical (tender and swollen joints (of 28) and laboratory (ESR and CRP)) assessments. The ECU and TP tendons were examined bilaterally by US and scored semi-quantitatively 0-3 for GS and PD (one sonographer (HBH) using Siemens Antares, Excellence version, with a fixed optimal setting without upgrading during the study). The frequencies of tendon involvement at baseline as well as the sum scores of GS and PD at all examinations were calculated, and the changes in US sum scores from baseline were explored by paired samples T-test.
Results At baseline, 57% of the patients had GS pathology at least unilaterally of the ECU tendons and 50% at least unilaterally of the TP tendons, while the presence of PD activity was 33% and 36%, respectively. Only 24% of the patients had no GS tenosynovitis in the ECU/TP tendons, and the sum scores for GS assessments were 1 in 17%, 2 in 17%, 3 or 4 in 18%, 5 or 6 in 13% and 7-12 in 10%. 50% of the patients had no PD activity in the ECU/TP tendons at baseline, while sum scores of PD was 1 in 12%, 2 in 13%, 3 or 4 in 13%, 5 or 6 in 9% and 7-9 in 4%. Both the sum score for GS and PD decreased significantly from baseline during follow-up (p<0.01) and this was also found for DAS28 (ESR), CRP and assessor's global VAS (p<0.01). The table illustrates the improvements in US, clinical and laboratory assessments and the figure illustrates the sum scores of GS and PD during follow-up.
Conclusions In this large US follow-up study on patients with established RA, tenosynovitis in ECU/TP tendons was found in three quarters of the patients, and the present study showed significant decrease in inflammation during treatment. Thus, examination of ECU and TP tendons is proposed to be included in follow-up studies with use of US on RA patients on biologic medication.
Disclosure of Interest None declared