The Role of Musculoskeletal Ultrasound in Biologic Drug Tapering and Relapse Monitoring: Findings from a One-Year Prospective Study in a Cohort of Rheumatoid Arthritis Patients in Sustained Clinical Remission.

Objectives: To assess the role of musculoskeletal ultrasound (MSUS) in selecting patients with rheumatoid arthritis (RA) in sustained clinical remission, suitable for tapering of biologic therapy (BT), and monitoring for a subclinical relapse. Methods: In this prospective study, seventy-eight patients with RA in sustained Disease Activity for twenty-eight joints (DAS28) clinical remission underwent ultrasound (US) examination of twenty-two joints (bilaterally wrists and metacarpophalangeal and proximal interphalangeal joints). US assessment was performed on gray scale ultrasound (GSUS) and power Doppler US (PDUS) to select patients in imaging remission, defined as a total PD score of synovitis = 0. Group 1 consisted of patients in clinical and imaging remission, in which tapering of BT was done through spacing of the Tumour Necrosis Factor Alpha (TNF-α) blocker. Group 2 consisted of patients only in clinical remission (PDUS > 0), who continued standard therapy. Clinical and US assessment was done at months 6 and 12, and the rate of a clinical (defined as DAS28 ≥ 2.6) and an US relapse (PDUS score ≥ 1) was recorded. Results: Thirty-eight patients were in clinical and US remission (group 1) and forty patients only in clinical remission (group 2). At month 6, 26% of patients in group 1 and 10% in group 2 experienced a clinical and an US relapse, whereas 20% and 15% of them, respectively, only an US relapse. At month 12, 26% of patients in group 1 and 20% of patients in group 2 experienced a clinical and an US relapse, whereas 35% and 22% of them, respectively, only an US relapse. Conclusions: Real-world data show that MSUS is a useful tool to identify RA patients in sustained clinical remission appropriate for BT tapering. US monitoring could predict a clinical relapse and the need to re-escalate treatment in patients with subclinical US relapse during BT tapering.