Background Rheumatoid Arthritis (RA) is characterized by joint inflammation, affecting quality of life. Biologic agents allow the achievement of clinical remission and detention of structural damage. A common practice nowadays is to reduce the dose of these drugs in patients with sustained control of the disease, in order to get the best risk/benefit balance at lower cost. The impact of this practice at medium-long term is uncertain.
B mode and Power Doppler (PD) musculoskeletal ultrasound (MSUS) is more sensitive than clinical evaluation to detect joint inflammation in RA, and its usefulness to monitor therapeutic response has been recognized, but limited MSUS data is available in patients with optimized biologic therapy.
Objectives To analyze the clinical and US characteristics of RA patients treated with subcutaneous (sc) biologics at an optimized dose.
Methods Cross-sectional study in RA patients with an optimized dose of sc biologics in our centre until October 2014. Their clinical records and drug prescription data were reviewed, collecting epidemiological, clinical and therapeutic data. A MSUS was performed by a trained rheumatologist, blinded to the treatment scheme. To ensure masking some RA patients with standard dosing were also explored. The MSUS scan included a systematic evaluation on B mode and PD of wrists (radiocarpal and intercarpal joints), 1st-5th MCP and carpal extensor tendons. Both grey-scale synovitis and PD signal were graded using the semiquantitative scale of 0-3 (according to OMERACT filter ).
Results Out a total of 163 RA patients under sc biologic therapy, 34 (20.8%) were optimized. 71.4% were women, with a mean (SD) age of 61 years (±12.9) and disease duration of 14 years (±10.6), 55.9% were seropositive RA. The following agents were optimized: etanercept (70.6%), adalimumab (23.5%) and certolizumab (5.9%), used as monotherapy in 33.3% of cases. Treatment duration was 51 months (±26). Clinical remission (registered by the rheumatologist) was the main reason for optimization (81.6% of cases) and it was maintained for 20.8 months (±14). The most frequent regimens were: ETN every 10 days (45.8%) and ADA every 21 days (62.5%).
Twenty-nine patients underwent MSUS. B mode synovitis was found on 31.1% of them (6.9% with grade 3), and PD signal was present in 17.2% of cases; mostly of grade 2 (10%). Synovitis was most frequently detected in wrists and right 2-3 MCPs (Table shows data per each location). Extensor carpal tenosynovitis was found on 13.8%, with grade 1 PD signal in all cases.
Conclusions Optimization of sc biologics in RA patients was found a common practice in our unit. The MSUS has revealed that almost a third part of these patients show mild-moderate US synovitis, despite being considered in clinical remission. However, presence of PD signal was of low grade. The incorporation of MSUS may be useful to assess the convenience of dose optimization, though the repercussion of low-grade US findings in this patients is still to be clarified.
Iagnocco A,et al. Responsiveness in RA. A report from the OMERACT 11 Ultrasound workshop. J Rheumatol 2014;41:379_82.
D'Agostino MA,et al. The OMERACT Ultrasound task force-advances and priorities. J Rheumatol 2009;36:1829_32
Disclosure of Interest None declared