Background Ultrasonography (US) has superior sensitivity in detecting the presence of synovial hypertrophy (SH) and its activity by Power Doppler (PD) in Rheumatoid Arthritis (RA). The relapse rate is nearly 50% after biologic treatment withdrawal due to disease clinical remission.
Objectives The aims of the study were to assess the US SH rate in a cohort of RA patients in clinical remission who tapered first and stopped thereafter anti-TNFα treatment and to evaluate if US characteristic (SH thickening rate) could predict any clinical relapse.
Methods 49 RA patients in clinical remission (DAS<1,6) underwent baseline US evaluation (dorsal and volar view scanning of II-III MCP and II-III PIP bilaterally, wrists, knees and II-V MTP bilaterally). At baseline, RA patients were stratified into 2 subgroups as SH+/PD- and SH+/PD+, based on US characteristics. SH+/PD- patients tapered anti-TNFα treatment (Adalimumab 40 mg/monthly or Etanercept 50 mg/2 weeks) for 3 months. After biologic tapering, RA patients who were still PD-, stopped biologic and were followed for at least 3 months, maintaining only DMARDs. Treatment modifications were not allowed during the study. Relapse rate was recorded for each patient (DDAS >1,2 from the DAS value at the time of last US assessment).
Results At the study entry, 7 (14,3%) RA patients were SH+/PD+ whereas 42 (85,7%) patients were SH+/PD- and tapered the biologic. No patients were SH-/PD-. After 3 months tapering, 13 (30,9%) RA patients showed disease relapse. RA patients who relapsed, did not differ for anti-CCP (p=0,85), IgA-RF (p=0,25) and IgM-RF (p=0,51) positivity, smoking habit (p=0,47) and biologic type (p=0,69) from RA patients who did not relapse. However, significantly higher SH thickening values in MCP and MTP at baseline characterized RA patients who relapsed after 3 months tapering, compared to RA patients who did not (0,46±0,18mm vs 0,59±0,14mm for MCP and 0,36±0,22mm vs 0,65±0,44mm for MTP; p=0,05 and p=0,01 respectively). To date, among RA patients who did not relapse after tapering, 20 (70,0%) RA patients stopped biologic. After biologic withdrawal, 4 (20,0%) RA patients showed disease relapse after 3, 6, 7 and 9 months respectively. All RA patients who relapsed had disease flare in the joint site, clinically involved at the time of the disease onset (80% in the MCP and 20,0% in the knees). RA patients who relapsed did not differ for the previous demographic and immunological parameters as well as for the biologic type (16,7% of Adalimumab treated vs 25,0% of Etanercept treated patients have disease flare;p=0,65). However, SH thickening rate in MTP was found higher in RA patients who relapsed after biologic stopping (0,66±0,42mm) than who did not (0,38±0,21mm;p=0,04). Finally, all RA patients who relapsed were newly treated with the previous biologic, following the last effective therapeutic regimen.
Conclusions US based patients selection before treatment tapering and/or stopping is a useful tool to minimize disease relapse rate. Drug free remission is a possible goal in the majority RA patients without synovial tissue activity signal, with no difference between anti-TNF-α agents.
Disclosure of Interest None declared