FRI0011 Ultrasonographic criteria for the diagnosis of erosive rheumatoid arthritis disease using osteoarthritic patients as controls compared to validated radiographic criteria
Authors: C. Roux, F. Gandjbakhch, A. Pierreisnard, M. Couderc, C. Lukas, R. Masri, J.-P. Sommier, I. Clerc-Urmes, C. Baumann, I. Chary-Valckenaere, D. Loeuille
Journal: Annals of the Rheumatic Diseases (2018)

<h3>Background</h3> Rheumatoid arthritis (RA) is the most prevalent chronic inflammatory joint disease<sup>1,2</sup> responsible for structural damage. Radiography (RX) is considered as the gold standard for visualising and quantifying bone lesions in RA.<sup>3</sup> Musculoskeletal ultrasound (US) is booming in clinical practice for the diagnosis of RA. US can detect more erosions than RX at the joint level, especially at an early stage of the disease.<sup>4</sup> <h3>Objectives</h3> To determine thresholds for the diagnosis of erosive RA by US in RA and osteoarthritic (OA) patients and to compare these US thresholds with RX ACR/EULAR 2013 criteria for erosive RA. <h3>Methods</h3> Patients fulfilling ACR 1987 and/or ACR/EULAR 2010 criteria for RA or hand OA criteria were prospectively included. A modified Sharp erosion score was assessed by two blinded readers and one adjudicator for discordant cases (number of eroded joints ≤three). Erosions in US were scored on six bilateral joints (MCP2–3, 5; MTP2–3, 5) with a four-grade scale to calculate total US score for erosions (USSe). <h3>Results</h3> A total of 168 patients were included: 122 RA (32 early RA &lt;2 years; 90 late RA ≥2 years); 46 OA patients. On RX: 42 RA patients (6 early; 36 late) and 5 OA patients were eroded according to ACR/EULAR 2013 criteria with sensitivity at 34.4% and specificity at 89.1%. On US, 95 RA patients (21 early; 78 late) and 12 OA patients were eroded. Considering at least two joint facets eroded or at least one joint facet eroded at grade 2 on US, sensitivities were good (68%–72.1%) and specificities excellent (89.1%–100%). Agreement between RX and US was excellent (90%–92%). US diagnosed two times more patients than RX as erosive disease in both early and late RA patients. <h3>Conclusions</h3> USSe can differentiate RA from OA in erosive disease and detect two times more patients with erosive RA than RX with excellent specificity and agreement, according to two different criteria (number of facets eroded and severity of erosion at the joint facet level). <h3>References</h3> [1] Guillemin F, et al. Prevalence of rheumatoid arthritis in France: 2001. Ann Rheum Dis2005Oct;64(10):1427–30. [2] Alamanos Y, et al. Incidence and prevalence of rheumatoid arthritis, based on the 1987 American College of Rheumatology criteria: A systematic review. Semin Arthritis Rheum2006Dec;36(3):182–8. [3] Baillet A, et al. Comparison of the efficacy of sonography, magnetic resonance imaging and conventional radiography for the detection of bone erosions in rheumatoid arthritis patients: a systematic review and meta-analysis. <i>Rheumatol Oxf Engl</i>2011Jun;50(6):1137–47. [4] Wakefield RJ, et al. The value of sonography in the detection of bone erosions in patients with rheumatoid arthritis: a comparison with conventional radiography. Arthritis Rheum2000Dec;43(12):2762–70. <h3>Disclosure of Interest</h3> None declared