Based on the results of our exercise, the OMERACT US definitions for the identification of CPPD demonstrated to be reliable when applied to the TFC and AC. Other sites reached good kappa values in the web-based exercise but failed to achieve good reproducibility at the patient-based exercise, meaning the scanning method must be further refined.

The burden of entheseal sonographic changes was significantly higher in SLE patients than in healthy subjects, especially as regards active inflammation. The presence of power Doppler signal at the enthesis may represent a potential biomarker of SLE disease activity.

Background Musculoskeletal involvement is extremely common in patients with systemic lupus erythematosus (SLE). Continuing the research initiated in patients with inflammatory arthritis, recent studies have shown the potential role of musculoskeletal ultrasound (MSUS) in the evaluation of clinical and subclinical lupus synovitis. The inflammatory process in SLE is traditionally considered to be localized at synovial tissue areas while enthesis is not included among the possible targets of the disease. Patients and methods Entheses included in the Glasgow Ultrasound Enthesitis Scoring System were scanned in a cohort of 20 SLE patients serving as disease controls in an MSUS study aimed at assessing enthesitis in patients with psoriatic arthritis. We describe in detail four cases with unexpected and unequivocal expressions of MSUS enthesitis according to the OMERACT definition. Three out of four patients had no predisposing factors for enthesopathy. Case no. 2 was treated with a variable-dose prednisone regimen. Results In the four cases MSUS examination revealed relevant grey-scale and power Doppler abnormalities at the entheseal level, most commonly at the distal insertion of the patellar tendon. Signs of clinical enthesitis were detected in only one patient. Conclusions This case series shows for the first time the presence of clearly evident MSUS findings indicative of enthesitis in four out of 20 SLE patients (20%), raising the hypothesis that enthesis could be a missing target in the clinical evaluation of SLE patients. Our case series justifies further investigations for a better evaluation of the prevalence, characteristics and clinical relevance of entheseal involvement in SLE.

Objectives To investigate the reliability of the OMERACT ultrasound (US) Task Force definition of US enthesitis in spondyloarthritis (SpA). Methods In this web exercise, based on the evaluation of 101 images and 39 clips of the main entheses of the lower limbs, the elementary components included in the OMERACT definition of US enthesitis in SpA [hypoechoic areas, entheseal thickening, power Doppler signal (PD) at the enthesis, enthesophytes/calcifications, bone erosions] were assessed by 47 rheumatologists from 37 rheumatology centres in 15 countries. Inter and intra-observer reliability of the US components of enthesitis was calculated using Light’s kappa, Cohen’s kappa, Prevalence and Bias Adjusted Kappa (PABAK) and their 95% confidence intervals. Results Bone erosions and PD showed the highest overall inter-reliability [Light’s kappa: 0.77 (0.76–0.78), 0.72 (0.71–0.73), respectively; PABAK: 0.86 (0.86–0.87), 0.73 (0.73–0.74), respectively], followed by enthesophytes/calcifications [Light’s kappa: 0.65 (0.64–0.65), PABAK: 0.67 (0.67–0.68)]. This was moderate for entheseal thickening [Light’s kappa: 0.41 (0.41–0.42), PABAK: 0.41 (0.40–0.42)], and fair for hypoechoic areas [Light’s kappa: 0.37 (0.36–0.38); PABAK: 0.37 (0.37–0.38)]. A similar trend was observed in the intra-reliability exercise, although this was characterized by an overall higher degree of reliability for all US elementary components compared with the inter-observer evaluation. Conclusions The results of this multicentre, international, web-based study show a good reliability of the OMERACT US definition of bone erosions, PD, and enthesophytes/calcifications. The low reliability of entheseal thickening and hypoechoic areas raises questions about the opportunity to revise the definition of these two major components for the US diagnosis of enthesitis.

BackgroundIn rheumatoid arthritis (RA) the “window of opportunity” has a crucial role for better long-term outcomes.1 The ACR/EULAR remission criteria for RA are mostly represented by clinical parameters, while ultrasound (US) is not included.2 However, in early diagnosed and early treated patients, who fulfil the remission criteria, residual US modifications can be identified.3 ObjectivesThe aim of this study was to investigate whether significant US-detectable differences between early RA (ERA) patients treated for one year and healthy controls (HC) are present.MethodsWe enrolled in this cross-sectional study consecutive patients with ERA at 1 year after having initiated RA disease-modifying (DMARD) therapy and who had received treatment following RA recommendations. Only patients who had fulfilled EULAR/ACR 2010 criteria for RA4 and with symptoms duration of less than 1 year at treatment initiation were included. US exams were performed in 10 joints bilaterally (wrist, MCP II-V) by using both gray-scale and Doppler for evaluating synovitis was graded according to a semi-quantitative 4-point scale (0–3). A total US score for synovitis was calculated by adding the values recorded at each joint site. The presence of erosions was also recorded. Finally, US results obtained in patients were compared to those detected in HC.Results84 subjects were enrolled – 45 ERA patients and 39 HC. In ERA patients the mean duration of symptoms prior to diagnosis was 3.5±3.5 months. The demographic, clinical and US data are reported in table 1.Abstract SAT0672 – Table 1Demographic, clinical and US data for ERA patients and HC [n (%), mean±SD or median (IQR)]ParametersERA (n=45)HC (n=39)p Gender (Female)28 (62.2%)25 (64.1%)0.859Age56.16±19.9146.59±12.930.003VAS pain19 (10.25–30)0 (0–2)<0.001US score4 (1.5–6.5)1 (0–3)<0.001Erosions23 (51.11%)0 (0%)<0.001As expected, the values of visual analogue scale (VAS) for pain and of the total US score and the incidence of erosions were significantly higher in ERA patients than in HC. The values of the US score correlated with the presence of erosions (rs=0.427, p<0.001) as well as with the values of acute phase reactants (CRP: rs=0.539, p=0.412 and ESR: rs=0.412, p=0.005), VAS of disease activity reported by patients (rs=0.473, p≤0.001) and physician (rs=0.412, p<0.001).ConclusionsPatients with RA, who had been early diagnosed and early treated, after 1 year of tight control had still US inflammatory and erosive changes compared to HC. US assessment gives an added value to clinical evaluation in ERA, for its capacity to detect residual inflammatory abnormalities, even under optimised treatment and consequent structural lesions.References[1] van Nies JAB, et al. Ann Rheum Dis2015;74:806–812.[2] Bykerk VP1, Massarotti EM. Rheumatology2012;51(Suppl 6):vi16–20.[3] Vergara F, et al. Reumatol Clin2017Mar 18.[4] Aletaha D, et al. Arhritis Rheum2010;62:2569–2581.Disclosure of InterestNone declared