FRI0581 Ultrasonography in the detection of joint destruction in ra patients: a comparison with conventional radiography
Authors: O. Alekseeva, A. Smirnov, S. Glukhova, A. Volkov, E. Nasonov
Journal: Annals of the Rheumatic Diseases (2018)

<h3>Background</h3> RA evolves erosive polyarthritis resulting in destructive changes in the joints. Ultrasonography (US) is used in current practice as early diagnostic modality for identification of structural damage to the articular surfaces. <h3>Objectives</h3> To compare US and radiographic assessment of hands and feet joint destruction in RA patients, and to evaluate the contribution of early US detection of damage into long-term RA outcomes. <h3>Methods</h3> 75 patients with RA, mean age 54.0,<sup>44,0; 62,0</sup> disease duration 7<sup>4; 20</sup> months, were treated with MTX and biologics according to Treat-To-Target concept. Hands and feet US were analysed before initiation of treatment and in 3, 6, 9 and 12 months after. Deepening of the bony contour &gt;2 mm in width and &gt;1 mm in depth, visualised in 2 orthogonal planes, was considered as the key US sign of destructive changes (erosions) according to OMERACT criteria. A binary scoring system (presence/absence of erosions) of the joints examined was used. Radiographs were obtained at baseline, at 12 month and 4 years, radiographic changes were assessed using Sharp/van der Heijde modified scoring method. Radiographic progression was documented based on Sharp/Van der Heijde modified score changes during the follow up. <h3>Results</h3> There was a significant correlation between the counts of joints with erosions obtained with two diagnostic methods – US and radiography. This correlation was moderate before initiation of therapy (r=0,37 ; p=0,0008), and weak – after 12 month follow up (r=0,28 p=0,016). During one year US showed increase in the count of joints with erosions (from 1 [0; 2] to 2<sup>1; 3</sup>) while radiography did not show any significant change (from 0 [0; 1] to 0 [0; 1]). Bland-Altman analysis showed statistical agreement between the results obtained by two methods. Mean difference between the two modalities before initiation of treatment was −0,42 (95% CI −0,68; −0,16), and at 12 month follow up −1,16 (95% CI −1,52; −0,80), which is comparable with actual values. We identified the relationship between the difference in variables and the count of affected joints before and 12 month after initiation of treatment (r= −0,35, r= −0,53 respectively). 8% of variables were outside 2 standard deviations at baseline, and 4% – at 12 month. Logistic regression analysis showed no relationship between annual radiological progression and US diagnosed increasing count of joints with erosions at 3, 6 and 9 months follow up. However, dynamic radiographs assessment at 4 years revealed a correlation with US diagnosed count of joints with erosions at 6 month and 9 month follow up (r=0.24, p=0.03; r=0.24, p=0.04, respectively). Quality indicator of US diagnosed count of erosions at 6 month follow up: OR=2,8 95% CI 1.05–7,5, p=0.037, with 71% sensitivity and 54% specificity; Quality indicator of US diagnosed count of erosions at 9 month follow up: OR=2,73 95% CI 1.02–7,27, p=0.041, with 64% sensitivity and 61% specificity. Quantitative assessment of the dynamics at these time periods did not show any relationship. <h3>Conclusions</h3> Therefore, our study confirms the relevance of US in assessment of bone erosions in spite of week agreement with radiography data. We found a prognostic value of US-diagnosed erosions during the first year of follow upfor long-term (4 years) clinical outcomes, and the relevance of control assessment at 6 month after initiation of treatment. <h3>Disclosure of Interest</h3> None declared