POS0888 NORMAL PERCENTILE REFERENCE CURVES FOR SKIN ULTRASOUND THICKNESS AND STIFFNESS AT RODNAN SITES

Background Skin involvement is a hallmark of systemic sclerosis and an important marker disease activity, severity prognosis. [1] The modified Rodnan skin score (mRSS), the current gold standard for evaluation in SSc, both clinical trials practice, has several limitations. [2] This highlights need more sensitive objective measures involvement, not only support development new treatments, but also to facilitate earlier diagnosis SSc. Normal reference curves ultrasound parameters, considering relevant influential factors seem pivotal importance fully exploit potential these techniques as reliable tools diagnostic follow-up purposes. Objectives Our primary was establish preliminary normal dermal thickness stiffness, 17 sites, effect gender age on measures. As exploratory objective, we investigated body mass index menopause Methods A cross-sectional study conducted involving 140 healthy volunteers, aged 20-79 years. Recruitment stratified (10-year categories) guarantee balanced distribution sample. participants were excluded if they had any following conditions: (1) or connective tissue rheumatic inflamma- tory disease, (2) history insulin treated diabetes, (3) anticancer chemo/radiotherapy treat- ments, (4) exposure organic solvents, (5) past glucocorticoid treatment than 4 months (6) recent (<4 weeks) with glucocorticoids, regardless dose, indication timing. Ultrasound stiffness assessed by high-frequency (18MHz) shear-wave elastography (9MHz), respectively, at sites. All performed morning (between 9:00 13:00 hours) same room stable temperature. Outcomes evaluated through mixed linear model, univariate, multivariate regressions. derived each site, females males (Example Figure 1). An online calculator percentiles developed. radar chart showing values percentile site automatically drawn, allowing clinician export results obtained. Results total caucasian participants, i.e., 80 females, mean (SD) 47.2 (16.0) years; and, 60 males, 49.5 (17.3) years included. higher all sites (except chest ultrasound-dermal thickness). Age significant impact measures, some Gender (97.5 th , 95 75 50 25 5 2.5 ) plotted site. Conclusion are strongly associated imposing gender- age-specific values. promising refine sensitivity time- drug-induced changes. These provided basis future cooperative work strengthen its evidence-basis, representativeness refinement regarding potentially factors. 1. : curves. (A) Face; (B) Upper arm; (C) Forearm; (D) Hand; (E) Finger; (F) Foot. References [1]doi:10.1038/nrdp.2015.2; [2]doi:10.5301/jsrd.5000231; [3]doi:10.1002/acr.2359 Acknowledgements: NIL. Disclosure Interests None Declared.