FRI0628 DIAGNOSTIC VALUE OF OPTICAL SPECTRAL TRANSMISSION IN PATIENTS WITH RHEUMATOID ARTHRITIS: CORRELATIONS WITH DISEASE ACTIVITY, EPIDEMIOLOGIC AND ANTHROPOMETRIC PARAMETERS
Authors: Konstantinos Triantafyllias, Caroline Heller, Michele De Blasi, Peter Galle, Andreas Schwarting
Journal: Annals of the Rheumatic Diseases (2019)

<h3>Background</h3> Valid assessment of disease activity leads to improvement of long-term outcomes in patients with rheumatoid arthritis (RA) (1). Clinical disease activity assessment tools such as the Disease Activity Score 28 (DAS28) are partially subjective and do not always depict the real inflammatory burden. Ultrasound (US) and Hand-MRI are important diagnostic modalities which can nevertheless be time consuming (US, MRI), expensive (MRI) or usually performed unilaterally (MRI). Thus, further diagnostic tools are needed. Optical spectral transmission (OST) is a new modality able to assess the blood-specific absorption of light transmitted through a tissue promising quantification of inflammation in the finger and wrist joints of RA patients (commercial device: HandScan - Hemics, The Netherlands)(2). <h3>Objectives</h3> To examine the diagnostic value of OST in detecting inflammation in patients with RA and to evaluate for the first time its relationship with disease activity markers and various anthropometric and epidemiologic patient characteristics. <h3>Methods</h3> OST-Measurements were performed in 168 RA-patients and 114 healthy controls. The difference between OST in the two groups was statistically examined and subsequently controlled for the effect of possible confounding factors. Moreover, association of OST with clinical, ultrasound and serological RA activity markers was evaluated. Finally, relationship of OST with radiographic joint pathology and various anthropometric and epidemiologic parameters (BMI, hand-size, gender, age) was examined. <h3>Results</h3> OST was significantly higher in the patients group in comparison to the control group, even after adjustment for the effects of various confounding factors (<i>p<sub>adj</sub>&lt;</i><i>0.001</i>). OST correlated in both groups significantly with gender, hand-size and Body Mass Index (<i>all; p&lt;</i><i>0.001</i>). In the patients group, OST correlated significantly with all examined disease activity markers (DAS28, ESR, counts of tender/swollen joints, VAS; all, <i>p<sub>adj</sub>&lt;</i><i>0.05</i>) and with age (<i>p&lt;</i><i>0.001</i>). OST showed significant correlations with a power Doppler ultrasound-Score (<i>p=</i><i>0.001</i>) and with a combined power Doppler/grey scale ultrasound-Score (<i>p&lt;</i><i>0.001</i>). Finally, receiver operating characteristic showed the best OST performance at the level of metacarpophalangeal joints level (AUC=0.75; 95%CI=0.686-0.821). <h3>Conclusion</h3> OST correlated with serological and clinical disease activity markers as well as with different anthropometric and epidemiological parameters of RA-patients. OST could therefore prove to be a good non-interventional complementary tool to assess RA activity next to well established diagnostic methods such as the US or MRI. <h3>References</h3> [1] Katchamart W, et al. Systematic monitoring of disease activity using an outcome measure improves outcomes in rheumatoid arthritis. J Rheumatol2010;37:1411–1415. [2] Onna M Van, et al. Assessment of disease activity in patients with rheumatoid arthritis using optical spectral transmission measurements, a non-invasive imaging technique. Ann Rheum Dis2016;75:511–518. <h3>Disclosure of Interests</h3> Konstantinos Triantafyllias: None declared, Caroline Heller : None declared, Michele De Blasi : None declared, Peter Galle : None declared, Andreas Schwarting Grant/research support from: GSK, Pfizer, AbbVie, Novartis, Roche, Speakers bureau: GSK, Novartis