AB0058 DIAGNOSTIC UTILITY OF VASCULAR ULTRASOUND IN BEHÇET SYNDROME
Authors: M. Serrano Warleta, C. A. Guillén-Astete, J. Arroyo-Palomo, M. Vázquez Díaz
Journal: Annals of the Rheumatic Diseases (2024)

<h3>Background:</h3> Diagnosis of Behçet syndrome (BS) remains a challenge despite the existence of classification criteria. Recently researchers have observed that femoral venous wall thickness (VWT) in these patients is increased compared to healthy controls[1]. New diagnostic tools would allow early identification of patients with BS. <h3>Objectives:</h3> To determine the existence of differences in the wall thickness of femoral and axillary veins and arteries in patients diagnosed with BS and healthy controls and, if applicable, to identify clinical variables associated with a presumed increase in wall thickness in the group of patients. <h3>Methods:</h3> Observational, comparative, analytical, single-centre study. We included patients with diagnosis of BS according to ICBD 2013 criteria[2], of no less than one year, any cluster and under current follow-up in our centre for a period of 12 months. Patients with stents or bypass surgery were excluded. Patients with a history of DVT were not excluded. Demographically matched controls were recruited with patients with a 2:1 ratio. Those with a diagnosis of any systemic inflammatory or any vascular disease involving large-bore arteries were excluded. The VWT and the intima-media thickness (IMT) of the axillary and femoral veins and arteries were measured by ultrasound by an expert rheumatologist. Two measurements were made per location and the average value was recorded. <h3>Results:</h3> 26 patients and 50 controls were included. In the patient group the mean (standard deviation) age was 45 (13) years. The mean age at diagnosis was 32.9 (12.5) years, with a female sex ratio of 53.8% and a BMI of 25.4 (5.7). 25 patients (96.2%) had received colchicine, 8 (30.7%) prednisone and 6 (23.0%) NSAIDs drugs. In the patient-control group there were 2 (7.6%) and 13 (26%) active smokers, respectively. No statistically significant differences were found between patients and controls in terms of taking lipid-lowering treatment (11.5% vs 16% respectively). Breaking down by explored territories, statistically significant differences were found between patients and controls in the means of all except in the case of axillary arteries IMT (Table 1). In the area under the curve (AUC) determination study, a statistically significant discriminative ability was demonstrated in the femoral (AUC 0.954; 95%CI 0.892-1.000;p &lt; 0.001) and axillary vein (AUC 0.848; 95%CI 0.745-0.951;p &lt; 0.001). For femoral VWT, an average cut-off point of 0.48mm was associated with the diagnosis of BD with a sensitivity of 92.3% and a specificity of 98%. For axillary VWT, an average cut-off point of 0.36mm was associated with BD diagnosis with a sensitivity of 80.8% and a specificity of 70% (Figure 1). Linear regression analysis found that the strongest predictor of mean venous wall thickness was mean arterial IMT (Coef. Beta=0.748;B=0.800;p&lt;0.001) followed by the need for lipid-lowering treatment (Coef. Beta=0.262;B=0.128;p=0.31). <h3>Conclusion:</h3> There is a significant increase in mean VWT among patients compared to controls with similar characteristics. A mean femoral VWT value of 0.48mm and axillary VWT of 0.36mm correctly classifies patients respect to population. Although mean arterial IMT does not appear to discriminate between patients and controls, we did find statistically significant differences in the femoral territory, and it appears that its magnitude significantly predicts an increase in mean VWT. The diagnostic value of this determination is not intended to replace criteria, but it could be considered as another variable in favour of the diagnosis in situations of reasonable doubt. <h3>REFERENCES:</h3> [1] Alibaz-Oner, Fatma et al. "Femoral vein wall thickness measurement: A new diagnostic tool for Behçet's disease." Rheumatology (Oxford, England) vol. 60,1 (2021): 288-296. doi:10.1093/rheumatology/keaa264. [2] International Team for the Revision of the International Criteria for Behçet's Disease (ITR-ICBD). "The International Criteria for Behçet's Disease (ICBD): a collaborative study of 27 countries on the sensitivity and specificity of the new criteria." Journal of the European Academy of Dermatology and Venereology: JEADV vol. 28,3 (2014): 338-47. doi:10.1111/jdv.12107. <h3>Acknowledgements:</h3> <b>NIL.</b> <h3>Disclosure of Interests:</h3> <b>None declared.</b>