P335 Utility of Intestinal Ultrasound in Monitoring Disease Activity in Ulcerative Colitis Patients Treated with Biologics

Tomašić, V.(1);Kralj, D.(1);Bišćanin, A.(1);Ćaćić, P.(1);Ogresta, D.(1);Dorosulić, Z.(1);Hrabar, D.(1);

(1)University Hospital Centre Sestre milosrdnice, Department of Gastroenterology and Hepatology, Zagreb, Croatia;

Background

Given the invasive nature and high cost of frequent and repeated endoscopies needed to monitor UC, search for non-invasive diagnostic alternative is warranted. Intestinal ultrasound is a cost-effective, well-tolerated, non-invasive and readily available „point-of-care“ tool for the management of patients with Crohn's disease. The role and widespread use of IUS for UC is still limited. We aimed to evaluate association between UC disease activity assessed by IUS on one hand and standard clinical, biochemical, and endoscopic parameters on the other one.

Methods

A single center, noninterventional retrospective chart review of adult UC patients treated with biologics at a tertiary center was performed. Routine clinical (stool frequency score – SFS, and rectal bleeding score – RBS), biochemical (FC), endoscopic (Mayo Endoscopic Subscore - MES), and IUS parameters (bowel wall thickness - BWT and colonic wall hyperemia assessed by colour Doppler imaging - CDS) were assessed before initiating biologics. Normal distribution was assessed using Shapiro-Wilk tests. Spearman correlation coefficients were calculated and ROC analysis was carried out.

Results

Total of 44 patients (50% females, mean age 37.4 ± 14.05 years) with predominantly extensive UC (75%) were analysed. Positive correlation was observed between combination of BWT and level of CDS with SFS (rs = 0.68, p < 0.01, N = 33) as well as with RBS (rs = 0.44, p < 0.01, N = 34). Moreover FC values were in positive correlation with BWT (rs = 0.54, p < 0.01, N = 36), levels of CDS (rs = 0.66, p < 0.01, N = 33) and combination of BWT coupled with level of CDS (rs = 0.7, p < 0.01, N = 33). In case of clinical active UC (SFS 2/3 + RBS 2/3 + FC >150 mg/g) correlation coefficient between FC level and BWT coupled with level of CDS rises to rs = 0.72, p < 0.01, N = 30. Positive correlation of CDS with MES (rs = 0.65, p < 0.01, N = 16) as well as between combination of BWT + level of CDS with MES (rs = 0.6, p < 0.02, N = 16) was observed. Interestingly, positive correlation between BWT and MES didn´t reach statistical significance (rs = 0.42, p = 0.1, N = 16). The area under the curve (AUC) for the FC values and disease activity (defined as SFS 2/3 + RBS 2/3 + BWT >4 mm + presence of CDS) was 0.96 (SE: 0.03; 95% CI, 0.89–0.99, p<0.01). FC values >134 mg/g were associated with active disease (sensitivity 89.3%, specificity 87.5%).

Conclusion

Results of this study show a good correlation between IUS and clinical, biochemical and endoscopic parameters of UC disease severity. IUS as a monitoring tool can be helpful in estimation of UC disease activity and can guide daily management of patients treated with biologics.