P303 Ultrasound is effective to identify mucosal healing in Crohn's disease patients : results of a cross-sectional study

Yzet, C.(1);Brazier, F.(1);Hautefeuille, V.(1);Decrombecque, C.(1);Sarba, R.(1);aygalenq, P.(2);Venezia, F.(3);Buisson, A.(4);Pichois, R.(5);Michaud, A.(6);Fumery, M.(1)*;

(1)CHU Amiens Picardie, Gastroenterology, Amiens, France;(2)Clinique du Palais, Gastroenterology, Grasse, France;(3)Clinique de Bercy, Gastroenterology, Charenton-le-Pont, France;(4)CHU Clermont-Ferrand, Gastroenterology, Clermont-Ferrand, France;(5)CHU Amiens Picardie, Radiology, Amiens, France;(6)CHU Amiens Picardie, Biostatistics, Amiens, France;

Background

Endoscopy is still the gold-standard to assess disease activity in Crohn's disease (CD). Its invasiveness, acceptability and cost limit its use in the era of tight control and treat-to-target. Fecal calprotectin and intestinal ultrasound (IUS) are non-invasive alternatives to colonoscopy to assess disease activity. The objective of this study was to evaluate the performance of IUS and fecal calprotectin to assess mucosal healing in CD.

Methods

All consecutive CD patients who underwent colonoscopy for mucosal healing assessment and IUS and/or calprotectin within 4 weeks between September 2019 and April 2022 were included in a prospective cohort. Bowel wall thickness (BWT) and color doppler signal (CDS) were assessed on each segment. Endoscopic mucosal healing was defined by a CDEIS score < 3.

Results

A total of 153 patients were included, of whom 122 had endoscopic mucosal healing. Eighty-two (53.6%) were female, the median age and disease duration were respectively 36 years (IQR, 28-46) and 10 years (IQR, 4-19). Respectively 56 (56/120, 46.7%) and 93 (93/120, 77.5%) patients presented a BWT < 3 mm and an absence of CDS. The sensitivity (Se), specificity (Sp), positive predictive value (PPV) and negative predictive value (NPV) of BWT < 3 mm to predict endoscopic mucosal healing were 56%, 88%, 95% and 36% (patients misclassified as endoscopic mucosal healing 2.5%). The association of an absent of CDS with a normal BWT did not modify the performances. For a calprotectin < 250 µg/g , The Se, Sp, PPV and NPV were respectively 91%, 63%, 90% and 67% for (patients misclassified 8%). The association of a calprotectin < 250 µg/g, with a BWT < 3 mm and the absence of CDS increased the specificity and the PPV (Se 58%, Sp 95%, PPV 97%, VPN 43%, patients misclassified 1%).

Conclusion

Ultrasound is an efficient non-invasive tool to identify patients with Crohn's disease who have achieved endoscopic mucosal healing.