A94 USE OF LOW-DOSE CTE IN PREDICTING ACTIVE INFLAMMATION IN CROHN'S PATIENTS WITH INTERMEDIATE FECAL CALPROTECTIN LEVELS. (1st March 2018)

• Record Type: Journal Article
• Authors: Gerami, O; Brown, J; Vos, P; Leipsic, J; Lee, T; Enns, R A; Bressler, B; Rosenfeld, G
• Is Part Of: Journal of the Canadian Association of Gastroenterology. Volume 1(2018)Supplement 1
• Page Start: 165
• Page End: 166
• Publication Date: 2018-03-01
• Subjects: Gastroenterology -- Periodicals; 616.33005
• DOI: 10.1093/jcag/gwy008.095
• Languages: English
• ISSNs: 2515-2084

Abstract

Abstract: Background: Crohn's disease (CD) is a condition that affects young individuals. Clinically assessed disease activity by a Gastroenterologist is the gold standard for identifying patients with active inflammation and relapse. Fecal Calprotectin (FC) is a biomarker that is an independent indicator of active inflammation. Bressler et al has shown that FC levels <100 µg/g strongly predict quiescent CD, and those >250 µg/g strongly predict active inflammation/relapse. FC levels between 100–250 µg/g is an indeterminate zone that warrants further testing to confirm the presence/absence of disease. Computed tomography enterography (CTE) is a proposed next test. Recent research has shown that low-dose CTE using model-based iterative reconstruction (MBIR) is non-inferior to standard dose CTE for identifying signs of small bowel inflammation. Aims: To assess the utility of MBIR CTE signs, in patients with intermediate FC levels, for predicting those who would have active inflammation on clinical assesment. Methods: A single-center, retrospective cohort study of 163 patients subjected to clinical assessment, FC measurement and low dose CTE to evaluate CD activity between November 2012 & February 2015. The CTE studies for each patient were reviewed by two radiologists for radiographic findings of small bowel CD inflammation. Clinically assessed disease activity by a Gastroenterologist served as the reference standard. Multivariate logistic regression was used to build a scoring equation based on FC levels & radiographic signs to predict active disease in the reference standard. Results: Of the 163 patients, 92 (56%) patients had active inflammation based on clinical assessment. Sixty-five (71%) of the 92 patients clinically diagnosed with active inflammation also had CTE that was deemed active by overall radiologist impression. Fifty (70%) of the 71 patients clinically diagnosed with inactive inflammation also had CTE that was deemed inactive by overall radiologist impression. Sensitivity, specificity, PPV & NPV of overall radiologic impression for CD activity was 0.70, 0.71, 0.75, 0.65, respectively. 138 patients had measured FC levels. Seventy-eight (57%) had clinically active disease & 60 (43%) had clinically inactive disease. In those with active disease, 16 (20%), 13(17%) & 49(63%) had FC levels <100 µg/g, 100–250 µg/g, >250 µg/g, respectively. In those with inactive disease, 53 (88%), 7(12%) & 0(0%) had FC levels <100 µg/g, 100–250 µg/g, >250 µg/g, respectively. An equation based on mural stratification & FC level predicted active disease the best. This equation had a sensitivity, specificity, PPV, NPV & accuracy of 0.82, 0.90, 0.91, 0.79 & 0.85, respectively. Conclusions: In patients with FC levels between 101–250, MBIR CTE is a reasonable further test to confirm the presence/absence of disease Funding Agencies: None