P174 Diagnostic value of a novel combination score of disease activity in a real-life IBD cohort.
A. Bodelier*1, 2, D. Jonkers2, T. Van den Heuvel2, E. de Boer2, W. Hameeteman2, A. Masclee2, M. Pierik2
1Amphia Ziekenhuis, Internal Medicine & Gastroenterology, Breda, Netherlands, 2Maastricht University Medical Center+, Internal Medicine - Division Gastroenterology-Hepatology, Maastricht, Netherlands
Monitoring of mucosal inflammation in inflammatory bowel disease (IBD) is of major importance to improve the long term outcome. Clinical activity indices however have shown insufficient correlation with endoscopic disease activity in Crohn's disease (CD). Fecal calprotectin (FC) is a better predictor of endoscopic activity but values between 100-250 µg/g are difficult to interpret. Therefore, the aim of our present study was to evaluate the role of FC and the additional value of a combination of non-invasive markers, especially in patients with indefinite FC values, for assessment of disease activity in a real-life IBD cohort.
Three hundred and three consecutive IBD patients were enrolled and participated in a 1 year prospective follow-up study. Patients were assessed during routine outpatient clinic visits or when a flare occurred. Clinical disease activity was scored by Harvey Bradshaw index or Simple Clinical Colitis Activity Index, also C-reactive protein (CRP) and FC were determined. We defined FC levels between 100-250 µg/g as inconclusive. Endoscopic evaluation was performed when indicated. Endoscopic disease activity was determined by the Simple Endoscopic Score-CD and Mayo endoscopic subscore in ulcerative colitis (UC). Clinical activity index, CRP and FC were combined into a new combination score and evaluated in the cohort of patients who underwent an endoscopy. Patients with inconclusive FC values were re-classified with the combination score.
Inconclusive FC values were present in 24% (CD) and 15% (UC) of the patients. In both CD and UC more patients had active disease according to the combination score (47% and 39%) than with assessment of FC alone (26% and 32%). In CD, the combination score could predict endoscopic disease activity with sensitivity of 79%, specificity of 58% (positive predictive value (PPV) 54%, negative predictive value (NPV) 82%). In UC this was 85% and 57% (PPV 88%, NPV 50%). All patients with inconclusive FC values could be classified with the new combination score.
In our real-life cohort of IBD patients, a substantial part of patients has inconclusive FC values. The combination of FC with clinical activity indices or CRP helped to classify disease activity in these patients. We think that the concept of combining non-invasive markers is an interesting new tool in the search for reliable and easy to use surrogate markers for endoscopy in daily clinical practice.