P214 What is the diagnostic accuracy of faecal calprotectin regarding endoscopic relapse in Crohn's disease patients following ileocecal resection? A tertiary single center experience
Yıldırım S., Demir N., Bozcan S., Erzin Y., Hatemi I., Celik A.F.
Istanbul University Cerrahpasa School of Medicine, Gastroenterology, Istanbul, Turkey
There is still some discrepancy about the accuracy of faecal calprotectin (FC) in Crohn's disease (CD) patients after ileocecal resection and data from real daily practise on this topic is still scarce.
For this purpose we prospectively gathered the simultaneous FC results of CD patients who were referred to the endoscopy unit in the postoperative (postop) setting. Patients with upper GI involvement were excluded. Demographic data like age, sex, disease duration, Rutgeerts score, FC, CRP results were all noted. All patients gave a stool sample 24 hours before colonoscopy and FC was determined via ELISA (Quantum Blue Calprotectin, Bühlmann Lab. AG, Switzerland).
Seventy-four CD patients [38 female (51%)] with an ileoceal resection were enrolled into the study protocol. Their mean age was 38.56±12 yr. with a mean disease duration of 123.52±84.88 mo. Fourty-four of 74 (60%) patients were in endoscopic remission whereas 30 (40%) had endoscopic relapse [i0- 31 patients (42%); i1- 13 patients (18%), i2- 11 patients (15%), i3- 14 patients (19%), i4- 5 patients (6%)]. Nonparametric Spearman correlation test only revealed that FC using a cut off of 30 μg/g weakly correlated with endoscopic relapse (r=0.329, p=0.004). Diagnostic accuracies of FC using different cut offs is shown in Table 1.
Cut-off values for FC Sensitivity (%) Specificity (%) PPV (%) NPV (%) Diagnostic accuracy (%) 30 μg/g 97 30 48 93 57 50 μg/g 80 34 45 71 53 100 μg/g 67 50 48 69 57
According to our results from our daily routine practise, the very low specificity of FC for each cut off in CD patients with an ileocecal resection lets us question the diagnostic utility of this non-invasive marker as an alternative tool to colonoscopy in the postop setting. A speculative explanation for this could either be the presence of unidentified lesions proximal to the ileocolonic anastomosis or ischemic anastomotic ulcers which might have been the reason behind the confusion of the endoscopist and let us judge the value of Rutgeerts score.