P238 Accuracy of fecal calprotectin predicting endoscopic activity in Inflammatory Bowel Disease patients
V. Jusué, M. Chaparro, J.P. Gisbert*
Hospital Universitario de La Princesa, IIS-IP and CIBERehd, Gastroenterology Unit, Madrid, Spain
Fecal calprotectin (FC) is a noninvasive marker of inflammation used in inflammatory bowel disease (IBD).
Aim: To evaluate the accuracy of FC to predict the presence of endoscopic activity in patients with IBD. To establish the best cut-off concentrations to predict endoscopic activity.
We prospectively included 88 patients with IBD who underwent an endoscopy for clinical indication. The Quantum Blue® Bühlmann kit was used to determine FC concentration. Two different kits, of low and high range, were used for each sample. Endoscopic activity was calculated by the Mayo endoscopic subscore for ulcerative colitis (UC), and the SES-CD for Crohn's disease (CD). CD patients with ileal disease whose ileum had not been examined during the endoscopy were excluded. Clinical activity was calculated by the partial Mayo score for UC and the Harvey-Bradshaw index for CD, and the values of various serum markers of inflammation (platelets, leukocytes, CRP and albumin) were recorded
88 patients have been included up to now. The concentration of FC was higher in UC patients with endoscopic lesions compared with those without endoscopic activity, with the low-range kit (216 ± 110 vs. 53 ± 61 mg/g, p<0.05) as well as with the high-range kit (635 ± 401 vs. 146 ± 149 mg/g, p<0.05). We also found statistically significant differences in the concentration of FC in CD patients with and without endoscopic activity, with the low (158 ± 113 vs. 77 ± 92 mg/g, p<0.05) and with the high-range kit (507 ± 474 vs. 223 ± 294 mg/g, p <0.05). The concentration of the different serological markers (platelets, leukocytes, CRP and albumin) was not different in patients with and without endoscopic activity. The area under the ROC curves of FC concentration for the prediction of endoscopic activity in UC were 0.88 and 0.86 with low and high-range kits, respectively, and 0.75 with both kits in CD. The best cut-off points for the detection of endoscopic activity in UC patients were 50 mg/g for the low-range kit (sensitivity 88%, specificity 86%, positive predictive value [PPV] 75% and negative predictive value [NPV] 91%) and 102 mg/g for the high-range kit (sensitivity 78%, specificity of 77%, PPV 74% and NPV 88%). In CD patients, the best cut-off points were 54 mg/g for de low-range kit (sensitivity 75%, specificity 72%, PPV 75% and NPV 71%) and 115 mg/g for the high-range kit (sensitivity 75%, specificity 71%, PPV 74% and NPV 78%).
The determination of FC concentration has good diagnostic accuracy for the detection of endoscopic activity in IBD (better for UC than for CD patients).