P183 Diagnostic value of fecal gelatinase-associated lipocalin as a surrogate marker of inflammation in Inflammatory Bowel Diseases
D. Mukhametova1, D. Abdulganieva*1, O. Zinkevich2, N. Saphina2, A. Odintsova3, M. Koporulina2
1Kazan State Medical University, Hospital Therapy with the course of Endocrinology, Kazan, Russian Federation, 2Kazan State Medical Academy, Central Scientific Research Laboratory, Kazan, Russian Federation, 3Republican Clinical Hospital, Gastroenterology, Kazan, Russian Federation
Nowadays, there is a need for the use of non-invasive laboratory surrogate markers of intestinal inflammation in inflammatory bowel diseases (IBD). Fecal gelatinase-associated lipocalin (NGAL) secreted by neutrophils and epithelial cells during inflammation and possibly can be used as a marker of inflammation. Aim: to evaluate the diagnostic value of fecal NGAL as a surrogate marker of inflammation in IBD.
30 patients with active IBD (9 pts with Crohn's disease, 21 - ulcerative colitis) and 11 healthy controls were included into the study. Fecal NGAL was determined by ELISA in fecal specimens. We used a set of Human Lipocalin-2 / NGAL ELISA, production BioVendor, Czech Republic. ROC-analysis was done to determine the diagnostic value of fecal NGAL - to define the cut point, sensitivity, specificity, and area under the curve (AUC). Also positive predictive value (+PV), negative predictive value (-PV), positive likelihood ratio (LR +) and negative likelihood ratio (LR-) were calculated.
Fecal NGAL was significantly higher in patients with active IBD [4892,5 ng/ml (2730 ng/ml; 9424 ng/ml) compared with healthy controls [433 ng/ml (169 ng/ml; 850 ng/ml) (p<0,01). ROC-analysis (Figure 1) defined the threshold of fecal NGAL as a marker for determining an active phase of inflammation in IBD - 1029 ng/ml, to which were empirically determined sensitivity of 80%, specificity of 90,9%, and AUC - 0,9. Further we constructed 2x2 Table to determine the diagnostic values: +PV - 96%, -PV - 62,5%, LR+ - 8,8 and LR- - 0,22. Thus, the findings suggest that studied indicator have high resolution in identifying IBD.
Fecal NGAL is a novel non-invasive marker to distinguish active IBD from healthy individuals with a high sensitivity, specificity and AUC. Fecal NGAL might be used as one of the non-invasive biomarkers of intestinal inflammation.