Faecal Neutrophil Gelatinase-associated Lipocalin as a Non-invasive Biomarker in Inflammatory Bowel Disease

Today, there is an ongoing search for new inflammation markers of inflammatory bowel disease (IBD). A novel promising one is a neutrophil gelatinase-associated lipocalin (NGAL), produced by neutrophils and intestine epithelial cells in inflammation. We propose that it is important to evaluate the role of faecal NGAL as an intestinal inflammation marker. The aim was to evaluate NGAL level in faeces in patients with IBD. We included 107 patients with IBD — 96 cases of IBD flare up (66 — UC and 29 — CD), 11 patients in IBD remission (6 — UC and 6 — CD) and 30 healthy controls. There was a confirmed faecal NGAL level in all patients. Faecal NGAL was significantly higher in active IBD — 4122 [861; 6850] ng/ml comparing with healthy persons — 181 [169; 720] ng/ml ( p < 0,001) or inactive IBD — 1136 [116; 3004] ng/ml ( p < 0,05). In active UC (4668 [1298; 7792] ng/ml), it was higher than in active CD (2688 [200; 5710] ng/ml) ( p < 0.05). We found that faecal NGAL as a marker has sensitivity of 72.9%, specificity of 93.3% and AUC of 0.88 for distinguishing IBD from healthies. Sensitivity, specificity and AUC were 72.9%, 45.5% and 0.72, respectively, for distinguishing exacerbation from remission of disease. Faecal NGAL is a new promising marker for diagnosis active IBD, which has high sensitivity, specificity and AUC. It can greatly expand number of non-invasive biomarkers of intestinal inflammation for using in clinical practice.