Search in the Abstract Database

Search Abstracts 2011

* = Presenting author

P033. Neutrophil gelatinase-associated lipocalin (NGAL): A potential biomarker in IBD

K. Oikonomou, A. Kapsoritakis, F. Tsiopoulos, A. Tsimperidis, N. Magaliou, K. Andritsopoulos, A. Manolakis, I. Tsiompanidis, A. Psychos, S. Potamianos

University of Thessaly, Larissa, Greece

Objective: Neutrophil gelatinase-associated lipocalin (NGAL) is a 25kDa protein mainly secreted by neutrophils. NGAL exerts anti-bacterial and matrix degrading properties, while it is suggested to play a modulatory role in proliferation, apoptosis and differentiation. Up-regulation of NGAL levels has been demonstrated in various inflammatory conditions, while over-expression of NGAL in colon epithelium has been shown in inflammatory bowel disease (IBD). We performed the first study analyzing serum NGAL levels in IBD patients, with regard to specific characteristics of patients and disease.

Methods: Serum NGAL was determined by sandwich enzyme-linked immunosorbent assay (ELISA) in 181 IBD patients (93 with UC and 88 with CD), 82 healthy controls (HC) and 41 with irritable bowel syndrome (IBS). Factors that might impact NGAL levels were also quantified and added to univariate and multivariate analyses, in addition to phenotypical disease characteristics.

Results: Serum NGAL levels were elevated in all IBD patients (88.19±40.75 ng/mL) compared with either HC (60.06±24.18 ng/mL, p < 0.0001) or IBS patients (60.80±20.30 ng/mL, p < 0.0001). The same level of significance, p < 0.0001, was exhibited when serum NGAL concentrations of UC (86.62±35.40 ng/mL) and CD (89.92±46.05 ng/mL) patients were separately compared with concentrations in HC or IBS patients. Furthermore, significantly higher levels of serum NGAL were observed in patients with active IBD (120.1±38.46) in comparison with those with inactive IBD (61.58±15.98), p < 0.0001. Similarly, serum NGAL was significantly increased in active UC (120.10±33.65 ng/mL) and active CD (120.06±42.11 ng/mL) in comparison with inactive UC (66.41±15.61 ng/mL, p < 0.0001) and inactive CD (54.37±13.79 ng/mL, p < 0.0001). Serum NGAL (cutoff value: 75 ng/mL) distinguished active IBD from controls exhibiting a specificity of 95% when compared with HC or IBS and a sensitivity of 83% and 73%, respectively. In addition, a cutoff point of 96 ng/mL was set to discriminate active IBD (UC, CD or both) from inactive IBD, demonstrating a sensitivity of 100% and an overall specificity of 68% (74% in UC and 65% in CD). A strong correlation between serum NGAL and C-reactive protein was observed in all IBD patients (Spearman r = 0.38, p < 0.0001).

Conclusions: Serum NGAL may provide information supplementary to established biomarkers and contribute to diagnosis and assessment of activity in IBD, as well as to discrimination of IBD from IBS.