Relationship between neutrophil gelatinase-associated lipocalin (NGAL) levels and inflammatory bowel disease type and activity.

BACKGROUND AND AIM

Neutrophil gelatinase associated lipocalin (NGAL) is a recently identified molecule, which is bacteriostatic, has tissue destructive effects and is pro-inflammatory with chemoattractant molecule binding properties. Our aim was to investigate the relationship between serum NGAL levels and the type and level of disease activity of IBD.

METHODS

A total of 92 patients [43 with Crohn's disease (CD) and 49 with ulcerative colitis (UC)], and 30 age- and sex-matched healthy controls (HC) were included in this study. Serum NGAL levels were measured using ELISA.

RESULTS

Serum NGAL levels were elevated in the IBD group [median 171, range (57-312) ng/mL] compared to the HC group [107 (45-234) ng/mL] (p<0.0001) and were elevated in UC patients [188 (74-312) ng/mL] compared to CD patients [168 (57-279) ng/mL] (p=0.006). When NGAL levels were further analysed based on localization of the CD and UC, the levels in ulcerative pancolitis [233 (144-312) ng/mL] were significantly higher (p=0.004) than the left-sided colitis [156 (103-309) ng/mL]. Similarly, NGAL levels were significantly higher in colonic CD [207 (125-249) ng/mL] than ileal CD [114 (78-210) ng/mL], and also in ileocolonic CD [198 (57-279) ng/mL] than ileal CD (p=0.033). When CD and UC groups were further categorized as active and inactive according to clinical and endoscopic activity indices, serum NGAL concentrations did not differ between inquiescent versus active stages. When a cut-off level of 129 ng/mL was used to distinguish IBD from HC, a sensitivity of 76.1% and a specificity of 60.9% was reached.

CONCLUSIONS

The serum NGAL levels in the IBD group was significantly higher than the HC group. Serum NGAL levels were higher in more extensive colonic involvement.