Urinary NGAL in gastrointestinal diseases can be used as an indicator of early infection in addition to acute kidney injury marker.

Background And Aim: Neutrophil gelatinase-associated lipocalin (NGAL) is characterized by increased expression before the rise in serum creatinine and has been used as a biomarker for the early prediction of acute kidney injury (AKI). However, there have been no comprehensive analyses of its significance in gastrointestinal diseases. This study aimed to analyze the usefulness of measuring urinary NGAL levels in patients with gastrointestinal diseases.

Methods: This study included 171 patients with a wide range of gastrointestinal diseases. Urinary NGAL levels were measured in all patients within 24 h of admission and 72 h later.

Results: Urinary NGAL levels were higher in patients with acute pancreatitis and acute cholangitis/cholecystitis than in those with other diseases. Although lower than in these diseases, urinary NGAL tends to be higher in inflammatory bowel diseases, such as ulcerative colitis and Crohn's disease, as well as in acute and chronic liver diseases, and is higher in liver cirrhosis as the Child-Pugh grade increases. Furthermore, we found that the group with higher urinary NGAL levels, which continued to increase over time, had worse hospital stays and prognosis.

Conclusion: Urinary NGAL could be used as an indicator of infectious diseases rather than an indicator of AKI in inflammatory bowel diseases and cirrhosis, and could predict the prognosis of patients with gastrointestinal diseases.