Evaluation of serum neutrophil gelatinase-associated lipocalin (NGAL), asymmetric dimethylarginine (ADMA) and symmetric dimethylarginine (SDMA) levels, and their relations with disease type and activity in inflammatory bowel diseases

Background/aim: Inflammatory bowel disease (IBD) mainly encompass two entities called ulcerative colitis (UC) and Crohn's disease (CD), both of which are chronic, progressive and, inflammatory conditions of the gastrointestinal tract. Various indicators and non-invasive markers have been sought and used in IBD patients to help assessing disease activity and treatment effectiveness although none of them are proven to yield definite results in full correlation with the clinical, endoscopic, and histopathological examinations. The aim of the current study was to investigate the relationship of serum neutrophil gelatinase-associated lipocalin (NGAL), asymmetric dimethylarginine (ADMA), and symmetric dimethylarginine (SDMA) levels with disease type and activity and to assess their potential use in establishing diagnosis and activity status of IBD, namely UC and CD. Materials and methods: A total of 111 IBD patients with determined active and inactive disease periods and 70 matched controls were recruited. Serum NGAL levels of the patients and the control group were measured using commercially available ELISA kits. ADMA and SMDA levels were measured by high performance liquid chromatography. Results: The IBD group had significantly higher serum levels of NGAL (p = 0.001), ADMA (p = 0.0001), and SDMA (p = 0.0001) in comparison to the control group. Likewise, serum NGAL, ADMA, and SDMA levels were significantly higher in the active IBD group compared to the inactive IBD group (p = 0.0001). Active UC and active CD patients similarly had significantly higher levels of serum NGAL, ADMA, and SDMA than the respective levels in inactive UK and inactive CD patients (p = 0.0001). Conclusion: Serum NGAL, ADMA and SMDA levels are increased in patients with IBD, and serum NGAL, ADMA and SMDA concentrations are significantly higher in active IBD patients than inactive IBD patients. Our results suggest these biomarkers may serve in estimating IBD activity and severity.