P389. Reactive oxygen metabolites and antioxidants as biomarkers of disease severity in ulcerative colitis
B. Canbakan1, M. Tuncer1, E. Koroglu1, A. Sonsuz1, H. Senturk2, 1Istanbul University Cerrahpasa Medical Faculty, Gastroenterology, Istanbul, Turkey, 2Bezmi Alem University, Gastroenterology, Turkey
Neutrophil accumulation in the mucosa and the subsequent induction of oxidative stress correlate with clinical disease activity in ulcerative colitis (UC). We investigated the redox parameters in tissue specimens and their correlations with clinical activity index in UC.
35 patients with ulcerative colitis (M/F: 18/17; mean age 38.14±13.6) were compared with 29 control subjects (M/F: 15/14; mean age 45.96±14.43 years). Mucosal biopsies were obtained from patients with active UC. Disease activity was assessed using Truelove–Witts classification. Index values below 150, values between 150 and 220, and values above 220 corresponded to mild, moderate, and severe disease, respectively. Oxidative stress was estimated on the basis of malondialdehyde (MDA), superoxide dismutase (SOD), glutathione peroxidase (GPO), and myeloperoxidase (MPO) levels in tissue specimens, using the thiobarbituric acid-trichloroaceticacid assay for MDA-, phenyltetrazolium chloride assay for SOD-, method of Paglia and Valentine for GPO-, and tetramethyl benzidin assay for MPO measurement. For statistical analysis chi-squared, Student's t-tests, and Spearman correlation test were used.
In control subjects MDA levels correlated positively with GPO, MPO and SOD levels (r = 0.79, p = 0.01, r = 0.76, p = 0.01, r = 0.39, p = 0.030). MDA level of patients with mild AI correlated positively with GPO and SOD levels (r = 0.79, p = 0.01, and r = 0.86, p = 0.01). Patients with high AI had a weak significant positive correlation between MDA and SOD levels (r = 0.68, p = 0.049). Patients with mild and moderate AI had similar MDA levels as the controls. Patients with severe AI had significantly higher MDA and MPO levels than the controls (p = 0.03, and 0.004, respectively). Patients with moderate AI had significantly higher MPO and GPO levels (p = 0.002, and 0.044, respectively).
We found increased ROS and antioksidants levels in patients with severe clinical AI. There was a less prominent positive correlation between ROS and antioxidants in patients with moderate and severe AI as compared with control subjects and patients with mild AI. When the oxidative stress overrides the antioxidant capacity, the insufficient production against oxidative stres induces progression of clinical disease severity. Therefore, in UC therapeutic interventions should be aimed to improve the antioxidant status.