Serum Interleukin-23 Levels in Patients with Ulcerative Colitis

Background: Patients with ulcerative colitis are at increased risk of inflammation. Interleukin 23 (IL-23) is a newly identified cytokine with increased expression in inflamed biopsies of colon mucosa in patients with Crohn's disease; however, there is inconsistent evidence on its role in ulcerative colitis. Objective: We aimed to compare serum IL-23 level in patients with ulcerative colitis and normal controls and determine if serum IL-23 level increases with the severity of disease according to endoscopic findings. Methods: We quantified serum IL-23 levels from 60 patients with ulcerative colitis and 20 control individuals. All patients underwent endoscopic procedure to define the severity of disease. Patients were then stratified into 2 groups of "Mild" and "Severe" according to the endoscopic findings. Results: For comparison of serum IL-23 levels, Platelet count, ESR and CRP between the groups, Mann-Whitney U test and independent sample t test were employed, as appropriate. Pearson’s and spearman's correlation tests were employed to test the association of IL-23 with platelet count, CRP and ESR in patients. Our findings showed that serum IL-23 levels were increased in patients with ulcerative colitis compared to normal control. Moreover, patients in "Severe" group had higher serum IL-23 levels and ESR compared with those in "Mild" group. There was no significant sexual dimorphism in any of studied variables. Conclusion: We suggest that IL-23 plays an important role in the pathogenesis of ulcerative colitis and is a marker of disease activity in these patients.