Objective: To detect the expressions of IL-17, IL-23, IL-22 and IL-11 in the intestinal mucosa of patients with ulcerative colitis (UC) and analyze their prognostic values.
Methods: Forty patients with active UC, 15 with UC in remission and 15 healthy subjects were examined for the expressions and distribution of IL-17, IL-23, IL-22, and IL-11 in the colorectal mucosausing immunohistochemistry. We further collected the data from 40 patients with routine therapy and regular follow-up and compared the expressions of those cytokines according to the condition of mucosal healing.
Results: The expressions of cytokines in patients with active UC were significantly higher than those in patients with remittent UC and healthy control subjects (IL-17: 0.0727∓0.0037 vs 0.0354∓0.0243 vs 0.0330∓0.0045; IL-23: 0.1407∓0.0068 vs 0.0865∓0.0051 vs 0.0442∓0.0137; IL-22: 0.0522∓0.0045 vs 0.0259∓0.0063 vs 0.0115∓0.0061; IL-11: 0.0479∓0.0022 vs 0.0365∓0.0024 vs 0.0232∓0.0009, P<0.05). The expression levels of IL-17, IL-23, and IL-22 increased significantly with the increase of the disease activity (IL-17: 0.0545∓0.0072 vs 0.0786∓ 0.0051 vs 0.0847∓0.0197; IL-23: 0.1112∓0.0046 vs 0.1480∓0.0089 vs 0.1644∓0.0190; IL-22: 0.0307∓0.0063 vs 0.0548∓ 0.0071 vs 0.0719∓0.0056, P<0.05). In patients with active UC, the expression levels of the 4 cytokines in the intestinal mucosa were positively correlated with the endoscopic activity grade (P<0.05), and IL-17 and IL-22 expression levels were also positively correlated with the histological grade (P<0.05). All the 4 cytokines were positively intercorrelated. The patients with low IL-17 expression (25.00%) showed a significantly lower rate of poor mucosal healing than those with high IL-17 expressions (25% vs 67%, P<0.05).
Conclusion: The cytokines IL-17, IL-23, IL-22, and IL-11 all participate in the pathogenesis of UC and may serve as indicators for evaluating the inflammatory activity. The expression level of IL-17 can be a valuable indicator for predicting mucosal healing in UC patients after a short-term treatment.