The expression of interleukin-25 in patients with inflammatory bowel disease and its clinical significance

Abstract

Objective To explore the function and significance of interleukin(IL)-25 in the pathogenesis of inflammatory bowel disease (IBD) through testing its expression in the intestinal mucosal and serum of patients with IBD. Methods Intestinal or colonic mucosal biopsies of 12 patients with ulcerative colitis (UC), 16 patients with Crohn's disease (CD) and 10 healthy controls were collected. The expression of IL-25 at mRNA level was detected by real-time PCR and the situ expression of IL-25 in intestinal mucosa was analyzed with immunohistochemistry. At same time,serum of 20 UC patients, 24 CD patients and 20 controls was collected, and IL-25 concentration in the serum was determined by enzyme-linked immunosorbent assay (ELISA). Results Compared with healthy controls, the expression of IL-25 at mRNA level in inflamed mucosa of CD and UC patients was significantly decreased (P＜0.05), no statistic difference between UC and CD groups (P＞0.05).The immunohistochemistry results indicated that more IL-25 positive cells in normal lamina propria,the expression of IL-25 in mucosal epithelia cells was low, the expression of IL-25 protein in the intestinal or colonic mucosa of UC and CD patients significantly decreased ( P ＜ 0.05), no statistic difference between UC and CD groups (P＞0. 05). ELISA results showed that the level of IL-25 in the serum of UC and CD groups was significantly lower than healthy controls (P ＜ 0.05). Conclusion The expression of IL-25 in the intestinal mucosa and serum of IBD patients was significantly decreased,which suggested that IL-25 expression defects may closely related to the pathogenesis of IBD. IL-25 may be a new target for the IBD treatment. Key words: Crohn's disease; Inflammatory bowel disease; Ulcerative colitis; Interleukin-25