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.

Background:There is no specific therapy for inflammatory bowel disease(IBD),and the pathogenesis of IBD is not fully clear. Aims:To explore the expression and clinical significance of IL-17BR in colon mucosa and peripheral blood mononuclear cell(PBMC)of patients with IBD. Methods:Colon mucosal biopsy specimens of 40 Crohn's disease(CD) patients,32 ulcerative colitis(UC)patients and 25 healthy controls and PBMC of 30 CD patients,27 UC patients and 25 healthy controls were collected. The expressions of IL-17BR in colon mucosa and PBMC were determined by immunohistochemistry and flow cytometry,respectively,and correlations between IL-17BR expression and levels of CRP, ESR,CDAI score and Mayo score were analyzed. Serum levels of TNF-α before and after infliximab(IFX)treatment were determined by ELISA,and correlations with IL-17BR were analyzed. Results:Compared with healthy controls,IL-17BR expressions in colon mucosa of CD and UC patients were significantly increased(P<0.05). IL-17BR expressions were significantly higher in active CD and UC patients than in remission CD and UC patients(P <0.05). No significant differences in IL-17BR expression in PBMC were found among CD,UC patients and healthy controls(P>0.05). The expression of IL-17BR in colon mucosa was positively correlated with CRP,ESR,CDAI score or Mayo score in CD,UC patients(P <0.05). After treatment with IFX,expression of IL-17BR in colon mucosa and serum TNF-α level were significantly decreased in CD patients(P<0.01). Expression of IL-17BR was positively correlated with serum TNF-α level in CD patients(P<0.05). Conclusions:The increasing of IL-17BR expression in IBD patients is closely correlated with activity of inflammation and TNF-α level. IL-17BR may play a vital role in immune response of intestinal mucosa,and can be used as a new marker for reflecting the activity of IBD.