The Contents Of IL-33 In Serum And The Expression Of IL-33 In Intestinal Mucosa Of IBD Patients

BackgroundInflammatory bowel diseases(IBD) as ulcerative colitis(UC) and Crohn's disease(CD) are a chronic inflammatory bowel diseases that has the characteristic in clinical with difficulty in cure and recurrent attack. IBD affects the quality of life of patients seriously. In recent years, the incidence of IBD has increased a lot in Asia. Although the pathogenesis of IBD is not yet clear, the current studies show that the occurrence of the IBD is affected by genetic, environmental and immune. Cytokines play an important role in it by analyzing the immunologic process of patients with UC and CD. The studies indicated that IL-33 involved in the development of process in the regulation of inflammatory response, infectious diseases, cardiovascular diseases, cancer and other diseases, when combined with receptor of ST2 and activated the intracellular signaling pathway of NF-?B. The latest studies also showed that there was an abnormal expression of interleukin 33(IL-33) in serum and intestinal mucosa in IBD patients. Is there a certain relationship between IL-33 and the occurrence of IBD? ObjectiveTo explore the relationship between the contents of IL-33 in serum and the expression of IL-33 in intestinal mucosa and IBD. MethodsIn our study, we enrolled 118 patients with clinical diagnosis of IBD seen at The Sixth People's Hospital of Zhengzhou and 40 healthy control subjects during the period from September 2013 to September 2015. The diagnosis of UC and CD was based on the diagnostic criteria established by Chinese Society of Gastroenterology depending on a combination of clinical, laboratory, imaging, endoscopic, and histopathology features. According to the type of disease, the patients were divided into two groups, including UC of 65 cases(male 34, female 31; mean age 44.22±14.74) and CD of 53 cases(male 30, female 23; mean age 38.77±11.24). and the extent of the disease in UC and CD were classified mild, moderate and severe. The activity of UC was evaluated by the Mayo score, and the activity of CD was evaluated by the CD activity index score(CDAI). All the participants were collected venous blood 2ml in fasting, after centrifugation, and then detecting the expression level of IL-33 in serum by ELISA. 4 pieces of intestinal mucosa were removed by colonoscopy in IBD patients and then placed in liquid nitrogen immediately. and in control group, 4 pieces of normal intestinal mucosa were removed by random. In the same treatment, the expression of IL-33 in intestinal mucosa was detected by qRT-PCR in two groups, comparing the results and analyzed statistically. ResultsCompared with control group, the expression level of IL-33 in serum in UC group and CD group was significantly higher(p<0.001, p=0.008); There was a significant difference to compare the mild with moderate and severe of UC(P=0.009,P<0.001). and Mayo score of UC was positive correlation(r=0.625 p<0.05). There was no statistical difference to compare moderate with severe of UC, UC group with CD group as well as mild, moderate and severe of CD(P=0.51, P=0.53, P>0.05). There is a significant difference in the expression level of IL-33 mRNA to compare the group of UC and CD with control(P<0.05). and the expression in the group of UC is higher than CD. The study also found that there was no difference in the expression level of IL-33 mRNA in the groups of mild, moderate and severe(P?0.05), even though the expression level of IL-33 mRNA was ascending in the groups of mild, moderate and severe in turn. Conclusion A significant association was found between the expression of IL-33 in serum and IBD. The expression of IL-33 in serum was positively correlated with the activity of UC. while there was no significant difference in the groups of CD. the expression level of IL-33 mRNA in intestinal mucosa of IBD patients was high, groups of UC was higher than groups of CD, but there was no significant difference in the groups of mild, moderate and severe of UC and CD. IL-33 may play a role in the development of IBD, especially in UC, providing new targets and therapeutic methods for clinical application.