The Analysis Of The Relationship Of Vitamin D With Clinical Factors And Immune Cells In Patients With Inflammatory Bowel Disease

Background:The morbidity of inflammatory bowel disease (IBD) in the Asia Pacific region keeps on rising in recent years. The pathogenesis of IBD is very complicated and the immune system seems to play a rather important role. Due to the immunomodulatory effect, vitamin D gradually attracted people’s attention. And its relationship with IBD could not be overlooked. Studies overseas showed that IBD patients tend to be vitamin D deficient which is related to disease activity to some extent. However, the conditions in China are barely clear. Vitamin D, the overall effect of which is to reduce the immune response of effector T cells (Teff), is widely expressed in many immune cells and functions as an immune regulator via the VDR. Still its underlying mechanism remains unclear.Aim of the study:To understand vitamin D deficiency status in the IBD population and its related clinical factors. To understand the relationship between vitamin D and immune cells in colonic mucosa of UC patients.Patients&Methods:Ⅰ.282IBD cases (174UC cases and108CD cases) and120controls were enrolled into the study and their serum25-OHD levels were colleted. Gender, disease duration, disease activity, disease extent, medication history and other clinical data were analyzed.Ⅱ. We selected41cases of UC to perform immunohistochemical staining for CD4, Foxp3, and the S100on intestinal biopsy specimens. The positive cells were counted and analyzed with clinical data including serum25-OHD level.Results:Ⅰ.①Serum25-OHD levels in UC group, CD group and control group were9.71±4.24ng/ml and9.91±4.55ng/ml and12.84±4.32ng/ml, respectively. The25-OHD level of case group was significantly lower than that of control group. However, there was no statistically significant difference between UC group and CD group. The percentage of severe vitamin D deficiency was also higher in IBD group than that in the control group.②Serum25-OHD levels of UC and CD patients were associated with disease activity with the former more significant.③The female gender was related with low serum vitamin D level in UC patients. Moreover, the use of anti-TNF-a agents and the penetrating disease behavior in CD were associated with high levels of serum25-OHD. However, age, duration, location of disease, smoking history and use of steroids and/or immunosuppressive agents were not statistically related to serum25-OHD level.Ⅱ.①In UC patients, the mucosal CD4+, Foxp3+, S100+cell counts were significantly higher than those in control group. And the positive cells congregated in the lamina propria. But no statistically significant related clinical factors was observed.②One exception was the negative correlation between Foxp3+/CD4+ratio and serum25-OHD level in UC patients. Additionally, the Foxp3+and CD4+cell count were mutually related.Conclusions:Ⅰ. The serum25-OHD level is low in IBD group compared with that in control group, and is negatively correlated with disease activity. Gender in UC patients, use of anti-TNF-a agent and disease behavior in CD patients also affect serum25-OHD level.Ⅱ. CD4+, Foxp3+, S100+cell counts in the colonic mucosa of UC patients were higher than those of control. Foxp3+/CD4+ratio in UC patient was also high and negatively correlated with serum25-OHD level.