ABSTRACT
Objective To investigate the role of bacterial flagellin and CD98 in ulcerative colitis (UC).Methods A total of 60 first episode patients with active UC were recruited,including 30 mild and 30 moderate to severe UC cases.The serum of 30 healthy volunteers and normal intestinal tissues surgically removed from 15 colon cancer patients (more than 5 cm away from surgical margins) were collected as control.The content of bacterial flagellin antibodies in peripheral blood were measured with enzyme-linked immunosorbent assay (ELISA).The expression of CD98 in peripheral blood T lymphocyte was measured by flow cytometry (FACS).The expression of bacterial flagellin protein in intestinal mucosa and CD98 in intestinal epithelial basement membrane was tested by immunohistochemistry (IHC).The comparison between two groups was performed with the SNK-q method,the R×C table x2 test was used to analyze the counted data,and the Spearman correlation was used to analyze the rank materials.Results The peripheral blood concentration of bacteria flagella protein antibody of control group,mild UC group and moderate to severe group showed an upward trend,which was (7.603±2.118) pg/ml,(13.702±3.131) pg/ml and (20.813±3.004) pg/ml respectively,and the differences among groups were statistically significant (F=13.57,P＜0.01).The expression percentage of bacteria flagella protein in intestinal mucosa of the three groups also showed an upward trend,which was 3/15,56.67％ and 73.33％ respectively,and the differences among groups were statistically significant (x2 =11.553,P=0.003).The positive rate of CD98 expression in peripheral blood T lymphocytes of the three groups showed an upward trend,which was (28.42±4.31)％,(32.45±6.71)％ and (43.40±5.09) ％ respectively,and the differences among groups were statistically significant (x2 =10.110,P=0.007).The positive rate of CD98 expression in intestinal epithelial cells of the three groups also showed an upward trend,which was 1/15,36.67 ％ and 66.67％ respectively,and the differences among groups were statistically significant (x2 =5.400,P＜0.05).There was positive correlation between the peripheral blood concentration of bacteria flagella protein antibody and the expression of CD98 in peripheral blood T lymphocytes (r=0.548,P＜0.05).Conclusion Bacterial flagellin and CD98 may be important factors causing inflammatory reaction activity in UC.