[Expression and significance of mucosal beta-defensin-2, TNFalpha and IL-1beta in ulcerative colitis]

To investigate the expression and significance of human beta-defensin-2 (HBD2), TNFalpha and IL-1beta in ulcerative colitis (UC).

Thirty-five patients with active UC diagnosed by the department of gastroenterology in West China Hospital were included in this study. Ulcerative colitis disease activity index (UCAI) was assessed and the pathological grades of UC were classified. Immunohistochemistry assay and real-time quantitative PCR were used for the expression of HBD2, TNFalpha, IL-1beta in colonic mucosa of UC.

Among the 35 patients with UC, 10 cases were mild, 13 moderate and 12 severe. Of the 35 cases, there were 11 with grade I, 13 grade II and 11 grade III lesion according to Truelove criteria. The score of UCAI had positive correlation with pathological grading (r = 0.890, P < 0.01). The expressions of HBD2, TNFalpha, IL-1beta in colonic mucosa of UC with immunohistochemistry and real-time quantitative PCR were significantly higher than those in healthy control (P < 0.05); the expressions increased gradually with the severity of pathological grade and there was a higher expression of them in inflamed area than in non-inflamed (P < 0.05). A good positive correlation was also found between HBD2 and other inflammatory cytokines.

It is shown that there is a higher expression of HBD2 in colonic mucosa as compared with healthy control, a higher expression of it in inflamed area than in non-inflamed area and a positive correlation of expression between HBD2 and pro-inflammatory cytokines such as TNFalpha and IL-1beta, implying that HBD2 and pro-inflammatory cytokines are interdependent and interactive playing an important role in magnifying and aggravating inflammatory injury in UC.