[Expression of human beta-defensin 2 and tumor necrosis factor-A in colonic mucosae of ulcerative colitis and diarrhea-predominant irritable bowel syndrome].

OBJECTIVE: To detect the expression of human beta-defensin 2 (HBD-2) and tumor necrosis factor-alpha (TNF-alpha) in the colonic mucosae of ulcerative colitis (UC) patients and diarrhea-predominant irritable bowel syndrome (IBS-D) patients and to evaluate the roles of HBD-2 and TNF-alpha in the pathogenesis and the relationship between them.

METHODS: Immunohistochemistry was conducted on the biopsy samples of colonic mucosa from 30 UC patients, 20 IBS-D patients, and 10 normal persons to measure the expression of HBD-2 and TNF-alpha.

RESULTS: The expression levels of HBD-2 and TNF-alpha in the colonic mucosa of UC were both significantly higher than those in the colonic mucosa of IBS-D (z = -4.856, z = -3. 987, all P < 0.01) and in the normal colonic mucosa (z = -3.611, z = -3. 248, all P < 0.01). But no significant differences were found between the colonic mucosa of IBS-D and the normal colonic mucosa in the intensity of the expressions of HBD-2 and TNF-alpha (z = -0.373, z = -0.032, all P > 0.05). There were no significant differences in the intensity of the expressions of HBD-2 and TNF-alpha in colonic mucosa of among the mild, moderate, and severe UC (chi2 = 1.190, P > 0.05, chi2 = 1.672, P > 0. 05).

CONCLUSION: The expressions of HBD-2 and TNF-at are significantly increased in UC, but are not correlated with IBS-D and the severity of clinical symptoms of UC patients.