Abstract
BACKGROUND/AIM: This study aims to explore the role of NF-kB p65/p50 expression in patients with inflammatory bowel disease (IBD), those with irritable bowel syndrome (IBS) and normal controls. PATIENTS AND METHODS: Twenty patients with IBS, 19 subjects with IBD and 18 normal controls, who underwent colonoscopy, provided us with biopsies from the terminal ileum, cecum and rectum. Patients with IBS were categorized according to bowel habits. Two polyclonal antibodies, alpha-p65 rabbit Ab and alpha-p50 rabbit Ab, were applied for immunohistochemical examination. RESULTS: It was found that in patients with IBD, the expression of intensity and distribution of NF-kB p65/p50 were lower than in IBS patients and normal controls (p>0.05), but the NF-kB p65/p50 ratio was elevated (p>0.05). The NF-kB p65/p50 ratio was lower than in IBD patients and rather similar to normal controls. The distribution of NF-kB p65 as well as the distribution and intensity of NF-kB p50 expression were higher in IBS patients with predominant diarrhea, and the difference was statistically significant in the cecum epithelium. The NF-kB p65/p50 expression ratio was higher in IBS patients with predominant diarrhea, but statistical significance was documented only in cecum epithelium specimens. CONCLUSION: The NF-kB p65/p50 ratio offers more significant information than each subunit. The increased expression of NF-kB p50 in IBS patients compared to IBD subjects or controls seems to be an early event in the process of inflammation. The similar pattern of NF-kB p65/p50 expression in IBS patients with predominant diarrhea and IBD patients may suggest possible common pathogenetic pathways.