Original Article The Role of TNF-α and IL-2 in Ulcerative Colitis

Cytokines mediate tissue injury in various forms of colitis and play a key role in the pathogenesis of ulcerative colitis (UC) and are the most revealing of the immune defects found in inflammatory bowel disease (IBD). In this study we tried to clarify the role of interleukin-2 (IL-2) and tumour necrosis factor alpha (TNF-α) in ulcerative colitis in comparison to schistosomal colitis (SC) and non-specific colitis (NSC). The study was conducted on 56 patients. Group I included 30 patients with active UC. Group II included 16 patients with all other forms of colitis (including SC) and called the non-UC group. Ten patients with symptoms related to irritable bowel syndrome (IBS) and with normal colonoscopy served as control (group III). Cases underwent clinical, laboratory, endoscopic and histopathological assessment of colonic biopsies including immunohistochemical staining for TNF-α and IL-2. A higher expression of TNF-α in the UC group (group I) (100%) as compared to the non-UC group (group II) (62.5%) (p=0.01) was found. No significant difference of expression of IL-2 was detected between both groups (26% and 31%, respectively). On the other hand there was no expression of either cytokines in the control group (group III). Severity of TNF-α expression correlated with symptoms and histopathological changes of UC. TNF-α immunoreactivity is a significant feature of UC patients. The significant correlation of TNF-α with some clinical and histopathologic criteria of UC builds an important theory for the pathogenesis of UC and targets future therapy options of the disease.