Ulcerative colitis is an idiopathic chronic gastrointestinal disease characterized by chronic inflammation in the gastrointestinal tract. Cytokines may be responsible for immune responses, mucosal and tissue damage, and also a response to treatment in ulcerative colitis.

This case-control study aimed to investigate the relative gene expression of pro- and anti-inflammatory cytokines in a biopsy sample taken from the affected area in the colon of ulcerative colitis patients. The case group consisted of 23 patients suffering from treatment-resistant ulcerative colitis and the control group consisted of 24 ulcerative colitis patients who responded to treatment. Real-time PCR was performed to measure the gene expression levels of the pro-inflammatory cytokines including tumor necrosis factor-α (TNF-α), interferon-gamma (IFN-γ), interleukin-1β (IL-1β), IL-6, IL-8, IL-17A, IL-33, IL-35, and anti-inflammatory cytokines transforming growth factor-beta (TGF-β), IL-10, and IL-35. Finally, their interactions with serum levels of vitamin D were investigated.

The age; Mean (Std. dev.) in the control group was 45.88 (18.51) and in the case group was 41.30 (13.01). The results of the analysis of the expression of pro- and anti-inflammatory cytokines showed that there was no significant relationship between these cytokines and ulcerative colitis pathogenesis or response to treatment. Serum vitamin D did not correlate with pro-inflammatory or anti-inflammatory cytokines gene expression in biopsy samples.

In this study, there was no significant relationship between the expression of cytokines and ulcerative colitis, but from a clinical point of view, there was a significant difference in their expression in treated and resistant ulcerative colitis.