Immune system alterations in patients with inflammatory bowel disease during remission

OBJECTIVE: Perturbed immune homeostasis elicited by misbalanced production of proinflammatory and anti-inflammatory cytokines is characteristic of inflammatory bowel disease. The aim of this study was to evaluate cytokine profile in patients with different forms of inflammatory bowel disease - ulcerative colitis and Crohn's disease - during clinical remission phase. MATERIAL AND METHODS: Production of proinflammatory Th1 cytokines (tumor necrosis factor-alpha (TNF-alpha), interferon-gamma (IFN-gamma)) and anti-inflammatory Th2 cytokines (interleukin-10 (IL-10) and interleukin-13 (IL-13)) was analyzed in peripheral blood mononuclear cells of patients with inflammatory bowel disease (9 with ulcerative colitis and 9 with Crohn's disease) and control subjects (n=11) by enzyme-linked immunosorbent assay (two-site ELISA). RESULTS: The results of the study revealed that the level of TNF-alpha after stimulation with phytohemagglutinin in patients with Crohn's disease was significantly higher in comparison to both patients with ulcerative colitis and controls (P<0.001 and P<0.01, respectively). The secretion of IFN-gamma both in patients with Crohn's disease and ulcerative colitis was lower than that in controls (P=0.05 and P<0.01, respectively), but it normalized after stimulation with phytohemagglutinin. The levels of IL-10 and IL-13 were significantly (P<0.01) higher in patients with Crohn's disease than in patients with ulcerative colitis and control group before and after stimulation with phytohemagglutinin. CONCLUSIONS: The results of our study provide evidence that in patients with inflammatory bowel disease, the imbalance between production of proinflammatory Th1 and anti-inflammatory Th2 cytokines persists even during remission of the disease, and disturbances of immune homeostasis are significantly more expressed in patients with Crohn's disease than in patients with ulcerative colitis.