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 factoralpha (TNF-a), interferon-gamma (IFN-g)) 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-a 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-g 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.