Plasma interleukin-18 reflects severity of ulcerative colitis

AIM: The aim of this study was to evaluate the association between ulcerative colitis activity and plasma or mucosal concentrations of interleukin (IL)-18. METHODS: Il-18 concentrations were measured in plasma and mucosal samples from 15 patients with active ulcerative colitis (UC). RESULTS: The mean plasma concentration of IL-18 measured in all patients (422+/-88 pg/mL) doubled the mean value in healthy controls (206+/-32 pg/mL); however, the difference was not statistically significant. Plasma IL-18 levels revealed a significant positive correlation with scored endoscopic degree of mucosal injury, disease activity index, clinical activity index and C-reactive protein concentration. The mean concentration of plasma IL-18 was significantly higher in patients with severe ulcerative colitis (535+/-115 pg/mL) than in patients with mild ulcerative colitis (195+/-41 pg/mL), and in healthy controls. Although the mucosal mean IL-18 concentration in severe ulcerative colitis (2 523+/-618 pg/mg protein) doubled values observed in mild one (1 347+/-308 pg/mg protein), there was no statistically significant difference. CONCLUSION: Plasma IL-18 can be considered as a surrogate marker helpful in evaluation of ulcerative colitis activity.