Local and Systemic Liberation of Proinflammatory Cytokines in Ulcerative Colitis (original) (raw)

1999, Digestive Diseases and Sciences

Determination of plasma and tissue cytokinelevels in inflammatory bowel disease have frequentlyresulted in conflicting data. In the present study wedetermined in patients with ulcerative colitis (UC), the levels of the proinflammatory cytokinesinterleukin (IL)-1β, IL-6, interferon(IFN)-γ, and tumor-necrosis factor (TNF)-αliberated by peripheral blood mononuclear cells (PBMC)and lamina propria mononuclear cells (LPMC) after 48-hrculture with pokeweed mitogen (PWM). IL-1β, IL-6,IFN-γ and TNF-α in the supernatant weredetected by ELISA. Results show low basal levels ofIL-1β secretion by PBMC and LPMC, and a considerableincrease after mitogen stimulation. Basal IL-6production by PBMC was higher in UC patients than incontrols [2029 pg/ml, CI9 (–165 to4223) vs 572 pg/ml (–383 to 1527) respectively, P = 0.05] and also afterPWM activation [14,995 pg/ml (7759 -22230) vs 6598 pg/ml(3240-9956), respectively, P = 0.05]. In LPMC, nodifferences in IL-6 secretion were observed. TNF-α in activated PBMC of patients with UC was notsignificantly increased in relation to control (P =0.09). No constitutive secretion of IFN-γ wasobserved in mononuclear cells. IFN-γ levelssecreted by activated LPMC were lower in patients withUC than in controls [1571 pg/ml (–108 to 3251) vs7953 pg/ml (3851-12,055), respectively, P = 0.03]. Theseresults suggest that IL-6, IL-1β, and TNF-α participate as mediators in the inflammatoryphenomena observed in UC. Further studies are necessaryto evaluate the role of IFN-γ in thiscondition.