IL-8as an important chemoattractant forneutrophils in ulcerative colitis andCrohn'sdisease

SUMMARY IL-8isgenerating increasing interest as a powerful neutrophil chemoattractant andactivator. To elucidate themechanisms ofneutrophil infiltration ininflammatory boweldisease, we examined 33 patients withulcerative colitis (UC),18withCrohn's disease (CD),eight withsome other typeof colitis, and18normalcontrol subjects formeasurementofIL-8inhomogenates ofcolonic biopsy specimens. Theaffected colonic mucosa was found tocontain significantly more IL-8inpatients with active inflammatory boweldisease thaninpatients withinactive disease (UC,P<0-001;CD, P< 0-001), inpatients withother typesofcolitis (UC,P< 005;CD,P < 0-01), or innormalcontrol subjects (UC,P<0-001; CD,P<0-001). Colonic IL-8levels correlated significantly withthe macroscopic gradeoflocal inflammation, especially inpatients withUC (P<0-001). Colonic IL-8 levels alsocorrelated wellwiththeneutrophil numbers inmucosal tissue (UC,r= 0-950, P<0-001; CD,r= 0940,P< 0-001), andwithcolonic IL-1I(r = 0-91 1,P< 0-001) andtumournecrosis factoralpha (TNF-a) levels (r = 0-604, P< 0-001 )inpatients withthese twoconditions. These data suggest a potential roleforIL-8anditsregulatory cytokines IL-1andTNF-ainmediating neutrophil infiltration ofthegutwallininflammatory boweldisease.