Gut lavage IgG and interleukin 1 receptor antagonist: Interleukin 1 β ratio as markers of intestinal inflammation in children with inflammatory bowel disease

Abstract

Background - Whole gut lavage is currently used as preparation before radiological or endoscopic examination of the large bowel. Aim - To validate the gut lavage technique for the assessment of mucosal inflammation, by measuring intestinal IgG and interleukin 1β (IL-1β) in the fluid obtained. Patients - Sixteen children with Crohn's disease (CD), 14 with ulcerative colitis (UC), and 22 age matched controls. Methods - Isotonic, non-absorbable polyethylene glycol based lavage solution was given orally or by nasogastric tube. Clear fluid was collected, filtered, and treated with protease inhibitors. IgG, IL-1β and IL-1 receptor antagonist (IL-l-ra) were measured by sandwich enzyme linked immunosorbent assay (ELISA). Results - In patients with UC and CD, IgG and IL-1β levels were significantly (p<0-001) higher than in controls. A positive correlation (p<0.05) was found with disease activity scores. IL-l-ra levels were not significantly different in UC and CD, when compared with controls, but the IL-l-ra:IL-1β ratio was significantly (p< 0.01) lower in patients with UC and CD, and negatively (p<0-001) correlated with IgG levels in lavage fluid. Conclusions - Gut lavage fluid IgG and IL-1β levels and IL-1-ra:IL-1β ratio may provide objective discrimination between active and inactive disease in children with inflammatory bowel disease.