Natural Killer Cell and Large Granular Lymphocyte Deficiency in the Gut of Children with Inflammatory Bowel Disease

The occurrence of natural killer cells and large granular lymphocytes(LGL) within the epithelium of colonic mucosa in children withinflammatory bowel disease (IBD) was compared to normal controls. Theirnumbers and localization within the epithelium from various regions of the colonwere analyzed with immunohistochemical techniques using fluorescent, lightand electron microscopy. The average number of natural killer cells and LGL innormal controls was 3.0±1.l per mn2. In contrast, there were no natural killercells in the gut epithelium of children with IBD, irrespective of disease activity,whether the biopsy specimens were obtained from involved or uninvolvedinflammatory regions of the gut, or the treatment status of the patients. However,the number of natural killer cells was normal in patients in remission withleft-sided colitis. The lack of natural killer cells and LGL in the gut epitheliumin children with IBD may be indicative of a possible genetic predisposition. Theauthors also present a new therapeutic strategy consisting of low dose interferon-alpha-2a that is efficacious in ameliorating ulcerative col iris and Crohn's diseaseand concomitantly increasing the number of natural killer cells and LGL in thegut