Phenotypic and functional characteristics of colonic lymphocytes isolated from patients with primary sclerosing cholangitis and inflammatory bowel disease.

Because primary sclerosing cholangitis (PSC) frequently is associated with inflammatory bowel disease, the phenotypic and functional characteristics of lymphocytes isolated from colonic mucosa were studied in patients with primary sclerosing cholangitis (PSC), patients with ulcerative colitis and patients with other colonic and hepatic disorders. To accomplish this, lymphocytes isolated from colonic biopsies obtained at the time of colonoscopy were expanded in vitro in the presence of interleukin 2 (IL2). Cell propagation was similar in patients with PSC with or without associated inflammatory bowel disease but was diminished significantly when compared to results obtained in patients with ulcerative colitis not associated with PSC. The CD4:CD8 ratio of the propagated lymphocytes was increased in patients with PSC compared to controls. The Leu 19+ subset of cells was also increased in PSC patients. In patients with inflammatory bowel disease, increased cytotoxicity was noted at low effector to target cell ratios with SK-HEP (hepatocellular carcinoma) but not RPMI 7451 (cholangiocarcinoma) targets. No differences between PSC patients and controls were observed for NK sensitive and NK resistant targets. Based upon these studies it can be concluded that: 1) expansion of lymphocytes obtained from endoscopic colonic biopsies using recombinant IL2 represents an alternative method by which intestinal lymphocytes can be studied; 2) natural killer cells are increased in the colonic mucosa of patients with primary sclerosing cholangitis; 3) colonic cytotoxic T lymphocytes may be more active in patients with chronic liver disease and particularly those with associated inflammatory bowel disease.