CD8-CELLS ANALOGOUS TO INTESTINAL INTRAEPITHELIAL LYMPHOCYTES INFILTRATE THE PANCREAS IN CHRONIC-PANCREATITIS(CD103+ T)

Objective: Chronic pancreatitis is a painful chronic inflammatory dise ase of the exocrine pancreas that is associated with the replacement o f functional parenchyma by extended fibrosis and with a massive infilt ration of T lymphocytes. However, to date further characterization of infiltrating T cells in chronic pancreatitis has not been undertaken. Methods: Using the novel method of multiepitope imaging with fluorochr ome-tagged specific monoclonal antibodies, which allows the simultaneo us localization and characterization of T cells in tissues, we analyze d the distribution and phenotypes of T cells infiltrating the pancreas in chronic pancreatitis. Results: The mean CD4:CD8 ratio in 10 cases of chronic pancreatitis was 2.4:1. In order of decreasing frequency, t he following markers were observed: CD45RO, CD18, TCR gamma delta, and CD103. The lymphocytes, especially of the CD4+ subset, were found mai nly in the fibrous stroma, but T cells were also observed periductally . A T-cell subset bearing the phenotype CD8+CD103+, analogous to intes tinal intraepithelial lymphocytes, was found intracalating between the cells of the ductal epithelium, Conclusions: Phenotyping of the T lym phocytes in chronic pancreatitis supports the concept of the involveme nt of cell-mediated cytotoxicity in the pathogenesis of this disease; In addition, intraepithelial lymphocytes were found interspersed betwe en the ductal epithelial cells, pointing to a role of this T-cell subs et as a first-line defense against deleterious epithelial events in ch ronic pancreatitis. (C) 1998 by Am. Cell. of Gastroenterology.