HISTOLOGIC-FINDINGS IN ISLETS OF WHOLE PANCREAS ALLOGRAFTS - LACK OF EVIDENCE FOR RECURRENT CELL-MEDIATED DIABETES-MELLITUS

Cell-mediated cytotoxicity directed toward pancreatic islets plays a s ignificant role in the pathogenesis of type 1 diabetes mellitus, Histo logically, autoimmune insulitis appears as mononuclear infiltrates tha t precede actual beta cell loss, Experimental studies by Bartlett et a l, on the BB rat model suggest that whole pancreas transplants are not susceptible to recurrent autoimmune diabetes, To test this hypothesis on clinical grounds, we evaluated the islets in pancreatectomies and percutaneous needle biopsies from 55 whole pancreas allografts. In thi s material, islet inflammation was never seen independently of allogra ft rejection, but was always associated with inflammation of the surro unding acinar structures. The degree of islet inflammation and the occ asional presence of islet necrosis correlated well with the degree of rejection and only occurred in the higher grades of the latter (grades III-V). We did not observe isolated insulitis as a histological indic ation of selective cell-mediated cytotoxicity against beta cells.