Invited commentary: an overview of pancreas transplantation--biologic aspects.

The clinical results of vascularized pancreas transplants have improved somewhat during the last 5 years, the but technical problems of handling the pancreatic duct remain difficult. Clinical isolated islet allografts have rarely if ever succeeded. Rejection appears to be a more severe problem in pancreas or islet transplants than in other pancreas transplants. Nevertheless, if nonendocrine cells can be completely removed, transplanted beta-cells might have prolonged survival, since they probably lack Ia antigens that may be necessary to evoke an immune response. An additional biologic problem is the possible destruction (independent of rejection) of transplanted islet cells by autoimmune insulitis. This has been found to occur in spontaneously diabetic rats who received transplanted islets. Study of this animal model may provide important clues to the etiology and treatment or prevention of diabetes.