Einstein (São Paulo) (Dec 2005)
Human islet transplantation - state of the art
Abstract
Currently, only vascularized pancreas transplantation can reestablishlong-term normoglycemia but the scenario has beenassociated with significant morbidity and mortality. An attractivealternative that was clinically proposed approximately 25 yearsago is islet transplantation, because it avoids both major surgeryand complications related to exocrine enzymes. The aim of thisreview is to discuss why insulin-independence after isletallotransplantation has been so difficult to achieve. A literaturereview was undertaken using Medline from 1975 to October 2004.Results reported to the International Islet Transplant Registry upto December 2000 were also analyzed. Up to December 2000, 355islet allotransplants were reported to the Islet Transplant Registry.Of those accurately documented between 1990 and 2000 (n =355) only 19% (52/281) achieved insulin-independence (greaterthan 7 days). However with refined peritransplant protocols, insulinindependence can reach 11% (27/237) within one year. Howevermost of the studies describe single-donor transplants. Islettransplantation is a safe and effective strategy for betacellreplacement but many technical and scientific obstaclesremain. The first challenge is to obtain similar clinical successwith single-donor grafts; afterwards, to analyze which is the criticalislet mass to achieve insulin-independence and finally what arethe detrimental effects of transplanting islets in an ectopic site.Recent evidence from the Edmonton group demonstrated that isletallotransplatation still has the potential to become an establishedtreatment option for diabetic patients.
