The bone marrow as a potential receptor site for pancreatic islet grafts.

BACKGROUND: Pancreatic islet transplantation in the human liver is being performed with increasing success to treat diabetes. However, the liver as a receptor site has many drawbacks due to immunological and non-immunological factors as well as important technical limitations. Bone marrow offers an easily accessible extrahepatic receptor site. Therefore, we attempted to explore the survival of pancreatic islets transplanted into the bone marrow of rats.
METHODS: Pancreatic islets islografts and allografts were implanted into the bone marrow of rats. No immunosuppression was used. Morphology, presence of insulin, and glucagon and signs of apoptosis and rejection were explored.
RESULTS: Pancreatic islets can be successfully engrafted into the bone marrow of rats, maintaining a normal histological appearance in insulin and glucagon content and no signs of apoptosis or rejection.
CONCLUSIONS: These preliminary findings suggest that the bone marrow is capable of maintaining pancreatic islets in the absence of immunosuppression and, thus, can constitute an immunoprivileged environment for engraftment.