Islet cells (islets of Langerhans) are clusters of cells inside the pancreas that produce insulin, the hormone required to move glucose (sugar) into cells for energy. The pancreas, an organ about the size of a hand, is located behind the lower part of the stomach.
Diabetes develops when the body doesn’t make enough insulin, cannot use insulin properly, or both, causing glucose to build up dangerously in the blood. Type 1 (juvenile onset) diabetes is an autoimmune disorder in which the body mistakenly attacks and destroys the islet cells of the pancreas. Children and young adults diagnosed with type 1 diabetes must carefully control their diet and take insulin daily to live. Type 2 (adult onset) diabetes usually begins with insulin resistance, a condition in which the body has difficulty using insulin effectively. Over time, insulin production declines and eventually many people with type 2 diabetes will also need to take insulin.
Islet transplant, the transplanting of healthy islet cells from an organ donor, may make it possible to replace insulin production and help people diagnosed with type 1 diabetes live without daily insulin injections. Other benefits of islet transplants that have been reported include a reduced need for insulin among recipients who still need insulin, improved blood glucose control, and greatly reduced risk of severe hypoglycemia episodes.