Islet transplantation is a medical procedure that treats type 1 diabetes by implanting isolated cells from a donor pancreas into another person. The primary goal of this treatment is to restore the body’s ability to produce its own insulin, helping to regulate blood glucose levels. This approach offers a potential pathway for individuals with type 1 diabetes to reduce or even eliminate their reliance on external insulin injections.
Understanding Pancreatic Islets and Their Role
Pancreatic islets, often called islets of Langerhans, are small clusters of cells scattered throughout the pancreas. These specialized cells produce several hormones, with insulin being one of the most prominent. Insulin acts as a key, allowing glucose from the bloodstream to enter cells for energy or storage, which helps maintain stable blood sugar levels.
In type 1 diabetes, the body’s immune system mistakenly attacks and destroys the beta cells within these pancreatic islets. This autoimmune destruction leads to a severe deficiency or complete absence of insulin production. Without sufficient insulin, glucose accumulates in the blood, leading to high blood sugar levels and various health complications.
The Islet Transplantation Process
The islet transplantation process begins with obtaining a pancreas from a deceased organ donor. Specialized enzymes are then used to separate and purify the islets from the rest of the pancreatic tissue. The preparation is checked for quality and sterility before transplantation.
Once the islets are prepared, they are infused into the recipient’s liver through the portal vein. This minimally invasive procedure involves inserting a catheter through a small incision, guided by imaging techniques. The islets are then delivered into the liver, where they are expected to establish new blood vessel connections and begin producing insulin.
Candidate Eligibility for Islet Transplantation
Islet transplantation is considered for a select group of individuals with type 1 diabetes. Candidates experience severe complications despite diligent insulin therapy, such as frequent episodes of severe hypoglycemia (very low blood sugar) or an inability to recognize when their blood sugar is dangerously low, known as hypoglycemia unawareness. These situations pose risks, including seizures, loss of consciousness, or even death.
Beyond the severity of diabetes complications, general health requirements are also considered. Patients need to be free of other severe, untreatable heart or lung diseases, active cancer, or uncontrolled infections. Individuals who require a very high daily insulin dose might not be suitable candidates.
Living with an Islet Transplant
After an islet transplant, recipients may experience improvements in blood glucose control, with many achieving insulin independence or a substantial reduction in their daily insulin needs. Many recipients may remain insulin independent five years after the procedure. This improved control can also help prevent or slow the progression of long-term diabetes complications affecting the heart, kidneys, nerves, or eyes.
Living with an islet transplant requires lifelong immunosuppressive medication. These medications prevent the recipient’s immune system from rejecting the transplanted islets. While these drugs are effective, they can have side effects, including mouth ulcers, anemia, swelling, high cholesterol, liver problems, high blood pressure, and an increased risk of infections. Regular monitoring and follow-up care are also required to track islet function, manage medication side effects, and address any potential complications, such as the need for repeat infusions if islet function declines over time.