Assessment of Insulin Production From Native Pancreas in Patients With Pancreas Transplants

Study Summary

This study will examine whether insulin-producing cells in the pancreas (beta cells) can recover in patients with type 1 diabetes who have had a pancreas transplant. In type 1 diabetes, the body's immune system destroys the beta cells. Patients are treated with insulin shots or a pancreas transplant to control their blood sugar. Some experiments suggest that the pancreas may have the capacity to recover some of its insulin-producing capacity, but that ability is negated by factors such as the continuing immune attack and erratic blood sugar levels in patients. Patients who have had a pancreas transplant may be in a unique situation to allow their own pancreas to regrow beta cells for two reasons: 1) the medicines they take to prevent rejection of the transplanted pancreas weaken their immune system; and 2) they have near-normal blood sugar levels because of their functioning transplanted pancreas. This study will test this hypothesis by sampling blood from patients' hepatic vein, which drains the liver and native pancreas and from their iliac vein, which drains the transplanted pancreas. This will determine whether insulin is coming from the transplanted pancreas (iliac vein) or the liver and native pancreas (hepatic vein). Patients 18 years of age and older who have had stable pancreatic transplant function for more than 5 years may be eligible for this study. Candidates are screened with a medical history and physical examination. Participants are admitted to the hospital for 2 days for a full medical examination, blood tests and procedures to determine insulin production. The procedures will include the placement of catheters in the neck and groin for blood sampling. Participants will be closely monitored after the procedures and discharged home if there are no complications.