Markers Detect Recurrent Autoimmunity in Organ Transplant Patients
Preliminary studies conducted by the DRI suggest type 1 diabetes patients who have undergone a simultaneous pancreas/kidney (SPK) transplant may eventually lose function because of recurrent autoimmunity - the immune system process that initally caused diabetes. Until now, it was thought immunological failure in transplant patients was primarily the result of organ rejection.
The same study suggests, however, that we can predict the recurrent autoimmunity, which opens the door for the development of new strategies to prevent the recurrence. The findings are part of a broader study that has been published in the journal Diabetes.
The study was conducted by DRI scientists in collaboration with the University of Miami/Jackson Memorial Hospital Transplant Institute and researchers at the Benaroya Research Institute. In the study, researchers identified three SPK transplant patients who began to lose their ability to secrete insulin 5 - 9 years after transplant. The researchers found that in those patients, autoimmune diabetes had recurred. The immune system began to again mistakenly destroy the cells in the pancreas which produce insulin, even though the patients were on chronic immunosuppression and showed no clinical signs of organ rejection.
The results are significant because they demonstrate that immunosuppression, while it prevents transplant rejection, does not stop autoimmunity from eventually recurring. In fact, ongoing studies suggest that recurrent autoimmunity may explain about 50 percent of the immunological failures after SPK transplants.
Fortunately, the same study demonstrated that specific immune activation markers may, in the future, help predict the onset of recurrent autoimmunity in transplant patients who have received either islets or a whole pancreas. In the SPK transplant patients studied, our researchers found markers -- diabetes-associated autoantibodies and autoreactive lymphocytes -- prior to or near the time of diabetes recurrence. Our scientists are now using these as markers to identify transplant patients at risk for the development of recurrent diabetes. DRI scientists can also use the immune markers to monitor the impact of new strategies to address recurrent diabetes.