Cause of islet cell rejection discovered

The researchers at the Riken Institute and Fukuoka University said their discovery sets the stage for development of powerful new treatment techniques.

Currently, the most widely-used treatment for type 1 diabetes is the regular injection of insulin, the researchers said. While islet cell transplantation -- the transplantation of insulin-producing cells from a donor pancreas -- is a promising alternative approach, the scientists said the procedure has achieved only limited success due to a strong and rapid immune-mediated rejection of transplanted islets.

Now, in the new study, the researchers said they've demonstrated that HMGB1, a nuclear protein whose precise function has previously been unclear, is produced by the islet cells and directly triggers their early rejection.

Based on that finding, the scientists developed a system to measure the level of HMGB1 in the blood and determine the onset of rejection -- information they said they used to establish a treatment four times more effective than earlier islet transplantation protocols.

The study is reported in the Journal of Clinical Investigation.

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