Preliminary experiments in a handful of people suggest that it might be possible to reverse Type 1 diabetes using an inexpensive vaccine to stop the immune system from attacking cells in the pancreas. Research in mice had already shown that the tuberculosis vaccine called BCG, prevents T cells from destroying insulin-secreting cells, allowing the pancreas to regenerate and begin producing insulin again, curing the disease.
Now tests with very low doses of the vaccine in humans show transient increases in insulin production, researchers will report Sunday at a San Diego meeting of the American Diabetes Assn. The Massachusetts General Hospital team is now gearing up to use higher doses of the vaccine in larger numbers of people in an effort to increase and prolong the response.
The findings contradict an essential paradigm of diabetes therapy — that once the insulin-secreting beta cells of the pancreas have been destroyed, they are gone forever. Because of that belief, most research today focuses on using vaccines to prevent the cells' destruction in the first place, or on using beta cell transplants to replace the destroyed cells.
The new findings, however, hint that even in patients with long-standing diabetes, the body retains the potential to restore pancreas function if clinicians can only block the parts of the immune system that are killing the beta cells.