Tuberculosis Vaccine a New Drug to Fight Type 1 Diabetes

A study conducted at the Harvard University suggests that the TB vaccine that has been in use for 90 years, may help reverse type 1 diabetes and eliminate the lifelong need for insulin.  Though there is no guarantee about the results from this early stage trial, it will stand up in larger studies, which are under way.

The study published Wednesday in the journal PLoS One, found that the vaccine already approved for tuberculosis can kill the autoimmune cells that are active players in type 1 diabetes.

Every year the disease affects as many as 3 million Americans and around 30,000 people in the United States, half of them adults, are diagnosed with the disease, which has long been considered incurable.

According to the study, people suffering from type 1 diabetes inject themselves with insulin daily in order to control their blood sugar, as their bodies don't produce it. This is due to a weak immune system that damages the insulin-producing cells in the pancreas. Researchers discovered that the vaccine BCG (bacillus Calmette-Guerin) stimulated the production of a protein that destroys the insulin-attacking cells. Denise Faustman, M.D., PhD, of Harvard, and colleagues measured this by C-peptide levels.

BCG, a generic vaccine, stimulates innate immunity by inducing the production of TNF, which kills the autoimmune T lymphocytes that destroy insulin-secreting pancreatic beta cells -- those that cause type 1 diabetes -- while leaving healthy T cells unharmed. TNF at high doses, however, causes systemic toxicity. They opted for an alternative approach with a Food and Drug Administration-approved vaccine that can induce TNF by triggering the innate immune response.

Researchers conducted a proof-of-concept study in patients with longstanding type 1 diabetes. The mean age of patients was 35.

They administered two doses of the BCG vaccine to three patients who had been diagnosed with type 1 diabetes. Researchers followed the patients for 20 weeks and found that two of the three had an increase in the death of the insulin-harming cells and a rise in the elevation of C-peptide levels, suggesting the production of insulin.

The researchers are working to introduce this vaccine into the market. They concluded saying, "The paper shows that BCG is associated with a transient improvement in a couple of patients, but it's hard to conclude that TNF is the causative factor."