Tuberculosis vaccine could reverse... type 1 diabetes
The BCG vaccine against tuberculosis can reverse type 1 diabetes to almost undetectable levels, an eight-year study suggests.
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| Vaccines could mean diabetics no longer need to regularly check their blood sugar. |
The new study included 52 people with type 1 diabetes. After three years of treatment, average blood sugar levels dropped by 10 percent and by 18 percent after four years. Those on treatment had an average blood sugar reading of 6.65, close to the 6.5 level considered the cutoff for diagnosing diabetes.
Meanwhile, the placebo group's blood sugar levels continued to increase during the trial period.
Commenting on the research, Professor Helen McShane, Department of Virology, University of Oxford, said: “The finding that two doses of BCG, a safe vaccine that is almost 100 years old, can significantly improve blood sugar control in patients with type 1 diabetes is remarkable.
“This study provides data supporting a plausible immunological mechanism for this sustained effect, and adds to the growing knowledge of the effects of BCG on autoimmune diseases.
“The effects observed here, which increase over time, could provide a cost-effective way to reduce the significant morbidity and mortality associated with this disease.”
If this is proven to work it would be a “major advance”, said Professor Andrew Hattersley FRS, professor of molecular medicine at the University of Exeter Medical School.
Professor Daniel Davis, University of Manchester, said: “The number of patients studied here is quite small but the research points to a very interesting and important way in which the strength of our immune system can be modulated by the BCG vaccine.”
"Further studies should, and are, being done to definitively determine whether or not this approach is helpful for patients with type I diabetes, and even other autoimmune diseases."
British experts have hailed the results as “very exciting” and added that if the simple and safe vaccine has a similar impact in larger trials, it would be a “major advance” in the treatment of type 1 diabetes.
“This is clinical demonstration of the ability to consistently lower blood sugar to near-normal levels with a safe vaccine, even in patients with long-standing conditions,” said Dr. Denise Faustman, who led the trial at Massachusetts General Hospital.
“In addition to the clinical results, we have gained insight into the mechanisms through which limited doses of BCG vaccine can induce permanent, beneficial changes in the immune system and lower blood sugar in type 1 diabetes.”
Used for nearly a century to prevent tuberculosis, the BCG vaccine boosts and modulates the immune system. The team also found that vaccination speeds up the rate at which cells convert glucose into energy, and tests on mice suggest that the vaccine may also be beneficial in fighting type 2 diabetes.
Diabetes
Type 1 diabetes
It occurs when the pancreas (a small gland behind the stomach) does not produce insulin – a hormone that regulates blood sugar levels. If blood sugar levels are too high, it can gradually damage the body's organs.
Only 10% of people with diabetes have type 1, but it is the most common type of diabetes in children.
Type 2 diabetes
The body does not produce enough insulin to function properly, or the body's cells do not respond to insulin. This means that glucose remains in the blood and is not used for energy.
90% of adults have type 2 diabetes and the disease tends to develop late in life.
Gestational diabetes
About 1 in 20 pregnant women will develop blood sugar levels so high that their bodies cannot produce enough insulin to metabolise them. This condition needs to be managed during pregnancy but almost always goes away after giving birth.