(HealthDay News) – A tuberculosis vaccine can reduce autoimmunity and increase insulin production in patients with long-term type 1 diabetes, according to a study published online Aug 8 in PLoS One.
Building on previous studies in rodents showing that the Bacillus Calmette-Guerin (BCG) vaccine stimulates tumor necrosis factor production and stimulates innate immunity, Denise L Faustman, MD, PhD, from Massachusetts General Hospital in Boston, and colleagues randomly assigned six patients with long-term type 1 diabetes to BCG or placebo. Results were compared with six healthy controls as well as an additional 57 patients with type 1 diabetes and 16 healthy subjects.
The researchers found that, after 20 weeks, diabetes patients treated with BCG, as well as one healthy control who became infected with Epstein-Barr virus (EBV) after enrollment, had increased numbers of dead insulin-autoreactive T cells and induction of regulatory T cells. Levels of C-peptide, a measure of insulin production, also significantly and transiently increased in two BCG-treated diabetes patients and the EBV-infected healthy subject.
“We conclude that BCG treatment or EBV infection transiently modified the autoimmunity that underlies type 1 diabetes by stimulating the host innate immune response,” Faustman and colleagues write.