Summary: The Bacillus Calmette-Guérin (BCG) vaccine, commonly used to innoculate against tuberculosis and as a bladder cancer treatment, also appears to reduce the development of Alzheimer’s disease.
Source: Hebrew University of Jerusalem
Holidays are a time for family. Festive gatherings with parents, grandparents, aunts and uncles create memories that last a lifetime. But when a loved one has Alzheimer’s disease (AD), holidays often become painful reminders of loss and deterioration. Currently, Alzheimer’s affects one-in-ten adults over the age of 65–a number that is expected to triple by 2030. The need to find a cure is great.
Now there may be a glimmer of hope. A research team headed by Hervé Bercovier, Charles Greenblatt and Benjamin Klein at the Hebrew University of Jerusalem (HU)’s Department of Microbiology and Molecular Genetics has discovered that the Bacillus Calmette-Guérin (BCG) vaccine, originally developed for tuberculosis and commonly used to treat bladder cancer, may also be an effective treatment to prevent Alzheimer’s. They published their findings in PLOS ONE.
“There’s data reaching back to the 1960’s that shows that countries treating bladder cancer patients with the BCG vaccine had a lower prevalence of Alzheimer’s disease but it hadn’t been properly analyzed,” shared lead author Bercovier.
Until now. Bercovier and his team followed 1,371 bladder cancer patients receiving treatment at HU’s Hadassah Medical Center. The average patient age was 68. During follow-up visits, 65 cancer patients had developed Alzheimer’s. Those who had not received BCG as part of their treatment had a significantly higher risk of developing Alzheimer’s than did BCG-treated patients: 8.9% (44 patients) as opposed to 2.4% (21). Further, when compared with the general (healthy) population, people who had never been treated with BCG had a 4-fold higher risk for developing Alzheimer’s than did those who were treated with BCG.
It’s important to note that the researchers have not developed a vaccine that prevents Alzheimer’s. However, shared Bercovier “our study is an important step towards understanding the ways in which our immune system is a major player in the pathogenesis of Alzheimer’s and how the BCG vaccine, which modulates the immune system, may serve as an effective preventative treatment to this crippling condition.”
And that would be the best holiday gift of all.
Hebrew University of Jerusalem
Tali Aronsky – Hebrew University of Jerusalem
The image is in the public domain.
Original Research: Open access
“Bacillus Calmette-Guérin (BCG) therapy lowers the incidence of Alzheimer’s disease in bladder cancer patients”. Hervé Bercovier et al.
PLOS ONE doi:10.1371/journal.pone.0224433.
Bacillus Calmette-Guérin (BCG) therapy lowers the incidence of Alzheimer’s disease in bladder cancer patients
Alzheimer’s disease (AD) affects one in ten people older than 65 years. Thus far, there is no cure or even disease-modifying treatment for this disease. The immune system is a major player in the pathogenesis of AD. Bacillus Calmette-Guérin (BCG), developed as a vaccine against tuberculosis, modulates the immune system and reduces recurrence of non-muscle invasive bladder cancer. Theoretical considerations suggested that treatment with BCG may decrease the risk of AD. We tested this hypothesis on a natural population of bladder cancer patients.
Methods and findings
After removing all bladder cancer patients presenting with AD or developing AD within one-year following diagnosis of bladder cancer, we collected data on a total of 1371 patients (1134 males and 237 females) who were followed for at least one year after the diagnosis of bladder cancer. The mean age at diagnosis of bladder cancer was 68.1 years (SD 13.0). Adjuvant post-operative intra-vesical treatment with BCG was given to 878 (64%) of these patients. The median period post-operative follow-up was 8 years. During follow-up, 65 patients developed AD at a mean age of 84 years (SD 5.9), including 21 patients (2.4%) who had been treated with BCG and 44 patients (8.9%) who had not received BCG. Patients who had been treated with BCG manifested more than 4-fold less risk for AD than those not treated with BCG. The Cox proportional hazards regression model and the Kaplan-Meier analysis of AD free survival both indicated high significance: patients not treated with BCG had a significantly higher risk of developing AD compared to BCG treated patients (HR 4.778, 95%CI: 2.837–8.046, p = 4.08×10-9 and Log Rank Chi-square 42.438, df = 1, p = 7.30×10-11, respectively). Exposure to BCG did not modify the prevalence of Parkinson’s disease, 1.9% in BCG treated patients and 1.6% in untreated (Fisher’s Exact Test, p = 1).
Bladder cancer patients treated with BCG were significantly less likely to develop AD at any age than patients who were not so treated. This finding of a retrospective study suggests that BCG treatment might also reduce the incidence of AD in the general population. Confirmation of such effects of BCG in other retrospective studies would support prospective studies of BCG in AD.