Summary: A recent study suggests that the Bacillus Calmette-Guérin (BCG) vaccine, which is commonly used to prevent tuberculosis, may also reduce the risk of Alzheimer’s disease and related dementias.
The study followed 6,467 individuals over 15 years after they were diagnosed with non-muscle-invasive bladder cancer. The results showed that patients who received the BCG vaccine had a 20% lower risk of Alzheimer’s disease and related dementias and a 25% reduced risk of death.
The team is now focusing on investigating the benefits of BCG vaccination in clinical trials related to Alzheimer’s disease.
Key facts:
- A study found that the BCG vaccine, commonly used for tuberculosis, was associated with a 20% reduced risk of Alzheimer’s disease and related dementias.
- The study, which included more than 6,400 individuals diagnosed with non-invasive bladder cancer, spanned 15 years.
- The BCG vaccine also demonstrated a 25% reduced risk of death in treated patients, with the protective association more pronounced in patients over 70 years of age.
source: Table general
The Bacillus Calmette-Guérin (BCG) vaccine—which prevents tuberculosis—offers multiple beneficial effects and is currently the recommended therapy for muscle-invasive bladder cancer.
In a new study led by researchers at Massachusetts General Hospital (MGH) and Brigham and Women’s Hospital (BWH), BCG vaccine treatment is associated with a reduced risk of Alzheimer’s disease and related dementias.
The findings are published in JAMA Network Open.
Although previous research has suggested an association between the BCG vaccine and a lower risk of dementia, the studies have been limited in size, study design, or analytical methods.
To conduct a more robust study, Mark Weinberg, MD, instructor of psychiatry at MGH, along with co-authors Colin Magdamo, BA, (MGH Neurology) and Afan Zafar, MD (MGH and BWH Urology), senior author Sudeshna Das, PhD, (MGH Neurology) and colleagues followed 6,467 individuals for up to 15 years after they were diagnosed with non-muscle-invasive bladder cancer.
Thus, BCG vaccine treatment is associated with a 25% lower risk of death. Credit: Neuroscience NewsThe group included 3,388 patients who underwent BCG vaccine treatment and 3,079 who served as controls matched for factors such as age, sex, and medical comorbidities.
During follow-up, 202 patients in the BCG vaccine group and 262 in the control group developed Alzheimer’s disease and related dementias.
The incidence was 8.8 per 1000 person-years and 12.1 per 1000 person-years in the respective groups. Analyzes show that BCG vaccine treatment is associated with a 20% lower risk of Alzheimer’s disease and related dementias. The protective association was greater in patients aged 70 years or older.
Additionally, during follow-up, 751 patients in the BCG vaccine group and 973 in the control group died. Thus, BCG vaccine treatment is associated with a 25% lower risk of death.
“A vaccine like BCG, if proven effective, is a perfect example of a cost-effective, population health-based solution to a devastating disease like Alzheimer’s,” Weinberg says.
“We are shifting our focus to studying the potential benefits of BCG vaccination of the elderly in clinical trials related to Alzheimer’s disease.”
If a causal relationship is found, it will be important to understand the mechanisms involved. Weinberg and colleagues note that the BCG vaccine’s effects on the immune system may play a role.
Additional co-authors include Sun Young Chung, BS; Wesley H. Chou, MD; Madhur Nayan, MD, PhD; Mayuresh Deodhar, MS; Daniel M. Frendl, MD, PhD; Adam S. Feldman, MD, MPH; Dennis L. Faustman, MD, PhD; Steven E. Arnold, MD; and Dr. Bela Vakulenko-Lagun.
Financing: This work was supported by the National Institutes of Health and the Alzheimer’s Association.
For this Alzheimer’s research news
Author: Brandon Chase
source: Table general
Contact: Brandon Chase – Mass General
Image: Image credited to Neuroscience News
Original Research: Free access.
“Association of BCG vaccine treatment with death and dementia in patients with non-muscle-invasive bladder cancer” by Marc Weinberg et al. JAMA Network Open
Summary
Association of BCG vaccine treatment with death and dementia in patients with non-muscle-invasive bladder cancer
Importance
BCG vaccine—used worldwide to prevent tuberculosis—provides multiple nonspecific beneficial effects, and intravesical BCG vaccine is currently the recommended treatment for non-muscle-invasive bladder cancer (NMIBC). In addition, BCG vaccine has been suggested to reduce the risk of Alzheimer’s disease and related dementias (ADRD), but previous studies have been limited by sample size, study design, or analyses.
Objective
To evaluate whether intravesical BCG vaccine exposure is associated with a reduced incidence of ADRD in a cohort of NMIBC patients, with death as a competing event.
Design, setting and participants
This cohort study was conducted in patients aged 50 years or older initially diagnosed with NMIBC between May 28, 1987 and May 6, 2021, treated within the Mass General Brigham Health System. The study included a 15-year follow-up of subjects (BCG vaccine-treated or controls) whose condition did not progress clinically to muscle-invasive cancer within 8 weeks and who did not have a diagnosis of ADRD in the first year after the diagnosis of NMIBC. Data analysis was conducted from April 18, 2021 to March 28, 2023.
Main outcomes and measures
The primary outcome was time to onset of ADRD identified using diagnosis and medication codes. Cause-specific hazard ratios (HRs) were estimated using Cox proportional hazards regression after adjustment for confounders (age, sex, and Charlson comorbidity index) using inverse weighting of probability scores.
Results
In this cohort study, including 6467 individuals initially diagnosed with NMIBC between 1987 and 2021, 3388 patients were treated with BCG vaccine (mean (SD) age, 69.89 (9.28) years; 2605 (76.9%) male) and 3079 served as controls (mean (SD) age, 70.73 (10.00) years; 2176 (70.7%) male). Treatment with BCG vaccine was associated with a lower rate of ADRD (HR, 0.80; 95% CI, 0.69-0.99), with an even lower rate of ADRD in patients aged 70 years or older by time of BCG vaccine treatment (HR, 0.74; 95% CI, 0.60-0.91). In a competing risks analysis, BCG vaccine was associated with a lower risk of ADRD (5-year risk difference, -0.011; 95% CI, -0.019 to -0.003) and a reduced risk of death in patients without a prior diagnosis of ADRD (5-year risk difference, -0.056; 95% CI, -0.075 to -0.037).
Conclusions and relevance
In this study, BCG vaccine was associated with a significantly lower incidence and risk of ADRD in a group of bladder cancer patients when death was considered as a competing event. Differences in risk vary over time, however.
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