Bacillus Calmette-Guerin (BCG) Vaccine Impact on Dementia Risk in Bladder Cancer Patients: A Systematic Review and Meta-Analysis.

BACKGROUND: The BCG vaccine has been traditionally administered to prevent TB. It has been additionally used in bladder cancer patients as a therapy with success. Some observational studies found that bladder cancer patients receiving BCG may have reduced dementia risk, however, the evidence is not conclusive. OBJECTIVE: To investigate the impact of BCG vaccine on dementia risk in bladder cancer patients. METHODS: Six databases were searched from inception to January 13, 2024, for published and unpublished studies that examine the association between BCG and dementia risk in bladder cancer patients. We conducted meta-analyses using a random-effects model. RESULTS: Eight retrospective cohort studies were included in the systematic review and seven in the meta-analyses. Because there were studies with overlapping populations, two separate main analyses were performed reassuring the avoidance of overlap. The first analysis showed that compared to controls, BCG did not reduce dementia risk [5 studies pooled, n=88,852, HR = 0.65, 95% CI (0.40, 1.06), I2 = 85%] whereas there was a marginally significant risk reduction in the second analysis [6 studies pooled, n=70,025, HR = 0.63, 95% CI (0.40, 0.97), I2 = 83%]. Sensitivity analysis excluding the unpublished studies did not affect the outcome importantly. Additional meta-analysis showed that BCG did not reduce the risk of Alzheimer's disease. CONCLUSION: This meta-analysis of observational studies found that BCG administration in bladder cancer patients has likely a minimally positive impact on dementia risk if any. To better understand the effect of BCG on dementia, randomized controlled trials are needed.

Relevance of cerebrospinal fluid findings in patients with multiple sclerosis and seizures.

Seizures occur 2-3 times more frequently in Multiple Sclerosis (MS) patients compared to the general population. The prevalence of seizures is reported to be 1.5-7.8% in MS population. However, it is unclear if seizure is an indirect symptom of neuroinflammation in MS. In our study, we explored the relevance of cerebrospinal fluid (CSF) findings in this unique patient cohort with MS and seizures. We retrospectively reviewed the charts of 32 MS patients with subsequent seizures (MSSS) and 12 patients with seizures followed by MS (SFMS). These two study groups were compared with two control groups - MS without seizures (MSNOS) and seizures without MS (SNOMS). Clinical characteristics and CSF findings between these groups were compared using boot strapped independent t-test. The CSF lymphocyte percentage of the SFMS group (95.6 ±â€¯3) was significantly higher compared to MSNOS (66.0 ±â€¯36.9, p = .04) and SNOMS (81.7 ±â€¯10.0, p = .03). The CSF IgG index was significantly higher in SFMS group (1.9 ±â€¯1.2, p = .02) as compared to MSSS group (0.99 ±â€¯0.4). Patients with seizures as initial symptom of MS may have higher degree of CNS inflammation. Nonspecific clinical symptoms and atypical imaging findings in patients presenting with seizures may warrant close monitoring for development of MS.