Is there a relationship between Alzheimer’s disease and infections?

The Challenge of Identifying a Link Between Alzheimer’s Disease and Infection: The Brain’s First Steps Towards a Better Treatment

The frequent absence of a concrete diagnosis in medical records is a challenge to various attempts to formulate a link between infection and Alzheimer’s disease. Accordingly, Geldsetzer’s studies have focused on dementia in general rather than Alzheimer’s specifically. “It’s not just that they’re poorly recorded, it’s that often they’re not easy to diagnose at all,” says Geldsetzer. As a result, it might well turn out that vaccination has broader neuroprotective benefits.

Scientists have a growing understanding of Alzheimer’s, and could lead to new avenues for treatment and prevention. A woman with a rare collection of genes has inspired some people to attack her. There are growing evidence that suggests a part in the development of Alzheimer’s. Researchers are trying to understand the mechanisms of disease progression between the sexes, which could lead to better care for all. However, this work now finds itself under threat in the United States, with some funding cuts ordered by President Donald Trump’s administration. The fight against Alzheimer’s disease is not safe.

Measuring antiviral antibodies circulating in the blood is also less than ideal, because they could be the result of viral reactivation anywhere in the body, not just the brain. It’s hard to find viruses in brain-tissue samples because it requires sensitive methods. The techniques for detecting viral particles in autopsy samples are the subject of some resistance to this research.

Tanzi thinks of the latter hypothesis. When you have a vaccine, you increase the peripheral immune system and monocytes enter the brain to clear amyloid, he says.

There are a number of reasons why the findings are suggestive, and why the efforts to link vaccination to protecting against Alzheimer’s can be difficult. Warren-Gash points out that dementia is often under-reported in health records — people with mild symptoms might be overlooked, which would skew the results of studies focused on dementia risk.

Since then, he and others have made a compelling case for the association of Alzheimer’s with a strong inflammatory response that suppresses neuronal function and accelerates the formation of amyloid-β plaques and tau tangles. Gwenn Garden, a doctor at the University of North Carolina at Chapel Hill, states that inflammatory mediators are present in the brain as soon as amyloid starts to accumulate. Some of this inflammation is a consequence of early plaque formation, which creates a feedback loop that accelerates further amyloid-β aggregation, but lifestyle and environmental factors might also create an inflammatory environment in the brain that favours the development of Alzheimer’s.

Shingles arises after the reactivation of the varicella zoster virus (VZV), which typically causes chickenpox early in life before becoming dormant for many decades. It is characterized by extremely painful rashes, but a growing number of clinicians and researchers have been uncovering evidence that VZV might also fuel the progression of Alzheimer’s disease and other forms of dementia.

The Future of Alzheimer’s Disease and its Diagnosis: The Challenges of Blood Testing and Genetic Testing in the Era of Precision Diagnostics

It can be hard to understand how hard a diagnosis of Alzheimer’s disease can be for an individual and a family. It is a sad fact that there are around seven million new cases of Alzheimer’s every year.

The first disease-modifying therapies for Alzheimer’s target the peptide amyloid-β, which clumps together in the brain. Clearing these deposits slows cognitive decline. The next step is to grow anti-amyloid therapy or combine it with drugs to target other parts of the disease.

A blood test that can differentiate Alzheimer’s from other forms of dementia was one of the major breakthrough of the past five years. There are concerns over their possible misuse, as the diagnostics look set to become crucial tools for physicians and researchers.

We are pleased to acknowledge the financial support of Eli Lilly & Company in producing this Outlook. Nature has the sole responsibility for all editorial content.