Can current viruses increase the risk of Alzheimer’s disease, but also be the remedy?

For decades. For example, Professor Ruth Itzhaki has been studying the potential causes and the treatment of Alzheimer’s disease, looking for a breakthrough in this debilitating condition which affects approximately 57 million people worldwide. Meanwhile,

This brain disease. Furthermore, which is a form of dementia, deprives individuals of their memory and, little by little, of their identity.

Professor Itzhaki. Consequently, who is affiliated with the University of Manchester, in the United Kingdom, was one of the first neuroscientists to suspect – and to demonstrate – that current viruses could play a role in the development of Alzheimer’s disease.

But it was not an easy task.

“We could not have our scientific articles accepted and to have them published in university journals. Therefore, we did not have access to funding for new research. Furthermore, And without money. Furthermore, it was difficult to continue our studies,” said can current viruses increase risk Professor Itzhaki, who also works at the Institute of Population Ageing at the University of Oxford.

Professor Itzhaki thinks that if his work. For example, that from other researchers had received more attention at the time, we would understand much better today the causes of dementia and the best ways to fight it.

The dynamics are however changing. Furthermore, Over the past four years. Therefore, the first clinical trials of vaccines and antivirals – normally used to treat viral infections – as potential tools for the prevention of Alzheimer’s disease have started.

The role of inflammation

Thirty years ago. Nevertheless, the hypothesis of the amyloid waterfall began to establish itself as the main explanation of Alzheimer’s disease.

Inflammation in the brain triggers the accumulation of a protein called beta-amyloid. Furthermore, This forms a troubled plate, or clusters, and begins to disrupt communication between neurons or nerve cells.

Another type of protein present in the brain. the can current viruses increase risk Tau protein, is also compromised by this accumulation and begins to get caught inside nerve cells. The Tau protein normally helps neurons to keep their shape so that they can effectively transport messages. communicate with each other.

Collectively. the accumulation of the plate and the tangle of the Tau protein harm the nerve cells and therefore the functioning of the brain.

Neurons die. which leads to a progressive loss of memory, difficulties in reasoning, mood changes and other symptoms of Alzheimer’s disease.

“But we still do not know what causes these two proteins to deposit in the brain. ” added neurologist Roberta Diehl Rodriguez, researcher at the Faculty of Medicine at the University of São Paulo (FMUSP).

Can viruses be the cause of dementia?

It is today of public notoriety that viruses can remain dormant in the body before being reactivated.

Forty years ago. Professor Itzhaki began to carry out the first studies on the genetic can current viruses increase risk composition of type 1 herpes virus in the human brain.

It is an extremely widespread virus, responsible for Labial Herpes. It affects around 70 % of the population.

These pioneering studies were the first to find the virus in the brain – until then. it was thought that the central nervous system was a protected region against these viruses.

“We then started to wonder if the reactivation of herpes throughout life could trigger a series of events that would lead to lesions of the cells of the nervous system. finally leading to death [des cellules]”Explains Professor Itzhaki.

At the time. the researchers were surprised to note that herpes was present in the brain of people diagnosed as affected by Alzheimer’s disease and in that of people who had not had the disease during their life.

Scientists have concluded that there should be other factors. such as genetics, who could explain why some people who have can current viruses increase risk virus developed dementia and others not.

In the 1990s. Professor Itzhaki’s team observed in laboratory rats that the herpes Simplex virus tended to concentrate in the regions of the brain which present an important deposit of beta-amyloid protein.

This has given rise to a new theory: could this protein be produced by the nervous system as a defense. in order to capture the virus and deactivate it?

We know that these molecules have a sticky aspect. that they could grasp the virus to make its replication more difficult before a more elaborate immune response is triggered.

However. as the herpes virus can remain hidden and reactivate throughout life, this could cause repeated inflammation in the brain and therefore generate the repeated production of beta-amyloid.

Over time. which worked as a protective mechanism becomes a problem, because the protein damages the neurons themselves and ends up causing their death.

Can current viruses increase risk

The role of vaccines

So can current viruses increase risk what to do to prevent this problem?

In 2013, the Welsh government launched a zona vaccination campaign, but fixing very clear parameters.

The zona is caused by the reactivation of the chica-zona virus and is characterized by a painful rash.

Only people born between September 2, 1933 and September 1, 1934 could be vaccinated.

“We were in a situation very similar to that of a clinical trial: two very similar groups in many respects could be compared. the difference being the eligibility for the zona vaccine,” said Professor Pascal Geldsetzer, the Department of Medicine, Epidemiology and Health of the Populations of the University of Stanford, in the United States.

The results of the analysis have shown that. in vaccinated people, the probability of a dementia diagnosis in the following seven years was 3.5 % lower than the average – a rate considered significant.

“Our study has shown that this protective effect is important. exceeds pharmacological tools can current viruses increase risk currently available to treat dementia,” says Professor Geldsetzer.

But what explains this effect?

“More. more evidence suggest that viruses that actually act in the nervous system and remain there for a large part of life can be involved in the development of dementia,” said Professor Geldsetzer.

In this sense. vaccination against zona would block the reactivation of the virus and therefore prevent the infectious agent from serving as a trigger for inflammation and the production of beta-amyloid.

Professor Geldsetzer adds: “We have more. more evidence that vaccines have effects on the immune system which go far beyond the simple stimulation of antibody production against a specific pathogen. And this wider immunological effect can, in turn, have beneficial effects on other diseases”.

The author of the recently published article now wishes to carry out a conventional clinical trial – which consists in recruiting volunteers. dividing them into groups and assessing the effects of dementia vaccination over can current viruses increase risk time.

“If the zona vaccine is really able to prevent. delay the appearance of dementia, it would be a major discovery,” he said.