Oct 20, 2014

Cold Sores (Herpes Simplex Virus) Increase the Risk of Dementia

The only thing I can say is my mother lived with Alzheimer's disease, and she was getting cold sores in her mouth for as long as I could remember. This research indicates there is a connection between cold sores and the risk of dementia.

By Alzheimer's Reading Room

Infection with herpes simplex virus increases the risk of Alzheimer's disease.

Cold Sores (Herpes Simplex Virus) Increase the Risk of Dementia

Researchers at Umeå University, Sweden, claim this in two studies in the journal Alzheimer's & Dementia.
"Our results clearly show that there is a link between infections of herpes simplex virus and the risk of developing Alzheimer's disease. This also means that we have new opportunities to develop treatment forms to stop the disease," says Hugo Lövheim, associate professor at the Department of Community Medicine and Rehabilitation, Geriatric Medicine, Umeå University

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Cold sores increase the risk of dementia

Alzheimer's disease is the most common among the dementia diseases.

In recent years research has increasingly indicated that there is a possible connection between infection with a common herpes virus, herpes simplex virus type 1, and Alzheimer's disease.

A majority of the population carries this virus.

After the first infection the body carries the virus throughout your lifetime, and it can reactivate now and then and cause typical mouth ulcer.

The hypothesis which links the herpes virus and Alzheimer's disease is based on that a weakened immune system among the elderly creates opportunities for the virus to spread further to the brain. There this can in turn start the process which results in Alzheimer's disease.

Hugo Lövheim and Fredrik Elgh, professor at the Department of Virology, have now confirmed this link in two large epidemiological studies.

In one study, which is based on the Betula project, a study on ageing, memory and dementia, the researchers show that a reactivated herpes infection doubled the risk of developing Alzheimer's disease.

This study had 3,432 participants who were followed for 11.3 years on average.

In another study, samples donated to the Medical Biobank at Umeå University from 360 people with Alzheimer's disease were examined and as many matched people who had not developed dementia.

The samples were taken on average 9.6 years before diagnosis. This study showed an approximately doubled risk of developing Alzheimer's disease if the person was a carrier of the herpes virus.
"Something which makes this hypothesis very interesting is that now herpes infection can in principle be treated with antiviral agents. Therefore within a few years we hope to be able to start studies in which we will also try treating patients to prevent the development of Alzheimer's disease," says Hugo Lövheim
Read the studies in Alzheimer's & Dementia

Reactivated herpes simplex infection increases the risk of Alzheimer's disease 
http://www.ncbi.nlm.nih.gov/pubmed/25043910

Abstract

Background
Previous studies have suggested a link between herpes simplex virus (HSV) type 1 and the development of Alzheimer's disease (AD).

Methods
The present analysis included 3432 persons (53.9% women, mean age at inclusion 62.7 ± 14.4 years) with a mean follow-up time of 11.3 years. The number of incident AD cases was 245. Serum samples were analyzed for anti-HSV antibodies (immunoglobulin (Ig)G and IgM) by enzyme-linked immunosorbent assays.

Results
The presence of anti-HSV IgG antibodies was not associated with an increased risk for AD, controlled for age and sex (hazard ratio, HR, 0.993, P = .979). However, the presence of anti-HSV IgM at baseline was associated with an increased risk of developing AD (HR 1.959, P = .012).

Conclusion
Positivity for anti-HSV IgM, a sign of reactivated infection, was found to almost double the risk for AD, whereas the presence of anti-HSV IgG antibodies did not affect the risk.

Author information -- Lövheim H1, Gilthorpe J2, Adolfsson R3, Nilsson LG4, Elgh F5.


Herpes simplex infection and the risk of Alzheimer's disease—A nested case-control study
http://www.alzheimersanddementia.com/article/S1552-5260(14)02770-8/abstract

Abstract

Background
Herpes simplex virus (HSV) is thought to play an etiological role in the development of Alzheimer's disease (AD).

Methods
Plasma samples from 360 AD cases (75.3% women, mean age 61.2 years) and 360 age- and sex-matched dementia-free controls, taken on average 9.6 years before AD diagnosis, were analyzed for anti-HSV antibodies (immunoglobulin G, IgG, and immunoglobulin M, IgM) by enzyme-linked immunosorbent assays.

Results
In the complete sample group, the presence of anti-HSV IgG and IgM antibodies did not increase the risk of AD significantly (odds ratio (OR) 1.636, P = .069 and OR 1.368, P = .299, respectively). In cases with 6.6 years or more between plasma sampling and AD diagnosis (n = 270), there was a significant association between presence of anti-HSV IgG antibodies and AD (OR 2.250, P = .019).

Conclusion
Among persons with a follow-up time of 6.6 years or more, HSV infection was significantly associated with AD.

Author Information -- Hugo Lövheimemail, Jonathan Gilthorpe, Anders Johansson, Sture Eriksson, Göran Hallmans, Fredrik Elgh

Source: Eureka Alert http://bit.ly/1t5wg5t

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