From The Times
December 6, 2008
Virus clue to cause of Alzheimer’s
Mark Henderson, Science Editor Times December 6th
Alzheimer’s disease is a debilitating destructive condition wherein the mind evaporates over a period of time. This has terrible consequences for the person and thir family. This also has nutritional consequences.
Compelling new evidence found by British scientists has implicated the cold sore virus, known as herpes simplex virus 1 (HSV1), in up to 60 per cent of Alzheimer’s cases. The team is lead by Professor Ruth Itzhaki, in Manchester University.
Cheap antiviral drugs that can control HSV1 infections, such as acyclovir or Zovirax, have been available for many years, and are sufficiently safe to be sold over the counter. Antiviral drugs such as acyclovir, sold under the brand name Zovirax, can control HSV1 during the active phase of its life cycle, during which it causes cold sores. If HSV1’s role is confirmed, and antivirals are proved effective against the virus in the brain, the research would raise the prospect of stopping the progressive damage caused by Alzheimer’s in its tracks. This would allow hundreds of elderly people to avoid progressive cognitive decline that is highly distressing to them and their families, and to lead independent lives.
“Although HSV1 is very common, infecting most adults and causing cold sores in about 20 to 40 per cent of them, the research does not suggest that everybody or even most people who suffer from cold sores will get Alzheimer’s. If the link is proved, it would be one of several factors, some of which are genetic, and early indications are that HSV1 might contribute to up to 60 per cent of cases.
HSV1’s potential role in Alzheimer’s is in the formation of plaques of beta amyloid protein that build up in the brain cells, which are thought to be its main cause.
The new research, published in the Journal of Pathology, goes significantly farther, as it has found firm evidence of HSV1 infection in protein plaques in the brain cells of Alzheimer’s patients.
The scientists used the genetic analysis technique called the in-situ polymerase chain reaction to detect HSV1 DNA in these protein plaques. This shows that the virus is associated with such build-ups, and suggests that it might be a significant cause.
HSV1, a cousin of the HSV2 virus that causes genital herpes, hides in the peripheral nervous system in a latent form, and periodically becomes active to cause cold sores in 20 to 40 per cent of carriers. The Manchester scientists believe that HSV1 may enter the brain and become active as people’s ageing immune systems lose the ability to keep it contained.
Sources: Alzheimer’s Society, Times Archive
- Martin Eastwood