[Alzheimer's disease and HSV-1 infection]

Alzheimer's disease is a complex neurodegenerative disorder. Several risk factors have been reported and compiled from genetic and epidemiological studies. Many theories on the cause of Alzheimer's disease have been proposed over the past. Amyloid hypothesis is still the most important one and guides a lot of scientific research on AD. But there is general consent that amyloid deposits are the products of degenerating neurons, not a cause of degeneration. Recently, epidemiological data for the correlation between HSV-1 infection and AD have been collected. It was revealed that HSV-1 is present in a latent form in the brains of a high proportion of elderly people and is a risk factor for AD in carriers of APOEepsilon4. On the other hand, there is negative evidence for HSV-1 as a risk factor of APOEepsilon4 positive AD cases. Finally, some investigations raise a possibility that viruses other than HSV-1 may influence Alzheimer's disease. In the present paper the possible role of HSV-1 infection in pathology of AD is discussed.