NEW YORK (Reuters Health) - Brain tissue of patients with the familial type of Alzheimer’s disease (AD) has a high concentration of reactivated herpes simplex virus type 1 (HSV-1), Japanese investigators report.
HSV-1 is believed to be an environmental risk factor for sporadic AD, Dr. Isamu Mori, at Aichi Medical University School of Medicine, and colleagues explain in their paper, published in the Journal of Medical Virology for August, but its association with familial AD is not known.
They therefore examined postmortem brain tissue sections of five middle-aged patients -- three with familial AD, two with sporadic AD -- and six control subjects.
Nested polymerase chain reaction testing revealed HSV-1-specific DNA in the frontal and temporal lobes of all five patients with AD, but only in the frontal lobe of one control subject, a significant difference (p < 0.05).
In situ hybridization of the tyramide signal amplification system detected HSV DNA in the cytoplasm of cortical neurons, frequently in contact with amyloid beta-42 deposition. According to the authors, these results are highly suggestive of HSV-1 reactivation, which possibly leads to sustained neurodegeneration.
Therefore, “preventive and therapeutic measures against HSV-1 should be taken not only with sporadic but also for familial Alzheimer’s disease patients,” they write, “since repeated reactivation of HSV-1 in neurons likely promotes neurodegeneration in the Alzheimer’s disease brains.”
Source: J Med Virol 2004;73:605-611. [ Google search on this article ]
MeSH Headings:Amyloid: Polymerase Chain Reaction: Amyloid beta-ProteinCopyright © 2002 Reuters Limited. All rights reserved. Republication or redistribution of Reuters content, including by framing or similar means, is expressly prohibited without the prior written consent of Reuters. Reuters shall not be liable for any errors or delays in the content, or for any actions taken in reliance thereon. Reuters and the Reuters sphere logo are registered trademarks and trademarks of the Reuters group of companies around the world.
