Reactivated herpes simplex infection increases the risk of Alzheimer's disease

Alzheimers Dement. 2015 Jun;11(6):593-9. doi: 10.1016/j.jalz.2014.04.522. Epub 2014 Jul 17.

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.

Keywords: Alzheimer's disease; Cohort study; Dementia; HSV; Herpes; Herpes simplex.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Alzheimer Disease / epidemiology*
  • Alzheimer Disease / virology*
  • Antibodies, Viral / blood
  • Enzyme-Linked Immunosorbent Assay
  • Female
  • Follow-Up Studies
  • Herpes Simplex / epidemiology*
  • Herpes Simplex / virology*
  • Herpesvirus 1, Human / immunology
  • Herpesvirus 1, Human / physiology
  • Humans
  • Immunoglobulin G / blood
  • Immunoglobulin M / blood
  • Incidence
  • Kaplan-Meier Estimate
  • Longitudinal Studies
  • Male
  • Middle Aged
  • Prospective Studies
  • Risk
  • Virus Activation

Substances

  • Antibodies, Viral
  • Immunoglobulin G
  • Immunoglobulin M