Different characteristics of human herpesvirus 6 encephalitis between primary infection and viral reactivation

J Clin Virol. 2011 May;51(1):12-9. doi: 10.1016/j.jcv.2011.02.002. Epub 2011 Mar 3.

Abstract

Background: Pathogenesis of human herpesvirus 6 (HHV-6) encephalitis, in particular difference between HHV-6 encephalitis at the time of primary infection and reactivation remains unclear.

Objectives: To elucidate the mechanism of HHV-6 encephalitis at the time of primary infection and reactivation.

Study design: Twenty-two HHV-6 encephalitis patients at the time of primary infection, 6 febrile convulsion (FC) patients caused by HHV-6 infection, and 14 FC patients without HHV-6 infection (non HHV-6 FC) were enrolled. Additionally, 7 stem cell transplant recipients with HHV-6 encephalitis and eight adult controls were also enrolled in this study. Cerebrospinal fluid (CSF) HHV-6 DNA copy numbers and biomarkers levels were compared.

Results: Low copy number of CSF HHV-6 DNA was detected in 7 of the 22 patients with HHV-6 encephalitis in primary infection, whereas all seven CSF samples collected from post-transplant HHV-6 encephalitis patients contained high viral DNA copy numbers (P<0.001). CSF concentrations of IL-6 (P=0.032), IL-8 (P=0.014), MMP-9 (P=0.004), and TIMP-1 (P=0.002) were significantly higher in patients with HHV-6 encephalitis in primary infection than non-HHV-6 FC. CSF IL-6 (P=0.008), IL-8 (P=0.015), and IL-10 (P=0.019) concentrations were significantly higher in patients with post-transplant HHV-6 encephalitis than adult controls.

Conclusion: The present study suggests that the characteristics of HHV-6 encephalitis are different between HHV-6 encephalitis at the time of primary infection and reactivation in transplant recipients.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Biomarkers / cerebrospinal fluid
  • Case-Control Studies
  • Child, Preschool
  • DNA, Viral / cerebrospinal fluid
  • Encephalitis, Viral / cerebrospinal fluid
  • Encephalitis, Viral / virology*
  • Female
  • Herpesvirus 6, Human / genetics
  • Herpesvirus 6, Human / pathogenicity
  • Herpesvirus 6, Human / physiology*
  • Humans
  • Infant
  • Interleukins / cerebrospinal fluid
  • Male
  • Matrix Metalloproteinase 9 / cerebrospinal fluid
  • Middle Aged
  • Polymerase Chain Reaction
  • Recurrence
  • Roseolovirus Infections / cerebrospinal fluid
  • Roseolovirus Infections / virology*
  • Seizures, Febrile / virology
  • Tissue Inhibitor of Metalloproteinase-1 / cerebrospinal fluid
  • Transplantation / statistics & numerical data
  • Virus Activation*

Substances

  • Biomarkers
  • DNA, Viral
  • Interleukins
  • Tissue Inhibitor of Metalloproteinase-1
  • Matrix Metalloproteinase 9