[High prevalence without reactivation of herpes virus 6 in subjects with chronic fatigue syndrome]

An Med Interna. 1997 Sep;14(9):441-4.
[Article in Spanish]


Introduction: Chronic fatigue syndrome (CFS) is a disorder of unknown etiology. Some viruses have been associated with CFS etiology, specially herpesviruses, enteroviruses and retroviruses. Some studies suggest an association between human herpesvirus-6 (HHV-6) and CFS. In order to know if there is an active HHV-6 infection in CFS patients we studied the immunologic and virologic status of HHV-6.

Materials and methods: Twenty patients with CFS were studied. IgG and IgM anti HHV-6 were determined by indirect immunofluorescence assay. DNA from serum and peripheral blood mononuclear cells (PBMC) were studied by dot- and Southern-blotting and nested-PCR to detect HHV-6 DNA. HHV-6 RNA from PBMC were amplified by RT(retrotranscription)-PCR.

Results: Ten patients (50%) had IgG anti-HHV-6 in serum but none had IgM anti-HHV-6. Dot-blotting of DNA from 200 microliters of serum and Southern-blotting of 10 micrograms of PBMC DNA were negative. Nested-PCR from sera were negative. Nested-PCR with 1 microgram PBMC DNA were positive in 8 out 20 (40%) and with 5 micrograms PBMC DNA were positive in 16 out of 20 (80%). No viral RNA were detected in PBMC.

Conclusions: There is a high proportion of CFS patients infected with HHV-6 but with low viral load. Results do not support HHV-6 reactivation in CFS patients.

Publication types

  • English Abstract

MeSH terms

  • Adult
  • Fatigue Syndrome, Chronic / blood
  • Fatigue Syndrome, Chronic / virology*
  • Female
  • Herpesvirus 6, Human / immunology
  • Herpesvirus 6, Human / isolation & purification*
  • Herpesvirus 6, Human / physiology
  • Humans
  • Immunoglobulin G / blood
  • Immunoglobulin M / blood
  • Male
  • Middle Aged
  • Prevalence


  • Immunoglobulin G
  • Immunoglobulin M