Herpesviruses

From MEpedia, a crowd-sourced encyclopedia of ME and CFS science and history

Herpesviruses are a family of DNA viruses with extremely high prevalence rates. Once a human host is infected, the infection is life-long. While generally, immunocompetent hosts are able to keep the virus in a latent state and remain asymptomatic, several of these viruses can cause symptoms if they reactivate. They can also increase the risk of autoimmune disease and cancer.[1][2]

Types[edit | edit source]

Viruses in this family include HSV-1 and HSV-2, Epstein-Barr virus (HHV4), which causes mononucleosis, Varicella zoster virus, which causes chickenpox and shingles. More than 90% of adults have been infected with at least one of these viruses.

Other herpesviruses include human cytomegalovirus, HHV-6, HHV-7, and Kaposi's sarcoma-associated herpesvirus.

Latency[edit | edit source]

They share in common that after the initial infection, these viruses usually remain latent for life.[3]

Reactivation[edit | edit source]

Reactivation of these viruses have been associated with a number of diseases.[citation needed] HSV-1 has been implicated in Alzheimer's.[4]

Several of these viruses have transactivating potential, that is, they can cause the increased rate of gene expression of other viruses.[3]

Chronic fatigue syndrome[edit | edit source]

It is unclear whether herpesviruses associated with Chronic fatigue syndrome play an etiological role or are "bystanders" – opportunistic reactivations under a state of immune dysregulation. In the 1984 Incline village outbreak, Gary Holmes found that patients with what his team hypothesized was chronic Epstein-Barr had elevated antibody titers to Epstein-Barr virus, cytomegalovirus, herpes simplex and measles viruses than age-matched controls.[5] However, the study cohort was defined as patients who had experienced excessive fatigue between January 1 and September 15. 

A prospective study of 250 primary care patients revealed a higher prevalence of chronic fatigue syndrome after infectious mononucleosis (glandular fever) when compared to an ordinary upper respiratory tract infection.[6] Anti-early antigen titers to Epstein-Barr virus were elevated in CFS patients and associated with worse symptoms.[7]

Studies related to Herpesviruses and ME/CFS[edit | edit source]

"In this review, we provide evidence from animal and human studies of the Epstein-Barr virus as a prototype, supporting the notion that herpesviruses dUTPases are a family of proteins with unique immunoregulatory functions that can alter the inflammatory microenvironment and thus exacerbate the immune pathology of herpesvirus-related diseases including myalgic encephalomyelitis/chronic fatigue syndrome, autoimmune diseases, and cancer...[we] approached the possibility that two or more herpesviruses may act synergistically and that virus-encoded proteins, rather than the viruses themselves, may act as drivers of or contribute to the pathophysiological alterations observed in a subset of patients with ME/CFS."[8]

See also[edit | edit source]

Learn more[edit | edit source]

References[edit | edit source]

  1. White, Douglas W.; Beard, R. Suzanne; Barton, Erik S. (January 2012). "Immune Modulation During Latent Herpesvirus Infection". Immunological reviews. 245 (1): 189–208. doi:10.1111/j.1600-065X.2011.01074.x. ISSN 0105-2896. PMC 3243940. PMID 22168421.
  2. "Viruses that can lead to cancer". www.cancer.org. Retrieved August 20, 2020.
  3. 3.0 3.1 De Bolle, Leen; Naesens, Lieve (January 2005), "Update on Human Herpesvirus 6 Biology, Clinical Features, and Therapy", Clin Microbiol Rev, 8 (1): 217–245, doi:10.1128/CMR.18.1.217-245.200
  4. Experts Say There’s a Herpes-Alzheimer’s Link, Time, March 10, 2016
  5. Homes, Gary P (May 1, 1987). "A Cluster of Patients With a Chronic Mononucleosis-like Syndrome Is Epstein-Barr Virus the Cause?". Journal of the American Medical Association. 257: 2297–2302.
  6. White, P. D.; Thomas, J. M.; Amess, J.; Crawford, D. H.; Grover, S. A.; Kangro, H. O.; Clare, A. W. (December 1998). "Incidence, risk and prognosis of acute and chronic fatigue syndromes and psychiatric disorders after glandular fever". The British Journal of Psychiatry: The Journal of Mental Science. 173: 475–481. ISSN 0007-1250. PMID 9926075.
  7. Schmaling, K. B.; Jones, J. F. (January 1996). "MMPI profiles of patients with chronic fatigue syndrome". Journal of Psychosomatic Research. 40 (1): 67–74. ISSN 0022-3999. PMID 8730646.
  8. Williams, Marshall V.; Cox, Brandon; Ariza, Maria Eugenia (2017), "Herpesviruses dUTPases: A New Family of Pathogen-Associated Molecular Pattern (PAMP) Proteins with Implications for Human Disease", Pathogens, 6 (1): 2, doi:10.3390/pathogens6010002