John Cunningham virus

John Cunningham virus, but universally called the JC virus, is a ubiquitous double-stranded DNA virus of the polyomaviridae family 1. In immunocompromised individuals, reactivation can lead to a variety of disease of the central nervous system, the most common of which is progressive multifocal leukoencephalopathy (PML).

It has been reported that ~70% of adults have been exposed to this virus; however, no significant clinical syndrome has been associated with this acquisition in the majority of immunocompetent hosts 1

Numerous causes of immunosuppression have been implicated in reactivation of the virus, including HIV/AIDS, malignancy (e.g. lymphoma) and immunomodulators (e.g. natalizumab for multiple sclerosis). 

Infection with JC virus, usually asymptomatic, results in latent infection in various organs and tissues of the body. When patients are immunocompromised the virus can reactivate and migrate to the central nervous system, with a predilection of glial cells, thus resulting in the classical leukoencephalopathy of progressive multifocal leukoencephalopathy (PML) 6.

Occasionally, mutations of the virus result in other cell types being targetted with resultant distinct clinical manifestations including 4-6

The virus was first described by Åström et al. in 1958 2, and was first isolated in 1971 by Padgett et al. The latter group assigned the name of the patient to the virus 3.

Infections of the central nervous system

Article information

rID: 37530
Section: Pathology
Synonyms or Alternate Spellings:
  • JC virus

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