About HHV-6

For more information on HHV-6 and specific conditions:

HHV-6 & MS

HHV-6 & CFS

HHV-6 & Cancer

HHV-6 Overview

While it is generally known that this virus causes roseola and occasional seizures and encephalitis in infants, most physicians are not aware of other disease associations or the potential of HHV-6 to predispose patients to other disease states or influence the course of other diseases such as AIDS or MS causing them
to progress more rapidly due to selective immunosuppression. HHV-6 viral infection alters certain cytokines that make it more difficult for the body to fend off cancer, intracellular pathogens, viruses and mycobacteria. New research indicates that HHV-6 selectively blocks dendritic cell maturation and IL-12 p70 production (Lusso 2005).

HHV-6, a beta herpesvirus in the same family as cytomegalovirus, was discovered in 1986 in AIDS patients with cancer and lymphoproliferative disorders. It infects close to 100% of children by the age of two, causing mild flu-like symptoms in some, but in some cases proceeds to serious rash, high fever, encephalitis and seizures. A surprisingly high percentage of pediatric emergency room visits are due to primary HHV-6 infections. In some areas as many as 13% of infants with acute HHV-6 infections develop seizures and other manifestations of encephalitis. The virus can persist in the CNS. In most cases, the virus goes into latency; however, in patients with impaired immune function, the virus persists in its active state at low levels for years.

There are two distinct variants of HHV-6. Variant A or HHV-6A, is the predominant strain found in MS, CFS and AIDS patients. HHV-6B is the strain that causes roseola, febrile illnesses and encephalitis in infants, and reactivates in transplant patients leading to progression of CMV disease or rejection of the organ. HHV-6 suppresses bone marrow and can cause rejection or engraftment “no-take” in transplant patients.