CFS/ME and Retroviruses

New XMRV Study Not The First To Find a Retroviral Link

Oct 10, 2009 Maija Haavisto

Chronic fatigue syndrome/myalgic encephalomyelitis (CFS/ME) is a disabling neurological illness. New study suggests it might be caused by the retrovirus XMRV.

A new study published in the prestigious journal Science found the retrovirus XMRV (xenotropic murine leukemia virus-related virus) in 67% of patients with chronic fatigue syndrome/myalgic encephalomyelitis (CFS/ME). Only 3.7% of the studied healthy controls harbored this infection. Later, the researchers reported up to 95% of patients test positive with antibody testing.

XMRV belongs to the group of gammaretroviruses and has previously been associated with prostate cancer. Little is known about most types of human retroviruses, aside from the best known one: HIV.

This is not the first time CFS/ME has been associated with a chronic viral infection - it used to be called "post-viral fatigue syndrome," after all. In studies, CFS/ME has been connected with a variety of different viruses, including:

• herpes viruses (especially Epstein-Barr virus, cytomegalovirus and HHV-6)
• enteroviruses (polioviruses, Coxsackie viruses, echoviruses)
• parainfluenza virus 5 (PIV-5)
• parvovirus B19
• various retroviruses

History of CFS/ME and Retroviruses

The study group of Elaine DeFreitas reported a link between CFS/ME and retroviruses back in 1991. This virus was most closely related to HTLV-2 (human T-lymphotropic virus 2), which belongs to a different group of retroviruses, deltaretroviruses. None of the healthy controls in the study showed evidence of this virus.

Immunovirologist Michael Holmes described retroviral activity in cells of CFS/ME patients as early as 1986. However, he did not elucidate on the type of the retrovirus. Another researcher, John Martin, reported finding a spumavirus type retrovirus in CFS/ME in the early 1990s.

Conclusions

The XMRV finding does not prove that CFS/ME is caused or triggered by this retrovirus. More research will be needed to confirm the role of XMRV in CFS/ME, and the full effects of this virus in general.

The other viruses could still play a part. The authors of the XMRV study believe the retrovirus may reactivate other viruses, such as herpesviruses (the opposite is also possible). There could be many different viruses behind CFS/ME. And it could be that XMRV is an incidental finding secondary to the immune dysfunction in CFS/ME.

The XMRV test is currently only in research use, but if the connection with CFS/ME (and/or other illnesses) is confirmed, it is likely to become more widely available. Many other diagnostic tests for CFS/ME are also being studied.

XMRV is thought to be transmitted in the same way as HIV: not through air or by touch, but through bodily fluids. Could this make CFS/ME a contagious illness? It is already widely considered infectious and numerous epidemics have been reported since the 1930s, but genes and other predisposing factors also appear to play a role in getting sick.

XMRV and Cancer

If XMRV causes CFS/ME, does CFS/ME increase the risk of prostate cancer? It is too early to determine. While CFS/ME appears to increase the risk of many cancers, including leukemia, lymphoma, cervical cancer and some brain tumors, no increased risk of prostate cancer has been reported.

The same virus may cause a different illness in different groups of people. For example, Coxsackie B4 virus has been connected to both CFS/ME epidemics and juvenile (type I) diabetes, but an association between type I diabetes and CFS/ME is yet to be reported.

Treatment of XMRV

Antiretroviral drugs are used in HIV infection and could be used to treat XMRV, but they have significant, often permanent side effects. Antiherpesvirals and other antiviral medications have been successfully used in CFS/ME treatment - but they are much less toxic than antiretrovirals. There are dozens of effective treatments for CFS/ME, so if antiretrovirals are not curative (as is the situation with HIV), it is hard to support their use.

Low dose naltrexone (LDN) has been used in AIDS treatment since the 1980s and is currently in a clinical HIV/AIDS trial in Africa. LDN appears to work at least as well as antiretroviral therapy, with negligible side effects. It has also been successfully used in the treatment of CFS/ME.

XMRV leads to immune dysfunction by damaging an antiviral pathway called RNase L. Ampligen, an immunostimulant drug currently waiting for FDA approval for treatment of CFS/ME works by treating this deficiency.

References

Lombardi VC, Ruscetti FW, Das Gupta J. Detection of an Infectious Retrovirus, XMRV, in Blood Cells of Patients with Chronic Fatigue Syndrome. Science. Published online October 8 2009.

Haavisto Maija. Reviving the Broken Marionette: Treatments for CFS/ME and Fibromyalgia. 2008.

DeFreitas E, Hilliard B, Cheney PR, et al. Retroviral sequences related to human T-lymphotropic virus type II in patients with chronic fatigue immune dysfunction syndrome. Proc Natl Acad Sci U S A. 1991 Apr 1;88(7):2922-6.

Hyde B (ed). The Clinical and Scientific Basis of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome. 1992. pp. 89-90, 190, 193-194, 319-339, 568.

Bihari B, Drury F, Ragone V, et al. Low dose naltrexone in the treatment of AIDS: long term follow-up results. V International Conference on AIDS. Poster M. C.P. 62. Montreal, June 1989.

The copyright of the article CFS/ME and Retroviruses in General Medicine is owned by Maija Haavisto. Permission to republish CFS/ME and Retroviruses in print or online must be granted by the author in writing.

HIV - the most well known retrovirus

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Comments

Oct 10, 2009 9:25 PM

Guest :

i know it is caused by a virus. I've known for years bc I knew exactly when I got sick and by whom. And all I did was kiss the boy - for probably an hour -nothing else. He was told he had mono. He told me he wasnt sick that it goes away in a month according to his doctor. Next thing I got slight sore throats for weeks -finally got strep throat on spring break and was so sick I brought to hospital. Been sick since i was 16. I am 34 now and life has sucked! No doc would listen to me, but i knew and there are others in my school in similar situation.

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