• What Is XMRV?
• What is a Retrovirus?
• What's The Link Between XMRV and CFS/ME, Fibromyalgia and Other Neuro-Immune Diseases?
• What's The Link Between XMRV and Cancer or Other Diseases?
• Why Was XMRV Looked For In Neuro-Immune Diseases?
• What's The Prevalence of XMRV Infection In The General Population?
• How Is XMRV Transmitted?
• I'm Pregnant/Thinking About Getting Pregnant And Have CFS/ME, Should I Be Concerned?
• What Does It Mean If I'm Infected With XMRV?
• Can You Catch CFS/ME?
• Where Can I Get Tested For XMRV?
• What Can My Doctor Do For Me If I Test Positive To The XMRV Virus?
• How is The National Cancer Institute (NCI) Addressing Concerns About XMRV?
• Is XMRV Airborne?
• How Do I Volunteer For Clinical Trials or Other Research?
• Who Discovered XMRV?
• How Many Retroviruses Are There?
• I've Been Diagnosed With CFS/ME and Tested Positive For XMRV, Why Do I Look Normal?
• Now That XMRV Has Been Found in Men With Prostate Cancer and People With CFS/ME. What Does This Say About CFS/ME?
• Does This Information Prove Once and For All That CFS/ME Is Not a Psychological or Psychosomatic Illness?

Researchers at the Whittemore Peterson Institute in collaboration with the National Cancer Institute and the Cleveland Clinic, have recently discovered the presence of a retrovirus in blood samples from patients diagnosed with chronic CFS/ME. The human retrovirus, identified as XMRV, has now been found to be in over 95 percent of the patients' blood samples in this study group.

XMRV is a human retrovirus and is similar to HIV and HTLV-1. It was first identified by Dr. Robert Silverman, in prostate cancer tissue of men with a specific genetic defect in their antiviral defense pathway. Prior to the Whittemore Peterson Institute study, XMRV had not been isolated from a human diseased population or been shown to be infectious and transmissible.

A retrovirus is a type of virus that has RNA instead of DNA as its genetic material. RNA has several roles, but it primarily is the molecule that translates and transfers material from DNA. Inside the host cell, retroviral RNA is reverse transcribed to produce viral DNA that inserts into the host's chromosome, allowing many copies of the virus to be made. When retroviruses infect germ cells (sperm or egg), endogenous viruses, can develop. The integrated viral DNA, or provirus, is passed from parent to offspring. There is no evidence suggesting that XMRV can do this in humans.

Retroviruses are found in a wide range of mammals, and may contribute to the development of cancers, such as leukemia or lymphoma, and neurological diseases. The first of two human retroviruses identified, HTLV-1 has been found to cause adult T cell leukemia and HTLV-II is not associated with any disease. Human immunodeficiency virus (HIV), which causes AIDS, is a different type of retrovirus.

Our initial research showed that 67% of the CFS/ME patient samples tested positive for XMRV. Further work has found that 95% tested positive. Work continues to understand how this virus works within neuro-immune diseases, but this discovery proves a significant correlation between this serious retrovirus and these diseases. Our work suggests, but does not prove, that XMRV may be the underlying cause of CFS/ME. Much additional work needs to be done to understand how XMRV causes disease and what types of diseases it is linked to it.

A few fibromyalgia samples were tested and yes, they were positive. However the sampling was very small, and testing will have to continue on a much larger scale to begin to draw significant conclusions. In addition, many patients with CFS/ME have been given the diagnosis of fibromyalgia when in fact they have CFS/ME and fibromyalgia.

Whether XMRV plays a role in cancer and other diseases remains unclear. Research shows a possible association, but currently, there is no evidence that the virus causes a disease.

The virus was first discovered in tumors from men with prostate cancer and was mostly found in combination with a specific genetic defect in a gene called RNASEL, which, when unmutated, helps defend the body against viruses. Recent research has suggested that chronic viral infection with XMRV might be associated in some way with prostate cancer.

A 2009 study of more than 300 prostate tissue samples collected from American men found that XMRV was present in 27 percent of the tumor samples and six percent of the noncancerous prostate samples in men who had not been diagnosed with prostate cancer. The virus was more commonly found in men with aggressive tumors. But in this study, XMRV infection was not associated with the RNASEL defect, which may indicate that all individuals may be at risk. In contrast, a research group in Germany found no association between XMRV and prostate tumors. They analyzed 589 prostate tumor samples for the presence of the virus and tested blood samples from 146 of the prostate cancer patients for antibodies to the virus. Another German study and an Irish study found no evidence of a link between XMRV and prostate cancer. These differences in findings highlight the need for more research on this virus. The variation in results could be because of methodological differences or the studies were testing for different strains of XMRV. Another reason is that the virus may be more prevalent in certain geographical regions.

The virus has also been identified in patients with chronic fatigue syndrome. A study looking at clusters of cases in Nevada, Florida, and South Carolina found that 67 percent of 101 chronic fatigue syndrome patients were infected with XMRV, but less than four percent of 218 healthy people were infected. The virus was detected in white blood cells while viral particles were detected in plasma (the non-cellular portion of the blood).

Taken together, these findings do not indicate that XMRV causes cancer or chronic fatigue syndrome. If the virus is found to be the causative agent for any human disease, these findings could lead to better ways to screen for the disease, inform treatment strategies, and may eventually lead to strategies to prevent the occurrence of the disease, but much research will need to be done to establish causation before any of these tests or strategies would be undertaken.

Patients who have been diagnosed with CFS/ME have been shown to have a unique immune deficiency in a part of their antiviral system called the RNase L pathway. This pathway was also deficient in men whose cancer samples were first used in the discovery of XMRV. In this study, however, Whittemore Peterson Institute researchers have found XMRV in patients without an RNase L pathway deficiency. It is not known if XMRV causes this deficiency or if patients with this deficiency are more susceptible to the virus' effects or both.

The number of healthy people infected with XMRV, and what the distribution of infection is within the U.S. and worldwide, is unknown. The virus has been detected in about four percent of individuals from the same geographical region as infected patients with chronic fatigue syndrome. An analysis of more than 300 prostate tissue samples found that the virus was present in six percent of noncancerous prostates. These studies suggest that XMRV infection could be widespread, but there is no evidence for a new, increasing, or spreading XMRV infection. The NCI is developing molecular tools to determine the incidence of XMRV in the general population and is involved in coordinating a global effort to study the prevalence and distribution of XMRV.

The route(s) by which XMRV is transmitted from person to person are unknown. Some studies suggest that the virus may be transmitted though semen or saliva, but at this point, there is no direct evidence to support this suggestion. Given that the virus has been detected in white blood cells, blood-borne transmission is a possibility. More research is needed before guidelines can be established, but it might be prudent for potentially infected individuals to refrain from donating blood. It also is important to note that retroviruses, like XMRV, are not airborne viruses.

As a CFS/ME patient who is either pregnant or thinking about getting pregnant, you should speak with your physician regarding XMRV and safety measures you can use to minimize possible transmission of this virus to your child.

The research continues to fully understand the connection between CFS/ME and XMRV, as well as what it means to have the virus. We do not know all of the health ramifications of XMRV or CFS/ME, but we do know that some people with CFS/ME, have on average a lower life expectancy than someone without this chronic disease. In other studies XMRV has been detected in very aggressive cancerous prostate tumors. One may have XMRV and not have CFS/ME as evidenced by positive results of 3.7 percent of our control samples.

Causation of CFS/ME is likely to be a multi-factorial process which occurs in a susceptible person with common viral co-infections. CFS/ME is a complex, systemic neuro-immune disease that is estimated to affect over one million Americans and 17 million people worldwide. CFS/ME has traditionally been diagnosed by the exclusion of other similarly presenting conditions, such as MS and lupus, and by a series of symptoms; making the diagnosis an expensive and difficult process. Until now, a single viral link (while suspected by many) had not been made because so many common viruses have been found to be reactivated in persons with CFS/ME. This finding suggests a role for XMRV in the pathogenesis of CFS/ME and creates a better understanding of the disease. Our work suggests but does not prove that XMRV may be the underlying cause of CFS/ME. Much additional work needs to be done to understand how XMRV causes disease and what types of diseases it is linked to it.

The Whittemore Peterson Institute (WPI) is now allowing Viral Immune Pathology Diagnostics (VIP Dx) to temporarily offer the tests researchers used in the study linking XMRV to chronic fatigue syndrome (CFS/ME). Viral Immune Pathology Diagnostics (VIP Dx), in Reno, NV, which is also where the WPI is located. The institute says net proceeds from the test will be dedicated to further research.

For more information about the test kit, go to the VIP Dx website. At this time, this is the only lab test associated with the WPI research, although many companies are advertising XMRV tests online.

Research is still ongoing to determine the best treatments for those who are positive for XMRV. It is possible that antiviral therapies developed for other retroviruses may be useful against another RNA virus like XMRV. However, these are generally toxic therapies with considerable side effects making it imperative that one be very careful before beginning any new therapies. Obviously, only begin any therapies approved by your physician.

The NCI is working to develop diagnostic tools so that the prevalence of XMRV in the general public can be determined and its' association with disease can be examined. The origin and mode of XMRV transmission in human populations are key public health issues that NCI scientists are addressing.

Following a recent series of NCI-sponsored meetings, priorities were established to address research issues. The NCI is mobilizing its resources in cancer biology, diagnostic assay development, drug development, epidemiology (population studies), immunology, and retrovirology to address these issues as rapidly as possible, including:

• Developing suitable, well-validated tests to detect XMRV infection and using these to search for evidence of infection in forward-looking as well as historical population studies to understand the prevalence, distribution, relationship to disease (CFS, prostate cancer, and potentially other cancers), and mode of transmission of XMRV.


• Developing suitable models for infection and disease.


• Performing patient-based studies to probe the causality and mechanism of disease induction by the virus.

Studies to address these issues are well under way in the NCI and in many extramural laboratories.

No, retroviruses are not traditionally airborne viruses. However, since XMRV is a blood borne retrovirus, it may be possible to transmit through sexual contact, sharing needles, blood transfusions, and breastfeeding. Sharing household items like toothbrushes, razors, or items that come into contact with blood is not recommended as a precautionary measure.

If you are interested in possibly being selected to participate in ongoing or future Whittemore Peterson Institute (WPI) research studies visit their website and fill out the their website. While every study has specific requirements and not all who volunteer will be accepted, your willingness to participate is both crucial and deeply appreciated.

XMRV was originally discovered in prostate cancer tumors by Dr. Robert Silverman. Scientists from the Whittemore Peterson Institute, Cleveland Clinic and the National Cancer Institute were the first to discover XMRV in the blood of Chronic Fatigue Syndrome/Myalgic Encephalomyelitis (CFS/ME) patients.

Currently there are only three known infectious human retroviruses; HIV, HTLV-1 and 2 and now XMRV. HIV causes AIDS and HTLV-1 and 2 causes T-cell leukemia and T-cell lymphoma. XMRV is the most recent retrovirus discovered to infect humans and has been linked to neurological disease and prostate cancer.

Like other retroviruses known to infect humans, these illnesses appear to be invisible to the untrained eye. A physician, however, can see the signs of illness, and still must carefully examine the patient to know for certain who is ill and with what disease. Many diseases fall into this category. Unless one develops a disease that creates physical lesions that people can see e.g. psoriasis, the mask of lupus or the crippling bone changes of arthritis, most people can not see how debilitating the illness actually is. In addition, each person responds differently to treatment and therefore can maintain a higher quality of health and appearance of health. In the case of HIV, many people are infected but do not appear to be ill.

Contrary to popular opinion, CFS/ME is not a woman's disease. In fact the epidemiological study done by Dr. Lenny Jason has shown that this disease occurs in men and women and is also prevalent in children. Instances of outbreaks in which entire families and groups of friends became ill near the same time, have been reported across the US, the UK and other countries.

Absolutely! Actually, there are thousands of research articles showing the very real biological problems that CFS/ME patient's experience such as low NK cell count and function, MRI and SPEC scan changes, and repeated chronic infections, to mention just a few. Only the most stubborn and misinformed individuals refuse to believe that this disease is real and serious. The process of placing poorly understood illnesses into a psychological category is very similar to what happened in the early days of MS and epilepsy before the advent of technologies which proved the illnesses were "real." Unfortunately, many in the scientific and medical fields have not learned from their past mistakes.

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