XMRV: does this virus hold the key to myalgic encephalomyelitis/CFS?

Abstract:

In October 2009 a team of researchers from the Whittemore Peterson Institute, in association with the National Cancer Institute and the Cleveland Clinic in the USA, made a discovery that could potentially open the door to useful treatments for myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS). The researchers, led by Judy Mikovits, discovered a significant correlation between ME/CFS and an infectious retrovirus called xenotropic murine leukaemia virus-related virus (XMRV). XMRV is classified as a gammaretrovirus, belonging to the same broad family as HIV, but more closely related to a group of viruses that cause cancers such as leukaemia. XMRV is the first member of the gammaretrovirus genus of retroviruses to be found in humans; the research to fully understand the connection between ME/CFS and XMRV, as well as what it means to have the virus, is ongoing. The disastrous impact of AIDS on human health has significantly raised the profile of retroviruses as human pathogens, and XMRV has potentially serious health implications not only for patients, but also for those caring for people with ME/CFS.

 

Source: Crowhurst G. XMRV: does this virus hold the key to myalgic encephalomyelitis/CFS? Br J Nurs. 2010 Jul 22-Aug 11;19(14):919-22. https://www.ncbi.nlm.nih.gov/pubmed/20647985

 

Absence of evidence of xenotropic murine leukemia virus-related virus infection in persons with chronic fatigue syndrome and healthy controls in the United States

Abstract:

BACKGROUND: XMRV, a xenotropic murine leukemia virus (MuLV)-related virus, was recently identified by PCR testing in 67% of persons with chronic fatigue syndrome (CFS) and in 3.7% of healthy persons from the United States. To investigate the association of XMRV with CFS we tested blood specimens from 51 persons with CFS and 56 healthy persons from the US for evidence of XMRV infection by using serologic and molecular assays. Blinded PCR and serologic testing were performed at the US Centers for Disease Control and Prevention (CDC) and at two additional laboratories.

RESULTS: Archived blood specimens were tested from persons with CFS defined by the 1994 international research case definition and matched healthy controls from Wichita, Kansas and metropolitan, urban, and rural Georgia populations. Serologic testing at CDC utilized a Western blot (WB) assay that showed excellent sensitivity to MuLV and XMRV polyclonal or monoclonal antibodies, and no reactivity on sera from 121 US blood donors or 26 HTLV-and HIV-infected sera. Plasma from 51 CFS cases and plasma from 53 controls were all WB negative. Additional blinded screening of the 51 cases and 53 controls at the Robert Koch Institute using an ELISA employing recombinant Gag and Env XMRV proteins identified weak seroreactivity in one CFS case and a healthy control, which was not confirmed by immunofluorescence. PCR testing at CDC employed a gag and a pol nested PCR assay with a detection threshold of 10 copies in 1 ug of human DNA. DNA specimens from 50 CFS patients and 56 controls and 41 US blood donors were all PCR-negative. Blinded testing by a second nested gag PCR assay at the Blood Systems Research Institute was also negative for DNA specimens from the 50 CFS cases and 56 controls.

CONCLUSIONS: We did not find any evidence of infection with XMRV in our U.S. study population of CFS patients or healthy controls by using multiple molecular and serologic assays. These data do not support an association of XMRV with CFS.

 

Source: Switzer WM, Jia H, Hohn O, Zheng H, Tang S, Shankar A, Bannert N, Simmons G, Hendry RM, Falkenberg VR, Reeves WC, Heneine W. Absence of evidence of xenotropic murine leukemia virus-related virus infection in persons with chronic fatigue syndrome and healthy controls in the United States. Retrovirology. 2010 Jul 1;7:57. doi: 10.1186/1742-4690-7-57. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2908559/ (Full article)

 

Comment on “Detection of an infectious retrovirus, XMRV, in blood cells of patients with chronic fatigue syndrome

Abstract:

Lombardi et al. (Reports, 23 October 2009, p. 585) reported an association between the human gammaretrovirus XMRV and chronic fatigue syndrome. However, their results may be misleading because of various potential sources of bias and confounding. If real, the association may lack generalizability because of the specific characteristics of the cases studied and could be due to reverse causality.

Comment on: Detection of an infectious retrovirus, XMRV, in blood cells of patients with chronic fatigue syndrome. [Science. 2009]

You can read the rest of this comment here: http://science.sciencemag.org/content/328/5980/825.1.full

 

Source: Sudlow C, Macleod M, Al-Shahi Salman R, Stone J. Comment on “Detection of an infectious retrovirus, XMRV, in blood cells of patients with chronic fatigue syndrome”. Science. 2010 May 14;328(5980):825; author reply 825. doi: 10.1126/science.1183545. http://science.sciencemag.org/content/328/5980/825.1.full (Full article)

 

Comment on “Detection of an infectious retrovirus, XMRV, in blood cells of patients with chronic fatigue syndrome”

Abstract:

Lombardi et al. (Reports, 23 October 2009, p. 585) reported a significant association between the human retrovirus XMRV and chronic fatigue syndrome (CFS). However, the cases with CFS and the control subjects in their study are poorly described and unlikely to be representative. Independent replication is a critical first step before accepting the validity of this finding.

Comment on: Detection of an infectious retrovirus, XMRV, in blood cells of patients with chronic fatigue syndrome. [Science. 2009]

You can read the full comment here: http://science.sciencemag.org/content/328/5980/825.2.full

 

Source: Lloyd A, White P, Wessely S, Sharpe M, Buchwald D. Comment on “Detection of an infectious retrovirus, XMRV, in blood cells of patients with chronic fatigue syndrome”. Science. 2010 May 14;328(5980):825; author reply 825. doi: 10.1126/science.1183706. http://science.sciencemag.org/content/328/5980/825.2.full (Full article)

 

Comment on “Detection of an infectious retrovirus, XMRV, in blood cells of patients with chronic fatigue syndrome”

Abstract:

Lombardi et al. (Reports, 23 October 2009, p. 585) reported detection of the human gammaretrovirus XMRV in the blood cells of patients with chronic fatigue syndrome (CFS). However, the patient description provided was incomplete. The inclusion of patients from a “CFS outbreak” previously linked with a viral infection, without confirmation in sporadic CFS cases, casts doubt on the role of XMRV in the pathogenesis of CFS.

You can read the full comment herehttp://science.sciencemag.org/content/328/5980/825.3.full

Comment on: Detection of an infectious retrovirus, XMRV, in blood cells of patients with chronic fatigue syndrome. [Science. 2009]

 

Source: van der Meer JW, Netea MG, Galama JM, van Kuppeveld FJ. Comment on “Detection of an infectious retrovirus, XMRV, in blood cells of patients with chronic fatigue syndrome”. Science. 2010 May 14;328(5980):825; author reply 825. doi: 10.1126/science.1183906. http://science.sciencemag.org/content/328/5980/825.3.long (Full article)

 

Prevalence of xenotropic murine leukaemia virus-related virus in patients with chronic fatigue syndrome in the Netherlands: retrospective analysis of samples from an established cohort

Abstract:

OBJECTIVE: The presence of the retrovirus xenotropic murine leukaemia virus-related virus (XMRV) has been reported in peripheral blood mononuclear cells of patients with chronic fatigue syndrome. Considering the potentially great medical and social relevance of such a discovery, we investigated whether this finding could be confirmed in an independent European cohort of patients with chronic fatigue syndrome.

DESIGN: Analysis of a well defined cohort of patients and matched neighbourhood controls by polymerase chain reaction.

SETTING: Certified (ISO 15189) laboratory of clinical virology in a university hospital in the Netherlands. Population Between December 1991 and April 1992, peripheral blood mononuclear cells were isolated from 76 patients and 69 matched neighbourhood controls. In this study we tested cells from 32 patients and 43 controls from whom original cryopreserved phials were still available.

MAIN OUTCOME MEASURES: Detection of XMRV in peripheral blood mononuclear cells by real time polymerase chain reaction assay targeting the XMRV integrase gene and/or a nested polymerase chain reaction assay targeting the XMRV gag gene.

RESULTS: We detected no XMRV sequences in any of the patients or controls in either of the assays, in which relevant positive and negative isolation controls and polymerase chain reaction controls were included. Spiking experiments showed that we were able to detect at least 10 copies of XMRV sequences per 10(5) peripheral blood mononuclear cells by real time as well as by nested polymerase chain reaction, demonstrating high sensitivity of both assays.

CONCLUSIONS: This study failed to show the presence of XMRV in peripheral blood mononuclear cells of patients with chronic fatigue syndrome from a Dutch cohort. These data cast doubt on the claim that XMRV is associated with chronic fatigue syndrome in the majority of patients.

Comment in: Chronic fatigue syndrome and human retrovirus XMRV. [BMJ. 2010]

 

Source: van Kuppeveld FJ, de Jong AS, Lanke KH, Verhaegh GW, Melchers WJ, Swanink CM, Bleijenberg G, Netea MG, Galama JM, van der Meer JW. Prevalence of xenotropic murine leukaemia virus-related virus in patients with chronic fatigue syndrome in the Netherlands: retrospective analysis of samples from an established cohort. BMJ. 2010 Feb 25;340:c1018. doi: 10.1136/bmj.c1018. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2829122/ (Full article)

 

Of Mice and Men: On the Origin of XMRV

Abstract:

The novel human retrovirus xenotropic murine leukemia virus-related virus (XMRV) is arguably the most controversial virus of this moment. After its original discovery in prostate cancer tissue from North American patients, it was subsequently detected in individuals with chronic fatigue syndrome from the same continent. However, most other research groups, mainly from Europe, reported negative results.

The positive results could possibly be attributed to contamination with mouse products in a number of cases, as XMRV is nearly identical in nucleotide sequence to endogenous retroviruses in the mouse genome. But the detection of integrated XMRV proviruses in prostate cancer tissue proves it to be a genuine virus that replicates in human cells, leaving the question: how did XMRV enter the human population?

We will discuss two possible routes: either via direct virus transmission from mouse to human, as repeatedly seen for, e.g., Hantaviruses, or via the use of mouse-related products by humans, including vaccines. We hypothesize that mouse cells or human cell lines used for vaccine production could have been contaminated with a replicating variant of the XMRV precursors encoded by the mouse genome.

 

Source: van der Kuyl AC, Cornelissen M, Berkhout B. Of Mice and Men: On the Origin of XMRV. Front Microbiol. 2011 Jan 17;1:147. doi: 10.3389/fmicb.2010.00147. ECollection 2010. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3109487/ (Full article)

 

Detection of an infectious retrovirus, XMRV, in blood cells of patients with chronic fatigue syndrome

Abstract:

Chronic fatigue syndrome (CFS) is a debilitating disease of unknown etiology that is estimated to affect 17 million people worldwide. Studying peripheral blood mononuclear cells (PBMCs) from CFS patients, we identified DNA from a human gammaretrovirus, xenotropic murine leukemia virus-related virus (XMRV), in 68 of 101 patients (67%) as compared to 8 of 218 (3.7%) healthy controls. Cell culture experiments revealed that patient-derived XMRV is infectious and that both cell-associated and cell-free transmission of the virus are possible. Secondary viral infections were established in uninfected primary lymphocytes and indicator cell lines after their exposure to activated PBMCs, B cells, T cells, or plasma derived from CFS patients. These findings raise the possibility that XMRV may be a contributing factor in the pathogenesis of CFS.

Comment in:

Erratum in: Partial retraction. Detection of an infectious retrovirus, XMRV, in blood cells of patients with chronic fatigue syndrome. [Science. 2011]

Retraction in: Retraction. [Science. 2011]

 

Source: Lombardi VC, Ruscetti FW, Das Gupta J, Pfost MA, Hagen KS, Peterson DL, Ruscetti SK, Bagni RK, Petrow-Sadowski C, Gold B, Dean M, Silverman RH, Mikovits JA. Detection of an infectious retrovirus, XMRV, in blood cells of patients with chronic fatigue syndrome. Science. 2009 Oct 23;326(5952):585-9. doi: 10.1126/science.1179052. Epub 2009 Oct 8. http://science.sciencemag.org/content/326/5952/585.long (Full article)

 

Virology. A new virus for old diseases?

There is little consensus in the medical community on whether chronic fatigue syndrome is a distinct disease. As its name implies, the condition is characterized by debilitating fatigue persisting for many years, and it affects as much as 1% of the world’s population. Although chronic inflammation is often found in these patients, no infectious or toxic agent has been clearly implicated in this disease, which is diagnosed largely by excluding other conditions that cause similar symptoms (1). In this week’s Science Express, Lombardi et al. (2) describe the detection of xenotropic murine leukemia virus–related virus (XMRV) in about two-thirds of patients diagnosed with chronic fatigue syndrome. Both laboratory and epidemiological studies are now needed to determine whether this virus has a causative role, not only in this disease, but perhaps in others as well.

Chronic fatigue syndrome is not the first human disease to which XMRV has been linked. The virus first was described about 3 years ago in a few prostate cancer patients (3), and recently detected in nearly a quarter of all prostate cancer biopsies (4). It has been isolated from both prostate cancer and chronic fatigue syndrome patients, and is similar to a group of endogenous murine leukemia viruses (MLVs) found in the genomes of inbred and related wild mice. Although a half century of studies on MLVs and other gammaretroviruses have led to important discoveries on which much of our current understanding of cancer rests, there has been no clear evidence demonstrating human infection with gammaretroviruses, or associating these agents with any human disease.

You can read the rest of this article here: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2818280/

Comment on: Detection of an infectious retrovirus, XMRV, in blood cells of patients with chronic fatigue syndrome. [Science. 2009]

 

Source: Coffin JM, Stoye JP. Virology. A new virus for old diseases? Science. 2009 Oct 23;326(5952):530-1. doi: 10.1126/science.1181349. Epub 2009 Oct 8. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2818280/ (Full article)

 

Electron microscopic immunocytological profiles in chronic fatigue syndrome

Abstract:

Structures consistent in size, shape and character with various stages of a Lentivirus replicative cycle were observed by electron microscopy in 12-day peripheral-blood lymphocyte cultures from 10 of 17 Chronic Fatigue Syndrome patients and not in controls. Attempts to identify a lymphoid phenotype containing these structures by immunogold labelling failed and the results of reverse-transcriptase assay of culture supernatants were equivocal. The study was blind and case-controlled, patients being paired with age, sex and ethnically matched healthy volunteers. Prescreening of subjects included the common metabolic and immunological disorders, functional conditions and a virus-screen against hepatitis B and C, Epstein-Barr Virus, Cytomegalovirus and Human Immunodeficiency Virus.

 

Source: Holmes MJ, Diack DS, Easingwood RA, Cross JP, Carlisle B. Electron microscopic immunocytological profiles in chronic fatigue syndrome. J Psychiatr Res. 1997 Jan-Feb;31(1):115-22. http://www.ncbi.nlm.nih.gov/pubmed/9201653