retrovirus – Page 2 – American ME and CFS Society

No evidence of murine-like gammaretroviruses in CFS patients previously identified as XMRV-infected

Abstract:

Members of the gammaretroviruses–such as murine leukemia viruses (MLVs), most notably XMRV [xenotropic murine leukemia virus (X-MLV)-related virus–have been reported to be present in the blood of patients with chronic fatigue syndrome (CFS).

We evaluated blood samples from 61 patients with CFS from a single clinical practice, 43 of whom had previously been identified as XMRV-positive. Our analysis included polymerase chain reaction and reverse transcription polymerase chain reaction procedures for detection of viral nucleic acids and assays for detection of infectious virus and virus-specific antibodies.

We found no evidence of XMRV or other MLVs in these blood samples. In addition, we found that these gammaretroviruses were strongly (X-MLV) or partially (XMRV) susceptible to inactivation by sera from CFS patients and healthy controls, which suggested that establishment of a successful MLV infection in humans would be unlikely. Consistent with previous reports, we detected MLV sequences in commercial laboratory reagents. Our results indicate that previous evidence linking XMRV and MLVs to CFS is likely attributable to laboratory contamination.

Comment in: Prostate cancer: XMRV–contaminant, not cause? [Nat Rev Urol. 2011]

Source: Knox K, Carrigan D, Simmons G, Teque F, Zhou Y, Hackett J Jr, Qiu X, Luk KC, Schochetman G, Knox A, Kogelnik AM, Levy JA. No evidence of murine-like gammaretroviruses in CFS patients previously identified as XMRV-infected. Science. 2011 Jul 1;333(6038):94-7. doi: 10.1126/science.1204963. Epub 2011 May 31. https://www.ncbi.nlm.nih.gov/pubmed/21628393

Absence of XMRV retrovirus and other murine leukemia virus-related viruses in patients with chronic fatigue syndrome

Abstract:

Chronic fatigue syndrome (CFS) is a multisystem disorder characterized by prolonged and severe fatigue that is not relieved by rest. Attempts to treat CFS have been largely ineffective primarily because the etiology of the disorder is unknown. Recently, CFS has been associated with xenotropic murine leukemia virus-related virus (XMRV) as well as other murine leukemia virus (MLV)-related viruses, though not all studies have found these associations. We collected blood samples from 100 CFS patients and 200 self-reported healthy volunteers from the same geographical area. We analyzed these in a blind manner using molecular, serological, and viral replication assays. We also analyzed samples from patients in the original study that reported XMRV in CFS patients. We did not find XMRV or related MLVs either as viral sequences or infectious viruses, nor did we find antibodies to these viruses in any of the patient samples, including those from the original study. We show that at least some of the discrepancy with previous studies is due to the presence of trace amounts of mouse DNA in the Taq polymerase enzymes used in these previous studies. Our findings do not support an association between CFS and MLV-related viruses, including XMRV, and the off-label use of antiretrovirals for the treatment of CFS does not seem justified at present.

Source: Shin CH, Bateman L, Schlaberg R, Bunker AM, Leonard CJ, Hughen RW, Light AR, Light KC, Singh IR. Absence of XMRV retrovirus and other murine leukemia virus-related viruses in patients with chronic fatigue syndrome. J Virol. 2011 Jul;85(14):7195-202. doi: 10.1128/JVI.00693-11. Epub 2011 May 4. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3126563/ (Full article)

Analysis of cerebrospinal fluid from chronic fatigue syndrome patients for multiple human ubiquitous viruses and xenotropic murine leukemia-related virus

Abstract:

Recent reports showed many patients with chronic fatigue syndrome (CFS) harbor a retrovirus, xenotropic murine leukemia-related virus (XMRV), in blood; other studies could not replicate this finding. A useful next step would be to examine cerebrospinal fluid, because in some patients CFS is thought to be a brain disorder. Finding a microbe in the central nervous system would have greater significance than in blood because of the integrity of the blood-brain barrier. We examined cerebrospinal fluid from 43 CFS patients using polymerase chain reaction techniques, but did not find XMRV or multiple other common viruses, suggesting that exploration of other causes or pathogenetic mechanisms is warranted.

Comment in:

Reply to Schutzer et al. [Ann Neurol. 2011]

Extraordinary claims require extraordinary evidence. [Ann Neurol. 2011]

Source: Schutzer SE, Rounds MA, Natelson BH, Ecker DJ, Eshoo MW. Analysis of cerebrospinal fluid from chronic fatigue syndrome patients for multiple human ubiquitous viruses and xenotropic murine leukemia-related virus. Ann Neurol. 2011 Apr;69(4):735-8. doi: 10.1002/ana.22389. Epub 2011 Apr 6. https://www.ncbi.nlm.nih.gov/pubmed/21472770

No association of xenotropic murine leukemia virus-related virus with prostate cancer or chronic fatigue syndrome in Japan

Abstract:

BACKGROUND: The involvement of xenotropic murine leukemia virus-related virus (XMRV) in prostate cancer (PC) and chronic fatigue syndrome (CFS) is disputed as its reported prevalence ranges from 0% to 25% in PC cases and from 0% to more than 80% in CFS cases. To evaluate the risk of XMRV infection during blood transfusion in Japan, we screened three populations–healthy donors (n = 500), patients with PC (n = 67), and patients with CFS (n = 100)–for antibodies against XMRV proteins in freshly collected blood samples. We also examined blood samples of viral antibody-positive patients with PC and all (both antibody-positive and antibody-negative) patients with CFS for XMRV DNA.

RESULTS: Antibody screening by immunoblot analysis showed that a fraction of the cases (1.6-3.0%) possessed anti-Gag antibodies regardless of their gender or disease condition. Most of these antibodies were highly specific to XMRV Gag capsid protein, but none of the individuals in the three tested populations retained strong antibody responses to multiple XMRV proteins. In the viral antibody-positive PC patients, we occasionally detected XMRV genes in plasma and peripheral blood mononuclear cells but failed to isolate an infectious or full-length XMRV. Further, all CFS patients tested negative for XMRV DNA in peripheral blood mononuclear cells.

CONCLUSION: Our data show no solid evidence of XMRV infection in any of the three populations tested, implying that there is no association between the onset of PC or CFS and XMRV infection in Japan. However, the lack of adequate human specimens as a positive control in Ab screening and the limited sample size do not allow us to draw a firm conclusion.

Source: Furuta RA, Miyazawa T, Sugiyama T, Kuratsune H, Ikeda Y, Sato E, Misawa N, Nakatomi Y, Sakuma R, Yasui K, Yamaguti K, Hirayama F. No association of xenotropic murine leukemia virus-related virus with prostate cancer or chronic fatigue syndrome in Japan. Retrovirology. 2011 Mar 17;8:20. doi: 10.1186/1742-4690-8-20. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3065418/ (Full article)

Investigation into the presence of and serological response to XMRV in CFS patients

Abstract:

The novel human gammaretrovirus xenotropic murine leukemia virus-related virus (XMRV), originally described in prostate cancer, has also been implicated in chronic fatigue syndrome (CFS). When later reports failed to confirm the link to CFS, they were often criticised for not using the conditions described in the original study. Here, we revisit our patient cohort to investigate the XMRV status in those patients by means of the original PCR protocol which linked the virus to CFS. In addition, sera from our CFS patients were assayed for the presence of xenotropic virus envelope protein, as well as a serological response to it. The results further strengthen our contention that there is no evidence for an association of XMRV with CFS, at least in the UK.

Source: Erlwein O, Robinson MJ, Kaye S, Wills G, Izui S, Wessely S, Weber J, Cleare A, Collier D, McClure MO. Investigation into the presence of and serological response to XMRV in CFS patients. PLoS One. 2011 Mar 9;6(3):e17592. doi: 10.1371/journal.pone.0017592. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3052320/ (Full article)

Serologic and PCR testing of persons with chronic fatigue syndrome in the United States shows no association with xenotropic or polytropic murine leukemia virus-related viruses

Abstract:

In 2009, a newly discovered human retrovirus, xenotropic murine leukemia virus (MuLV)-related virus (XMRV), was reported by Lombardi et al. in 67% of persons from the US with chronic fatigue syndrome (CFS) by PCR detection of gag sequences. Although six subsequent studies have been negative for XMRV, CFS was defined more broadly using only the CDC or Oxford criteria and samples from the US were limited in geographic diversity, both potentially reducing the chances of identifying XMRV positive CFS cases. A seventh study recently found polytropic MuLV sequences, but not XMRV, in a high proportion of persons with CFS. Here we tested blood specimens from 45 CFS cases and 42 persons without CFS from over 20 states in the United States for both XMRV and MuLV. The CFS patients all had a minimum of 6 months of post-exertional malaise and a high degree of disability, the same key symptoms described in the Lombardi et al. study. Using highly sensitive and generic DNA and RNA PCR tests, and a new Western blot assay employing purified whole XMRV as antigen, we found no evidence of XMRV or MuLV in all 45 CFS cases and in the 42 persons without CFS. Our findings, together with previous negative reports, do not suggest an association of XMRV or MuLV in the majority of CFS cases.

Source: Satterfield BC, Garcia RA, Jia H, Tang S, Zheng H, Switzer WM. Serologic and PCR testing of persons with chronic fatigue syndrome in the United States shows no association with xenotropic or polytropic murine leukemia virus-related viruses. Retrovirology. 2011 Feb 22;8:12. doi: 10.1186/1742-4690-8-12. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3050813/ (Full article)

No evidence for XMRV in German CFS and MS patients with fatigue despite the ability of the virus to infect human blood cells in vitro

Abstract:

BACKGROUND: Xenotropic murine leukemia virus-related virus (XMRV), a novel human retrovirus originally identified in prostate cancer tissues, has recently been associated with chronic fatigue syndrome (CFS), a disabling disease of unknown etiology affecting millions of people worldwide. However, several subsequent studies failed to detect the virus in patients suffering from these illnesses or in healthy subjects. Here we report the results of efforts to detect antibody responses and viral sequences in samples from a cohort of German CFS and relapsing remitting multiple sclerosis (MS) patients with fatigue symptoms.

METHODOLOGY: Blood samples were taken from a cohort of 39 patients fulfilling the Fukuda/CDC criteria (CFS), from 112 patients with an established MS diagnosis and from 40 healthy donors. Fatigue severity in MS patients was assessed using the Fatigue Severity Scale (FSS). Validated Gag- and Env-ELISA assays were used to screen sera for XMRV antibodies. PHA-activated PBMC were cultured for seven days in the presence of IL-2 and DNA isolated from these cultures as well as from co-cultures of PBMC and highly permissive LNCaP cells was analyzed by nested PCR for the presence of the XMRV gag gene. In addition, PBMC cultures were exposed to 22Rv1-derived XMRV to assess infectivity and virus production.

CONCLUSION: None of the screened sera from CFS and MS patients or healthy blood donors tested positive for XMRV specific antibodies and all PBMC (and PBMC plus LNCaP) cultures remained negative for XMRV sequences by nested PCR. These results argue against an association between XMRV infection and CFS and MS in Germany. However, we could confirm that PBMC cultures from healthy donors and from CFS patients can be experimentally infected by XMRV, resulting in the release of low levels of transmittable virus.

Source: Hohn O, Strohschein K, Brandt AU, Seeher S, Klein S, Kurth R, Paul F, Meisel C, Scheibenbogen C, Bannert N. No evidence for XMRV in German CFS and MS patients with fatigue despite the ability of the virus to infect human blood cells in vitro. PLoS One. 2010 Dec 22;5(12):e15632. doi: 10.1371/journal.pone.0015632. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3008728/ (Full article)

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

Abstract:

In October 2009, we reported the first direct isolation of infectious xenotropic murine leukemia virus-related virus (XMRV). In that study, we used a combination of biological amplification and molecular enhancement techniques to detect XMRV in more than 75% of 101 patients with chronic fatigue syndrome (CFS). Since our report, controversy arose after the publication of several studies that failed to detect XMRV infection in their CFS patient populations. In this addenda, we further detail the multiple detection methods we used in order to observe XMRV infection in our CFS cohort. Our results indicate that PCR from DNA of unstimulated peripheral blood mononuclear cells is the least sensitive method for detection of XMRV in subjects’ blood. We advocate the use of more than one type of assay in order to determine the frequency of XMRV infection in patient cohorts in future studies of the relevance of XMRV to human disease.

Source: Mikovits JA, Lombardi VC, Pfost MA, Hagen KS, Ruscetti FW. Detection of an infectious retrovirus, XMRV, in blood cells of patients with chronic fatigue syndrome. Virulence. 2010 Sep-Oct;1(5):386-90. doi: 10.4161/viru.1.5.12486. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3073172/ (Full article)

Failure to detect Xenotropic murine leukaemia virus-related virus in Chinese patients with chronic fatigue syndrome

Abstract:

BACKGROUND: Recent controversy has surrounded the question of whether xenotropic murine leukaemia virus-related virus (XMRV) contributes to the pathogenesis of chronic fatigue syndrome (CFS). To investigate the question in a Chinese population, 65 CFS patients and 85 blood donor controls were enrolled and multiplex real-time PCR or reverse transcriptase PCR (RT-PCR) was developed to analyze the XMRV infection status of the study participants. The assay was standardized by constructing plasmid DNAs and armored RNAs as XMRV standards and competitive internal controls (CICs), respectively.

RESULTS: The sensitivities of the multiplex real-time PCR and RT-PCR assays were 20 copies/reaction and 10 IU/ml, respectively, with 100% specificity. The within-run precision coefficient of variation (CV) ranged from 1.76% to 2.80% and 1.70% to 2.59%, while the between-run CV ranged from 1.07% to 2.56% and 1.06% to 2.74%. XMRV was not detected in the 65 CFS patients and 65 normal individuals out of 85 controls.

CONCLUSIONS: This study failed to show XMRV in peripheral blood mononuclear cells (PBMCs) and plasma of Chinese patients with CFS. The absence of XMRV nucleic acids does not support an association between XMRV infection and the development of CFS in Chinese.

Source: Hong P, Li J, Li Y. Failure to detect Xenotropic murine leukaemia virus-related virus in Chinese patients with chronic fatigue syndrome. Virol J. 2010 Sep 13;7:224. doi: 10.1186/1743-422X-7-224. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2945957/ (Full article)

Mouse retroviruses and chronic fatigue syndrome: Does X (or P) mark the spot?

Five years ago, a retrovirus resembling a murine leukemia virus (MLV) was found in patients with prostate cancer (1), and last year, a similar gammaretrovirus was identified in patients with chronic fatigue syndrome (CFS) (2). The agent was named xenotropic MLV-related virus (XMRV), because its env gene was nearly identical to that of xenotropic MLV, an infectious endogenous MLV that preferentially infects cells from foreign species, including humans (Fig. 1A) (3). The two reports struck a common chord, because the viral sequences found in prostate cancer and CFS were nearly identical. A second common theme emerged in reports from Europe that XMRV was rarely found, if at all, in prostate-cancer samples or patients with CFS; however, other investigators confirmed the presence of XMRV in prostate-cancer samples from North America (4). Although a recent report from the Centers for Disease Control and Prevention (CDC) did not find a link between XMRV and CFS (5), distinct MLV-related sequences are found in serial samples collected from the mid-1990s to 2010 from patients with CFS reported in the study by Lo et al. (6) in PNAS. However, the reasons for the current geographical restriction and the source of the infection are baffling.

You can read the rest of this comment here: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2936611/

Comment on: Detection of MLV-related virus gene sequences in blood of patients with chronic fatigue syndrome and healthy blood donors. [Proc Natl Acad Sci U S A. 2010]

Source: Courgnaud V1, Battini JL, Sitbon M, Mason AL. Mouse retroviruses and chronic fatigue syndrome: Does X (or P) mark the spot? Proc Natl Acad Sci U S A. 2010 Sep 7;107(36):15666-7. doi: 10.1073/pnas.1007944107. Epub 2010 Aug 23. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2936611/ (Full article)