Skip directly to site content Skip directly to page options Skip directly to A-Z link Skip directly to A-Z link Skip directly to A-Z link
Volume 17, Number 2—February 2011
Letter

No Xenotropic Murine Leukemia Virus–related Virus Detected in Fibromyalgia Patients

On This Page
Figures
Article Metrics
13
citations of this article
EID Journal Metrics on Scopus

Cite This Article

To the Editor: Xenotropic murine leukemia virus–related virus (XMRV) is a recently described human retrovirus that has been associated with prostate cancer and chronic fatigue syndrome (CFS) (1,2). XMRV is similar to a classic murine endogenous leukemia retrovirus, murine leukemia virus (MLV), which infects strains of mice that do not express the specific viral receptor. XMRV is genetically close to, although differentiable from, MLV. The first evidence of its presence in humans was obtained by Urisman et al. in prostate cancer tissue (1). In 2009, Lombardi et al. (2) found XMRV sequences and specific antibody responses in 67% of a large group of patients with CFS in North America. This association was notable because XMRV sequences were found in only 4% of healthy controls. These results have generated controversy because several independent studies, mainly in Europe (35) but also in North America (6), have been unable to detect XMRV sequences in patients with CFS. Furthermore, a recent report from North America (7) appears to confirm the initial results by Lombardi et al. (2) in patients with CFS and expands the viral association to a wider variety of XMLV-related viruses that seem closer to polytropic mouse endogenous retroviruses.

Fibromyalgia is a multifactor condition characterized by widespread pain and diffuse tenderness. Although trauma and stress can worsen or even precipitate development of the syndrome, infections with certain viruses, including hepatitis C virus and HIV, have been associated with development of fibromyalgia (8). Nevertheless, fibromyalgia remains a disease of unknown etiology. Although CFS is a distinct entity, features shared by both diseases suggest that CFS and fibromyalgia represent the same underlying condition (9). Additionally, because they are often accompanied by a noticeable mental health effect (9), the presence of a potential neurotropic retroviral agent in both diseases could explain these similarities. Therefore, we studied the presence of XMRV and polytropic MLV–related retroviruses in a group of patients with fibromyalgia.

Figure

Thumbnail of Testing for xenotropic murine leukemia virus–related virus (XMRV) in patients with fibromyalgia. Lanes 1 and 13, molecular weight marker ΦX174RF HaeIII; lanes 2–5, hBG for patients 1–4 (primers: hBG-FI-170/hBG-RI-273 (103 bp); lanes 6–12, positive control (pcDNA3.1-XMRV-Vp62) 1,000 copies (lanes 6 and 10) and 100 copies (lanes 7–9 and 11–12); lane 6, primers gag 419F/1154R (735 bp); lane 7, primers gag MLV-GAG-I-F/MLV-GAG-I-R (413 bp); lane 8, primers gag MLV-NP116/MLV-NP117 (380 bp

Figure. Testing for xenotropic murine leukemia virus–related virus (XMRV) in patients with fibromyalgia. Lanes 1 and 13, molecular weight marker ΦX174RF HaeIII; lanes 2–5, hBG for patients 1–4 (primers: hBG-FI-170/hBG-RI-273 (103 bp);...

During January 2010, blood samples were collected from 15 patients in whom fibromyalgia had been previously diagnosed according to American College of Rheumatology criteria (www.rheumatology.org/practice/clinical/classification/fibromyalgia/1990_Criteria_for_Classification_Fibro.pdf). Ten healthy blood donors served as controls. For XMRV screening, we used DNA extracted from 400 μL of whole blood collected in EDTA tubes by the QIAamp DNA Mini Kit (QIAGEN, Hilden, Germany). Nested PCR was done by using 5 sets of primers corresponding to the gag (3) and env (2) regions of XMRV as described (2,3,7). The first round of PCR was conducted by using 500 ng of genomic DNA, equivalent to 7.5 × 104 nucleated blood cells, in a final volume of 50 μL, by using the Expand High Fidelity PCR System (Roche Applied Science, Basel, Switzerland). A second round of PCR was conducted under the same conditions by using 5 μL of the first reaction product. Details of the nested-PCR strategy were as follows: gag region was amplified by outer primers 419F and 1154R (2) and 3 sets of inner primers: XMRV-FI-441/XMRV-RI-566 (3), MLV-GAG-I-F/MLV-GAG-I-R, and MLV-NP116/MLV-NP117 (7). Nested PCR for env was performed by using outer primers 5922F and 6273R (2) and 2 sets of inner primers: 5922F/6173R and 5942F/6159R (7). Primers for human β-globin were used as positive controls of human DNA amplification (3). The full-length molecular viral clone VP62 (obtained through the National Institutes of Health AIDS Research and Reference Reagent Program [Rockville, MD, USA] from R.H. Silverman and B. Dong) (10) was used as a positive XMRV control. All samples were examined on a 2% agarose gel stained with ethidium bromide (Figure). The overall sensitivity of the nested PCR procedure, estimated by spiking VP62 into negative samples, was 1–10 copies per sample.

Using highly sensitive PCR tools and a multiple set of primers to detect xenotropic and polytropic MLV–related sequences, we found no evidence of MLV-related sequences in blood cells from fibromyalgia patients or controls. Our results agree with those from studies of CFS cohorts in Europe and North America that also failed to confirm XMRV in blood samples (36). Technical issues or geographic specificities probably could not account for such a difference; therefore, these negative results raise concerns about the role of XMRV in these syndromes. Nevertheless, with this relatively small population we cannot absolutely exclude an association of XMRV or polytropic MLV–related viruses with fibromyalgia. However, a proportion of fibromyalgia cases with XMRV >22% would be unlikely (3/15 cases, 95% confidence interval 0–3), which is clearly insufficient to support a significant association between XMRV and fibromyalgia.

Fibromyalgia does not appear to be associated with XMRV or polytropic MLV–related viruses. The role of these new agents in human disease, and specifically in CFS, remains to be clearly confirmed in multicenter and standardized studies.

Top

Acknowledgment

This study was supported by grants Fondo de Investigación (FIS)-PS09/01625 to G.H.-B. and Fundación para la Investigación Prevención del SIDA en España 36749, FIS-PI080806, and European Union Seventh Framework Programme CARMUSYS PITN-GA-2008213592 to R.D.

Top

Joanna Luczkowiak, Olalla Sierra, Jorge Juan González-Martín, Gabriel Herrero-Beaumont, and Rafael DelgadoComments to Author 
Author affiliations: Author affiliations: Hospital Universitario 12 de Octubre, Madrid, Spain (J. Luczkowiak, O. Sierra, R. Delgado); IIS-Fundación Jiménez Díaz, Madrid (J.J. González-Martín, G. Herrero-Beaumont)

Top

References

  1. Urisman  A, Molinaro  RJ, Fischer  N, Plummer  SJ, Casey  G, Klein  EA, Identification of a novel gammaretrovirus in prostate tumors of patients homozygous for R462Q RNASEL variant. PLoS Pathog. 2006;2:e25. DOIPubMedGoogle Scholar
  2. Lombardi  VC, Ruscetti  FW, Das  GJ, Pfost  MA, Hagen  KS, Peterson  DL, Detection of an infectious retrovirus, XMRV, in blood cells of patients with chronic fatigue syndrome. Science. 2009;326:5859. Epub 2009 Oct 8. DOIPubMedGoogle Scholar
  3. Erlwein  O, Kaye  S, McClure  MO, Weber  J, Wills  G, Collier  D, Failure to detect the novel retrovirus XMRV in chronic fatigue syndrome. PLoS ONE. 2010;5:e8519. DOIPubMedGoogle Scholar
  4. Groom  HC, Boucherit  VC, Makinson  K, Randal  E, Baptista  S, Hagan  S, Absence of xenotropic murine leukaemia virus–related virus in UK patients with chronic fatigue syndrome. Retrovirology. 2010;7:10. DOIPubMedGoogle Scholar
  5. van Kuppeveld  FJ, de Jong  AS, Lanke  KH, Verhaegh  GW, Melchers  WJ, Swanink  CM, 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;340:c1018. DOIPubMedGoogle Scholar
  6. Switzer  WM, Jia  H, Hohn  O, Zheng  H, Tang  S, Shankar  A, 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;7:57. DOIPubMedGoogle Scholar
  7. Lo  SC, Pripuzova  N, Li  B, Komaroff  AL, Hung  GC, Wang  R, 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;107:158749. DOIPubMedGoogle Scholar
  8. Buskila  D, Atzeni  F, Sarzi-Puttini  P. Etiology of fibromyalgia: the possible role of infection and vaccination. Autoimmun Rev. 2008;8:413. DOIPubMedGoogle Scholar
  9. McKay  PG, Duffy  T, Martin  CR. Are chronic fatigue syndrome and fibromyalgia the same? Implications for the provision of appropriate mental health intervention. J Psychiatr Ment Health Nurs. 2009;16:88494. DOIPubMedGoogle Scholar
  10. Dong  B, Kim  S, Hong  S, Das  GJ, Malathi  K, Klein  EA, An infectious retrovirus susceptible to an IFN antiviral pathway from human prostate tumors. Proc Natl Acad Sci U S A. 2007;104:165560. DOIPubMedGoogle Scholar

Top

Figure

Top

Cite This Article

DOI: 10.3201/eid1702.100978

Related Links

Top

Table of Contents – Volume 17, Number 2—February 2011

EID Search Options
presentation_01 Advanced Article Search – Search articles by author and/or keyword.
presentation_01 Articles by Country Search – Search articles by the topic country.
presentation_01 Article Type Search – Search articles by article type and issue.

Top

Comments

Please use the form below to submit correspondence to the authors or contact them at the following address:

Rafael Delgado, Servicio de Microbiología, Hospital Universitario 12 de Octubre. Avenida de Córdoba sn, Madrid 28041, Spain

Send To

10000 character(s) remaining.

Top

Page created: July 13, 2011
Page updated: July 13, 2011
Page reviewed: July 13, 2011
The conclusions, findings, and opinions expressed by authors contributing to this journal do not necessarily reflect the official position of the U.S. Department of Health and Human Services, the Public Health Service, the Centers for Disease Control and Prevention, or the authors' affiliated institutions. Use of trade names is for identification only and does not imply endorsement by any of the groups named above.
file_external