E2 ModerateModerate confidencePEM unclearCase-ControlPeer-reviewedMachine draft
No evidence of XMRV in prostate cancer cohorts in the Midwestern United States.
Sakuma, Toshie, Hué, Stéphane, Squillace, Karen A et al. · Retrovirology · 2011 · DOI
Quick Summary
Researchers tested prostate tissue and blood samples from men with and without prostate cancer to see if a virus called XMRV was present. They found a few samples that tested positive, but further investigation showed these were likely contaminated with mouse DNA from the laboratory rather than real virus. The study found no strong evidence that XMRV is actually infecting people's prostate tissue or blood.
Why It Matters
Early studies suggested XMRV might be associated with both prostate cancer and ME/CFS, creating concern about a potential infectious cause for these conditions. This rigorous negative study helps clarify that XMRV is unlikely to be a common pathogen in these diseases, reducing concern about a shared viral etiology while highlighting the importance of contamination controls in viral detection research.
Observed Findings
- Six samples tested positive by real-time PCR (5 prostate cancer, 1 benign tissue), but positive samples also contained mouse mitochondrial DNA, indicating laboratory contamination
- Sequences amplified from positive samples were nearly identical to endogenous mouse MLV sequences rather than XMRV
- Immunohisotochemistry with anti-XMRV antibody identified sporadic antigen-positive cells regardless of viral DNA detection status, suggesting non-specific reactivity
- No serum samples (159 prostate cancer + 201 controls) demonstrated strong XMRV-neutralizing antibodies at the 1:10 dilution threshold
- No statistical association was found between any detected viral sequences and prostate cancer status, tumor grade, or RNASEL R462Q mutation status
Inferred Conclusions
- Laboratory contamination with mouse DNA, rather than authentic XMRV infection, explains the positive PCR findings in this cohort
- Immunohisotochemical antigen detection is unreliable without corresponding molecular evidence of viral DNA and likely reflects non-specific antibody binding
- XMRV has no or very low prevalence in Midwestern prostate cancer and control populations
- Rigorous contamination controls and multiple complementary detection methods are essential for reliable retrovirals detection studies
Remaining Questions
What This Study Does Not Prove
This study does not prove that XMRV never exists in human disease or that it plays no role in ME/CFS—it only shows no convincing evidence in this particular Midwestern cohort. The study cannot exclude XMRV infection in other populations, different tissue types, or disease stages not represented in this sample. It does not address whether other related retroviruses might be involved in ME/CFS pathogenesis.
Tags
Biomarker:Autoantibodies
Method Flag:Exploratory Only
Metadata
- DOI
- 10.1186/1742-4690-8-23
- PMID
- 21447170
- Review status
- Machine draft
- Evidence level
- Single-study or moderate support from human research
- Last updated
- 8 April 2026
About the PEM badge: “PEM required” means post-exertional malaise was an explicit required diagnostic criterion for participant inclusion in this study — not that PEM was studied, observed, or discussed. Studies using criteria that do not require PEM (e.g. Fukuda, Oxford) are tagged “PEM not required”. How the atlas works →
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