ME, or chronic fatigue syndrome, ‘not caused by virus’, say researchers – BBC News

December 22, 2010

From BBC News Online (story by Helen Briggs, health reporter). Updated version of story first published on 20 December,2010.

A new study has cast further doubt on the idea that a virus called XMRV causes chronic fatigue syndrome.

US scientists linked the condition, also known as ME, to a mouse-like virus in 2009 after finding it in blood samples.

Now, UK experts say the discovery was a “false positive”, caused by cross contamination in the lab.

The illness may still be caused by a virus, they say, but not the one at the centre of recent controversy.

“Our conclusion is quite simple: XMRV is not the cause of chronic fatigue syndrome,” said Professor Greg Towers, a Wellcome Trust senior research fellow at University College, London, who led the research.

“It is vital to understand that we are not saying chronic fatigue syndrome does not have a virus cause – we cannot answer that yet – but we know it is not this virus causing it.”

Mouse DNA

XMRV (xenotropic murine leukemia virus-related virus) is a virus found in mouse DNA.

It was discovered in 2006, and was later found in samples from some patients with prostate cancer and chronic fatigue syndrome.

This lead to suggestions that the virus might be the cause of these conditions.

A paper providing some evidence in support of a link between chronic fatigue syndrome and the virus was published in the leading journal Science last year.

In the latest work, the team, from London and the University of Oxford, used DNA sequencing methods to study XMRV.

They say their evidence, published in the journal Retrovirology, shows the virus found in patient samples arose from laboratory contamination.

What is more, they think it is unlikely that the virus could actually infect people.

Professor Tim Peto, consultant in infectious diseases at the University of Oxford, said the original paper in Science came as a great surprise to experts.

“There have now been a number of attempts which have failed to find the retrovirus in other samples, and this research suggests that in fact XMRV is probably a contamination from mouse DNA,” he said.

“These latest findings add to the evidence and it now seems really very, very unlikely that XMRV is linked to chronic fatigue syndrome.”

But the authors of the original research say they stand by their conclusions.

“Nothing that has been published to date refutes our data,” Dr Judy Mikovits, of the Whittemore Peterson Institute for Neuro-Immune Disease, said in a statement.

Dr Charles Shepherd, medical advisor for the ME Association, said patients should keep an open mind on the issue.

“The jury is still out,” he said.

4 thoughts on “ME, or chronic fatigue syndrome, ‘not caused by virus’, say researchers – BBC News”

  1. The BBC has let itself down with this hack job. As others keep repeating, this research published on Monday does not support the conclusion that MLV-related retroviruses is a contaminant. Nor does it support the claim it is a mouse virus.

    Why have the BBC not sort a quote from one of the retrovirologists involved in the positive studies. I know Shepherd can speak, but he is not a virologist.

  2. Professor Towers comes to an unscientific conclusion, methinks. It is way too early to say if HMRV’s (the family name of XMRV) is the cause or not of ME/CFS, but the papers published in Retrovirology on Monday only show that there has been contamination in those labs that found it. The Alter/Lo paper was very carefully put together to avoid contamination in their labs, as did the Cleveland Clinics lab, the National Cancer Institute lab and the Whittemore Peterson lab.

    The points that would tend to confirm the hypothesis that HMRV’s are implicated (which is as much as anyone is saying, at present) are, from my personal view:

    *Murine leukemia viruses cause similar neurological problems in mice
    *Some patients are getting better with antiretrovirals that tackle the retrovirus
    *There is a high percentage (±85%) of HMRV infection in PWME
    *I have always known this ME in me is an infection, and that my brain is inflamed
    *Eric Klein, Cleveland Clinic said today: We have reported XMRV integration in fresh frozen prostate tissue taken directly from patients at radical prostatectomy that has never been put in tissue culture and believe this is solid evidence of authentic human infection . See Dong et al PNAS 2007 and Kim et al. J Virol 2008

  3. TWiV host Vincent Racaniello has now retracted his previous article.

    Here is the before:
    Is XMRV a laboratory contaminant?

    Here is the after:
    XMRV and CFS – It’s not the end

    Also, the NHS choices website has changed the title of their article from ‘Chronic fatigue syndrome ‘not virus to ‘Chronic fatigue syndrome virus doubt’

  4. Not even John Coffin, co-author of 2 of the papers claims that the retrovirology papers in any way contradict or invalidate the previous work on XMRV (namely Lombardi et al. and Alter/Lo).

    I fear Greg Towers has over-stepped the mark here as to what is scientifically acceptable. To claim: “Our conclusion is quite simple: XMRV is not the cause of chronic fatigue syndrome” is both irresponsible and premature.

    Greg Towers should issue a retraction of his remarks as soon as possible, just as Prof. Racaniello of the Twiv blog already has (after falsely claiming this was the beginning of the end for the XMRV and CFS connection).

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