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PLoS ONE: Swedish Study into Murine Gammaretrovirus Group G3


Senior Member
Cornwall England
12 October 2011: http://www.plosone.org/article/info%...l.pone.0024602

Amal Elfaitouri1, Xingwu Shao1, Johan Mattsson Ulfstedt1, Shaman Muradrasoli1, Agnes Blin Wiener1, Sultan Golbob1, Christina hrmalm1, Michael Matousek2, Olof Zachrisson2, Carl-Gerhard Gottfries2, Jonas Blomberg1*

1 Section of Clinical Virology, Department of Medical Sciences, University of Uppsala, Uppsala, Sweden, 2 Gottfries Clinic AB, Institute of Neuroscience and Physiology, University of Gothenburg, Gothenburg, Sweden


The recent report of gammaretroviruses of probable murine origin in humans, called xenotropic murine retrovirus related virus (XMRV) and human murine leukemia virus related virus (HMRV), necessitated a bioinformatic search for this virus in genomes of the mouse and other vertebrates, and by PCR in humans.


Three major groups of murine endogenous gammaretroviruses were identified. The third group encompassed both exogenous and endogenous Murine Leukemia Viruses (MLVs), and most XMRV/HMRV sequences reported from patients suffering from myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS).

Two sensitive real-time PCRs for this group were developed. The predicted and observed amplification range for these and three published XMRV/HMRV PCRs demonstrated conspicuous differences between some of them, partly explainable by a recombinatorial origin of XMRV.

Three reverse transcription real-time PCRs (RTQPCRs), directed against conserved and not overlapping stretches of env, gag and integrase (INT) sequences of XMRV/HMRV were used on human samples.

White blood cells from 78 patients suffering from ME/CFS, of which 30 patients also fulfilled the diagnostic criteria for fibromyalgia (ME/CFS/FM) and in 7 patients with fibromyalgia (FM) only, all from the Gothenburg area of Sweden. As controls we analyzed 168 sera from Uppsala blood donors. We controlled for presence and amplifiability of nucleic acid and for mouse DNA contamination.

To score as positive, a sample had to react with several of the XMRV/HMRV PCRs. None of the samples gave PCR reactions which fulfilled the positivity criteria.


XMRV/HMRV like proviruses occur in the third murine gammaretrovirus group, characterized here. PCRs developed by us, and others, approximately cover this group, except for the INT RTQPCR, which is rather strictly XMRV specific.

Using such PCRs, XMRV/HMRV could not be detected in PBMC and plasma samples from Swedish patients suffering from ME/CFS/FM, and in sera from Swedish blood donors.

Received: May 11, 2011; Accepted: August 15, 2011; Published: October 12, 2011

Am reading through it all now... :cool:


A very strong negative result, it seems.

They compared sequences to create a cluster of the family of retroviruses that include those reported to be associated with ME/CFS.

They used that aligned sequence cluster to develop three separate independent real-time state of the art PCR assays that cover the entire family of viruses.

They ran all three assays on samples from 78 ME/CFS patients, and 168 healthy controls.

They found no virus.


Senior Member
Cornwall England
Evening Lee,

I have to ask where does VP62 come into play with this one? I have seen that it does in the paper, but what do you make of all the claims that VP62 being a clone means that they were unable to see anything other than said XMRV clone i.e. that the 'real' XMRV's are not capable of being found?

Each time I post a comment now about the BWG results or anything, it seems I hit this same brick wall.

p.s. forgive the non-scientific language lol