1 in 25 HEALTHY persons has XMRV ? (Contamination? Lombardi et al 2009)

[Psyma]

I'm unsure whether the results of this research have been proven to be unreliable,
due to contamination or other factors. I've searched but couldn't find.

http://www.sciencemag.org/content/326/5952/585.abstract

Chronic fatigue syndrome (CFS) is a debilitating disease of unknown etiology that is estimated to affect 17 million people worldwide. Studying peripheral blood mononuclear cells (PBMCs) from CFS patients, we identified DNA from a human gammaretrovirus, xenotropic murine leukemia virusrelated virus (XMRV), in 68 of 101 patients (67%) as compared to 8 of 218 (3.7%) healthy controls. Cell culture experiments revealed that patient-derived XMRV is infectious and that both cell-associated and cell-free transmission of the virus are possible. Secondary viral infections were established in uninfected primary lymphocytes and indicator cell lines after their exposure to activated PBMCs, B cells, T cells, or plasma derived from CFS patients. These findings raise the possibility that XMRV may be a contributing factor in the pathogenesis of CFS.

 

[Esther12]

I've searched but couldn't find.

Yeah, there aren't many threads on this one. Kind of passed us by.

Anyone know if there have been any follow up studies?

 

[Esther12]

PS: We still don't know. It's all a bit of a mess.

 

[Megan]

Really good to have a discussion on what has been found in the control populations. One of the things that is keeping my belief alive in regards to the XMRV/MLV findings is the level of consistency across the positive CFS, prostate and other studies in terms of the percentage of positives found in controls. By my calculations approximately 10 to date:

Published Studies:
1) Lombardi et at – 3.7% controls (8/218) vs 67% CFS patients (68/101)
2) Lo et al 2010 – 6.8% (3/44) controls vs. 86% CFS patients (32/37)

Reported at BPAC Meeting in December:
3) Mikovits UK study – 11% positive controls vs 78% CFS patients (after culture)
4) Hanson 20/20 study – 20% (4/20) positive controls and 70% (14/20) positive patients/’recovered’ patients. She indicates a higher control rate due to controls coming from an outbreak area and having contact with CFS patients.

Other Published Studies
6) Schlaberg/Singh et al 2009 – 4% controls (4/101) vs 23% prostate cancer patients (54/233) by IHC stain.
5) Fischer et al 2010 – 2-3% positive control patients (3/75) vs 10% immunosupressed patients (6/161)

Other Studies Reported at XMRV Conference in December
7) Das Gupta 2010 – 4.5% controls (1/22) vs 26 % prostate cancer patients (3/120) using urine test.

From Dr Sing Patient Documents:
8) XMRV detected in cervical fluid of 5-10% samples (raw numbers not stated)
9) XMRV detected in 7% of semen samples from 300 donors
10) CFS related - “Non-reactive samples (most healthy volunteers) did not contain antibodies to SU or pl5E (Fig. 13B)” [percentages or numbers not stated].

With the exception of the Hanson study (for which she has an explanation), all the rest are showing less than 10%, with only the UK study going just over at 11%.

Hard to believe they all could have been accidentally contaminated at similar rates, and all finding much higher percentages in patients over controls. I would think the argument that the patient samples were positive at higher rates due to ‘more handling’ is a bit of a weak argument given the number and consistency here – particularly given that a number of these studies were blinded prior to testing.

The other noticeable thing here is how few of the prostate cancer studies have involved control samples. There are more CFS studies than prostate ones with controls! How can the scientific community justify saying that there is a stronger association between prostate cancer and XMRV than between CFS and XMRV? Surely the presence of lower rates in control samples would be vital to any such claim?

 

[garcia]

Great post from Megan!

Also Dr Klein goes through the arguments for why the so-called "contamination papers" say absolutely nothing about the Lombardi et al. Science paper:

http://cfidsreport.com/News/11_Full_Interview_Eric_Klein_On_XMRV.html

 

[alex3619]

There is no question that XMRV is a real virus and can infect people. None. It is therefore overwhelmingly likely that it is present in some percentage of people. The debate is over the exact percentage, and whether it is directly or indirectly pathogenic.

If the percentage is in the range of published positive studies, and other studies cant find it at all in any people, then the probability is that it is a failure of the studies that can't find it. These are the so-called zero-zero studies.

Bye
Alex

 

[fla]

A good correlation vs causation joke

 

[Psyma]

maybe almost everyone has XMRV ?

and people with CFS have a weaker immune system.
for this reason a higher percentage of XMRV in their blood compared with healthy people...

which leads to a higher number of positive XMRV tests, compared with healthy people.
is that a possibility?

 

[alex3619]

Hi Psyma, it is indeed possibility that we often have XMRV because of our immune system. While this would rule out XMRV as causal, it would also prove we have major immune problems. Bye, Alex

 

[ukxmrv]

It was suggested right at the start when the Science paper was released that XMRV could be just more detectable in the blood of PWCFS. It's not a new or forgotten question.

We need the research to continue and find out these answers. No one knows.

Dr Singh with her research on cadavers may be able to start answering these questions. We need to look at organ reservoirs for the virus in healthy and CFS people.

As Alex pointed out just admitting that PWCFS do have immune system problems would be a big step forward. It was suggested in Oct 2009 when the original Science paper was published and at various times since then. I thought that it was significant that XMRV was trying to be explained away in this way. In the UK it is a big thing to admit.

Most of all we need a research group to do a proper replication of the Science paper.

 

[bullybeef]

maybe almost everyone has XMRV ?

Klein suggested as much is his talk the other week, but some as susceptible, like us.

BB