Zhou et al: Lack of xenotropic MLV-related virus and/or MLV detection in blood donors

[Tony Mach]

Development and application of a high-throughput microneutralization assay:
lack of xenotropic murine leukemia virus-related virus and/or murine leukemia virus detection in blood donors.

http://www.ncbi.nlm.nih.gov/pubmed/22239212

Transfusion. 2012 Feb;52(2):332-42. doi: 10.1111/j.1537-2995.2011.03519.x.
Zhou Y, Steffen I, Montalvo L, Lee TH, Zemel R, Switzer WM, Tang S,
Jia H, Heneine W, Winkelman V, Tailor CS, Ikeda Y, Simmons G.

Source
From the Blood Systems Research Institute, and the Department of Laboratory Medicine, University of California at San Francisco, San Francisco, California;

Laboratory Branch, Division of HIV/AIDS Prevention, Centers for Disease Control and Prevention, Atlanta, Georgia;

Creative Testing Solutions, Tempe, Arizona;

the Hospital for Sick Children, Toronto, Ontario, Canada;

and the Department of Molecular Medicine, Mayo Clinic, Rochester, Minnesota.

Abstract

BACKGROUND:
Xenotropic murine leukemia virus (MLV)-related virus (XMRV) and other related MLVs have been described with chronic fatigue syndrome and certain types of prostate cancer.

In addition, prevalence rates as high as 7% have been reported in blood donors, raising the risk of transfusion-related transmission.

Several laboratories have utilized microneutralization assays as a surrogate marker for detection of anti-MLV serologic responses-with up to 25% of prostate cancer patients reported to harbor neutralizing antibody responses.

STUDY DESIGN AND METHODS:
We developed a high-throughput microneutralization assay for research studies on blood donors using retroviral vectors pseudotyped with XMRV-specific envelopes.

Infection with these pseudotypes was neutralized by sera from both macaques and mice challenged with XMRV, but not preimmune serum.

A total of 354 plasma samples from blood donors in the Reno/Tahoe area were screened for neutralization.

RESULTS:
A total of 6.5% of donor samples gave moderate neutralization of XMRV, but not control pseudotypes.

However, further testing by Western blot revealed no evidence of antibodies against MLVs in any of these samples.

Furthermore, no evidence of infectious virus or viral nucleic acid was observed.

CONCLUSION:

A microneutralization assay was developed for detection of XMRV and can be applied in a high-throughput format for large-scale studies.

Although a proportion of blood donors demonstrated the ability to block XMRV envelope-mediated infection, we found no evidence that this inhibition was mediated by specific antibodies elicited by exposure to XMRV or MLV.

It is likely that this moderate neutralization is mediated through another, nonspecific mechanism.

I gave each sentence a new paragraph and highlighted one sentence I deemed important.

via the CO-CURE mailinglist

 

[Tony Mach]

We developed a high-throughput microneutralization assay for research studies on blood donors using retroviral vectors pseudotyped with XMRV-specific envelopes.

Infection with these pseudotypes was neutralized by sera from both macaques and mice challenged with XMRV, but not preimmune serum.

What they did was very clever, as far as I understand it.

First, they developed a neutralization assay (NT). There are several ways to look if a virus was (or still) is present in a person. You can look for the virus's RNA/DNA via PCR, you can try to culture it. Or you can look to see if antibodies to that virus are present (IgA, IgM, IgG...). And then there are neutralization assays, where you match up the serum ("blood") with the viruses, to see if the serum "knocks out" the virus. The NT assay works wether the virus is present or not, simply because if you were infected by a virus, your body will produce antibodies even if the virus is gone (or "hides" in the tissue or whatever).

And secondly, they tested their NT assay against the serum from macaques and mice, both challenged with XMRV and unchallenged. So they had pretty good positive and negative controls.

I don't know [STRIKE]if anybody[/STRIKE] who else went this route before. From the abstract, this seems to be a very solid study.

 

[Tony Mach]

This just leaves one questions for all that believe that XMRV/"HGRV"/WHATEVER is spreading in people: Where are all the healthy carriers?

 

[Firestormm]

Very interesting Tony. Thanks.

So this takes the previous macaque studies that stage further? Which is I suspect what Abbie and others were saying was needed before certain papers left their summations hanging with 'what if's?' that others have taken to mean - its' still there in the tissue: http://forums.phoenixrising.me/show...in-Pigtailed-Macaques/page4&highlight=macaque

Will try to get hold of the full paper I think.

 

[natasa778]

Bottom line is that they haven't a faintest clue what caused antibody reaction to XMRV in 23 blood donors. Not very reassuring.

 

[alex3619]

Hi natasha778, from my reading of the abstract the neutralization was not antibody based, mechanism unknown. Since it is unknown, we have no way to assess the possibility of cross-reactivity or other complications. In short, its a mystery. However it really was an elegant study from what little I have seen. I would like to see this kind of effort go into more studies. Bye, Alex

 

[natasa778]

yes my bad should have said neutralisation.

 

[Mark]

Bottom line is that they haven't a faintest clue what caused antibody reaction to XMRV in 23 blood donors. Not very reassuring.

Quite so: for me, the most intriguing part of this abstract was the unexplained neutralisation (but not known MLV-antibody) response:

Background
...prevalence rates as high as 7% have been reported in blood donors, raising the risk of transfusion-related transmission. Several laboratories have utilized microneutralization assays as a surrogate marker for detection of anti-MLV serologic responses-with up to 25% of prostate cancer patients reported to harbor neutralizing antibody responses.

Results
...
A total of 6.5% of donor samples gave moderate neutralization of XMRV, but not control pseudotypes.

However, further testing by Western blot revealed no evidence of antibodies against MLVs in any of these samples.
...

This seems to be saying that 6.5% of donor samples have some kind of neutralising response to XMRV - and as Tony noted:

neutralization assays, where you match up the serum ("blood") with the viruses, to see if the serum "knocks out" the virus. The NT assay works wether the virus is present or not, simply because if you were infected by a virus, your body will produce antibodies even if the virus is gone (or "hides" in the tissue or whatever)

Yet despite detecting a neutralising response to XMRV, they were unable to find any evidence of antibodies against MLVs in those samples. So this appears to present evidence that 6.5% of donor samples had a specific neutralising response to XMRV, yet the mechanism for this is unclear because they were unable to detect antibodies.

So to me, this suggests that there is some unknown or unusual mechanism present here, apparently suggesting that 6.5% of donors may indeed have been exposed to XMRV and show residual evidence of a neutralising response to it, even though that can't be detected as presence of the virus or presence of known antibodies - or at least, not when using the tests that they expected to find those antibodies.

It looks like that 6.5% neutralising response really needs to be explained.

 

[natasa778]

It looks like that 6.5% neutralising response really needs to be explained.

Especially since it matches earlier reported rates of xmrv prevalence in blood donors/healthy population !!

 

[Ecoclimber]

What is interesting is that they didn't shoot down Lo's research. They did leave the door open.

"Nonetheless, the findings of Lo and colleagues raised the hypothesis that while XMRV itself is clearly a laboratory contaminant, the serologic responses detected in Lombardi and coworkers may be due to infection by other MLVs or gammaretroviruses."

Eco

 

[currer]

As we know that the antibody response to MLVs does not persist past the initial phase in infected individuals -- could this "neutralising reaction" be what the immune system is left with?

If MLVs disrupt the normal functioning of the immune system, who is to say what a "normal" immune response in a chronically infected individual should look like.???
Remember the macaques, who lost their antibody response but were still infected. A chronic infection which is in the immune system and persists for years - what defences is the body likely to be left with to use against such an unusual invader?

In which case the percentages quoted tally well with the previous figures for infection in the population and detection of MLVs.

Incidentally, Eco, you are uncharacteristically favourable to retroviral infections all of a sudden. Could it be you have heard something and want to tell us all about it?

 

[barbc56]

What is interesting is that they didn't shoot down Lo's research. They did leave the door open.

"Nonetheless, the findings of Lo and colleagues raised the hypothesis that while XMRV itself is clearly a laboratory contaminant, the serologic responses detected in Lombardi and coworkers may be due to infection by other MLVs or gammaretroviruses."

Eco

If I am interpreting what you are saying correctly, you are saying the samples were not necessarily responding to XMRV but something else such as background viruses?

From what I have read, Lo cast a bigger net and got an even larger response?

Let me know if I have interpreted this correctly or not.

Thanks, Eco.

Barb C.:>)

 

[currer]

Hi barb,

Dr Mikovits has repeatedly stated that she can detect a wider range of PMRVs.
Her talk, which I attended in May 2010 at the IiME conference was about the range of PMRV viruses she could find, and the antibody reactions which suggested an MRV type C retrovirus. She could not get this subsequent research of hers published. I think this refusal to allow her to modify her ideas in the light of later findings was a deliberate attempt to restrict her to a false position so that her findings could be easily publicly derided and denied.

VP62 XMRV was withdrawn from Lombardi with her agreement but she stood by the remainder of her findings.

For about a year now we have known that "XMRV" is more likely to be a PMRV, in agreement with Alter and Lo's findings, which did not find "XMRV" but only PMRVs. Lo did not find "a larger response" but got roughly the same percentages as Mikovits as positives.

It looks as if Eco may now think this, as his last couple of posts have shown a distinct warming to this idea, even enthusiasm for it!

I note that Singh's work on prostate cancer is still unretracted. The double standard here irritates me.

 

[Bob]

I note that Singh's work on prostate cancer is still unretracted. The double standard here irritates me.

Switzer's positive paper is unretracted as well.

But, as we know, from these examples, and from the PACE Trial, the peer review process has absolutely little to do with what gets published and retracted. It's mostly politics.

 

[Firestormm]

Morning,

You know I have read several review papers concerning XMRV and they all say similar things about the prostate cancer papers in that they believe contamination is the most likely explanation.

I have said elsewhere - including RetractionWatch - that it would make sense from my perspective (as a non-scientist) for those papers to also be retracted, but perhaps that isn't part of the process?

I don't know. It's all beyond my comprehension. I mean unless the authors themselves retract then it would be the Journal editors I suppose; unless 'science' has generally accepted the above conclusion? I mean not all papers are retracted when 'science' moves on - are they?

Still, I'm sure we'll hear more about it all in due course.

Edit:

e.g. Sfanos et al XMRV and Prostate Cancer A 'Final' Perspective 10 January 2012. It's on the forum somewhere I believe...

 

[barbc56]

What I meant is if you cast a wider net, you are even more likely to get contamination.

If Mikovits didn't get a paper published, it would most likely mean it was not worth publishing. If only they had more carefully reviewed the original study. Sigh. I really hate conspiracy theories when there might be a simpler explanation.

Barb C.

 

[Bob]

If Mikovits didn't get a paper published, it would most likely mean it was not worth publishing.

But you don't have any evidence for this do you? Nor any factual insight into it? So it's actually just a random assertion.

I really hate conspiracy theories when there might be a simpler explanation.

Do you really think that politics is never at play in the closed old-boy's network of scientific publishing?

It seems extremelly obvious to me that not many editors would want to publish Mikovits at the moment, purely because of politics. No editors would want to get hauled through what the Science editors have gone through in the past couple of years, and would probably want to steer clear of extreme negative controversy.

So the simplest explanation could actually be 'politics'.


I've just noticed that the only positive XMRV studies that seem to have been published recently, are the ones that declare loudly that there is no 'association' (with anything) in the title of the paper. So I think that 'explicitly' positive XMRV studies might not be wanted for publication anywhere at the moment.

If only they had more carefully reviewed the original study.

It wouldn't have made any difference. They don't peer review with a great deal of depth because they have to rely on the scientists' physical research, and often seem to rely on the analysis as well. Very many published papers are weak, lead to a dead end, and are superseded with newer & contradictory science, but they don't get retracted.

Also, notice that no other XMRV studies have been retracted. This must be purely because of politics, if the Lombardi study is so worthy of retraction.


As a definite example of politics, in the case of the 'PACE Trial', some of the analysis, and an editorial, has been shown to be completely flawed and misleading, but no correction or partial retraction has taken place.

The PACE Trial didn't go through a proper pier review process. The editors have admitted that they relied on the authors's statistical analysis, and the paper was 'fast tracked' for publication (i.e. old-boys network). And even after the editors have been made aware that the analysis is flawed, it still it hasn't been properly peer reviewed, corrected or partially retracted. Politics!


I'm not generally a conspiracy theorist. But in the case of CFS/ME, we absolutely know that there have been conspiracies going on for thirty years or so, on both sides of the Atlantic.

Wake up!

Sigh.

Deep breaths Barb!

 

[barbc56]

"Most likely" means just what it says. Do you have proof there is a conspracy against her?

IMHO, I think many "conspiracies" can really be explained by human error, acting according to what is known at the time and the nature of bureaucracies, to name a few. Not saying they never exist but haven't seen anything re ME/CFS so far where the above might be a more realistic reason that something happens. While these events are frustrating, no quarrle there, I don't often understand why a leap of logic to a conspiracy theory seems reasonable. Politics can play a role but not to the extent many have tried to explain here.

Our brains try to make sense of things and it's often influenced by our perception.

Had my coffee!! Breath in, breath out. That advice is spot on. Sometimes we all need to step away just a bit from our emotions and come back to analysize things at a later time.

Take care.

Barb C.

Another explanation for a conspiracy theory is sometimes the people involved in what think looks nefarious, are simply clueless about what is going on.

 

[Bob]

IMHO, I think many "conspiracies" can really be explained by human error, acting according to what is known at the time and the nature of bureaucracies, to name a few. Not saying they never exist but haven't seen anything re ME/CFS so far where the above might be a more realistic reason that something happens. While these events are frustrating, no quarrle there, I don't often understand why a leap of logic to a conspiracy theory seems reasonable. Politics can play a role but not to the extent many have tried to explain here.

...

Another explanation for a conspiracy theory is sometimes the people involved in what think looks nefarious, are simply clueless about what is going on.

I'm not refering to large-scale global conspiracies where entire governments and scientific communities are actively and consciously conspiring against ME patients.

There are different types of conspiracies, and by definition, it takes a minimum of only two people to conspire together.

The sort of conspiracy that I'm talking about is where a small group of people conspire, either consciously or unconsciously, to promote or suppress a point-of-view that is only in their own interests to do so.

So in the case of the USA, the CDC were found to be diverting funds away from CFS research. This was a conspiracy, because it took more than one person to conspire together to make it happen. Also, the CDC obviously were not taking CFS seriously for a great number of years, and the group-think at the CDC seemed to be that CFS was not a condition to be taken seriously. This was a conspiracy of sorts as well.

In the UK, there is a conspiracy within the psychiatric lobby to make CFS/ME recognised as a psychiatric disease that should be treated with psychological therapies based on a model of disease in which CFS is caused by a fear of exercise etc. We only have to look at the difference between the actual results of the PACE Trial, and the manipulated reported results for evidence of this conspiracy. Whether of not these psychiatrists believe that their points-of-view are the truth, or whether they are deeply corrupt people, I don't know, but whichever it is, it is still a conspiracy of sorts.

It seems with CFS/ME that the widescale corruption is allowed to happen because of widespread ignorance about the nature of the disease, which allows a disproportionately large amount of influence to rest in the hands of a small number of self-appointed-experts who corrupt the field.

Anyone who has insight into the history of ME must surely understand that groups of people have, and continue to, conspire to influence (corrupt) the field of ME, whatever the shape and nature of that conspiracy.

 

[barbc56]

So in the case of the USA, the CDC were found to be diverting funds away from CFS research. This was a conspiracy, because it took more than one person to conspire together to make it happen. Also, the CDC obviously were not taking CFS seriously for a great number of years, and the group-think at the CDC seemed to be that CFS was not a condition to be taken seriously. This was a conspiracy of sorts as well.

Wow, we do have different definitions of conspiracy. Your above example, is about crooks who stole money. It has nothing to do with ME and probably would have happened if the person(s), can't remember name(s), had been in a similar situation. This type of things happen with institutions.

In the UK, there is a conspiracy within the psychiatric lobby to make CFS/ME recognised as a psychiatric disease that should be treated with psychological therapies based on a model of disease in which CFS is caused by a fear of exercise etc. We only have to look at the difference between the actual results of the PACE Trial, and the manipulated reported results for evidence of this conspiracy. Whether of not these psychiatrists believe that their points-of-view are the truth, or whether they are deeply corrupt people, I don't know, but whichever it is, it is still a conspiracy of sorts.

While I do not like things like the psychological definitions prevalent in the UK and think there are flaws in the results of the PACE trial, I truely believe these people believe what they are saying. This is sad but not a conspiracy. Misguided is the word that comes to mind. It needs to be countered with appropriate debate.

It seems with CFS/ME that the widescale corruption is allowed to happen because of widespread ignorance about the nature of the disease, which allows a disproportionately large amount of influence to rest in the hands of a small number of self-appointed-experts who corrupt the field.

This is an opinion. Do you have a concrete example? I go by analyzing the science. I read the literature, know how to read and interpret journal articles. This is my training. I have always been someone who analyzes situations, questions authority and looks at all sides of an issue before coming to a conclusion and not the other way around.


Though, now that I think about it, some online forums might fall under your above definition.

Anyone who has insight into the history of ME must surely understand that groups of people have, and continue to, conspire to influence (corrupt) the field of ME, whatever the shape and nature of that conspiracy.

Does insight involve calling people names when no other point comes to mind?

IMHO, The world is much more complicated than how you are explaining it. The world is not black and white. It's shades of gray.

Now let's get back on topic. Okay?

Barb C. :>)