We still dont know whether those samples contained XMRV or not but they concluded that the results were negative if this isn,t a fatal flaw i dont know what is.
Yes, the conclusion was also incorrect. And a good example of bad science.
We still dont know whether those samples contained XMRV or not but they concluded that the results were negative if this isn,t a fatal flaw i dont know what is.
Science does not include details of how the tests were done in original papers, these are available as supplementary information. My virologist friends feel that the details given in these by the WPI were very good and better than those seen in a lot of papers.
The reason for multiple samples is that XMRV does not replicate very often. It is only at those times the virus is replicating that it is free in the blood and able to be found by PCR. This means that only a sample taken at the right time will give a positive result unless you stimulate the cells in some way that encourages the virus to begin replication. Some patients needed blood taken at four separate times before the researchers caught the virus in the act of replicating.
When patients have been sending in blood to be tested XMRV is not being found in their blood unless it is actively replicating. If they culture the blood the virus gets coaxed into replicating so you get negative by PCR positive by culture.
Now they understand this they have stopped testing blood by PCR.
The WPI studies were done in more than one lab so they have already been replicated, that's why Mikovitz is confident that external replication will work if they follow the correct technique. This was a good, well done study, well planned and well executed.
The Kerr study was done quickly using things they already had to hand. They did not follow the WPI procedure because they did not want to do so. It wold have taken money and time to set up. There was no small deviation caused by a step left out of the Science paper, they made no attempt to follow the same procedure. This was not necessarily a bad thing, it might have worked but it was a decision they made, not something caused by sloppiness on the part of the WPI
They chose to use banked blood, probably also because of time and money constraints. Again it might have paid off but it didn't.
As for the Imp C study, school projects take longer to set up. This was rushed in the hope of putting a stop to research and the conclusions they reached were laughable if they were not so dangerous to us.
I stand by what I said. The Kerr study should have used a positive specimen of blood to test their procedure and only tested patients, banked blood or fresh, once they had perfected their technique. The fact that they didn't was a serious flaw.
I do not see why stating this means I am holding it up to a higher standard than the Mikovitz study. I am looking at both studies with a clear eye, I have a scientific background and virologists agree with me. It's time to let the WPI get on with their work for us.
Mithriel
XMRV: Examination of Viral Kinetics, Tissue Tropism, and Serological Markers of Infection
X Qiu1, P Swanson1, K-C Luk1, J Das Gupta2, N Onlamoon3, R Silverman2, F Villinger3, S Devare1, G Schochetman1, and John Hackett, Jr*1
1Abbott Diagnostics, Abbott Park, IL, US; 2Cleveland Clin, OH, US; and 3Yerkes Natl Primate Res Ctr, Emory Univ, Atlanta, GA, US
Background: Xenotropic Murine Leukemia Virus-related Retrovirus (XMRV) is a human retrovirus recently discovered in familial prostate cancer tissue using DNA array based Virochip technology. Understanding viral replication kinetics, tissue tropism, and the host immune response is fundamental to establish the etiology of XMRV infection in human disease. Development of serologic assays to detect XMRV-specific antibodies would facilitate epidemiologic studies.
Methods: Five rhesus macaques were inoculated intravenously with XMRV. Blood was collected throughout the course of infection, and tissue from multiple organs was harvested at necropsy. Two macaques were necropsied at day 6 or 7 and one at day 144 post infection. The remaining 2 animals were re-inoculated with XMRV on day 158 and necropsied on day 291. XMRV-specific immunoreactivity was monitored by Western blot using viral lysate. Recombinant env gp70, p15E and gag p30 were utilized to develop serologic assays on the high-throughput automated ARCHITECT instrument system (Abbott Diagnostics).
Results: XMRV inoculation resulted in low transient plasma viremia, although proviral DNA persisted in circulating peripheral blood mononuclear cells for several weeks. Of interest, the earliest leukocyte targets were CD4+ T cells and NK cells followed by CD8+ enriched T and CD20+ enriched B cells (50% positive); CD14+ monocytes were negative. Animals sacrificed at the acute stage showed evidence of viral replication in spleen, lung, lymph nodes and liver. In contrast, sacrifice of 2 animals at 19 weeks post XMRV re-inoculation showed greater dissemination of XMRV DNA and RNA in various organs including the GI and urinary tract as well as in vaginal tissue of the one female. By Western blot analysis, all 3 chronically infected macaques developed antibody responses to env and gag proteins. The serologic assays demonstrated 100% sensitivity by detecting all Western blot positive serial bleeds from the XMRV-infected macaques. Preliminary results showed evidence of detectable reactivity to all 3 antigens in a low proportion (~0.1%) of US blood donors.
Conclusions: These data suggest that lymphocytes are a primary target for replication persistence (low grade replication) of XMRV in the absence of detectable plasma viremia. This study identified specific serological markers useful for detection of antibodies induced by XMRV infection. The prototype antibody assays will facilitate large-scale epidemiological studies.
This was of course surprising to us given the prostate cancers were from Cleveland in different decades The contamination issue was settled in the original Science paper by the phylogenetic analysis and the immune response in the patients and the fact that XMRV was detected in samples sent to the NCI in Feb 2007 (before the WPI had a lab) ..these data satisfied the referees and were edited out of the final version of the manuscript as the editor as Science did not think it was important.
This person outlined a scenario of contamination either at the Cleveland Clinic or the WPI. The contaminant is not an endogenous retrovirus but XMRV itself permeating all the samples.
( I don't know how it doesn't get into the healthy controls).
I asked Dr. Mikovits about the high rate of genetic homogenity in the early samples - something that suggests the samples came from one source - which could only be a contaminant.
I think we should be prepared for anything; great news or bad news.
IMHO this isn't a realistic scenario. And surely it would have to be a contaminant at all 3 institutions at once (CC, WPI and NCI) since all the experiments were run independently at all 3 institutions?
I think you've destroyed the argument with that one observation.
I thought this issue has been dealt with. This is a very slow replicating virus. It is not that the WPI-isolated XMRV is homogeneous, its that all isolated XMRV is homogeneous (whether from prostate cancer, CFS etc.). If it was one contaminant you would expect the isolated viral sequences to be near identical, but there was enough difference in the genetic sequence to suggest we are not looking at a single contaminant, but a slow-replicating virus.
Also do we not think that someone like John Coffin, one of the greatest retrovirologists in the world hasn't thought of (and eliminated) this scenario?
A couple of weeks ago I might have agreed with you. But all the evidence seems to be pointing in the direction of XMRV being the cause of ME/CFS. The evidence also points to this being a difficult retrovirus to detect.
All this remains to be proven of course. But as I noted in the recent retroviorology conference, they still don't know how exactly HIV causes Aids, after all those billions of dollars, and decades of research.
A couple of weeks ago I might have agreed with you. But all the evidence seems to be pointing in the direction of XMRV being the cause of ME/CFS. The evidence also points to this being a difficult retrovirus to detect.
All this remains to be proven of course. But as was noted in the recent retroviorology conference, they still don't know how exactly HIV causes Aids, after all those billions of dollars, and decades of research.
I don't know. The 97% figure from the WPI has always made me worry something odd is going on with their results, and the two failed replication attempts haven't boosted confidence.
I'd have always been amazed if a single retrovirus caused all canadian definition CFS cases - but thought XMRV was likely to play a part in a significant sub-section of cases, and hopefully encourage more serious research for the rest. I really don't know - it's so up in the air at the moment that my thoughts are probably more emotionally driven than evidence based. The WPI's overwhelming confidence slightly unsettles me too - hopefully they know about a lot of successful replication studies we're unaware of rather than just getting carried away with their own work.
The symptom pattern for aids can be very similar neuroendocrine autonomic immunological malaise fatigue etc that is all caused by one virus one way or another
But the way CFS spreads seems pretty different. I say this as someone whose partner also has CFS - so I'm certainly open to it being a retrovirus, but it does seem strange.
Science does not include details of how the tests were done in original papers, these are available as supplementary information. My virologist friends feel that the details given in these by the WPI were very good and better than those seen in a lot of papers.
The reason for multiple samples is that XMRV does not replicate very often. It is only at those times the virus is replicating that it is free in the blood and able to be found by PCR. This means that only a sample taken at the right time will give a positive result unless you stimulate the cells in some way that encourages the virus to begin replication. Some patients needed blood taken at four separate times before the researchers caught the virus in the act of replicating.
When patients have been sending in blood to be tested XMRV is not being found in their blood unless it is actively replicating. If they culture the blood the virus gets coaxed into replicating so you get negative by PCR positive by culture.
Now they understand this they have stopped testing blood by PCR.
The WPI studies were done in more than one lab so they have already been replicated, that's why Mikovitz is confident that external replication will work if they follow the correct technique. This was a good, well done study, well planned and well executed.
The Kerr study was done quickly using things they already had to hand. They did not follow the WPI procedure because they did not want to do so. It wold have taken money and time to set up. There was no small deviation caused by a step left out of the Science paper, they made no attempt to follow the same procedure. This was not necessarily a bad thing, it might have worked but it was a decision they made, not something caused by sloppiness on the part of the WPI
They chose to use banked blood, probably also because of time and money constraints. Again it might have paid off but it didn't.
As for the Imp C study, school projects take longer to set up. This was rushed in the hope of putting a stop to research and the conclusions they reached were laughable if they were not so dangerous to us.
I stand by what I said. The Kerr study should have used a positive specimen of blood to test their procedure and only tested patients, banked blood or fresh, once they had perfected their technique. The fact that they didn't was a serious flaw.
I do not see why stating this means I am holding it up to a higher standard than the Mikovitz study. I am looking at both studies with a clear eye, I have a scientific background and virologists agree with me. It's time to let the WPI get on with their work for us.
Mithriel