Thanks Kurt...I didn't realize that. Have you heard of any other non xmrv pathogens giving false positives with this culture test? I guess the PCR tests solve that diagnostic problem anyhow.
The research literature has shown that false positives with that antibody study are common. So yes, there are other non-xmrv pathogens that will show positive with the MuLV antibody and culture tests used in the Science study. In my opinion that was an omission of the Science article, to not include references to that possible confound. This omission has contributed to an overly positive presentation of their study.
I see that everyone so far that is on this forum and that has taken the poll for Cooperative Diagnosis tested negative... Anybody finds this worrisome? That's now 10 of them...
Not worrisome at all, if you accept the many statements by WPI that XMRV could turn out to not be a factor in CFS. The problem is that many people (not all) have focused only on the idea that XMRV will be the cause of CFS and are ignoring the warnings, even those by WPI.
I remember when I first learned about Lyme Disease. I so hoped I had just Lyme Disease, and not CFS. So I got tested, got treated several different ways. Eventually I realized that people with Lyme had abilities that I did not, many can still exercise for example, and that I had CFS and not just Lyme. I guess that just shows how desperate we are for an explanation, and a solution. So for me, the CD poll means I should listen to WPI's warning, and realize that XMRV may not be what people had hoped.
The viral culture test is not an antibody test. The antibody test is not available yet.
What he means is that it "reads out" using antibodies. These are not patient antibodies, but rather ones stocked by the lab which are generally from rabbits, goats, whatever. They stick to XMRV and (in at least some cases) to related entities. They have a "fluorophore" attached which emits visible light when energized with UV light. So, if XMRV gets from the patient sample into the "bait" cells that are uninfected when the assays starts, you detect it by lighting it up using these brightly fluorescing antibodies.
You can make goat antibody against anything you want. All ya gotta do is jab it into a goat a few times appropriate intervals.
Exactly. And those antibodies are known to stick to a range of MuLV type infections and also HERVs.
Yep, it's concerning that if put side by side, the CD and VIP labs are turning out very different results. The implications beyond just the obvious seem worthy of inquiry.
CD and VIP are not that far apart, considering how early we are still in the science. VIP seems to be having many fewer positives than the statistics from the WPI study would indicate. And which direction are they actually heading? The positives seem to not be increasing as fast as the negatives.
http://www.midlandsbiz.com/articles/4289/
Well, there have to be at least 2 XMRV positives using the test, right? What about the 2 friends with CFS that inspired Brent C. Satterfield, Ph.D., President and Founder of Cooperative Diagnostics, LLC. to come up with the XMRV test in 16 days. He did check it on them. Didn't he? Kurt?
Makes me wonder about the possibility of all the macho guys in Guatamala bragging to the senoritas that they are HIV negative:
CD has a 100% reliability on their XMRV test. Dr Satterfield is a biomedical engineer, he helped the Dept of Homeland Security with anthrax testing, and he has developed tests for many govt agencies, including internationally. CD specializes in rapid test development, they could do that already before XMRV. The level of incompetence you are assuming just does not fly with the facts here. Of course there is a chance the CD test is totally inaccurate, but I think the odds are very small. An alternate scenario is that there was a problem with the WPI PCR study, and their antibody and culture tests hit on the high level of HERVs in PWC rather than on XMRV. Also, the samples they sequenced might have been real positives from lymphoma patients, after all that is how they found XMRV, by studying CFS Lymphoma samples.
So it is possible the CD results do not show XMRV because it simply is not there very often. If XMRV were there they would probably find it, as they do in known positive prostate cancer samples (they can find a single antigen cell in a small sample, that is as good as it gets). Some replication studies are finding the same thing, no XMRV in PWC. This scenario has happened before, in retroviral hunts in other diseases. I think WPI knew that, and so they tried to warn us, but at the same time they needed support for their new center, so they have been walking a fine line. I hope they resolve this soon, they have to realize by now something is wrong. They are in a double bind. If replication studies are failing because WPI did not explain completely how they run their tests then they will look bad and researchers will not trust them. On the other hand if the replication studies are failing because XMRV is simply not there, they will look over-eager, like they published too soon. I think the second scenario is better for WPI, and understandable for a new research group in a difficult economy, so I hope that XMRV is actually not there and this is just an artifact of the scientific method. Then we can see what else WPI has to offer, such as explaining the interesting findings of their virachip study. Anyway, time will tell all...