CAA - WPI only lab reporting false positive result. (Is this correct?)

[V99]

Too right, arrrrrrrrrg woof. Bring on the next stage. Sorry, I'm not explaining well, and I'm not sure if I am confused, but I suspect I am.

 

[George]

Too right, arrrrrrrrrg woof. Bring on the next stage. Sorry, I'm not explaining well, and I'm not sure if I am confused, but I suspect I am.

You are on this one issue. Trust me both the WPI and FDA got it wrong. You are right that the CAA needs to make the corroection though and that's what this thread is about right ?! (grins)

 

[V99]

woof woof

 

[omerbasket]

Got it! Think about it like this (If I over simplified, I'm sorry). . .

I'm a science teacher teaching my class to calibrate a weight scale, so they can tell me how many drops of water are in each of say 6 tubes.
I give each group of kids (NCI, CDC, WPI, FDA, NIH etc) in the class
1 empty tube
1 with 1 drop of water
1 with 2 drops
1 with 3 drops
1 with 4 drops
1 with 5 drops of water.
But the kids can's see into the tubes they are opaque and sealed. Everybody get the same sets. The group that get's each tubes water amount correct wins the big prize. An A. (grins)

Each kid has to figure out how to set the scale so that the empty tube is the base line (0 XMRV) and then be able to weigh each tube and say exactly how much water is in each tube. (1, 2, 3, 4, or 5 drops or in this case how many copies of XMRV)

All of the groups NCI, CDC, FDA, NIH got exactly the same tubes with the same amounts of XMRV in them. One had 0 ( I can't really make out the numbers but say for argument ) one had 20 copies of XMRV, one had 100 copies, 500, 1,000 and 5,000. Each team used the serology assay that they had come up with to see if they could determine how many copies where in each tube. They wrote down their answers and handed them in.
This chart is the result. If you got a red bar then you were dead on the money, if you got a yellow bar you were half right, (partial credit here) if you got a green bar you where wrong. Both the FDA and WPI got one wrong answer each.

What does that mean? Well, the WPI are still the smart kids in the class in that, even though their serology test wasn't perfect they are still the best at finding XMRV the old fashion way using the culture methods. They are still best at checking their work. Most likely the reason VIP hasn't put the serology test up yet is because the WPI had to fix the problem with their test. I have no doubt that they would not put out a faulty test. Once they figured out what the problem was they went back and fixed it. Which is why it's 6 weeks late from the original release date.

And so what, the CDC (the smarmy little kid in the back of the room, grins) got it right this time around. I don't think the CDC wants to be left out of XMRV research, too much money coming down that pike, they just don't want to find it in CFS. (grins) But I have to say thanks for whipping up an accurate serology test.

Not to worry because all of these groups will patent their revised tests and market them.

I don't understand if you said "serology test" just for the joke (because of the delay in the serology test of VIP Dx.), or if you really thought it was a serology test that the WPI did in this blood panel - but to be sure, I will clarify again that it wasn't serology, it was qPCR.

 

[George]

I don't understand if you said "serology test" just for the joke (because of the delay in the serology test of VIP Dx.), or if you really thought it was a serology test that the WPI did in this blood panel - but to be sure, I will clarify again that it wasn't serology, it was qPCR.

No I did not say it for a joke. Omer, I realize that you have an e-mail from Dr. Mikovits and that makes you the last word and authority on this subject however, I would like to point out that what you don't have is the actual information about the study itself. Neither do I.

Analytical panels of blinded samples of XMRV and negative controls were tested by six laboratories (including the Whittemore Peterson Institute) to assess results using different methods. All six laboratories were able to detect XMRV in whole blood using nucleic acid testing and four of five plasma RNA assays performed well. CDC's whole blood assay was the most sensitive under these conditions, while WPI was the only lab reporting an unexplained false positive result on a negative sample.

This was a titer test. They wanted to know if they could detect titers or viral loads. Now I could be wrong but you don't check titers with a qPCR test. I think we may both be missing information here.

 

[jspotila]

As updated today, the CFIDS Association page on XMRV includes this statement about the FDA analytical panel results, "The Phase 1 study has its limitations and these results should not be extended to other published data."

The Association did not state or intend to imply that the panel results (including the one unexplained false positive from WPI) had any bearing on the data in the Science paper. This is a misconception about the significance of the panel results. As I said earlier, there will be a summary of the meeting in this week's CFIDSLink, and the FDA is planning to post the presentations to its website in the near future.

 

[Dr. Yes]

Hi George,

The way I understood it was that they took blood that was "known" to be negative, spiked with this "cloned copy" (so that everybody had the same chance of finding or not finding it) the spikes where different strengths to test "titer" type levels. They sent these kits to each lab and let each lab test their "serology" test on the kit samples.

Actually, it appears from the table (if it does indeed say "copies" on the y-axis) and from Dr. Mikovits' email that the results in the table are for qPCR only; they are the results of assays for viral load via PCR, in copies of virus per unit blood. Each lab had to test their assay sensitivity with whole blood and plasma spiked with varying concentrations of plasmid (synthetic XMRV clone), using supposedly "negative" controls.

What I don't understand is how they determined that those control blood samples contained no naturally occurring XMRV in the first place. That's why I'm not certain those false positives are necessarily 'false'.

All of the groups NCI, CDC, FDA, NIH got exactly the same tubes with the same amounts of XMRV in them. One had 0 ( I can't really make out the numbers but say for argument ) one had 20 copies of XMRV, one had 100 copies, 500, 1,000 and 5,000. Each team used the serology assay that they had come up with to see if they could determine how many copies where in each tube.

Copy numbers are used in PCR and other nucleic acid assays, not serological assays. Mikovits further confirmed that the test in question here was a qPCR test.

What does that mean? Well, the WPI are still the smart kids in the class in that, even though their serology test wasn't perfect they are still the best at finding XMRV the old fashion way using the culture methods. They are still best at checking their work. Most likely the reason VIP hasn't put the serology test up yet is because the WPI had to fix the problem with their test. I have no doubt that they would not put out a faulty test. Once they figured out what the problem was they went back and fixed it. Which is why it's 6 weeks late from the original release date.

Again, this was not a serology test. The VIP's serology test is an antibody test that has nothing to do with the nucleic acid assays used in the blurry table we are all staring at. Thus there is no evidence here that there is anything wrong with the VIP's serology test.

It's impossible for the sample to be positive.

As I mentioned previously, we don't know that until we know more about the processes by which they determined the samples to be XMRV negative, and I don't see how one could do that with absolute certainty, lacking fool-proof assays in the first place.

This was a titer test. They wanted to know if they could detect titers or viral loads. Now I could be wrong but you don't check titers with a qPCR test. I think we may both be missing information here.

Again, from everything we know at this point, this particular table appears to represent qPCR test results.

 

[George]

Well, there ya go I'm totally out behind the bushes on this one. Huh, I guess nobody thought to test the blood for XMRV.

 

[omerbasket]

No I did not say it for a joke. Omer, I realize that you have an e-mail from Dr. Mikovits and that makes you the last word and authority on this subject however, I would like to point out that what you don't have is the actual information about the study itself. Neither do I.



This was a titer test. They wanted to know if they could detect titers or viral loads. Now I could be wrong but you don't check titers with a qPCR test. I think we may both be missing information here.

George, as Dr. Yes said - this table should represent qPCR. I'm not a scientist so therefore I don't know if you are right when what you say about not checking titers with qPCR, but you have talked about them wanting to know if they can detect viral loads. Now, since qPCR represents quantitive PCR, then I guess this test is performed in order to detect viral loads...
Anyway. Dr. Mikovits said that this was qPCR, and I don't see a reason to doubt it.

Edit: Now I read the whole message of Dr. Yes, and he really said it all with much more scientific knowledge than me... and I also saw that you now agree with us, George :Retro smile: