Transcription part 2
...continued directly from previous post - no gap in the transcription...
Subject: CFS, XMRV and the Science Paper
from 27 mins 55 secs
Interviewer:
So last year ... the Science paper came out, showing a strong association of XMRV with patients with Chronic Fatigue, and you were already at Utah at the time, so I assume that you, on hearing that, you decided to look into that as well?
Dr Singh:
Yes, we did. So that is another ongoing project.
What we are doing is we are looking at 100 patients with Chronic Fatigue Syndrome.
We collected fresh samples from them.
And we collected samples from 200 healthy volunteers.
All of these people live in and around Salt Lake City.
We are analysing and looking for XMRV using a battery of different tests...
So, using multiple PCR tests that look at different parts of the genome.
Doing RTPCR, looking for the virus, looking for the viral RNA.
And we are using some of the same tests that the paper in Science reported.
Namely the one where you take human plasma and you add it to LNCaP cells.
LNCaP cells are a prostate cancer cell line that are particularly good at growing XMRV.
And then you culture these cells for a while and then you keep looking for evidence of XMRV infection in these cells by various means.
So it's a whole bunch of tests.
We are also doing some serological tests that we have developed.
So we'll see what we find...
Interviewer:
Are these different patients from the Science study?
Dr Singh:
Yes, they are completely different patients from the Science study.
Interviewer:
Now, how are you defining your CFS cases? Because that's been a bone of contention too, I gather.
Dr Singh:
Yeah, it's really hard. We have different criteria that we have used... Fukuda criteria etc.
And then the physicians have categorised them into different severity groups.
And we have people from very severe, moderately severe and the most functional group.
But these are very hard things to categorise, so one of the physicians who is involved in the study was explaining to us that sometimes you can call somebody very functional because they are holding a job, but the nature of the disease is such that if they stress themselves out more, then they are likely to get more sick. So sometimes, by our sort of measure, ways that we measure function, we'll say that this person is really functional, they actually hold a full time job. But the real fact maybe is that's all they do... is that they go to work, they work, and then they come back, then they are unable to do anything else. So these are very difficult categorisations, and it's a hard disease to just, you know, put a number on it, or put something quantitative, that'll help us. So we're struggling, as is everyone else, to make some sense out of these.
Interviewer:
What is the best material to use; so, the original paper used blood or [inaudible]... So are you doing the same, or are you doing more than that. We don't know where the virus is, right?
Dr Singh:
That's exactly right, so we have no idea where the virus is. So we're just doing everything that we can... so we are looking at white cells in the blood, we're looking at plasma, we're looking at serum for antibodies, we're looking at... we have a whole blood assay that we're using. So, basically, every fraction of peripheral blood that we can look at.
Interviewer:
Which is the easiest sample to get, I suppose?
Dr Singh:
It's the easiest sample to get from these patients.
And really, for chronic fatigue syndrome, it's hard to know what else might be the best tissue.
For prostate cancer it's obvious, right, you just use the prostate cell...
Interviewer:
It could be, for CFS, it's a different tissue, right?
Dr Singh:
Yeah, it could be the brain for example... I mean, who knows, right?
Interviewer:
So, here again, my understanding is that there's been a lot of conflicting evidence, or controversy, in the literature about an association between CFS and XMRV which, again, could be the assays.
What i've been looking for is for the individuals involved to swap samples. Has there been any of that?
Dr Singh:
Yes, so, I can only tell you about what we are doing... and so, Judy Mikovits, who is the main author of the original study that showed that XMRV was present in chronic fatigue syndrome, has been kind enough to make arrangements to give us samples... adn we are sort of mid-way in getting samples from her. And this is how it's happening... she gives us the names of people who are positive for XMRV in their hands, and people who are negative for XMRV in their hands, to a phlebotomy service. The phlebotomy service then goes to these patients and collects the samples and then they directly send the samples to us. So there's no question that the sample may get contaminated, somehow, in the Mikovits lab, which has XMRV growing there... so it's coning straight from the patient to us.
Interviewer:
And are these samples coded when they get to you?
Dr Singh:
They are all coded, so we're completely blinded. We won't know which one is positive, which one is negative.
Interviewer:
Perfect.
Dr Singh:
So we have so far, i think, gotten about 9 samples, and we'll probably get an equal number more, and then we'll start the analysis on those. So that is an ongoing process.
Interviewer:
Excellent. I look forward to seeing that.
Interviewer 2:
I presume that this and many other studies are gong to be needed before we really have a sense of where [or when?] the virus is replicating, how it causes disease, and if it is associated with disease. Is that a reasonable statement to make?
Dr Singh:
That's an absolutely reasonable statement to make, yes.
Interviewer:
Because, from what i see, this is a growing field now. XMRV has had a meeting at Cold Spring Harbor, there's a meeting at NIH in September. So it's a brand new field.
And probably you never thought that a Murine virus would be clinically relevant? all those years...
Dr Singh:
That's right.
35 mins 27 secs
Interviewer:
Now, you published a paper showing that XMRV is susceptible to some HIV anti-virals
Dr Singh:
That's right, yes.
So it is susceptible, probably, most susceptible to a drug that inhibits HIV integrase called Raltegravir.
And it is also susceptible to a couple of drugs that inhibit the reverse transcriptase enzyme, so...
AZT which is the well known anti-HIV drug.
And then Tenofovir Disoproxil Fumarate, or TDF, which is the pro-drug form of Tenofovir which inhibits RT.
So those are particularly effective at inhibiting XMRV in cell culture.
We haven't done any animal or human studies.
Interviewer:
So this is an interesting situation, because they're approved, obviously for treating AIDS, and they can be used off-label, for example an XMRV-positive patient could go to their physician and say "I want to have this". And, so what would need to be done to have FDA approval for the use of these in, say, treating XMRV infection?
36 mins 47 secs
Dr Singh:
We are talking, right now, with Merck to start a clinical trial, which would be double blind, placebo controlled, clinical trial in chronic fatigue syndrome patients.
And the reason to do that was that it was brought to my attention that a lot of patients were already taking these drugs, and were blogging about it on the web.
So it just seemed wrong to not actually try to find out by scientific means if these drugs were effective or not.
So we are in the very early stages of talking... it may not materialize in the form of a clinical trial, but that's what we are engaged in.
Interviewer:
I guess it's early in the story, and so it's hard to generate the information you need to do such a trial, because, again, we don't know where the virus is replicating and how it is pathogenic...
Dr Singh:
That's right... And it's hard to even measure... how will you measure the outcome of your trial?
Interviewer:
Right, especially since CFS, in particular, is, in many patients, a relapsing/remitting sort of condition...
Dr Singh:
That's absolutely right...
Interviewer:
Anything you give these people may appear to work in some of them.
Dr Singh:
Right.
Interviewer:
So the trial you describe would be to see if individuals with chronic fatigue have symptoms that are ameliorated in any way by treatment?
Dr Singh:
Well, it's not known yet how we would do it, but we are just in the process of just talking. Ideally it would be great if we had a lab [?] test that we could look at... if we could measure viral loads before and after...
Interviewer:
Yes, that's a good point, because without that, it's hard to measure the efficacy of the treatment, right?
Dr Singh:
If it's going to be hard to measure the virus in disease, then it's a hard thing to....
Interviewer:
The other approach is, of course, for testing, say, an HIV drug... You give it to a susceptible population and then you see the fraction that are protected by it. Or a vaccine, even. But that can't really be done at this point with XMRV, I presume.
Interviewer 2:
And even in the AIDS trials, I'm sure they measure viral load, and stuff, right, so...
Interviewer:
And you also have the confounding factor that those patients have HIV.
Dr Singh:
Yes, and also in the AIDS trials, viral load came up much later and some of their early studies were just done on symptoms and T-cell counts, and much more cruder assays than viral.
Interviewer:
Assays run by pathologists, right. [laughs]
That's a good point... early on we didn't understand much about viral loads... that's a good point.
Interviewer 2:
Well my guess is that you're not going to have any trouble getting people to enroll on this study. Sound like the people who are afflicted by this are really desperate for some sort of treatment.
Dr Singh:
Yes, i sense that desperation when i see the blogs and when people write to me all the time.
But, really, it's too early in the game for people to be, erm, you know, to even know what this virus is doing.
Interviewer:
Yeah, and i think that when people are talking about taking anti-retrovirals, these are not benign compounds... It's a mighty big gun to aim at a target that we can't even identify yet.
Dr Singh:
That is correct; These drugs are not without their side effects.
Interviewer:
Do you know how common CFS is in this country? What sort of numbers of patients we are talking about?
Dr Singh:
Yeah, people throw around different numbers, depending on what study they quote. Something like 0.5 to 2%... these are huge numbers. A lot of patients...
Interviewer:
I was just thinking that when AIDS first surfaced in the 1980's... i just wonder if patients... i suspect not... i have a fuzzy memory... maybe you remember, Ila, better... but was there the same type of patient response, or was it such an unusual and rare disease initially, that, you know, you didn't have people saying "i think i have this; treat me"...
Do you know what i'm talking about? Do you recall the atmosphere at the time?
Dr Singh:
erm, no, actually i don't...
Interviewer:
I'm just wondering if this is a new phenomenon where, from this point forward now... a new disease, or a disease that hasn't been sorted out... as soon as there is some suggestion of an infectious agent, there'll be clamouring for very very quick solutions, and, as you know, they never come quickly.
Dr Singh:
That's right... I also think that there are two things going on... There's the desire in the Chronic Fatigue Syndrome patient group to be cured, of course, which is common with the poeple who had HIV... but, in contrast, people with HIV... people took their disease seriously from day one... they knew that they had a disease, whereas here, there are many people who are not even sure if chronic fatigue syndrome is an entity... So having a clear test, like, you know, showing that there is a virus, that is specific to this illness would mean more than just treatment... it would also validate, for these patients, that they have a real disease. OK, so there is that going on also in this.
43 mins 15 secs
Interviewer:
One of the things that came up with the XMRV-CFS link, and obviously that's still all up in the air, but already we've already had discussions that CFS patients shouldn't give blood. Is that an appropriate precautionary reaction, or is that premature?
Dr Singh:
Well, it's probably an appropriate precautionary reaction. There are several countries that have already asked people, with CFS, not to donate. Australia, Canada have already done that. Considering that there are not that many CFS people who are going out to donate, it is not probably not a huge risk, but it would probably not be a bad precaution to have until we know a little bit more about the disease.
44 mins 12 secs
