She believes XMRV isn't in ME/CFS patients but that there's evidence for the retrovirus in prostate cancer
CFS Central emailed University of Utah's Dr. Ila Singh about her new XMRV study, which found no evidence of XMRV in ME/CFS patients. In 2009, Singh found evidence of the retrovirus in prostate-cancer tissue.
CFS Central: Will you revisit your prostate-cancer XMRV findings in light of this XMRV negative CFS study? From what you’ve learned in this latest CFS study, do you now believe that the XMRV that you found in prostate cancer is a human infection or just contamination?
Dr. Ila Singh: Prostate cancer and chronic fatigue syndrome are completely different illnesses. I recognize that recent studies have cast doubts on the prostate cancer association as well, but there is still considerable data supporting the link to prostate cancer that cannot be easily explained by contamination. We will present some of this work at the Cold Spring Harbor meeting later this month. But clearly more work needs to be done before that question can be settled.
CFS Central: Do you believe scientists should be looking for XMRV in CFS patients’ tissues instead of blood?
Singh: The original study by Mikovits' group reported finding XMRV only from blood. They did not examine other tissues. So blood is where the focus should be. Now if one found it in blood, then of course you'd be interested in finding out where else the virus is. And then it would be interesting to look at tissues. But looking at tissues is not trivial and not something to be attempted without good evidence of the virus being present in the body first.
CFS Central: Did you test the new assays/methods used in the new study against any XMRV positive samples from your prostate-cancer study?
Singh: Our prostate cancer study was entirely on prostate tissues. These were archived in tissue banks in a de-identified manner, so there was no way to go back to those patients and obtain blood samples. So, we could not test some of the new tests we developed on our material from prostate cancer patients.
CFS Central: In your new study it says that “2 positive controls were also included” (line 349 of your study). Were the two positive controls clones or clinical samples from prostate-cancer studies or from Mikovits’s positive CFS patients?
Singh: The samples from Mikovits' patients were all tested in a completely blinded fashion. We did not know which of them were positive, so could not use them as positive controls. But more accurately, there are no real patient 'positive controls' for XMRV. In order to use patient samples as controls, you'd have to first be absolutely certain that these patients have XMRV. How could you do that right now? So we used what you call a 'clone' for our PCR studies. But remember, this clone was isolated from a patient (a prostate cancer patient). And this is over 99% identical to the isolates from CFS patients described in Lombardi et al. For the viral culture studies, we used very small amounts of titrated virus that was grown in the lab as positive controls. And all of these positive controls were always positive.
CFS Central: You grew XMRV in the prostate-cancer cell line LNCaP and the breast-cancer cell line MCF-7 in your study “Raltegravir is a potent inhibitor of XMRV, a virus implicated in prostate cancer and chronic fatigue syndrome.” It’s unclear to me why the new study didn’t culture XMRV from those two positives.
Singh: Yes, we did. And these grew just fine. Apologies for not being clearer in the paper. None of the patient samples tested positive, but the positive controls were always positive.
CFS Central: Some patients on the forums find this sentence from the new study problematic: “We are forced to conclude that prescribing antiretroviral agents to CFS patients is insufficiently justified and potentially dangerous.” The Science and the Alter/Lo studies have reported XMRV and related MLVs in CFS patients. CFS patients are very ill, many for decades, and there are no approved treatments. They believe the decision to try antiretroviral drugs should be between a patient and his or her doctor. Why did you feel the need to put that statement in the study and press release?
Singh: The patient and their doctor did not make the decision to try antiretroviral drugs in a vacuum. It was based on reports of finding XMRV in CFS patients. We are now convinced that there is no XMRV in CFS patients--so the reason for starting those drugs does not exist. And there is no good evidence for continuing to use drugs that could lead to serious side effects of liver or bone-marrow failure.
****
I wrote to Singh to ask her to clarify two of her answers:
CFS Central: In your prostate-cancer study, “XMRV is present in malignant prostatic epithelium and is associated with prostate cancer, especially high-grade tumors,” you found 4 percent of healthy controls with evidence of XMRV. If you’re finding a background rate in controls in your prostate-cancer studies, why do you think you didn’t find a background rate in CFS patients and controls?
CFS Central: To clarify one of my previous questions, beginning on line 347 of your new study, it states: “We inoculated LNCaP cells with 100 [microliters] of plasma from 31 patients and 34 healthy volunteers, and passaged the cells weekly for 6 weeks. 13 negative controls and 2 positive controls were also included. Only one culture was handled at a time to prevent any cross-contamination. After weeks 2, 4 and 6, cultures were lysed and analyzed by Western blots (Fig. 4) and by qPCR for XMRV. No XMRV protein or DNA was detected in any of the cultures. [emphasis added]
My question is this: Is the bolded sentence correct, or did the 2 positive controls grow in these cultures and/or did the positive samples continue to test positive in culture? If the positive controls didn’t grow or if the positives controls didn’t test positive in culture, why didn’t they? You grew XMRV in the prostate-cancer cell line LNCaP and the breast-cancer cell line MCF-7 in your study “Raltegravir is a potent inhibitor of XMRV, a virus implicated in prostate cancer and chronic fatigue syndrome.”
Singh: That was our poor wording in the paper (the words in bold). All positive controls grew XMRV--as one would expect. None of the samples from the healthy controls or CFS patients grew any virus in culture. And of course the negative controls did not grow any XMRV.
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How convenient of Dr. Singh to "correct" the wording of the published study.
ReplyDeleteMy thoughts are 1) was Ila Singh threatened for XMRV research and coerced into publishing this or 2) is she financially motivated to publish a negative study.
Given she has a patent for treating XMRV/MLV illnesses along with another scientist closely tied to pharmaceutical companies, financial motivation is present.
The future will reveal the truth. I'm sad Dr. Singh appears to have succumbed to political or financial pressures.
Thank you, Mindy. I am so glad you were able to get Dr. Singh to answer some questions.
ReplyDeletePatricia Carter
great interview, Mindy.
ReplyDeleteShe is convinced she has proved with a novel assay and non replication study that XMRV is not in ME.
ReplyDeleteShe is convinced it is an infectious RV in prostate cancer.
Yet she is "not sure" why she didn't detect background levels of at least 4% in the ME study like she detected 4% in healthy controls in her prostate study.
Any objective scientist would tell her it was because her assay, methods and calibration were flawed and inadequate.
Funny how Lipkin is saying so on the Rancanellio blog more or less by saying that there is no evidence of contamination in positive studies.
Here are Lipkins exact words;
"Dear Vince-
We have a plethora of explanations for how CFS/XMRV/MLV studies could go awry. However, we don’t have evidence that they have. Absent an appropriately powered study representing blinded analyses by Mikovitz and Lo/Alter of samples from well characterized subjects using their reagents, protocols and people, all we have is more confusion.
I remain agnostic. We won’t have answers until the end of 2011.
The NIH will post something on our study today".
Thankyou Mindy for asking such critical questions.
Thank you Mindy. I am glad you asked some of these questions, especially the one about the 4% background rate.
ReplyDelete"Singh: Not entirely sure, but there were different assays (e.g. immunohistochemistry) and different sample types (blood vs prostate tissue)."
This answer is just bizarre. Singh is absolutely sure none of the 300 people she tested are infected with XMRV, and it's apparently contamination. Then she goes and says that, well she isn't sure, maybe she didn't detect the background rate because the assay was different, and the sample type was different. That's some contradiction.
To the people attacking Singh, this is crazy. She is a highly accomplished researcher with all the right intentions. She has been studying XMRV for years and in previous interviews seemed very excited about the possibility of finding XMRV in CFS patients.
ReplyDeleteTo attack her does nothing but make the CFS community look like a bunch of crazies and push away the people we need the most, the researchers.
Mindy, I have a question regarding this statement by Dr. Singh: "Not entirely sure, but there were different assays (e.g. immunohistochemistry) and different sample types (blood vs prostate tissue)."
ReplyDeleteWhy didn't she use the same immunohistochemistry type assay on the CFS/XMRV samples that she did on the prostate samples? Is it an assay that can only be used on tissue and does not work for blood samples? I don't understand why she wouldn't use the same assay.
Thanks, I didn't realize Dr. Singh had found the 4% background rate in controls in her prostate studies, too. That fits in well with the 4% background rate that the Mikovits study found in blood. I would feel a lot better if Dr. Singh had found the same rate in her present study.
ReplyDeleteI also was looking forward to seeing her immunohistochemistry results as compared to the other methods. She went to lengths to explain why it was less contamination prone, easier to spot XMRV, etc, and why she was going to use it in this study. I'm surprised to see it not there.
I found this to be the best question:
ReplyDeleteCFS Central: In your prostate-cancer study, “XMRV is present in malignant prostatic epithelium and is associated with prostate cancer, especially high-grade tumors,” you found 4 percent of healthy controls with evidence of XMRV. If you’re finding a background rate in controls in your prostate-cancer studies, why do you think you didn’t find a background rate in CFS patients and controls?
Singh: Not entirely sure, but there were different assays (e.g. immunohistochemistry) and different sample types (blood vs prostate tissue).
Oh, by the way, I thank Dr. Singh for taking on this study of XMRV in ME/CFS. I think she is a top notch scientist.
ReplyDeleteDear Mindy,
ReplyDeleteThe incisive quality of your investigative reporting once again highlights the lazy and inadequate efforts of mainstream newspaper health journalists.
In your discussion with Dr. Singh, you asked some crucially searching questions, to which she gave unconvincing answers.
Thankyou and well done again.
Mindy, thanks for continuing to cover the CFS story and thanks also to Dr Singh, who is a highly reputable CFS researcher who has been working hard to get to the truth about our illness. I know that we are all desperate to find the cause for our disease but to accuse Dr Singh of not acting in good faith is ridiculous.
ReplyDeleteI often see comments on articles like this attacking scientists whose results aren't favoured and I think that these responses come from deep distress. But I do not think that they are representative of the majority of patients who just want to get well and are grateful to scientists who take our illness very seriously and want to get to the bottom of it.
We must not drive good scientists away from us. XMRV has got us a lot of attention from scientists and we must encourage them to keep trying to help us, whether or not XMRV pans out.
Isn't it "funny" how there is one "person" who is very determined to paint the ME/CFS community as "crazies" every chance they get and on many blogs and forum comments sections? One could almost think there is an agenda. But then again I'm probably just being crazy. Oldest trick in the book.
ReplyDeleteI'm sorry, but if Dr. Singh can't satisfactorally answer the very basic question to do with the 4% background rate, then this study is unsound and means nothing much at all.
ReplyDeleteThanks, Mindy, for asking these important questions. I think it's premature to claim that "XMRV not associated with CFS, comprehensive study finds" as her press release does. This is the take-home message everyone reading any news of this will get and it's overreaching. We don't know yet for sure for the reasons other commentors here have noted.
ReplyDeleteGreat Interview Mindy!
ReplyDeleteI have to say this study has a lot of holes in it:
-Singh found it at a background rate of 4% in controls in her prostate studies, yet found it at 0% here (suggesting her assays don't work).
-Singh says "blood is where the focus should be", yet we know that this virus is extremely difficult to find in blood, that it only stays there for a short while before mostly disseminating to tissues. Singh can find it in Prostate Cancer tissues without difficulty, yet she refuses to test ME/CFS patients tissues because she says "But looking at tissues is not trivial and not something to be attempted without good evidence of the virus being present in the body first." Yet at least one ME/CFS doctor is routinely sending his patients for stomach biopsies and finding XMRV there!! So the doctors can find it but not the researchers???
-Singh cannot test her blood assays on her positive prostate cancer patients since "Our prostate cancer study was entirely on prostate tissues. These were archived in tissue banks in a de-identified manner, so there was no way to go back to those patients and obtain blood samples". So there is no way of knowing if her assays even work!
-They used "artificial" positive controls: "For the viral culture studies, we used very small amounts of titrated virus that was grown in the lab as positive controls." Finding XMRV in artificial controls is much much easier than finding it from actual blood samples, so again this tells us nothing about whether her assays can detect it from an actual patient sample.
All in all very disappointed with this study and the misplaced confidence Ila Singh apparently has in her results (by making treatment recommendations to patients).
I have one question for Dr. Singh. She can find XMRV in prostatecancer patients. Can she detect XMRV in the blood by these cancer patients? I ask this because she don't tested CVS patients in the tissue.
ReplyDeleteFantastic questions Mindy. It seems that there're even more unknowns and things to clarify in this study than we previously thought.
ReplyDeleteWhat a shame.
ReplyDelete"Singh: Our prostate cancer study was entirely on prostate tissues. These were archived in tissue banks in a de-identified manner, so there was no way to go back to those patients and obtain blood samples. So, we could not test some of the new tests we developed on our material from prostate cancer patients."
Perhaps Singh could source blinded prostate (and breast) cancer tissue and blood and repeat the work. That may help to validate/invalidate her blood assays.
Highly accomplished researchers can miss the mark. It's not a knock on Sighn to say it's posible her assays don't work.
ReplyDeleteAgain until we have multiple repication studies HGRV research in ME still remains an area of confusion at best.
What needs to be done is a nmber of exact replications. Then if the same results are found the experiment needs to be done again and again changing only one variable each time it is performed to figure out which variable matters in the results and why.
Singh's primate study found that XMRV left the blood of the infected primates after a few weeks (6, I believe). Isn't that finding plus the finding of XMRV in prostate cancer patient tissue good enough evidence to justify a study looking for XMRV/MLV in the tissues of patients with ME/CFS?
ReplyDeleteQuote:
CFS Central: Do you believe scientists should be looking for XMRV in CFS patients’ tissues instead of blood?
Singh: The original study by Mikovits' group reported finding XMRV only from blood. They did not examine other tissues. So blood is where the focus should be. Now if one found it in blood, then of course you'd be interested in finding out where else the virus is. And then it would be interesting to look at tissues. But looking at tissues is not trivial and not something to be attempted without good evidence of the virus being present in the body first. Unquote.
Singh: "We are now convinced that there is no XMRV in CFS patients--so the reason for starting those drugs does not exist."
ReplyDeleteOne study would not definitively disprove the original findings.
This would be imply that Science and PNAS were duped into publishing the WPI studies?
Unless it is again the definitional issue, which is why CFS should be abandoned (not only the name).
Thanks to Mindy for asking the questions and to Dr. Singh for answering them.
ReplyDeleteLipkin seems a real scientist.
ReplyDelete"We have a plethora of explanations for how CFS/XMRV/MLV studies could go awry. However, we don’t have evidence that they have. Absent an appropriately powered study representing blinded analyses by Mikovitz and Lo/Alter of samples from well characterized subjects using their reagents, protocols and people, all we have is more confusion."
http://www.virology.ws/2011/05/06/ian-lipkin-on-xmrv/?utm_source=feedburner&utm_medium=email&utm_campaign=Feed%3A+VirologyBlog+(virology+blog)
"To the people attacking Singh, this is crazy."
ReplyDeleteI agree. It's also incredibly hypocritical, as most of those attacking her, were praising her up until this negative study came out.
These attacks are also an insult to the Lights, who have a friend who DIED from CFS/ME.
Sheesh.
I don't believe that respectful questions, expressions of doubt, or requests for clarification constitute any sort of attack on Dr. Singh. In a spirit of respectful inquiry then, I do want to know what would explain detection of antibodies to XMRV via serology, in a "CFS" diagnosed patient like my 17-year-old. In a recent exchange on Twitter, Dr. Racaniello suggested that what were detected could be antibodies to a very similar virus but not XMRV. In that case, shouldn't that virus be looked for and examined? My kid has antibodies to *something* and is terribly ill. The same goes for many patients who got positive results from the same test.
ReplyDeletePlus I've been wondering about that 4%, as well.
Thanks for the great work once again, Mindy!
~ Kassy
Thank you Mindy for asking the right questions.
ReplyDeleteHIV was only discovered when Dr Luc Montagnier found a virus in a Lymph node biopsy of a patient.
Researchers from different countries had been looking in the blood of patients with no success. It took time to develop the rights tests.
It's not unreasonable to assume that different techniques return different results.
Dr Singh did not use a test proven to find XMRV in the blood of any human patient.
She was unable to find XMRV in the blood of any controls.
As this jars with her prostate cancer tissue results (where she found XMRV in controls) it's reasonable to assume that problem is with her methods.
A control is a control. XMRV is a human retrovirus and the argument is not over that. It's in the human population.
The argument is over who has it and how to find it. Dr Singh hasn't developed a reliable method of detecting the virus in blood yet. This paper reflects that failure.
I am rather perturbed at the number of times various people are writing-off XMRV as being in association with ME/CFS, when none of the experimental data suggests such a positive conclusion. The titles of the articles go beyond the deductions possible from the experiments. To me, this is a bit sinister, as in "methinks the lady doth protest too much".
ReplyDeleteSeriously, setting aside any "conspiracy" theories, why has there been such a spate of negative papers and comments, including all the stuff on contamination, none of which detracts from the original paper's findings? The contamination theory is just that - there is no proof that Lombardi et al's XMRV was the result of any contamination. The same applies to the potential generation of the novel virus within the laboratory, while the disease has been around a minimum of 100 years.
I agree we should not be attacking Singh here. She had all the best intentions, and did what she feels was as thorough a study as possible. It's disappointing, for sure -- but we can't attack everyone who doesn't find what we want them to find.
ReplyDeleteWe are all frustrated as we are all so severely ill and this pushes us that much farther from a cure, but we can't blame Dr. Singh for that. She is a highly reputable scientist who takes ME/CFS very seriously.
That being said, contrary to what Dr. Singh states in this interview, I would think it would be of great value to test tissue samples of ME/CFS patients, or blood samples of prostate cancer patients known to be tissue positive.
I also agree that this study alone does not resolve the issue. Research must continue, and a full replication study is still in order.
This study certainly isn't conclusive, just like the Lombardi study isn't conclusive. Nothing has been proven yet on either side.
Kassy stated:
"In a recent exchange on Twitter, Dr. Racaniello suggested that what were detected could be antibodies to a very similar virus but not XMRV. In that case, shouldn't that virus be looked for and examined? "
Excellent question.
I wonder if it would be possible for Dr. Mikovits to go into someone's lab and show them how to find the virus. Could she demonstrate? Why not go into the lab at the NIH, draw the blood of someone proven to be positive and show them XMRV. I don't understand why that can't happen. It would only take one sample. Then, they could see how to do it and that it was there and all the questions would disappear.
ReplyDeleteThe commenters accusing other commenters of "attacking" Dr. Singh are spewing logical fallacies all over the place. In just a few words they've used ad hominem, appeal to authority, red herring, and straw man fallacies rather than attempting to address legitimate criticisms.
ReplyDeleteIt is not a knock on the Lights either to question the effectiveness of these new assays. Alan Light is a professor of anesthesiology not a retrovirologist. So Retrovirology and viral assays are not really his area of expertise.
ReplyDeleteI admire Dr. Light and know he wants to help ME-CFS patients but again he is not a retrovirologist or a virologist. So he may have tried everything he could think of to find XMRV but if it's not his area I'm not sure that his ideas would be very comprehensive in this study.
Singh, Light, Bateman et al vastly overstepped when they concluded that their study indicates people like Dr Snyderman and Dr Deckoff-Jones shouldn't be trying antiretroviral drugs. Their study hasn't the capacity to come to such conclusions, so I have to wonder why they even spoke to the issue.
ReplyDeleteThere is so much research out there that shows HGRVs like XMRV and the MLVs are more easily found in lymphatic tissues and reproductive tissues that I find Dr Singh's excuses for not looking there to be disingenuous and her statement that it isn't easy to do, to be a misdirection. Reminds of me of the CAA Trojan Horse saying something like you can't go sticking patients in the spinal chord, in response to the study that found distinctive proteins in spinal fluid of CFS patients.
Anything to keep from having a valid test or biomarker for ME/CFS?
If either of them asked patients whether they'd rather continue to decline and suffer and die or give a tissue biopsy or "suffer" a stick to the spinal chord, we all know the answer would be "Where and when?" I can't believe that Dr. Singh doesn't know this, so why all the dissembling and "correction" after publishing and why the outlandish conclusion regarding patients and doctors deciding their own treatment plans?
I smell something rotten in Utah. It was really a thinly veiled rebuttal to the work at WPI and the University of Nevada, without actually saying so. And once again, they didn't actually replicate the study published in Science. They used a different protocol and then claimed their findings nullified WPI's findings. It's just a little more subtle than Myra McClure exclaiming she's 1000% sure there is no XMRV in UK, but not much.
To characterize CFS as being an illness whose primary symptom is fatigue, as this study did, with the participation of Bateman whose clinic only has "chronic fatigue" in its name (not syndrome) is also telling.
I'm quite certain the commenters mentioning "attacks" on Dr Singh are not referring to the many reasonable comments here containing valid questions and criticisms regarding Singh's methods, but rather those spouting conspiracy theories, accusing her of being bought off, etc. Look at the very first comment, for example, accusing her of having "succumbed to political or financial pressures."
ReplyDeleteI, for one, am grateful to the person/people commenting on various blogs to say it's not acceptable to attack a scientist in this way simply because we don't like the results, nor is it representative of how most of the CFS community feels. It needs to be stated because there is a vocal minority who I've seen use very emotional, often unfair arguments on scientific blogs etc, who feed into the perception of us as hysterics who want to believe whatever we choose about our disease, evidence or not. I think the commenter who was attacked here for this was very compassionate, saying it comes from "deep distress", which I agree with and also sympathise with, but wish some could rein it in and not lash out unfairly at scientists like Singh who are on our side, nor at commenters who are reasonable in criticising attacks and unjustified conspiracy thinking.
It was completely unfair to jump on the commenter who criticised attacking good scientists and say they are someone who is determined to paint me/cfs patients as 'crazies'. Nothing is mentioned about anyone being 'crazy', simply that such attacks are unjustified and we make ourselves look bad. How is this the 'oldest trick in the book'? There is a vast difference between saying a vocal minority attacking a sympathetic scientist and suggesting conspiracies is unreasonable and not a fair representative of a more reasonable majority of ME/CFS patients, and non-believers in ME/CFS painting us as crazy. That commenter does not deserve to be lumped in with the latter, when his/her comments and the psych lobby's thinking are day and night. There is yet another conspiratorial underpinning to that attack, and whomever is coming to these conclusions, please, you need to check yourself.
Singh keeps telling people it's a different virus in prostate cancer patients, not XMRV. If her samples don't contain XMRV then they cannot be used as a control, and this all contradicts what is said in Shin et al.
ReplyDeleteV99
I am waiting to see what the Canadian studies say to help evaluate the debate on XMRV and I will go from there. Please report on these studies when they are published Mindy. For me, they will keep the XMRV door open or close it.
ReplyDelete