CDC Study Must Include CPET, NK Cell and Viral Testing, Advocates Insist

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Mark Berry invites readers to join 11 organizations and 31 advocates and write to the CDC, asking them to include appropriate medical tests in their multi-site study.

The historical approach of the US Centers for Disease Control and Prevention (CDC) to the study of ME/CFS has not been universally well-received - and that's an understatement. The majority opinion of the ME/CFS community seems to be that the CDC has had its head stuck in the sand, as far as ME/CFS is concerned, ever since CDC epidemiologists finally rolled into Lake Tahoe to investigate the outbreak there in 1984. But in recent years there have been some promising signs that the CDC may at last be starting to take the disease more seriously.

The CDC's multi-site, multi-phase clinical assessment study aims to “describe the differences and similarities among CFS patients,” “improve how we measure illness domains of CFS,” “address the CFS case definition,” and possibly allow patients “to be sub-grouped to improve therapy and allow the underlying biology to be discovered.”

Such a large study, led by a federal agency, represents a major opportunity for patients, both in the United States and around the world. There is at least a chance that it might bring some much-needed clarity to the questions and problems surrounding case definitions and subsets which have dogged ME/CFS research for decades.

So it's a very important study for ME/CFS patients, and it's important too for the credibility of the CDC, so badly damaged in the eyes of the patient community by the scandal over the diversion of funds allocated for ME/CFS research - not to mention more than 25 years of failure to make meaningful progress in the study of an illness that blights the lives of millions of patients. The CDC study is already collecting a mountain of data - but in research, what answers you can find depends on the questions you ask, and the data you collect...and there, it appears, we may have a problem...

Missing Information

Although the study has already collected a vast array of data on clinical history and demographics, and patients have filled in a long list of questionnaires, so far there's been a worrying lack of tests that could help confirm biological abnormalities in ME/CFS patients. More worrying still, at the last CFSAC meeting in May 2013, Dr Unger appeared to indicate resistance to the idea of conducting the very tests that many consider crucial to understanding the nature of the pathology in ME/CFS.

Repeat exercise testing is considered by many to be the fundamental test necessary to confirm post-exertional malaise - widely seen as the cardinal symptom of ME/CFS - but is the CDC prepared to conduct the tests necessary to demonstrate it, or will it deploy other tests that are known to miss this crucial phenomenon? Simon McGrath reported on Dr Chris Snell's recent study of CPET abnormalities earlier this week - both Keller and Vemeulen have also confirmed what many practitioners and patients know from long experience: repeat testing is necessary to demonstrate the distinctive effects of exercise on ME/CFS patients. This finding may be in tune with patients' subjective experiences, but it does need further confirmation in larger studies. What better opportunity than the CDC's large-scale study to explore this crucial question?

A wealth of research has also highlighted the significance of viral infections and immune dysfunction in ME/CFS, but will the CDC even measure NK Cell Function and test for viruses associated with ME/CFS?

It is far from clear that the CDC intends to ask any of these questions: the detail so far on the promised blood testing seems vague at best. And with the CDC having already admitted that their study has not yet found a way to study any of the most severely affected housebound and bedbound patients, there's a considerable risk that the CDC's study may fail to study ME at all - a frightening prospect if its conclusions are going to be interpreted and applied as if they had done so.

What hope is there for a useful outcome from this study if the CDC fails to assess the most promising candidates for biomarkers discovered in the last 20 years of ME/CFS research? What chance that the research will help to restore common understanding to a fractured field if it excludes the most promising tests indicated by the work of ME/CFS researchers? Do the study's findings, and any recommendations for case criteria which may result from it, have a realistic chance of being respected and accepted, rather than opposed by the patient and advocacy community, if the study fails to ask the very questions that many patients, advocates and researchers consider to be the most crucial?

The danger that this study may become yet another missed opportunity - or worse, bury the reality of a serious illness even deeper below a mountain of obfuscation - seems very real to many advocates, who are disturbed by the apparent intention of the CDC to exclude crucial evidence from the study.

Letter to the CDC

With these concerns in mind, on July 22nd, 11 patient organizations (including Phoenix Rising) and 31 patient advocates wrote to Dr Unger, Secretary Sebelius, Dr Koh, Dr Frieden, the sites participating in the CDC study and their clinicians, and the members of CFSAC, urging them not to rely on self-reported measures but to include objective measurements in their study. Specifically, the letter calls for the inclusion of 2-day Cardiopulmonary Exercise Testing or CPET (using the Stevens Protocol) and laboratory tests to measure Natural Killer Cell function and viral load, including enteroviruses.

The letter includes an extract from the CFS Advisory Committee meeting of May 2013, reminding Dr Unger of the testimony of Fred Friedberg that post-exertional malaise is "uniquely important" in the essence of this illness, and of Steve Krafchick who said that he would "get down on his knees and plead" with Dr Unger for the integration of neuro-psych testing and CPET into the study because it represents "the most objective evidence that you could ever hope to get", adding: "patient report is nice, and it’s cheap, but if we’re trying to do what you said you were trying to do - don’t miss this opportunity please."

Also included with the letter are academic references in support of the call for the use of CPET, and the list of organizations and advocates who signed it. You can read the letter and supporting information here, and the letter sent to clinicians is available here.

The letter's conclusion sums up its message: "Objective, biological measurements are vital in order to describe the differences and similarities among patients, determine how we characterize and treat patients, address the case definition issues, educate our medical community, and further our understanding of the underlying biology of 'CFS'. For that reason, we urge you to consider incorporating these important tests as soon as possible".

"Please know that we are willing to do everything within our power to work with you and the clinicians involved in order to accomplish this crucial goal. Like you and your colleagues, we want this study to be a success."

So: A wide range of organizations and patient advocates have spoken. Over now to Dr Unger and the CDC: are they prepared to test ME/CFS patients for biological abnormalities, or are their heads still stuck firmly in the sand?

How to Add Your Voice

11 organizations and 31 patient advocates have spoken - now we urge the wider ME/CFS community, including non-US residents, to add their voice and add to the pressure on the CDC to include these objective measurements in their study.

Erica Verillo has produced the following template letter - a shorter version of the letter already sent to Dr Unger - which you can use to add your voice in support of this campaign. Please feel free to edit it and add your own comments...and to indicate your support for the letter on the discussion thread below this article...

Elizabeth Unger, PhD, MD, Chief of the Chronic Viral Diseases Branch

Centers for Disease Control and Prevention (CDC)

1600 Clifton Road

Atlanta, GA 30333

Dear Dr. Unger,

In 2012, the CDC initiated a multi-site, multi-phase clinical assessment study to describe the differences and similarities among ME/CFS patients, determine how we characterize and treat patients, implement an accurate case definition, educate our medical community, and further our understanding of the underlying biology of ME/CFS.

Because the CDC’s multi-site study represents a major opportunity to make a difference for patients – both in the United States and around the world – objective, biological measurements are vital. However, a clinical investigation that does not include proper methodology to obtain objective data will fail to achieve its goals and will result in lost time, lost investment, and worst of all, lost opportunity.

It is absolutely essential that the CDC study include two objective tests which have consistently revealed abnormalities in ME/CFS patients. These tests are:

1) The two-day Cardiopulmonary Exercise Test (CPET). The two-day CPET provides gas exchange and other objective and measurable results “which can’t be faked.” Numerous studies have shown that the 2-day CPET – as opposed to the 1-day CPET – is a reliable and consistent method for measuring post-exertional malaise (PEM), the hallmark symptom of ME/CFS. This test can be done employing technology which has been used in hospitals for decades.

2) Low Natural Killer Cell Function/Viral Load. Abnormally low NK Cell activity and high viral loads are consistent findings in patients with ME/CFS. These tests can be done in many labs around the country and will provide objective, measurable data for comparison purposes.

Measuring and understanding post-exertional malaise (PEM) is crucial to this study. PEM is not only the primary symptom that distinguishes ME/CFS from depression, deconditioning, and other fatiguing illnesses, it is the ME/CFS sufferer’s main obstacle to daily activities, gainful employment, and leading a normal life.

Please include the 2-day CPET and tests for NK-Cell function and viral load in the CDC’s multi-site study.

Thank you,

(Your name, City and State, or Country)

Phoenix Rising is a registered 501 c.(3) non profit. We support ME/CFS and NEID patients through rigorous reporting, reliable information, effective advocacy and the provision of online services which empower patients and help them to cope with their isolation.

There are many ways you can help Phoenix Rising to continue its work. If you feel able to offer your time and talent, we could really use some more authors, proof-readers, fundraisers, technicians etc. and we'd love to expand our Board of Directors. So, if you think you can help then please contact Mark through the Forum.

And don't forget: you can always support our efforts at no cost to yourself as you shop online! To find out more, visit Phoenix Rising’s Donate page by clicking the button below.

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Mark - I tried both links in this para and they didn't work for me - I got a Googledocs page each time but without a document:

"Also included with the letter are academic references in support of the call for the use of CPET, and the list of organizations and advocates who signed it. You can read the letter and supporting information here, and the letter sent to clinicians is available here."
Mark - I tried both links in this para and they didn't work for me - I got a Googledocs page each time but without a document:

"Also included with the letter are academic references in support of the call for the use of CPET, and the list of organizations and advocates who signed it. You can read the letter and supporting information here, and the letter sent to clinicians is available here."
Hi Sasha,

Are you logged in to google? Only the links work fine for me. Not sure if logging in is a factor - you know by now how I am with technology - but it might be :)
Hi Sasha,

Are you logged in to google? Only the links work fine for me. Not sure if logging in is a factor - you know by now how I am with technology - but it might be :)

Oh! I am now and can see it. Pity people need a google account to see this.
You don't need to log into google. They are publicly viewable documents.

These are the two links from that paragraph, in case helpful:

Can you see the docs when you're logged out, Bob? I couldn't - it told me I had to sign in.

Anyway, technicalities apart, it's interesting that the letter to clinicians is to those clinicians who've signed up to be part of the study - a great piece of advocacy, I thought, going straight to the clinicians on the ground and bypassing Dr Unger. Those clinicians need to be aware of the issues themselves.
Thanks, Mark, and to everybody involved in this.

I often use my dry sense of humor (which is not always apparent to everybody) to try to cheer up folks on the internet groups, but on this subject we need to be SERIOUS. There is a long history of prejudice at the CDC towards the ME/CFS community and especially patients. It's not just stigma and bias. While there are some slight indications of movement in the right directions I don't think we can trust them EVER. The problems go into the higher levels of management and always have.

There was an anonymous patient's input about the CDC program on this thread earlier this year.
There was an anonymous patient's input about the CDC program on this thread earlier this year.
Thanks Roy I must have missed that from January. Does this comment from anonymous mean that these things were being tested for:

I have two questions for Dr Unger:
I am an M.E. participant in your multi-center CDC "CFS" study. I meet all the criteria for CCC and ICC M.E. While I was delighted to receive V02 Max testing, immune/virological panels and post-exercise gene expression, I was dismayed at the volume of leading questions in the CDC surveys used, which I believe are biased to an inappropriate diagnosis of depression.
If so in what way? Thanks. Little confused with what went before and what is now being looked at. I realise it is multi-stage, but some clarification of the objective testing done before would be appreciated. Thank you.
Hopefully someone will answer your question better than I can at present due to heavy brain fog.
Anyway! Thanks for this article, Mark.

The outcome of this major CDC study will impact PWME all over the world when it comes out so those of us outside the US as well as within it should be joining in with this.
Can you see the docs when you're logged out, Bob? I couldn't - it told me I had to sign in.
Strange, I just signed out of google and tried those links, and it took me straight to the documents without asking me to sign in. Maybe try clearing your browser's cache first? I think this has happened before with shared google docs; most people seem to be able to see them publicly OK, but a few get asked to sign in. They're shared to 'everyone with the link' so I'm not sure what else to do.
Thanks Roy I must have missed that from January. Does this comment from anonymous mean that these things were being tested for...If so in what way? Thanks. Little confused with what went before and what is now being looked at. I realise it is multi-stage, but some clarification of the objective testing done before would be appreciated. Thank you.
Thanks Roy and Firestormm for digging that up. I tried to find detail on what exactly is being tested but didn't get very far with that. Note that, in the letter, the reference to viral testing and NK cells says 'if not already included in the study protocol', so it seems like nobody else has been able to find out the detail of those tests yet either. I think that's the point really: the devil is in the detail on these things. What exactly you test for, and how, will determine what you will find. And what decisions you make about that will probably depend on your prejudices to some extent, so there's a lot of room for experimental bias in those decisions.

The principle that study protocols should be announced in advance and openly reviewed is gaining a lot of traction these days - I do think that's a far better way to conduct scientific investigations, especially for publicly-funded studies of controversial subjects with significant public interest in the results. It's therefore very important to clarify the detail of these tests, and if the tests being used aren't going to look for the things we want them to look for, we can then press for other tests to be included. At the end of the day, if the tests that the community wants aren't included, it seems likely that the meaning of the study's results will be bitterly disputed and perhaps rejected by the community, which will continue to have consequences down the line, so if the CDC wants to resolve these issues, it's in their interest to include the tests we ask for. I shudder to think how ME/CFS advocacy might evolve in the future if the CDC doesn't get it right this time.

The exercise testing is particularly troubling: the evidence seems to suggest that plain VO2 max testing as opposed to repeat testing won't show up the PEM - I think there's a quite clear and compelling logic to that - and if they only test using a protocol that doesn't find the abnormalities, that could have very negative consequences. The same kind of problem may apply to the viral and immune testing, I just don't know. That's why I'm hoping that we will get some clarification on those details now - we've asked for a reply by Aug 31st so perhaps the detail of these issues will all become clearer by then.
I think this is a very good action. It's one thing to criticise the outcome of a study after the fact but if you can say, 'we pointed out these shortcomings before the study began and the authors chose to ignore them' then that's a whole different ballgame. We need to be on top of these things as they're starting, if we can, before we can be accused of bias because we don't like the results.

I agree that publicly-funded studies should disclose. They should also be disclosing to their participants.
My brain must not be working today... I'm certain someone on this thread wrote that the diagnostic tests in this study remain unknown. How can this be? Don't study participants have to be told what is being done to them as part of 'informed consent'?

Are research study details now part of National Fatherland Security?
Thank you Mark and for all those who were involved in this work.

How appropriate that this follows Simon's article about Dr. Snell's new study on repeated CPET testing.

If the CDC really wants to show that they consider ME a serious disease, as they have stated, this is their opportunity to prove it!

It seems that the CDC wants to put their past history with ME/CFS behind them and have openly admitted that they consider ME/CFS a serious disease. I challenge them that they should put their money where their mouths are. If they are putting money and effort into a multi-site study, do it right - the first time around. This is a great opportunity to show us that:

1- You are listening to us
2- You really believe that this is a serious biological disease
3- You take into consideration the peer-reviewed studies out there that show the hard facts of these objective findings.
4- You are using the funds allocated to us (ME/CFS patients) in the most effective manner
5- There is transparency in what you do

I really hope that this letter will be looked at seriously and taken into account. In either case, it will become apparent soon to all of us watching whether the CDC is serious about this serious illness.
Dr. Unger should be reminded too of the ME Primer's Laboratory/Investigative Protocol. It includes the test for PENE, a 2-day CPET (using the Stevens Protocol), as well as laboratory tests to measure NK cell function and viral load, including enterovirises:

Laboratory/Investigative Protocol: Diagnose by criteria. Confirm by laboratory and other investigations. A broad panel of tests provides a more robust basis to identify symptom patterns, abnormalities and orient treatment.
Routine laboratory investigation: CBC, ESR, CA, P, RBC Mg, vitamin D3, B12 & folate, ferritin, zinc,FBS,PC, Hb A1C,
serum electrolytes, TSH, protein electrophoresis screen, CRP,creatinine, ECG (U+ T wave notching), CPK and liver function,
□ rheumatoid factor, antinuclear antibodies, urinalysis, essential fatty acids,CoEnzyme Q10, immunoglobulins, diurnal cortisol levels, TTG, serotonin
Additional laboratory investigation: (as indicated by symptoms, history, clinical evaluation, lab findings, risk factors) 24 hour urine free cortisol,
DHEA sulphate, ACTH, chest x-ray, hormones including free testosterone, panoramic x-ray of dental roots, amino acid profile,
abdominal ultra sound,lactose/fructose breath test
Further testing with specificity to ME, if and as indicated. Some tests are in the research stage but can identify abnormalities and focus treatment. Viral tests should be interpreted by a physician experienced in these infections.
Pathogen: Enterovirus; Tests: RT-PCR, serology, stomach biopsy
Pathogen: mycoplasma; Tests: DNA-PCR, serology
Pathogen: EBV, CMV, HHV-6; Tests: DNA-PCR, serology, antigenemia
Pathogen: Borrelia burgdorferi; Tests: DNA-PCR,serology, Western Blot
Pathogen: Clamydia pneumonia; Tests: DNA PCR, serology
Pathogen: Parvovirus B19; Tests: DNA-PCR,IgG, IgM,
Immune system profiles: *NK cell function & cytotoxicity; B & T-cell function: IgG,IgG subclasses 1-4;IgA, IgM (shift from T1 to T2), cytokine/chemokine profile panel (94% accuracy): IL-8, IL-13, MIP-1β, MCP-1, IL4,flow cytometry for lymphocyte activity, □ ↑37 kDa 2-5A RNase L immunoassay – defect/ratio & bioactivity, food sensitivity panel, chemical sensitivities, stool for WCB - D-lactic acid bacteria balance, ova & parasites, autoimmune profile, Intestinal dysbiosis:IgA & IgM for intestinal aerobic bacteria in serum, □ ↑ leukocyte elastase activity in PBMCs, IgG food intolerance test,toxoplasmosis
Neurological & static testing: *SPECT scan with contrast - ↓ cortical/cerebellar region cerebral blood flow (rCBF) in the frontal, parietal, temporal and occipital & brain stem regions - more brain involvement indicates increased illness severity,MRI of brain(increased T2-weighted images in high white matter tracts & loss of GM volume) & rule out MS, MRI of spine (dynamic disc bulges/herniation , stenosis), sleep study (stage 4 sleep, sleep pattern & rule out treatable sleep dysfunctions – upper airway resistance syndrome, sleep apnea, etc.)
PENE: A 2 consecutive day comprehensive 8-12 minute cardiopulmonary exercise stress test (measuring heart, lung, and metabolic function) - only ME patients have significantly worse scores the second day & abnormal recovery from exertion. * Exercise tolerance test with expired gas exchange - (2 consecutive days) – measure cardiovascular, pulmonary & metabolic responses at rest & during exercise: peak oxygen consumption VO2 or VO2 at anaerobic threshold (AT) - decline of 8% or greater on test 2 indicates metabolic dysfunction, post-exercise blood analysis - increase in sensory, adrenergic and immune genes - increase in metabolite receptors unique to ME
Energy metabolism/ion transport: ATP profile identifies insufficient energy due to cellular respiration dysfunction
further ATP related parameters, superoxide dismutase and cell-free DNA Respiratory:pulmonary function test Cardiovascular: Tilt table test to confirm OI (70 -80% tilt, measure HR continuously, BP periodically – 30 min or presyncope); Cardiac output decreases - left ventricular dysfunction in the heart; 24-Hour Monitor for suspected arrhythmia, NMH/POTS, myocarditis (Note: Repetitively oscillating T-wave inversions &/or T-wave flats, typical of ME, may be subsumed under non-specific T-wave changes.)
These tests, used to confirm a diagnosis of ME, would allow ME patients to be removed from the more encompassing CFS classification. "The need is not only for a case definition," according to Dr. Unger's June 5 letter to patient organizations and independent patient advocates, “but also for reproducible standardized approaches to applying it, as well as for biomarkers to refine subgroups within the overall CFS population.”
Thanks Mark and all the patient organizations and advocates. I'm thrilled that you guys are on top of this issue and are taking action.

I am concerned that a letter to Dr. Unger probably won't accomplish anything unfortunately. The CPET omission was pointed out to her at the last CFSAC and she didn't seemed moved by the arguments. How many times has she received letters and heated testimony about taking down the CDC toolkit - and she has not even considered taking it down while the new one is being written. All the while, respected doctors and researchers on CFSAC were making the recommendations as well.

The letter to clinicians is a brilliant idea! These folks will probably be the ones that could put the most pressure on her. I would strongly suspect that these good ME/CFS docs would have called this study flaw out to the CDC even in absence of this letter to them (or one would hope).

May I suggest that the patients write each one of the study centers and encourage them to do this correctly? Especially anyone that is a patient at one of these sites. The good doctors should absolutely put their foot down with this nonsense and I can't imagine it would take much arm twisting for them to agree.

Do we have a link to a list of study sites??

So back to the CDC, I believe the real question is:
How do we actually break through to them and optimize our chance for meaningful change? What's our options:

Going above Dr. Unger's head:
If memory serves, I believe just at the last CFSAC (or possibly FDA meeting?), a letter(s) had been written to her superior and I believe she said something to the effect of "he just handed the letter to me to handle". I remember cringing at that very moment. It still might be a valuable route down the line however, but it's very tricky to navigate.

How about going to Sec. Sebellious directly? IMO, she has never done much for us (CFSAC) so it's difficult to imagine she will now.

President Obama? As I understand Bob Miller has lost the White House connection once his contact left the position.

So overall, going above her head may be a strategy for down the road (hopefully there is a better path than I realize).

Getting a meeting with Dr. Unger:
One of the more frustrating problems in dealing with some of these agencies, is not that they deny our requests, but that they don't explain their reasoning for it. How can we present evidence to rebut their argument when we don't know what it is? If Dr. Unger were willing to meet with a small group of advocates and have a meaningful conversation, it's possible we can influence some of the testing. Maybe some docs need to be in on the meeting. I think the most important point would be to get people that she respects at the table, specifically researchers that understand how to set up study designs.

In my opinion, getting these key people (docs, researchers, etc.) to buy into a meeting with her would be vital. Then they could send her a request for it. That would be the path that I think would be most fruitful.

Now, the advocates that sent the letter may already have a stage 2 and stage 3 planned if she does not respond or if she poorly responses. That would be terrific to hear (If so, I realize that they may not want to tip their hand at this point). There are people like Steve K from the CFSAC that may be able to advise us as well (unless it's a conflict of interest for him.)

We really need someone that understands the bureaucracy in Washington I think. I wonder if Wanda Jones might tell us how to complain in a highly-effective, response driven way??
I think using the biomarkers eg nk function particularly bright nk cell function along with other viral markers as well as cd8 t cell dysfunction would be a good start.and are only going to help further research on our illness and make it more respected. hopefully this type of testing will be made available world wide to help diagnose ME.
"Abnormally low NK Cell activity and high viral loads are consistent findings in patients with ME/CFS. "

They're also found in patients with clinical depression, apparently, so it might be better to concentrate on something else. Reduced T-cell responsiveness &/or T-reg abnormality, muscle fibre abnormalities, glial activation, spinal fluid pressure and proteins, autoantibodies, active HHV6 or RNA enterovirus etc? It has to have specificity as well as sensitivity otherwise it allows the CDC to get away with their usual old rope.

They should use a handgrip strength test as well which would allow to include severely affected patients in the CPET.