Erythrocyte Deformability As a Potential Biomarker for Chronic Fatigue Syndrome, Davis et al (2018)

[Forbin]

About eight months after onset, I underwent a battery of tests at a "famous" otologic institute to try to figure out the cause of my continuous "dizziness." They seemed stumped, but a senior doctor there said that they sometimes saw this kind of dizziness with "vascular insufficiency" to the smallest of blood vessels of the inner ear. On their advice, I tried taking niacin to try get my capillaries to dilate, but it produced no improvement. I wonder if it's possible that the problem was not with the diameter of the capillaries, but rather with the rigidity of the RBC's.

I also wonder if this "rigidity" of the RBC's might be the explanation for a 1975 outbreak at a Sacramento, California area hospital (Mercy San Juan) of what was then termed "infectious venulitis." The symptoms were consistent enough with ME that the event is generally included among lists of ME/CFS outbreaks. The odd feature of this outbreak, though, was what seemed to be inflammation of the "venules," the tiny intermediary vessels that lie between the capillaries and the smallest veins. As I recall, some 200 hospital employees were affected as well as a fair number of people outside the hospital. I've seen photos of patients in this outbreak with what appear to be ugly bruises. A doctor who observed this outbreak wrote an interesting summary of it here: https://me-pedia.org/images/6/6e/Erich_Ryll_Infectious_Venulitis.pdf

[ETA: This article is actually a more thorough account of the Sacramento outbreak written by the same physician. Includes photos: http://iacfsme.org/portals/0/pdf/Summer2011-Ryll-30YearReview-2-46.pdf ]

If it's severe enough, could impaired RBC deformity actually wind up damaging the smallest of blood vessels that they traverse?

[ESR's down to zero are considered in "normal" range, although low values are associated with some conditions, like sickle cell anemia. FWIW, about a month after onset, my ESR was measured as "3." I think this is the only time it was ever measured.]

 

[alex3619]

I do regard this as a biomarker, just not a diagnostic biomarker. It might also be used as an outcome biomarker for assessing treatments.

It still requires a large cohort for replication, including milder severities.

 

[Hoopoe]

Not a top journal after all

 

[ladycatlover]

Back in the 60s I worked as a lab tech, and used to do ESRs. (Using the Westergren method, I have no experience of Wintrobe though I seem to remember they used that at the children's hospital) There's an article on how to do it here. And a bit about clinical significance too.

If you look at the tubes used you can see that the difference between 0 and 5 is really pretty small, at the lower end it isn't really possible to measure meaningfully for comparison with only small differences. I would think that it might be within allowable lab error.

ESR is much more useful for measuring larger differences over time, or to look for a single high reading that prob indicates inflammation. It's a general test of "there's something happening" IYSWIM.

 

[Londinium]

I'll be interested to read the full paper when it's available (or perhaps if it's available - if this is an abstract of what will be presented at their conference then this may be all that is published for now). For now - like so much recent ME/CFS research - it's in the promising-but-needs-replication-and-testing-on-other-illnesses-and-sedentary-controls category. Pleased to see OMF work getting down on paper though.

Re Mark Guthridge's comments, it is true that this appears to contradict the Australian result (Immune and hemorheological changes in Chronic Fatigue Syndrome) but it certainly looks like the method of testing deformability was significantly different, which may well explain this. As I say, I would love to read a full paper on this, in the hope that the discussion section would cover whether there is strong evidence that the result is due to oxidative stress, as discussed in the abstract, rather than being potentially caused by deconditioning; although I imagine deconditioning, in itself, may cause some level of oxidative stress.

 

[Sunshine3]

I do regard this as a biomarker, just not a diagnostic biomarker. It might also be used as an outcome biomarker for assessing treatments.

It still requires a large cohort for replication, including milder severities.

@alex3619 why do u not see it as a potential diagnostic biomarker?

 

[alex3619]

@alex3619 why do u not see it as a potential diagnostic biomarker?

Because while it will have a high sensitivity, it will most likely have a very low specificity, or an inability to distinguish ME from many other diseases. So it can be used as a support test, but not a primary diagnostic test.

It might also be diagnostic in combination with other tests. Combinations of tests need their own specific studies.

 

[Kalliope]

 

[Andy]

Separating out Ron's quote for easier reading

OMF-funded Red Blood Cell Deformability Study Published
Written by Ronald W. Davis, PhD

This paper documents that red blood cells are less deformable in ME/CFS patients compared to healthy controls. It potentially could be a biomarker, and we are proceeding to design new devices that will make a clear distinction between patients and healthy controls. These devices will be hand-held and easy to use by doctors in their offices, or in clinical testing labs. Past work has looked primarily at the shape of red blood cells, which is difficult to quantitate. Our approach will give a clear quantitative number. It measures the ability of red blood cells to deform while squeezing into a capillary, something that blood cells must do for healthy flow. We measure hundreds of cells from each patient, so, because of this, even though the number of patients is low, we get a very statistically significant distinction between patient and healthy cells' deformability. We are putting our energy into developing the new devices as soon as possible.

He certainly seems confident in the results.

 

[Sunshine3]

There seems to be alot of devices in the making.

 

[Jim001]

From Linda Tannenbaum

We are thrilled to share with you that OMF-funded research on Red Blood Cell Deformability by Mohsen Nemat-Gorgani, PhD, of Stanford University, and Anand Ramasubramanian, PhD, of San Jose State University, in collaboration with Ron Davis, PhD, and their teams, has just been published in Blood Journal. This important research could lead to a potential biomarker and diagnostic test.

This critical study has been fully funded by Open Medicine Foundation (OMF) through the support of our generous donors. I extend my personal thank you for your support of our mission to end ME/CFS. The OMF community is standing strong together in support of this urgent research.

Please read the summary from Dr. Ron Davis and the publication below. Every day, together we are breaking ground and moving closer to answers.

So it seems it is published in Blood Journal..

 

[Russell Fleming]

I must admit I am confused about where it is exactly published and what kind of publication it is. But aside from that it is rather pleasing I must say to see the team publish.

Not that I understand how important this might be, or whether it is unique to ME/CFS. But I understand much larger cohorts are necessary that include comparisons with e.g. sedentary, healthy and other neurological perhaps disease controls.

And I am a bit worried that we need new technology that has yet to be invented to test for a possible biomarker. I think when we have to sell something like this to 'the established medical world' it will be that much harder.

But I'm looking forward to trying to read the full paper and hearing from others who are far more capable than me what it's really all about!

 

[JemPD]

I must admit I am confused about where it is exactly published and what kind of publication it is. But aside from that it is rather pleasing I must say to see the team publish.

Not that I understand how important this might be, or whether it is unique to ME/CFS. But I understand much larger cohorts are necessary that include comparisons with e.g. sedentary, healthy and other neurological perhaps disease controls.

And I am a bit worried that we need new technology that has yet to be invented to test for a possible biomarker. I think when we have to sell something like this to 'the established medical world' it will be that much harder.

But I'm looking forward to trying to read the full paper when it's out and hearing from others who are far more capable than me what it's really all about!

well you took the words out of my mouth there @Russell Fleming

I must say i am missing @Jonathan Edwards' input on these things. (assuming i understand why he's not around but i still miss his input )

 

[alex3619]

And I am a bit worried that we need new technology that has yet to be invented to test for a possible biomarker.

Even Ron has said that the early testing needs to be improved. I might be mis-remembering, but I think Ron said the first instrument used five nanometer tubules, they want to re-manufacture to 3 nanometers. The reason is that there is some overlap between patients and controls, but at smaller diameters this overlap will hopefully disappear. If so then expect yet another paper next year or something.

The non-specificity to ME is the biggest hurdle though, just as will many of our tests, including the 2 day CPET. Its not that we know of other diseases these findings are found in, though we do for blood cell deformity, its that we have to reasonably prove that.

 

[Hutan]

The Australian paper Dr Mark Guthridge mentions is from NCNED (Staines and Marshall-Gradisnik) and was done in 2010.
Immune and hemorheological changes in Chronic Fatigue Syndrome

The paragraph relevant to erythrocyte deformability is here:

There was no change in erythrocyte deformability or aggregation between groups, although other studies have confirmed changes in erythrocyte shape in CFS patients, particularly an increase in stomatocytes or lepotocytes [15, 51]. Equally, the Lineweaver-Burk analysis did not indicate statistical significance between the two groups. The most likely consequence of these observations is the heterogeneity of CFS. Nonetheless, observable rheological changes are perhaps associated with the acute phase of CFS while these maybe absent during the chronic stages of the disorder [52]. Notably all CFS participants in this study were in the chronic phase. Thus, erythrocyte deformability and aggregation may not be distinct markers for CFS.

So it looks as though they screened out the possibility of low erythrocyte deformability early in their work on ME/CFS. But yeah, only 6 patients, who had had ME for 5 years or more. And yes, maybe the testing method was not as good as that used by the OMF team. Let's hope so, as it would be wonderful to have a real replicable biomarker, and one that can potentially explain quite a few symptoms.

Do we know if the OMF team are working on replicating their findings in a bigger sample (as well as working on developing cheap hand-held measuring devices)?

We measure hundreds of cells from each patient, so, because of this, even though the number of patients is low, we get a very statistically significant distinction between patient and healthy cells' deformability.

Hmm, I don't think statistics works like that and it worries me that this is even being said. The statistics needs to be done at the level of the person as the comparison is between patients and controls. The trial sample size is not the sum of the hundreds of cells tested as they are not each random samples. After a certain point (maybe 50 cells per person?), adding more cells to each patient sample is going to make very little difference to the strength of the estimates.

I mean, yes, you might have a very good estimate of the deformability of the cells from a handful of patients, but it's not necessarily a good estimate of the deformability of the cells from all ME/CFS patients.

For example, you might want to work out the density of buttercup plants in fields across a country. If you count all the buttercups in a few fields, you will have an excellent idea of how many buttercups plants there are per hectare in those fields. But it won't tell you a lot about the density of buttercups in fields across a whole country. Instead, you'd be much better off counting the number of buttercups in small samples from a lot more fields (as well as stratifying your sample so that you take some samples from wet fields and some from dry fields and some from farms that are highly managed and others from farms where the farmer takes a laissez faire approach to pasture composition etc.)

 

[alex3619]

you might have a very good estimate of the deformability of the cells from one patient or even a handful of them from testing hundreds of cells, but it's not necessarily a good estimate of the deformability of the cells from all ME/CFS patients.

This is indeed one of the issues.

 

[Esther12]

From Linda Tannenbaum

So it seems it is published in Blood Journal..

When you click on the 'table of contents' for the article it takes you to this collection of abstracts from a conference: http://www.bloodjournal.org/content/132/Suppl_1

That's quite different to a normal issue of the journal, eg: http://www.bloodjournal.org/content/132/21?current-issue=y

I don't know what exactly that means for bragging rights over journal prestige. For results like this it doesn't really matter where something is published so long as the results hold up under independent replication imo. If this is a non-peer reviewed conference abstract of no real standing, but leads on to a solid test for identifying problems of many of those with CFS then that would be more than enough!

 

[Bombino]

Someone posted on Phoenix Rising that the paper has been accepted for publication but is not yet online.

 

[Simon M]

I mean, yes, you might have a very good estimate of the deformability of the cells from a handful of patients, but it's not necessarily a good estimate of the deformability of the cells from all ME/CFS patients.

Perfectly put. I am concerned about this claim: it would explain how they get such a small P value from the tiny sample, but that P value does not tell you how likely the finding is to hold up in the wider patient population. On the letter is what we need to know.

There is another issue. IIRC, statistical theory says that you need a sample of at least 20 patients per group to have confidence that the sample is representative of the wider population (which is why you see very few studies published with fewer than 20 individuals per group).

 

[Trish]

I think it's a pilot study testing their new equipment, and demonstrating that it is showing up between group differences. I agree it's far too soon to know whether it will be a useful biomarker, or what the implications are for explaining symptoms or designing treatments. But it does look like a promising start. I agree the p values are pretty surprising for such a small sample. We won't know how to interpret them until we see the raw data - I hope that will be published.

From what Ron Davis said at the symposium, they are working at the moment on developing technologies for lots of possible biomarker tests, then they will test them all with larger samples to see which stand up as reliable and consistent in distinguishing pwME from both healthy controls and people with other conditions.