Could the microvascular system – the small capillaries and the red blood cells that run through them – hold the key to energy problems in chronic fatigue syndrome (ME/CFS) and perhaps fibromyalgia? The idea that the blood delivery system – not some metabolic derangement per se – is causing the problems with energy production is not new.
Over a decade ago, brain scans from Dr. Cheney’s ME/CFS patients caught Dikoma Shungu’s eye. The only other time he’d seen lactate levels like that before was in people with primary mitochondrial disorders.
Three vital seed grants from the Solve ME/CFS Initiative allowed Shungu’s work to proceed – work that is still going on today and that’s mushroomed into millions of dollars in funding from the NIH. That work has produced one of the most consistent findings in all of ME/CFS research: Shungu’s five studies have all found increased lactate levels in ME/CFS patients’ brains.
Over time Shungu developed a startling hypothesis. While ME/CFS brains may look like they have a mitochondrial disease, they don’t. That doesn’t mean the mitochondria are working well – they’re not – but they’re not underperforming because of a metabolic problem. Instead, Shungu believes they’re getting pummeled by oxidative stress, resulting, at least in part, from a dramatic decline in the antioxidant system that’s designed to keep oxidative stress in check.
Shungu believes that an immunological change or pathogen triggers the production of pro-inflammatory cytokines and the potent free radical peroxynitrite. When the muffled antioxidant system fails to mop up peroxynitrite, the free radical smashes into and rips up the lipid membranes of cells, and in doing so forms a major menace in ME/CFS – isoprostanes.
Potent vasoconstrictors, the isoprostanes then compress the blood vessels, reducing blood flow and producing a hypoxic or low oxygen environment. That low oxygen environment forces the cells to rely on anaerobic energy production.
In Shungu’s view, then, ME/CFS is not a mitochondrial or metabolic disease; its much simpler than that – it’s an oxidative stress induced micro-circulatory disease. The oxygen the muscles and other energy intensive tissues such as the brain need to produce abundant amounts of energy? It’s there, but it’s just not getting through.
Shungu is not alone in his belief that circulatory problems, not the mitochondria, play a key role in the metabolic problems in chronic diseases. A 2018 review of skeletal muscle performance in metabolic diseases proposed the same idea.
… it may be hypothesized that the primary site of dysfunction with earlier stages of metabolic disease may lie at the level of the vasculature, rather than at the level of the mitochondria. Frisbee et. al.
He also lamented the lack of attention given to the role that problems in the microcirculation may play.
While there has been extensive effort dedicated to determining the major factors that contribute to the compromised performance of skeletal muscle with chronic metabolic disease, the extent to which this poor outcome reflects a dysfunctional state of the microcirculation, where the delivery and distribution of metabolic substrates can be impaired, versus derangements to normal metabolic processes and mitochondrial function, versus a combination of the two, represents an area of considerable unknown. Frisbee et. al.
An Oxidative Stress Disease?
Nor is Shungu alone in suggesting that increased levels of oxidative stress may be playing a key role in ME/CFS. Over a decade ago Martin Pall’s NO ONOO hypothesis – which Shungu’s work is partly based on – proposed that runaway oxidative stress is causing ME/CFS.
The oxidative stress data in ME/CFS is abundant and remarkably consistent. So many studies have found increased levels of one or more free radicals in ME/CFS that Michael Maes, the foremost proponent of the oxidative/nitrosative stress hypothesis in ME/CFS, has proposed redefining ME/CFS as”Neuro-Inflammatory and Oxidative Fatigue (NIOF)”.
Many of Maes’s studies suggest that oxidative stress plays a major role in ME/CFS, including a 2011 study in which Maes differentiated people with ME/CFS from healthy controls using levels of plasma peroxides. Other researchers have had similar results.
Recently, measures of oxidative stress were able to differentiate people with ME/CFS from healthy controls. A 2010 study found significantly higher levels of the free radical malondialdehyde in ME/CFS patients. Five years ago, Meeus proposed high levels of reactive oxygen species (ROS; which cause oxidative stress) were behind the pain in FM and ME/CFS. Jason suggested that low antioxidant levels could be affecting HPA axis functioning. The list goes on and on with at least 8 more studies from 2005 to 2010 found elevations of reactive oxygen species after exercise or at baseline in the muscles and blood of ME/CFS patients.
San Jose University/Stanford Study
Now comes an Open Medicine Foundation funded San Jose State University/Stanford study overseen by Ron Davis which manages a trifecta by bringing oxidative stress, red blood cell problems and the microcirculation together. It’s not the first study to suggest that something is wrong with the red blood cells in ME/CFS. Way, way back in 1989, New Zealand researcher Les Simpson came to this conclusion:
“Samples from subjects with myalgic encephalomyelitis had the lowest percentages of normal red cells and the highest incidence of cup forms. The results provide evidence that myalgic encephalomyelitis has an organic cause.”
and even suggested the altered red blood cell shapes could constitute a diagnostic biomarker. A 2003 study that brought news of increased oxidative stress in ME/CFS patients RBC’s, was followed up by a 2004 De Meirleir and and a 2007 study which suggested the same. Things seemed to be hopping with regard to free radical damaged RBC’s in ME/CFS, but except for a small 2010 study from the Griffith’s group in Australia which found no evidence of red blood cell deformability in ME/CFS, that was it for the next 11 years.
Erythrocyte Deformability As a Potential Biomarker for Chronic Fatigue Syndrome. Amit K Saha, Brendan Schmidt…Anand K Ramasubramanian and Ronald W Davis. Blood 2018 132:4874.
“Altered microvascular perfusion can be a possible cause of ME/CFS symptoms.” Saha et. al. 2018
It was a small but comprehensive study – the type that Ron Davis seems to prefer. Rather than throwing a few measures at a lot of patients, Davis seems, once he thinks he’s onto something, to prefer throwing the kitchen sink at smaller numbers of patients in order to dig as deeply as possible into the problem.
Because red blood cells (RBCs) actually scavenge free radicals, they’re particularly susceptible to damage by them – including changes to their shape. Because RBCs carry the oxygen mitochondria need to power our cellular engines, it’s essential that they quickly and efficiently get from our arteries to our capillaries where oxygen transfer occurs. In order to do that, they need to be smooth, rounded, and above all, elastic.
Once they deliver oxygen to our cells, our RBCs serve as cellular cleaners by removing CO2 – a waste product – and passing it to our lungs where we exhale it out.
Mimicking how our red blood cells operate in our capillaries, the San Jose State University group, lead by Anand Ramasubramanian, PhD, recorded how long it took RBCs to enter two differently sized tubes and pass through them, and how elastic they were (how much squishing they tolerated as they squeezed through the tubes). The “squishing” the RBCs go through increases their surface to volume ratio and allows them to pass more oxygen to the cells.
ME/CFS patients’ RBCs struggled more to get into the tubes (~12%, p<0.0001), took longer to get through them (~17%, p<0.0001) and deformed less (lower elongation index, ~14%, p<0.0001). The highly significant data (p<0.0001) indicated that the deformability problems were very consistently found in the ME/CFS group. The findings suggested that in ME/CFS patients, the red blood cells were likely having trouble delivering as much oxygen to the cells as was delivered in the healthy controls.
Shungu’s brain findings suggest high levels of oxidative stress and low levels of antioxidants are constricting the blood vessels.
The blood vessel constriction is producing a low oxygen environment which forces the cells in the brain to rely on anaerobic energy production.
High levels of oxidative stress are amongst the most consistent findings in chronic fatigue syndrome (ME/CFS).
Our red blood cells provide the oxygen our cells need to do their work. In order to flow properly through the capillaries to our cells they must be round and elastic.
The SJSU/Stanford study overseeen by Ron Davis suggests that ME/CFS patient’s red blood cells are often no longer round and take longer than usual to enter the capillaries and flow through them. Their membranes are stiffer than usual as well and they contain high levels of free radicals.
The red blood cells still contain normal levels of hemoglobin but their distorted shapes and inelastic and damaged membranes may be keeping them from delivering normal amounts of oxygen to the cells.
The red blood cell issues and Shungu’s findings suggesting that narrowed blood vessels are creating a hypoxic or low oxygen environment in the brain provide another possible way to explain for the low energy problems in ME/CFS.
Three more grants by the Open Medicine Foundation and Ron Davis will attempt to further characterize the red blood issues in ME/CFS with an eye to producing a cost-effective biomarker.
Next, in one of the more interesting parts (at least to me) of the study, they found that the ME/CFS patients had significantly lower erythrocyte sedimentation rates (ESR) (~40%, p<0.01). Thirty years later, I still remember my frustration that my one consistently abnormal result – low ESR levels – was equally consistently ignored by my doctors.
Then they found that ME/CFS patients’ red blood cell membranes were 30% (30%!) less fluid (30% stiffer, less elastic) and were consistently (p<0.008) packed with 30% more reactive oxygen species (free radicals).
Digging even deeper, the researchers used scanning electron microscopy to find all manner of strange RBC shapes and other issues (biconcave disc, leptocyte, acanthocyte and burr cells; area and aspect ratio; levels of RBC aggregation) in ME/CFS patients’ RBCs. The fact that recovered patients’ RBCs were normal suggested that the disease was indeed associated with RBC abnormalities.
Finally, as was probably suspected, hemoglobin levels and arterial saturation were normal – the RBCs were carrying their full load of oxygen.
The question then became whether the oxygen was getting through. The problems with deformability suggested perhaps not. The authors proposed that free radicals were damaging the membranes of the RBCs, stiffening them up, and impairing their ability to flow through our capillaries and deliver their vital loads of oxygen to our muscle, brain and other cells. No wonder everyone is so tired!
The results of this study seem to jive nicely with Shungu’s hypothesis that free radicals are constricting the blood vessels to create a hypoxic (low oxygen) environment which fosters anaerobic energy production in ME/CFS.
Combine narrowed blood vessels with damaged red blood cells and you seem to have another very possible explanation for the mysterious energy problems in ME/CFS.
The treatment implications of the study are unclear but they seem to be familiar: find a way to stop the inflammation and oxidative stress while boosting the performance of the antioxidant system. At the last IACFS/ME conference, Shungu reported he used NAC to good effect in ME/CFS and both Dr. Klimas and Theresa Dowell RN are reporting good results with intranasal glutathione to boost brain antioxidant levels.
Engineers Enter the Fray
Who would have ever thought that engineers might hold an answer to ME/CFS? In another demonstration of Davis’s drawing power, a team of engineers has entered the fray. Four engineers participated in the three-day Working Group session that occurred prior to the Stanford Symposium. Bringing an engineering precision to the discussion, they pushed the group with tough questions at times and participated heavily. It was gratifying and quite frankly surprising to see how fully engaged the group was.
Giving the study’s findings, it’s no surprise that the Open Medicine Foundation (OMF) is funding more red blood cell work. The OMF is funding three engineers to write more red blood cell grants. The end goal is familiar to those who know Davis’s work – create a low-cost diagnostic device for ME/CFS.
Creating devices like that is Davis’s forte. Rahim Esfandyarpour, an engineer in Davis’s lab, used microfluidics, electronics and inkjet technology develop a “lab on a chip“. The remarkably low-cost chip can perform complex, minimally invasive analyses of single cells without specialized equipment and personnel. Now Davis is attempting to do the same for the red blood cells in ME/CFS.
The first Open Medicine Foundation grant is to a chemical engineering team lead by Eric Shaqfeh, PhD that will create a 3D model of blood channels which will be able to better characterize what’s going on with the red blood cells in ME/CFS.
That group’s results will be used to assist Anand Ramasubramanian, PhD, another chemical engineer, in developing a “microfluidics” chip that will be used to distinguish the ME/CFS RBCs from those of controls.
Finally, Juan G. Santiago, PhD, a mechanical engineer who participated heavily in the Working Group sessions, will develop an imaging device which will be able to automatically identify and track the position and shape of thousands of RBCs under relaxed and stressed conditions.
The end goal of all this – a diagnostic chip for ME/CFS. If ME/CFS needs anything, it’s a diagnostic biomarker. Let’s wish them luck.
The red blood cell findings were wholly unlooked for in more ways than one. Ramasubramanian’s group at San Jose State University (SJSU) came out of nowhere. SJSU is down the peninsula from Stanford but they weren’t on Davis’s radar at all. Instead, Davis was on their radar. Davis has turned out to be an ace at recruiting researchers, but he didn’t recruit them – they recruited him.
To their credit, Ron Davis and the Open Medicine Foundation recognized a good thing when they saw it. Davis is a molecular biologist – not a hematologist – yet he apparently immediately recognized the potential significance of this group’s findings and he and the Open Medicine Foundation supported them.
The exercise and other studies indicate that people with ME/CFS have an oxygen problem. Either their cells are not getting enough of it or they’re not able to use it.
Shungu has shown how oxidative stress may be constricting the blood vessels and creating a low oxygen environment in which anaerobic energy production dominates. Now this finding of deformed blood cells, damaged membrane, and increased oxidative stress, points to another way energy production may have gotten whacked in this disease.
However it turns out, it feels like this field is slowly starting to come together – cohering around issues of inflammation/oxidative stress, energy production and cardiovascular issues.
What we obviously need is more and more funding and more and more research. The grants by the Open Medicine Foundation stand out because for once an organization actually had the money to quickly follow up on an exciting finding. That’s rarity in this field.
The lightning speed with which the OMF provided these grants indicates how important nimble private research foundations like the OMF are to this disease. No year-long waits are needed to see if an NIH grant application got funded. Private organizations like the OMF, the SMCI, MERUK, the Simmaron Research Foundation and others have the ability, if they’re given the funds, to quickly follow up on promising findings. The SMCI, for instance, kept Shungu’s research alive with three successive small grants which allowed him eventually to get two large NIH grants.