Webinar: Massachusetts ME/CFS & FM research update - 23 October 2021

Sex, age, illness duration specific differences
In addition to Nath, Lipkin noted that there are sex and age differences in the data e.g. in metabolomics, but had no oestrogen data. I wonder how much effort researchers have made in metabolite analyses to collect samples at the same time in menstrual cycles.

Lipkin hadn't looked at the impact of duration of illness in the exercise stress test because the sample isn't big enough.

Unutmaz's team looked at immune and microbiome profiles in patients with illness durations of less than 4 years, and more than 10 years. He reported that short term patients have the most significant microbial dysbiosis, whereas long -term patients have a microbiome that looks a lot like those of healthy controls. However, the long term patients have the most major metabolic dysbiosis. His team had samples of a decent size. They did find differences between males and females in the immune profiles, but didn't have a lot of males so said the differences might not have statistical power. I think he said something about it looking like the immune systems in younger patients were aging faster, whereas there was much less difference between old ME/CFs patients and their matched healthy controls.

Bateman replied to a question about whether Long Covid is different in male and female patients that she hadn't seen enough male patients to say. Around one third of her Long /covid patients are male.

Maureen Hansen commented that people say that ME/CFS is a heterogeneous disease, but she thinks that people are heterogeneous - genetics, diet, activity levels, infection history, as well as sex and age. But she feels that there is an underlying pathway, she feels hopeful.

Ah, I found it in my notes. I couldn't remember when I wrote the comment above. Inflammatory myositis.

 

Gene expression in individual types of blood cells
One result that I will be looking out for is from Maureen Hansen's team, some work led by Grimson. Maureen noted that comparisons of gene expression in total blood or total lymphocytes between ME/CFS and controls has produced variable and uninterpretable data. Comparing each individual type of blood cell provides greater resolution.

So , they have looked at the RNAs expressed from 270,000 individual immune cells - and looked to see what happens after an exercise challenge. They are starting to know what a typical gene expression looks like for each type of blood cell, so they can identify when the expression of ME/CFS cells is different.

Its currently being analysed but Hansen thinks it's going to be 'extremely important' and may be useful as a biomarker.

Derya Unutmatz's lab is also getting into the specifics of immune cells, particularly the t-cells. He noted that the variety of cells is very complex, and that there can be localised effects in sub-subpopulations, making it hard to pick up differences.

 

The gut microbiome
Lipkin reported that there tends to be a lot more faecal bacteria in the faeces of ME/CFS patients than healthy controls but a reduction in butyrate producing bacteria - although there is quite an overlap between patients and healthy controls. Butyrate is important for regulating gut motility and protecting the gut barrier. Lipkin was suggesting that clinical trials are needed on prebiotics and probiotics to encourage butyrate-producing bacteria in order to improve symptoms. When he was asked for his theory of what is causing teh microbiome changes, he said that he can't say that the changes in microbiome trigger the disease and a wide range of things might lead to the changes. He suggested that large amounts of Metamucil can increase butyrate bacteria.

Derya Unutmatz's team has also looked at the gut microbiome and found reduced butyrate. As noted already, they found that short term patients have the worst dysbiosis, but this is not correlated with differences in metabolites in blood. He commented on the relationships between the microbiome and the immune system. TH17 cells are 'shaped' by the microbiome - they have been found them to be disrupted in ME/CFS (as they are in a number of autoimmune conditions). and MAIT cells recognise bacterial metabolites - they have found MAIT cells are overactive in ME/CFS patients.

Maureen Hansen then came along and, I think, rather poured cold water on the microbiome. She said that her team had done a study in 2016 that found results that are consistent with what Nath, Lipkin and Unumatz have found:
- a loss of species richness in the gut biome
- reduction in butyrate-producing Ruminococcaceae
But they found that the changes were not specific to ME/CFS patients. She mentioned a long list of other conditions that had the same problem including HIV infection, fatty liver disease and Crohn's disease. She thinks it may be helpful to increase butyrate production to improve gut function, but she doesn't think that is the driver of the disease. One of her recent studies found no difference in butyrate in the plasma of ME/CFS patients and controls. And she is not sure we know how to reliably increase butyrate in the gut.

Treatments - LDN and probiotics and more
In a reply to a question about possible treatments, Lucinda Bateman said that she has been prescribing LDN for a long time. She thinks LDN helps fibromyalgia, but is not sure about its role in ME/CFS. She considers it safe and inexpensive. Trials are needed and she thinks one is coming in Canada shortly. Lipkin agreed that randomised trials are needed.

Hansen did too. She commented that probiotics are almost all aerobic bacteria and the gut is an anaerobic environment. she has found papers of probiotics in other conditions, and they actually made people worse. Faecal transplants are more likely to help, but they need clinical trials too.

Avi Nath was also strong on this, saying we must have clinical trials. In what was perhaps a dig at Lucinda for LDN, and Lipkin with his Metamucil, he commented that even if you have something that you think is innocuous, you can be surprised, and humbled. He gave a list of medications that seemed safe but harmed people. I think it was TFNalpha - works in RA but harmful in MS. Glutamate in ALS; monocycline in MS. He said that people shouldn't be saying something is innocuous and give it to people to see what happens - you can hurt patients. It was nice to see everyone urging caution and wanting trials. Given that, I think researchers wanting to do blinded trials to make current treatment practices in ME/CFS more evidence-based should be received warmly by NIH funders.

Yes, Nath said that everyone is identifying immune dysfunctions and that there may be multiple opportunities for modulating them. He said clinical trials at scale are needed.

 

Orthostatic intolerance and cardiovascular issues
Avi Nath does not consider POTS or fibromyalgia to be co-morbidities, but instead part of the illness.

Lucinda Bateman commented that she finds narrowed pulse pressure in both her ME/CFS and Long Covid patients (worse in the LC patients but that might just be selection bias). Cognitive impairment is considerable in Long Covid - reaction times reduce after the lean test. She identifies the lack of awareness of orthostatic intolerance and skill in diagnosing and treating it to be one of the big gaps in ME/CFS.


Scanning for neuroinflammation
Maureen Hansen reported that Shungu in her team has been working on replicating the now quite old report from Japan of neuroinflammation, using PET scans. Covid-19 really slowed the work down, but it is ongoing.

Autoimmunity in ME/CFS?
Nath - yes, we have studied it extensively but additional studies are still ongoing.

ME/CFS, Long Covid and Gulf War Illness
Lipkin noted that 80% of patients report a flu-like illness prior to the onset of ME/CFS. He said ME/CFS may be a spectrum of diseases but there's no question that this is a physiological disorder. Lipkin says his team will be working on similarities and differences between ME/CFS and LC and GWI. He showed an diagram of overlapping circles for the three diseases - but there were some significant issues with the symptoms he chose to put in each illness, I thought.

Maureen Hansen commented that Long Covid has demonstrated that almost all ME/CFS may be post-infectious because e.g. LC can develop a bit after the Covid-19 infection and so the connection might not have been so obvious in a non-pandemic world. She said that LC has made doubters realise that post-viral syndromes are real. She thinks that GWI is not the same as ME/CFS (she didn't give details).

Lucinda Bateman did a study of people on a Utah Long Hauler facebook group- getting those people with an uncomplicated medical history and who had not been hospitalised to answer a survey. There are big problems of course with selection bias, but the long haulers looked very much like people with ME/CFS. Symptoms like coughing and loss of taste were relatively uncommon compared to PEM, and PEM seemed to be similar to the PEM of ME/CFS. The prevalence of OI was 52% - Bateman said that this prevalence increased in those that were seen by the clinic, as probably many people aren't aware of OI. She said massive funding is needed for LC and it's necessary to remind LC researchers what ME/CFS researchers have found.

Derya Unutmatz said something about differentiating ME/CFS, Long Covid and GWI. I have a note that 'they didn't think everything is the same in Long Covid and ME/CFS, but some things might be the same - no details'.

(I think this might be more a reflection of how research proposals that include ME/CFS and get funded will need to be framed. I get a bit frustrated with this idea that ME/CFS-like LC is different to ME/CFS, when ME/CFS is almost certainly triggered by a range of infections. So, it's not two possibly related but different things, but ME/CFS-like LC is a subset of ME/CFS.)

 

Mitochondrial dysfunction
Nath said that they had found nothing to note in the mitochondrial genome. Seahorse analyses did find mitochondrial dysfunction. I've got something here about the cells moving to anaerobic respiration very quickly when stressed and that exercise exacerbates this (I presume this is blood draws after the person with ME/CFS exercises) . There's a lot of work to do to find out what cell types are affected.

Lipkin noted that mitochondria were slow to recover function after exercise. He suggested that an accumulation of citric acid indicated that the energy production cycle is blocked. He commented that there is no question that mitochondrial function is affected in ME/CFS.

Hansen, like Nath, reported that there was nothing remarkable in the mitochondrial genome, and her team had a bigger sample. Her team have also done seahorse analyses of immune cells, and found similar results to what the NIH team found. She commented that this doesn't mean the same thing is happening in other tissues. Nath commented that the NIH team looked at cells from muscle biopsies and didn't find anything. Hansen noted that two types of T-cells (CD4+ and CD8+) have lower levels of glycolysis in ME/CFS, and CD8+ has a lower mitochondrial membrane potential.

Immunology
Lipkin reported an expansion of B cells, the same sort of expansion you see in an infection or autoimmune process. He noted that another group has now independently confirmed those findings (Sato et al).

Unutmatz has done an immune profiling study on 150 patients and age and sex matched controls for 3 time points. Half of the patients were short duration patients (<4 years) and half were long duration patients (>10 years). They identified immune cell and function data points per patient. (They also collected metabolic and microbiome data for these patients). They have done the same thing on 40 Long Covid patients.

Unutmatz reported that MAIT cells are of interest - in some individuals 30% of t-cells are MAIT cells, while in others they are only 1%. MAIT cells can kill intracellular bacteria.

Hansen referred to 'chronic immune activation in ME/CFS'.

Metabolomics and proteins
The Unutmatz team have 500,000 metabolic data points for 1000 metabolites. Derya is very excited about AHR pathway metabolites - aryl hydrocarbon receptor ligands. He also mentioned butyrate, bile acid metabolites and branched chain amino acids. The key goal is to link metabolites with immune and microbiome dysfunction.

Hansen reported about some work led by a person in her team: Germain. They have 45 controls and 60 ME/CFS so far, but will eventually get 90 patients and 90 controls. They have identified 933 known metabolites and 224 unknown metabolites. Metabolites are generally lower in ME/CFS, but there is a considerable overlap. Hansen thinks the key is to look at how metabolites change in response to a provocation like exercise. They have been doing 4 blood draws before and after exercise. Some pathways are different between ME/CFS and controls, regardless of exercise. Some are affected by exercise but quickly recover. But others are affected at a time that matches with PEM/increased symptoms - so that potentially points to causes of PEM.

Hansen had a lot to report, so didn't go into much deeply. They have been doing work on the plasma proteome (Germain) - they believe it indicates pathway and signalling disruption in ME/CFS. A paper has been published (In depth analysis of the Plasma Proteome in ME/CFS). It suggested that the Ephrin-eph pathway is abnormal, and that a ratio of two proteins could be a biomarker for ME/CFS. This work is ongoing. Giloteaux has been doing work on cytokines and other signalling proteins in extra-cellular vesicles, and finding that different proteins are being expressed in ME/CFS and controls.

 

There were a few other issues of interest - a question about coding revealed that this issue is not given enough attention. Lucinda Bateman mentioned that most doctors don't pay attention to coding. She said that ME/CFS had disappeared in the US ICD10 but had been available in ICD-9. (I don't know if that's accurate or not.) It did sound as though coding needs to change if the impact of ME/CFS on society is to be properly understood and faced.

There was some discussion around EBV reactivations, with Lipkin saying that antibody titres can be used and that he hopes to have evidence in 6 months, and Hansen saying that antibody titres don't tell you a reactivation is occurring. And Nath saying he doubts that EBV reactivation is causing the disease.

It's difficult to tell of course, from short talks about investigations that we only have tiny bits of information about and understand even less about, but I did get the impression that some investigators were apologetic about the slow pace of progress. Lipkin seemed to be dredging up old research and talking very vaguely about animal models and a trial of valgancyclovir. No doubt he has been incredibly busy dealing with Covid-19 issues. He said that he didn't want people to be discouraged by 'what we have done to date. Many people are finding similar things now and that reproducibility is very exciting'. Vicky Whittemore noted that Long Covid is an opportunity but it has really slowed progress in the CRCs, with access to labs and supply issues causing problems.

If Nath is talking about clinical trials, then maybe the NIH has some clue about what to trial. But I did feel deflated hearing his reply to 'what was the most surprising thing or thing that needs further investigation?' - 'there is a big difference between the pathways between men and women'. That suggests that in a sample of just 17 people, there was not a lot of consistency in results. and that they probably have not yet discovered the answer to ME/CFS

Maybe the best way for us to think about things is that Long Covid research is mostly actually ME/CFS research - just as post EBV ME/CFS research, and Q fever syndrome research is ME/CFS research too. We just have to make sure the Long Covid researchers don't start from scratch.

Sorry, for going on and on. Writing these posts helped me think about what I heard.

 

Same. She's great about acknowledging her team of researchers too; it feels as though she has researchers covering a lot of what is potentially interesting.