Cell-free DNA levels

[SNT Gatchaman]

Post moved from
Mitochondrial dysfunction and the pathophysiology of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) 2012 Booth et al



It was recently prompted by Joan's comment on cell-free DNA.

My cell free DNA is well out of spec. Abnormally high. I have no idea why this simple, cheap and I'm assuming reliable test is not used more often in pwME and similar. The Breakspear have been testing this for a decade or so. Not sure if they have published this.

From memory the method was straightforward, my results were consistent and the test offered by accredited UK lab.

Coupled with more recent papers on neutrophils and NETs in LC that were on my radar.

Eg Plasma proteome of Long-COVID patients indicates HIF-mediated vasculo-proliferative disease with impact on brain and heart function (2023) —

Compared to age and sex-matched acutely ill COVID-19 inpatients and healthy control subjects, Long-COVID outpatients showed natural killer cell redistribution with a dominant resting phenotype, as opposed to active, and neutrophils that formed extracellular traps.

[Maybe we should move these posts to the Neutrophil Extracellular Traps thread or a more general cell-free DNA thread?]

Perhaps it would be necessary to look for differences in cell-free DNA immediately after exercise and/or during PEM.

Same idea and could be straightforward. I note JE has commented on problems with neutrophils and NETs evaluation and theory.

I wonder if this could be relatively low-hanging fruit for hypothesis testing about causes of PEM. Ie is high baseline but even higher post-exertion cfDNA/NETosis contributing to physiological degradation and symptoms?

Well-characterised patient group vs healthy normal vs healthy sedentary vs healthy trained athlete groups. cfDNA is low in inactive people, so if it's high in ME at baseline that's an interesting starting point. Is it all neutrophil-derived and does this point to increased baseline apoptosis/NETosis? Does it go sky high following an exercise challenge or is it just the same degree of elevation as sedentary controls? Healthy people will go high, but trained athletes show much less increase.

I'm working through reading these, but in case there's interest here are some refs —

Elevated cfDNA after exercise is derived primarily from mature polymorphonuclear neutrophils, with a minor contribution of cardiomyocytes (2023, Cell Reports Medicine)
Physical Exercise Promotes DNase Activity Enhancing the Capacity to Degrade Neutrophil Extracellular Traps (2022, Biomedicines)
New Perspectives on the Importance of Cell-Free DNA Biology (2022, Diagnostics)
Physical activity specifically evokes release of cell-free DNA from granulocytes thereby affecting liquid biopsy (2022, Clinical Epigenetics)
cfDNA Changes in Maximal Exercises as a Sport Adaptation Predictor (2021, Genes)
Exploring the Potential of Cell-Free-DNA Measurements After an Exhaustive Cycle-Ergometer Test as a Marker for Performance-Related Parameters (2017, International Journal of Sports Physiology and Performance)
Increases in Circulating Cell-Free DNA During Aerobic Running Depend on Intensity and Duration (2017, International Journal of Sports Physiology and Performance)
Acute Severe Exercise Facilitates Neutrophil Extracellular Trap Formation in Sedentary but Not Active Subjects (2013, Medicine & Science in Sports & Exercise)

 

[Hutan]

A relevant thread:
Mitochondrial dysfunction and the pathophysiology of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) 2012 Booth et al
This refers to the Myhill-promoted Test that included cell-free DNA levels.

And another:
Elevated cfDNA after exercise is derived primarily from mature neutrophils, with a minor contribution of cardiomyocytes, 2023, Fridlich et al
This study in health people found massive increases in cell-free DNA following exercise, mostly derived from neutrophils. The cell-free DNA has a very short life, with levels returning to normal with an hour of exercise.

It uses a technique to identify the cells that the cell-free DNA came from, which could be very interesting to apply to ME/CFS samples.

 

[Joan Crawford]

A relevant thread:
Mitochondrial dysfunction and the pathophysiology of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) 2012 Booth et al
This refers to the Myhill-promoted Test that included cell-free DNA levels.

And another:
Elevated cfDNA after exercise is derived primarily from mature neutrophils, with a minor contribution of cardiomyocytes, 2023, Fridlich et al
This study in health people found massive increases in cell-free DNA following exercise, mostly derived from neutrophils. The cell-free DNA has a very short life, with levels returning to normal with an hour of exercise.

It uses a technique to identify the cells that the cell-free DNA came from, which could be very interesting to apply to ME/CFS samples.

Potentially an interesting area for study, along with other known responses to exercise and recovery.

It's been a while back that I read up about free actin and myosin levels in the blood plasma. From memory, there was one small study completed in Spain about this in pwME. I contacted the author at the time it was published and they didn't reply. I discussed this with Willy Weir too. I don't recall seeing anymore about this since.

It would be illuminating to test pwME pre and post exercise challenge on these well-known and straightforward to test methods. I suspect these would show up that all is not as it should be.

 

[SNT Gatchaman]

The cell-free DNA has a very short life, with levels returning to normal with an hour of exercise.

So it would be important to follow this at eg 1, 4, 24, 48 hours. The short half life in the normal situation will be (partly?) predicated on the amount of DNases, which is increased with regular training - clearly not something we can do once the disease is established, with limiting PEM.

 

[SNT Gatchaman]

Epigenetic liquid biopsies reveal elevated vascular endothelial cell turnover and erythropoiesis in asymptomatic COVID-19 patients (2023, Preprint: BioRxiv)

Analysis of cell-free DNA methylation and histone modifications allows the characterization of cellular turnover or death taking place inside organs, as well gene expression program operating in cells prior to death and release of cfDNA. In the case of solid organs, this is equivalent to a standard biopsy, with the advantage that information is summed across the entire organ. In the case of the immune cells, cfDNA informs on immune and inflammatory processes taking place within organs, which are not reflected in blood cell counts.

The finding that even patients with asymptomatic disease have elevated levels of vascular endothelial cfDNA suggests that COVID-19 causes a sub-clinical increase of vascular turnover, via either direct viral damage or via immune mediators. As long-covid can develop even in patients that had a relatively mild disease, it is particularly interesting to determine if cfDNA abnormalities in mild cases are prognostic of long-covid.

 

[EndME]

Epigenetic liquid biopsies reveal elevated vascular endothelial cell turnover and erythropoiesis in asymptomatic COVID-19 patients (2023, Preprint: BioRxiv)

I can't judge the relevance of this work, especially not without reading it, but just reading the abstract it seems to be slightly in line with Rob Wüsts work?