Due to the muscle weakness and difficulty maintaining physical effort in pwME I recall looking into basics of muscle physiology a while back - such as what are actin and myosin - and being a bit taken aback by how little this aspect of physiology had been looked at in pwME. Or perhaps I wasn't looking in the right places!
I found, way back, a paper which if I recall found raised level of free actin in the blood of patients. I recall this was work carried out by Spanish researchers. I contacted the primary author for more information about the paper and I don't think I ever heard back. I can't find it now.
Anyway, I suspected with mild, physical challenge that perhaps free actin in blood might be helping/interesting area to look at in pwME. I spoke with ME knowledgeable general physician and mentioned this to him. He took my musings about this on board. I don't know if this is something he ever followed up on or if this was something pretty straightforward to teat for via mainstream labs?
More recently I saw this:
https://www.sciencedirect.com/science/article/abs/pii/S0889159119307627
Identification of actin network proteins, talin-1 and filamin-A, in circulating extracellular vesicles as blood biomarkers for human myalgic encephalomyelitis/chronic fatigue syndrome
Akiko Eguchiabc1 Sanae Fukudadef 1HirohikoKuratsunedef Junzo Nojimag Yasuhito Nakatomih Yasuyoshi Watanabeefi Ariel E.Feldsteinc
It's not an area I know much about

so I'd be really interested to know if there are groups repeating and investigating this type of work? Maybe of use for diagnosis? Or is that actually a bit more shaky science wise? Might give an indication of why patients have some of the symptoms (especially muscular, pain and lack of repeatability of muscle use) and difficulties that they have?