With regard to 2,3 bisphosphoglycerate, there was an interest in this in the late 90s but repeated testing (probably unpublished) could not confirm a deficiency. If this is normal then lactic acidosis is not present. In fact, privately, I was informed that repeat lab testing shows high 2,3bpg, which indicates alkalinity not acidity. However as a marker this is a time average .. it indicates (indirectly)
average blood pH . Spot pH will depend on activity, and the activity we use to get a test done may make us acidic. So only in a fully rested state will we get to see alkalinity, and even then not until a while after activity stops.
We will indeed produce lactic acid, but its not that we are stuck in glycolysis but the Krebs cycle cannot ramp up to meet need. Why this is happening is still being debated and investigated. There are lots of theories, and most have some evidence for them. It may also be that several theories are right but its combinations of things or right for different subgroups.
At rest though, in milder patients, we should not see much lactic acid in blood. Now, we might in spinal fluid if our brains are being pushed. In exercise we can expect huge rises in lactic acid.
I first got interested in this line of research in the 90s. Its been looked at for that long. However a decade and a half of testing has failed to find the cause.
All bets are off for the severely disabled with ME. Just surviving might push them in to lactic acid overload. They are the people most at risk.
This table lists many triggers for lactic acidosis:
Hypoxia and carbon monoxide poisoning have both been considered in ME.
http://wp.nyu.edu/biochemistryshowc...14/01/Biochemj-MulQuiney-Kuchel-MCA-23BPG.pdf
(This paper is not very readable, but this comment comes from the intro.)
The shunt is a name for the pathway in which 2,3 BPG is synthesized. It is also known as the Rapoport Leubering Cycle. It is primarily active in red blood cells. I am unsure it makes much of a difference in other tissues. If it disturbs NADH metabolism then it might mean our blood NAD/NADH ratio might not reflect our tissue NAD/NADH ratio. What is more clear is that the NADH/ATP or NAD/ATP ratio in the blood might be disturbed.
What is of interest here is that any form of hypoxia/anoxia might result in these issues, and that includes a bad NAD/NADH ratio as a possible cause out of maybe hundreds of possible causes.
Since there are a great many factors that can cause this, it may be that we are a population with a range of different issues but similar final result. Or it may be that a combination of factors might drive this, and that combination might vary slightly patient by patient.
This last view is the one I favour ... we know of many risk factors, and some like B12 deficiency, EDS and small fiber polyneuropathy may indicate problems with the regulation of peripheral vasculature, resulting in local tissue hypoxia. I am currently of the view that many factors combine to induce final pathophysiology.