Can you explain more what you mean re: that you can't shake the feeling that this is significant? Also, how do you determine that "M3" is the autoantibody that correlates with your particular symptoms? Is there a list or description somewhere of which specific symptoms correlate with each autoantibody? (I sincerely apologize if you have told me this before and I did not retain it)! Science is not my background at all.
I am interested in M3 (and M4) in particular as it correlates with my symptoms, is shown to be more elevated than the others in other people with POTS/CFS, and is significantly more elevated in me than the rest.
I got the info on its functions from wiki https://en.wikipedia.org/wiki/Muscarinic_acetylcholine_receptor_M3#Effects
I looked at each ones effects.
Basically M3 is responsible for gland secretion (dry mouth), relaxation and constriction of smooth muscles (gut motility = gastroparesis, blood vessels = heart pounding/POTS), secretions from stomach (gastroparesis), and also in diabetes. All of these correlate with my worst symptoms.
Heart pounding and general blood flow issues resulting in fatigue/etc is #1. Gastroparesis is #2. Dry mouth #3. Intolerance to carbs #4 (heart pounding is far worse on higher carb).
I know it's a bit of a shot in the dark as my test results are far less bad than yours or those peoples in the study. I'm just wandering if it's not neccesarily the numbers that matter but the ratios or how active the antibodies are?
I remember talking with someone here who said that if there are antibodies against a certain receptor then the cell can just produce more receptors. This makes sense but how does in know how to do this? Also since M1/etc are activated by the same substance as M3, could the ratio be problematic? Ie M1 works fine, M3 is dulled due to antibodies, body cannot get around this by upping the acetylcholine release as then M1 would get too much activation so it just sits in the middle and hence my symptoms of underactive M3.