@halcyon sound very interesting! Would you mind posting your sources? Here are a few studies on the roles of adrenergic and muscarinic receptor antibodies in POTS, OH and CFS.
ROLES OF ADRENERGIC AND MUSCARINIC RECEPTOR ANTIBODIES IN POTS, OH AND CFS
A1, A2, B1, B2, M1, M2, M3, M4, M5
These are short names, where A1 stands for "Alpha 1 adrenergic receptor autoantibodies", B1 for "Beta 1 adrenergic receptor autoantibodies", M1 for "muscarinic cholinergic 1 receptor autoantibodies". See "Simple introduction"
here.
POTS (postural ortostatic tachycardia syndrome)
Here A1, B1 and B2 are elevated. A1 blocks receptors for vasoconstriction. This is a bad thing because when standing up, you need a lot of vasoconstriction otherwise all
blood flows into the lower half of the body. This is what happens when you see all in black after standing up. If it takes longer, you faint. To avoid this, your sympathetic nervous system (SNS) will try to constrict the blood vessels. This won't work if you have A1 receptor antibodies, which block vasoconstriction. Hence, the SNS activates more and more, and will try stronger and stronger. Essentially, standing up becomes so stressful as when a healthy person stands in front of a lion. This will make the heart beat more. Here come in the B1 and B2 antibodies, which will make the heart even more prone to tachycardia. The trick is: Receptor antibodies can be agonistic or dysfunctional. So they activate the receptor or switch it off. in POTS, the A1 antibody is dysfunctional, the B1 and B2 antibodies are agonistic:
http://www.ncbi.nlm.nih.gov/pubmed/24572257
Thanks a lot to
@Hip for pointing me to this study!
http://press.endocrine.org/doi/abs/10.1210/endo-meetings.2012.CE.2.OR48-1
There is a preliminary report on elevated levels of M1 and M2 antibodies in POTS patients, however no mechanism is presented as to how these antibodies contribute to the disease:
http://forums.phoenixrising.me/inde...-with-pots-potential-disease-biomarker.44890/
OH (ortostatic hypotension)
There are reports on elevated levels of agonistic B1, B2, M2 and M3. Circulating in the blood stream, these antibodies act as vasodilators. When laying, then excessive amounts of vasodilators do not make so much of a problem. But when standing up, they will cause the body to have a hard time preventing
blood from pooling in the lower half or the body.
B2 and M3:
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3275920/
http://press.endocrine.org/doi/abs/10.1210/endo-meetings.2012.CE.2.OR48-1
B1, B2, M2, M3:
Details from the text body of the paper:
Agonistic M3 receptor antibodies increase the production of nitric oxide ("activation of endothelial nitric oxide synthase (eNOS) activity"). And M2 receptor antibodies inhibit the increase in heart rate seen in POTS ("M2R inhibition of pulse rate and cardiac responsiveness to upright posture")
http://www.sciencedirect.com/science/article/pii/S1933171111002452
CFS
The following are often elevated in CFS:
B1, B2, M3, M4
These are elevated in 20-30% of CFS patients.
http://www.sciencedirect.com/science/article/pii/S0889159115300209
I do not understand the pathomechanism how antibodies to adrenergic or muscarinic antibodies could contribute to illness. Prof Scheibenbogen, CFS researcher at the Charite in Berlin, is obviously convinced that these antibodies are causative or at least contributive to CFS. Otherwise she would not do
this treatment study.
M1:
http://www.ncbi.nlm.nih.gov/pubmed/12851722
Various disclaimers...
- To say it clearly, POTS, OH AND ME/CFS have a myriad of other possible causes. So for example, if you are interested, this is how I got out of ME. And that thread discusses a wonderful new study on CFS causes, which was probably mine. My POTS however stayed and I do have these antibodies discussed above.
- Also, one antibody affects several body systems. So for example, B2 receptor antibodies are involved in POTS, OH and CFS. That is no wonder if one looks at the manifold functions of the B2 receptor. Also, you will have noticed that not all the A1, A2, B1, B2, M1-5 were mentioned above. Guess what, not everything is known yet...