Adrenergic Autoantibody‐Induced Postural Tachycardia Syndrome in Rabbits, 2019, Li et al

[Ryan31337]

Abstract
Background
Previous studies have demonstrated that functional autoantibodies to adrenergic receptors may be involved in the pathogenesis of postural tachycardia syndrome. The objective of this study was to examine the impact of these autoantibodies on cardiovascular responses to postural changes and adrenergic orthosteric ligand infusions in immunized rabbits.

Methods and Results
Eight New Zealand white rabbits were coimmunized with peptides from the α1‐adrenergic receptor and β1‐adrenergic receptor (β1AR). Tilt test and separate adrenergic agonist infusion studies were performed on conscious animals before and after immunization and subsequent treatment with epitope‐mimetic peptide inhibitors. At 6 weeks after immunization, there was a greater percent increase in heart rate upon tilting compared with preimmune baseline. No significant difference in blood pressure response to tilting was observed. The heart rate response to infusion of the β‐adrenoceptor agonist isoproterenol was significantly enhanced in immunized animals, suggesting a positive allosteric effect of β1AR antibodies. In contrast, the blood pressure response to infusion of the α1‐adrenergic receptor agonist phenylephrine was attenuated in immunized animals, indicating a negative allosteric effect of α1‐adrenergic receptor antibodies. Injections of antibody‐neutralizing peptides suppressed the postural tachycardia and reversed the altered heart rate and blood pressure responses to orthosteric ligand infusions in immunized animals at 6 and 30 weeks. Antibody production and suppression were confirmed with in vitro bioassays.

Conclusions
The differential allosteric effect of α1‐adrenergic receptor and β1AR autoantibodies would lead to a hyperadrenergic state and overstimulation of cardiac β1AR. These data support evidence for an autoimmune basis for postural tachycardia syndrome.

Open access here: www.ahajournals.org/doi/10.1161/JAHA.119.013006
Editorial here: www.ahajournals.org/doi/10.1161/JAHA.119.014084

Funded by Dysautonomia International. From their press release:

Researchers at the University of Oklahoma have published a study on the first animal model of POTS, an essential step in confirming whether or not a condition is an autoimmune disease. Additionally, they report that antibodies similar to those found in POTS patients cause tachycardia in rabbits. Perhaps even more importantly, they have identified a potential new drug that inhibits the effect of the antibodies.

This study demonstrates for the first time a role of adrenergic autoimmunity in the pathophysiology of POTS in two related animal models.

The study also demonstrates that the effects of adrenergic autoantibodies are largely reversed using a compound that blocks the autoantibodies, which was developed by the University of Oklahoma researchers.

 

[Badpack]

Well i have a positiv tilt table and also these antibodies. Getting a plasma exchange next week. So i can tell you pretty soon how imported that is haha

 

[borko2100]

Could these autoantibodies also cause other CFS / ME symptoms like fatigue, PEM, etc. or do they only cause POTS?

 

[JES]

Well i have a positiv tilt table and also these antibodies. Getting a plasma exchange next week. So i can tell you pretty soon how imported that is haha

Nice, let us know how it went. For patients in Europe, it seems almost impossible to get this treatment other than from paying it 100% of your own pocket.

Could these autoantibodies also cause other CFS / ME symptoms like fatigue, PEM, etc. or do they only cause POTS?

Dr. Jonas Bergquist spoke in the latest OMF symposium about having found these autoantibodies in about 70% of their patients at Uppsala, shame there is no video record available of that online.

 

[borko2100]

Nice, let us know how it went. For patients in Europe, it seems almost impossible to get this treatment other than from paying it 100% of your own pocket.



Dr. Jonas Bergquist spoke in the latest OMF symposium about having found autoantibodies in about 70% of their patients at Uppsala, shame there is no video record available of that online.

Then why haven't we heard anything about those antibodies for the last 20 years? And if the problem is indeed autoantibodies wouldnt rituximab have helped?

 

[JES]

Then why haven't we heard anything about those antibodies for the last 20 years? And if the problem is indeed autoantibodies wouldnt rituximab have helped?

Probably the same reason we hadn't heard about the "something in the blood" factor messing up cellular metabolism in ME/CFS until Ron Davis came and did some actual research on ME/CFS patients. I believe Carmen Scheibenbogen was the first to discover these autoantibodies in ME/CFS/POTS patients and Bergquist is now replicating her findings it seems.

According to my doctor who has done collaboration with Uppsala, they have observed a correlation with some of these autoantibody titers and the disease, especially one muscarinic autoantibody, which also came out high in my test results. Sadly, there is no treatment offered yet as it's still research in progress. Regarding rituximab, it's a good question why it didn't work. Scheibenbogen has observed improvement in her trial using immunoadsorption.

 

[Ravn]

Given that we still don't have an animal model for ME, and in light of the something in the blood findings plus the annoying debates over deconditioning, this is interesting:

Other rodent models, such as hind limb suspension to simulate deconditioning, have been proposed for use in POTS. Although many patients with POTS have symptoms of physical deconditioning, such as exercise intolerance and decreased cardiac mass,6 deconditioning does not specifically induce POTS in most humans or animals. Thus, the finding that immunization of rabbits with adrenergic receptor peptides can induce POTS‐like physiological features in vivo is a significant advance for the field.

https://www.ahajournals.org/doi/10.1161/JAHA.119.014084

But there's also a caution not to get too excited too soon:

As mentioned above, the exact prevalence and clinical relevance of these antibodies are still unclear. Another potential issue is how specific these autoantibodies are to POTS as antiadrenergic receptor antibodies have been found in several cardiovascular diseases as well as chronic fatigue syndrome, dementia, and ocular disease.3, 9, 10, 11, 12 Although the autoantibodies are clearly functional in the rabbit model, it is unclear whether the presence of adrenergic autoantibodies in participants with POTS is a bystander effect of the primary disease process or whether they are centrally pathogenic. There is a precedence for bystander antibodies in other diseases, such as rheumatoid arthritis, in which autoantibodies are present well before pathologic changes occur and even persist in remission.13

https://www.ahajournals.org/doi/10.1161/JAHA.119.014084

 

[Jonathan Edwards]

I doubt it is worth speculating much about these antibodies. The differences in levels between controls and disease cohorts are not big enough to suggest a role in disease mechanism. When autoantibodies cause disease the differences are much more stark.

 

[Hutan]

The authors separate out autoantibodies to cholinergic receptors from autoantibodies to adrenergic receptors:

Cholinergic:

Several studies have investigated the presence of autoantibodies in POTS and their effects on cholinergic and adrenergic receptors.3 Low levels of antibodies to ganglionic cholinergic receptors were found in a minority of people with POTS (5%–29%). However, low levels of these antibodies were found in healthy volunteers and in people with unrelated autoimmune disorders at similar rates.Although the presence of cholinergic receptor antibodies in POTS has both low sensitivity and specificity,

So few people with POTS have them, and similar numbers of healthy volunteers have them.

Adrenergic:

functional antibodies to adrenergic receptors may be a potential biomarker for diagnosing POTS.3One group has consistently found autoantibodies that bind and activate adrenergic receptors in all patients with POTS tested from 2 different countries.4, 5 These studies found antibodies that activate the β1 adrenergic receptor in most participants with POTS (n=28/32), and a smaller subset of participants with POTS was positive for antibodies that activate β2 adrenergic receptors and act as partial agonists/antagonists to α1 receptors.4, 5However, these are small studies, and it is unknown whether most or all patients with POTS have functional autoantibodies to the α1 and β adrenergic receptors and how many healthy individuals have similar autoantibodies.

The authors suggest that these have autoantibodies been found in all POTS patients tested by one group in small studies. and that it isn't known if healthy individuals are just as likely to have the antibodies to adrenergic receptors.

Is the latter point, that the prevalence of these adrenergic autoantibodies isn't known in healthy people, correct?

 

[Hutan]

And if the problem is indeed autoantibodies wouldnt rituximab have helped?

One issue with B‐cell–depleting therapy is that long‐lived antibody‐producing plasma cells, which do not express CD20, may be unaffected by B‐cell–depleting therapy.

So, how long do long-lived antibody-producing plasma cells live? Googling suggests decades e.g.

using a novel carbon dating technique a recent study showed that (plasma cells) can survive for up to 22 years in the (gut-associated lymphoid tissues)

https://www.frontiersin.org/articles/10.3389/fimmu.2018.02673/full​

Recent studies evidenced the existence of long-lived plasma-cells which could play a major role in the long-term persistence of antibodies after infection or vaccination.
....
Long-lived plasma cells, which have recently been shown to reside in survival niches in the bone marrow, are instrumental in the process of immunity induction and persistence.
....
With another approach, Foote et al. showed that the response to the TI-II pathogen Enterobacter cloacae engenders the formation of BrdU-retaining, antigen-specific long-lived plasma cells in the bone marrow that resist depletion by cyclophosophamide and anti-CD20 treatment,
​

So, if the adrenergic auto-antibodies were produced by long-lived plasma cells, Rituximab and cyclophosphamide wouldn't necessarily get rid of them in any sort of reasonable trial length. ? Indeed, does the existence of long-lived plasma cells keeping safe in niches of the body, mean that the Rituximab trial does not rule out an autoimmune cause of ME/CFS?

 

[Badpack]

The negativ Rituximab trial doesnt rule out an autoimmune cause of ME/CFS at all. There a different types of antibody producing B-cells. Varying on each person they can be produced by earlier B-cells who still have an cd20 epitope or by long living plasma cells who dont react to Rituximab anymore. That was also one of the explanations Fluge gave why the trail could have failed. Also we are talking about antibodies who act like neurohormones. Its not like rheumatism where reducing the antibody count with Rituximab helps you because you reduce the inflammation. There is no real inflammation in ME/CFS. No real inflammation loop you could break through. So you better be off comparing it to something like morbus basedow. Where also antibodies act like hormones. So even a small count of antibodies could be enough to keep you ill. Thats where i dont go along with Edwards opinion.

"I doubt it is worth speculating much about these antibodies. The differences in levels between controls and disease cohorts are not big enough to suggest a role in disease mechanism. When autoantibodies cause disease the differences are much more stark."

I think we are talking about autoantibodies who act like neurohormones that make you sick. Compare this disease to something like primary Hyperepineprinemia or adrenal medullary Hyperplasia.


listen to him and tell me he doesnt sound like a guy with CFS

But instead of real adrenalin you get autoimmune made adrenalin which cant be measured the normal way. And even small doses make you really sick. Its an autoimmune made adrenaline poisoning in my opinion. Thats why i decided to undergo a plasma exchange treatment. Because if its right what im saying it should help me get better. At least for 1 week or so. As a proof of concept.

 

[butter.]

The negativ Rituximab trial doesnt rule out an autoimmune cause of ME/CFS at all. There a different types of antibody producing B-cells. Varying on each person they can be produced by earlier B-cells who still have an cd20 epitope or by long living plasma cells who dont react to Rituximab anymore. That was also one of the explanations Fluge gave why the trail could have failed. Also we are talking about antibodies who act like neurohormones. Its not like rheumatism where reducing the antibody count with Rituximab helps you because you reduce the inflammation. There is no real inflammation in ME/CFS. No real inflammation loop you could break through. So you better be off comparing it to something like morbus basedow. Where also antibodies act like hormones. So even a small count of antibodies could be enough to keep you ill. Thats where i dont go along with Edwards opinion.

"I doubt it is worth speculating much about these antibodies. The differences in levels between controls and disease cohorts are not big enough to suggest a role in disease mechanism. When autoantibodies cause disease the differences are much more stark."

I think we are talking about autoantibodies who act like neurohormones that make you sick. Compare this disease to something like primary Hyperepineprinemia or adrenal medullary Hyperplasia.


listen to him and tell me he doesnt sound like a guy with CFS

But instead of real adrenalin you get autoimmune made adrenalin which cant be measured the normal way. And even small doses make you really sick. Its an autoimmune made adrenaline poisoning in my opinion. Thats why i decided to undergo a plasma exchange treatment. Because if its right what im saying it should help me get better. At least for 1 week or so. As a proof of concept.

I wish you were correct, but if so, why were Prof. Scheibenbogens Immunadsorption studies not successful?

 

[Badpack]

I talked with Dr. Scheibenbogen about the study. It also was just a proof of concept. 10 ppl got an immunadsorption with no further follow up medication or treatment. 9 out 10 said they got an improvement out of this ( mostly for around 2-3 weeks, just as long an immunadsorption without further treatment should help here ). And 3 out of 10 ppl still said they were improved after 1 year. Fr. Scheibenbogen said that she could show that in these 3 patients the count of long lasting plasma cells dropped significantly. So i would say its a pretty good sign for an autoantibody driven disease.

 

[JES]

I talked with Dr. Scheibenbogen about the study. It also was just a proof of concept. 10 ppl got an immunadsorption with no further follow up medication or treatment. 9 out 10 said they got an improvement out of this ( mostly for around 2-3 weeks, just as long an immunadsorption without further treatment should help here ). And 3 out of 10 ppl still said they were improved after 1 year. Fr. Scheibenbogen said that she could show that in these 3 patients the count of long lasting plasma cells dropped significantly. So i would say its a pretty good sign for an autoantibody driven disease.

Yeah and IMO this is the way to go, at least from my engineer's perspective. Simply filter the autoantibodies from the blood and see what happens, if there is improvement you have demonstrated both a disease mechanism and a treatment. I don't know why others aren't pursuing it.

At least in Uppsala they are not looking just at the presence of autoantibodies, but the levels as well, to see if there is any correlation. But anyway, since there is already a method that can remove autoantibodies this selectively, I don't see why it's not hypothetically a superior treatment over rituximab, IVIG or immunsuppressive drugs.

 

[Jonathan Edwards]

Dear @Badpack
You make some valid points but there are a couple of things I would add.

Pretty much all effective soluble antibody is made by plasma cells, none of which have CD20. I was aware of that when we introduced rituximab for autoimmune disease. The rationale for rituximab is actually rather complex and has to do with the autoamplifying nature of an antibody response and the feedback role of antibody on further antibody production.

The lucky thing about many autoantibody producing plasma cells is that many of them are short lived. However, plasma cells making antibody to Ro and RNP for instance are not. Autoantibodies in ME might by from long lived plasma cells so the failure of rituximab does not prove ME is not autoantibody based.

But the plausibility of an autoantibody mechanism has to depend on at least some evidence. I have looked at data on muscarinic and adrenergic receptorsntibodies in ME and controls and the difference hardly detectable. That is not what you see in an autoimmune state that is well understood.

As Ivan Roitt used to say we all have a little bit of antibody to everything. Having something show up on a binding assay is a long way from showing pathogenic efficacy. If the amounts turning up are much the same as normals there is no real reason to think they are relevant.

I agree that autoantibodies would be acting as neurohormones in this case but I don’t see that as particularly different from arthritis or thyroid disease. (I don’t know what morbus basedow is. ) AndI don’t see how that would alter things. You may only need small amounts of antibody but if there are small amounts in normal people it does not take us far.

The problem with plasma exchange is that it only ever has a short lived effect and because of placebo responses and illness fluctuation it would be hard to tell if an improvement meant anything. I am fairly sure plasma exchange was tried in ME and it did nothing.

 

[Badpack]

@Jonathan Edwards

Thanks for the response. Im not a native english speaker so please forgive me any mistakes i maybe make in showing my thoughts now. I didnt measure my autoantibodies with a standard binding assay to just show the amount or just the existence. I used a bio essay, a model with rat cardiomyocytes where the prepared serum was added. With different blockers you can rule out all the antibodies one after another. My ß2 response made the heart cells beat faster for around 40 beats. My muscarinic antibodies around 50 beats. So they have a real pathological role i would suggest.

I see a difference in ME vs. arthritis because you never get the arthritis antibody count to zero with rituximab. And frankly you dont have to because in lowering the count you make the patient a lot better because of the underlying inflammation you reduce. But i believe that with neurohormones, a bit better just isnt enough to help.

Morbus Basedow / Graves disease is an autoimmune disease where the body attacks the TSH receptors. For me its a great comparison because its the only known and proven autoimmune disease with neurohormone autoantibodies. And just like CFS no immunsupression shows any sign of improvement. Often the thyroid gland is just removed. This isnt a very doable venture with sympathetic/parasympathetic nerves. So it comes down to filtering/removing the antibodies for now till aptameres are out of clinical studies to do a better job at it. ( BC007 from berlinCures as an example or the ones used in this study above).

I found 3 plasma exchange case studies and all suggested a pretty good outcome. So im going to try it and we will see i guess.

 

[Hutan]

The problem with plasma exchange is that it only ever has a short lived effect and because of placebo responses and illness fluctuation it would be hard to tell if an improvement meant anything.

It would be fairly easy to have a control treatment though. With a large enough sample, a short term effect should show. Maybe use some objective tests - a response time test, resting heart rate upon waking, temperature upon waking, standing test for orthostatic intolerance?

I used a bio essay, a model with rat cardiomyocytes where the prepared serum was added. With different blockers you can rule out all the antibodies one after another. My ß2 response made the heart cells beat faster for around 40 beats. My muscarinic antibodies around 50 beats. So they have a real pathological role i would suggest.

That sounds so interesting.

Additionally, they report that antibodies similar to those found in POTS patients cause tachycardia in rabbits

Now you are saying, badpack, that your serum causes the equivalent of tachycardia in rat heart muscle cells?

Have you told us about this experiment before? If not, can you explain it please?

(That video is some stem cell derived cardiomyocetes - heart muscle cells - spontaneously and synchronously beating - so cool)​

So, you added your serum to some rat cardiomyocetes. How do the blockers work?

Could that assay be done as an experiment with serum from lots of controls and PwME?

Having something show up on a binding assay is a long way from showing pathogenic efficacy.

Is it possible that , even with similar numbers of antibodies in healthy people and PwME, the pathogenic efficiency is different?

Apologies for my floundering.

 

[Badpack]

@Hutan https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5541141/ i used this method. Its a test for GPCR autoantibodies like seen in CFS. Because of the physiology of the heart you can measure around 15 different antibodies at the moment. Amongst other things a1, ß2, M2, nociceptin, AT1, ET.

So yeah my serum causes the equivalent of tachycardia in rat heart muscle cells, thats right.

 

[Jonathan Edwards]

I used a bio essay, a model with rat cardiomyocytes where the prepared serum was added. With different blockers you can rule out all the antibodies one after another. My ß2 response made the heart cells beat faster for around 40 beats. My muscarinic antibodies around 50 beats. So they have a real pathological role i would suggest.

The paper I have seen using that assay looks difficult to interpret. A bioassay of a human antibody using another species has a lot of potential problems. And that is particularly so for individual case findings. I think a standard binding assay is easier to interpret.

I see a difference in ME vs. arthritis because you never get the arthritis antibody count to zero with rituximab. You dont have to because in lowering the count you make the patient a lot better because of the inflammation you reduce. But i believe that with neurohormones, a bit better just isnt enough to help.

Morbus Basedow / Graves disease is an autoimmune disease where the body attacks the TSH receptors. For me its a great comparison because its the only known and proven autoimmune disease with neurohormone autoantibodies. And just like CFS no immunsupression shows any sign of improvement. Often the thyroid gland is just removed. This isnt a very doable venture with sympathetic/parasympathetic nerves. So it comes down to filtering/removing the antibodies for now till aptameres are out of clinical studies to do a better job at it. ( BC007 from berlinCures as an example or the ones used in this study above).

I found 3 plasma exchange case studies and all suggested a pretty good outcome. So im going to try it and we will see i guess.

I still don’t see why residual amounts of antibody are more important in Graves. I remember a study where Graves responded well to rituximab. It is just easier to use surgery.

 

[Jonathan Edwards]

It would be fairly easy to have a control treatment though.

Is it possible that , even with similar numbers of antibodies in healthy people and PwME, the pathogenic efficiency is different?

Apologies for my floundering.

A randomised double blind controlled trial would certainly be possible and you would not need objective end points if blinded. I just think that better evidence for a link to autoantibodies is needed before exposin* people to the risks.

It is possible that there are different antibodies in ME but then the assays are not showing that up so the ME antibodies might be any sort of antibodies, unrelated to adrenergic or muscarinic receptors- so we are back to first base. If the assay does not pick out something associated with disease we cannot cherry pick and say what it picks out in PWME is special.

When I first mentioned to Angela Vincent, who is maybe the world authority on neuro autoantibodies, that someone had found neuro autoantibodies in ME she immediately said “I hope you are not going to say muscarinic”. I said “fraid so”. She said “oh dear”. End of conversation.