Mast Cell Activation Syndrome (MCAS) - discussion thread

[hallmarkOvME]

You are not to know.... I.... have spent much of my time trying to help set up high quality research and advocate for good clinical guidelines.

Sorry if I asked already.... What's the difference between diagnostic consensus criteria and "good clinical guidelines"?

I am retired from research so have no competing interests and no investment in any particular theory, just good science.

I tend to keep away from popular medical science books and stick to research publications. However, I have seen enough of the writings of these authors to know that the field of 'MCAS' is largely make-believe. You might be able to change my mind - I am always open to that - but having followed the story of misinformation on this for ten years I doubt it.

To the extent that medical positivism is theoretical, I suspect you have some investment in that, no?

How do you distinguish between "good" and "bad" science?

The books I mentioned are not popular, and the Maitland articles can only be found in research publications.

How do you know you're sample of these writing is large enough? Especially without a theory helping you along?

A useful index of the validity of a clinical category is a reasonably precise measure of prevalence. For 'MCAS' I have seen figures that vary by about 100-fold. That is not a useful category. Either it is as common as some claim, in which case it ought to be better defined by now, or it is a rare genetic group defined by abnormal tryptase metabolism or some such. Nobody seems to know. Moreover, I know of no reliable evidence for mast cell problems being associated with persistent disabling fatigue. Everything I have seen from epidemiology and lab research suggests there is no relation.

It's still nascent enough to be that prevalent and still not be defined. There are no rules to how long it takes. "Consensus 2" rejects the tyrptase criteria based upon a through review of the literature. The know. I know. Plenty of folks know globally.

I am aware of that but since the evidence for 'mast cell dysfunction' is too vague to be of any use I fail to see the point.

Do you mean the evidence that mast cells dysfunction is vague or how dysfunction presents?

Anaphylaxis is systemic. Which is why there is shock.

But it's the exception, not the rule. That's why I left it out.

I am sorry to appear so sceptical but personal claims of this sort abound for anything and everything including homeopathy, with nothing in it. What is the difference in 'indication' when as far as I know we have no reliable trials specific to MCAS?

I don't believe anyone should ever be sorry for scepticism. Homeopahty is quackery; MCAS is a real disease process.

"Reliable" within which contexts?

I'd recommend you get ye to a database with all the current MCAS literature.

I have no idea what that means. Most people here have no idea what nosology is so it would help to use plainer English!

I was attracted to this forum because of it's purported reputation to do "good" Citizen science; good medical scientists know what nosology is, and KNOW you're a good scientist. A little too positivist for my liking, but that's nothing that make make me think less of a person.

 

[Utsikt]

Sorry to nitpick, but how is "actual" functioning here?

No worries. As JE said, we don’t know what’s actually going on with those symptoms, yet someone claim to know based on very flawed science and reasoning.

 

[hallmarkOvME]

No worries. As JE said, we don’t know what’s actually going on with those symptoms, yet someone claim to know based on very flawed science and reasoning.

"We," who? Errgh. And there's another non-sequitur "actually" I guess qualifying the vague, "what's going on with those symptoms?" Do you mean etiologically? We know they're happening and plenty of high quality science with high quality reasoning exists to demonstrate it. But if you haven't or won't read it, I can't force you. The bulk of what JE et al have done is repeat cry "Nonsense." I'm ready to see some papers that show flawed science and reasoning from those making the claims.

 

[EndME]

Without saying that is anybody's job to do so or that anybody should feel that they have to defend a certain viewpoint I think it might be beneficial for the "MCAS yessayers" to post a study on MCAS that is believed to be of high quality and "MCAS naysayers" to pinpoint where things are "nonsense" otherwise it might seem to some to just be an argument of being an "MCAS naysayer" vs an "MCAS yessayer" without discussing actual evidence. It would be preferable if the study wasn't a book that mostly consisted of storytelling.

 

[Utsikt]

"We," who? Errgh.

«We» as in «all of us», «anyone».

And there's another non-sequitur "actually" I guess qualifying the vague, "what's going on with those symptoms?" Do you mean etiologically?

Yes, as in the cause of the symptoms.

We know they're happening and plenty of high quality science with high quality reasoning exists to demonstrate it.

Please read this comment again. I specifically said I’m not doubting the symptoms are happening:

Just chiming in that opposition to the concepts of MCAS, hEDS, POTS, PENE, etc. does not mean that anyone distrusts someone when they say they experience symptoms.

But if you haven't or won't read it, I can't force you.

Read what?

If you think there are papers out there defending the concept of MCAS, I’d love to read it like @EndME suggested.

 

[Jonathan Edwards]

Homeopahty is quackery; MCAS is a real disease process.

OK, tell us what the real disease process of MCAS is. We have been following the literature here for several years and not found anything convincing. Tell us what we have missed.

 

[hallmarkOvME]

«We» as in «all of us», «anyone».

Yes, as in the cause of the symptoms.

Please read this comment again. I specifically said I’m not doubting the symptoms are happening:


Read what?

If you think there are papers out there defending the concept of MCAS, I’d love to read it like @EndME suggested.

The papers YOU say contain flawed science and reasoning.

 

[hallmarkOvME]

OK, tell us what the real disease process of MCAS is. We have been following the literature here for several years and not found anything convincing. Tell us what we have missed.

Have you answered all my questions yet? They're important to my reply (and so I know you're not dodging).

 

[Jonathan Edwards]

Have you answered all my questions yet? They're important to my reply (and so I know you're not dodging).

Yes, I have given all the answers inasmuch as it is reasonable to expect me to. They make no difference to the process of MCAS you might tell us about.

 

[Jonathan Edwards]

I got to go. But I will return.

Hopefully to tell us what the process of MCAS is?

 

[hallmarkOvME]

Hopefully to tell us what the process of MCAS is?

The onus for that is on you. And that's the disease process, not just the process. But if you've failed, I'll do it for you. Hint: it involves triggers and degranulation.

 

[Jonathan Edwards]

Hint: it involves triggers and degranulation.

I am all ears for more, since that bit any premed student would realise.

PS: I cannot see why the onus is on me to explain the process behind a disease category I don't think means anything when it was you who claimed there was one and it did.

 

[hallmarkOvME]

If you think there are papers out there defending the concept of MCAS, I’d love to read it like @EndME suggested.

Why would you say "think." As if we're imagining the research?

Mast cell activation syndrome: An up-to-date review of literature - PMC

Mast cells are a subtype of white blood cells and are involved in the immune system. These cells contain many chemical substances called mediators, which are involved in the allergic response. The fact that mast cells play a role in many events that ...

pmc.ncbi.nlm.nih.gov

The content's typical. The meat's in it's references. Follow and read them.

Type: "mcas disease process" or just "mcas" into Google Scholar or your favorite scholarly search site (make a pot of coffee first).

Read Amber Walkers' book. Mast Cell's United It's a dumb title, but pretty much every sentence is backed up with paper citations. Includes a great history of the original consensus and and Consensus 2 battle over diagnostic criteria and the tryptase question--that alone will show you legitimate MCAS is (it's also a good example of falsification).

 

[hallmarkOvME]

Without saying that is anybody's job to do so or that anybody should feel that they have to defend a certain viewpoint I think it might be beneficial for the "MCAS yessayers" to post a study on MCAS that is believed to be of high quality and "MCAS naysayers" to pinpoint where things are "nonsense" otherwise it might seem to some to just be an argument of being an "MCAS naysayer" vs an "MCAS yessayer" without discussing actual evidence. It would be preferable if the study wasn't a book that mostly consisted of storytelling.

Which book, Afrin's or Walker's?

 

[Utsikt]

Why would you say "think." As if we're imagining the research?

English is my second language. But because I was asking about your opinion, I don’t think «think» conveys the wrong meaning.

 

[hallmarkOvME]

English is my second language. But because I was asking about your opinion, I don’t «think» conveys the wrong meaning.

My bad. Sorry.

 

[Utsikt]

The content's typical.

From the abstract of the review:

For instance, mast cell activation syndrome is known as an augmented number of cells due to decreased cell death, resulting in clinical symptoms affecting many systems. The main common symptoms include flushing, hypotension, urticaria, angioedema, headache, vomiting and diarrhea. Although the underlying mechanism is not yet clearly known,

This seems like a contradiction. If it is know what causes MCAS, how can it also be true that the underlying mechanism is not yet clearly known?

The meat's in it's references. Follow and read them.

Can you pick one you think is pivotal or especially robust? That would probably be more productive than asking someone to read thousands of pages. I can make a thread for the paper if we don’t have one already.

 

[Trish]

@hallmarkOvME, you might find it interesting to go back to the start of this thread and read the first few pages, and look at some of the other threads linked there also.
People on this forum have been discussing the usefulness or otherwise of MCAS as a diagnostic category for years.

No one here denies that people have symptoms that are sometimes put under the MCAS label, and of course doctors should recognise those symptoms and prescribe appropriate treatments. But the argument some members make is the label itself isn't necessarily useful.

 

[Jonathan Edwards]

The content's typical. The meat's in it's references. Follow and read them.

But that review basically says nobody really knows what is going on or how many people have this syndrome or anything much and any symptom you care to mention might fit the diagnosis. It says some people had a conference and decided to invent a new disease but nobody has so far decided quite what that is.

I cannot see why people here should have to follow the same old paper chain we have followed repeatedly over the years to finally find that none of it adds to much - yet again.

That review tells us nothing useful. Can you tell us something useful about what MCAS is supposed to be? Is there any reason to think it is homogeneous, when there are hundreds of candidate symptoms that most of us get from time to time anyway?

As Trish says nobody is doubting that people feel unwell but some of us are doubting that calling it MCAS is of proven value.

 

[hallmarkOvME]

@hallmarkOvME, you might find it interesting to go back to the start of this thread and read the first few pages, and look at some of the other threads linked there also.
People on this forum have been discussing the usefulness or otherwise of MCAS as a diagnostic category for years.

No one here denies that people have symptoms that are sometimes put under the MCAS label, and of course doctors should recognise those symptoms and prescribe appropriate treatments. But the argument some members make is the label itself isn't necessarily useful.

Ty Trish. I appreciate it. Genuinely. I've done the recommended reading. It's odds with experiences and wisdoms. It eerily reminds me, especially in form if not content, of the same kind of rhetorical sophistry and provinicialism the ME community faced not too long ago, before we gained legitimatevy. All I'm asking, I think, is for the sufferers of MCAS to get the same considerations we demanded as suffers of ME. We should be allies, not adversaries. Fortunately, or perhaps unfortunately, my decrept old body has a foot in both "camps". Maybe that taints my perspective, but I suspect it rather expands and elevates it.

I came with here with great hopes to learn more about PEM and have endeded up feeling ganged up on. This MCAS business is mostly a distraction my PEM goals.

I don't agree with everything Afrin said in his book, or even writes in his plethora of research journal publications, but refusing to read him based on hearsay rathwer than analyze his arguments on their own merits and make up our own minds, is quite an un-scientific (and definitely an anti-epistemologically anarchist) thing to do. And it's borderline egregious to me that no one here, AFAICR right now, has properly assessed Amber Walker's Mast Cells United, or Anne Maitland (not to mention Castells', Valent's, Daen's et al) journal papers.

I know by empirical facthood, sound reasoning, and personally anecdotal corroboration, that I have a true disease called MCAS. And I knowm dozens more like me, and know of thousands more making sacrifices to populate experimental groups?

Read the papers I cited, and the papers they cite, and get back to me. Right now I neeed to get back focusing on PEM and other actions relevant to that.