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Mast Cell Activation Syndrome (MCAS) - discussion thread

Discussion in 'Immune: Autoimmune and Mast Cell Disorders' started by Dakota15, Aug 26, 2020.

  1. Dakota15

    Dakota15 Senior Member (Voting Rights)

    This thread has been split from
    Concerns about craniocervical instability surgery in ME/CFS

    ....I know you have a lot of pull on here @Jonathan Edwards, but I didn't know you didn't believe in MCAS being a real diagnosis. As I live in the States, I have to say that there seem to be a lot of credible doctors who believe that MCAS is indeed very real. I'm just curious, why do you believe it is a "quack diagnosis"? I'd like to understand your viewpoint better..
    Last edited by a moderator: Aug 27, 2020
  2. Jonathan Edwards

    Jonathan Edwards Senior Member (Voting Rights)

    London, UK
    There are a lot of 'credible' doctors in the USA, and maybe elsewhere who believe in nonsense because it sells.
    It is a quack diagnosis because it doesn't actually mean anything. Normal people have mast cells and they get activated and we know what that looks like. There is no pathological 'syndrome' that is different from that and which is not already known under asthma or urticaria or mastocytosis or what has been in the textbooks for decades. The guy who tries to sell this idea, Lawrence Afrin, I thought might be some bright new immunology whizkid with something special to say. But from his videos he comes across as another ageing muddled empire builder who has no real idea what he is talking about.

    Patients need to be aware that this sort of stuff is just guff. There is a tsunami of it available for those who like the ride but it is seriously counterproductive if we want to make people well.

    I am not sure what you mean by 'pull'. I don't intend to pull anything. I just say what I think and try to justify it with evidence. I am sometimes wrong but most times I recognise that if someone points it out. I am pretty sure nobody follows me as a guru. If anything they like me to be an anti-guru! Which I am.
  3. lunarainbows

    lunarainbows Senior Member (Voting Rights)

    It’s interesting you say this because this is what I was thinking too, from reading about it. But I don’t want to dismiss people who are having symptoms of MCAS because I do believe they are definitely suffering from some sort of allergic condition -allergies, asthma, hives - all of which can exist together. Also anaphylaxis. It is incredibly debilitating and frightening to have these symptoms - I was so scared when I struggled to breathe due to allergies - I think it’s really important to get treated. What I was thinking is I don’t understand why all of these have been combined into a new condition.

    Looking into it further, from an American website: https://www.aaaai.org/conditions-and-treatments/related-conditions/mcas

    MCAS is a condition in which the patient experiences repeated episodes of the symptoms of anaphylaxis – allergic symptoms such as hives, swelling, low blood pressure, difficulty breathing and severe diarrhea. High levels of mast cell mediators are released during those episodes. The episodes respond to treatment with inhibitors or blockers of mast cell mediators. The episodes are called “idiopathic” which means that the mechanism is unknown - that is, not caused by allergic antibody or secondary to other known conditions that activate normal mast cells.”

    But do they actually check that no allergic antibody is produced? As far as I know, skin prick tests or anti body tests aren’t carried out (And found negative) to diagnose MCAS? I mean, I was diagnosed a few times with MCAS and no one checked whether or not I had antibodies or did any skin prick tests.

    How are allergies diagnosed anyway? I’ve got hayfever on my record because I have a pollen allergy and my asthma gets really bad, I had no tests done - the fact I get symptoms is enough to say “allergy” for this particular thing. So why are similar / additional symptoms called MCAS and not allergies?

    The symptoms most consistent with anaphylaxis are:
    • Heart related symptoms: rapid pulse (tachycardia), low blood pressure (hypotension) and passing out (syncope).
    • Skin related symptoms: itching (pruritus), hives (urticaria), swelling (angioedema) and skin turning red (flushing).
    • Lung related symptoms: wheezing, shortness of breath and harsh noise when breathing (stridor) that occurs with throat swelling.
    • Gastrointestinal tract symptoms: diarrhea, nausea with vomiting and crampy abdominal pain.”

    Then I looked up symptoms of a normal allergy. They are:

    “Main allergy symptoms

    Common symptoms of an allergic reaction include:

    “Anaphylaxis usually develops suddenly and gets worse very quickly.

    The symptoms include:
    feeling lightheaded or faint
    breathing difficulties – such as fast, shallow breathing
    a fast heartbeat
    clammy skin
    confusion and anxiety
    collapsing or losing consciousness

    There may also be other allergy symptoms, including an itchy, raised rash (hives); feeling or being sick; swelling (angioedema) or stomach pain.”

    So reading that I thought, MCAS seems to describe, what we already know to be, an allergic reaction. So people who are described as having MCAS are having a lot of allergic reactions?! Am I missing something??

    From the website, the treatment for MCAS seems to basically be:

    Anti histamines, the over the counter ones you get online like Cetirizine or loratidine or prescription ones like Fexofenadine, which are already used as a maintenance treatment for allergies: lots of people in the Asthma U.K. Facebook group reported taking these, some were taking a combination of them; every day even, to control their allergies.

    I know some diagnosed with MCAS are taking Sodium Cromulate, to help with reactions in the gut. This is also already prescribed for food allergies, as far as I’m aware.

    The website then also says to combine this with H2 blockers for the stomach like Famotidine, Ranitidine. (This is used for people with acid reflux).

    Also, Montelukast to reduce wheezing (again, already an asthma treatment..)

    steroids for wheezing, (already is often prescribed for severe asthma), edema, hives (again, pretty sure it’s already prescribed if needed)

    Omalizumab (Xolair), I heard about this drug a long time ago for treatment of very severe allergic asthma! And also it’s use for people who have hives that are severe that don’t respond to other things. The American website says this can help reduce anaphylaxis episodes.

    Epi-pen which is already used for anaphylaxis.

    The way I see it, the condition called MCAS is basically using meds that are already used for allergies (with the exception of ranitidine and famotidine), and then just re-using them and saying it’s for MCAS?

    With ranitidine and Famotodine, they reduce stomach acid by reducing histamine in the stomach. Is there any evidence (proper trials) that these meds reduce symptoms of stomach related allergy symptoms? There may be, which is why I’m asking, but I haven’t come across any so far. So far it seems to be just physicians prescribing it because they say it helps their other patients.. very often complex patients.

    Edited to add: from some more searching, it seems that Ranitidine (Zantac) is prescribed for those who have routine allergies too - eg I found accounts of people visiting ER being prescribed it after a cashew allergy, and for other allergies. So again, it is prescribed in some cases for general allergies.


    Just to confuse things, ME-Pedia has a symptom list for MCAS which includes things which don’t really seem to have anything to do with allergies, such as:
    As well as hot flashes and high or low blood pressure...!

    According to ME-pedia:

    MCAS can be difficult to diagnose as the cause of the syndrome is still considered to be unknown. In 2010, a criteria for diagnosing MCAS was proposed by Dr. Cem Akin and colleagues. These criteria suggest that two or more organ systems must be affected; this can include gastrointestinal, cardiovascular, skin, or respiratory. If given anti-histamine or mast cell therapy, the patient's symptoms must improve. Thirdly, the patient should be tested for serum tryptase, an enzymesecreted by mast cells during the peak of a symptomatic episode. If tryptase is >15ng/mL, the patient may have MCAS. Urine and blood tests should be collected more than once to confirm a positive diagnosis. Prostaglandin and histamine levels can be also be tested.[3]

    The other American site also mentions: “Increases in serum mast cell tryptase and in urine levels of N-methylhistamine, 11B -Prostaglandin F2α (11B-PGF2α) and/or Leukotriene E4 (LTE4) are the only useful tests in diagnosis of MCAS.”

    Don’t know about tryptase but again wouldn’t this occur in allergies though?

    I looked up Afrin and he seems to think underlying mast cell issues relate to / explain so many chronic diseases. Whenever I hear that sort of thing I always hear alarm bells ringing in my head..

    And still largely confused. What is it that the proponents of MCAS are saying? There’s a new condition where people have lots of allergies, but it can’t actually be fitted into “asthma / hives / allergies etc” and you don’t see an immunologist and do treatment as you normally would? But you’d use the same medications anyway? With the addition of Ranitidine? It doesn’t make sense to me.

    Edited to condense a paragraph.
    Edited again to add further info about Ranitidine.
    Last edited: Aug 27, 2020
  4. Jonathan Edwards

    Jonathan Edwards Senior Member (Voting Rights)

    London, UK
  5. Hutan

    Hutan Moderator Staff Member

    Aotearoa New Zealand
  6. Binkie4

    Binkie4 Senior Member (Voting Rights)

    I believe I have mast cell irritability, a doctor's diagnosis not mine. I am reluctant to call it a mast cell activation disorder because it seems that getting this diagnosis from an NHS doctor is almost impossible. Interestingly despite this, my GP accepted the diagnosis immediately because there had been a doctor at the practice who had MCAS and he was familiar with its manifestations.

    I believe that is what caused, out of the blue, my anaphylactic reaction to eating a satsuma last November. I am, or rather was, not reactive to anything- grass, pollen, nuts, seafood, contrast in scans- I could deal with them all until I suddenly couldn't, less than a year ago.

    It was a quiet Saturday evening and we had just watched Prince Andrew being minced by Emily Maitlis. I ate a satsuma and all hell broke loose. I was admitted to hospital by ambulance for 5 days with a swelling throat: the steroids I was given by mouth as treatment stuck in my throat.

    The final diagnoses, given by Dr Clive Grattan, dermatologist with recognised expertise in mast cell disorders ( I also had a rash) were that I have idiopathic angioedema and anaphylaxis and I now carry 2 epipens as well as taking antihistamines.

    I had no IgE reactions to later conventional skin prick allergy testing including to a satsuma although i have not dared to eat one since, only clinical testing. I believe a negative response to conventional allergy testing is common for MCAS. A mast cell reaction as I understand it ( but I could be wrong) is not actually an allergy. It was hard to get my head round the fact that you could eat something one day and be fine, but not the next! I have eaten hundreds of satsumas in my life.
    I had no raised tryptase tested twice. Some unusual antibodies were found to be positive. Still being followed up to try to obtain a diagnosis. A nurse called to do another blood test this morning.

    So all changes at age 72. I have outlined this simply as my experience making no other claim than that. I have found that there is a reluctance in NHS medicine to acknowledge MCAS, to quite an extreme extent, oddly reminiscent of another of my illnesses!! Others have written of their MCAS diagnoses so that can't be true for all patients.

    The area of mast cell disorders is very complicated and I have only just begun to scratch its surface so cannot take you into the science of what happens to produce mast cell reactions. Perhaps someone else can? I have added a link to a page from mast cell action at the bottom of the post and will add to it if i find a better one. If you press the links on there to symptoms, diagnosis and treatment there is a summary of where the NHS stands on dealing with MCAS. I think there are those on the forum who can take us a lot further than this with the science, something to do with KIT mutations I think

    My initial concern was to ensure that I didn't have systemic mastocytosis ( too many mast cells rather than misbehaving ones) or any of the more sinister manifestations.

    PS I do have concerns that patients are turning to fb because their doctors are not hearing them. I read daily of people with severe symptoms rejected by their doctors ( told they are over anxious etc etc - where have we heard that before?) and turning to other patients for support. The group I am referring to ( for UKMCAS not EDS/CCI/ Jen Brea's) is highly responsible and does not offer medical advice.

    I am currently mostly only reading on the forum previously described here


    because of a deterioration and diagnosis of other unrelated health issues so unsure when I will be back but wanted to record this on this new thread. I hope it is comprehensible; not good at expressing myself currently.

  7. lunarainbows

    lunarainbows Senior Member (Voting Rights)

    Thank you for your reply in the thread. Please don’t feel any rush to reply or even to reply if you can’t but just writing my thoughts down. I hope that you get some relief soon. :hug:

    So the difference between anaphylaxis / allergies and MCAS, is that in MCAS, the skin prick tests are negative?

    But having a negative result on a skin prick test doesn’t necessarily mean you don’t have an allergy. Although the information online says that having a negative test is usually accurate, it doesn’t say it’s always accurate.

    There are other ways of diagnosing allergies:

    “Intradermal Skin Test

    In intradermal (under the skin) testing, the doctor or nurse injects a tiny amount of allergen into the outer layer of skin. The doctor checks your skin after a set amount of time for results, like with the skin prick test. Doctors may use this test if the skin prick test results are negative but they still suspect you have allergies. A doctor may use this test for diagnosing drug or venom allergy. At this time, there are very few indications for intradermal skin testing for food allergy.

    Blood Tests (Specific IgE)

    If you have a skin condition or are taking medicine that interferes with skin testing, allergen blood tests may be used. They may also be used for children who may not tolerate skin testing. Your doctor will take a blood sample and send it to a laboratory. The lab adds the allergen to your blood sample and then measures the amount of antibodies your blood produces to attack the allergens. This test is called Specific IgE (sIgE) Blood Testing (previously and commonly referred to as RAST or ImmunoCAP testing). This test is a not a good screening test due to the high rates of false positive results. There is no test that can determine how severe an allergy is for someone.

    Physician-Supervised Challenge Tests

    In your doctor’s office, you inhale or take a tiny amount of an allergen by mouth. This test is usually done with possible medication or food allergies. A physician, usually an allergist, should supervise this test due to the risk of anaphylaxis, a severe life-threatening reaction.

    Patch Test

    This test determines what allergen may be causing contact dermatitis. Your doctor will place a small amount of a possible allergen on your skin, cover it with a bandage and check your reaction after 48 to 96 hours. If you are allergic to the substance, you should develop a local rash.”


    According to this, as you experienced anaphylaxis with satsumas, I would have thought you would count as having an allergy to satsumas.

    There are other reasons why skin prick testing can be negative like if you are taking meds while doing the skin prick tests. (Also maybe some other reason relating to the skin of ME patients, who knows?!)


    But other than that, does anyone know why it is that MCAS is not thought of as allergies / anaphylaxis etc? Is it because you don’t always know the trigger or that the trigger changes? But isn’t that then idiopathic anaphylaxis as was mentioned above?

    Because as I outlined above, the treatment is exactly the same as in allergies and all those meds have been used in allergic conditions for quite some time.
  8. Jonathan Edwards

    Jonathan Edwards Senior Member (Voting Rights)

    London, UK
    I think MCAS is not thought of as allergy because that makes it a 'new disease' that Dr Afrin can be an expert on. Hardly anyone except Dr Afrin actually produces literature on this.

    Mast cells are commonly activated in allergy (urticaria, asthma, angioedema) through IgE antibodies but they are also commonly activated through non-antibody pathways. Seafood like lobster and prawns and also strawberries are said to produce mast cell activation responsible for stomach ached vomiting. Most of these reactive cells, like mast cells and macrophages have receptors that can be triggered both through adaptive immunity (antibody) and innate immunity.

    But all this we have known since I was a student 50 years ago. As far as I can see the idea of MCAS is that there are some people suoosed to have odd mast cells, with maybe odd tryptase levels who are more prone to mast cell activation than others but do not have mastocytosis. That may be true but the concerns that it is never clear whether this refers to rare genetic defects (perhaps in one person in ten thousand) or lottos people on the Clapham omnibus - as in figures quoted of 7% of the population.

    I think the situation for MCAS is very much like that for 'hEDS' which again doesnotseemto be anything more than a re-description of some people being a bit bendy. I don't think either are like ME, which is purely defined by a pattern of symptoms, not by some dubious theory of what causes them.
  9. Jonathan Edwards

    Jonathan Edwards Senior Member (Voting Rights)

    London, UK
    I don't think it is fair to criticise doctors for 'not recognising MCAS' when the great majority of the medical profession don't think there is enough to make the name useful - as I have indicated. I think doctors should take symptoms seriously and take note of skin or lung problems due to mast cells - as is a standard part of medical practice. I don't think they should be obliged to take note of diagnostic labels that don't really mean anything.
  10. Dx Revision Watch

    Dx Revision Watch Senior Member (Voting Rights)

  11. Dakota15

    Dakota15 Senior Member (Voting Rights)

    I appreciate your input @Jonathan Edwards. I really do.

    My doctors believe MCAS is part of my ME/CFS picture, but I respect everyone's opinion and viewpoint. I know this field is anything but simple to dissect. I don't intend to de-rail this thread, and I know you've posted a document outlining all the details of your beliefs (if I recall correctly), but in layman's terms (or as 'simple' as can be I guess), and I hope you don't mind me asking this - but what is your belief or what do you think is causing the phenomenon that is ME/CFS for most of us - i.e. post-viral, post-infectious? Mods, again, I don't intend to de-rail here and just wanted to ask a question I was curious about.

    Invisible Woman, Binkie4 and Kitty like this.
  12. Jonathan Edwards

    Jonathan Edwards Senior Member (Voting Rights)

    London, UK
    Nobody has any real idea. It isn't inflammation, I think we can be sure, because all the body's indicators of inflammation are negative. It has nothing to do with mast cells, I think we can be pretty sure, since it bears no resemblance to mast cell phenomena. Some people with ME, like the rest of the population, may get mast cell activation as part of allergy or non-allergic responses but the only meaningful studies I have seen show no special link between this and ME.

    The only thing that is consistent is that there is a group of physicians who like to build stories about linked illnesses, half of which do not really exist. I have worked closely with these people and my view is they have no understanding how to gather reliable evidence. They are really only concerned with kudos and fees. To put it bluntly I would not pay any attention to doctors who think MCAS is part of the ME/CFS picture. The field is simple, nothing to dissect, - it is 90% bullshit. The bit that matters is just plain old ME.
    Ariel, Invisible Woman, Mij and 6 others like this.
  13. Jonathan Edwards

    Jonathan Edwards Senior Member (Voting Rights)

    London, UK
    And as we see, some patients are very keen to spread the word when it comes to the bullshit.
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  14. Tia

    Tia Senior Member (Voting Rights)

    I asked Dr Bansal (when he was still at St Helier's) about MCAS and he said, 'we don't know if that actually exists'. Given my allergy-like symptoms, he told me that I have irritable mast cells. I think I said they're not just irritable, they're livid (I was having long periods when I couldn't eat anything because of stomach symptoms).

    I never had any allergies before I got ill then I started getting them a few years into becoming ill. Mainly severe hayfever and stomach symptoms. Dr Bansal gave me sodium chromogycate for the the stomach symptoms and it's one of the few medications I've tried that's actually worked.

    Of course, I might have got these allergy symptoms had I not got ME but in my mind (non scientific) I tend to think they're related. I'm happy with the irritable mast cells explanation though and accept not really understanding why.

    I don't feel any need to diagnose myself as having MCAS or to pursue that diagnosis. I'm not sure how it would help me and I've wary of it because:

    Given my own symptoms though, I can completely see why other patients do find it makes sense. As with all of these treatments/theories that gain traction, there is something that resonates, a grain of truth. We just need people who will research it properly rather than trying to become an expert before any research has been done.
  15. lunarainbows

    lunarainbows Senior Member (Voting Rights)

    I agree Tia. I can see also why patients find that it makes sense. I also developed intolerances / allergy symptoms a few years into ME. But they could have developed anyway. I don’t know.

    I think for some ME patients, they get disbelieved by doctors as to their new symptoms, they don’t get any help or treatment & the only doctors they find who believe their new symptoms are the doctors who say they treat MCAS / mast cell problems. Perhaps if all PwME who had allergy type symptoms were treated for those symptoms - MCAS may not have gained traction.

    I think this may be especially true for the stomach related symptoms - as if issues with breathing or anaphylaxis you’d probably be taken more seriously. But stomach symptoms they may write it off as anxiety or IBS or something.. until they find a doctor who says they’ll help. But then again, there’s the issue of is it an intolerance or is it an allergy? Or something else?

    I was thinking about this and the main worries I have around MCAS are:

    ~ it is talked about as if it is established fact. “MCAS occurs as a co morbid condition with ME”. In reality as you’ve pointed out, we know very little about the allergy like symptoms that come about with some people who have ME. We don’t know the prevalence, we don’t know why it occurs or how, what systems it affects, what its actually caused by. Instead a new condition was created, without being able to answer these questions - yet it is given a new name, which very few people or person (Afrin) publish about. Another alarm bell is that Afrin believes mast cells are the underlying issue to many chronic illnesses.

    ~in some places, especially in ME-pedia it lists very wide and varied symptoms, and I’m not sure there’s any proof as to that

    -And even stomach symptoms that might seem consistent. I wrote this on a previous thread, I kept getting misdiagnosed with MCAS for my stomach symptoms, by more than one doctor. Because I had ME and MCAS is supposed to be associated with that. I thought I’ll give it a try, nothing to lose. In the end I ended up wasting quite precious time as my condition got worse. I was also getting dismissed by my GP, I might add. It was only after I insisted on an ultrasound as I felt something else was wrong, that other things were picked up.

    Of course this can happen for any condition, mainstream doctors do this too. but because MCAS is so readily accepted as part of a co morbid “set of conditions” with ME, this happens, even though we don’t know the prevalence of how many of those with stomach pain who have ME, do turn out to have an allergy or mast cell reaction causing that problem.

    I was told by one that my muscle pain was caused by MCAS. I’m pretty sure it’s not. Antihistamines have done nothing for my pain.
    Last edited: Aug 29, 2020
  16. Jonathan Edwards

    Jonathan Edwards Senior Member (Voting Rights)

    London, UK
    The trouble is that if someone were to say that blue eyes go with narrow feet that would resonate with all the people with blue eyes and narrow feet. It would not resonate with people with brown eyes and narrow feet but nobody would notice.

    It may well be that there is an association between ME and various symptoms that are sometimes caused by mast cells (like abdominal pain). But in ME maybe they have nothing to do with mast cells much of the time.

    To me the key thing is what @lunarainbows was saying about symptoms being out down to 'comorbidities' on the basis of rumours between doctors.
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  17. Rhea D.

    Rhea D. Established Member

    Out of curiosity, who is the group of physicians you’re referring to?
    Last edited by a moderator: Sep 1, 2020
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  18. Rhea D.

    Rhea D. Established Member

    I think of these diagnoses as frameworks for classifying and understanding symptoms and *sometimes* etiology—less “real/not real,” more, will this be useful in conveying my illness to doctors, guiding treatment or further research to better understand physiology at work. MCAS and ME together make sense as a framework for the symptoms I developed in 2016:

    • throat swelling and/or urticaria in response to walking/exertion, heat, eating certain foods (mainly fodmaps; tested negative for food allergies), perfume and other chemical scents
    • irritable bladder
    • digestive issues due to SIBO
    • episodes of orthostatic intolerance with pre-syncope and eventually full blown POTS
    • flu-like malaise
    • poor stamina/easy fatigability/PEM
    • Sore throat
    • sinusitis
    • intermittent widespread pain—nerve and muscle, sometimes triggered by what I ate, often triggered by walking
    • insomnia
    • increased sensitivity to light, sounds, smells
    • (ETA) episodic flushing, face and neck
    • (ETA) dermatographia
    • (ETA) spontaneous bruising
    What brought this on was an infectious illness followed by living in a series of water damaged (aka moldy) homes. The Since moving into a mold-free home some of these things have gone away or improved, giving me a better sense of what’s “ME” v. “MCAS,”but I think that, at least in my case, there’s a lot of overlap, and my POTS and MCAS symptoms are definitely intertwined— both triggered by heat and standing/walking. A viral infection in the spring also caused a huge flare in MCAS symptoms, mainly skin.

    The things that trigger my symptoms and the way that they present fit the MCAS paradigm rather than that of allergies. (I did test weakly positive via skin prick for mold allergy, but that wouldn’t explain that wide array of symptoms I developed as a result of living in a moldy home. And prior to this I had zero allergy symptoms.)
    Last edited: Sep 3, 2020
  19. Hutan

    Hutan Moderator Staff Member

    Aotearoa New Zealand
    For new members, just a reminder that if you think a post breaches a rule, you can report it by clicking on the 'contact moderators' below the post.

    Moderators communicate with individual members using the conversation facility - check the 'inbox' at the top right of your screen.
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  20. Jonathan Edwards

    Jonathan Edwards Senior Member (Voting Rights)

    London, UK
    It depends a bit on whether the emphasis is on MCAS or EDS or POTS or whatever but the physicians who appear to me to be uncritical about these so called associations include:

    Dr Peter Rowe
    Dr Rodney Grahame
    Dr Alan Hakim
    Dr William Weir
    Dr Lawrence Afrin
    Dr Olli Polo
    Dr Hans Knoop
    Dr Peter White
    Dr Emma Reinhold
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