Mast Cell Activation May Underlie Chronic Fatigue Syndrome — Medscape

SALT LAKE CITY, UT — Mast cell activation syndrome (MCAS) may be an overlooked yet potentially treatable contributor to the symptoms of chronic fatigue syndrome/myalgic encephalomyelitis (ME/CFS), say physicians who specialize in ME/CFS and its manifestations.

The subject was discussed during a 2-day clinician summit held March 2 to 3, 2018, during which 13 panelists met to begin developing expert consensus guidance for primary care and specialist physicians for the management of the complex multisystem illness ME/CFS, and to recommend research priorities.

“ME/CFS is a descriptive diagnosis of a bunch of symptoms, but it says nothing about what’s causing the symptoms, which is probably part of the reason it’s so hard for it to get recognition. So, the question becomes, What other pathology is driving this illness and making the person feel so ill? I think mast cell activation is one of those drivers, whether cause, effect, or perpetuator, I don’t know,” internist David Kaufman, MD, who practices in Mountain View, California, told Medscape Medical News.

MCAS is a recently described collection of signs and symptoms involving several different organ systems, that, as with ME/CFS itself, do not typically cause abnormalities in routine laboratory or radiologic testing. Proposed diagnostic criteria were published in 2010 in the Journal of Allergy and Clinical Immunology.

Kaufman first learned about MCAS about 5 years ago from a patient who introduced him to the published work of mast cell expert Lawrence Afrin, MD. “I spoke to him and then I started looking for it, and the more I looked, the more I found it,” Kaufman said, estimating that he has identified MCAS in roughly half his patients who meet ME/CFS criteria.

Indeed, summit panel member Charles W. Lapp, MD, who recently retired from his ME/CFS and fibromyalgia practice in Charlotte, North Carolina, told Medscape Medical News, “I see a lot of this. I think it’s one of the many overlap syndromes that we’ve been missing for years.”

Another panel member, New York City ME/CFS specialist Susan M. Levine, MD, also said she sees MCAS frequently. “I suspect 50% to 60% of ME/CFS patients have it. It’s a very new concept.”

In Levine’s experience, MCAS often manifests in patients being unable to tolerate certain foods or medications. “If we can reduce the mast cell problem, we can facilitate taking other drugs to treat ME/CFS,” she said. However, she also cautioned, “It’s going to be a subset, not all ME/CFS patients.”

Clinical Assessment and Laboratory Testing

As discussed at the summit, for patients who meet ME/CFS criteria, the next step is to drill down into individual patients’ symptoms and address treatable abnormalities. Investigation for MCAS may yield such findings among those who exhibit episodic symptoms consistent with mast cell mediator release affecting two or more of the following areas:

  • Skin: urticaria, angioedema, flushing
  • Gastrointestinal: nausea, vomiting, diarrhea, abdominal cramping
  • Cardiovascular: hypotensive syncope or near syncope, tachycardia
  • Respiratory: wheezing
  • Naso-ocular: conjunctival injection, pruritus, nasal stuffiness

Symptoms can wax and wane over years and range from mild to severe/debilitating. It is important to ask about triggers, Kaufman advised. “The patient is usually aware of what makes them feel worse.”

Routine laboratory assessments include complete blood count with differential, complete metabolic panel, magnesium, and prothrombin time/partial thromboplastin time.

More specific laboratory testing can be tricky, as the samples must be kept cold. These include serum tryptase, chromogranin A, plasma prostaglandin D2, histamine, heparin, a variety of random and 24-hour urinary prostaglandins, and urinary leukotriene E4.

For patients who have had a prior biopsy, the saved sample can be stained for mast cells.

Kaufman said that initially after he learned about MCAS, he would only run the laboratory tests in patients with suggestive clinical history, such as food sensitivities/triggers, rashes, hives, temperature intolerance, or chemical sensitivities. “But ultimately, I had patients [for whom] I couldn’t figure out what was going on; I would check, and started finding positives in patients I wasn’t suspicious of.”

So, now he just tests for it in all his patients with ME/CFS. “It’s bigger than allergy,” he remarked.

Treatment May Ease Some ME/CFS Symptoms

Treatment of MCAS involves trigger avoidance as possible; H1 receptor antagonists such as loratadine, cetirizine, or fexofenadine (up to double the usual doses); H2 histamine receptor antagonists including famotidine or ranitidine; and mast cell membrane-stabilizers such as cromolyn sodium. Slow-release vitamin C can also help in inhibiting mast cells.

Over-the-counter plant flavonoids such as quercetin also may be helpful, typically at high doses (up to 1000 mg three times daily). “There’s a long list of medications that either quiet down mast cell activation or block the receptor,” Kaufman noted.

But despite that, without controlled trials, it is difficult to determine the exact clinical effects of blocking mast cells, especially as these patients tend to be taking many other medications. And in the context of ME/CFS, the extent to which suppressing mast cell activity addresses the core symptoms of fatigue, postexertional malaise, orthostatic intolerance, and cognitive dysfunction is unclear.

Kaufman noted, “I think treatment clearly helps with the fatigue because they’re not reacting to everything. It improves gastrointestinal symptoms, so they can eat better…. I have seen [postural orthostatic tachycardia syndrome] improve, but I have to say I also give meds for dysautonomia, so I can’t be sure.”

Lapp said that in his experience, “[Patients with ME/CFS] aren’t cured, but do get better. [Blocking mast cell activity] gets rid of dizziness, fatigue, nausea, and light sensitivity.”

Levine pointed out, “We’re just at the beginning of identifying this patient subset and thinking what makes sense to try…. One thing that’s sure is that the drugs are pretty safe,” she said, adding that when it comes to working up patients with ME/CFS for MCAS, “There only seem to be good things that can happen.”

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Long Overdue Update

I think it’s time to write an update. I haven’t wanted to neglect my blog — in fact, I wake up daily thinking about things I’d like to document and share — but I’ve somehow been very busy for what feels like years. My energy is still so limited and, with each incremental increase in functioning, I want to take some of the burden off my husband by cooking my own food, getting myself to appointments or taking care of our dog. It leaves no space for writing. I hesitate to say “no time for writing” because, even as a sick person — even as the person in question — I think, “you have nothing but time!” But I don’t, my window of functionality is still so small. There were months in the past when I worked 70 hours a week and I somehow still had the time to accomplish more than I do now — because my internal engine worked efficiently and my tank held much more gas and was easily refilled overnight. I can imagine my healthy friends reading this and wondering how someone with no job, no kids and no social engagements can possibly feel like they don’t have time to write an update. Maybe, if I manage to complete this blog post, it’ll be clearer.

These last few years, I have put great effort into trying to be an easier human to be around, trying to act like my old self for my husband and when I see people — you know, trying to be one of those “it’s great the way she stays positive and keeps fighting while dealing with such suffering” kind of people. But when you only post the good moments on Facebook and you draw from deep reserves while talking to people to appear perky and mildly engaging, it can cause… confusion, for lack of a better word. Even my closest friends and family obviously can’t see on the outside of me what I assume must be alarmingly salient and sometimes I get concerned that maybe, deep down, they think I’m just living the good life while my husband slogs away at his very physically-demanding job. They have made comments that make me think I’ve never done a good job of explaining this disease and, in fact, sometimes their loving and well-meaning encouragement sounds like they think I need the courage to get out into the world.

There are certain things that take courage in my life– they are all mast cell threats. It takes courage for me to go to places where there are no easily-accessible emergency rooms, like Vashon Island, where our friends live, or in an airplane. It takes courage to try a new medication, knowing I could have a reaction. My experiences with full-blown anaphylaxis and nocturnal mast cell meltdowns have made me fearful of a lot in life — not only of things I’ve reacted to, but typical triggers that have never caused me problems because I always wonder if they’re filling my “bucket” and the reaction is looming behind a blind bend in the road. For example, I may think I can eat just about anything and I love hot weather, but most mast cell patients can’t and don’t. So, maybe a few family members come over on the 4th of July and my period is due (“events” can cause reactions for me, as does menstruation). I’m basking in the sun and I’ve eaten a banana, some cheese, some chocolate that day (typical foods that cause reactions for others). Then the fireworks start and my dogs go into paroxysms of panic, which causes me distress (emotions can degranulate mast cells) and, just like that, the bucket overflows and my tongue swells up and I’m in for a very scary, sleepless night. I think it’s just from hormones and excitement, but maybe without the sunbathing or the chocolate, it wouldn’t have happened, who knows? I’ve been blindsided by this sort of thing too often and it seems, no matter how much time goes by, there will always be a tad bit of trepidation lurking in the back of my mind when navigating the minefield of mast cell degranulation.

So, some things do take courage, yes, but living, doing, experiencing, independence — all the things that ME/cfs took from me — they take no courage at all, they just need a functioning body. My greatest desire is to be traveling or socialising or hiking with my dog. If I was suddenly healed tomorrow, all of your phones would be ringing off their hooks and I’d be asking to crash on your couches as I hopped from Seattle to Oregon to California to Wisconsin to Tennessee to New York to Connecticut to Ireland to England to Germany and hugged you all close and talked your ears off for months on end. If anything, I need to be urged to pull back and conserve my energy because I am my own worst enemy, suffering payback on a daily basis from some reckless endeavor like cutting a thick-skinned squash or shaving my legs. Yesterday, I took Riley and my sister-in-law’s dog on a walk, using my mobility scooter. When I used to take Bowie out, it took very little strength and energy: He could be off-leash, I’d sit on the scooter and watch him eat grass or motor beside him as he ambled along. But these two pups are runners, pullers, criss-crossers and leash-tanglers. Not only did our hour walk sap the majority of my energy yesterday, today I am in pain from head to coccyx from using muscles that I usually don’t. But it brings me such joy, of course, so I’ll do it again.

For about four months this year — mid-April to mid-August — I was probably better than I’ve been since getting sick. But, when my Mum visited last March she said it was the sickest she’d ever seen me. It wasn’t — I think she has forgotten some of the horrors of the early years — but that illustrates just how changeable my health can be in a 6-month period. In general, if I keep my activity steady, I can predict how my days will go. That doesn’t mean I can control how severe my symptoms are, it just means that the worse I get, the less I do each day and vice versa and, if I’m careful, this will usually even out to a higher or lower baseline. In the beginning of my chronic illness, the freefall didn’t slow until I stopped working, then stopped going out of the house and eventually spent most of my time in bed. Slowly, slowly thereafter, my days became more predictable and then, even slower than that, my limits expanded, millimeter by millimeter.

Besides managing my activity, I think the only other thing that has contributed to my improvements are immunoglobulin infusions, which I’ve been doing for three years. But, like I said, I was much sicker last winter while still doing infusions, so you can always assume that those two steps forward will be followed by one step back. Just as long as there is a net profit at the end of the year, I’m content. Not happy or at peace, but I’ll take it.

Anyway, on to the actual update. But I’m wiped now, so to be continued…