There are a lot of symptom similarities b/w MCAS and POTS.
I definitely agree and exercise (in people with MCAS who do
not have POTS, LEMS, ME/CFS, etc, and are able to exercise) can be a HUGE trigger of allergic reactions. In my own case, when my MCAS was incredibly severe with anaphylaxis, I was also very ill in general and used a wheelchair and unable to do any kind of exercise. So I do not know if exercise would have triggered an allergic reaction (b/c it was not even an option for me at that time b/c I couldn't even walk).
My BP is always on the low side and when Im tachycardic it starts to approach 120/80.
My BP has been on the low side life-long and when I developed POTS, it became super low and was approx 80/50 on a daily basis for several years. I don't think I have ever had a BP as high as 120/80 in my life. When I was in the hospital in 2015, my low BP kept triggering alerts for the nurses to check on me but once they knew it was chronically low, they just ignored it.
Whats your normal resting BP/heart rate?
I honestly do not know at this point but I plan to take some new measurements for my doctor and will let you know. I need to Google the NASA Lean test to see what it is (b/c this is one of the things he wants me to try) and also try stairs w/the BP wrist cuff. I have been very fatigued from my Cortef taper (a different issue) and haven't been able to do any of this yet.
Serum (or blood) histamine is actually not a good indicator of mast cell activation because it more reflects histamine contained in basophils. Plasma histamine is more indicative of MC activation. Though still interesting it was 4x higher than upper range of normal and you were asymptomatic, something else mustve been going on.
I may have misspoke and the test may have been plasma histamine. I am going to look for it shortly and come back and add it to this post. I'm sorry it is taking me so long and I have several folders where that test might be from 2014 and am almost 100% certain that it was not lost with all of my pre-2015 papers to the mold.
When you say you never had elevated tryptase are you saying you never had it above the normal range or that it was never elevated from your base tryptase level to your base plus 20% plus 2.
I honestly have no idea. All prior tests just said that Tryptase was in the "normal" range. I don't follow the formula you mentioned re: base tryptase plus 20% plus 2? Would that be something that a lab or doctor would calculate? I have never heard of it before.
I asked once and couldnt get plasmapheresis ;/ may try again when more symptomatic.
I tried to get plasmapheresis for diagnostic purposes in early 2016 after the Mayo Panels showed auto-antibodies but both of my doctors felt it was too dangerous for me. Both of them (independently) felt that high dose IVIG was the right path for me (not plasmapheresis) so that is what I did and they were right. PP is not done very commonly in the US.
Some foods do have a higher chance of stimulating MC degranulation in some. Never looked into what it means to "liberate" histamine.
When I followed the SIGHI Diet (very low histamine diet from Switzerland) in 2015 & 2016, it explained that some foods contained very high histamine vs. other did not actually contain histamine but liberated histamine from the mast cells. I don't know how to explain it beyond that.
If it feels very fragile then why are you extending time b/w infusions? I would extend time if I felt normal or close enough.
I feel like I am not explaining things well and apologize! What I meant by fragile is that we feel that my remission is being maintained by keeping my B cells at zero with Ritux. I wish that we knew that Ritux had permanently "re-set" my immune system so the new B cells will grow back healthy but we have no way to know other than stretching out the interval and praying for the best.
My B cells have been at zero since Aug 2017 and the interval between infusions was 3-months. The last interval was 4-months and this current one will be 5-months. If all goes well, then we will stretch it out to 6-months. But even at 6-months, my doctor said my B cells could still be at zero. So the remission is dependent on the Rituximab and keeping my B cells at zero. My doctor has said it is possible that the B cell programming has changed and new ones will grow back healthy but we just don't know yet.
That is what I meant by fragile but there is no way to ever find out without extending the interval between infusions, and if that goes well, eventually stopping them. If I had ANY return of the severe POTS, muscle weakness, or breathing weakness, I would NOT be stretching out the interval and would accept that I will continue on Ritux for the rest of my life b/c in my former state, I could not stand or walk without wheelchair, could not live independently or take care of my dog. It is worth it's weight in gold to me.
Its all good, Ive been a bit rambly too the past few days.
Thanks and I blame my extra rambliness on this Cortef taper (which I'm talking about in another thread and won't take yours off track
)