MGUS & Mastocytosis

[jenniferBSc]

Hi anyone else had an abnormal paraprotein identified? I have IgA kappa discovered after a myeloma screen I also have an enlarged spleen, unfortunately a BMB came back from the lab as an insufficient sample, so may have to be repeated. Another question for Jess can MCAS change to Mastocytosis over time? TIA

[Jess-UKMasto Partner]

Hi Jennifer, that isn't a test that I commonly hear comes up positive in mastocytosis. We do know that mastocytosis can be accompanied by other haematologic neoplasms that are either from the myeloid line (more common) or lymphoid (less common). It sounds like it would be good to be seen by a haematologist with extensive experience with mastocytosis if that's a likely part of the story, and collaborating with someone who is expert in myeloma as well just to be sure that your diagnosis is really clear. (If you pm me we can think about the UK folks we know about, assuming you're here in the UK.) Regarding MCAS... MCAS is really a diagnosis of exclusion-- meaning the symptoms are looked at and the tests are done showing an increase in mast cell mediators and mastocytosis is ruled out (along with any other explanations for why you have the symptoms and the test results you have). So you can have a diagnosis of MCAS (because mastocytosis wasn't proven) and then have the mastocytosis be found (that was likely there all along). Until we understand the underlying mechanism for MCAS and have a test to see if that mechanism is present, MCAS is likely to continue to be a diagnosis you get by excluding other explanations and having some tests that would also be positive in mastocytosis (serum tryptase, urinary metabolites of histamine and prostanglandinD2). I hope that makes sense, but I can explain more if needed.

[jenniferBSc in reply to Jess-UKMasto]

Thanks Jess yes it makes absolute sense. I’m not sure how to DM you here but just to fill in a gap or two, I have been seen by a great haematology team here in Plymouth unfortunately a BMB result came back as an insufficient sample so nothing definitive regarding mastocytosis and other conditions at present, Covid has delayed all diagnostics of course but they are hoping to combine with the immunology team to see a way forward for me, all of the MCAS treatments I’ve tried so far seem to be a temporary fix at best, there seem to be very few gaps between flares now, hoping for more treatment options in the not too distant future, thanks so much for responding it’s very much appreciated

[Jess-UKMasto Partner in reply to jenniferBSc]

Plymouth has folks with an interest in mastocytosis, so that sounds like a good place to be. I'm sorry about the BMB that didn't get the information you need. That's really rubbish. And I sent you a pm in case you do want to write. You would click on my name, and then poke the message button.

[MadRed13]

Hi Jennifer, I have SM and have just been diagnosed with MGUS. I have no more details as yet.

[jenniferBSc in reply to MadRed13]

Hi thanks for responding, it’s always reassuring when we aren’t alone, take care

[MadRed13 in reply to jenniferBSc]

Thanks Jennifer, it was found when I had a recent bone marrow biopsy to check progress of my ISM. Just another thing to add to my growing list of conditions. Trying to get it into perspective and not worry. It will be monitored from now on alongside the rest, so the biopsy sort of did me a favour.

[jenniferBSc in reply to MadRed13]

I’m in a similar place and understand completely, hoping my recent BMB ensures both clarity and treatment options