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Old 03-02-2020, 01:13 PM
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janieg janieg is offline
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Join Date: Jan 2014
Location: Maryland
Posts: 792
10 yr Member
janieg janieg is offline
Member
janieg's Avatar
 
Join Date: Jan 2014
Location: Maryland
Posts: 792
10 yr Member
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I want to post this information here in case it should ever help anyone.

From Histamine - Wikipedia

"Once formed, histamine is either stored or rapidly inactivated by its primary degradative enzymes, histamine-N-methyltransferase(HNMT) or diamine oxidase(DAO). In the central nervous system, histamine released into the synapses is primarily broken down by histamine-N-methyltransferase, while in other tissues both enzymes may play a role. Several other enzymes, including MAO-B and ALDH2, further process the immediate metabolites of histamine for excretion or recycling."

I believe low levels of HNMT is a contributing factor in my neuropathy. DAO supplements don't appear to help at all. These two SNPs on the HNMT gene have been documented as resulting in reduced levels of HNMT, and thus a reduced ability of breaking down of histamine that could impact proper functioning of the CNS:

rs1050891 - A/A is normal, I'm A/G
rs11558538 - CC is normal, I'm C/T (C314T Thr105Ile)

Both are tested on 23andme, although the second isn't available by SNP name. (Ping me for more information.)

The immunologist who diagnosed currently has me on Zyrtec once a day and 40 mg of famotidine (Pepcid AC) twice a day to try to get my histamine levels down. My plasma histamine level was high in the blood test he ran.

I'm also on a low histamine diet which has helped bring them down as well. one or both actions has pulled me out of a terrible flare I was in caused by three consectutive days on high histamine food consumption. It was so bad that I actually did have a classic allergic reaction. That's what caused me to make an appointment with an allergist/immunologist. I knew it had to be a clue.

I was very fortunate that this doc whose office is two miles from my house is well-versed in Histamine Intolerance and Mast Cell Activiation problems. Not all are.
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Lara (08-23-2021)