Invest in ME Conference 12: First Class in Every Way
OverTheHills wraps up our series of articles on this year's 12th Invest in ME International Conference (IIMEC12) in London with some reflections on her experience as a patient attending the conference for the first time.
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Help Interpreting (Validity of) Amino Acid Assay Results

Discussion in 'Diagnostic Guidelines and Laboratory Testing' started by J.G, Sep 2, 2016.

  1. J.G


    Now, I understand that LC:MS amino acid analyses are notoriously unreliable. Despite this, I ordered a 40-item amino acid panel at a local hospital, hoping it would yield (indirect) clues on the state of, i.a., my Trp metabolism, 5HT/DA synthesis, and BCAA availability.

    Yet there's a reliability complication. After gene analysis revealed I'm C665T homozygenous (double mutation), I had two Homocysteine (Hcy) tests done at two different reputable hospitals, one month apart. The results came back as 69.26 and 68.70 umol/l respectively. (Yikes; I've since begun sublingual methylfolate and methylcobalamin supplementation).

    The 40-item amino acid assay (attached) was done concurrently with the second Hcy test at the very same hospital. But guess what - the amino panel gives a value of 2.5 uM (?) for Hcy. Unless I'm terribly wrong, this is a massive discrepancy. I'm tempted to write off the 40-acid panel's results wholesale because of it.

    My questions:
    - I am correct in detecting this discrepancy, and if so, can I set any store by the amino acid results at all?
    - Naively assuming that the panel's other values are indeed correct-ish, does anyone's expert eye detect any obvious anomalies? A whole bunch came back with values of 0,0, which I assume is because of measurement problems. The only non-0 that was outside the normal range is a-ABA.

    Looking forward to your collective insights!

    Last edited: Sep 5, 2016
  2. alicec

    alicec Senior Member

    First check that the tests are measuring the same thing. In the results shown, they are measuring homocystine, not homocysteine.

    Homocystine is the oxidised form of homocysteine (ditto cystine and cysteine).
  3. J.G


    Thanks. The only supporting document I have talks in acronyms, and indicates Cys and Hcys are included in the assay.

    Also, I'm thinking homocysteine is meant, because: 1) of the 0-10 reference range; 2) it seems odd to test homocystine as part of a 40-part amino panel, but not homocysteine; 3) this test was done in Taiwan - excellent medical facilities, but prone to English typo's.

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