I had my 1st 6-monthly check-in with my oncologist this past Thursday after being diagnosed with MGUS on September 1 last year.
He greeted me by saying the M-spike was the same (0.3 mg/dl), but that in fact there may not be an M-spike at all. I didn't get a copy of the report, but the pathology lab had contacted him to say they suspected it was showing an artifact rather than a true reading, and they need to do a highly specific test to double check. I can't recall the name of the test, and the doctor said he had no idea what was involved. I am to return in two months to find out the results.
Has anyone heard of this?
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torifrog - Name: Tori
- Who do you know with myeloma?: Myself - MGUS
- When were you/they diagnosed?: Sept 1 2016
- Age at diagnosis: 51
Re: MGUS as a pathology artifact?
Hi Tori,
Have you had a serum (blood) immunofixation electrophoresis test (sIFE, IFE, or IFX) carried out?
Your serum M-spike is measured by the serum protein electrophoresis (SPEP) test. However, it doesn't tell you what type of monoclonal protein you have (IgG kappa, IgA lambda, etc.,) It is also not particularly sensitive, with a margin of error not much different than your M-spike (0.3 g/dL).
The test that determines what sort of monoclonal protein you have is the serum immunofixation test, and it also is more specifically oriented to detecting whether or not a monoclonal protein is truly present. That's why I ask whether you've had the test done.
That said, the serum immunofixation test is very common, so I am guessing that you have had it done. But you never know.
Have you had a serum (blood) immunofixation electrophoresis test (sIFE, IFE, or IFX) carried out?
Your serum M-spike is measured by the serum protein electrophoresis (SPEP) test. However, it doesn't tell you what type of monoclonal protein you have (IgG kappa, IgA lambda, etc.,) It is also not particularly sensitive, with a margin of error not much different than your M-spike (0.3 g/dL).
The test that determines what sort of monoclonal protein you have is the serum immunofixation test, and it also is more specifically oriented to detecting whether or not a monoclonal protein is truly present. That's why I ask whether you've had the test done.
That said, the serum immunofixation test is very common, so I am guessing that you have had it done. But you never know.
Re: MGUS as a pathology artifact?
Hi Tori,
I think Terry is right. Questionable m-spikes are usually "reflexed" (passed on) to immunofixation testing to verify if the spike is truly monoclonal or not.
This is an article that may describe your situation:
Katzmann, JA, et al, "Specificity of Serum and Urine Protein Electrophoresis for the Diagnosis of Monoclonal Gammopathies," Clinical Chemistry, Dec 2010 (full text of article)
If you have already had a serum immunofixation test, then I'm not quite sure what additional tests can be done.
I think Terry is right. Questionable m-spikes are usually "reflexed" (passed on) to immunofixation testing to verify if the spike is truly monoclonal or not.
This is an article that may describe your situation:
Katzmann, JA, et al, "Specificity of Serum and Urine Protein Electrophoresis for the Diagnosis of Monoclonal Gammopathies," Clinical Chemistry, Dec 2010 (full text of article)
If you have already had a serum immunofixation test, then I'm not quite sure what additional tests can be done.
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Multibilly - Name: Multibilly
- Who do you know with myeloma?: Me
- When were you/they diagnosed?: Smoldering, Nov, 2012
Re: MGUS as a pathology artifact?
Yes, all of that was done 6 months ago. I have an earlier post here with those results:
https://myelomabeacon.org/forum/diagnosed-with-mgus-confused-by-lab-results-t7734.html
Suffice to say I was diagnosed as IgM kappa.
The possible anomaly was picked up this time round as a false positive or artifact. The doctor did tell me the test the pathologists will be running, but I simply can't recall it. I know it had "auto" in it somewhere, which is no use at all. I'm guessing I have some kind of antibody or other weirdness that leads to this possibly false reading in me. Then again, it may not be false at all! I'll find out at that next appointment.
So I'm gathering no one here has experienced this particular situation previously.
https://myelomabeacon.org/forum/diagnosed-with-mgus-confused-by-lab-results-t7734.html
Suffice to say I was diagnosed as IgM kappa.
The possible anomaly was picked up this time round as a false positive or artifact. The doctor did tell me the test the pathologists will be running, but I simply can't recall it. I know it had "auto" in it somewhere, which is no use at all. I'm guessing I have some kind of antibody or other weirdness that leads to this possibly false reading in me. Then again, it may not be false at all! I'll find out at that next appointment.
So I'm gathering no one here has experienced this particular situation previously.
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torifrog - Name: Tori
- Who do you know with myeloma?: Myself - MGUS
- When were you/they diagnosed?: Sept 1 2016
- Age at diagnosis: 51
4 posts
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