I have received 10 infusions of daratumumab and my numbers have radically dropped. My IgG, kappa-lambda ratio, and kappa free light chain level are now in the "normal range". (See my earlier posting with information on my response to daratumumab, "Daratumumab is working for me", Nov 14, 2015.)
However, my cancer center lab cannot accurately measure M-spikes below 1.3. It states, "Concentration of monoclonal protein is too low to accurately quantify." But I'm certain at a different cancer center I was given low readings like 0.3. And when I was in remission six years ago, another lab wrote, "No M-spike has been detected." That sounds like proof to me.
I don't wish to have a bone marrow biopsy just to prove I am in remission. Should I?
Besides, I'll probably receive daratumumab indefinitely whether or not I am in remission.
Also, do labs typically measure M-spikes below 1.0?
Merry Christmas!
Forums
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MikeJBaron - Name: Mike J Baron
- Who do you know with myeloma?: I have myeloma
- When were you/they diagnosed?: 2004
- Age at diagnosis: 56
Re: Measuring M-spikes less than 1.0
Since the last two months, after sixth and seven cycle of Revlimid plus dex, My M-spike is zero - not measurable. But in immunoelectrophoresis, kappa and IgG "suggestive monoclonal gammopathy - positive for IgG and kappa isotopes." My kappa free light chain is 27.1 mg/l (normal range 3.30 - 19.40), my kappa / lambda ratio and lambda is normal. My IgG was little above normal range after five cycles. Bone marrow biopsy was down to five to ten percent. My hematologist says it is not CR and continue Revlimid plus dex chemo one more month.
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MMFeb16,15 - Who do you know with myeloma?: Self
- When were you/they diagnosed?: February 16, 2015
- Age at diagnosis: 66
Re: Measuring M-spikes less than 1.0
Mike,
There actually is a practical "measurable limit" when it comes to quantifying M-spikes. For serum M-spikes, the measurable limit is indeed about 1 g/dL. For a 24 UPEP measuring Bence Jones proteins, the limit is about 200 mg/24 hours. M-spike measurements below these thresholds should therefore be somewhat suspect as far as the actual values are concerned.
https://crawb.crab.org/txwb/CRA_MANUAL/Vol1/chapter%2011c_Response%20Assessment-Myeloma.pdf
But it sounds like you also had a serum immunofixation test, which is more accurate than electrophoresis at detecting the presence of an M-spike - although it won't measure the actual value of the M-spike.
There actually is a practical "measurable limit" when it comes to quantifying M-spikes. For serum M-spikes, the measurable limit is indeed about 1 g/dL. For a 24 UPEP measuring Bence Jones proteins, the limit is about 200 mg/24 hours. M-spike measurements below these thresholds should therefore be somewhat suspect as far as the actual values are concerned.
https://crawb.crab.org/txwb/CRA_MANUAL/Vol1/chapter%2011c_Response%20Assessment-Myeloma.pdf
But it sounds like you also had a serum immunofixation test, which is more accurate than electrophoresis at detecting the presence of an M-spike - although it won't measure the actual value of the M-spike.
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Multibilly - Name: Multibilly
- Who do you know with myeloma?: Me
- When were you/they diagnosed?: Smoldering, Nov, 2012
Re: Measuring M-spikes less than 1.0
First, I am definitely not an expert, and can only try to explain what I understand from my own consultations.
But when my M-spike dropped below the level measured by the standard method, I was told that they then shifted to another method searching for minimal residual disease.
But even though this showed stringent complete remission, they also wanted a bone marrow biopsy. And now after a year with normal results they want another bone marrow biopsy in February. I feel that they are really keeping an eye on me and even though I do of course not long for the next bone marrow biopsy, I am not complaining
Best regards, Lev
But when my M-spike dropped below the level measured by the standard method, I was told that they then shifted to another method searching for minimal residual disease.
But even though this showed stringent complete remission, they also wanted a bone marrow biopsy. And now after a year with normal results they want another bone marrow biopsy in February. I feel that they are really keeping an eye on me and even though I do of course not long for the next bone marrow biopsy, I am not complaining
Best regards, Lev
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Lev - Name: Lev
- Who do you know with myeloma?: Me
- When were you/they diagnosed?: June 2014
- Age at diagnosis: 57
Re: Measuring M-spikes less than 1.0
Lev,
Minimal residual disease (MRD) testing doesn't use any electrophoresis techniques like those used to measure an M-spike. The most common method for MRD testing (and the test that you will likely see coming into more and more labs) is based on multi-color flow cytometry. Basically, MRD testing via flow cytometry looks for aberrant immunophenotypes (i.e. specific antigens on the cell's surface) to detect the presence of myeloma cells.
Minimal residual disease (MRD) testing doesn't use any electrophoresis techniques like those used to measure an M-spike. The most common method for MRD testing (and the test that you will likely see coming into more and more labs) is based on multi-color flow cytometry. Basically, MRD testing via flow cytometry looks for aberrant immunophenotypes (i.e. specific antigens on the cell's surface) to detect the presence of myeloma cells.
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Multibilly - Name: Multibilly
- Who do you know with myeloma?: Me
- When were you/they diagnosed?: Smoldering, Nov, 2012
Re: Measuring M-spikes less than 1.0
Apparently measuring serum M-spikes to an accurate number must be difficult (or impossible). Based on my serum immunotyping electrophoresis it identifies the known monoclonal immunoglobulin but estimates the concentration.
My M-spike has varied from 0.9 g/dl to 0.5 to 0.2 to 0.8 and back to 0.4, always with the statement saying approximately (or essentially unchanged). I would like to think there is a more accurate way of measuring something so important as the M-spike when your treatment often depends on it.
Coach Hoke
My M-spike has varied from 0.9 g/dl to 0.5 to 0.2 to 0.8 and back to 0.4, always with the statement saying approximately (or essentially unchanged). I would like to think there is a more accurate way of measuring something so important as the M-spike when your treatment often depends on it.
Coach Hoke
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coachhoke - Name: coachhoke
- When were you/they diagnosed?: Apri 2012
- Age at diagnosis: 71
Re: Measuring M-spikes less than 1.0
To Multibilly: In my last test at Mayo after five cycle of Revlimid and dex, my M-spike was 1.2 and all my immunofixation of serum test suggested to go for the SPEP test in future. The last two months SPEP test did not show an M-spike reading. My physician said that means no M-spike.
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MMFeb16,15 - Who do you know with myeloma?: Self
- When were you/they diagnosed?: February 16, 2015
- Age at diagnosis: 66
Re: Measuring M-spikes less than 1.0
MMFeb16,
I'm not sure what your question is. But if you wanted to verify if you had any serum monoclonal protein whatsoever, you would still run an SIFE test (which I imagine was still run with your most recent tests since it is usually ordered with an SPEP).
Per the referenced article above:
I'm not sure what your question is. But if you wanted to verify if you had any serum monoclonal protein whatsoever, you would still run an SIFE test (which I imagine was still run with your most recent tests since it is usually ordered with an SPEP).
Per the referenced article above:
In both the serum and urine, the immunofixation tests (SIFE and UIFE) are more sensitive to the presence of M protein than the protein electrophoresis tests (SPEP and UPEP). So sometimes the results from the SPEP or UPEP will indicate that there is no M protein, or that if an M protein is present it is too little to be quantified, but the SIFE or UIFE done on the same sample will indicate that an M protein is present. This is why the response criteria above specify that for a patient to be in a complete response or complete remission, both the protein electrophoresis and the immunofixation tests must be done on the serum and urine, and all tests must be negative for the presence of M protein.
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Multibilly - Name: Multibilly
- Who do you know with myeloma?: Me
- When were you/they diagnosed?: Smoldering, Nov, 2012
Re: Measuring M-spikes less than 1.0
Mulibilly:
Thank you. Now I understand that I am not in CR. I read all information on website suggested by you.
My question same as earlier posted by someone else but not me. In that case, how people are quoting lab test that their M spike went down to 0.5 or 0.2?
Thank you.
Thank you. Now I understand that I am not in CR. I read all information on website suggested by you.
My question same as earlier posted by someone else but not me. In that case, how people are quoting lab test that their M spike went down to 0.5 or 0.2?
Thank you.
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MMFeb16,15 - Who do you know with myeloma?: Self
- When were you/they diagnosed?: February 16, 2015
- Age at diagnosis: 66
Re: Measuring M-spikes less than 1.0
MMFeb16,
Regarding your question
I think the answer is that one should always keep in mind that with an M-spike below 1g/dL that the value is somewhat suspect and that the SPEP test simply isn't accurate to within 0.1 g/dL at those levels.
As the above article states, in the case of an M-spike less than 1 g/dL, one should also be tracking their FLCs for the purpose of monitoring response (which I think you would want to do under any circumstance), provided the involved FLC is large enough.
But, as always, you should verify this with your doctor and remember that this is simply my own interpretation of the above document.
Regarding your question
"In that case, how people are quoting lab test that their M spike went down to 0.5 or 0.2?"
I think the answer is that one should always keep in mind that with an M-spike below 1g/dL that the value is somewhat suspect and that the SPEP test simply isn't accurate to within 0.1 g/dL at those levels.
As the above article states, in the case of an M-spike less than 1 g/dL, one should also be tracking their FLCs for the purpose of monitoring response (which I think you would want to do under any circumstance), provided the involved FLC is large enough.
Patients who have both serum M protein levels < 1 g/dL AND urine M protein levels < 200 mg/24 hrs at baseline may be followed by serum free light chain (FLC) assay if involved free light chain level ≥ 10 mg/dL (≥ 100mg/L).
But, as always, you should verify this with your doctor and remember that this is simply my own interpretation of the above document.
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Multibilly - Name: Multibilly
- Who do you know with myeloma?: Me
- When were you/they diagnosed?: Smoldering, Nov, 2012
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