[gardengirl]

IgA and M-spike

by gardengirl on Mon Dec 15, 2014 2:25 pm

Hello! I have a few questions regarding IgA and m-spike:

1. As I understand it, the M-spike reflects the amount of abnormal protein, but this can be inaccurate in IgA multiple myeloma because of "co-migration of monoclonal IgA with other proteins". Can someone explain what that means? How do you know if co-migration is occurring?
2. Does this mean the M-spike is underestimated for IgA? For example, if my IgA is 1600 mg/dL, and the m-spike (only band detected) is 0.6 g/dL, then that means the amount of "normal" IgA should be 1600-600 = 1000 mg/dL (which is still high and out of range of normal 90-400, so is therefore inaccurate?)
3. Is it safe to say that if IgA falls into the normal range during treatment that there is no m-spike?
4. Since response to treatment includes evaluating the m-spike, how is this done with IgA multiple myeloma?
5. Thoughts on Heavylite Assay? Should I request this test?

I guess that's more than "a few," but any input is greatly appreciated!

Thank you!!!!

[BeatMyeloma]

Re: IgA and M-spike

by BeatMyeloma on Mon Dec 15, 2014 3:05 pm

Hi gardengirl,

I am so not an expert, but my mother has IgA-type myeloma. According to her doctor, she does not have a M spike. Apparently, that's not uncommon with IgA myeloma. For Mom, the IgA number is the marker they keep an eye on.

[Multibilly]

Re: IgA and M-spike

by Multibilly on Mon Dec 15, 2014 4:12 pm

Hi Gardengirl,

The SPEP can indeed mis-report the M-Spike for an IgA-type multiple myeloma patient.

I really don't think that a doc can ever quite assume that your M-Spike is truly zero with IgA multiple myeloma, even though it might very well be. I say this because I would think that you could have a small amount of monoclonal protein in your blood and still have your quantitative IgA fall within a normal range and your SPEP M-spike could erroneously read zero. But I'm not a doc, so I can't claim this with certainty.

The Hevylite Assay would be a great way to track your IgA disease. But I think your challenge will be finding a lab that is set up to do this brand new test. So you might just have to rely on the quantitative IgA lab and all your other labs, such as the free light chain assay, to help figure this out the best you can.

Last edited by Multibilly on Mon Dec 15, 2014 5:32 pm, edited 1 time in total.

[Wayne K]

Re: IgA and M-spike

by Wayne K on Mon Dec 15, 2014 5:20 pm

I know it can get confusing. My M spike is now 190, but my IgG, IgA, and my IgM are all well below normal.

[mrozdav]

Re: IgA and M-spike

by mrozdav on Mon Dec 15, 2014 5:56 pm

Hello. Having tried to post a response a while ago, I will try again. I am glad that you asked these questions because I have been having similar questions.

My M-spike at last testing was 0.25 and my IgA was 311. My doctor indicated that she would rely more on the IgA figure than the M-spike, but did not give an explanation. She also said that it was not correct to subtract, in my context, the M-spike from the total IgA, that is not how it is done. Again, no explanation. So, I am hoping that someone on the forum will attempt to explain.

[Multibilly]

Re: IgA and M-spike

by Multibilly on Mon Dec 15, 2014 6:58 pm

mrozdav,

The following is what my hematologist told me in one of my first meetings. For my myeloma (IgG type), all all one has to do to calculate the non-tumor (i.e. normal or healthy) immuno­globulin level, is to indeed subtract the M-Spike (which measures the abnormal, involved immuno­globulin level) from the quantitative involved immunoglobulin level (which is the sum of healthy and abnormal involved immuno­globulins). Put simply: (Healthy IgG level) = (Total Quantitative IgG) - (Mspike). At least, that is what I recall him telling me.

BUT, with IgA-type multiple myeloma, this formula may not work very accurately since other kinds of proteins may occupy the same place on the SPEP graph where the IgA M-Spike is found (see video I posted earlier in this thread). The fact that other proteins can live in the same area of the graph as the IgA M-spike makes the measurement of the IgA M-spike suspect and inaccurate on an SPEP.

[Dr. Jonathan Kaufman]

Re: IgA and M-spike

by Dr. Jonathan Kaufman on Tue Dec 16, 2014 8:48 am

Gardengirl, I'll try to answer your questions here:

As I understand it, the M-spike reflects the amount of abnormal protein, but this can be inaccurate in IgA multiple myeloma because of "co-migration of monoclonal IgA with other proteins". Can someone explain what that means?

Multibilly has done a nice job of explaining. The serum protein electrophoresis (SPEP) is a test that assesses the proteins in your blood (serum). The IgA M-spike (m protein, mono­clonal protein, paraprotein) falls in a region of the SPEP where there are many other normal proteins. The test requires an interpretation by a pathologist who then reports the amount of protein in the region where the original M spike was. The test cannot differ­entiate between normal and abnormal.

The total IgA measurement is calculated using a different test which is specific and does not require an interpretation by the pathologist. The total amount of IgA will be a combination of abnormal IgA as well as normal IgA. One other note. If the immuno­fix­ation is negative (normal) then all of the IgA reported will also be normal.

How do you know if co-migration is occurring?

The SPEP report should comment that the IgA is "co-migrating" with other proteins in the beta region.

Does this mean the M-spike is underestimated for IgA? For example, if my IgA is 1600 mg/dL, and the m-spike (only band detected) is 0.6 g/dL, then that means the amount of "normal" IgA should be 1600-600 = 1000 mg/dL (which is still high and out of range of normal 90-400, so is therefore inaccurate?)

Yes, the M-spike on the SPEP will often underestimate the actual value. And the total IgA can overestimate.

Is it safe to say that if IgA falls into the normal range during treatment that there is no m-spike?

Not necessarily. A small M-spike can still be within the normal range of the IgA. The immuno­fix­a­tion will let you know if there is any M-spike at all.

I hope this helps,

Jlk

[gardengirl]

Re: IgA and M-spike

by gardengirl on Wed Dec 17, 2014 2:30 am

Thank you Dr. Kaufman and all for your responses! IgA is tricky and I'm trying to learn a little more each day. Knowledge is power! Multibilly, I knew I could count on you for a helpful link!

[wesley]

Re: IgA and M-spike

by wesley on Wed Dec 17, 2014 2:35 pm

Greetings:

I am still a bit confused. I was diagnosed in July, 2013 and had and ASCT in February of this year at Mayo Rochester. I have bi-monthly bloodwork at my local cancer center. My local doc is a general oncologist, not a hematologist or multiple myeloma specialist. Every other month, I get from him an IgA level and an M-spike. I am on Revlimid maintenance (10 mg). I have virtually no contact with my Mayo specialist, mainly because I feel fine and have no issues with Revlimid or multiple myeloma in general.

I work as a college prof, and I am scheduled for an 18-day trip to Turkey next August!

I tend to have an M-spike of 0.1 g/dL or so, and normal IgA WNL (within normal limits).

Questions:

The doctor in this thread noted that M-spike is a combo of m protein, mono­clonal protein, and paraprotein for those of us with IgA. So a basic question: What does the "M" in M-protein stand for. I thought it was "monoclonal"??

Also, I get my SPEP results every other month (IgA level and M spike), but my local doc never mentions IFE, although I think it is being done. How would the results of IFE be reported to me? No monoclonal protein present? No M-spike present? Some other wording?

I understand "in theory" that IFE detects protein as "present or not present", but does not quantify it. If I have an M spike of 0.1 g/dL, why would IFE even be needed? I obviously have M protein present if it is measurable on SPEP, even as low as 0.1.

In sum, what results should I be asking my local doc for other than M-spike and IgA level, and how will results be "phrased".

Thanks

PS Local doc always gives me M-spike and IFE verbally. I write them down and later enter the values into my trusty Excel spreadsheet of test results, which I have maintained since diag­nosis. I guess the "take home" here is to ask for an actual printout, like I got from Mayo at the 100 day check.

Thanks for any feedback you can offer,
Wesley

[Multibilly]

Re: IgA and M-spike

by Multibilly on Wed Dec 17, 2014 3:46 pm

Wesley,

I think you misunderstood Dr. K. He is not saying that the "M-spike is a combo of m protein, mono­clonal protein, and paraprotein for those of us with IgA". He simply gave a list of alternative names for the same thing. M-spike = M-protein = Paraprotein = Monoclonal Protein. They all mean the same thing.

An IFE is more sensitive than an SPEP at detecting the presence and type of monoclonal protein (IgG lambda, IgA lambda, etc), but it won't tell you the amount of the monoclonal protein ... as you pointed out. So, the value of an IFE is more around it providing a definitive indication if there is monoclonal protein present or not (which an SPEP could misrepresent). Once you know your type of multiple myeloma from your initial IFE, follow-up IFEs can also still be useful if you develop two different kinds of M-spikes (biclonal gammopathy) or if a different kind of M-spike appears after treatment.