Hi all,
I was diagnosed with light chain MGUS about 2 years ago due to an elevated kappa free light chain blood test and an elevated kappa-lambda ratio. I have been being followed by specialists at the cancer center near where I live.
At first I had repeat testing at 3 months then was allowed to go 6 months when those tests continued to show only elevated kappa free light chains and ratio. I never showed an M-spike in any testing, and my initial bone marrow biopsy only showed a 1% plasma cell finding. For that reason, my hematologist only required that I have yearly testing after that.
When I went for annual testing in December my kappa free light chain level and kappa-lambda ratio had risen slightly to 44.77 mg/L and a ratio of 3.15, and for the first time I had a detectable M spike of 0.3 g/dL (3 g/l) on the SPEP test as well as an elevated SPE Alpha 2 and an elevated SPE gamma. The diagnosis is now listed as IgG kappa monoclonal gammopathy.
The hematologist office said I could no longer have annual testing because of this change and would need to have repeat testing in 90 days and that if my levels continued to increase I would have to have a repeat bone marrow biopsy and a PET scan. I go back on March 14th for testing and I am dreading it.
Is it unusual for someone with an initial diagnosis of light chain only MGUS to later develop a detectable M-spike?
I can't find much info on this type of scenario and wondered if it's unusual.
Forums
7 posts
• Page 1 of 1
Re: Can light chain MGUS become "normal" MGUS?
Hi IndianaMom,
I'm wondering if what you're seeing is just the result of your MGUS becoming a bit more extensive in your body. In other words, the monoclonal plasma cells in your body may always have been producing monoclonal IgG as well as monoclonal kappa free light chains. But, until now, the amount of monoclonal IgG has been small enough that it hasn't been picked up as an M-spike on your SPEP.
If you go back to some of your older lab results, where you didn't have an M-spike, do you have any serum immunofixation results and, if so, did they by any chance say that they found IgG kappa monoclonal protein in your blood?
It's certainly possible that your MGUS has changed from being light-chain to "regular" MGUS. However, I think it's more likely that it's just become a bit more extensive, and it's just now that you're seeing the M-spike part of it.
I'm wondering if what you're seeing is just the result of your MGUS becoming a bit more extensive in your body. In other words, the monoclonal plasma cells in your body may always have been producing monoclonal IgG as well as monoclonal kappa free light chains. But, until now, the amount of monoclonal IgG has been small enough that it hasn't been picked up as an M-spike on your SPEP.
If you go back to some of your older lab results, where you didn't have an M-spike, do you have any serum immunofixation results and, if so, did they by any chance say that they found IgG kappa monoclonal protein in your blood?
It's certainly possible that your MGUS has changed from being light-chain to "regular" MGUS. However, I think it's more likely that it's just become a bit more extensive, and it's just now that you're seeing the M-spike part of it.
Re: Can light chain MGUS become "normal" MGUS?
Thank you for responding. 
I have reviewed 5 sets of previous labs over the past 2 years, and the only abnormal findings have been elevated kappa free light chain levels and kappa-lambda ratio, which have steadily gone up by a few points over the past 2 years, but no major increases. I had been told by the myeloma specialist that I had light chain MGUS that appeared stable and I could now be followed yearly. After my bloodwork in December, the nurse from the cancer center called to say I couldn't go a year in between appointments and I would need to re-test in 90 days due to the new finding of the M-spike.
I return to the cancer center in a week to have that testing and at that time will get to speak to the myeloma specialist about my results and plan to ask him about the new diagnosis on my labwork of IgG kappa monoclonal gammopathy. I am nervous to have this testing, especially since the nurse said I would probably be having another bone marrow biopsy and PET scan if my numbers were higher.
I'm also wondering how common it is to have something happen like happened with me (light chain MGUS becoming MGUS with both an M-spike and elevated free light chain level / ratio).
I will let you know what the hematologist says about the new detection of the M-spike.
I have reviewed 5 sets of previous labs over the past 2 years, and the only abnormal findings have been elevated kappa free light chain levels and kappa-lambda ratio, which have steadily gone up by a few points over the past 2 years, but no major increases. I had been told by the myeloma specialist that I had light chain MGUS that appeared stable and I could now be followed yearly. After my bloodwork in December, the nurse from the cancer center called to say I couldn't go a year in between appointments and I would need to re-test in 90 days due to the new finding of the M-spike.
I return to the cancer center in a week to have that testing and at that time will get to speak to the myeloma specialist about my results and plan to ask him about the new diagnosis on my labwork of IgG kappa monoclonal gammopathy. I am nervous to have this testing, especially since the nurse said I would probably be having another bone marrow biopsy and PET scan if my numbers were higher.
I'm also wondering how common it is to have something happen like happened with me (light chain MGUS becoming MGUS with both an M-spike and elevated free light chain level / ratio).
I will let you know what the hematologist says about the new detection of the M-spike.
Re: Can light chain MGUS become "normal" MGUS?
Hello again,
If your serum immunofixation test results did not show any sort of monoclonal protein at all up until now, then you really have no way of knowing whether there has been any change in your MGUS.
I am not even sure how your doctor knew for certain that the cause of your elevated kappa-lambda ratio was due to MGUS if the immunofixation test was clean. The immunofixation test reports the presence of any monoclonal immunoglobulins (IgA, IgG, IgM, etc) it finds and the presence of any monoclonal free light chains it finds (kappa or lambda). If it didn't report the presence of any monoclonal kappa free light chains, how did your doctor know for sure that MGUS is the cause of your elevated kappa-lambda ratio?
Keep in mind that the serum immunofixation test (IFE, or sometimes IFX) is not the same as the serum protein electrophoresis (SPEP) test. They are two different tests.
The SPEP gives you an estimate of what your M-spike is.
The immunofixation test tells you whether the M-spike is IgA, IgG, or IgM, and it also tells you whether you have kappa or lambda monoclonal free light chains.
I still think the most likely explanation is simply that your MGUS has been at such a low level until now that the monoclonal plasma cells you've had were not producing enough monoclonal IgG to be measured on your SPEP test.
In any case, let us know what you find out. Good luck!
If your serum immunofixation test results did not show any sort of monoclonal protein at all up until now, then you really have no way of knowing whether there has been any change in your MGUS.
I am not even sure how your doctor knew for certain that the cause of your elevated kappa-lambda ratio was due to MGUS if the immunofixation test was clean. The immunofixation test reports the presence of any monoclonal immunoglobulins (IgA, IgG, IgM, etc) it finds and the presence of any monoclonal free light chains it finds (kappa or lambda). If it didn't report the presence of any monoclonal kappa free light chains, how did your doctor know for sure that MGUS is the cause of your elevated kappa-lambda ratio?
Keep in mind that the serum immunofixation test (IFE, or sometimes IFX) is not the same as the serum protein electrophoresis (SPEP) test. They are two different tests.
The SPEP gives you an estimate of what your M-spike is.
The immunofixation test tells you whether the M-spike is IgA, IgG, or IgM, and it also tells you whether you have kappa or lambda monoclonal free light chains.
I still think the most likely explanation is simply that your MGUS has been at such a low level until now that the monoclonal plasma cells you've had were not producing enough monoclonal IgG to be measured on your SPEP test.
In any case, let us know what you find out. Good luck!
Re: Can light chain MGUS become "normal" MGUS?
I went today for repeat testing and while I don't have results yet, I wanted to update information for the previous serum immunofixation electrophoresis (IFE) serum testing that Cheryl G had asked about. I wasn't able to view these results online and could only see previous free light chain assays and serum protein electrophoresis (SPEP) results for some reason.
Today I was given my results for the last 2 serum IFEs:
December 2016:
December 2017:
My diagnosis is now listed as IgG kappa monoclonal gammopathy.
My doctor said that it is difficult to say if the MGUS has truly changed from light chain MGUS to IgG kappa MGUS or if the IgG monoclonal protein already was present in my body before and has now progressed to levels high enough to be detected by the SPEP. He said once he receives the results from today he will be able to tell if the previous jump in my levels was a one-time occurrence or if they are trending up to the point where I need to have another bone marrow biopsy and PET scan.
So I guess I probably won't ever know if I really was light chain MGUS and it changed or if I was mislabeled due to the protein not being able to be detected previously.
Today I was given my results for the last 2 serum IFEs:
December 2016:
- IFE serum interpretation: serum immunofixation reveals a faint kappa light chain monoclonal protein band
- SPE interpretation: normal serum protein electrophoresis pattern*
December 2017:
- IFE serum interpretation: An IgG kappa monoclonal protein is identified by serum immunofixation electrophoresis
- SPE interpretation: SPE M-protein 0.30 g/dL (High) Monoclonal gammopathy
My diagnosis is now listed as IgG kappa monoclonal gammopathy.
My doctor said that it is difficult to say if the MGUS has truly changed from light chain MGUS to IgG kappa MGUS or if the IgG monoclonal protein already was present in my body before and has now progressed to levels high enough to be detected by the SPEP. He said once he receives the results from today he will be able to tell if the previous jump in my levels was a one-time occurrence or if they are trending up to the point where I need to have another bone marrow biopsy and PET scan.
So I guess I probably won't ever know if I really was light chain MGUS and it changed or if I was mislabeled due to the protein not being able to be detected previously.
Re: Can light chain MGUS become "normal" MGUS?
Hi IndianaMom,
Thanks for the update. I hope that your latest tests show that the previous results were just a blip up, and that no major changes are taking place.
I'm curious about one thing. Did your doctor bring up himself the possibility that your MGUS hasn't really changed, but just couldn't be fully determined in the past? Or is it something he commented on because you brought it up yourself, based on the discussion here in the forum?
Good luck!
Thanks for the update. I hope that your latest tests show that the previous results were just a blip up, and that no major changes are taking place.
I'm curious about one thing. Did your doctor bring up himself the possibility that your MGUS hasn't really changed, but just couldn't be fully determined in the past? Or is it something he commented on because you brought it up yourself, based on the discussion here in the forum?
Good luck!
Re: Can light chain MGUS become "normal" MGUS?
Cheryl G,
No, my doctor did not initially address this. I asked if the new occurrence of the M spike was a normal progression of MGUS. After reviewing my previous testing, he gave me the explanation I shared in my last post.
He said the detection of the M-spike combined with the continuing rise of my free light chain level and ratio were the reason I had to come back at 90 days for repeat testing. He said if my results show a further increase in M-spike and free light chain results, he will order a bone marrow biopsy (my last was May 2016) and a PET scan (I've never had one). If my results show my levels are stable, then he will order repeat testing in 6 months. He said he's not comfortable with annual testing at this time. I should get my results on Monday or Tuesday.
No, my doctor did not initially address this. I asked if the new occurrence of the M spike was a normal progression of MGUS. After reviewing my previous testing, he gave me the explanation I shared in my last post.
He said the detection of the M-spike combined with the continuing rise of my free light chain level and ratio were the reason I had to come back at 90 days for repeat testing. He said if my results show a further increase in M-spike and free light chain results, he will order a bone marrow biopsy (my last was May 2016) and a PET scan (I've never had one). If my results show my levels are stable, then he will order repeat testing in 6 months. He said he's not comfortable with annual testing at this time. I should get my results on Monday or Tuesday.
7 posts
• Page 1 of 1