[DanaH]

Re: Can you have an M-spike but a normal FLC ratio?

by DanaH on Tue Jan 28, 2014 11:42 pm

Thanks Multibilly,

So when I hear someone w/ SMM or multiple myeloma who say they have "normal" FISH or normal cytogenetics, that really just means they didn't test positive for the most "common" or "problematic" abnormalities found most often in multiple myeloma. But their cells may actually have chromosome abnormalities, just not the ones they "worry" about w/ multiple myeloma. Thanks for helping to clear up my confusion.

You are really so incredibly informed about all of this, thanks so much for being so willing to share with us.

Dana

[Covelo]

Re: Can you have an M-spike but a normal FLC ratio?

by Covelo on Thu Jan 30, 2014 8:18 pm

I had MGUS for at least 7 years with an M-spike of 1.8 (lambda restricted) and normal FLC levels. My lambda was always at the high end of the range but within normal.

Was diagnosed with primary AL amyloidosis last year and did 7.5 cycles of CyBorD, ending Nov 1. Bone marrow biopsy at the diagnosis revealed no myeloma and FISH analysis showed t(4;14) with 13 deletion I believe. Getting back to pseudo normal now. Total IGG levels still below normal range but climbing.

The difficulty with normal FLC levels is that I am lacking a major, and possibly the most important, indicator for following progression of the disease. That assay is basically meaningless in my case. The m-protein is indirectly important. I have kidney only involvement so we follow the proteinuria, but that is slow to respond.

So yes you can have an m-spike with normal FLC levels, though I do not technically have myeloma.

[dianaiad]

Re: Can you have an M-spike but a normal FLC ratio?

by dianaiad on Thu Jan 30, 2014 9:24 pm

Am I glad to hear that I"m not the only cat in the room dealing with this situation! I was diagnosed with a rather high M-spike, a P17 deletion (making me 'high risk') and dead normal light chains. They have remained 'normal' all through my CyBorD treatment, the bone marrow transplant ... the whole enchilada.

I have no idea how common this is, what it means, or how it affects prognosis, if it affects prognosis at all. I will say that the only symptom I had at diagnoses was a mild anemia, with no bone involvement or other organ damage. I have no idea if that makes any difference, either.

Certainly my doctor simply shrugged it off ... but then he's not the most communicative guy on the planet, and I am stuck with him.

[Multibilly]

Re: Can you have an M-spike but a normal FLC ratio?

by Multibilly on Thu Jan 30, 2014 9:53 pm

OK, so now you really got me thinking about this. See this article if your really want to get into the nits of the phenomenon and ponder various rat holes as you try to figure this out.

http://www.clinchem.org/content/47/4/673.full

The interesting paragraph is this one:

One potential drawback of quantitative FLC assays is that they cannot directly determine clonality, although altered κ:λ ratios are highly suggestive of clonality, particularly if extreme. On the other hand, ratios might be normal in early disease or during clinical remission, and increased polyclonal FLC concentrations will mask low concentrations of monoclonal FLCs. In addition, biclonal gammopathies of different FLC types could produce normal κ:λ ratios although the concentrations of both molecules might be increased. In all of these situations, clonality must be confirmed by electrophoresis. In spite of these limitations, the potential benefits of simple FLC immunoassays for assessing monoclonal gammopathies, in terms of improved sensitivity, accuracy, cost savings, and the use of serum as a test medium, are considerable.

There is also mention of you pesky "non-FLC producers" made here (search for "non-FLC" to get to the sentence of interest):

http://www.wikilite.com/wiki/index.php?title=Monitoring_IIMM_patients_using_sFLCs&diff=prev&oldid=8038

In a study of 51 patients...4 patients had abnormal bone marrow biopsies but normal sFLC levels (non-FLC producers).

So, you are obviously not alone....

[DanaH]

Re: Can you have an M-spike but a normal FLC ratio?

by DanaH on Fri Jan 31, 2014 1:18 am

Thanks Covelo and dianaiad for reminding me of my original question ! We got caught up in the chromosome abnormalities and I became somewhat sidetracked !

Multibilly, I will sink my teeth into the links you just provided, and once again, a big THANKS !

No complexity whatsoever with this disease

All the best to all who have responded to the original and ensuing topics.

Dana

[DanaH]

Re: Can you have an M-spike but a normal FLC ratio?

by DanaH on Thu Feb 06, 2014 11:36 am

Hi all,

I found a source to answer my original question and supports the responses that said they had only an mspike w/ normal FLC's and FLC ratio.

http://www.thebindingsite.com/intactimmunoglobulinmultiplemyeloma

Thanks again everyone.

Dana