[Aussie Annie]

MGUS & increasing free light chain ratio

by Aussie Annie on Mon Mar 21, 2016 2:39 am

Hi to everyone,

I have been following the forum for around 9 months since being diagnosed as MGUS in con­junction with several other (hopefully resolved) health issues.

Back in May 2015 I was diagnosed with an M-spike of 8 g/l (0.8 g/dL). Over the next few months the level fell to 6.9 g/l, 6 g/l, 4.8 g/l with a kappa level steady at around 30 g/l. No ratio ever measured.

I had very high ANA levels and a non functioning gallbladder (removed in July 2015) and a severe case of toxoplasmosis. Heavy antibiotic treatment was started for toxo in Sept 2015 and continued for 9 weeks.

Since completing the antibiotic treatment, the toxo has resolved, however, the M-spike rose back to 7 g/l (0.7 g/dL) and the kappa rose to 46 g/l, lambda 6.8 g/l, ratio 6.6.

In February M-spike 7 g/l, kappa 46 g/l, lambda 2 g/l, ratio 23.

My GP retested 5 weeks later and M spike 6 g/l (0.6 g/dL), kappa 55 g/l, lambda 5.1 g/l, ratio 11.

Given the free light chain ratio increases, where does this place me in the spectrum of disease?

I understand all the ranges for MGUS, smoldering multiple myeloma, and multiple myeloma in terms of M spike, plasma cell percentage etc. However, no one seems to be able to tell me if I am still MGUS or smoldering based on the free light chain ratio and what my prognosis is for progression or exactly what tests should be done.

I would greatly appreciate some clarification if anyone has any answers.

Thank you
Ann-Marie from Australia

[Aussie Annie]

Re: MGUS & increasing free light chain ratio

by Aussie Annie on Mon Mar 21, 2016 8:06 pm

Oops! All free light chain levels are mg/l, not g/l as stated.

Also, M-spike is IgG kappa. My IgG level is 14 g/l, so still normal. No immune paresis.

All other blood levels comfortably within normal levels. Xrays / CT shows no lytic lesions, though there is a cyst suggestive of old damage from a heavy fall as a child.

Any thoughts appreciated,
Ann-Marie

[Multibilly]

Re: MGUS & increasing free light chain ratio

by Multibilly on Mon Mar 21, 2016 9:05 pm

Hi Ann-Marie,

Welcome to the forum!

The difference between a diagnosis of smoldering multiple myeloma and MGUS is based primarily on the one's M-spike value and their bone marrow plasma cell percentage (BMPC) and NOT one's free light chain (FLC) values. So, to respond to your statement "no one seems to be able to tell me if I am still MGUS or smoldering based on the free light chain ratio" , you simply can't distinguish between MGUS and smoldering multiple myeloma based on your serum FLC values. However, if one's free light chain (FLC) ratio is > 100 (see details in link below), then one can consider this as a "myeloma defining event" (MDE). See this article:

SV Rajkumar, "New Criteria For The Diagnosis Of Multiple Myeloma And Related Disorders," The Myeloma Beacon, Oct 26, 2014

Note that your M-spike values from your lab tests are all fairly low. And your FLC ratio numbers have been fairly low as well. Both your M-spike and FLC ratio could very well be in line with a diagnosis of MGUS or smoldering multiple myeloma (I would tend to guess more towards MGUS given your fairly low M-spike, but that is just a guess from a layman). The wild card in your situation is your BMPC %.

Regarding what tests to get:

If you've never had a bone marrow biopsy (including a FISH test), you should get one to have as a baseline. You would be re-biopsied if any of your key numbers were to change dramatically.

The standard routine monitoring tests to get are a serum protein electrophoresis test, serum immunofixation test, serum free light chain assay, quantitative immunoglobulins, compre­hensive metabolic panel and a CBC. On your CBC and metabolic panels, you should especially track your hemoglobin, calcium and creatinine levels. These can help signal if any CRAB issues are developing. From all these test results, I think it's good to track and graph your M-spike, kappa FLC (since that is your involved FLC), FLC ratio, IgG/IgA/IgM, hemoglobin, calcium and creatinine levels. At least that is what I do and it helps me quickly see if I have any worrisome trends developing.

It sounds like you are already getting imaged (xrays, PET/CT, etc). A DEXA scan may be good to also consider at some point in time.

As far as risk of progression from MGUS or smoldering multiple myeloma to multiple myeloma is concerned, you might want to read these articles:

N Korde et al, "Monoclonal gammopathy of undetermined significance (MGUS) and smoldering multiple myeloma (SMM): novel biological insights and development of early treatment strategies," Blood, 2011 (link to full text of article)

"Risk of progression in smoldering multiple myeloma" (forum disc. started Sep 13, 2014)

AM Rajan & SV Rajkumar, "Interpretation of cytogenetic results in multiple myeloma for clinical practice", Blood Cancer Journal, 2015 (full text of article)

[Aussie Annie]

Re: MGUS & increasing free light chain ratio

by Aussie Annie on Tue Mar 22, 2016 5:34 am

Hi Multibilly,

Thanks so much for taking the time to respond. Thanks also for the links, which I have read.

I totally follow with everything you have said based on what I have read, except for one article I read on smoldering multiple myeloma which stated that a free light chain ratio of between 8-100 was an indication of smoldering multiple myeloma, with or without M spike of 30 g/l + and plasma cells 10% + (of course I can't find it again), which is why I was posting this question to the wider well informed Beacon members.

Unfortunately, my haematologist doesn't give any real weight to the FLC ratio 100+ as being significant with my otherwise low numbers and won't do a bone marrow biopsy – therefore, no FISH. She doesn't do them until she is ready to start treating multiple myeloma, so ... I may need to find a new doctor. I am having trouble finding a myeloma specialist in the greater Sydney area in private practice, as most treating doctors are regular haematologists here from what I can find out. I would really like to know whether I have a high-risk MGUS / smoldering multiple myeloma.

I have regular blood tests of all the ones you listed and they are ok so far. My main concern is missing the small window of opportunity to prevent the risk of organ damage (80% within 2 years) if the FLC ratio gets to 100 and my doctor doesn't want to act.

It's hard enough to come to terms with this disease without feeling that there is no clear path to follow.

Thank you again for the support.
Ann-Marie