[Restlessrebel]

What free light chain level is too much?

by Restlessrebel on Sat Jun 13, 2015 1:23 pm

For the last 3 years, most of my labs have been normal with the exception of my lambda light chains, which are now at 1300. My other labs that concern me are my IgG, IgA and IgM levels. They are steadily going down each 3 months. My last test showed my IgM at 27. I do not have an M-spike, but my oncologist suggested that due to my light chain amounts, he will continue to watch every 3 months. How much is too much before starting treatment?

[Multibilly]

Re: What free light chain level is too much?

by Multibilly on Sat Jun 13, 2015 2:50 pm

Hi Confused,

Folks can better help you if you answer the following questions:

You say you don't have an M-spike. Are you currently diagnosed as having light chain restricted smoldering multiple myeloma or light chain restricted MGUS?

What are the units of measure for your lambda free light chain (FLC) number? To be clear, is this a lambda FLC number from a blood serum free light chain test?

What is your FLC ratio (kappa/lambda)?

Just what are the values of your IgG, IgA and IgM (including units of measure and the normal reference ranges on your lab tests for each please)?

[Beacon Staff]

Re: What free light chain level is too much?

by Beacon Staff on Sun Jun 14, 2015 8:16 am

Hi Confused,

If you've posted in the forum before, it might be useful if you logged in before posting. This makes it easier for others here in the forum to go back to your earlier postings, where there sometimes can be answers to important clarifying questions like the ones Multibilly has asked.

Take care.

[Restlessrebel]

Re: What free light chain level is too much?

by Restlessrebel on Mon Jun 15, 2015 1:24 am

My FLC levels are:

Lambda light chains 1310.8 mg/L, normal is 5.71 to 26.3 mg/L
Kappa light chains is 6.1 mg/L, normal is 3.3 to 19.4 mg/L

I believe my ratio is 0.1

  Mar 13, 2014 Mar 11, 2015 Jun 8, 2015 Normal
IgA 209 178 162 82 - 453 mg/dL
IgG 1050 956 836 751 - 1560 mg/dL
IgM 39 29 27 46 - 304 mg/dL

Sorry for not being clear. I am trying.

[Multibilly]

Re: What free light chain level is too much?

by Multibilly on Mon Jun 15, 2015 8:07 am

Hi Restlessrebel,

This stuff is confusing, isn't it?

Based on the free light chain numbers you posted, your involved/uninvolved free light chain ratio is 1310.8/6.1= 215. This qualifies as an MDE ("myeloma defining event") under the new IMWG diagnostic criteria. See this article to better understand all this:

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

Updated Definition of Multiple Myeloma

The revised IMWG criteria will allow, in addition to the classic CRAB features, the following [marker] as a “myeloma defining event” (MDE) ...

Serum involved / uninvolved free light chain ratio of 100 or greater, provided the absolute level of the involved free light chain is at least 100 mg/L (a patient’s “involved” free light chain – either kappa or lambda – is the one that is above the normal reference range; the uninvolved light chain is the one that typically is in, or below, the normal range)."

Having an MDE doesn't automatically mean that one would start treatment. Starting treatment based on an MDE can be at the discretion of the patient and the doctor. As an example, I am smoldering and my specialist would not start me on treatment based on an MDE without accompanying CRAB organ damage, nor am I in any rush to begin treatment. But others may certainly consider starting treatment under the circumstances, and that may very well be the right decision for them.

I think Dr. Rajkumar summarized his article nicely by closing with the statement:

Finally, no written criteria can substitute clinical judgment. In many cases, physicians will need to continue to use judgment in making decisions on which patients need immediate therapy, and in deciding when con­tinued observation will be in the patients’ best interests".

As far as your IgG, IgA and IgM levels dropping, that "may" be due to a phenomenon known as immunoparesis, whereby your uninvolved immunoglobulins are being suppressed by the multiple myeloma disease. It's good to keep an eye on these levels, as their suppression can make you more likely to develop infections since your immune system is being knocked down.

In any case, I'm not a doctor and a doctor really needs to comment on all this. I hope that you have found a good multiple myeloma specialist to work with you.