Elevated kappa light chains with IgG lambda IFE?

by **Mike F** on Fri Sep 05, 2014 4:18 pm

Elevated kappa light chains with IgG lambda IFE?

by Mike F on Fri Sep 05, 2014 4:18 pm

Hi all -

Another "weird test result" question here.

I was diagnosed with IgG lambda myeloma a couple of years ago. At the time, my M-spike was elevated and my lambda light chain levels were very high.

After induction with Revlimid and an autologous stem cell transplant (ASCT), everything went back to normal - no M-spike, normal light chain number.

Last June, the M-spike reappeared at 0.1, and then went up to 0.3 in July. Light chain numbers stayed within normal ranges.

I recently got results back from the August blood draw, and although my lambda light chain number was within the normal range, my kappa number had risen to 52.3 mg/L - well above the normal range which tops out at 19.4. (Of course, that threw the ratio out of whack as well.)

I just got the results of my serum electrophoresis (SPEP) and immunofixation electrophoresis (IFE) back, and my M-spike is down to 0.1 (a "faint band") with the IFE showing IgG lambda.

So what's the deal here? How can I have elevated kappa light chain levels with an IFE that shows IgG lambda?

Thanks in advance!

by **Dr. Jonathan Kaufman** on Fri Sep 05, 2014 6:47 pm

Re: Elevated kappa light chains with IgG lambda IFE?

by Dr. Jonathan Kaufman on Fri Sep 05, 2014 6:47 pm

Mike F,

There are a few reasons that you could get a result like this. The least likely reason (very unlikely) is that you have a new kappa restricted clone.

Other possibilities could be related to kidney function. If you kidney function is normal, then that's not it.

You could have a very robust recovery of your normal plasma cells that are primarily kappa. We often see this with intact immunoglobulins, and that is called an oligoclonal band. Having oligoclonal bands is associated with an improved outcome after treatment.

The other possibility is what I like to call a "laboma", or an error in the reporting of the test.

It is possible that the result is really 5.23 or 0.523, and they just put the decimal point in the wrong place. I've seen that happen before. And if I don't think a test makes sense (like yours), I call the lab to see if they can look at it.

Best wishes,

Jlk

by **Mike F** on Fri Sep 05, 2014 7:02 pm

Re: Elevated kappa light chains with IgG lambda IFE?

by Mike F on Fri Sep 05, 2014 7:02 pm

Thanks much for the response, Dr. Kaufman!

I work in a lab myself, and am unfortunately familiar with the potential error issues (not the I'VE ever done ANYTHING like that ;-)

), so that was the first thing that came to mind.

Kidney function is good. Very glad to hear that a new clone is an unlikely explanation. I guess I'll see how the next set of tests look.

Thanks again!