[Guest1]

Kappa light chains elevated, all else normal - meaning?

by Guest1 on Thu Feb 13, 2014 8:02 pm

So as I've posted before, I am IGA Kappa and was diagnosed almost four years ago. About a year ago, my light chains started going up and as of about a month ago, the Kappa number is around 94. Every single category is within reach with the exception of my Kappa number.

This weekend, I had a PET Scan done and there is no evidence of multiple myeloma in my body.

So what gives?

[Multibilly]

Re: Kappa light chains elevated, all else normal - meaning?

by Multibilly on Thu Feb 13, 2014 8:29 pm

So, a PET/CT just picks up on bone lesions and tumors due to the myeloma. It doesn't pick up on the presence of the individual myeloma cells distributed throughout your bone marrow, nor things like the monoclonal immunoglobulins in your blood (at least that was the case with my PET/CT). Therefore, you can't say you don't have "evidence of multiple myeloma" by virtue of having a clean PET/CT. But you can thankfully say that you don't have any bone involvement or extramedullary tumors due to the multiple myeloma by virtue of having a clean PET/CT.

Only a bone marrow biopsy can really tell you what your myeloma plasma cell burden is. The other serum and urine tests for FLCs, M-spike, etc can be used as surrogate measurements for the bone marrow biopsy plasma cell results with most patients.

But if your M-Spike is non-existent or very low (is it?) and you have a high kappa FLC, you could possibly have a light chain restricted form of multiple myeloma such as nonsecretory multiple myeloma or oligosecretory multiple myeloma.

[Dr. Ken Shain]

Re: Kappa light chains elevated, all else normal - meaning?

by Dr. Ken Shain on Fri Feb 14, 2014 9:44 am

As with every test that we run on your blood or imaging of your body, there is a limit of what each can detect. And some times not everyone's disease will be postive- for instance only about 70% of myeloma patients will have PET- positive disease. Also keep in mind that response criteria today include bone marrow biopsy, SPEP-IFe, UPEP-IFE, SFLC, and surveys. PET/CT and MRIs have not yet to be included in response grades. Although a number of studies have highlighted that potential positive influence of PET/CT negative and/or MRI negative findings on outcomes.

Moreover, as I stated in an earlier post, even when everything is "negative" there is still myeloma; it is just below the level of detection from the test that we currently use. To this end, new tests- whether imaging (PET/CT MRI) as well as multiparameter flow, PCR, and next generation sequencing are being used to try to detect even smaller amounts of disease. Increasing our ability to measure depth of response.

In your case, a kappa SFLC of 94mg/L(?) is very small and as long as it remains stable (and you are having no issues with therapy or disease related events) everything is excellent.

In other cases, if there is a bit of renal insufficiency (elevated creatinine) from disease (or something) your light chains can remain slightly elevated and be unrelated to disease.

We wish you the best.