[lwem]

Prognostic value of free light chain levels (not ratio)

by lwem on Fri Jul 29, 2016 2:12 pm

Hi all -

I have seen a lot of discussion regarding the prognostic value of the free light chain ratio, and I understand its significance.

Does anyone know if free light chain levels themselves have any prognostic significance?

My husband was diagnosed in April 2015. At that time, his kappa free light chain level was 13 and lambda free light chain level was 1. Even though he has IgG kappa multiple myeloma, his kappa free light chain level has never been out of range. The ratio was high obviously due to the low lambda level (his uninvolved immunoglobulins have been suppressed since diagnosis). He has IgG kappa multiple myeloma and his IgG was 5,129 at diagnosis, M-spike 3.59 g/dL (35.9 g/l).

His kappa and lambda light chain values have always been well within normal to low range, even if the ratio was occasionally high due to low lambda (the ratio is now normal).

Does anyone know if having normal light chains confers a favorable prognosis? He is doing very well in complete remission (CR) – no M-spike and normal kappa-lambda ratio.

Thank you.

Laurie

[JPC]

Re: Prognostic value of free light chain levels (not ratio)

by JPC on Sat Jul 30, 2016 8:31 am

Hi Laurie:

I am not knowledgeable regarding light chains. It has never been an issue for my wife. In her case, the light chains are secondary to the M-spike. The light chains went out of range, but only after the M-spike went very high. If you have that type of myeloma, the light chains may not be a prognostic indicator. Over time, if the multiple myeloma evolves (as it usually does), then the light chains may become the leading issue. This would be due to a secondary clone developing, that was light-chain dominated.

I do recall reading that very generally M-spike dominated multiple myeloma does respond a bit better to treatment, and light chain dominated multiple myeloma does overall tend to be a little more aggressive. As others have mentioned, one or two readings out of range would not be of concern, as there are natural fluctuations to the light chains, but if they trended out range significantly over time, that would be an issue.

Good luck to you.

[Canuck Bob]

Re: Prognostic value of free light chain levels (not ratio)

by Canuck Bob on Mon Aug 08, 2016 3:58 pm

There are so many prognostic schedules and relapse protocols regionally and nationally it makes answers a bit confusing. I recently relapsed officially and my first marker was a kappa light chain over 100. I'm a Canadian. My M-spike followed, but the real marker that initiated treatment was the light chain. I would consider the test as significant to prognostics. I didn't track it, but now track it like a hawk after a mouse!