[ecparetti]

Inconsistent lambda light chain results

by ecparetti on Sun Oct 02, 2016 4:06 pm

Hello to all,

I am a 64-year-old male and have had lambda light chain myeloma since 2005. I had tandem stem cell transplants in Boston in December 2006 and April 2007. I have been on Revlimid since late 2007 (mostly 5 mg).

I have had one oncologist since beginning treatment whom I trust. I added a Boston hospital specialist in February 2015 as a second opinion (lambda numbers were about 150 mg/l).

My lambda numbers began going up mid 2015 to 600 mg/l (consistent with both doctors). After few months off 5 mg Revlimid, I started back on 25 mg from October 2015 to July 2016 (presently on 15 mg). My lambda numbers with my oncologist from February to September 2016 are about 1000 mg/l. I looked into switching to Pomalyst. My lambda numbers in Boston in May and September 2016 are 70 mg/l. Has anyone run into similar discrepancies?

The September labs were done less than 2 weeks apart at both hospitals. I am feeling fine but curious what could cause this. No reasons for the differences have been found as of yet.

Thanks for your help.

[Multibilly]

Re: Inconsistent lambda light chain results

by Multibilly on Sun Oct 02, 2016 6:40 pm

The first thing I would check is to be sure you are using the same units of measure for all the serum free light chain results. Some labs use mg/dL and some use mg/L for free light chain tests.

The second thing I would check is that all the labs are measuring FREE light chains and that one of them isn't measuring TOTAL light chains. Doctors sometimes screw up and order a total light chain test instead of a free light chain test.