[tpt]

M-Spike and FLC

by tpt on Tue Aug 06, 2013 11:20 pm

Hello,

A lot of you talked about M-Spike when monitoring the activity of Myeloma. But we never had our M-Spike tested; the Doctor always looks for the Free Light Chains. (Dad has Kappa Myeloma.)

How is M-spike different to FLC? If Dad's FLC has been stalled, does it mean he have zero M-spike? Thanks.

[dnalex]

Re: M-Spike and FLC

by dnalex on Wed Aug 07, 2013 2:37 am

I think this is something that is very important to ask your father's myeloma doctor why he does not look for (or look for but does not talk about) the M paraprotein.

My guess, however, is that your father, like my mom, has light-chain only myeloma, or Bence-Jones Myeloma. In this case, I bet that your dad's doctor has been checking for M proteins and not detecting any. In light chain myeloma, it's going to be spikes in the kappa or the lambda light chain (kappa for your dad).

Best wishes,
Alex

[Dr. Peter Voorhees]

Re: M-Spike and FLC

by Dr. Peter Voorhees on Sat Aug 10, 2013 1:22 pm

I agree with Alex. If it is free kappa light chain myeloma, serum free light chain testing and 24-hour urine protein electrophoresis and immunofixation are the best ways to detect relapse. a serum protein electrophoresis and immunofixation will eventually become abnormal if the light chain levels get high enough, but it is a very insensitive test in this particular circumstance. The other tests are the way to go. If the myeloma was, for example, an IgG kappa myeloma at diagnosis, then the SPEP/immunofixation and serum free light chain testing are all useful for monitoring. I would discuss with your physician at the next visit.

Thanks!

Pete V.