Useful links for figuring out Freelite test results

A blog reader who was recently diagnosed with smoldering myeloma wrote to me about his rather high serum free light chain (Freelite) test results. Our exchange reminded me of how puzzled I was back in May when I read my first (ever) Freelite results. At the time, my blog reader Rudi very kindly helped me decipher them, but I neglected to post the link to “The Binding Site, Inc.” Here it is: So, if you are as confused about your Freelite results as I was, all you have to do is have a look at the chart on this page. Very very helpful. 

If you have no idea what I’m talking about (and if you are a MGUS, SMM or even MM patient and have never had a Freelite test), go have a look at the exhaustive Freelite brochure published in May 2009 by the IMF, International Myeloma Foundation: Here you will find everything you ever wanted to know about serum free light chains and more…much more! The Freelite test is an important one–and here I must pause for a second to thank my friend Sherlock for suggesting that I have this test in the first place–so, if you belong to the above-mentioned categories, please add it to your list of blood tests. The IMF brochure, by the way, is available in five different languages, including Italian.

And finally, here is an interesting excerpt from a 2008 interview with Guido Tricot, MD, Ph.D. (see page 3 of the Binding Site’s newsletter: If you entertain the diagnosis of MGUS or smoldering myeloma and you see a Freelite kappa that’s over 100 mg/L, usually you know this is not MGUS. Hmmm, I don’t find anything “entertaining” about a MGUS or SMM diagnosis 😉 , but (okay, seriously, now) my Freelite kappa result is less than half that number. And, in fact, it went down a bit further in October. Based on my results, I fall into the “MGUS with BM suppression” category. Needless to say, I am very pleased…!


  1. I thought I would add that the Freelite test is just one of several that is/will be used to assess status and guide a treatment strategy. I was diagnosed with MM and tested ‘normal’ on all values of the Freelite test, lambda, kappa and kappa/lambda ratio. Everyone secretes antibodies (heavy and light chains) in a varying and unique profile depending in part on our unique genetics as well as the presence of any pathogens that are being neutralized by a healthy immune response (antibodies). Those of us with rogue colonies of monoclonal plasma cells are no different. We are all uniquely wonderful!

    My rogue colonies of laughing plasma cells are so intoxicated they don’t make a complete antibody (heavy + light chain), just the light chain part. The Freelite test is very important for monitoring my disease as I don’t have a M-spike that is evidence of a complete monoclonal antibody.

  2. Hi LP Cells — If you tested ‘normal’ on the Freelite test that is a good prognostic sign –unlike my lambda LC which is high with a low kappa/lambda ratio. And if you had no M-spike then I gather it was the bone marrow biopsy or other test that made the diagnosis of MM?

    “My rogue colonies of laughing plasma cells are so intoxicated they don’t make a complete antibody (heavy + light chain), just the light chain part.” Well said and same for me –I am worried that one day my plasma cells will be crying! Gerry

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