So I graphed everything I think of today. Lu thinks they are too hard to understand. Too much clutter. I agree, but still find them exciting (no comment!). Margaret explained the Bence Jones urine protein test today which for my wonderfully weird myeloma needs a bit of interpretation. A normal monoclonal protein is composed of two types of smaller molecules, one called a heavy chain and the other called a light chain. You may have heard of the heavy chain immunoglobulins, IgG, IgA, IgM... (mine are severely depressed.) The light chain portion is referred to as either kappa or lambda. The heavy and light chains are produced separately within the plasma cell and are then assembled to form a whole immunoglobulin. Normal healthy folks produce fully functional pathogen fighting warriors. When the light chains are attached to the heavy chains, the light chains are referred to as bound light chains. However, when the light chains are not attached to the heavy chains, they are called free light chains.
My laughing plasma cells partied to much and no longer know how to make the heavy part. They spew nothing but unbound free light chains. To add insult to injury the little bastards are very aggressive. Frits van Rhee et al published a paper a few months back in the journal Blood titled "High Serum Free-Light Chain Levels and Their Rapid Reduction in Response to Therapy Define an Aggressive Multiple Myeloma Subtype with Poor Prognosis". To the careful eye you will see in the graph below that my lambda light chain level responded in the first cycle of Thal/Dex and then promptly started ignoring the drugs. I wish Frits had published his paper back in February of 2006. I would have stopped taking Thal/dex after a couple months. I am anxiously awaiting the next free light chain (FLC) results to see if Velcade and the TRM-1 antibody turns the lights out on my plasma cell party.