Free Kappa and Lambda Light
Chains Plus Ratio
(Serum free light
carries either kappa- or lambda-light chains on its surface (a
Normal, polyclonal B-cells are a
mixture of kappa-B-cells and lambda-B-cells (one marker or the
When malignant B-cell clone proliferates it will lead to b-cell
of either only kappa- or only lambda-B-cells. (one marker,
and not the other, suggests malignancy)
Serum free light chains as marker for CLL?
Dr Furman writes: It is important to remember that
there are over 75 different prognostic markers for CLL. Serum free
light chains is just another one. Any time there is an increase in
the number of B cells, there can be an increase in the serum
immunoglobulins and serum free light chains. The serum
immunoglobulins are the antibodies produced by CLL cells. Every
antibody contains two heavy chains linked to two light chains. The
serum immunoglobulins are the complete molecule. You can also have
heavy chains alone (uncommon) or light chains alone (common)
secreted. The serum free light chains that are measured just
represent the light chains from the antibody.
Most CLL patients are hypogammaglobulinemic (low antibodies). Some
of these patients will still have elevated light chains, but many
will have low values for these as well. The light chains are usually
filtered in the kidney and do not accumulate very much in the serum
and it has only been the last 15 years that we have been able to
measure the serum free light chains. The times the light chains
accumulate are usually due to increased secretion or decreased
clearance by the kidneys. Thus, light chains can be a surrogate for
kidney function. Not necessary the cause of kidney dysfunction, but
just not cleared because the kidneys are not working properly.
It is extremely rare for CLL patients to develop kidney problems due
to light chains, but not so uncommon for myeloma and Waldenstrom's
patients to develop these problems There are two types of light
chains, kappa and lambda, and it is almost only lambda that can
cause the problem, sometime as resulting in amyloid.
I encourage patients to not worry about light chains as prognostic
markers and only use them in patients with kidney disease that might
be attributable to them.