White blood cells called plasma cells produce the proteins known as light chains. Lambda and kappa light chains are the two different kinds of light chains. The quantity of lambda and kappa free light chains in the blood is determined by a free light chains test. A disturbance of the plasma cells may be present if the level of free light chains is higher or lower than usual. These include amyloidosis, a disorder that results in a risky protein buildup in various organs and tissues    and multiple myeloma, a malignancy of plasma cells.