[Determination of light chains in serum]

Free light chains of the immunoglobulin are identical to the Bence Jones protein. In 2001, a commercially available assay for the measurement of free light chains in serum (sFLC) became available (FreeLite Free Kappa & Free Lambda assay). Evidence from the use of the sFLC analysis is rapidly building, and the analysis is a potentially powerful supplement to the diagnostic tools already used in the diagnosis and monitoring of patients with monoclonal plasma cell disorders. However, there are several unsolved aspects for the use of this analysis which must be considered before sFLC can be used optimally in a daily clinical setting.