Section Contents


  • Freelite® assays are recommended by name in International Myeloma Working Group guidelines.
  • An involved/uninvolved sFLC ratio of ≥100 (and involved sFLC concentration of ≥100 mg/L) is one of the diagnostic criteria for multiple myeloma.

National and international guidelines for identifying and managing patients with plasma cell dyscrasias are published and updated on a regular basis. These guidelines are widely adopted for assessing new patients and for patient entry into clinical trials. This chapter provides an overview of guidelines that include serum free light chain (sFLC) and/or immunoglobulin heavy/light chain (Hevylite®; HLC) analysis (identified in blue). This chapter contains the guidelines for multiple myleloma (MM) and some related disorders while guidelines for AL amyloidosis are covered in Chapter 28.

All guidelines and proposed clinical utilities relating to sFLCs have been based upon data generated using Freelite® kits manufactured by The Binding Site. In some countries, products intended for measurement of sFLC have been made available by other manufacturers (Chapter 8). Trials of such products have produced poor correlations with sFLC concentrations determined using Freelite. Therefore, it is unlikely that other products will have the same clinical utility or give compliance with current guidelines listed in this chapter.