Polyclonal antisera-based assays are superior to monoclonal antisera assays for the identification of free light chains (FLCs)
Kappa (κ) and lambda (λ) free light chains are polymorphic, which means that there is a huge variation in κ and λ FLC epitopes.
To be effective in diagnosing and monitoring patients, any FLC immunoassay must be able to recognise all of the various forms of FLC proteins.
The polyclonal Freelite assay recognises the widest variety of free light chains to allow complete detection and accurate sample measurement
FLC assays based on monoclonal antibodies will recognise a limited variety of FLC epitopes
Monoclonal antisera-based assays are unlikely to recognise all forms of κ and λ FLC
If a patient is missed by a monoclonal assay, this problem cannot be corrected by subsequent batches containing the same monoclonal antibodies
The importance of missed patients cannot be underestimated; a rapid accurate diagnosis is essential to allow initiation of disease-specific treatment and prevent the development of complications, including irreversible renal failure, which is associated with reduced overall survival.
Freelite is the only serum free light chain assay recommended by name in International Guidelines