New white paper compares polyclonal and monoclonal antibody based assays
Evans et al. compare Freelite, a polyclonal free light chain (FLC) assay, with monoclonal antibody-based assays. They review diagnostic performance with Myeloma patient samples and comment on the differing number of clinical studies using each assay. Also noted is why several limitations mean that international guidelines for serum free light chains cannot be assumed to apply to monoclonal antibody-based assays.
They conclude that to allow timely initiation of disease specific treatment and prevent development of complications associated with reduced overall survival (e.g. irreversible renal failure) an accurate FLC diagnostic test is essential.
Their paper answers a number of questions:
- Can monoclonal antibody-based tests recognise the wide variety of serum kappa and lambda monoclonal light chain molecules that polyclonal antibody–based assays do?
- Are monoclonal antibody-based assays as effective as Freelite in detecting FLC in Light Chain Multiple Myeloma patients?
- Are the absolute values of kappa and lambda comparable when measured by the 2 different types of assay? Therefore can international guidelines for monitoring Myeloma, developed using Freelite, apply to the new monoclonal assays.
- How do the 2 assays compare in terms of antigen excess, precision, linearity and batch to batch consistency?
Polyclonal Freelite assay. The gold standard for accurate quantification of free light chains.
Josie Evans PhD; Fiona Kilvington, MSc; Stephen Harding, PhD.
The Binding Site Group Limited, Birmingham, UK.