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Volume:
Biochimica Clinica 2013; 37(5) 395-404
Pubblicato on-line:
DOI:
Towards improved measurement of serum free light chains: clinical and laboratory issues
AUTORI
1Chemical Pathology Department, Pathology Queensland, Royal Brisbane and Women’s Hospital, Herston, Qld, Australia
2Haematology Department, Pathology Queensland, Princess Alexandra Hospital, Woolloongabba, Qld, Australia
3School of Medicine, University of Queensland, Brisbane, Qld, Australia
ABSTRACT
Serum free light chain (FLC) assays are now well established in the diagnosis and monitoring of plasma cell disorders. Nonetheless, the introduction of FLC measurement into clinical laboratories has not been without difficulty. In this paper we ask several questions about FLC measurements and describe some of the limitations and possible solutions. Main analytical issues include difficulties in defining the measurand and specificity requirements for anti- FLC antibodies, inadequate imprecision and bias and a lack of harmonised results across platforms and between different assays with the need for standardised sample dilution procedures to detect antigen excess, nonlinearity and interferences in FLC assays. Among the clinical issues a consistent approach is required to FLC reporting including standardised units, commenting and interpretation, and assay validation is required in specific disease rather than general patient populations. Collaboration is required between assay developers, laboratory scientists and clinicians to overcome these limitations in the next generation of assays.