Serum-free light-chain analysis in diagnosis and management of multiple myeloma and related conditions

Abstract

The introduction of the serum-free light-chain (S-FLC) assay has been a breakthrough in the diagnosis and management of plasma cell dyscrasias, particularly monoclonal light-chain diseases. The first method, proposed in 2001, quantifies serum-free light-chains using polyclonal antibodies. More recently, assays based on monoclonal antibodies have entered into clinical practice. S-FLC measurement plays a central role in the screening for multiple myeloma and related conditions, in association with electrophoretic techniques. Analysis of S-FLC is essential in assessing the risk of progression of precursor diseases to overt plasma cell dyscrasias. It is also useful for risk stratification in solitary plasmacytoma and AL amyloidosis. The S-FLC measurement is part of the new diagnostic criteria for multiple myeloma, and provides a marker to follow changes in clonal substructure over time. Finally, the evaluation of S-FLC is fundamental for assessing the response to treatment in monoclonal light chain diseases.

Keywords:

• AL amyloidosis
• electrophoresis
• immunofixation
• prognosis
• response to therapy
• screening

Disclosure statement

The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.

Funding

Authors are supported by grants from the “Associazione Italiana per la Ricerca sul Cancro” Special Program Molecular Clinical Oncology 5 per mille n. 9965, from the Cariplo Foundation [n 2013–0964] and from the Italian Ministry of Health (Target Research “Cardiac amyloidosis: molecular mechanism and innovative therapies for a challenging aging related cardiomyopathy”).