The diagnostics and follow-up of monoclonal gammopathies such as multiple myeloma require precise analysis of the monoclonal component as well as the other immunoglobulins isotypes, which might be limited by the sensitivity of standard laboratory methods. New serum biomarkers were developed for routine practice in the last decades, such as the free light chain assays and more recently the heavy/light chain assay<strike>s</strike>. Studies have shown that serum free light chain measurement was useful in the identification and follow-up of pauci or nonsecretory myeloma, free light-chain multiple myeloma and AL amyloidosis. It is also an important prognostic marker for monoclonal gammopathy of undetermined significance and AL amyloidosis progression. Hevylite method enables quantitative analysis of heavy/light chain pairs of IgG, IgA and IgM immunoglobulins. This technique has a promising potential to enrich the standard analytic tools as it enables to assess the concentration and ratio of the levels of both tumor and physiological immunoglobulins (heavy/light chain pair suppression), which is not possible with serum protein electrophoresis or global quantitative analysis of immunoglobulin isotypes. This review includes the latest International myeloma working group recommendations and key data presented at the Euromedlab convention in June 2015 Paris regarding serum free light chain and heavy/light chain assays in the biological monitoring of dysglobulinemia.
Keywords: Euromedlab; Hevylite; free light chains; monoclonal gammopathy; myeloma.