La misura delle catene leggere libere e i recenti criteri diagnostici del mieloma multiplo

AUTORI

ABSTRACT

The free light chain measurement and the recent Multiple Myeloma diagnostic criteria

In 2014, the International Myeloma Working Group updated the criteria for the diagnosis of Multiple Myeloma (MM), adding to the classic CRAB features (hypercalcaemia, renal failure, anemia, and bone lesions) a recently validated biomarker and recommended the implementation of this criterium in the routine practice. The biomarker is the ratio of involved to non-involved free light chain ≥100, provided that the involved light chain is ≥100 mg/L. We report the case of a man aged 68, referring to our Hematology Unit in March 2016 who was diagnosed with a monoclonal gammopathy of undetermined significance since 2009. Serum protein electrophoresis and immunofixation were performed, along with serum free light chain (sFLC) quantification. During the follow-up, despite the small peak entity, the sFLC kappa concentration was very high (3684 mg/L; reference interval 3.3-19.40) with an abnormal sFLC ratio (304; reference interval 0.26-1.65). At that stage, the patient did not show any signs of CRAB features, however a drug treatment was started. For months later, a magnetic resonance revealed a numer of lytic lesions. This case underlines the crucial role of sFLC in the management of patients with plasmacell dyscrasias and shows how sFLC ratio can induce early treatment before the development of major organ damage.

BIBLIOGRAFIA