Evaluation of the prognostic and predictive value of free light chains in patients with chronic lymphocytic leukemia – preliminary results

Abstract

Introduction

κ and λ serum free light chains (sFLCs) are produced during physiological lymphopoesis by plasmocytes and B lymphocytes in a constant ratio related to heavy chains. The measurement of sFLC plays an important role in the diagnosis and monitoring of patients with multiple myeloma (MM). The first reports suggested that sFLC disturbances might have prognostic value also in patients with chronic lymphocytic leukemia (CLL). Aim of the study: The aim of the study was to evaluate the relationship between sFLC concentration and recognized prognostic factors and clinical course of CLL. Materials and methods: The sFLC concentration was measured using a latex-enhanced immunoassay in 59 patients with newly diagnosed CLL. The relationship between sFLC concentration and time to start of the treatment (TFT), the response rate to therapy (ORR) and overall survival (OS) was assessed.

Results

A significant correlation was found between sFLC κ concentration and the clinical stage of leukemia according to Rai classification, β-2 microglobulin concentration, LDH activity, CD38 expression, as well as between sFLC λlevel and β-2 microglobulin concentration and platelet count (PLT ). There was also a correlation between the values of summated κ and λ and the clinical stage of disease according to Rai classification, β-2 microglobulin concentration, CD38 expression, white blood cells count (WBC), lymphocyte count (ALC) and hemoglobin (Hgb) concentration. The κ/λ ratio (FCLR) values were significantly different in the CD38+ and CD38- population.

Summary

Simple and reproducible clonality index, which constitutes the sFLC concentration assessment, can be an attractive, potential prognostic marker in patients with CLL, however further studies are needed on a larger group of patients especially in relation to the predictive value of sFLC.