Prognostic value of polyclonal free light chains of serum immunoglobulins in patients with chronic lymphocytic leukemia

Free light chains (FLC) assay is an accurate, sensitive and easily reproducible method for diagnosing paraproteinemia and other diseases. It has been established that the parameters of FLC in MM and CLL may have a diagnostic value for determining the effectiveness of treatment. In the present work, we studied the clinical significance of polyclonal FLC (PFLC) in patients with CLL without monoclonal tumor FLC. Materials and methods. The prospective study included 42 patients with CLL II-III (87.8% of patients) and IV (7.4%) Rai stage. Treatment programs included FCR, BR programs and ibrutinib in cases of ineffectiveness of PCT. Complete response rates (CR), overall survival (OS), progression-free time (PFS), time to chemoimmunotherapy (TTC) were determined. The concentration of FLC in blood serum by the Free light method was determined before and after treatment. We used diagnostic antibodies to FLC κ and λ (Binding Site, England). Clonality was determined by the ratio 𝛞/λ outside the range of 0.26-1.65. Immunophenotyping of blood lymphocytes was performed by flow cytometry using a standard panel of Becton Dickinson monoclonal antibodies, as well as the expression of light chains κ and λ. For statistical processing of the results, the analysis of variance was used and the survival analysis was determined by the Kaplan-Meier method. Results. FLC clonality was established in 19 out of 42 patients (45.2%), polyclonality - in 23 patients (54.7%). The median concentrations of FLC in the group of patients without an FLC clone were 11.3 mg/l for κ and 12.3 mg/l for λ. Me sum of concentrations κ+λ was 23.5 mg/l, which is close to normal values (20 mg/l). In two subgroups of patients, divided according to Me values of the sum κ+λ FLC (23.5 mg/l), there were no significant differences in the number of PE, the duration of PFS and TTC. Among patients with polyclonal FLC, in the group with κ/λ FLC values below the median (0.64), TTC was 4.4±1.7 months, and in the group with elevated κ/λ - 20.1±5 months (p function show_eabstract() { $('#eabstract1').hide(); $('#eabstract2').show(); $('#eabstract_expand').hide(); }