Serum monoclonal and polyclonal free light chains in newly diagnosed Egyptian patients with diffuse large B-cell lymphoma: their impact on event-free and overall survival

Abstract

Background/aim Diffuse large B-cell lymphoma (DLBCL) constitutes the largest subtype of B-cell non-Hodgkin's lymphomas. The prognostic ability of the International Prognostic Index in the era of immunochemotherapy is modest. New prognostic biomarkers are mandatory to provide new insights into the risk stratification of DLBCL. Nowadays, serum-free light chain (sFLC) assay is being applied to hematologic non-plasma cell B-cell lymphoid malignancies. The aim of our work was to investigate the prevalence and prognostic value of elevated sFLC (monoclonal and polyclonal) in DLBCL and their impact on event-free survival (EFS) and overall survival (OS). Patients and methods This cohort study included 58 patients with DLBCL. Pretreatment serum samples were taken to detect κ and λ sFLCs with enzyme-linked immunosorbent assay. Patients were followed up every 3 months and computed tomographic scan was done every 6 months for 24 months after treatment. EFS and OS were estimated. Results Twenty-four patients (41.38%) had elevated κ or λ sFLC. Thirteen patients (22.41%) and 11 patients (18.97%) had monoclonal and polyclonal elevated sFLC, respectively. EFS and OS significantly decreased in patients with elevated sFLC and in those with abnormal sFLC ratio (monoclonal elevated sFLC). OS significantly decreased in patients with monoclonal elevated sFLC when compared with those with polyclonal elevated sFLC, but there was no difference between monoclonal and polyclonal elevated sFLC patients as regards EFS. Conclusion Elevated sFLC and abnormal sFLC ratio (monoclonal elevated sFLC) correlate with disease outcome (EFS and OS). There was no difference between monoclonal and polyclonal elevated sFLC as regards EFS but there was significant difference as regards OS.