The Diagnostic Value of Kappa/Lambda Ratios Determined By Flow Cytometric Analysis of Peripheral Blood and Bone Marrow Specimens in B-Cell Chronic Proliferative Disease

Background. Previous studies have suggested that analysis of the distribution of surface immunoglobulin light chain kappa and lambda by flow cytometry (FC) provides evidence for monoclonality of B cell tumors in patients with persistent lymphocytosis. The objective is this study is to investigate the efficiency of FC in determination of monoclonality in patients with persistent lymphocytosis through the analysis of kappa and lambda light chain of immunoglobulin expression (kappa/lambda tests). Methods: Samples of peripheral blood from 43 patients with B-CLD were analyzed. They were analyzed by FC with monoclonal antibody panel as: CD3, CD4, CD5, CD8, CD10, CD19, CD22, CD20; CD103; FMC7; CD23, CD25, CD38, CD45, CD16/CD56, HLADR, anti- heavy chain of immunoglobulin (IgH), anti-heavy chain m and d of immunoglobulin (IgM/IgD) and anti-light chains (kappa and lambda) of immunoglobulin. In addition, information about sex, age and clinical and hematological data from the patients were also evaluated. Results. A relation between kappa / lambda higher than 10:1 was found in all samples, suggesting a monoclonal B cells proliferation with 86% of the samples displayed kappa light chain of immunoglobulin expression and 14% displayed lambda light chain of immunoglobulin expression. The immunophenotyping data associated with the hematological and clinical ones, confirmed 35 cases of B-cell chronic lymphocytic leukemia, 3 cases of B-cell prolymphocytic leukemia, 3 of hairy cell leukemia, one case of Waldenstrong macroglobulinemia and mantle cell lymphoma. Conclusions. The results showed that the kappa and lambda light chain of immunoglobulin expression analysis by FC is a simple and effective methodology in the malignant B- cell proliferation.