title: Diagnostic value of immunoglobulin κ light chain gene rearrangement analysis in B-cell lymphomas.
abstract: Analysis of the immunoglobulin κ light chain (IGK) gene is an alternative method for B-cell clonality assessment in the diagnosis of mature B-cell proliferations in which the detection of clonal immunoglobulin heavy chain (IGH) gene rearrangements fails. The aim of the present study was to evaluate the added value of standardized BIOMED-2 assay for the detection of clonal IGK gene rearrangements in the diagnostic setting of suspected B-cell lymphomas. With this purpose, 92 specimens from 80 patients with the final diagnosis of mature B-cell lymphoma (37 specimens), mature T-cell lymphoma (26 specimens) and reactive lymphoid proliferation (29 specimens) were analyzed for B-cell clonality. B-cell clonality analysis was performed using the BIOMED-2 IGH and IGK gene clonality assays. The determined sensitivity of the IGK assay was 67.6%, while the determined sensitivity of the IGH assay was 75.7%. The sensitivity of combined IGH+IGK assay was 81.1%. The determined specificity of the IGK assay was 96.2% in the group of T-cell lymphomas and 96.6% in the group of reactive lesions. The determined specificity of the IGH assay was 84.6% in the group of lymphomas and 86.2% in the group of reactive lesions. The comparison of GeneScan (GS) and heteroduplex pretreatment-polyacrylamide gel electrophoresis (HD-PAGE) methods for the analysis of IGK gene rearrangements showed a higher efficacy of GS analysis in a series of 27 B-cell lymphomas analyzed by both methods. In the present study, we demonstrated that by applying the combined IGH+IGK clonality assay the overall detection rate of B-cell clonality was increased by 5.4%. Thus, we confirmed the added value of the standardized BIOMED-2 IGK assay for assessment of B-cell clonality in suspected B-cell lymphomas with inconclusive clinical and cyto/histological diagnosis.
authors.affiliation: Department of Molecular Diagnostics, Institute of Oncology Ljubljana, Ljubljana, Slovenia.
authors.forename: Ira
authors.initials: I
authors.lastname: Kokovic
authors.affiliation: Division of Medical Oncology, Institute of Oncology Ljubljana, Ljubljana, Slovenia.
authors.forename: Barbara
authors.initials: B
authors.lastname: Jezersek Novakovic
authors.affiliation: Department of Molecular Diagnostics, Institute of Oncology Ljubljana, Ljubljana, Slovenia.
authors.forename: Srdjan
authors.initials: S
authors.lastname: Novakovic
mesh_terms: D001402:B-Lymphocytes / Q000473:pathology*; D015321:Gene Rearrangement; D005821:Genetic Techniques; D006801:Humans; D007143:Immunoglobulin Heavy Chains / Q000235:genetics; D007145:Immunoglobulin kappa-Chains / Q000235:genetics*; D016393:Lymphoma, B-Cell / Q000235:genetics*; D016399:Lymphoma, T-Cell / Q000235:genetics; D012680:Sensitivity and Specificity
chemical_list: D007143:Immunoglobulin Heavy Chains; D007145:Immunoglobulin kappa-Chains