title: Clinical comparisons of two free light chain assays to immunofixation electrophoresis for detecting monoclonal gammopathy.
abstract: Free light chains (FLCs) are useful biomarkers for the diagnosis and monitoring of various plasma cell dyscrasias. One hundred fifty-seven samples from 120 patients for screening or monitoring of monoclonal gammopathy (MG) were included. The new N Latex FLC assays (Siemens Healthcare Diagnostics GmbH, Germany) were compared with the Freelite FLC assays (The Binding Site Ltd., UK) and the results were analyzed with those of immunofixation electrophoresis (IFE). The Freelite FLC assay showed significantly wider assay ranges than the N Latex FLC assay. The correlation coefficients of the two FLC kappa (κ) assays, lambda (λ) assays, and the κ/λ ratio were 0.9792, 0.8264, and 0.9064, respectively. The concordance rate was 84.7% for the FLC κ assays, 79.6% for FLC λ, and 89.2% for the κ/λ ratio. The clinical sensitivity and specificity of the κ/λ ratios were 72.2% and 93.6% for the Freelite assay and 64.6% and 100% for the N Latex FLC assay. Two FLC assays showed good correlations and concordance. However, the clinical sensitivity of the κ/λ ratio was higher in the Freelite FLC assays; clinical specificity was higher in the N Latex FLC assay. Both FLC assays seem to have limited clinical utility in detecting MG in certain clinical settings.
authors: Department of Laboratory Medicine, Hallym University College of Medicine, Seoul 150-950, Republic of Korea.
authors: Han-Sung
authors: HS
authors: Kim
authors: Department of Laboratory Medicine, Hallym University College of Medicine, Seoul 150-950, Republic of Korea.
authors: Hyun Soo
authors: HS
authors: Kim
authors: Department of Laboratory Medicine, Hallym University College of Medicine, Seoul 150-950, Republic of Korea.
authors: Kyu-Sung
authors: KS
authors: Shin
authors: Department of Laboratory Medicine, Hallym University College of Medicine, Seoul 150-950, Republic of Korea.
authors: Wonkeun
authors: W
authors: Song
authors: Department of Internal Medicine, Hallym University College of Medicine, Seoul 150-950, Republic of Korea.
authors: Hyo Jung
authors: HJ
authors: Kim
authors: Department of Internal Medicine, Hallym University College of Medicine, Seoul 150-950, Republic of Korea.
authors: Hyeong Su
authors: HS
authors: Kim
authors: Department of Laboratory Medicine, Hallym University College of Medicine, Seoul 150-950, Republic of Korea.
authors: Min-Jeong
authors: 0000-0002-2775-2128
authors: MJ
authors: Park
mesh_terms: D000368:Aged; D004586:Electrophoresis / Q000379:methods*; D005260:Female; D006801:Humans; D007118:Immunoassay / Q000379:methods*; D007147:Immunoglobulin Light Chains / Q000276:immunology*; D008297:Male; D010265:Paraproteinemias / Q000097:blood / Q000175:diagnosis* / Q000276:immunology*
chemical_list: D007147:Immunoglobulin Light Chains