title: Diagnostic performance of serum free light chain measurement in patients suspected of a monoclonal B-cell disorder.
abstract: The present study aimed to determine the diagnostic performance of different testing strategies to diagnose malignant B-cell disorder or monoclonal gammopathy of unknown significance (MGUS). Sensitivity and specificity were determined in 833 consecutive patients investigated for a monoclonal gammopathy. Serum protein electrophoresis (PE), serum kappa/lambda free light chain (FLC) ratio, and serum and urine immunofixation electrophoresis (IFE) were performed in all patients. Twenty-eight patients were diagnosed with a malignant plasma cell disorder, 25 with B-cell non-Hodgkin lymphoma and 156 with MGUS. Serum PE (with follow-up IFE) plus FLC had a sensitivity of 82.3% and a specificity of 96.8% and missed one plasmacytoma and 23 patients with MGUS. Serum IFE plus urine IFE had a sensitivity of 92.3% and a specificity of 100% and missed two MGUS patients. Serum IFE plus FLC had a sensitivity of 93.8% and a specificity of 96.8% and missed one MGUS patient. Serum PE plus FLC had a significantly lower sensitivity than serum IFE plus FLC or serum IFE plus urine IFE for the diagnosis of MGUS. The sensitivity of serum IFE plus FLC was comparable to the sensitivity of serum IFE plus urine IFE. The specificity of serum IFE plus FLC, however, was lower than the specificity of serum IFE plus urine IFE.
authors: Department of Laboratory Medicine, University Hospital, Leuven, Catholic University of Leuven, Leuven, Belgium.
authors: Pieter
authors: P
authors: Vermeersch
authors: Lieve
authors: L
authors: Van Hoovels
authors: Michel
authors: M
authors: Delforge
authors: Godelieve
authors: G
authors: Mariën
authors: Xavier
authors: X
authors: Bossuyt
mesh_terms: D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000097:blood; D014408:Biomarkers, Tumor / Q000097:blood; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D007147:Immunoglobulin Light Chains / Q000097:blood* / Q000652:urine; D016393:Lymphoma, B-Cell / Q000175:diagnosis*; D008297:Male; D008875:Middle Aged; D009101:Multiple Myeloma / Q000175:diagnosis; D010265:Paraproteinemias / Q000175:diagnosis*; D012680:Sensitivity and Specificity; D055815:Young Adult
chemical_list: D015415:Biomarkers; D014408:Biomarkers, Tumor; D007147:Immunoglobulin Light Chains