scholarly journals Serum Free Light Chain Assay and κ/λ Ratio: Performance in Patients With Monoclonal Gammopathy-High False Negative Rate for κ/λ Ratio

2017 ◽  
Vol 9 (1) ◽  
pp. 46-57 ◽  
Author(s):  
Gurmukh Singh
Keyword(s):  
Light Chain ◽  
Monoclonal Gammopathy ◽  
False Negative ◽  
False Negative Rate ◽  
Free Light Chain ◽  
Serum Free ◽  
Serum Free Light Chain ◽  
Negative Rate ◽  
High False Negative Rate

scholarly journals Serum Free Light Chain Assay in Monoclonal Gammopathic Manifestations

2019 ◽  
Vol 50 (4) ◽  
pp. 381-389 ◽  
Author(s):  
Won S Lee ◽  
Gurmukh Singh
Keyword(s):  
Light Chain ◽  
False Negative ◽  
False Negative Rate ◽  
Free Light Chain ◽  
Light Chains ◽  
Free Light Chains ◽  
Serum Free ◽  
Serum Free Light Chain ◽  
Associated Lesions ◽  
Serum Free Light Chains

Abstract Background Serum free light chain assay is used in the diagnosis and monitoring of monoclonal gammopathic manifestations. For the kappa (κ)/lambda (λ) ratio, there is a 36% false-positive rate in patients without monoclonal gammopathic manifestations and a 30% false-negative rate in patients with monoclonal gammopathic manifestations. This study was undertaken to address the higher false-negative rate in λ chain–associated monoclonal lesions. Methods Results of serum protein electrophoresis, serum immunofixation electrophoresis, and serum free light chain assays were reviewed retrospectively. The results for serum free light chains in cases of intact immunoglobulin monoclonal gammopathic manifestations only were analyzed. Results Concentrations of involved serum free light chains were significantly higher in κ chain–associated lesions than in λ chain–associated lesions. The concentration of uninvolved light chains was significantly higher in λ chain–associated lesions. Conclusions κ light chains are present in significantly greater abundance than are λ chains in their respective monoclonal lesions. Moreover, κ and λ light-chain levels are not comparable for similar quantitative levels of monoclonal immunoglobulins. The findings warrant a reconsideration of the role of serum free light chain concentrations and involved to uninvolved serum free light chain ratio in designation of myeloma-defining conditions and other diagnostic criteria based on serum free light chain assay.

Serum free light chain assessment in monoclonal gammopathy and kidney disease

2009 ◽  
Vol 5 (11) ◽  
pp. 621-628 ◽  
Author(s):  
Colin A. Hutchison ◽  
Kolitha Basnayake ◽  
Paul Cockwell
Keyword(s):  
Kidney Disease ◽  
Light Chain ◽  
Monoclonal Gammopathy ◽  
Free Light Chain ◽  
Serum Free ◽  
Serum Free Light Chain

Elimination of the Need for Urine Studies during Diagnostic Studies of Monoclonal Gammopathies by the Combined Use of Serum Immunofixation and Serum Free Light Chain Assays.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 5011-5011
Author(s):  
Jerry A. Katzmann ◽  
Angela Dispenzieri ◽  
Robert Kyle ◽  
Melissa R. Snyder ◽  
Mathew F. Plevak ◽  
...  
Keyword(s):  
Light Chain ◽  
Monoclonal Gammopathy ◽  
Diagnostic Algorithm ◽  
Protein Electrophoresis ◽  
Free Light Chain ◽  
Urine Protein ◽  
Serum Free ◽  
Monoclonal Gammopathies ◽  
Serum Free Light Chain ◽  
Monoclonal Proteins

Abstract Due to the diagnostic sensitivity of serum free light chain quantitation for monoclonal light chain diseases, it has been suggested that urine assays no longer need be performed as part of the diagnostic algorithm for monoclonal proteins. We reviewed our experience to determine the relative diagnostic contribution of urine assays. Methods: Patients with a monoclonal gammopathy and monoclonal urinary protein at initial diagnosis who also had a serum immunofixation and serum free light chain quantitation within 30 days of diagnosis were identified (n = 428). The laboratory results for serum protein electrophoresis, serum immunofixation, serum free light chain, urine protein electrophoresis, and urine immunofixation were reviewed. Results: The patients in this cohort had diagnoses of multiple myeloma, primary amyloid, monoclonal gammopathy of undetermined significance, smoldering multiple myeloma, solitary plasmacytomas, and other less frequently detected monoclonal gammopathies. By definition of the cohort, all 428 had a monoclonal urine protein. 86% had an abnormal serum free light chain K/L ratio, 81% had an abnormal serum protein electrophoresis, and 94% had an abnormal serum immunofixation. In only 2 patients, however, were all 3 serum assays normal. Both of these were patients with monoclonal gammopathy of undetermined significance (idiopathic Bence Jones proteinuria). Conclusion: Discontinuation of urine studies and reliance on a diagnostic algorithm using solely serum studies (protein electrophoresis, immunofixation, and free light chain quantitation), missed 2 of the 428 monoclonal gammopathies (0.5 %) with urinary monoclonal proteins, and these 2 cases required no medical intervention.

scholarly journals Serum free light chain assay reduces the need for serum and urine immunofixation electrophoresis in the evaluation of monoclonal gammopathy

2009 ◽  
Vol 46 (5) ◽  
pp. 407-412 ◽  
Author(s):  
Richard B Fulton ◽  
Suran L Fernando
Keyword(s):  
Light Chain ◽  
Monoclonal Gammopathy ◽  
Free Light Chain ◽  
Light Chains ◽  
Serum Free ◽  
Monoclonal Protein ◽  
Serum Free Light Chain ◽  
Immunofixation Electrophoresis ◽  
Monoclonal Proteins ◽  
Testing Algorithm

Background The potential for serum free light chain (sFLC) assay measurements to replace urine electrophoresis (uEPG) and to also diminish the need for serum immunofixation (sIFE) in the screening for monoclonal gammopathy was assessed. A testing algorithm for monoclonal protein was developed based on our data and cost analysis. Methods Data from 890 consecutive sFLC requests were retrospectively analysed. These included 549 samples for serum electrophoresis (sEPG), 447 for sIFE, and 318 for uEPG and urine immunofixation (uIFE). A total of 219 samples had sFLC, sEPG, sIFE and uEPG + uIFE performed. The ability of different test combinations to detect the presence of monoclonal proteins was compared. Results The sFLC κ/ λ ratio (FLC ratio) indicated monoclonal light chains in 12% more samples than uEPG + uIFE. The combination of sEPG and FLC ratio detected monoclonal proteins in 49% more samples than the combination of sEPG and sIFE. Furthermore, the sEPG + FLC ratio combination detected monoclonal protein in 6% more samples than were detected by the combined performance of sEPG, sIFE, uEPG and uIFE. However, non-linearity of the assay, the expense of repeat determinations due to the narrow measuring ranges, and frequent antigen excess checks were found to be limitations of the sFLC assay in this study. Conclusion The FLC ratio is a more sensitive method than uIFE in the detection of monoclonal light chains and may substantially reduce the need for onerous 24 h urine collections. Our proposed algorithm for the evaluation of monoclonal gammopathy incorporates the sFLC assay, resulting in a reduction in the performance of labour intensive sIFE and uEPG + uIFE while still increasing the detection of monoclonal proteins.

scholarly journals Evaluation of Correlation between Serum Free Light-Chain Assay and Bone Marrow Study in Multiple Myeloma Patients

2021 ◽  
Author(s):  
Fatemeh Zamani ◽  
Mansoureh Shokripour ◽  
Maral Mokhtari
Keyword(s):  
Multiple Myeloma ◽  
Bone Marrow ◽  
Light Chain ◽  
Predictive Value ◽  
Monoclonal Gammopathy ◽  
Free Light Chain ◽  
Serum Free ◽  
Serum Free Light Chain ◽  
Bone Marrow Study ◽  
Sensitivity Specificity

Background: Multiple myeloma is a hematologic malignancy manifested by the secretion of abnormal immunoglobulin. Different methods have been described for diagnosis and patient response to management. Serum free light-chain assay is recently approved in the diagnosis of multiple myeloma patients. This study aimed to evaluate the diagnostic accuracy of serum free light-chain assay and its agreement to bone marrow findings. Materials and Methods: Forty-six patients with the diagnosis of multiple myeloma were enrolled in the study. The patients were grouped into newly diagnosed cases (22 patients,47.8%) and known cases who were under treatment (24 patients,52.2%). Bone marrow study was done and percentage and clonal status of plasma cells were evaluated by a combination of immunohistochemistry and flow cytometry. Free light-chain assay was done in all patients and sensitivity, specificity, positive predictive value, and negative predictive value were analyzed. Results: Thirty of 46 patients showed monoclonal plasma cell infiltration and 16 patients showed polyclonal plasma cell infiltration based on bone marrow findings. An abnormal κ/λ ratio was seen in 15(68.18%) of new cases and 16(66.6%) of known cases. Sensitivity, specificity, PPV and NPV for κ⁄λ ratio were 72.73%, 46.15%, 71%, and 50%, respectively. Conclusion: In conclusion, due to high false positive and false negative results, the presence of an abnormal serum FLC ratio was not equal to the presence of monoclonal gammopathy, and observation of a normal ratio does not exclude the presence of monoclonal gammopathy.  

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