scholarly journals Serum free light chain assays not total light chain assays are the standard of care to assess Monoclonal Gammopathies

2016 ◽  
Vol 38 (1) ◽  
pp. 37-43 ◽  
Author(s):  
Vania Tietsche de Moraes Hungria ◽  
Syreeta Allen ◽  
Petros Kampanis ◽  
Elyara Maria Soares
2019 ◽  
Vol 9 (6) ◽  
Author(s):  
Shaji Kumar ◽  
Dirk R. Larson ◽  
Angela Dispenzieri ◽  
Terry M. Therneau ◽  
David L. Murray ◽  
...  

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 5011-5011
Author(s):  
Jerry A. Katzmann ◽  
Angela Dispenzieri ◽  
Robert Kyle ◽  
Melissa R. Snyder ◽  
Mathew F. Plevak ◽  
...  

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.


Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 4750-4750
Author(s):  
Fernanda Trigo ◽  
Cristina Guimaraes ◽  
Abilia Bodas ◽  
Armando Teixeira-Pinto ◽  
Jose E. Guimaraes

Abstract Serum free light chain (FLC) levels are a useful multiple myeloma (MM) marker and a indicator of tumour burden both for diagnosis and follow up purposes. A total of 311 patient samples were assayed in our laboratory for FLC and the kappa/lambda (κ/λ) chain ratio was calculated and compared with the classical methods for characterization of gammopathy (immunofixation, IMF, immunoglobulin levels and total light chain levels and respective ratio). Ig (A, G, M) and total κ and λ chain levels were assayed by nephlometry (Dade-Behring BNII). Immunofixation was performed in a Hydrasys (Sebia) setting. FLC assay was done using Binding Site reagents (Dade-Behring). Statistical analysis was performed by SPSS® for Windows v. 15. Concordance between IMF results and free κ/λ chain ratio was calculated. Sensitivity and specificity of the free κ/λ chain ratio in the identification of positive and negative IMF were also determined. Reference intervals used for free κ/λ and total κ/λ chain ratios were [0.26; 1.65] and [1.35; 2.65], respectively. Out of 311 patients with gammopathy studied, 235 had absence of monoclonality as defined by the immunoelectrophoretic profile. Inclusively, only 51% of the 53 patients with suspected MM and 66% of the 41 patients with a diagnosis of MGUS were IMF positive. Sensitivity and specificity of total κ/λ chain ratio for identification of positive or negative IMF were respectively 70% and 91% with a global concordance of 86%. In 215 (70%) patients, IMF and free κ/λ chain ratio were in agreement. However, 74 (32%) of IMF negative patients had abnormal free κ/λ chain ratio: 18% had a final diagnosis of chronic renal failure, 13% of CLL or NHL, 9% of MGUS, 7% of MM and 3% of amyloidosis; the remainder 50% were diagnosed as having a disease other than lymphoplasmacytic disorder. These results stress the value of free light chain determination in the diagnosis and follow up of gammopathies and its usefulness as a marker for multiple myeloma and associated monoclonal gammopathies.


2020 ◽  
Vol 5 (6) ◽  
pp. 1358-1371
Author(s):  
Gurmukh Singh

Abstract Background Laboratory methods for diagnosis and monitoring of monoclonal gammopathies have evolved to include serum and urine protein electrophoresis, immunofixation electrophoresis, capillary zone electrophoresis, and immunosubtraction, serum-free light chain assay, mass spectrometry, and newly described QUIET. Content This review presents a critical appraisal of the test methods and reporting practices for the findings generated by the tests for monoclonal gammopathies. Recommendations for desirable practices to optimize test selection and provide value-added reports are presented. The shortcomings of the serum-free light chain assay are highlighted, and new assays for measuring monoclonal serum free light chains are addressed. Summary The various assays for screening, diagnosis, and monitoring of monoclonal gammopathies should be used in an algorithmic approach to avoid unnecessary testing. Reporting of the test results should be tailored to the clinical context of each individual patient to add value. Caution is urged in the interpretation of results of serum-free light chain assay, kappa/lambda ratio, and myeloma defining conditions. The distortions in serum-free light chain assay and development of oligoclonal bands in patients‘ status post hematopoietic stem cell transplants is emphasized and the need to note the location of original monoclonal Ig is stressed. The need for developing criteria that consider the differences in the biology of kappa and lambda light chain associated lesions is stressed. A new method of measuring monoclonal serum-free light chains is introduced. Reference is also made to a newly defined entity of light chain predominant intact immunoglobulin monoclonal gammopathy. The utility of urine testing in the diagnosis and monitoring of light chain only lesions is emphasized.


2019 ◽  
Vol 58 (1) ◽  
pp. 85-94
Author(s):  
Chérina K.A. Fleming ◽  
Tim Swarttouw ◽  
Corrie M. de Kat Angelino ◽  
Joannes F.M. Jacobs ◽  
Henk Russcher

Abstract Background Serum free light chain (sFLC) measurements are increasingly important in the context of screening for monoclonal gammopathies, prognostic stratification and monitoring of therapy responses. In this study we have performed a method comparison of four sFLC assays that are currently available for routine clinical use. Methods In a retrospective study, sFLC analyses were performed on a cohort that included 139 patients with various monoclonal gammopathies and 54 control sera without an M-protein. Method comparisons of the following four FLC assays were performed: Freelite (Binding Site), N-Latex FLC (Siemens), Seralite (Abingdon Health) and Sebia FLC (Sebia). Results Bland-Altman agreement analysis showed biases varying between −0.1 and 16.2 mg/L for κFLC, −6.0 and 6.8 mg/L for λFLC and −0.04 and 0.38 for the ratio of the involved to uninvolved FLC. Strong agreements were observed for FLC-concentrations below 100 mg/L. The clinical concordance of the κ/λFLC-ratio of the four methods varied between 86% and 92%. Significant quantitative differences were observed between the different methods, mainly in sera with high FLC concentrations. Most assays consistently overestimated FLC concentrations compared to SPE. Conclusions Good overall clinical concordances were observed between the four sFLC assays that were compared in this study. Although good agreements were observed between the FLC assays, significant absolute differences in FLC concentrations in individual patients can be seen, particularly at higher FLC concentrations. Because of inequivalent absolute sFLC values between the methods in individual patients, none of the four sFLC assays can be used interchangeably.


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