1
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Wang Q, Andress BD, Pazdernik VMK, Larson DR, Coker JD, Dasari S, Rajkumar V, Dispenzieri A, Murray DL, Willrich MAV. Comparison of 2 Free Light Chain Assays: Performance of the Free Light Chain Ratio as a Risk Factor for MGUS Progression. Clin Chem 2024:hvae124. [PMID: 39206639 DOI: 10.1093/clinchem/hvae124] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2024] [Accepted: 07/17/2024] [Indexed: 09/04/2024]
Abstract
BACKGROUND New immunoglobulin free light chain (FLC) assays are available. Despite analytical differences, it seems possible to use free light chain ratios (FLCr) generated by different assays and apply similar cut-points for the diagnosis of multiple myeloma. It is still unknown if we can use different assays for risk stratification of patients with monoclonal gammopathy of undetermined significance (MGUS). METHODS Patients diagnosed with MGUS (N = 923) had FLC tested using a nephelometric FreeLite (Binding Site) assay on BNII instruments (Siemens) and a Sebia FLC assay (Sebia) on a DS2 ELISA analyzer (Dynex). Patients were followed up for progression to any plasma cell dyscrasia (PCD) for several decades. The Mayo MGUS risk stratification model for progression was assessed with both assays (M-spike >1.5 g/dL; non-IgG isotype and abnormal FLCr), using package insert reference intervals (RI) and a new metric called principal component 2 (PC2). RESULTS There were 94 events of progression to PCD in the cohort during a median of 38 years of follow-up. Freelite and Sebia FLC showed similar hazard ratios in the risk models for elevated FLCr. An alternative clinical decision point lower than the package insert RI was evaluated for the Sebia assay, which improved risk stratification for patients with a low FLCr. The PC2 metric showed similar performance to the FLCr in models, without superior benefit. CONCLUSIONS The Sebia ELISA-based FLC assay can be employed in an MGUS risk stratification model with similar performance to the original 2005 risk stratification model using the FreeLite assay.
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Affiliation(s)
- Qian Wang
- Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN, United States
| | - Benjamin D Andress
- Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN, United States
| | - Vanessa M K Pazdernik
- Department of Quantitative Health Sciences, Division of Clinical Trials and Biostatistics, Mayo Clinic, Rochester, MN, United States
| | - Dirk R Larson
- Department of Quantitative Health Sciences, Division of Clinical Trials and Biostatistics, Mayo Clinic, Rochester, MN, United States
| | - Jonathan D Coker
- Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN, United States
| | - Surendra Dasari
- Department of Quantitative Health Sciences, Division of Clinical Trials and Biostatistics, Mayo Clinic, Rochester, MN, United States
| | - Vincent Rajkumar
- Division of Hematology, Mayo Clinic, Rochester, MN, United States
| | | | - David L Murray
- Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN, United States
| | - Maria Alice V Willrich
- Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN, United States
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2
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Cassano Cassano R, Genovesi D, Vergaro G, Giorgetti A, Aimo A, Del Giudice ML, Galimberti S, Emdin M, Buda G. [18F]-florbetaben PET/CT is sensitive for cardiac AL amyloidosis. Eur J Clin Invest 2024:e14270. [PMID: 39021058 DOI: 10.1111/eci.14270] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/06/2024] [Revised: 06/07/2024] [Accepted: 06/11/2024] [Indexed: 07/20/2024]
Abstract
Often differential diagnosis between AL and ATTR amyloidosis is difficult. Concerning ATTR, sensitive diagnostic tool, as diphosphonate scintigraphy, was validated, instead of no imaging approach is as accurate in AL. Cardiac ultrasound and circulating biomarkers may raise the clinical suspicion but biopsy remains the only option for diagnosis. We aimed to explore the sensitivity of 18F-Florbetaben PET respect to blood tests or periumbilical fat (POF), cardiac, bone marrow (BM) or other tissues biopsies in a cohort of 33 patients.
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Affiliation(s)
| | - Dario Genovesi
- Division of Nuclear Medicine, Fondazione Toscana Gabriele Monasterio, Pisa, Italy
| | - Giuseppe Vergaro
- Division of Cardiology and Cardiovascular Medicine, Fondazione Toscana Gabriele Monasterio, Pisa, Italy
- Interdisciplinary Center for Health Sciences, Scuola Superiore Sant'Anna, Pisa, Italy
| | - Assuero Giorgetti
- Division of Nuclear Medicine, Fondazione Toscana Gabriele Monasterio, Pisa, Italy
| | - Alberto Aimo
- Division of Cardiology and Cardiovascular Medicine, Fondazione Toscana Gabriele Monasterio, Pisa, Italy
- Interdisciplinary Center for Health Sciences, Scuola Superiore Sant'Anna, Pisa, Italy
| | - Maria Livia Del Giudice
- Hematology Unit, Department of Clinical And Experimental Medicine, University of Pisa, Pisa, Italy
| | - Sara Galimberti
- Hematology Unit, Department of Clinical And Experimental Medicine, University of Pisa, Pisa, Italy
| | - Michele Emdin
- Division of Cardiology and Cardiovascular Medicine, Fondazione Toscana Gabriele Monasterio, Pisa, Italy
- Interdisciplinary Center for Health Sciences, Scuola Superiore Sant'Anna, Pisa, Italy
| | - Gabriele Buda
- Hematology Unit, Department of Clinical And Experimental Medicine, University of Pisa, Pisa, Italy
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3
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Giles HV, Karunanithi K. Performance Characteristics and Limitations of the Available Assays for the Detection and Quantitation of Monoclonal Free Light Chains and New Emerging Methodologies. Antibodies (Basel) 2024; 13:19. [PMID: 38534209 DOI: 10.3390/antib13010019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2024] [Revised: 02/26/2024] [Accepted: 03/05/2024] [Indexed: 03/28/2024] Open
Abstract
Light chain measurements form an essential component of the testing strategy for the detection and monitoring of patients with suspected and/or proven plasma cell disorders. Urine-based electrophoretic assays remain at the centre of the international guidelines for response assessment but the supplementary role of serum-free light chain (FLC) assays in response assessment and the detection of disease progression due to their increased sensitivity has been increasingly recognised since their introduction in 2001. Serum FLC assays have also been shown to be prognostic across the spectrum of plasma cell disorders and are now incorporated into risk stratification scores for patients with monoclonal gammopathy of undetermined significance (MGUS), smouldering multiple myeloma, and light chain amyloidosis (AL amyloidosis), as well as being incorporated into the criteria for defining symptomatic multiple myeloma. There are now multiple different commercially available serum FLC assays available with differing performance characteristics, which are discussed in this review, along with the implications of these for patient monitoring. Finally, newer methodologies for the identification and characterisation of monoclonal FLC, including modifications to electrophoretic techniques, mass spectrometry-based assays and Amylite, are also described along with the relevant published data available regarding the performance of each assay.
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Affiliation(s)
- Hannah V Giles
- Department of Clinical Haematology, University Hospitals Birmingham NHS Foundation Trust, Birmingham B15 2SY, UK
- Instute of Immunology and Immunotherapy, University of Birmingham, Birmingham B15 2TT, UK
| | - Kamaraj Karunanithi
- Department of Clinical Haematology, University Hospitals North Midlands NHS Trust, Royal Stoke Hospital, Newcastle Road, Stoke-on-Trent ST4 6QG, UK
- School of Medicine, Keele University, Keele, Newcastle-under-Lyme ST5 5BG, UK
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4
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Omosule CL, Hock KG, Dalton C, Scalpati A, Gronowski AM, Brants A, Farnsworth CW. Method Comparison and Workflow Differences Using the Same Free Light Chain Assay on 2 Analyzer Platforms. J Appl Lab Med 2023; 8:689-699. [PMID: 37186660 DOI: 10.1093/jalm/jfad020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2022] [Accepted: 02/13/2023] [Indexed: 05/17/2023]
Abstract
BACKGROUND The Freelite assay (The Binding Site) is utilized to quantify serum immunoglobulin free light chains (sFLC), which is crucial for diagnosing and monitoring plasma cell dyscrasias (PCDs). Using the Freelite test, we compared methods and evaluated workflow differences across two analyzer platforms. METHODS sFLC concentrations were measured in 306 fresh serum specimens (cohort A) and 48 frozen specimens with documented sFLC >20 mg/dL (cohort B). Specimens were analyzed on the Roche cobas 8000 and Optilite analyzers using the Freelite κ and λ assays. Performance was compared using Deming regression. Workflow was compared by assessing turnaround time (TAT) and reagent usage. RESULTS For cohort A specimens, Deming regression revealed a slope of 1.04 (95% CI, 0.88-1.02) and an intercept of -0.77 (95% CI, -0.57 to 1.85) for sFLCκ and a slope of 0.90 (95% CI, -0.04 to 1.83) and intercept of 1.59 (95% CI, -3.12 to 6.25) for sFLCλ. Regression of the κ/λ ratio revealed a slope of 2.44 (95% CI, 1.47-3.41) and intercept of -8.13 (95% CI, -16.82 to 0.58) with a concordance kappa of 0.80 (95% CI, 0.69-0.92). The proportion of specimens with TAT >60 min was 0.33% and 8% for the Optilite and cobas, respectively (P < 0.001). The Optilite required 49 (P < 0.001) and 12 (P = 0.016) fewer tests for sFLCκ and sFLCλ relative to the cobas. Cohort B specimens showed similar but more dramatic results. CONCLUSIONS Analytical performance of the Freelite assays was comparable on the Optilite and cobas 8000 analyzers. In our study, the Optilite required less reagent, had a slightly reduced TAT, and eliminated manual dilutions for samples with sFLC concentrations >20 mg/dL.
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Affiliation(s)
- Catherine L Omosule
- Department of Pathology & Immunology, Washington University in St. Louis School of Medicine, St. Louis, MO, United States
| | - Karl G Hock
- Department of Pathology & Immunology, Washington University in St. Louis School of Medicine, St. Louis, MO, United States
| | - Claire Dalton
- Department of Pathology & Immunology, Washington University in St. Louis School of Medicine, St. Louis, MO, United States
| | | | - Ann M Gronowski
- Department of Pathology & Immunology, Washington University in St. Louis School of Medicine, St. Louis, MO, United States
| | - Aigars Brants
- The Binding Site, Inc., San Diego, CA, United States
| | - Christopher W Farnsworth
- Department of Pathology & Immunology, Washington University in St. Louis School of Medicine, St. Louis, MO, United States
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5
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Abroud H, Beldi‐Ferchiou A, Audard V, Lemonnier F, Le Bras F, Belhadj K, Moktefi A, Poullot E, El Karoui K, Dupuis J, Maarek A, Roulin L, Delfau‐Larue M, Oghina S, Kharoubi M, Bézard M, Zaroui A, Damy T, Molinier‐Frenkel V. Evaluation of a new ELISA assay for monoclonal free-light chain detection in patients with cardiac amyloidosis. EJHAEM 2022; 3:828-837. [PMID: 36051065 PMCID: PMC9421952 DOI: 10.1002/jha2.516] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/11/2022] [Revised: 06/08/2022] [Accepted: 06/10/2022] [Indexed: 11/27/2022]
Abstract
The causal protein of amyloid light-chain (AL) amyloidosis is a monoclonal immunoglobulin free light chain (mFLC), which must be quantified in the serum for patient diagnosis and monitoring. Several manufacturers commercialize immunoassays that quantify total kappa (κ) and lambda (λ) FLC, but results can differ greatly between these tests. Here, we compared a recently developed enzyme-linked immunosorbent assay (ELISA) (Sebia) with N-Latex immunonephelometry (Siemens) in 96 patients diagnosed with AL amyloidosis (histologically confirmed) and 48 non-AL patients sent to our referral center for suspicion of cardiac amyloidosis. ELISA free-light chain difference (dFLC) were lower than N-Latex values, and agreement between methods was reduced in the case of involved λ FLC. Diagnosis sensitivity and specificity were >85% with both assays. A receiver operating characteristic analysis indicated that ELISA performances could be improved by using a higher value for the lower limit of the κ/λ ratio. We also assessed Freelite (The Binding Site) in a subgroup of these same AL patients, including 18 cases with normal κ/λ ratio by at least one assay. Only two patients had normal κ/λ ratio with all three assays. Overall, ELISA demonstrated slightly lower sensitivity than N-Latex but may be an alternative to nephelometry/turbidimetry in certain difficult cases.
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Affiliation(s)
- Hajer Abroud
- Département d'Hématologie‐ImmunologieAP‐HP, Hopital Henri MondorCreteilFrance
| | - Asma Beldi‐Ferchiou
- Département d'Hématologie‐ImmunologieAP‐HP, Hopital Henri MondorCreteilFrance
- INSERMIMRBUniv Paris Est CreteilCreteilFrance
| | - Vincent Audard
- French Referral Centre for Cardiac AmyloidosisCardiogen NetworkGRC Amyloid Research InstituteHenri Mondor HospitalCreteilFrance
- Service de Néphrologie et TransplantationAP‐HP, Hopital Henri MondorCreteilFrance
| | - François Lemonnier
- French Referral Centre for Cardiac AmyloidosisCardiogen NetworkGRC Amyloid Research InstituteHenri Mondor HospitalCreteilFrance
- Unité Hémopathies LymphoïdesAP‐HP, Hopital Henri MondorCreteilFrance
| | - Fabien Le Bras
- French Referral Centre for Cardiac AmyloidosisCardiogen NetworkGRC Amyloid Research InstituteHenri Mondor HospitalCreteilFrance
- Unité Hémopathies LymphoïdesAP‐HP, Hopital Henri MondorCreteilFrance
| | - Karim Belhadj
- French Referral Centre for Cardiac AmyloidosisCardiogen NetworkGRC Amyloid Research InstituteHenri Mondor HospitalCreteilFrance
- Unité Hémopathies LymphoïdesAP‐HP, Hopital Henri MondorCreteilFrance
| | - Anissa Moktefi
- French Referral Centre for Cardiac AmyloidosisCardiogen NetworkGRC Amyloid Research InstituteHenri Mondor HospitalCreteilFrance
- Département de PathologieAP‐HP, Hopital Henri MondorCreteilFrance
| | - Elsa Poullot
- French Referral Centre for Cardiac AmyloidosisCardiogen NetworkGRC Amyloid Research InstituteHenri Mondor HospitalCreteilFrance
- Département de PathologieAP‐HP, Hopital Henri MondorCreteilFrance
| | - Khalil El Karoui
- French Referral Centre for Cardiac AmyloidosisCardiogen NetworkGRC Amyloid Research InstituteHenri Mondor HospitalCreteilFrance
- Service de Néphrologie et TransplantationAP‐HP, Hopital Henri MondorCreteilFrance
| | - Jehan Dupuis
- French Referral Centre for Cardiac AmyloidosisCardiogen NetworkGRC Amyloid Research InstituteHenri Mondor HospitalCreteilFrance
- Unité Hémopathies LymphoïdesAP‐HP, Hopital Henri MondorCreteilFrance
| | - Alizée Maarek
- French Referral Centre for Cardiac AmyloidosisCardiogen NetworkGRC Amyloid Research InstituteHenri Mondor HospitalCreteilFrance
- Unité Hémopathies LymphoïdesAP‐HP, Hopital Henri MondorCreteilFrance
| | - Louise Roulin
- French Referral Centre for Cardiac AmyloidosisCardiogen NetworkGRC Amyloid Research InstituteHenri Mondor HospitalCreteilFrance
- Unité Hémopathies LymphoïdesAP‐HP, Hopital Henri MondorCreteilFrance
| | - Marie‐Hélène Delfau‐Larue
- Département d'Hématologie‐ImmunologieAP‐HP, Hopital Henri MondorCreteilFrance
- INSERMIMRBUniv Paris Est CreteilCreteilFrance
| | - Silvia Oghina
- French Referral Centre for Cardiac AmyloidosisCardiogen NetworkGRC Amyloid Research InstituteHenri Mondor HospitalCreteilFrance
- Département de CardiologieAP‐HP, Hopital Henri MondorCreteilFrance
| | - Mounira Kharoubi
- French Referral Centre for Cardiac AmyloidosisCardiogen NetworkGRC Amyloid Research InstituteHenri Mondor HospitalCreteilFrance
- Département de CardiologieAP‐HP, Hopital Henri MondorCreteilFrance
| | - Mélanie Bézard
- French Referral Centre for Cardiac AmyloidosisCardiogen NetworkGRC Amyloid Research InstituteHenri Mondor HospitalCreteilFrance
- Département de CardiologieAP‐HP, Hopital Henri MondorCreteilFrance
| | - Amira Zaroui
- French Referral Centre for Cardiac AmyloidosisCardiogen NetworkGRC Amyloid Research InstituteHenri Mondor HospitalCreteilFrance
- Département de CardiologieAP‐HP, Hopital Henri MondorCreteilFrance
| | - Thibaud Damy
- French Referral Centre for Cardiac AmyloidosisCardiogen NetworkGRC Amyloid Research InstituteHenri Mondor HospitalCreteilFrance
- Département de CardiologieAP‐HP, Hopital Henri MondorCreteilFrance
- INSERM, IMRB, CEPiaAUniv Paris Est CreteilCreteilFrance
| | - Valérie Molinier‐Frenkel
- Département d'Hématologie‐ImmunologieAP‐HP, Hopital Henri MondorCreteilFrance
- INSERMIMRBUniv Paris Est CreteilCreteilFrance
- French Referral Centre for Cardiac AmyloidosisCardiogen NetworkGRC Amyloid Research InstituteHenri Mondor HospitalCreteilFrance
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6
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Van Hoovels L, Vercammen M, Nevejan L, Cornette M, Briers PJ, Deeren D, Van Droogenbroeck J, Fostier K, De Smet D. Serum free light chain analysis: persisting limitations with new kids on the block. Clin Chem Lab Med 2022; 60:1440-1448. [PMID: 35781357 DOI: 10.1515/cclm-2022-0347] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2022] [Accepted: 06/21/2022] [Indexed: 11/15/2022]
Abstract
OBJECTIVES Serum free light chain (sFLC) measurements have inherent analytical limitations impacting sFLC clinical interpretation. We evaluated analytical and diagnostic performance of three polyclonal sFLC assays on four analytical platforms. METHODS sFLC concentration was measured using Diazyme FLC assays (Diazyme) on cobas c501/c503 analyzer (Roche); Freelite assays (The Binding Site) on Optilite analyzer (The Binding Site) and cobas c501 analyzer and Sebia FLC ELISA assays (Sebia) on AP22 ELITE analyzer (DAS). Imprecision, linearity, method comparison vs. Freelite/Optilite, antigen excess detection and reference value verification were assessed. Diagnostic performance was compared on 120 serum samples and on follow-up samples of five patients with κ and λ monoclonal gammopathy. RESULTS Method comparison showed excellent correlation with Freelite/Optilite method for all assays. A large proportional negative bias was shown for both Sebia κ and λ ELISA and a significant positive proportional bias for λ in the low (<10 mg/L) Freelite/cobas c501 method. Clinically relevant underestimation of κ sFLC levels due to antigen excess was shown for 7% of each Diazyme/cobas application and for 11 and 32.1% of λ sFLC assay of respectively Diazyme/cobas and Sebia/AP22. sFLC reference values revealed application specific. Cohen's κ values were (very) good for κ sFLC but only moderate to good for λ sFLC. In 4/10 follow-up patients, significant differences in clinical interpretation between sFLC assays were noticed. CONCLUSIONS Important analytical limitations remain for all sFLC applications. Differences in reference values and diagnostic performance hamper interchangeability of sFLC assays. Assay specific sFLC decision guidelines are warranted.
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Affiliation(s)
- Lieve Van Hoovels
- Department of Laboratory Medicine, OLV Hospital Aalst, Aalst, Belgium.,Department of Microbiology, Immunology and Transplantation, KU Leuven, Leuven, Belgium
| | - Martine Vercammen
- Department of Laboratory Medicine, AZ Sint-Jan Hospital Brugge - Oostende AV, Bruges, Belgium.,Research group REIM, Vrije Universiteit Brussel (VUB), Brussels, Belgium
| | - Louis Nevejan
- Department of Laboratory Medicine, OLV Hospital Aalst, Aalst, Belgium.,Department of Laboratory Medicine, University Hospital Leuven, Leuven, Belgium
| | - Margot Cornette
- Department of Laboratory Medicine, AZ Delta Hospital, Roeselare, Belgium.,Department of Laboratory Medicine, University Hospital Ghent, Ghent, Belgium
| | - Pieter-Jan Briers
- Department of Laboratory Medicine, AZ Sint-Jan Hospital Brugge - Oostende AV, Bruges, Belgium.,Department of Laboratory Medicine, University Hospital Leuven, Leuven, Belgium
| | - Dries Deeren
- Department of Hematology, AZ Delta Hospital, Roeselare, Belgium
| | - Jan Van Droogenbroeck
- Department of Hematology, AZ Sint-Jan Hospital Brugge - Oostende AV, Bruges, Belgium
| | - Karel Fostier
- Department of Hematology, OLV Hospital, Aalst, Belgium
| | - Dieter De Smet
- Department of Laboratory Medicine, AZ Delta Hospital, Roeselare, Belgium
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7
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Zhu G, Fu X, Ren Y, Wang Y, Wang S, An G. Comparative analysis of three serum‐free light‐chain detection systems in the diagnosis of multiple myeloma. Int J Lab Hematol 2022; 44:576-581. [DOI: 10.1111/ijlh.13790] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2021] [Revised: 11/02/2021] [Accepted: 12/02/2021] [Indexed: 11/27/2022]
Affiliation(s)
- Guoqing Zhu
- State Key Laboratory of Experimental Hematology, National Clinical Research Center for Blood Diseases, Haihe Laboratory of Cell Ecosystem, Institute of Hematology & Blood Diseases Hospital Chinese Academy of Medical Sciences & Peking Union Medical College Tianjin China
| | - Xue Fu
- State Key Laboratory of Experimental Hematology, National Clinical Research Center for Blood Diseases, Haihe Laboratory of Cell Ecosystem, Institute of Hematology & Blood Diseases Hospital Chinese Academy of Medical Sciences & Peking Union Medical College Tianjin China
| | - Yansong Ren
- State Key Laboratory of Experimental Hematology, National Clinical Research Center for Blood Diseases, Haihe Laboratory of Cell Ecosystem, Institute of Hematology & Blood Diseases Hospital Chinese Academy of Medical Sciences & Peking Union Medical College Tianjin China
| | - Yansheng Wang
- State Key Laboratory of Experimental Hematology, National Clinical Research Center for Blood Diseases, Haihe Laboratory of Cell Ecosystem, Institute of Hematology & Blood Diseases Hospital Chinese Academy of Medical Sciences & Peking Union Medical College Tianjin China
| | - Shoulei Wang
- State Key Laboratory of Experimental Hematology, National Clinical Research Center for Blood Diseases, Haihe Laboratory of Cell Ecosystem, Institute of Hematology & Blood Diseases Hospital Chinese Academy of Medical Sciences & Peking Union Medical College Tianjin China
| | - Gang An
- State Key Laboratory of Experimental Hematology, National Clinical Research Center for Blood Diseases, Haihe Laboratory of Cell Ecosystem, Institute of Hematology & Blood Diseases Hospital Chinese Academy of Medical Sciences & Peking Union Medical College Tianjin China
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8
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Morales-García LJ, Pacheco-Delgado MS. Serum free light chain reference intervals in an Optilite and their influence on clinical guidelines. Clin Biochem 2021; 92:54-60. [PMID: 33662349 DOI: 10.1016/j.clinbiochem.2021.02.008] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2020] [Revised: 01/26/2021] [Accepted: 02/16/2021] [Indexed: 11/17/2022]
Abstract
BACKGROUND Serum free light chain (FLC) analysis has been incorporated into the International Myeloma Working Group guidelines for the diagnosis and management of all monoclonal gammopathies. These recommendations were solely based on a single assay method (Freelite assay) and instrument. Here, we establish new reference intervals (RIs) for kappa and lambda FLC and the kappa-lambda difference and sum and a new diagnostic range for kappa/lambda FLC ratio (K/L-FLC) in an Optilite turbidimeter (The Binding Site) with the Freelite assay. METHODS To establish new RIs, the CLSI EP28-A3C protocol was applied to 249 sample blood donors from Fuenlabrada, Spain, and the central 95% and total range were estimated. Samples from patients with polyclonal hypo- and hypergammaglobulinemia were used for the evaluation of K/L-FLC as a monoclonal proliferation index. RESULTS The new RIs and the new K/L-FLC diagnostic range for the Optilite (0.65-2.56 mg/L) are very different from those in on the guidelines (0.26-1.65 mg/L). We propose new RIs for the K - L difference and the K + L sum. Diagnostic range validation as a monoclonal proliferation index with samples with hypo- and hypergammaglobulinemia confirms this new range. CONCLUSIONS In this study, we present the FLC RI for Freelite reagents measured on an Optilite turbidimeter. These ranges are different from those provided by the manufacturer and from those used in most studies in the literature, which may lead to patient misclassification. Manufacturers and clinical laboratories must strive to provide RIs for the technology they are using and for their population.
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Affiliation(s)
- Luis J Morales-García
- Department of Clinical Laboratory, Hospital Universitario de Fuenlabrada, Camino del Molino 2, Fuenlabrada, Madrid 28942, Spain.
| | - María S Pacheco-Delgado
- Department of Clinical Laboratory, Hospital Universitario de Fuenlabrada, Camino del Molino 2, Fuenlabrada, Madrid 28942, Spain.
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9
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Moreau C, Lefevre CR, Decaux O. How to quantify monoclonal free light chains in plasma cell disorders: which mass spectrometry technology? ANNALS OF TRANSLATIONAL MEDICINE 2020; 8:973. [PMID: 32953773 PMCID: PMC7475393 DOI: 10.21037/atm.2020.03.200] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Caroline Moreau
- Biochemistry Laboratory, Pontchaillou Hospital CHU Rennes, Rennes, France.,Univ Rennes, CHU Rennes, INSERM, EHESP, IRSET (Institut de Recherche en Santé, Environment et Travail) UMR_S 1085, Rennes, France
| | - Charles R Lefevre
- Biochemistry Laboratory, Pontchaillou Hospital CHU Rennes, Rennes, France.,Univ Rennes, CHU Rennes, INSERM, EHESP, IRSET (Institut de Recherche en Santé, Environment et Travail) UMR_S 1085, Rennes, France
| | - Olivier Decaux
- Internal Medicine, CHU Rennes, Rennes, France.,Hematology, Pontchaillou Hospital CHU Rennes, Rennes, France
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10
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Schieferdecker A, Hörber S, Ums M, Besemer B, Bokemeyer C, Peter A, Weisel K. Comparison of three different serum-free light-chain assays-implications on diagnostic and therapeutic monitoring of multiple myeloma. Blood Cancer J 2020; 10:2. [PMID: 31915365 PMCID: PMC6949235 DOI: 10.1038/s41408-019-0267-8] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2019] [Revised: 11/19/2019] [Accepted: 11/25/2019] [Indexed: 11/09/2022] Open
Abstract
The measurement of serum-free light chains (FLC) is standard of care in the diagnosis and management of multiple myeloma (MM). The revised international myeloma working group (IMWG) implemented the involved FLC/noninvolved FLC (iFLC/niFLC) ratio as a biomarker for MM requiring treatment. Recently, a new definition of high-risk smoldering MM (SMM) including iFLC/niFLC ratio was published. These recommendations were solely based on a single assay method (Freelite assay). Today, two additional assays, N Latex FLC and ELISA-based Sebia FLC, are available. Here, we report on a single-center-study comparing results of all three different assays for FLC correlation and its potential implications for diagnostic and clinical use. In total, 187 samples from 47 MM patients were examined, and determination of FLC was performed. Comparison analyses showed similar FLC results for Sebia FLC and N Latex FLC assay with markedly lower absolute values for κ/λ ratio compared with Freelite. Values of λ FLC exhibited high variability. The ratio of iFLC/niFLC showed significant discrepancies among these assays. Our data demonstrate that the three available assays may result in markedly discrepant results, and should not be used interchangeably to monitor patients. Furthermore, modifications of the assay-specific diagnostic (iFLC/niFLC) thresholds for SMM and MM are recommended.
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Affiliation(s)
- Aneta Schieferdecker
- Department of Oncology and Hematology, BMT with Department of Pneumology, Hubertus Wald Tumorzentrum, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Sebastian Hörber
- Institute for Clinical Chemistry and Pathobiochemistry, Department for Diagnostic Laboratory Medicine, University Hospital Tuebingen, Tuebingen, Germany.,Institute for Diabetes Research and Metabolic Diseases of the Helmholtz Center Munich at the University of Tuebingen, Tuebingen, Germany.,German Center for Diabetes Research (DZD), München-Neuherberg, Germany
| | - Monika Ums
- Center of Clinical Trials (ZKS) Tübingen, University Hospital of Tuebingen, Tuebingen, Germany
| | - Britta Besemer
- Department of Hematology, Oncology, Immunology and Rheumatology, University Hospital of Tuebingen, Tuebingen, Germany
| | - Carsten Bokemeyer
- Department of Oncology and Hematology, BMT with Department of Pneumology, Hubertus Wald Tumorzentrum, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Andreas Peter
- Institute for Clinical Chemistry and Pathobiochemistry, Department for Diagnostic Laboratory Medicine, University Hospital Tuebingen, Tuebingen, Germany.,Institute for Diabetes Research and Metabolic Diseases of the Helmholtz Center Munich at the University of Tuebingen, Tuebingen, Germany.,German Center for Diabetes Research (DZD), München-Neuherberg, Germany
| | - Katja Weisel
- Department of Oncology and Hematology, BMT with Department of Pneumology, Hubertus Wald Tumorzentrum, University Medical Center Hamburg-Eppendorf, Hamburg, Germany. .,Department of Hematology, Oncology, Immunology and Rheumatology, University Hospital of Tuebingen, Tuebingen, Germany.
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11
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Fleming CK, Swarttouw T, de Kat Angelino CM, Jacobs JF, Russcher H. Method comparison of four clinically available assays for serum free light chain analysis. ACTA ACUST UNITED AC 2019; 58:85-94. [DOI: 10.1515/cclm-2019-0533] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2019] [Accepted: 07/29/2019] [Indexed: 12/22/2022]
Abstract
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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Affiliation(s)
- Chérina K.A. Fleming
- Department of Clinical Chemistry, Erasmus MC , University Medical Center Rotterdam , Rotterdam , The Netherlands
| | - Tim Swarttouw
- Department of Clinical Chemistry, Erasmus MC , University Medical Center Rotterdam , Rotterdam , The Netherlands
| | | | - Joannes F.M. Jacobs
- Department of Laboratory Medicine , Radboud University Medical Center , Nijmegen , The Netherlands
| | - Henk Russcher
- Department of Clinical Chemistry, Erasmus MC , University Medical Center Rotterdam , Rotterdam , The Netherlands
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12
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Caponi L, Romiti N, Koni E, Fiore AD, Paolicchi A, Franzini M. Inter-assay variability in automated serum free light chain assays and their use in the clinical laboratory. Crit Rev Clin Lab Sci 2019; 57:73-85. [PMID: 31612753 DOI: 10.1080/10408363.2019.1670133] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Serum κ and λ free light chain levels are markers of plasma cell proliferation, and their measurements have been included in recent guidelines by the International Myeloma Working Group for the management of patients with plasma cellular dyscrasias. Five in vitro diagnostic methods for the immunochemical quantification of serum free light chains (FLC) are available, three based on polyclonal antibodies (Freelite®, The Binding Site; FLC ELISA κ and λ, Sebia; human κ and λ FLC, Diazyme Laboratories) and two on monoclonal antibodies (N Latex FLC, Siemens Healthineers; Seralite®, Sebia). Several studies have shown that these methods cannot be used interchangeably for the follow-up of patients because measured κ and λ FLC concentrations may differ significantly, especially at high levels. Because no international reference material for the measurement of FLC is available, it is not possible to establish which method is the most accurate. For this reason, knowledge about the analytical and diagnostic performances of the assays used is important. The aim of this review is to describe the main analytical features of the κ and λ FLC assays and how they may influence the clinical use of these parameters.
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Affiliation(s)
- Laura Caponi
- Department of Translational Research and New Technologies in Medicine, University of Pisa, Pisa, Italy
| | - Nadia Romiti
- Department of Translational Research and New Technologies in Medicine, University of Pisa, Pisa, Italy
| | - Elona Koni
- Department of Translational Research and New Technologies in Medicine, University of Pisa, Pisa, Italy
| | - Annarita Di Fiore
- Department of Translational Research and New Technologies in Medicine, University of Pisa, Pisa, Italy
| | - Aldo Paolicchi
- Department of Translational Research and New Technologies in Medicine, University of Pisa, Pisa, Italy
| | - Maria Franzini
- Department of Translational Research and New Technologies in Medicine, University of Pisa, Pisa, Italy
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