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Ma Y, Wang D, Li H, Ma X, Zou Y, Mu D, Cheng X, Qiu L, Yu S. Liquid chromatography-tandem mass spectrometry in clinical laboratory protein measurement. Clin Chim Acta 2024:119846. [PMID: 38969085 DOI: 10.1016/j.cca.2024.119846] [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: 03/17/2024] [Revised: 06/30/2024] [Accepted: 07/02/2024] [Indexed: 07/07/2024]
Abstract
Proteins are essential components of human cells and tissues, and they are commonly measured in clinical laboratories using immunoassays. However, these assays have certain limitations, such as non-specificity binding, insufficient selectivity, and interference of antibodies. More sensitive, accurate, and efficient technology is required to overcome these limitations. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) is a powerful analytical tool that provides high sensitivity and specificity, making it superior to traditional methods such as biochemical and immunoassays. While LC-MS/MS has been increasingly used for detecting small molecular analytes and steroid hormones in clinical practice recently, its application for protein or peptide analysis is still in its early stages. Established methods for quantifying proteins and peptides by LC-MS/MS are mainly focused on scientific research, and only a few proteins and peptides can be or have the potential to be detected and applied in clinical practice. Therefore, this article aims to review the clinical applications, advantages, and challenges of analyzing proteins and peptides using LC-MS/MS in clinical laboratories.
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Affiliation(s)
- Yichen Ma
- Department of Laboratory Medicine, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, No. 1 Shuaifu Yuan, Dongcheng District, Beijing 100730, China
| | - Danchen Wang
- Department of Laboratory Medicine, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, No. 1 Shuaifu Yuan, Dongcheng District, Beijing 100730, China
| | - Honglei Li
- Department of Laboratory Medicine, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, No. 1 Shuaifu Yuan, Dongcheng District, Beijing 100730, China
| | - Xiaoli Ma
- Department of Laboratory Medicine, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, No. 1 Shuaifu Yuan, Dongcheng District, Beijing 100730, China
| | - Yutong Zou
- Department of Laboratory Medicine, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, No. 1 Shuaifu Yuan, Dongcheng District, Beijing 100730, China
| | - Danni Mu
- Department of Laboratory Medicine, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, No. 1 Shuaifu Yuan, Dongcheng District, Beijing 100730, China
| | - Xinqi Cheng
- Department of Laboratory Medicine, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, No. 1 Shuaifu Yuan, Dongcheng District, Beijing 100730, China.
| | - Ling Qiu
- Department of Laboratory Medicine, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, No. 1 Shuaifu Yuan, Dongcheng District, Beijing 100730, China; State Key Laboratory of Complex Severe and Rare Diseases, Peking Union Medical College Hospital, Chinese Academy of Medical Science and Peking Union Medical College, Beijing 100730, China.
| | - Songlin Yu
- Department of Laboratory Medicine, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, No. 1 Shuaifu Yuan, Dongcheng District, Beijing 100730, China.
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Tang C, Verwilligen A, Sadoff J, Brandenburg B, Sneekes-Vriese E, van den Kerkhof T, Dillen L, Rutten L, Juraszek J, Callewaert K, Janssen S, Huizingh J, Euler Z, Schilperoord T, Verhemeldonck M, Langedijk JPM, Hendriks J, Stieh DJ. Absolute quantitation of binding antibodies from clinical samples. NPJ Vaccines 2024; 9:8. [PMID: 38184641 PMCID: PMC10771429 DOI: 10.1038/s41541-023-00793-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2023] [Accepted: 12/08/2023] [Indexed: 01/08/2024] Open
Abstract
The quantitation of antibody responses is a critical requirement for the successful development of vaccines and therapeutics that often relies on the use of standardized reference materials to determine relative quantities within biological samples. The validity of comparing responses across assays using arbitrarily defined reference values is therefore limited. We developed a generalizable method known as MASCALE (Mass Spectrometry Enabled Conversion to Absolute Levels of ELISA Antibodies) for absolute quantitation of antibodies by calibrating ELISA reference sera using mass spectrometry. Levels of proteotypic peptides served as a proxy for human IgG, allowing the conversion of responses from arbitrary values to absolute amounts. Applications include comparison of binding assays at two separate laboratories and evaluation of cross-clade magnitude-breadth responses induced by an investigational HIV-1 vaccine regimen. MASCALE addresses current challenges in the interpretation of immune responses in clinical trials and expands current options available to make suitable comparisons across different settings.
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Affiliation(s)
- Chan Tang
- Janssen Vaccines & Prevention, Leiden, The Netherlands
| | | | - Jerald Sadoff
- Janssen Vaccines & Prevention, Leiden, The Netherlands
| | | | | | | | | | - Lucy Rutten
- Janssen Vaccines & Prevention, Leiden, The Netherlands
| | | | | | - Sarah Janssen
- Janssen Vaccines & Prevention, Leiden, The Netherlands
| | | | - Zelda Euler
- Janssen Vaccines & Prevention, Leiden, The Netherlands
| | | | | | | | | | - Daniel J Stieh
- Janssen Vaccines & Prevention, Leiden, The Netherlands.
- Vaccine Company, Inc., South San Francisco, CA, USA.
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Pérez-Escurza O, Flores-Montero J, Óskarsson JÞ, Sanoja-Flores L, Del Pozo J, Lecrevisse Q, Martín S, Reed ER, Hákonardóttir GK, Harding S, Þorsteinsdóttir S, Rögnvaldsson S, Love TJ, Durie B, Kristinsson SY, Orfao A. Immunophenotypic assessment of clonal plasma cells and B-cells in bone marrow and blood in the diagnostic classification of early stage monoclonal gammopathies: an iSTOPMM study. Blood Cancer J 2023; 13:182. [PMID: 38072838 PMCID: PMC10711003 DOI: 10.1038/s41408-023-00944-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2023] [Revised: 10/26/2023] [Accepted: 11/03/2023] [Indexed: 12/18/2023] Open
Abstract
Monoclonal gammopathy of undetermined significance (MGUS) is the earliest discernible stage of multiple myeloma (MM) and Waldenström's macroglobulinemia (WM). Early diagnosis of MG may be compromised by the low-level infiltration, undetectable to low-sensitive methodologies. Here, we investigated the prevalence and immunophenotypic profile of clonal (c) plasma cells (PC) and/or cB-lymphocytes in bone marrow (BM) and blood of subjects with a serum M-component from the iSTOPMM program, using high-sensitive next-generation flow cytometry (NGF), and its utility in the diagnostic classification of early-stage MG. We studied 164 paired BM and blood samples from 82 subjects, focusing the analysis on: 55 MGUS, 12 smoldering MM (SMM) and 8 smoldering WM (SWM). cPC were detected in 84% of the BM samples and cB-lymphocytes in 45%, coexisting in 39% of cases. In 29% of patients, the phenotypic features of cPC and/or cB-lymphocytes allowed a more accurate disease classification, including: 19/55 (35%) MGUS, 1/12 (8%) SMM and 2/8 (25%) SWM. Blood samples were informative in 49% of the BM-positive cases. We demonstrated the utility of NGF for a more accurate diagnostic classification of early-stage MG.
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Affiliation(s)
- Oihane Pérez-Escurza
- Translational and Clinical Research Program, Cancer Research Center (IBMCC, CSIC-University of Salamanca); Cytometry Service, NUCLEUS; Department of Medicine, University of Salamanca (Universidad de Salamanca), Salamanca, Spain
- Institute of Biomedical Research of Salamanca (IBSAL), Salamanca, Spain
- Department of Medicine, University of Salamanca (Universidad de Salamanca), Salamanca, Spain
| | - Juan Flores-Montero
- Translational and Clinical Research Program, Cancer Research Center (IBMCC, CSIC-University of Salamanca); Cytometry Service, NUCLEUS; Department of Medicine, University of Salamanca (Universidad de Salamanca), Salamanca, Spain
- Institute of Biomedical Research of Salamanca (IBSAL), Salamanca, Spain
- Department of Medicine, University of Salamanca (Universidad de Salamanca), Salamanca, Spain
- Biomedical Research Networking Centre Consortium of Oncology (CIBERONC), Instituto de Salud Carlos III, Madrid, Spain
- Department of Hematology, University Hospital of Salamanca, Salamanca, Spain
| | | | - Luzalba Sanoja-Flores
- Biomedical Research Networking Centre Consortium of Oncology (CIBERONC), Instituto de Salud Carlos III, Madrid, Spain
- Institute of Biomedicine of Seville, Department of Hematology, University Hospital Virgen del Rocío of the Consejo Superior de Investigaciones Científicas (CSIC), University of Seville, Seville, Spain
| | - Julio Del Pozo
- Translational and Clinical Research Program, Cancer Research Center (IBMCC, CSIC-University of Salamanca); Cytometry Service, NUCLEUS; Department of Medicine, University of Salamanca (Universidad de Salamanca), Salamanca, Spain
| | - Quentin Lecrevisse
- Translational and Clinical Research Program, Cancer Research Center (IBMCC, CSIC-University of Salamanca); Cytometry Service, NUCLEUS; Department of Medicine, University of Salamanca (Universidad de Salamanca), Salamanca, Spain
- Institute of Biomedical Research of Salamanca (IBSAL), Salamanca, Spain
- Department of Medicine, University of Salamanca (Universidad de Salamanca), Salamanca, Spain
- Biomedical Research Networking Centre Consortium of Oncology (CIBERONC), Instituto de Salud Carlos III, Madrid, Spain
| | - Silvia Martín
- Translational and Clinical Research Program, Cancer Research Center (IBMCC, CSIC-University of Salamanca); Cytometry Service, NUCLEUS; Department of Medicine, University of Salamanca (Universidad de Salamanca), Salamanca, Spain
| | - Elín Ruth Reed
- Faculty of Medicine, University of Iceland, Reykjavík, Iceland
| | | | | | - Sigrún Þorsteinsdóttir
- Faculty of Medicine, University of Iceland, Reykjavík, Iceland
- Rigshospitalet, Copenhagen, Denmark
| | - Sæmundur Rögnvaldsson
- Faculty of Medicine, University of Iceland, Reykjavík, Iceland
- Department of Science, Landspitali University Hospital, Reykjavík, Iceland
| | - Thorvardur Jon Love
- Faculty of Medicine, University of Iceland, Reykjavík, Iceland
- Department of Science, Landspitali University Hospital, Reykjavík, Iceland
| | - Brian Durie
- Department of Hematology and Oncology, Cedars-Sinai Medical Center, Los Angeles, CA, USA
| | - Sigurður Yngvi Kristinsson
- Faculty of Medicine, University of Iceland, Reykjavík, Iceland
- Department of Science, Landspitali University Hospital, Reykjavík, Iceland
| | - Alberto Orfao
- Translational and Clinical Research Program, Cancer Research Center (IBMCC, CSIC-University of Salamanca); Cytometry Service, NUCLEUS; Department of Medicine, University of Salamanca (Universidad de Salamanca), Salamanca, Spain.
- Institute of Biomedical Research of Salamanca (IBSAL), Salamanca, Spain.
- Department of Medicine, University of Salamanca (Universidad de Salamanca), Salamanca, Spain.
- Biomedical Research Networking Centre Consortium of Oncology (CIBERONC), Instituto de Salud Carlos III, Madrid, Spain.
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Chong YP, Lim SM, Loh TP, Mollee P, Wijeratne N, Choy KW. Screening for and diagnosis of monoclonal gammopathy. J Clin Pathol 2023; 76:727-733. [PMID: 37604683 DOI: 10.1136/jcp-2023-208774] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2023] [Accepted: 08/03/2023] [Indexed: 08/23/2023]
Abstract
Monoclonal gammopathy is a spectrum of disorders characterised by clonal proliferation of plasma cells or lymphocytes, which produce abnormal immunoglobulin or its components (monoclonal proteins). Monoclonal gammopathies are often categorised as low-tumour-burden diseases (eg, amyloid light chain (AL) amyloidosis), premalignant disorders (such as monoclonal gammopathy of undetermined significance and smouldering multiple myeloma), and malignancies (eg, multiple myeloma and Waldenström's macroglobulinaemia). Such diversity of concentration and structure makes monoclonal protein a challenging clonal marker. This article provides an overview on initial laboratory testing of monoclonal gammopathy to guide clinicians and laboratory professionals in the selection and interpretation of appropriate investigations.
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Affiliation(s)
- Yuh Ping Chong
- School of Health and Biomedical Sciences, RMIT University, Bundoora, Victoria, Australia
| | - Say Min Lim
- Department of Pathology, Hospital Teluk Intan, Teluk Intan, Malaysia
| | - Tze Ping Loh
- Department of Laboratory Medicine, National University Hospital, Singapore
| | - Peter Mollee
- Pathology Queensland, Princess Alexandra Hospital, Brisbane, Queensland, Australia
- School of Medicine, The University of Queensland, Brisbane, Queensland, Australia
| | - Nilika Wijeratne
- Dorevitch Pathology, Heidelberg, Victoria, Australia
- School of Clinical Sciences at Monash Health, Department of Medicine, Nursing and Health Sciences, Monash University, Clayton, Victoria, Australia
- Eastern Health Pathology, Eastern Health, Box Hill, Victoria, Australia
| | - Kay Weng Choy
- Department of Pathology, Northern Health, Epping, Victoria, Australia
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Malek E, Wang GM, Tatsuoka C, Cullen J, Madabhushi A, Driscoll JJ. Machine Learning Approach for Rapid, Accurate Point-of-Care Prediction of M-Spike Values in Multiple Myeloma. JCO Clin Cancer Inform 2023; 7:e2300078. [PMID: 37738540 DOI: 10.1200/cci.23.00078] [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: 05/03/2023] [Revised: 07/18/2023] [Accepted: 07/20/2023] [Indexed: 09/24/2023] Open
Abstract
PURPOSE The gold standard for monitoring response status in patients with multiple myeloma (MM) is serum and urine protein electrophoresis which quantify M-spike proteins; however, the turnaround time for results is 3-7 days which delays treatment decisions. We hypothesized that machine learning (ML) could integrate readily available clinical and laboratory data to rapidly and accurately predict patient M-spike values. METHODS A retrospective chart review was performed using the deidentified, electronic medical records of 171 patients with MM. RESULTS Random forest (RF) analysis identified the weighted value of each independent variable (N = 43) integrated into the ML algorithm. Pearson and Spearman coefficients indicated that the ML-predicted M-spike values correlated highly with laboratory-measured serum protein electrophoresis values. Feature selected RF modeling revealed that only two variables-the first lagged M-spike and serum total protein-accurately predicted the M-spike. CONCLUSION Taken together, our results demonstrate the feasibility and prognostic potential of ML tools that integrate electronic data to longitudinally monitor disease burden. ML tools support the seamless, secure exchange of patient information to expedite and personalize clinical decision making and overcome geographic, financial, and social barriers that currently limit the access of underserved populations to cancer care specialists so that the benefits of medical progress are not limited to selected groups.
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Affiliation(s)
- Ehsan Malek
- Adult Hematologic Malignancies & Stem Cell Transplant Section, Seidman Cancer Center, University Hospitals Cleveland Medical Center, Cleveland, OH
- University Hospitals Cleveland Medical Center, Cleveland, OH
- Case Comprehensive Cancer Center, Case Western Reserve University, Cleveland, OH
| | - Gi-Ming Wang
- Case Comprehensive Cancer Center, Case Western Reserve University, Cleveland, OH
- Department of Population and Quantitative Health Sciences, Case Western Reserve University, School of Medicine, Cleveland, OH
| | - Curtis Tatsuoka
- Department of Population and Quantitative Health Sciences, Case Western Reserve University, School of Medicine, Cleveland, OH
- Cancer Epidemiology and Prevention, University of Pittsburgh Medical Center, Hillman Cancer Center, Pittsburgh, PA
| | - Jennifer Cullen
- Case Comprehensive Cancer Center, Case Western Reserve University, Cleveland, OH
- Department of Population and Quantitative Health Sciences, Case Western Reserve University, School of Medicine, Cleveland, OH
| | - Anant Madabhushi
- Department of Biomedical Engineering, Emory University and Georgia Institute of Technology, Atlanta, GA
- Atlanta Veterans Administration Medical Center, Atlanta, GA
| | - James J Driscoll
- Adult Hematologic Malignancies & Stem Cell Transplant Section, Seidman Cancer Center, University Hospitals Cleveland Medical Center, Cleveland, OH
- University Hospitals Cleveland Medical Center, Cleveland, OH
- Case Comprehensive Cancer Center, Case Western Reserve University, Cleveland, OH
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Monroig-Rivera CA, Cruz CNF. Unusual biclonal IgA plasma cell myeloma with aberrant expression of high-risk immunophenotypes: first report of a new diagnostic and clinical challenge. J Pathol Transl Med 2023; 57:132-137. [PMID: 36950814 PMCID: PMC10028011 DOI: 10.4132/jptm.2023.02.07] [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: 09/11/2022] [Accepted: 02/07/2023] [Indexed: 03/24/2023] Open
Abstract
IgA plasma cell myeloma (PCM) has been linked to molecular abnormalities that confer a higher risk for adverse patient outcomes. However, since IgA PCM only accounts for approximately 20% of all PCM, there are very few reports on high-risk IgA PCM. Moreover, no such reports are found on the more infrequent biclonal IgA PCM. Hence, we present a 65-year-old Puerto Rican female with acute abdominal pain, concomitant hypercalcemia, and acute renal failure. Protein electrophoresis with immunofixation found high IgA levels and detected a biclonal IgA gammopathy with kappa specificity. Histomorphologically, bone marrow showed numerous abnormal plasma cells (32%) replacing over 50% of the marrow stroma. Immunophenotyping analysis detected CD45-negative plasma cells aberrantly expressing CD33, CD43, OCT-2, and c-MYC. Chromosomal analysis revealed multiple abnormalities including the gain of chromosome 1q. Thus, we report on an unusual biclonal IgA PCM and the importance of timely diagnosing aggressive plasma cell neoplasms.
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Affiliation(s)
| | - Clara N Finch Cruz
- Department of Basic Sciences, School of Medicine - Ponce Health Sciences University, Ponce, Puerto Rico, USA
- Southern Pathology Services, Inc., Ponce, Puerto Rico, USA
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Şeneş M, Alpdemir M, Kırtıl G, Öğüş E, Çolak Samsum E, Alpdemir MF. Effects of lipemia on capillary serum protein electrophoresis in native ultra-lipemic material and intravenous lipid emulsion added sera. Clin Chem Lab Med 2022; 61:1054-1064. [PMID: 36583398 DOI: 10.1515/cclm-2022-0955] [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: 09/24/2022] [Accepted: 12/15/2022] [Indexed: 12/31/2022]
Abstract
OBJECTIVES This study aims to investigate the effect of natural ultralipemic material (NULM) and intravenous lipid emulsion (IVLE) on capillary serum protein electrophoresis (SPEP). METHODS NULM material was prepared from leftover patients' lipemic serum sample (triglyceride concentration >2,000 mg/dL) pool by a refrigerated high-speed centrifuge, and IVLE Omegaven lipid emulsion (30%) was used. Serum pools for interference study were prepared from patient samples for which serum protein electrophoresis was studied as Normal SPEP and M Peak SPEP. For both types of lipemia (DULM and IVLE), five pools with triglyceride concentrations of ∼4.52 mmol/L, ∼7.91 mmol/L, ∼14.69 mmol/L, ∼21.47 mmol/L, and ∼28.25 mmol/L were prepared. SPEP was studied in each pool with Sebia Capillarys Minicap. A repeated measure ANOVA test was used to determine the difference between the pools, and interferograms were used to evaluate the interference effect. RESULTS Interference was not detected in IVLE added Normal SPEP and M Peak SPEP pools, either % or concentrations of fractions. In NULM-added Normal SPEP and M Peak SPEP pools, significant positive interference in albumin % (p=0.002 and p<0.001 respectively) and significant negative interference in gamma% (p<0.001 and p=0.005 respectively) and M protein peak (p=0.002) fractions were detected. However, significant positive interference was seen only for albumin concentration fractions (p<0.001 for both pools). CONCLUSIONS It is vital to use NULM instead of IVLE solutions in lipemia interference studies for all laboratory tests, including CZE SPEP. The fractions concentration values calculated with the total protein concentration should be used for evaluating SPEP results.
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Affiliation(s)
- Mehmet Şeneş
- Medical Biochemistry, University of Health Sciences Ankara Training and Research Hospital, Ankara, Türkiye
| | - Medine Alpdemir
- Medical Biochemistry, University of Health Sciences Ankara Training and Research Hospital, Ankara, Türkiye
| | - Gül Kırtıl
- Medical Biochemistry, University of Health Sciences Ankara Training and Research Hospital, Ankara, Türkiye
| | - Elmas Öğüş
- Medical Biochemistry, University of Health Sciences Ankara Training and Research Hospital, Ankara, Türkiye
| | - Emel Çolak Samsum
- Medical Biochemistry, Ministry of Health Pursaklar State Hospital, Ankara, Türkiye
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Šegulja D, Matišić D, Barišić K, Rogić D. A novel approach for more precise quantification of M-protein using variables derived from immunosubtraction electropherogram and associated biochemistry analytes. Biochem Med (Zagreb) 2022; 32:030701. [PMID: 35966255 PMCID: PMC9344871 DOI: 10.11613/bm.2022.030703] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2022] [Accepted: 06/14/2022] [Indexed: 11/25/2022] Open
Abstract
Introduction Due to limitations in currently used methodologies, the widely acknowledged approach for quantifying M-protein (MP) is not available. If employed as a source of quantitative data, the immunosubtraction electropherogram (IS-EPG), a qualitative analysis of MP, has the potential to overcome known analytical issues. The aim of this study is to explore measured and derived variables obtained from immunosubtraction electropherogram as a tool for quantifying MP and to compare the derived results to currently available methods. Materials and methods Measurands were amplitudes of MP and albumin fractions. Assessed derived variables included also immunoglobulin (Ig) G, IgA, IgM and total protein data. Capillary electrophoresis was used for determination of MP (in % of total protein concentration, or concentration of MP in g/L) by perpendicular drop and tangent skimming method. Results Passing-Bablok analysis showed the most comparable results in D1Ig and D1nIg variables, and the largest discrepancies in AD1nIg and AD2nIg variables. The background presence had greater impact on D1nIg comparison results than did on D1Ig results. The contribution of albumin fraction data did not improve the comparability of the results. The coefficients of variation of derived variables were lower (maximum 3.1%) than those obtained by densitometric measurements, regardless of MP concentration, polyclonal background, or migration pattern (2.3-37.7%). Conclusion The amplitude of MP spike in IS-EPG is an valuable measurand to compute derived variables for quantifying MP. The most comparable results were achieved with the D1Ig variable. Patients with monoclonal gammopathy can benefit from increased precision employing an objective and background independent measurand, especially during longitudinal follow-up.
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Affiliation(s)
- Dragana Šegulja
- Department of Laboratory Diagnostics, University Hospital Centre Zagreb, Zagreb, Croatia
- Corresponding author:
| | | | - Karmela Barišić
- Faculty of Pharmacy and Biochemistry, University of Zagreb, Zagreb, Croatia
| | - Dunja Rogić
- Department of Laboratory Diagnostics, University Hospital Centre Zagreb, Zagreb, Croatia
- Faculty of Pharmacy and Biochemistry, University of Zagreb, Zagreb, Croatia
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Daves M, Piccin A, Vicidomini C, De Luisi A, Mega A. Utility of serum indices in a particular case of serum protein electrophoresis. Biochem Med (Zagreb) 2022; 32:030802. [PMID: 35966258 PMCID: PMC9344864 DOI: 10.11613/bm.2022.030802] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2022] [Accepted: 06/06/2022] [Indexed: 11/03/2022] Open
Abstract
Screening and measurement of monoclonal (M) proteins are commonly performed using capillary zone electrophoresis (CZE). The identification of M-protein or monoclonal component (CM) is an essential requirement for diagnosis and monitoring of monoclonal gammopathies. The detection of CM has been largely improved by CZE. Capillary electrophoresis estimates CM more accurately, because absence of variation due to different dye binding affinities of proteins as instead seen with agarose gel electrophoresis. However, interferences can be present in CZE. This occurs because all substances absorbing at 200 nm can be identified. Recognition and handling of specimens exhibiting such interferences is essential to ensure accurate diagnostic and patient safety. We herein report on an unusual case of serum protein electrophoresis, to highlight that laboratory staff must be aware of and familiarise with the information provided by laboratory instruments. For example, in the case of serum indices, about specimen quality.
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Affiliation(s)
- Massimo Daves
- Clinical Biochemical Laboratory, Hospital of Bolzano, Bolzano, Italy
- Corresponding author:
| | - Andrea Piccin
- Northern Ireland Blood Transfusion Service, Belfast, UK
- Department of Internal Medicine V, Medical University of Innsbruck, Innsbruck, Austria
- Department of Industrial Engineering, University of Trento, Trento, Italy
| | | | - Antonia De Luisi
- Clinical Biochemical Laboratory, Hospital of Bolzano, Bolzano, Italy
| | - Andrea Mega
- Division of Gastroenterology, Hospital of Bolzano, Bolzano, Italy
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Assessment of M-protein quantification using capillary electrophoresis and immunosubtraction-based integration in clinical samples with low M-protein concentrations. Clin Biochem 2022; 107:7-12. [DOI: 10.1016/j.clinbiochem.2022.05.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2022] [Revised: 05/23/2022] [Accepted: 05/30/2022] [Indexed: 11/22/2022]
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11
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Keren DF, Bocsi G, Billman BL, Etzell J, Faix JD, Kumar S, Lipe B, McCudden C, Montgomery R, Murray DL, Rai AJ, Redondo TC, Souter L, Ventura CB, Ansari MQ. Laboratory Detection and Initial Diagnosis of Monoclonal Gammopathies. Arch Pathol Lab Med 2022; 146:575-590. [PMID: 34347866 DOI: 10.5858/arpa.2020-0794-cp] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/30/2021] [Indexed: 11/06/2022]
Abstract
CONTEXT.— The process for identifying patients with monoclonal gammopathies is complex. Initial detection of a monoclonal immunoglobulin protein (M protein) in the serum or urine often requires compilation of analytical data from several areas of the laboratory. The detection of M proteins depends on adequacy of the sample provided, available clinical information, and the laboratory tests used. OBJECTIVE.— To develop an evidence-based guideline for the initial laboratory detection of M proteins. DESIGN.— To develop evidence-based recommendations, the College of American Pathologists convened a panel of experts in the diagnosis and treatment of monoclonal gammopathies and the laboratory procedures used for the initial detection of M proteins. The panel conducted a systematic literature review to address key questions. Using the Grading of Recommendations Assessment, Development, and Evaluation approach, recommendations were created based on the available evidence, strength of that evidence, and key judgements as defined in the Grading of Recommendations Assessment, Development, and Evaluation Evidence to Decision framework. RESULTS.— Nine guideline statements were established to optimize sample selection and testing for the initial detection and quantitative measurement of M proteins used to diagnose monoclonal gammopathies. CONCLUSIONS.— This guideline was constructed to harmonize and strengthen the initial detection of an M protein in patients displaying symptoms or laboratory features of a monoclonal gammopathy. It endorses more comprehensive initial testing when there is suspicion of amyloid light chain amyloidosis or neuropathies, such as POEMS (polyneuropathy, organomegaly, endocrinopathy, M protein, and skin changes) syndrome, associated with an M protein.
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Affiliation(s)
- David F Keren
- From the Department of Pathology, Michigan Medicine, University of Michigan, Ann Arbor (Keren).,Keren and Ansari served as guideline cochairs
| | - Gregary Bocsi
- The Department of Pathology, University of Colorado Anschutz, Aurora (Bocsi)
| | - Brooke L Billman
- Governance Services (Billman), College of American Pathologists, Northfield, Illinois
| | - Joan Etzell
- The Department of Pathology, Sutter Health Shared Laboratory, Livermore, California (Etzell)
| | - James D Faix
- tHe Department of Pathology, Montefiore Medical Center, Bronx, New York (Faix)
| | - Shaji Kumar
- The Department of Internal Medicine, Mayo Clinic, Rochester, Minnesota (Kumar)
| | - Brea Lipe
- The Department of Medicine, University of Rochester Medical Center, Rochester, New York (Lipe)
| | - Christopher McCudden
- The Department of Pathology and Laboratory Medicine, The Ottawa Hospital, Ottawa, Ontario, Canada (McCudden)
| | | | - David L Murray
- The Department of Pathology, PeaceHealth Southwest Medical Center, Vancouver, Washington (Murray)
| | - Alex J Rai
- The Department of Pathology and Cell Biology, Columbia University Medical Center, New York, New York (Rai)
| | | | - Lesley Souter
- Methodology Consultant, Hamilton, Ontario, Canada (Souter)
| | | | - Mohammad Qasim Ansari
- and the Department of Pathology and Laboratory Medicine, Louis Stokes Veterans Affairs Medical Center, Cleveland, Ohio (Ansari).,Keren and Ansari served as guideline cochairs
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12
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Prisi S, Khurana V, Saijpaul R, Verma R, Chandra L, Koner BC. Unraveling the Possibilities of Monoclonal Protein Migration, Identification, and Characterization in SPEP on Capillary Zone Electrophoresis. J Lab Physicians 2022; 14:505-510. [DOI: 10.1055/s-0042-1744242] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022] Open
Abstract
AbstractSerum protein electrophoresis (SPEP) is a method by which proteins present in serum are separated into different fractions based on their molecular weight and electric charge. Presence of M spike, composed of monoclonal protein, on electrophoretogram is a characteristic finding that can be seen in monoclonal gammopathies like multiple myeloma. M spike is most commonly seen in the gamma region however, the M-spike can be observed in fraction other than the Y fraction as well i.e. in the beta region and rarely alpha region. Here we have enumerated few cases where M protein has been seen in fractions other than the gamma region. Thus one needs to be cautious about the variable appearance of M-spike during interpretation of SPEP as some physiological proteins if elevated can also give rise to similar spike sometimes referred as pseudo monoclonal pattern.
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Affiliation(s)
- Shailata Prisi
- Department of Biochemistry, Maulana Azad Medical College, New Delhi, India
| | - Vatsala Khurana
- Department of Biochemistry, Maulana Azad Medical College, New Delhi, India
| | - Rajni Saijpaul
- Department of Biochemistry, Maulana Azad Medical College, New Delhi, India
| | - Rashmi Verma
- Department of Biochemistry, Maulana Azad Medical College, New Delhi, India
| | - Lal Chandra
- Department of Biochemistry, Maulana Azad Medical College, New Delhi, India
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13
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Kitson AL, Taylor AS, Giacherio DA, Keren DF. Reflexing Suspicious β-Region Findings on Capillary Serum Protein Electrophoresis to Immunofixation or Immunosubtraction for Detecting Monoclonal Proteins. Am J Clin Pathol 2022; 157:171-179. [PMID: 34519791 DOI: 10.1093/ajcp/aqab108] [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: 03/05/2021] [Accepted: 05/23/2021] [Indexed: 11/12/2022] Open
Abstract
OBJECTIVES Monoclonal immunoglobulins (M-proteins) that migrate in the β region on serum protein electrophoresis (SPEP) are often cloaked by this region's normal constituents. The present study interrogates the utility of using both quantitative and qualitative alterations in β-region bands for detection of β-migrating M-proteins. METHODS Consecutive SPEP cases analyzed by capillary electrophoresis were searched to identify the initial workup on 1,841 patients with increased total β regions, suspicious β-region findings resulting in reflex immunofixation (IFE), or immunosubtraction (ISUB). To augment quantitative information, separate β1 and β2 measurements were established and retrospectively used to evaluate their sensitivity for M-protein detection. RESULTS We identified M-proteins in 205 (11.1%) cases, including immunoglobulin A (IgA) (54%), IgG (24%), IgM (13%), and free light chain (9%) isotypes. Of the 15 cases flagged by separate β1 and β2 measurements that were not identified by total β-region measurement, 1 progressed to myeloma. Of the 56 β-migrating M-proteins identified by qualitative features but without increase in any of the β-region measurements, 1 progressed to myeloma. CONCLUSIONS A combination of separate measurements for β1 and β2 regions together with detection of β-region distortions increase sensitivity for identifying β-migrating M-proteins via reflex IFE or ISUB.
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Affiliation(s)
- Amanda L Kitson
- Department of Pathology, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Alexander S Taylor
- Department of Pathology, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Donald A Giacherio
- Department of Pathology, University of Michigan Medical School, Ann Arbor, MI, USA
| | - David F Keren
- Department of Pathology, University of Michigan Medical School, Ann Arbor, MI, USA
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14
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To skim or splice? Comparing the quantification of M-proteins using two peak-integration protocols across multiple electrophoresis platforms. Clin Biochem 2022; 102:44-49. [PMID: 35093313 DOI: 10.1016/j.clinbiochem.2022.01.007] [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: 10/26/2021] [Revised: 12/22/2021] [Accepted: 01/24/2022] [Indexed: 11/23/2022]
Abstract
OBJECTIVES M-protein quantification by peak integration in serum protein electrophoresis (SPE) plays a central role in diagnosing, prognosing and monitoring monoclonal gammopathies. The conventional perpendicular drop (PD) integration approach integrates M-spikes from the baseline, which performs acceptably when the M-protein concentration is relatively high compared to the amount of background proteins present. The alternative peak-integration protocol by tangential skim (TS), however, allows for more accurate M-protein estimations by excluding background proteins. Despite some guideline recommendations, TS has been poorly adopted, making an understanding of the differences between the two protocols and their potential impacts paramount when considering a change from PD to TS. DESIGN & METHODS We conducted retrospective investigations of the differences in M-protein quantification over large concentration ranges between PD and TS on 3 of the most popular electrophoresis platforms. RESULTS Compared to PD, TS gave consistently lower results; the differences between the two methods increased tremendously and became more sporadic as M-protein concentrations dropped below 15 g/L in all 3 platforms. At < 15 g/L, the average % difference ranged from -81 % to -95 %, while above 15 g/L, the average % difference was only -13 to -31 %. Medical decision point analyses using linear regression predicted statistically significant and platform-dependent differences, which could impact clinical interpretation. CONCLUSIONS Careful consideration of the magnitude of concentration changes and the potential impacts on patient classification and management should be made when switching to TS for M-protein quantification.
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15
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Rekhtina IG, Mendeleeva LP, Soboleva NP, Dubina IA, Pervakova MI, Lapin SV. Detection of paraprotein in plasma cell tumors. TERAPEVT ARKH 2022. [DOI: 10.26442/10.26442/00403660.2022.01.201326] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Paraprotein is a laboratory biomarker of plasma cell tumors and other lymphoproliferative diseases. Its determination is necessary for diagnosing, monitoring and assessment of therapy effectiveness. The lecture presents the main methods of qualitative and quantative analysis of monoclonal proteins: gel electrophoresis, capillary electrophoresis, immunofixation and nephelometry features, possibilities and limitations are reviewed. The main sources of errors and artifacts during these studies are considered. Also the difficulties in the diagnosis and interpretation of the results of serum and urine tests are highlighted.
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16
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Mrosewski I, Urbank M. Identification of Paraproteins via Serum Immunofixation or Serum Immunosubtraction and Immunoturbidimetric Quantitation of Serum Immunoglobulins in the Laboratory Testing for Monoclonal Gammopathies. Arch Pathol Lab Med 2021; 145:1552-1557. [DOI: 10.5858/arpa.2020-0441-oa] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/11/2020] [Indexed: 11/06/2022]
Abstract
Context.—
In laboratory testing for monoclonal gammopathies, paraproteins are identified via serum immunofixation or serum immunosubtraction, and immunoturbidimetric quantitation of serum immunoglobulins is often used.
Objective.—
To evaluate methodologic differences between serum immunofixation and serum immunosubtraction, as well as in the quantitation of serum immunoglobulins on different clinical chemical platforms.
Design.—
Three hundred twenty-two unique routine patient samples were blinded and used for comparison between serum immunofixation on Sebia's HYDRASIS 2 and serum immunosubtraction on Sebia's CAPILLARYS 2, as well as between quantitation results of immunoglobulin A, G, and M on Abbott's ARCHITECT c16000PLUS and Roche's Cobas c 502 module. Microsoft Excel 2019 with the add-on Abacus 2.0 and MedCalc were used for statistical analysis and graphic depiction via bubble diagram, Passing-Bablok regressions, and Bland-Altman plots.
Results.—
The median age of patients was 75 years, and samples with paraproteinemia were nearly evenly split between sexes. Paraprotein identification differed remarkably between immunofixation and immunosubtraction. Quantitation of serum immunoglobulins showed higher values on Abbott's ARCHITECT c16000PLUS when compared with Roche's Cobas c 502 module.
Conclusions.—
Identification of paraproteins via serum immunosubtraction is inferior to serum immunofixation, which can have implications on the diagnosis and monitoring of patients with monoclonal gammopathy. If immunoturbidimetric quantitation of immunoglobulins is used for follow-up, the same clinical-chemical platform should be used consistently.
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Affiliation(s)
- Ingo Mrosewski
- From the Department of Laboratory Medicine, MDI Limbach Berlin GmbH, Berlin, Germany
| | - Matthias Urbank
- From the Department of Laboratory Medicine, MDI Limbach Berlin GmbH, Berlin, Germany
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17
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Muccio S, Tavernier A, Rouchon MC, Roccon A, Dai S, Finn G, Macé S, Boutet V, Fedeli O. Validated Method Based on Immunocapture and Liquid Chromatography Coupled to High-Resolution Mass Spectrometry to Eliminate Isatuximab Interference with M-Protein Measurement in Serum. Anal Chem 2021; 93:15236-15242. [PMID: 34762405 DOI: 10.1021/acs.analchem.1c03410] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
In multiple myeloma (MM) disease, malignant plasma cells produce excessive quantities of a monoclonal immunoglobulin (Ig), known as M-protein. M-protein levels are measured in the serum of patients with MM using electrophoresis techniques to determine the response to treatment. However, therapeutic monoclonal antibodies, such as isatuximab, may confound signals using electrophoresis assays. We developed a robust assay based on immunocapture and liquid chromatography coupled to high-resolution mass spectrometry (IC-HPLC-HRMS) in order to eliminate this interference. Following immunocapture of Ig and free light chains (LC) in serum, heavy chains (HC) and LC were dissociated using dithiothreitol, sorted by liquid chromatography and analyzed using HRMS (Q-Orbitrap). This method allowed the M-proteins to be characterized and the signals from isatuximab and M-proteins to be discriminated. As M-protein is specific to each patient, no standards were available for absolute quantification. We therefore used alemtuzumab (an IgG kappa mAb) as a surrogate analyte for the semiquantification of M-protein in serum. This assay was successfully validated in terms of selectivity/specificity, accuracy/precision, robustness, dilution linearity, and matrix variability from 10.0 to 200 μg/mL in human serum. This method was used for clinical assessment of samples and eliminated potential interference due to isatuximab when monitoring patients with MM.
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Affiliation(s)
- Stéphane Muccio
- Sanofi R&D, 371 Rue du Professeur Blayac, 34184 Montpellier, France
| | | | | | - Alain Roccon
- Sanofi R&D, 371 Rue du Professeur Blayac, 34184 Montpellier, France
| | - Shujia Dai
- Sanofi Translational Sciences, 640 Memorial Drive, Cambridge, Massachusetts 02139, United States
| | - Greg Finn
- Sanofi Oncology, 640 Memorial Drive, Cambridge, Massachusetts 02139, United States
| | - Sandrine Macé
- Sanofi R&D, 1 Avenue Pierre Brossolette, 91385 Chilly-Mazarin, France
| | - Valérie Boutet
- Sanofi R&D, 1 Avenue Pierre Brossolette, 91385 Chilly-Mazarin, France
| | - Olivier Fedeli
- Sanofi R&D, 371 Rue du Professeur Blayac, 34184 Montpellier, France
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18
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Wilhite D, Arfa A, Cotter T, Savage NM, Bollag RJ, Singh G. Multiple myeloma: Detection of free monoclonal light chains by modified immunofixation electrophoresis with antisera against free light chains. Pract Lab Med 2021; 27:e00256. [PMID: 34703870 PMCID: PMC8521168 DOI: 10.1016/j.plabm.2021.e00256] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2021] [Revised: 09/13/2021] [Accepted: 10/05/2021] [Indexed: 01/01/2023] Open
Abstract
Introduction Neoplastic monoclonal gammopathies are frequently associated with production of excess free monoclonal light chains. A sensitive method for detecting free monoclonal light chains in serum could provide a marker for residual/minimal residual disease and as an adjunct to serum protein electrophoresis to serve as a screening method for monoclonal gammopathies. Methods Conventional serum immunofixation electrophoresis was modified by applying undiluted serum samples, and staining for serum free light chains with antisera specific to free light chains. Washing/blotting of gels was enhanced to remove residual proteins that did not bind to the antibodies including intact monoclonal immunoglobulins. Results from this modified immunofixation electrophoresis were compared with results from commercially available MASS-FIX/MALDI assay. Results Monoclonal free kappa light chains could be detected to a concentration of about 1.78 mg/L and monoclonal free lambda light chains to a concentration of about 1.15 mg/L without the need for special equipment. Comparison of these thresholds with parallel results from a commercially available MASS-FIX/MALDI assay revealed the modified electrophoretic method to be more sensitive in the context of free monoclonal light chains. Conclusions Modified serum immunofixation electrophoresis has been shown to detect low levels of monoclonal free light chains at a sensitivity suitable for the method to be used in detecting minimal residual disease, and potentially in a screening assay for monoclonal gammopathies. The disparity in the results with commercially available MASS-FIX/MALDI assay is postulated to be due to limited repertoire of reactivity of nanobodies of camelid origin.
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Affiliation(s)
- Dorian Wilhite
- Department of Pathology, Medical College of Georgia at Augusta University, 1120 15th Street, BI 2008A, Augusta, GA, 30912, USA
| | - Ahmed Arfa
- Department of Pathology, Medical College of Georgia at Augusta University, 1120 15th Street, BI 2008A, Augusta, GA, 30912, USA
| | - Thomas Cotter
- Department of Pathology, Medical College of Georgia at Augusta University, 1120 15th Street, BI 2008A, Augusta, GA, 30912, USA
| | - Natasha M Savage
- Department of Pathology, Medical College of Georgia at Augusta University, 1120 15th Street, BI 2008A, Augusta, GA, 30912, USA
| | - Roni J Bollag
- Department of Pathology, Medical College of Georgia at Augusta University, 1120 15th Street, BI 2008A, Augusta, GA, 30912, USA
| | - Gurmukh Singh
- Department of Pathology, Medical College of Georgia at Augusta University, 1120 15th Street, BI 2008A, Augusta, GA, 30912, USA
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19
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Liyasova M, McDonald Z, Taylor P, Gorospe K, Xu X, Yao C, Liu Q, Yang L, Atenafu EG, Piza G, Ma B, Reece D, Trudel S. A Personalized Mass Spectrometry-Based Assay to Monitor M-Protein in Patients with Multiple Myeloma (EasyM). Clin Cancer Res 2021; 27:5028-5037. [PMID: 34210683 PMCID: PMC9401514 DOI: 10.1158/1078-0432.ccr-21-0649] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2021] [Revised: 04/27/2021] [Accepted: 06/24/2021] [Indexed: 01/07/2023]
Abstract
PURPOSE M-protein is a well-established biomarker used for multiple myeloma monitoring. Current improvements in multiple myeloma treatment created the need to monitor minimal residual disease (MRD) with high sensitivity. Measuring residual levels of M-protein in serum by MS was established as a sensitive assay for disease monitoring. In this study we evaluated the performance of EasyM-a noninvasive, sensitive, MS-based assay for M-protein monitoring. EXPERIMENTAL DESIGN Twenty-six patients enrolled in MCRN-001 clinical trial of two high-dose alkylating agents as conditioning followed by lenalidomide maintenance were selected for the study. All selected patients achieved complete responses (CR) during treatment, whereas five experienced progressive disease on study. The M-protein of each patient was first sequenced from the diagnostic serum using our de novo protein sequencing platform. The patient-specific M-protein peptides were then measured by targeted MS assay to monitor the response to treatment. RESULTS The M-protein doubling over 6 months measured by EasyM could predict the relapse in 4 of 5 relapsed patients 2 to 11 months earlier than conventional testing. In 21 disease-free patients, the M-protein was still detectable by EasyM despite normal FLC and MRD negativity. Importantly, of 72 MRD negative samples with CR status, 62 were positive by EasyM. The best sensitivity achieved by EasyM, detecting 0.58 mg/L of M-protein, was 1,000- and 200-fold higher compared with serum protein electrophoresis and immunofixation electrophoresis, respectively. CONCLUSIONS EasyM was demonstrated to be a noninvasive, sensitive assay with superior performance compared with other assays, making it ideal for multiple myeloma monitoring and relapse prediction.
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Affiliation(s)
| | | | - Paul Taylor
- Rapid Novor, Inc., Kitchener, Ontario, Canada
| | | | - Xin Xu
- Rapid Novor, Inc., Kitchener, Ontario, Canada
| | - Chenyu Yao
- Rapid Novor, Inc., Kitchener, Ontario, Canada
| | - Qixin Liu
- Rapid Novor, Inc., Kitchener, Ontario, Canada
| | | | | | - Giovanni Piza
- Princess Margaret Cancer Centre, Toronto, Ontario, Canada
| | - Bin Ma
- University of Waterloo, Waterloo, Ontario, Canada
| | - Donna Reece
- Princess Margaret Cancer Centre, Toronto, Ontario, Canada
| | - Suzanne Trudel
- Princess Margaret Cancer Centre, Toronto, Ontario, Canada.,Corresponding Author: Suzanne Trudel, Princess Margaret Cancer Centre, University Health Network, 610 University Avenue, Toronto, ON, Canada M5G 2M9. E-mail:
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20
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Salvagno GL, Danese E, Lippi G. Mass spectrometry and total laboratory automation: opportunities and drawbacks. Clin Chem Lab Med 2021; 58:994-1001. [PMID: 32191622 DOI: 10.1515/cclm-2019-0723] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2019] [Accepted: 02/14/2020] [Indexed: 11/15/2022]
Abstract
The diffusion of laboratory automation, initiated nearly 50 years ago with consolidation of preanalytical, clinical chemistry and immunochemistry workstations, is now also gradually embracing mass spectrometry (MS). As for other diagnostic disciplines, the automation of MS carries many advantages, such as efficient personnel management (i.e. improving working atmosphere by decreasing manual activities, lowering health risks, simplifying staff training), better organization (i.e. reducing workloads, improving inventory handling, increasing analytical process standardization) and the possibility to reduce the number of platforms. The development and integration of different technologies into automated MS analyzers will also generate technical and practical advantages, such as prepackaged and ready-to-use reagents, automated dispensing, incubation and measurement, automated sample processing (e.g. system fit for many models of laboratory automation, bar code readers), multiplex testing, automatic data processing, also including quality control assessment, and automated validation/interpretation (e.g. autoverification). A new generation of preanalytical workstations, which can be directly connected to MS systems, will allow the automation of manual extraction and elimination of time-consuming activities, such as tube labeling and capping/decapping. The use of automated liquid-handling platform for pipetting samples, along with addition of internal standards, may then enable the optimization of some steps of extraction and protein precipitation, thus decreasing turnaround time and increasing throughput in MS testing. Therefore, this focused review is aimed at providing a brief update on the importance of consolidation and integration of MS platforms in laboratory automation.
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Affiliation(s)
| | - Elisa Danese
- Section of Clinical Biochemistry, University of Verona, Verona, Italy
| | - Giuseppe Lippi
- Section of Clinical Biochemistry, University of Verona, Verona, Italy
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21
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Omar N, Madwani K, Moideen P, Manthei DM, Keren DF, Singh G. Accurate Quantification of Monoclonal Immunoglobulins Migrating in the Beta Region on Protein Electrophoresis. Lab Med 2021; 53:138-144. [PMID: 34388246 DOI: 10.1093/labmed/lmab055] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
BACKGROUND The concentration of monoclonal immunoglobulins (Igs) in neoplastic monoclonal gammopathic manifestations is generally measured by densitometric scanning of the monoclonal peaks on gel or by measuring absorbance at 210 nm in capillary electrophoresis (CE). For monoclonal Igs migrating in the beta region, measurement is complicated by the major beta-region proteins, namely, transferrin and C3. METHODS C3 interference in densitometry was eliminated by heat treatment of serum, and monoclonal Igs were quantified by densitometry of the residual band. The immunochemical measurement of transferrin was converted to its equivalent densitometric quantity. For monoclonal Ig migrating with transferrin, the contribution of the latter was removed by subtracting the converted transferrin concentration from the combined densitometric quantification of the band. With CE, monoclonal Ig was measured by using immunosubtraction (ISUB) to guide demarcation. RESULTS The results obtained using the C3 depletion and transferrin subtraction method were lower and yet comparable to the results derived from using CE measurement guided by ISUB. As we expected, the results from both methods were lower than those derived from a perpendicular drop measurement of the peak or via nephelometric assay of the involved isotype. DISCUSSION Accurate measurement of monoclonal Igs is important for the diagnosis and monitoring of monoclonal gammopathic manifestations. Determination of serum free light chain concentration per gram of monoclonal Ig is an essential measure for the diagnosis of light chain-predominant multiple myeloma. The method described herein improves accuracy of measurements for monoclonal Igs migrating in the beta region, without the need for special reagents or equipment.
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Affiliation(s)
- Nivin Omar
- Department of Pathology, Medical College of Georgia at Augusta University, Augusta, Georgia
| | - Kiran Madwani
- Department of Pathology, Medical College of Georgia at Augusta University, Augusta, Georgia
| | - Pramila Moideen
- Department of Pathology, Medical College of Georgia at Augusta University, Augusta, Georgia
| | | | | | - Gurmukh Singh
- Department of Pathology, Medical College of Georgia at Augusta University, Augusta, Georgia
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22
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Turner KA, Frinack JL, Ettore MW, Tate JR, Graziani MS, Jacobs JFM, Booth RA, McCudden CR, Keren DF, Delgado JC, Zemtsovskaja G, Fullinfaw RO, Caldini A, de Malmanche T, Katakouzinos K, Burke M, Palladini G, Altinier S, Zaninotto M, Righetti G, Melki MT, Bell S, Willrich MAV. An international multi-center serum protein electrophoresis accuracy and M-protein isotyping study. Part I: factors impacting limit of quantitation of serum protein electrophoresis. Clin Chem Lab Med 2021; 58:533-546. [PMID: 31940284 DOI: 10.1515/cclm-2019-1104] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2019] [Accepted: 12/02/2019] [Indexed: 11/15/2022]
Abstract
Background Serum protein electrophoresis (SPEP) is used to quantify the serum monoclonal component or M-protein, for diagnosis and monitoring of monoclonal gammopathies. Significant imprecision and inaccuracy pose challenges in reporting small M-proteins. Using therapeutic monoclonal antibody-spiked sera and a pooled beta-migrating M-protein, we aimed to assess SPEP limitations and variability across 16 laboratories in three continents. Methods Sera with normal, hypo- or hypergammaglobulinemia were spiked with daratumumab, Dara (cathodal migrating), or elotuzumab, Elo (central-gamma migrating), with concentrations from 0.125 to 10 g/L (n = 62) along with a beta-migrating sample (n = 9). Provided with total protein (reverse biuret, Siemens), laboratories blindly analyzed samples according to their SPEP and immunofixation (IFE) or immunosubtraction (ISUB) standard operating procedures. Sixteen laboratories reported the perpendicular drop (PD) method of gating the M-protein, while 10 used tangent skimming (TS). A mean percent recovery range of 80%-120% was set as acceptable. The inter-laboratory %CV was calculated. Results Gamma globulin background, migration pattern and concentration all affect the precision and accuracy of quantifying M-proteins by SPEP. As the background increases, imprecision increases and accuracy decreases leading to overestimation of M-protein quantitation especially evident in hypergamma samples, and more prominent with PD. Cathodal migrating M-proteins were associated with less imprecision and higher accuracy compared to central-gamma migrating M-proteins, which is attributed to the increased gamma background contribution in M-proteins migrating in the middle of the gamma fraction. There is greater imprecision and loss of accuracy at lower M-protein concentrations. Conclusions This study suggests that quantifying exceedingly low concentrations of M-proteins, although possible, may not yield adequate accuracy and precision between laboratories.
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Affiliation(s)
- Katherine A Turner
- Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN, USA
| | - Jody L Frinack
- Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN, USA
| | - Michael W Ettore
- Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN, USA
| | - Jillian R Tate
- Department of Chemical Pathology, Pathology Queensland, Royal Brisbane and Women's Hospital, Brisbane, QLD, Australia
| | | | - Joannes F M Jacobs
- Department of Laboratory Medicine, Radboud University Medical Center, Laboratory Medical Immunology, Nijmegen, the Netherlands
| | - Ronald A Booth
- Department of Pathology and Laboratory Medicine, The Ottawa Hospital, Ottawa, ON, Canada
| | - Christopher R McCudden
- Department of Pathology and Laboratory Medicine, The Ottawa Hospital, Ottawa, ON, Canada
| | | | - Julio C Delgado
- ARUP Laboratories, Department of Pathology, University of Utah School of Medicine, Salt Lake City, UT, USA
| | - Galina Zemtsovskaja
- Clinical Chemistry Laboratory, North Estonia Medical Centre, Tallinn, Estonia
| | - Robert O Fullinfaw
- Department of Chemical Pathology, The Royal Melbourne Hospital, Melbourne, Victoria, Australia
| | - Anna Caldini
- General Laboratory, Careggi University Hospital, Florence, Italy
| | - Theo de Malmanche
- NSW Health Pathology, Immunology Department, John Hunter Hospital, New Lambton Heights, NSW, Australia
| | - Katina Katakouzinos
- Immunopathology Department, Royal Prince Alfred Hospital, Missenden Rd, Camperdown, NSW, Australia
| | - Matthew Burke
- Department of Chemical Pathology, Pathology Queensland, Royal Brisbane and Women's Hospital, Brisbane, QLD, Australia
| | - Giovanni Palladini
- Amyloidosis Research and Treatment Center, Foundation IRCCS Policlinico San Matteo, and Department of Molecular Medicine, University of Pavia, Pavia, Italy
| | - Sara Altinier
- Laboratory Medicine of the University Hospital of Padova, Padova, Italy
| | - Martina Zaninotto
- Laboratory Medicine of the University Hospital of Padova, Padova, Italy
| | | | | | | | - Maria Alice Vieira Willrich
- Division of Clinical Biochemistry and Immunology, Department of Laboratory Medicine and Pathology, Mayo Clinic, 200 First Street SW, Rochester, MN 55905, USA
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23
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Jacobs JFM, Turner KA, Graziani MS, Frinack JL, Ettore MW, Tate JR, Booth RA, McCudden CR, Keren DF, Delgado JC, Zemtsovskaja G, Fullinfaw RO, Caldini A, de Malmanche T, Katakouzinos K, Burke M, Palladini G, Altinier S, Zaninotto M, Righetti G, Melki MT, Bell S, Willrich MAV. An international multi-center serum protein electrophoresis accuracy and M-protein isotyping study. Part II: limit of detection and follow-up of patients with small M-proteins. Clin Chem Lab Med 2021; 58:547-559. [PMID: 31940285 DOI: 10.1515/cclm-2019-1105] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2019] [Accepted: 12/17/2019] [Indexed: 11/15/2022]
Abstract
Background Electrophoretic methods to detect, characterize and quantify M-proteins play an important role in the management of patients with monoclonal gammopathies (MGs). Significant uncertainty in the quantification and limit of detection (LOD) is documented when M-proteins are <10 g/L. Using spiked sera, we aimed to assess the variability in intact M-protein quantification and LOD across 16 laboratories. Methods Sera with normal, hypo- or hyper-gammaglobulinemia were spiked with daratumumab or elotuzumab, with concentrations from 0.125 to 10 g/L (n = 62) along with a beta-migrating sample (n = 9). Laboratories blindly analyzed samples according to their serum protein electrophoresis (SPEP)/isotyping standard operating procedures. LOD and intra-laboratory percent coefficient of variation (%CV) were calculated and further specified with regard to the method (gel/capillary electrophoresis [CZE]), gating strategy (perpendicular drop [PD]/tangent skimming [TS]), isotyping (immunofixation/immunosubtraction [ISUB]) and manufacturer (Helena/Sebia). Results All M-proteins ≥1 g/L were detected by SPEP. With isotyping the LOD was moderately more sensitive than with SPEP. The intensity of polyclonal background had the biggest negative impact on LOD. Independent of the method used, the intra-laboratory imprecision of M-protein quantification was small (mean CV = 5.0%). Low M-protein concentration and high polyclonal background had the strongest negative impact on intra-laboratory precision. All laboratories were able to follow trend of M-protein concentrations down to 1 g/L. Conclusions In this study, we describe a large variation in the reported LOD for both SPEP and isotyping; overall LOD is most affected by the polyclonal immunoglobulin background. Satisfactory intra-laboratory precision was demonstrated. This indicates that the quantification of small M-proteins to monitor patients over time is appropriate, when subsequent testing is performed within the same laboratory.
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Affiliation(s)
- Joannes F M Jacobs
- Laboratory Medical Immunology, Department of Laboratory Medicine, Radboud University Medical Center, Geert Grooteplein 10, 6525 GA Nijmegen, The Netherlands
| | - Katherine A Turner
- Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN, USA
| | | | - Jody L Frinack
- Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN, USA
| | - Michael W Ettore
- Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN, USA
| | - Jillian R Tate
- Department of Chemical Pathology, Pathology Queensland, Royal Brisbane and Women's Hospital, Brisbane, QLD, Australia
| | - Ronald A Booth
- Department of Pathology and Laboratory Medicine, The Ottawa Hospital, Ottawa, ON, Canada
| | - Christopher R McCudden
- Department of Pathology and Laboratory Medicine, The Ottawa Hospital, Ottawa, ON, Canada
| | - David F Keren
- Department of Pathology, The University of Michigan, Ann Arbor, MI, USA
| | - Julio C Delgado
- ARUP Laboratories, Department of Pathology, University of Utah School of Medicine, Salt Lake City, UT, USA
| | - Galina Zemtsovskaja
- Clinical Chemistry Laboratory, North Estonia Medical Centre, Tallinn, Estonia
| | - Robert O Fullinfaw
- Department of Chemical Pathology, The Royal Melbourne Hospital, Melbourne, Victoria, Australia
| | - Anna Caldini
- General Laboratory, Careggi University Hospital, Florence, Italy
| | - Theo de Malmanche
- NSW Health Pathology, Immunology Department, John Hunter Hospital, New Lambton Heights NSW, Australia
| | - Katina Katakouzinos
- Immunopathology Department, Royal Prince Alfred Hospital, Camperdown, NSW, Australia
| | - Matthew Burke
- Department of Chemical Pathology, Pathology Queensland, Royal Brisbane and Women's Hospital, Brisbane, QLD, Australia
| | - Giovanni Palladini
- Amyloidosis Research and Treatment Center, Foundation IRCCS Policlinico San Matteo, and Department of Molecular Medicine, University of Pavia, Pavia, Italy
| | - Sara Altinier
- Laboratory Medicine of the University Hospital of Padova, Padova, Italy
| | - Martina Zaninotto
- Laboratory Medicine of the University Hospital of Padova, Padova, Italy
| | | | | | | | - Maria Alice Vieira Willrich
- Division of Clinical Biochemistry and Immunology, Department of Laboratory Medicine and Pathology, Mayo Clinic, 200 First Street SW, Rochester, MN 55905, USA
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Lv LY, Shi DB, Jia ZW. Do not measure an extra high value monoclonal IgM by immunoturbidity: a case report. Clin Chem Lab Med 2021; 59:e149-e152. [PMID: 33068378 DOI: 10.1515/cclm-2020-0973] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2020] [Accepted: 10/08/2020] [Indexed: 11/15/2022]
Affiliation(s)
- Li-Ying Lv
- Department of Clinical Laboratory, The First Affiliated Hospital of Anhui Medical University, Hefei, Anhui, P.R. China
| | - De-Bao Shi
- Department of Clinical Laboratory, The First Affiliated Hospital of Anhui Medical University, Hefei, Anhui, P.R. China
| | - Zhong-Wei Jia
- Department of Clinical Laboratory, The First Affiliated Hospital of Anhui Medical University, Hefei, Anhui, P.R. China
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25
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Visram A, Vaxman I, S Al Saleh A, Parmar H, Dispenzieri A, Kapoor P, Lacy MQ, Gertz MA, Buadi FK, Hayman SR, Dingli D, Warsame R, Kourelis T, Siddiqui M, Gonsalves W, Muchtar E, Lust JA, Leung N, Kyle RA, Murray D, Rajkumar SV, Kumar S. Disease monitoring with quantitative serum IgA levels provides a more reliable response assessment in multiple myeloma patients. Leukemia 2021; 35:1428-1437. [PMID: 33623138 PMCID: PMC8102180 DOI: 10.1038/s41375-021-01180-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2020] [Revised: 01/13/2021] [Accepted: 02/01/2021] [Indexed: 01/22/2023]
Abstract
Unlike IgG monoclonal proteins (MCPs), IgA MCP quantification is unreliable due to beta-migration of IgA MCPs on serum protein electrophoresis (SPEP). The utility of nephelometric quantitative IgA (qIgA) to monitor IgA multiple myeloma (MM) is unclear. We retrospectively studied disease response kinetics using qIgA versus MCPs by SPEP, and developed and validated novel qIgA disease assessment criteria in 491 IgA MM patients. The SPEP MCP nadir occurred a median of 41 (IQR 0-102) days before the qIgA. The median time to achieve a partial response (PR) was shorter using standard IMWG versus qIgA response criteria (32 vs 58 days, p < 0.001). Stratification by qIgA criteria, unlike IMWG criteria, led to clear separation of the progression-free survival curves of patients achieving a PR or very good PR. There was a consistent trend toward earlier detection of disease progression using qIgA versus IMWG progression criteria. In conclusion, monitoring IgA MM using MCP-based IMWG criteria may be falsely reassuring, given that MCP levels on SPEP decrease faster than qIgA levels. The qIgA response criteria more accurately stratify patients based on the progression risk and may detect disease progression earlier, which may lead to more consistent measurement of trial endpoints and improved patient outcomes.
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Affiliation(s)
- Alissa Visram
- Division of Hematology, Mayo Clinic, Rochester, MN, USA.,University of Ottawa, Ottawa Hospital Research Institute, Ontario, Canada
| | - Iuliana Vaxman
- Division of Hematology, Mayo Clinic, Rochester, MN, USA.,Institute of Hematology, Davidoff Cancer Center, Rabin Medical Center, Petah-Tikvah, Israel.,Israel Sackler Faculty of Medicine Tel-Aviv University, Tel-Aviv, Israel
| | - Abdullah S Al Saleh
- Division of Hematology, Mayo Clinic, Rochester, MN, USA.,Division of Hematology and HSCT, King Saud bin Abdulaziz University for Health Sciences, Riyadh, Saudi Arabia
| | - Harsh Parmar
- Division of Hematology, John Theurer Cancer Center at Hackensack University, Hackensack, NJ, USA
| | | | | | - Martha Q Lacy
- Division of Hematology, Mayo Clinic, Rochester, MN, USA
| | - Morie A Gertz
- Division of Hematology, Mayo Clinic, Rochester, MN, USA
| | | | | | - David Dingli
- Division of Hematology, Mayo Clinic, Rochester, MN, USA
| | - Rahma Warsame
- Division of Hematology, Mayo Clinic, Rochester, MN, USA
| | | | | | | | - Eli Muchtar
- Division of Hematology, Mayo Clinic, Rochester, MN, USA
| | - John A Lust
- Division of Hematology, Mayo Clinic, Rochester, MN, USA
| | - Nelson Leung
- Division of Nephrology, Mayo Clinic, Rochester, MN, USA
| | - Robert A Kyle
- Division of Hematology, Mayo Clinic, Rochester, MN, USA
| | - David Murray
- Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN, USA
| | | | - Shaji Kumar
- Division of Hematology, Mayo Clinic, Rochester, MN, USA.
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26
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Report of the Survey Conducted by RCPAQAP on Current Practices for Beta-Migrating Paraprotein Reporting. Clin Biochem Rev 2021; 42:11-16. [PMID: 34305209 DOI: 10.33176/aacb-21-00001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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27
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Clavijo A, Ryan N, Xu H, Singh G. Measurement of Monoclonal Immunoglobulin Protein Concentration in Serum Protein Electrophoresis: Comparison of Automated vs Manual/Human Readings. Lab Med 2020; 51:252-258. [PMID: 32374393 DOI: 10.1093/labmed/lmz055] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
BACKGROUND Protein concentration of monoclonal immunoglobulin in plasma-cell myeloma/multiple myeloma provides an estimate of the tumor mass and allows for monitoring of the response to treatment. Accurate and reproducible estimates of the monoclonal immunoglobulin concentration are important for patient care. OBJECTIVE To address the optimum method for estimation of the concentration of monoclonal immunoglobulins. METHODS Serum protein electrophoresis and immunofixation electrophoresis were conducted by using the Helena SPIFE Touch instrument. Estimation of the protein concentration of monoclonal immunoglobulin in the gamma region by computer-assisted reading was compared with the reading by technologists and pathology residents, in 300 gels. The data were compared using t-testing and analysis of variance. RESULTS Computer-generated readings had a consistent positive bias. The correlation coefficient of the average reading by technologists and residents with the computer generated value was 0.997. The average positive bias by the computer reading was 0.29 g per dL. The intercept on the regression analysis was 0.22 g per dL. The reading by the computer was significantly higher than each of the human-interpreted readings. The readings by the 3 human groups were not significantly different amongst them. The main reason for the higher reading by the computer was inclusion of a greater area on the anodal size of the peak on the densitometric scan. CONCLUSIONS Human- and computer-interpreted readings of the protein concentration of monoclonal immunoglobulin have a high degree of correlation. The consistent positive bias by the computer reading occurred due to inclusion of a greater area of the densitometric scan on the anodal side of the peak. We suggest that vendors should adjust such computer programs to provide readings comparable to those generated by expert humans. We recommend manual delineation of the monoclonal peaks for measuring the concentration of monoclonal immunoglobulins.
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Affiliation(s)
- Alex Clavijo
- Department of Pathology, Medical College of Georgia at Augusta University, Augusta, GA
| | - Nathan Ryan
- Department of Pathology, Medical College of Georgia at Augusta University, Augusta, GA
| | - Hongyan Xu
- Department of Epidemiology and Bio-Statistics, Medical College of Georgia at Augusta University, Augusta, GA
| | - Gurmukh Singh
- Department of Pathology, Medical College of Georgia at Augusta University, Augusta, GA.,Division of Clinical Pathology, Medical College of Georgia at Augusta University, Augusta, GA
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Santockyte R, Puig O, Zheng N, Ouyang Z, Titsch C, Zhang YJ, Pillutla R, Zeng J. High-Throughput Therapeutic Antibody Interference-Free High-Resolution Mass Spectrometry Assay for Monitoring M-Proteins in Multiple Myeloma. Anal Chem 2020; 93:834-842. [DOI: 10.1021/acs.analchem.0c03357] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Rasa Santockyte
- Department of Translational Medicine, Bristol Myers Squibb, Route 206 and Province Line Road, Princeton, New Jersey 08543, United States
| | - Oscar Puig
- Department of Translational Medicine, Bristol Myers Squibb, Route 206 and Province Line Road, Princeton, New Jersey 08543, United States
| | - Naiyu Zheng
- Department of Translational Medicine, Bristol Myers Squibb, Route 206 and Province Line Road, Princeton, New Jersey 08543, United States
| | - Zheng Ouyang
- Department of Translational Medicine, Bristol Myers Squibb, Route 206 and Province Line Road, Princeton, New Jersey 08543, United States
| | - Craig Titsch
- Department of Translational Medicine, Bristol Myers Squibb, Route 206 and Province Line Road, Princeton, New Jersey 08543, United States
| | - Yang J. Zhang
- Department of Translational Medicine, Bristol Myers Squibb, Route 206 and Province Line Road, Princeton, New Jersey 08543, United States
| | - Renuka Pillutla
- Department of Translational Medicine, Bristol Myers Squibb, Route 206 and Province Line Road, Princeton, New Jersey 08543, United States
| | - Jianing Zeng
- Department of Translational Medicine, Bristol Myers Squibb, Route 206 and Province Line Road, Princeton, New Jersey 08543, United States
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29
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Singh G, Xu H. Light Chain Predominant Intact Immunoglobulin Monoclonal Gammopathy Disorders: Shorter Survival in Light Chain Predominant Multiple Myelomas. Lab Med 2020; 52:390-398. [PMID: 33180138 DOI: 10.1093/labmed/lmaa057] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND A proportion of intact immunoglobulin (Ig)-producing multiple myelomas (MMs) was observed to secrete much higher amounts of free light chains (LCs) than usual. OBJECTIVES To determine the change point between usual and LC-predominant intact Ig-secreting MMs and other monoclonal gammopathic manifestations and the biological significance of the observation. METHODS We conducted retrospective examination of laboratory findings in 386 MM, 27 smoldering MM, and 179 monoclonal gammopathy of undetermined significance (MGUS) cases that secreted intact Igs. We recorded the highest levels of involved serum free LC, highest ratio of involved to uninvolved LC, highest concentration of involved LC per g of monoclonal Ig, and highest value for ratio of involved to uninvolved LCs divided by the monoclonal Ig concentration. Each data set was sorted into kappa- and lambda LC-associated lesions. Length of time, in months, between diagnosis and last contact with the patients having myeloma was recorded. RESULTS Change point analysis of data revealed a subgroup of cases with distinctly higher levels of free LCs. In myelomas, including plasma cell leukemias, 16.4% of myelomas with kappa LCs and 22.3% of myelomas with lambda LCs, the LC secretion was distinctly higher than in the remaining cases, by a combination of 4 parameters, listed herein. Corresponding figures for smoldering myeloma (SMM) and monoclonal gammopathy of undetermined significance (MGUS) were 12.5, 27.3, 3.8, and 6.8, respectively. Ten of the 13 (77%) cases of plasma cell leukemia) and all cases of IgD myeloma (n = 4) showed excess secretion of serum free LCs. Among IgG and IgA myelomas, including plasma cell leukemias, the LC-predominant lesions had shorter survival, by an average of 22.5 months. CONCLUSIONS In total, 18.4% of MMs, including plasma cell leukemias, secrete distinctly higher amounts of serum free LCs than other intact Ig-secreting myelomas and confer significantly lower survival. Quantification of monoclonal serum free LCs may be useful in this subgroup in monitoring progress and potentially in ascertaining minimal residual disease. The findings also stress the need for separate criteria for kappa and lambda LC associated monoclonal gammopathic manifestations. The significantly shorter survival of patients with LC-predominant myelomas warrants consideration in prospective trials of treatments.
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Affiliation(s)
- Gurmukh Singh
- Division of Clinical Pathology, Department of Pathology, Augusta, GA
| | - Hongyan Xu
- Division of Biostatistics and Data Sciences, Medical College of Georgia at Augusta University, Augusta, GA
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30
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Singh G. Serum and Urine Protein Electrophoresis and Serum-Free Light Chain Assays in the Diagnosis and Monitoring of Monoclonal Gammopathies. J Appl Lab Med 2020; 5:1358-1371. [PMID: 33150391 DOI: 10.1093/jalm/jfaa153] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2020] [Accepted: 08/14/2020] [Indexed: 12/14/2022]
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.
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Affiliation(s)
- Gurmukh Singh
- Medical College of Georgia, Augusta University, Augusta, GA
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31
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Zajec M, Langerhorst P, VanDuijn MM, Gloerich J, Russcher H, van Gool AJ, Luider TM, Joosten I, de Rijke YB, Jacobs JFM. Mass Spectrometry for Identification, Monitoring, and Minimal Residual Disease Detection of M-Proteins. Clin Chem 2020; 66:421-433. [PMID: 32031591 DOI: 10.1093/clinchem/hvz041] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2019] [Accepted: 09/13/2019] [Indexed: 12/20/2022]
Abstract
BACKGROUND Monoclonal gammopathies (MGs) are plasma cell disorders defined by the clonal expansion of plasma cells, resulting in the characteristic excretion of a monoclonal immunoglobulin (M-protein). M-protein detection and quantification are integral parts of the diagnosis and monitoring of MGs. Novel treatment modalities impose new challenges on the traditional electrophoretic and immunochemical methods that are routinely used for M-protein diagnostics, such as interferences from therapeutic monoclonal antibodies and the need for increased analytical sensitivity to measure minimal residual disease. CONTENT Mass spectrometry (MS) is ideally suited to accurate mass measurements or targeted measurement of unique clonotypic peptide fragments. Based on these features, MS-based methods allow for the analytically sensitive measurement of the patient-specific M-protein. SUMMARY This review provides a comprehensive overview of the MS methods that have been developed recently to detect, characterize, and quantify M-proteins. The advantages and disadvantages of using these techniques in clinical practice and the impact they will have on the management of patients with MGs are discussed.
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Affiliation(s)
- M Zajec
- Department of Clinical Chemistry, Erasmus MC, University Medical Center Rotterdam, Rotterdam, the Netherlands.,Department of Neurology, Erasmus MC, University Medical Center Rotterdam, Rotterdam, the Netherlands
| | - P Langerhorst
- Department of Laboratory Medicine, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, the Netherlands
| | - M M VanDuijn
- Department of Neurology, Erasmus MC, University Medical Center Rotterdam, Rotterdam, the Netherlands
| | - J Gloerich
- Department of Laboratory Medicine, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, the Netherlands
| | - H Russcher
- Department of Clinical Chemistry, Erasmus MC, University Medical Center Rotterdam, Rotterdam, the Netherlands
| | - A J van Gool
- Department of Laboratory Medicine, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, the Netherlands
| | - T M Luider
- Department of Neurology, Erasmus MC, University Medical Center Rotterdam, Rotterdam, the Netherlands
| | - I Joosten
- Department of Laboratory Medicine, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Y B de Rijke
- Department of Clinical Chemistry, Erasmus MC, University Medical Center Rotterdam, Rotterdam, the Netherlands
| | - J F M Jacobs
- Department of Laboratory Medicine, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, the Netherlands
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Vertical cutoff methods in serum protein electrophoresis for the measurement of monoclonal protein concentrations: Which is best? Clin Chim Acta 2020; 510:573-580. [PMID: 32791139 DOI: 10.1016/j.cca.2020.07.051] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2020] [Revised: 07/26/2020] [Accepted: 07/26/2020] [Indexed: 11/22/2022]
Abstract
BACKGROUND Monoclonal protein (M-protein) concentrations are measured by serum protein electrophoresis (SPE). Two methods are used for demarcating the M-protein area in the electropherogram: perpendicular drop (PD) and tangent skimming (TS). The aim of this study was tocompare both methods and to establish which is the most accurate and precise. METHODS We studied 24 sera containing M-protein (5-44 g/L). The systematic error (SE) was evaluated in a dilution series of 12 sera. Within-day, between-day, and interobserver variability were assessed. SPE was performed by capillary and agarose gel electrophoresis. M-protein concentrations were measured using both cutoff methods. RESULTS The PD method shows a constant SE ranged 1.00-2.27 g/L, while constant SE for TS is ranged -0.30--0.57 g/L. None of the cutoff methods or electrophoretic methods showed a proportional SE, with the exception of the TS method in capillary electrophoresis for β-migrating M-protein. The PD method was more precise than the TS method in all three estimates of imprecision. An increased CV for concentrations < 10 g/L in between-day imprecision was observed with the TS method. Interobserver imprecision was greater for M-protein concentrations < 17 g/L for both cutoff methods (14.85%, 26.42% respectively). CONCLUSIONS Despite being less precise, the TS method provides a more accurate measurement of M-protein concentration.
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Arnold JE, Camus MS, Freeman KP, Giori L, Hooijberg EH, Jeffery U, Korchia J, Meindel MJ, Moore AR, Sisson SC, Vap LM, Cook JR. ASVCP Guidelines: Principles of Quality Assurance and Standards for Veterinary Clinical Pathology (version 3.0): Developed by the American Society for Veterinary Clinical Pathology's (ASVCP) Quality Assurance and Laboratory Standards (QALS) Committee. Vet Clin Pathol 2020; 48:542-618. [PMID: 31889337 DOI: 10.1111/vcp.12810] [Citation(s) in RCA: 67] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
| | - Melinda S Camus
- Department of Pathology, University of Georgia College of Veterinary Medicine, Athens, GA, USA
| | | | - Luca Giori
- Department of Biomedical and Diagnostic Sciences, University of Tennessee College of Veterinary Medicine, Knoxville, TN, USA
| | - Emma H Hooijberg
- Department of Companion Animal Clinical Studies, Faculty of Veterinary Science, University of Pretoria, Pretoria, South Africa
| | - Unity Jeffery
- Department of Veterinary Pathobiology, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX, USA
| | - Jérémie Korchia
- Texas A&M Veterinary Medical Diagnostic Laboratory, College Station, TX, USA
| | | | - A Russell Moore
- Department of Microbiology, Immunology and Pathology, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, CO, USA
| | - Sandra C Sisson
- Cornell University College of Veterinary Medicine, Ithaca, NY, USA
| | - Linda M Vap
- Department of Microbiology, Immunology and Pathology, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, CO, USA
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Plebani M. New insights on the analytical performances for detecting and quantifying monoclonal proteins. Clin Chem Lab Med 2020; 58:457-459. [DOI: 10.1515/cclm-2019-1266] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/02/2023]
Affiliation(s)
- Mario Plebani
- Department of Laboratory, Medicine , University-Hospital of Padova , Via Giustiniani 2 , Padova 35128 , Italy , Phone: +39 0498212792, Fax: +39 049663240
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Šegulja D, Matišić D, Barišić K, Rogić D. Verification study of free light chains assays on reagent-optimized analysers. Biochem Med (Zagreb) 2019; 29:030709. [PMID: 31624462 PMCID: PMC6784423 DOI: 10.11613/bm.2019.030709] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2019] [Accepted: 07/14/2019] [Indexed: 11/01/2022] Open
Abstract
Introduction: Our aim was to compare analytical specifications of two assays (monoclonal vs. polyclonal) for free light chains (FLCs) quantification optimized for two different analytical platforms, nephelometer ProSpec (Siemens, Erlangen, Germany) and turbidimetric analyser Optilite (The Binding Site, Birmingham, UK). Materials and methods: The evaluation included verification of the precision, repeatability and reproducibility, estimation of accuracy and method comparison study with 37 serum samples of haematological patients. Kappa and lambda FLC were measured in each sample by both methods and kappa/lambda ratio was calculated. Results: Results show satisfactory precision of both methods with coefficients of variation for ProSpec of CVwr = 2.20% and CVbr = 3.44%, and for Optilite CVwr = 2.82% and CVbr = 4.15%. Estimated bias for FLC lambda was higher on the ProSpec analyser, but bias for FLC kappa was higher on the Optilite analyser. Correlation coefficients were 0.98; P < 0.001 for FLC kappa and 0.97; P < 0.001 for FLC lambda. Considering normal/pathological FLC ratio moderate agreement within assays was detected (κ = 0.621). When the results were categorized according to criteria for progressive disease, 4/37 (0.10) cases were differently classified. Lambda FLC values by Optilite in three samples with monoclonal FLC lambda were more than twelve times higher than by ProSpec. A 25% difference in FLC ratio was detected in 16/37 (0.43) and 50% difference in 13/37 (0.35) patients. Conclusions: All manufacturers’ precision claims could not be achieved in the verification study. The comparison of results to biological variations data showed that coefficients of variations are acceptable for both assays. The assays should not be used interchangeably in haematological patients.
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Affiliation(s)
- Dragana Šegulja
- Department of Laboratory Diagnostics, University Hospital Centre Zagreb, Zagreb, Croatia
| | - Danica Matišić
- Department of Laboratory Diagnostics, University Hospital Centre Zagreb, Zagreb, Croatia
| | - Karmela Barišić
- Department of Medical Biochemistry and Hematology, Faculty of Pharmacy and Biochemistry, University of Zagreb, Zagreb, Croatia
| | - Dunja Rogić
- Department of Laboratory Diagnostics, University Hospital Centre Zagreb, Zagreb, Croatia
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Harris AD, Rout E, Avery A, Bolte D, Belling-Kelly E, Moore AR. Validation and method comparison of the use of densitometry to quantify monoclonal proteins in canine sera. Vet Clin Pathol 2019; 48 Suppl 1:78-87. [PMID: 31410878 DOI: 10.1111/vcp.12766] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2019] [Revised: 03/23/2019] [Accepted: 04/17/2019] [Indexed: 11/30/2022]
Abstract
BACKGROUND Densitometric quantitation using serum protein electrophoresis (SPE) is used to monitor monoclonal proteins (M-proteins) in human patients but has not been validated in the dog. Serum globulin concentrations, species-specific radial immunodiffusion (RID), and ELISAs are currently used in veterinary medicine. OBJECTIVE We aimed to compare four methods that quantify M-proteins using densitometry and biuret protein (dM-protein) measurements. We also validated the best performing method and compared it with the RID and ELISA methods for measuring canine serum M-protein. METHOD Serum from six normal dogs and 83 serum samples from 46 dogs with confirmed monoclonal gammopathies were used. A spike and recovery experiment with purified monoclonal IgG and IgM, inter-run and intra-run variability, linearity under dilution, and lower limit of detection were performed. Results of commercial canine RID and ELISA kits for total class-specific immunoglobulin were compared with dM-proteins. RESULTS The corrected perpendicular drop gating method had <20% error for IgG/γ-globulin and IgM/β-globulin M-protein quantifications. Linearity (r > .99), intra-run CV (1.1%-2.3%), and inter-run CVs (2.0%-3.5%) were acceptable. Correlation between the RID and densitometry results ranged from r = .25 to r = .88, depending on the class. The RID result was greater than that of the biuret total protein in 26/63 (41%) IgA cases. A panel of IgG, IgA, and IgM RIDs failed to correctly identify an IgM paraproteinemia in 6/6 (100%) cases. Densitometry was not comparable with any other tested method. CONCLUSION Densitometric quantitation is a valid technique for measuring M-proteins in the β- and γ-globulin regions. Immunotyping via RID using the tested kit does not appear to detect IgM. Densitometry is recommended for measuring M-proteins in canine patients.
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Affiliation(s)
- Adam Dugger Harris
- Department of Microbiology, Immunology, and Pathology, College of Veterinary Medicine and Biomedical Science, Colorado State University, Fort Collins, CO, USA
| | - Emily Rout
- Department of Microbiology, Immunology, and Pathology, College of Veterinary Medicine and Biomedical Science, Colorado State University, Fort Collins, CO, USA
| | - Anne Avery
- Department of Microbiology, Immunology, and Pathology, College of Veterinary Medicine and Biomedical Science, Colorado State University, Fort Collins, CO, USA
| | - Denise Bolte
- Department of Microbiology, Immunology, and Pathology, College of Veterinary Medicine and Biomedical Science, Colorado State University, Fort Collins, CO, USA
| | - Erica Belling-Kelly
- Population Medicine and Diagnostic Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY, USA
| | - A Russell Moore
- Department of Microbiology, Immunology, and Pathology, College of Veterinary Medicine and Biomedical Science, Colorado State University, Fort Collins, CO, USA
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Moore AR, Avery PR. Protein characterization using electrophoresis and immunofixation; a case-based review of dogs and cats. Vet Clin Pathol 2019; 48 Suppl 1:29-44. [PMID: 31270837 DOI: 10.1111/vcp.12760] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2018] [Revised: 12/05/2018] [Accepted: 01/16/2019] [Indexed: 12/22/2022]
Abstract
Protein electrophoresis and immunotyping can be a useful adjunct to the standard biochemical techniques for characterizing serum and urine proteins. This paper reviews currently available and commonly used methods for diagnostic protein electrophoresis, including both agarose gel and capillary zone electrophoretic techniques and total protein assessments. Immunofixation and immunosubtraction methods for identification of immunoglobulin location and class are also presented. Practical application of quality assurance and quality control strategies in compliance with American Society of Veterinary Clinical Pathology (ASVCP) best practices are discussed. Commonly encountered serum and urine electrophoretic diagnostic patterns, including electrophoretically normal, acute-phase protein responses, polyclonal gammopathies, restricted polyclonal/oligoclonal gammopathies, paraproteinemias (monoclonal or biclonal gammopathies), and Bence-Jones proteinurias are also reviewed using relevant case material. Cases in which immunofixation electrophoresis are particularly useful are highlighted, and methodologies to more accurately quantify serum monoclonal proteins (M-proteins), monitoring tests commonly used in human medicine, are discussed.
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Affiliation(s)
- A Russell Moore
- Department of Microbiology, Immunology, and Pathology, College of Veterinary Medicine and Biomedical Science, Colorado State University, Fort Collins, Colorado
| | - Paul R Avery
- Department of Microbiology, Immunology, and Pathology, College of Veterinary Medicine and Biomedical Science, Colorado State University, Fort Collins, Colorado
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Yu XC, Su W, Zhuang JL. [The value of serum heavy/light chain immunoassay to assess therapeutic response in patients with multiple myeloma]. ZHONGHUA XUE YE XUE ZA ZHI = ZHONGHUA XUEYEXUE ZAZHI 2019; 39:281-285. [PMID: 29779321 PMCID: PMC7342143 DOI: 10.3760/cma.j.issn.0253-2727.2018.04.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Objective: To assess the value of immunoglobulin heavy/light chain (HLC) immunoassay on therapeutic response in patients with multiple myeloma(MM). Methods: A total of 45 newly diagnosed MM patients were retrospectively enrolled in Peking Union Medical College Hospital from 2013 to 2016, whose 115 serum samples were consecutively collected. HLC was tested to evaluate response and compare with other methods for M protein detection. Results: ①There were 30 males and 15 females in total of whom the monoclonal immunoglobulin was IgG in 27 (IgGκ∶IgGλ 12∶15) and IgA (IgAκ∶IgAλ 9∶9) in 18. The arerage age of the studied population was 59 (range 43-80) . ② In 34 patients with serum sample at diagnosis, 32 (94.1%) had abnormal HLC ratio (rHLC) while 2 patients with IgG had normal rHLC. The percentages of abnormal rHLC was 81.8% (18/22) at partial response、50.0%(9/18) at very good complete response and 16.0%(4/25) at complete response. ③In 25 patients reaching CR, there were 13 with IgG and 12 with IgA. 4 patients equally split of IgG and IgA had abnormal rHLC at complete response. ④By monitoring the rHLC of some patients consecutively, we found that the remission of rHLC was to some extent behind the remission of SPE and IEF, or even rFLC. Conclusion: Immunoglobulin HLC detection is one feasible method for minimal residual disease detection.
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Affiliation(s)
| | | | - J L Zhuang
- Department of Hematology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100730, China
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Abstract
Laboratory testing plays an essential role in the diagnosis and management of patients with multiple myeloma. A variety of chemistry and molecular assays are routinely used to monitor patient progress, response to treatment and relapse. Here, we have reviewed current literature and core guidelines on the details of laboratory testing in myeloma-related investigations. This includes the use and value of protein electrophoresis, serum free light chain and cytogenetic testing. Furthermore, we discuss other traditional chemistry assays essential to myeloma investigation, and potential interferences that may arise due to the disease nature of myeloma, that is, the presence of a monoclonal immunoglobulin. Finally, we discuss the importance of communication in protein electrophoresis results, where laboratorians are required to relate clinically relevant myeloma-relevant information to the ordering physician on the background of a complex pattern of serum or urine proteins. Laboratory testing in myeloma-related investigation relies on several traditional chemistry assays. However, we anticipate new tests and technologies to become available in the future with improved analytical sensitivity, as well as improved clinical sensitivity in identifying patients who are at high risk of progression to multiple myeloma.
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Affiliation(s)
| | - Ronald A Booth
- Division of Biochemistry, The Ottawa Hospital, University of Ottawa, Ottawa, ON, Canada; Department of Pathology and Laboratory Medicine, University of Ottawa, Ottawa, ON, Canada
| | - Kristin Hauff
- Interior Health Corporate Office, Kelowna, BC, Canada
| | - Philip Berardi
- Ottawa Hospital Research Institute (OHRI), Ottawa, ON, Canada; Division of Anatomical Pathology, The Ottawa Hospital/University of Ottawa, Ottawa, ON, Canada
| | - Alissa Visram
- Division of Haematology, The Ottawa Hospital General Campus, Ottawa, ON, Canada
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Schroeder LF, Huls F, Williams CL, Li SH, Keren DF. A Novel Approach to Estimating M-Protein Concentration: Capillary Electrophoresis Quantitative Immunosubtraction. J Appl Lab Med 2018; 2:914-919. [PMID: 33636829 DOI: 10.1373/jalm.2017.024950] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2017] [Accepted: 11/27/2017] [Indexed: 11/06/2022]
Abstract
INTRODUCTION M-protein quantification is routinely performed by demarcating serum protein electrophoresis (SPE) regions. However, quantification of β-migrating M-protein is hindered by overlapping nonimmunoglobulin protein. Immunosubtraction (ISUB) on capillary electrophoresis is a method currently used qualitatively to subtract out (and therefore highlight) immunoglobulin isotypes in serum, thus reducing the masking effect of normal serum proteins. This study expands on traditional ISUB by developing a quantitative immunosubtraction (qIS) methodology. METHODS qIS is achieved by estimating the monoclonal class-specific immunoglobulin contribution to the SPE region containing the M-protein. We conducted a recovery study by use of serial dilutions from 3 patients with β-region M-proteins (n = 22), performing SPE and ISUB on each dilution. We visualized the difference between the ISUB electrophoresis trace and the involved ISUB isotype-subtracted trace to distinguish M-protein and background polyclonal immunoglobulins, which was demarcated independently by 3 pathologists. The M-protein contribution to the β-region was calculated and applied to the β-region protein concentration producing the quantitative M-protein concentration, while minimizing contamination by nonimmunoglobulin or polyclonal immunoglobulin proteins. RESULTS Using a quality target of 25% error, we determined that our analytical measurable range spanned the maximum concentration tested (0.81 g/dL) to 0.05 g/dL. Passing-Bablok regression between qIS and the expected M-protein produced a slope of 1.04 (95% CI, 0.94-1.09), r = 0.99. Total CV was 4.8% and intraclass correlation between pathologists was 0.998. DISCUSSION qIS promises quantification of β-migrating M-proteins at concentrations an order of magnitude lower than traditional SPE methodology, allowing earlier detection of increasing or decreasing M-protein.
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Affiliation(s)
- Lee F Schroeder
- Department of Pathology, University of Michigan, Ann Arbor, MI
| | - Forest Huls
- Department of Pathology, University of Michigan, Ann Arbor, MI
| | | | - Shih-Hon Li
- Department of Pathology, University of Michigan, Ann Arbor, MI
| | - David F Keren
- Department of Pathology, University of Michigan, Ann Arbor, MI
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Willrich MA, Murray DL, Kyle RA. Laboratory testing for monoclonal gammopathies: Focus on monoclonal gammopathy of undetermined significance and smoldering multiple myeloma. Clin Biochem 2018; 51:38-47. [DOI: 10.1016/j.clinbiochem.2017.05.001] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2016] [Revised: 05/01/2017] [Accepted: 05/03/2017] [Indexed: 02/07/2023]
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Booth RA, McCudden CR, Balion CM, Blasutig IM, Bouhtiauy I, Rodriguez-Capote K, Catomeris P, Chan PC, Chen Y, Collier C, Hauff K, Kalra J, Li D, Lin DC, Lou AH, Meng QH, Morrison T, Pasic MD, Qureshi M, Randell E, Sohn KY, Thakur V, Thomas D, Thoni A, Tomalty C, Yang L, Zamkanei M. Candidate recommendations for protein electrophoresis reporting from the Canadian Society of Clinical Chemists Monoclonal Gammopathy Working Group. Clin Biochem 2018; 51:10-20. [DOI: 10.1016/j.clinbiochem.2017.10.013] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2017] [Revised: 10/18/2017] [Accepted: 10/18/2017] [Indexed: 11/26/2022]
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Tate JR, Keren DF, Mollee P. A global call to arms for clinical laboratories – Harmonised quantification and reporting of monoclonal proteins. Clin Biochem 2018; 51:4-9. [DOI: 10.1016/j.clinbiochem.2017.11.009] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2017] [Revised: 11/05/2017] [Accepted: 11/13/2017] [Indexed: 12/11/2022]
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Regeniter A, Siede W. Peaks and tails: Evaluation of irregularities in capillary serum protein electrophoresis. Clin Biochem 2018; 51:48-55. [DOI: 10.1016/j.clinbiochem.2017.09.017] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2017] [Revised: 09/20/2017] [Accepted: 09/20/2017] [Indexed: 10/18/2022]
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Genzen JR, Murray DL, Abel G, Meng QH, Baltaro RJ, Rhoads DD, Delgado JC, Souers RJ, Bashleben C, Keren DF, Ansari MQ. Screening and Diagnosis of Monoclonal Gammopathies: An International Survey of Laboratory Practice. Arch Pathol Lab Med 2017; 142:507-515. [DOI: 10.5858/arpa.2017-0128-cp] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Context.—
Serum tests used for the screening and diagnosis of monoclonal gammopathies include serum protein electrophoresis (SPE; agarose gel or capillary zone), immunofixation (IFE) and immunosubtraction capillary electrophoresis, serum free light chains, quantitative immunoglobulins, and heavy/light–chain combinations. Urine protein electrophoresis and urine IFE may also be used to identify Bence-Jones proteinuria.
Objective.—
To assess current laboratory practice for monoclonal gammopathy testing.
Design.—
In April 2016, a voluntary questionnaire was distributed to 923 laboratories participating in a protein electrophoresis proficiency testing survey.
Results.—
Seven hundred seventy-four laboratories from 38 countries and regions completed the questionnaire (83.9% response rate; 774 of 923). The majority of participants (68.6%; 520 of 758) used agarose gel electrophoresis as their SPE method, whereas 31.4% (238 of 758) used capillary zone electrophoresis. The most common test approaches used in screening were SPE with reflex to IFE/immunosubtraction capillary electrophoresis (39.3%; 299 of 760); SPE only (19.1%; 145 of 760); SPE and IFE or immunosubtraction capillary electrophoresis (13.9%; 106 of 760); and SPE with IFE, serum free light chain, and quantitative immunoglobulins (11.8%; 90 of 760). Only 39.8% (305 of 767) of laboratories offered panel testing for ordering convenience. Although SPE was used by most laboratories in diagnosing new cases of myeloma, when laboratories reported the primary test used to follow patients with monoclonal gammopathy, only 55.7% (403 of 724) chose SPE, with the next most common selections being IFE (18.9%; 137 of 724), serum free light chain (11.7%; 85 of 724), and immunosubtraction capillary electrophoresis (2.1%; 15 of 724).
Conclusions.—
Ordering and testing practices for the screening and diagnosis of monoclonal gammopathy vary widely across laboratories. Improving utilization management and report content, as well as recognition and development of laboratory-directed testing guidelines, may serve to enhance the clinical value of testing.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | | | - Mohammad Q. Ansari
- From the Department of Pathology, University of Utah, Salt Lake City, and ARUP Laboratories, Salt Lake City, Utah (Drs Genzen and Delgado); the Department of Laboratory Medicine, Mayo Clinic, Rochester, Minnesota (Dr Murray); the Department of Laboratory Medicine, Lahey Hospital & Medical Center, Burlington, Massachusetts (Dr Abel); the Department of Laboratory Medicine, University of Texas MD An
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Mills JR, Kohlhagen MC, Dasari S, Vanderboom PM, Kyle RA, Katzmann JA, Willrich MAV, Barnidge DR, Dispenzieri A, Murray DL. Comprehensive Assessment of M-Proteins Using Nanobody Enrichment Coupled to MALDI-TOF Mass Spectrometry. Clin Chem 2016; 62:1334-44. [DOI: 10.1373/clinchem.2015.253740] [Citation(s) in RCA: 98] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2015] [Accepted: 07/18/2016] [Indexed: 01/20/2023]
Abstract
Abstract
BACKGROUND
Electrophoretic separation of serum and urine proteins has played a central role in diagnosing and monitoring plasma cell disorders. Despite limitations in resolution and analytical sensitivity, plus the necessity for adjunct methods, protein gel electrophoresis and immunofixation electrophoresis (IFE) remain front-line tests.
METHODS
We developed a MALDI mass spectrometry–based assay that was simple to perform, automatable, analytically sensitive, and applicable to analyzing the wide variety of monoclonal proteins (M-proteins) encountered clinically. This assay, called MASS-FIX, used the unique molecular mass signatures of the different Ig isotypes in combination with nanobody immunoenrichment to generate information-rich mass spectra from which M-proteins could be identified, isotyped, and quantified. The performance of MASS-FIX was compared to current gel-based electrophoresis assays.
RESULTS
MASS-FIX detected all M-proteins that were detectable by urine or serum protein electrophoresis. In serial dilution studies, MASS-FIX was more analytically sensitive than IFE. For patient samples, MASS-FIX provided the same primary isotype information for 98% of serum M-proteins (n = 152) and 95% of urine M-proteins (n = 55). MASS-FIX accurately quantified M-protein to <1 g/dL, with reduced bias as compared to protein electrophoresis. Intraassay and interassay CVs were <20% across all samples having M-protein concentrations >0.045 g/dL, with the ability to detect M-proteins <0.01 g/dL. In addition, MASS-FIX could simultaneously measure κ:λ light chain ratios for IgG, IgA, and IgM. Retrospective serial monitoring of patients with myeloma posttreatment demonstrated that MASS-FIX provided equivalent quantitative information to either protein electrophoresis or the Hevylite™ assay.
CONCLUSIONS
MASS-FIX can advance how plasma cell disorders are screened, diagnosed, and monitored.
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Affiliation(s)
- John R Mills
- Departments of Laboratory Medicine and Pathology
| | | | | | | | - Robert A Kyle
- Division of Hematology, Department of Medicine, Mayo Clinic, Rochester, MN
| | | | | | | | - Angela Dispenzieri
- Division of Hematology, Department of Medicine, Mayo Clinic, Rochester, MN
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