1
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Griffiths M, Cheng PL, Wang XY, Schneider R, Kulasingam V. Comparison of 2 Serum Free Light Chain Assays with Creatinine Normal and Abnormal Populations Demonstrates the Need for Standardization. J Appl Lab Med 2024; 9:978-988. [PMID: 38973026 DOI: 10.1093/jalm/jfae065] [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: 12/21/2023] [Accepted: 05/22/2024] [Indexed: 07/09/2024]
Abstract
BACKGROUND The objective of this study was to compare The Binding Site's Freelite on Optilite and Diazyme's Kappa/Lambda free light chains (K/L FLC) on Abbott Architect c8000 with healthy and renal insufficient populations and to evaluate their respective reference intervals for serum free light chains (sFLCs). METHODS Two hundred sixty serum samples were measured for creatinine and sFLCs by both assays and a subset by immunofixation electrophoresis. Verification of manufacturer-defined reference intervals was assessed. RESULTS Kappa free light chains (KFLC) showed excellent correlation of 0.998 R2 with a slope of 0.73. For Lambda free light chains (LFLC), an acceptable correlation of 0.953 R2 was found with a slope of 1.50 as well as a skewness-based difference with a -12.70 intercept. Healthy estimated glomerular filtration rate (eGFR) ≥60 reference interval verification of central 95% could not be confirmed for either Freelite or Diazyme although LFLC was much closer than KFLC for both assays with Freelite KFLC recovering only 37% of values within reference interval claims. The K/L FLC ratio did not meet 100% claim for both Freelite (91%) and Diazyme (95%) among those with eGFR ≥60. Samples with eGFR ≤59 had increasingly higher levels of KFLC and LFLC for both assays. When comparing worsening eGFR status, Freelite recovered increasingly higher ratios while Diazyme recovered increasingly lower ratios. CONCLUSIONS Healthy reference intervals could not be verified for either Freelite or Diazyme. Renal reference intervals for Freelite are currently warranted while they are not recommended for Diazyme. The differences between these 2 assays can be minimized by standardization efforts such as recalibration.
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Affiliation(s)
| | - Pow Lee Cheng
- Division of Clinical Biochemistry, University Health Network, Toronto, Canada
| | - Xiao Yan Wang
- Division of Clinical Biochemistry, University Health Network, Toronto, Canada
| | | | - Vathany Kulasingam
- Division of Clinical Biochemistry, University Health Network, Toronto, Canada
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Canada
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2
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Zeman D, Štork M, Švancarová L, Borský M, Pospíšilová M, Adam Z, Beňovská M, Pour L. Isoelectric focusing followed by affinity immunoblotting to detect monoclonal free light chains in monoclonal gammopathies: Comparison with immunofixation electrophoresis and free light chain ratio. Ann Clin Biochem 2024; 61:291-302. [PMID: 38073192 DOI: 10.1177/00045632231221439] [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] [Indexed: 02/08/2024]
Abstract
BACKGROUND Isoelectric focusing (IEF) is a method with an exquisite resolution, and coupled with affinity immunoblotting (AIB), it can provide superior sensitivity to detect monoclonal free light chains (FLC). METHODS We tested the hypothesis that IEF/AIB is more sensitive and specific for monoclonal FLC detection in serum and urine samples than conventional methods, that is, electrophoresis (ELP), immunofixation (IF) and serum FLC ratio assessment. Investigation included 107 samples of 68 patients, among which 21 multiple myeloma patients were recently tested for minimal residual disease and 18 patients with AL amyloidosis. RESULTS Monoclonal FLC were detected by IEF/AIB in 37% of serum samples negative for monoclonal FLC on ELP/IF. As for urine samples, significant advantage of the IEF/AIB over ELP/IF was not demonstrated. Considering both serum and urine results, IEF/AIB definitely revealed monoclonal FLC in 20/83 (24%) of ELP/IF-negative samples. FLC ratio was abnormally high (>1.65) in all 11 patients definitely positive for monoclonal FLC kappa by IEF/AIB but also in 16/47 (34%) IEF/AIB-negative samples. Abnormally low values (<0.26) were found only in 10/28 samples (36%) positive for monoclonal FLC lambda. Appropriate use of renal FLC ratio reference range reduced the number of presumably false positives (6/47, i.e. 13%) but not false negatives (17/28, i.e. 61%). CONCLUSIONS The IEF/AIB method is more sensitive than IF and might be used in patients with negative IF results before deciding whether to proceed to minimal residual disease testing.
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Affiliation(s)
- David Zeman
- Department of Laboratory Medicine, Division of Clinical Biochemistry, University Hospital Brno, Brno, Czech Republic
- Department of Laboratory Methods, Faculty of Medicine, Masaryk University, Brno, Czech Republic
| | - Martin Štork
- Department of Internal Medicine, Haematology and Oncology, University Hospital Brno and Faculty of Medicine, Masaryk University, Brno, Czech Republic
| | - Lenka Švancarová
- Department of Laboratory Methods, Faculty of Medicine, Masaryk University, Brno, Czech Republic
| | - Marek Borský
- Department of Internal Medicine, Haematology and Oncology, University Hospital Brno and Faculty of Medicine, Masaryk University, Brno, Czech Republic
| | - Michaela Pospíšilová
- Department of Laboratory Medicine, Division of Clinical Biochemistry, University Hospital Brno, Brno, Czech Republic
- Department of Laboratory Methods, Faculty of Medicine, Masaryk University, Brno, Czech Republic
| | - Zdeněk Adam
- Department of Internal Medicine, Haematology and Oncology, University Hospital Brno and Faculty of Medicine, Masaryk University, Brno, Czech Republic
| | - Miroslava Beňovská
- Department of Laboratory Medicine, Division of Clinical Biochemistry, University Hospital Brno, Brno, Czech Republic
- Department of Laboratory Methods, Faculty of Medicine, Masaryk University, Brno, Czech Republic
| | - Luděk Pour
- Department of Internal Medicine, Haematology and Oncology, University Hospital Brno and Faculty of Medicine, Masaryk University, Brno, Czech Republic
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3
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Ye Mon M, Ufondu O, Mortley S, Bollag RJ, Singh G. Urine Immunofixation Electrophoresis for Diagnosis of Monoclonal Gammopathy: Evaluation of Methods for Urine Concentration. J Appl Lab Med 2024; 9:350-356. [PMID: 38180079 DOI: 10.1093/jalm/jfad113] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2023] [Accepted: 10/16/2023] [Indexed: 01/06/2024]
Abstract
BACKGROUND Examination of urine by immunofixation electrophoresis (UIFE) is one of the tests recommended for screening and monitoring of monoclonal gammopathies, especially multiple myeloma. Unlike the serum free light chain measurement, a positive result on urine immunofixation is diagnostic for monoclonal immunoglobulin light chains. Urine is usually concentrated, generally by membrane filtration, prior to electrophoresis. METHODS Alternative methods to membrane filtration for urine concentration were examined. Residual urine specimens submitted for urine protein electrophoresis were concentrated by precipitation of the proteins by ammonium sulfate salt precipitation, precipitation with ethanol and acetonitrile, and by desiccation. The concentrated specimens were subjected to immunofixation electrophoresis using antisera to free light chains (FLC). The results were compared with those from conventional immunofixation electrophoresis using specimens concentrated by membrane filtration. RESULTS Ammonium sulfate, ethanol, and acetonitrile precipitation results were less than satisfactory. Concentration by desiccation provided results comparable, if not better than, those by membrane filtration and conventional UIFE. The cost of desiccation is minimal compared to more than $5.00/specimen cost of concentration by membrane filtration. The differences in the results with conventional UIFE and the method described here are likely due to (a) variability in the reactivity of different antisera to free monoclonal light chains, and (b) obscuration of monoclonal free light chains by co-migration with intact immunoglobulin monoclonal proteins. CONCLUSIONS Concentrating urine by desiccation for immunofixation electrophoresis is technically simple, inexpensive, and provides results comparable to concentrating by membrane filtration. Using FLC provides a more sensitive assay than using conventional antisera.
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Affiliation(s)
- May Ye Mon
- Department of Pathology, Medical College of Georgia at Augusta University, Augusta, GA, United States
| | - Obiora Ufondu
- Department of Pathology, Medical College of Georgia at Augusta University, Augusta, GA, United States
| | - Shanee Mortley
- Department of Pathology, Medical College of Georgia at Augusta University, Augusta, GA, United States
| | - Roni J Bollag
- Department of Pathology, Medical College of Georgia at Augusta University, Augusta, GA, United States
| | - Gurmukh Singh
- Department of Pathology, Medical College of Georgia at Augusta University, Augusta, GA, United States
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4
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Singh G, Cotter T, Ye Mon M, Xu H, Bollag RJ. Quantification of Free Immunoglobulin Light Chains in Urine. J Appl Lab Med 2023; 8:1101-1114. [PMID: 37725944 DOI: 10.1093/jalm/jfad055] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2023] [Accepted: 06/26/2023] [Indexed: 09/21/2023]
Abstract
BACKGROUND The serum-free immunoglobulin light chain assay has been recommended as a screening test for monoclonal gammopathy. We evaluated the usefulness of urine free immunoglobulin light concentration for selection of specimens for immunofixation electrophoresis. METHODS Using kits from The Binding Site for Freelite ®, we validated examination of urine for measuring free κ and λ light chains. The results of urine free light chain concentrations were evaluated to ascertain if the results could be used to reduce the number of specimens requiring urine protein immunofixation electrophoresis. RESULTS In the 515 specimens examined, there was no evidence of monoclonal gammopathy or history of monoclonal gammopathy in 331. Monoclonal κ or λ light chains were detectable in 42 and 30 specimens, respectively. There was history of κ or λ chain associated monoclonal gammopathy in 62 and 50 patients, respectively. In the 38 monoclonal κ positive urine specimens, with light chain data, κ/λ ratio was >5.83 in all specimens. In 27 specimens positive for monoclonal λ light chains, with light chain data, the urine λ/κ ratio was > 0.17 in 24 of 27 specimens and > 0.041 in all specimens. In patients without monoclonal gammopathy all specimens had a κ/λ ratio of >5.83 or λ/κ ratio >0.17. CONCLUSIONS The Freelite ® assay from The Binding Site is suitable for quantification of free light chains in urine. In patients with known history of monoclonal gammopathy, urine immunofixation electrophoresis may be omitted in specimens with κ/λ ratio of <5.83 for κ associated lesions and λ/κ ratio of <0.041 for λ associated lesions. However, the results do not support using this test for first-time urine testing for monoclonal light chains as it is not predictive of positive result, nor does it exclude a monoclonal light chain in urine.
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Affiliation(s)
- Gurmukh Singh
- Department of Pathology, Medical College of Georgia at Augusta University, Augusta, GA, United States
| | - Thomas Cotter
- Department of Pathology, Medical College of Georgia at Augusta University, Augusta, GA, United States
| | - May Ye Mon
- Department of Pathology, Medical College of Georgia at Augusta University, Augusta, GA, United States
| | - Hongyan Xu
- Department of Population Health Sciences, Medical College of Georgia at Augusta University, Augusta, GA, United States
| | - Roni J Bollag
- Department of Pathology, Medical College of Georgia at Augusta University, Augusta, GA, United States
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Fink SL, Wener MH, Rudolf JW, Nwosu A, Tacker DH, Kadkhoda K, Tebo AE, Willrich MAV. A universal reference interval for serum immunoglobulins free light chains may be outdated. Clin Chem Lab Med 2023; 61:e229-e232. [PMID: 37221866 DOI: 10.1515/cclm-2023-0473] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2023] [Accepted: 05/10/2023] [Indexed: 05/25/2023]
Affiliation(s)
- Susan L Fink
- Department of Laboratory Medicine and Pathology, University of Washington, Seattle, WA, USA
| | - Mark H Wener
- Department of Laboratory Medicine and Pathology, University of Washington, Seattle, WA, USA
- Rheumatology Division, Department of Medicine, University of Washington, Seattle, WA, USA
| | - Joseph W Rudolf
- Department of Pathology, University of Utah School of Medicine, Salt Lake City, UT, USA
| | - Ann Nwosu
- Department of Biostatistics, College of American Pathologists, Northfield, IL, USA
| | - Danyel H Tacker
- The Department of Pathology, Anatomy, and Laboratory Medicine, West Virginia University, Morgantown, WV, USA
| | - Kamran Kadkhoda
- Immunopathology Laboratory, Robert Tomsich Pathology and Laboratory Medicine Institute, Cleveland Clinic, Cleveland, OH, USA
| | - Anne E Tebo
- Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN, USA
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6
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Cox MC, Esposito F, Postorino M, Venditti A, Di Napoli A. Serum Paraprotein Is Associated with Adverse Prognostic Factors and Outcome, across Different Subtypes of Mature B-Cell Malignancies-A Systematic Review. Cancers (Basel) 2023; 15:4440. [PMID: 37760410 PMCID: PMC10527377 DOI: 10.3390/cancers15184440] [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: 07/20/2023] [Revised: 08/20/2023] [Accepted: 08/30/2023] [Indexed: 09/29/2023] Open
Abstract
The presence of a serum paraprotein (PP) is usually associated with plasma-cell dyscrasias, Waldenstrom Macroglobulinemia/lymphoplasmacytic lymphoma, and cryoglobulinemia. However, PP is also often reported in other high- and low-grade B-cell malignancies. As these reports are sparse and heterogeneous, an overall view on this topic is lacking, Therefore, we carried out a complete literature review to detail the characteristics, and highlight differences and similarities among lymphoma entities associated with PP. In these settings, IgM and IgG are the prevalent PP subtypes, and their serum concentration is often low or even undetectable without immunofixation. The relevance of paraproteinemia and its prevalence, as well as the impact of IgG vs. IgM PP, seems to differ within B-NHL subtypes and CLL. Nonetheless, paraproteinemia is almost always associated with advanced disease, as well as with immunophenotypic, genetic, and clinical features, impacting prognosis. In fact, PP is reported as an independent prognostic marker of poor outcome. All the above call for implementing clinical practice, with the assessment of paraproteinemia, in patients' work-up. Indeed, more studies are needed to shed light on the biological mechanism causing more aggressive disease. Furthermore, the significance of paraproteinemia, in the era of targeted therapies, should be assessed in prospective trials.
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Affiliation(s)
- Maria Christina Cox
- UOC Malattie Linfoproliferative, Fondazione Policlinico Tor Vergata, 00133 Roma, Italy
| | - Fabiana Esposito
- Ematologia, Dipartimento di Biomedicina e Prevenzione, Università Tor Vergata, 00133 Roma, Italy; (F.E.)
| | - Massimiliano Postorino
- Ematologia, Dipartimento di Biomedicina e Prevenzione, Università Tor Vergata, 00133 Roma, Italy; (F.E.)
| | - Adriano Venditti
- Ematologia, Dipartimento di Biomedicina e Prevenzione, Università Tor Vergata, 00133 Roma, Italy; (F.E.)
| | - Arianna Di Napoli
- Department of Clinical and Molecular Medicine, School of Medicine and Psychology, Sapienza University, 00189 Roma, Italy;
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7
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Singh G, Arinze N, Manthei DM, Plapp FV, Bollag RJ. Urine Protein Immunofixation Electrophoresis: Free Light Chain Urine Immunofixation Electrophoresis Is More Sensitive than Conventional Assays for Detecting Monoclonal Light Chains and Could Serve as a Marker of Minimal Residual Disease. Lab Med 2023; 54:527-533. [PMID: 36857478 DOI: 10.1093/labmed/lmac155] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/03/2023] Open
Abstract
BACKGROUND Immunoglobulin monoclonal light chains (MLCs) in serum and urine are markers for monoclonal gammopathy and could serve as markers of minimal residual disease (MRD) in multiple myeloma (MM). Excretion of MLCs in urine is known to result in renal damage and shorter survival in patients with LC-predominant MM. METHODS Retrospective review of urine immunofixation in 1738 specimens at 3 medical centers was conducted to assess the utility of urinalysis for diagnosis and monitoring of monoclonal gammopathy. We tested 228 stored urine specimens via the modified urine immunofixation method, using antisera to assay free LCs (FLCs). RESULTS Our review of urine immunofixation results and medical records validated the theory that the only meaningful value-added finding was detection of monoclonal free light chains. Examination of 228 urine specimens using our novel method revealed 18.4% additional positive results. The rate of incremental findings for lambda LCs was nearly 3-fold higher than for kappa LCs. CONCLUSIONS The new method of urine immunofixation is significantly more sensitive and more efficient than the conventional method for detecting MLCs in urine. The new assay appears to be sensitive enough to prove that MLCs serve as a marker of MRD in MM.
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Affiliation(s)
- Gurmukh Singh
- Department of Pathology Medical College of Georgia at Augusta University, Augusta, GA
| | - Nkechi Arinze
- Department of Pathology Medical College of Georgia at Augusta University, Augusta, GA
| | | | | | - Roni J Bollag
- Department of Pathology Medical College of Georgia at Augusta University, Augusta, GA
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8
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Azimi V, Slade M, Fiala M, Fortier JM, Stockerl-Goldstein K, Frater JL, Brestoff JR, Jackups R, Zaydman MA. A Single Reference Interval for Interpreting Serum Free Light Chains across Patients with Varying Renal Function. Clin Chem 2023:7153471. [PMID: 37147848 DOI: 10.1093/clinchem/hvad043] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2022] [Accepted: 03/13/2023] [Indexed: 05/07/2023]
Abstract
BACKGROUND Serum free light chain (sFLC) assays are interpreted using a sFLC-ratio-based reference interval (manufacturer's interval) that was defined using a cohort of healthy patients. However, renal impairment elevates the sFLC-ratio, leading to a high false positive rate when using the manufacturer's interval. Prior studies have developed renal-specific reference intervals; however, this approach has not been widely adopted due to practical limitations. Thus, there remains a critical need for a renally robust sFLC interpretation method. METHODS Retrospective data mining was used to define patient cohorts that reflect the spectrum of renal function seen in clinical practice. Two new reference intervals, one based on the sFLC-ratio and one based on a novel principal component analysis (PCA)-based metric, were developed for the FREELITE assay (Binding Site) on the Roche Cobas c501 instrument (Roche). RESULTS Compared to the manufacturer's reference interval, both new methods exhibited significantly lower false positive rates and greater robustness to renal function while maintaining equivalent sensitivity for monoclonal gammopathy (MG) diagnosis. While not significantly different, the point estimate for sensitivity was highest for the PCA-based approach. CONCLUSION Renally robust sFLC interpretation using a single reference interval is possible given a reference cohort that reflects the variation in renal function observed in practice. Further studies are needed to achieve sufficient power and determine if the novel PCA-based metric offers superior sensitivity for MG diagnosis. These new methods offer the practical advantages of not requiring an estimated glomerular filtration rate result or multiple reference intervals, thereby lowering practical barriers to implementation.
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Affiliation(s)
- Vahid Azimi
- Department of Pathology and Immunology, Washington University in St. Louis, School of Medicine, St. Louis, MO, United States
| | - Michael Slade
- Department of Medicine, Division of Oncology, Washington University in St. Louis, School of Medicine, St. Louis, MO, United States
| | - Mark Fiala
- Department of Medicine, Division of Oncology, Washington University in St. Louis, School of Medicine, St. Louis, MO, United States
| | - Julie M Fortier
- Department of Medicine, Division of Oncology, Washington University in St. Louis, School of Medicine, St. Louis, MO, United States
| | - Keith Stockerl-Goldstein
- Department of Medicine, Division of Oncology, Washington University in St. Louis, School of Medicine, St. Louis, MO, United States
| | - John L Frater
- Department of Pathology and Immunology, Washington University in St. Louis, School of Medicine, St. Louis, MO, United States
| | - Jonathan R Brestoff
- Department of Pathology and Immunology, Washington University in St. Louis, School of Medicine, St. Louis, MO, United States
| | - Ronald Jackups
- Department of Pathology and Immunology, Washington University in St. Louis, School of Medicine, St. Louis, MO, United States
| | - Mark A Zaydman
- Department of Pathology and Immunology, Washington University in St. Louis, School of Medicine, St. Louis, MO, United States
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9
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Pearson DS, McEvoy DS, Murali MR, Dighe AS. Use of Clinical Decision Support to Improve the Laboratory Evaluation of Monoclonal Gammopathies. Am J Clin Pathol 2023; 159:192-204. [PMID: 36622340 DOI: 10.1093/ajcp/aqac151] [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: 09/02/2022] [Accepted: 11/03/2022] [Indexed: 01/10/2023] Open
Abstract
OBJECTIVES There is considerable variation in ordering practices for the initial laboratory evaluation of monoclonal gammopathies (MGs) despite clear society guidelines to include serum free light chain (sFLC) testing. We assessed the ability of a clinical decision support (CDS) alert to improve guideline compliance and analyzed its clinical impact. METHODS We designed and deployed a targeted CDS alert to educate and prompt providers to order an sFLC assay when ordering serum protein electrophoresis (SPEP) testing. RESULTS The alert was highly effective at increasing the co-ordering of SPEP and sFLC testing. Preimplementation, 62.8% of all SPEP evaluations included sFLC testing, while nearly 90% of evaluations included an sFLC assay postimplementation. In patients with no prior sFLC testing, analysis of sFLC orders prompted by the alert led to the determination that 28.9% (800/2,769) of these patients had an abnormal κ/λ ratio. In 452 of these patients, the sFLC assay provided the only laboratory evidence of a monoclonal protein. Moreover, within this population, there were numerous instances of new diagnoses of multiple myeloma and other MGs. CONCLUSIONS The CDS alert increased compliance with society guidelines and improved the diagnostic evaluation of patients with suspected MGs.
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Affiliation(s)
- Daniel S Pearson
- Department of Pathology Medicine, Massachusetts General Hospital, Boston, MA, USA
| | | | - Mandakolathur R Murali
- Department of Pathology Medicine, Massachusetts General Hospital, Boston, MA, USA.,Medicine, Massachusetts General Hospital, Boston, MA, USAand
| | - Anand S Dighe
- Department of Pathology Medicine, Massachusetts General Hospital, Boston, MA, USA.,Massachuscetts General Brigham, Somerville, MA, USA
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10
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Singh G, Whitaker BM, Wu AHB, Xu H, Bollag RJ. Serum Free Light Chain Quantification Testing: Comparison of Two Methods for Disease Monitoring. J Appl Lab Med 2022; 7:1290-1301. [DOI: 10.1093/jalm/jfac068] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2022] [Accepted: 07/01/2022] [Indexed: 11/13/2022]
Abstract
Abstract
Background
Levels of free immunoglobulin light chains in serum and urine are a sensitive measure of dysregulated immunoglobulin synthesis. The development of an assay for free light chains in serum was a major advance in laboratory testing for monoclonal gammopathies. The original assay by The Binding Site, called Freelite®, has been in common use in laboratory monitoring of monoclonal gammopathies. Two clinical entities, myeloma-defining condition and light chain-predominant multiple myeloma, rely on quantitative measurements of serum free light chains.
Methods
Using polyclonal antisera specific to free light chains, Diazyme Laboratories developed a latex immunoturbidimetric assay for quantification of human kappa and lambda serum free light chains. We evaluated the Diazyme assay by comparing the results of kappa and lambda free light chain quantification, and kappa/lambda ratio with the results on the same specimens by the Freelite method. We also compared the correlation of the 2 methods to evaluate response to treatment and to changes in clinical status of patients with multiple myeloma.
Results
The results of Freelite and Diazyme methods are comparable. There was no statistically significant difference in the performance of the 2 assays for quantification of light chains, kappa/lambda ratio, or correlation of clinical parameters from patients with multiple myeloma at various stages of monitoring the disease in 2 geographically diverse laboratory and clinical environments.
Conclusions
The Diazyme method is comparable to Freelite and provides an opportunity to add the test to front-end automation and improvement in efficiency of the assay.
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Affiliation(s)
- Gurmukh Singh
- Department of Pathology, Medical College of Georgia at Augusta University , Augusta, GA 30912 , USA
| | - Brooke M Whitaker
- Department of Pathology, Medical College of Georgia at Augusta University , Augusta, GA 30912 , USA
| | - Alan H B Wu
- Department of Laboratory Medicine, University of California at San Francisco, 1001 Potrero Ave., SFGH 5 , San Francisco CA 94110 , USA
| | - Hongyan Xu
- Department of Population Health Sciences, Medical College of Georgia at Augusta University , Augusta, GA 30912 , USA
| | - Roni J Bollag
- Department of Pathology, Medical College of Georgia at Augusta University , Augusta, GA 30912 , USA
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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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Gill SS, Fellin E, Stampke L, Zhao Y, Masri A. Clinical Clues and Diagnostic Workup of Cardiac Amyloidosis. Methodist Debakey Cardiovasc J 2022; 18:36-46. [PMID: 35414856 PMCID: PMC8932349 DOI: 10.14797/mdcvj.1061] [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: 11/12/2021] [Accepted: 02/10/2022] [Indexed: 11/18/2022] Open
Abstract
Cardiac amyloidosis is increasingly recognized as an underlying cause of left ventricular wall thickening, heart failure, and arrhythmia with variable clinical presentation. Due to the subtle cardiac findings in early transthyretin cardiac amyloidosis and the availability of therapies that can modify but not reverse the disease progression, early recognition is vital. In light chain amyloidosis, timely diagnosis and treatment can significantly improve survival. In this manuscript, we review the clinical, imaging, and electrocardiographic clues that should raise suspicion for cardiac amyloidosis and provide a simplified diagnostic workup algorithm that ensures an accurate diagnosis. The evolution of the noninvasive diagnosis of cardiac amyloidosis has significantly influenced our understanding of disease prevalence, presentations, and outcomes. However, clinical recognition of clues and red flags remains the most important factor in advancing the care of patients with cardiac amyloidosis.
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Affiliation(s)
- Sajan S. Gill
- Knight Cardiovascular Institute, Oregon Health & Science University School of Medicine, Portland, Oregon, US
| | - Eric Fellin
- Oregon Health & Science University School of Medicine, Portland, Oregon, US
| | - Lisa Stampke
- Oregon Health & Science University School of Medicine, Portland, Oregon, US
| | - Yunazi Zhao
- Knight Cardiovascular Institute, Oregon Health & Science University School of Medicine, Portland, Oregon, US
| | - Ahmad Masri
- Knight Cardiovascular Institute, Oregon Health & Science University School of Medicine, Portland, Oregon, US
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13
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Jin Y, Savage NM, Bollag RJ, Xu H, Singh G. Light Chain Multiple Myeloma: High Serum Free Light Chain Concentrations Portend Renal Damage and Poorer Survival. J Appl Lab Med 2021; 6:1592-1600. [PMID: 34468749 DOI: 10.1093/jalm/jfab090] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2021] [Accepted: 06/25/2021] [Indexed: 12/11/2022]
Abstract
BACKGROUND Monoclonal immunoglobulins provide an indication of the tumor burden in patients with plasma cell neoplasms. Higher concentrations of serum free light chains in light chain predominant multiple myeloma have been shown to correlate with a poorer outcome. We examined the correlations of serum free light chain concentrations in light chain myelomas with survival, estimated glomerular filtration rate (eGFR) and other clinical and pathological parameters. METHODS Records of patients with light chain multiple myelomas were reviewed. Highest concentration of serum free light chains for each patient were plotted to ascertain an inflection/change point. Survival, eGFR, and other clinical and pathological parameters were compared between the low and high light chain concentration groups. RESULTS Plotting serum free light chain concentrations revealed an inflection point at a concentration of 455 mg/L apportioning patients in to 2 subgroups: 39 patients with low light chain concentrations and 26 patients with high concentrations. The high concentration group had more unfavorable pathology in bone marrow examination in terms of higher neoplastic plasma cell burden and high-risk cytogenetics. The survival rate and eGFR in the high concentration group were significantly worse than in the low concentration group. CONCLUSIONS As noted for light chain predominant multiple myeloma, high serum free light chain concentration in light chain multiple myelomas are associated with higher renal disease burden and shorter survival. Monitoring of serum free light chain concentrations and customizing treatments to address this parameter are warranted.
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Affiliation(s)
- Yulan Jin
- Department of Pathology, Augusta University
| | | | - Roni J Bollag
- Department of Pathology, Medical College of Georgia at Augusta University
| | - Hongyan Xu
- Department of Biostatistics and Data Sciences, Augusta University
| | - Gurmukh Singh
- Department of Clinical Pathology, Truman Medical Center
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14
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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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15
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Singh G, Savage NM, Jillella AP, Bollag RJ. Light Chain-Predominant Multiple Myeloma Subgroup: Impaired Renal Function Correlates with Decreased Survival. Lab Med 2021; 53:145-148. [PMID: 34388245 DOI: 10.1093/labmed/lmab054] [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] [Indexed: 12/12/2022] Open
Abstract
OBJECTIVE Patients with light chain-predominant multiple myeloma have been shown to exhibit shorter survival. Retrospective comparison of clinical and laboratory data was undertaken to ascertain the likely cause(s) of this observation. METHODS Records of patients with multiple myeloma seen at 1 institution revealed 316 patients with conventional and 71 patients with light chain-predominant multiple myelomas with secretion of intact immunoglobulins. Laboratory and clinical findings in the 2 groups were compared. RESULTS Patients with light chain-predominant multiple myeloma had a significantly higher death rate, a higher rate of chronic dialysis, a lower estimated glomerular filtration rate and serum albumin, a significantly higher urine protein concentration, and a significantly higher prevalence of hypertension and blood transfusion requirements. Other clinical and laboratory parameters surveyed were not significantly different between the 2 groups. CONCLUSION The shorter survival of patients with light chain-predominant multiple myeloma is clearly associated with renal damage caused by excess free immunoglobulin light chains. Renal damage may be ameliorated by early aggressive treatment with chemotherapy, plasmapheresis, and dialysis; a multi-institutional prospective controlled trial would be needed to test this hypothesis.
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Affiliation(s)
- Gurmukh Singh
- Division of Clinical Pathology, Department of Pathology, Medical College of Georgia at Augusta University, Augusta, Georgia, US
| | - Natasha M Savage
- Division of Clinical Pathology, Department of Pathology, Medical College of Georgia at Augusta University, Augusta, Georgia, US
| | - Anand P Jillella
- Division of Hematology/Oncology, Department of Medicine, Medical College of Georgia at Augusta University, Augusta, Georgia, US
| | - Roni J Bollag
- Division of Clinical Pathology, Department of Pathology, Medical College of Georgia at Augusta University, Augusta, Georgia, US
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16
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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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17
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Daves M, Piccin A, Roccaforte V, Lippi G. Comparison of Freelite and N-Latex serum free light chain assays: a critical review. Biochem Med (Zagreb) 2021; 31:030701. [PMID: 34393594 PMCID: PMC8340501 DOI: 10.11613/bm.2021.030701] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2021] [Accepted: 06/12/2021] [Indexed: 11/07/2022] Open
Abstract
Introduction The measurement of serum free light chain (FLC) represents a fundamental aspect on the assessment of patients with monoclonal gammopathies (MG). Different analytical methods for FLC have become available with the possibility to obtain different value with a substantial impact on the assessment of patients with MG. This study aimed to evaluate FLC results obtained with two different assays and how the difference value obtained can impact in the patient’s assessment. Materials and methods Ninety-three patient serum samples that underwent analysis for FLC with two different methods, Serum Freelite (The Binding Site, Birmingham, UK) and N-Latex FLC (Siemens, Marburg, Germany), were included in this retrospective study. Statistical analysis was performed to evaluate correlation, difference, and the grade of concordance between the results obtained with the two methods. Results Significant statistical differences between the results obtained from the two methods were found (P < 0.05). A good correlation was found (0.99 for κ FLC, 0.95 for λ FLC, and 0.94 for the κ/λ ratio, respectively). We found a weighted kappa value of 0.65 for κ/λ ratio, 0.65 for λ FLC and 0.90 for κ FLC. A positive bias found with the Bland-Altman plot mirrors overestimation of κ FLC and κ/λ ratio with Freelite compared to N-Latex, whilst a negative bias underscores underestimation of λ FLC by Freelite compared to N-Latex. Conclusion Although in general the concordance between Freelite and N-Latex appears satisfactory, several discrepancies could be evidenced and consequently the two assays are not interchangeable.
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Affiliation(s)
- Massimo Daves
- Clinical Biochemical Laboratory, Hospital of Bolzano, Bolzano, Italy
| | - Andrea Piccin
- Northern Ireland Blood Transfusion Service (NIBTS), Belfast, United Kingdom.,Department of Internal Medicine V, University of Innsbruck, Innsbruck, Austria
| | | | - Giuseppe Lippi
- Section of Clinical Biochemistry, Verona University of Verona, Verona, Italy
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18
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Singh G, Bollag R. Quantification by Ultrafiltration and Immunofixation Electrophoresis Testing for Monoclonal Serum Free Light Chains. Lab Med 2021; 51:592-600. [PMID: 32285117 DOI: 10.1093/labmed/lmaa012] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
OBJECTIVE Measurement of monoclonal immunoglobulins is a reliable estimate of the plasma cell tumor mass. About 15% of plasma cell myelomas secrete light chains only. The concentration of serum free light chains is insufficient evidence of the monoclonal light chain burden. A sensitive quantitative estimate of serum free monoclonal light chains could be useful for monitoring patients with light chain myeloma. We describe such an assay that does not require mass-spectrometry equipment or expertise. METHODS Serum specimens from patients with known light chain myelomas and controls were subjected to ultrafiltration through a membrane with pore size of 50 kDa. The filtrate was concentrated and tested by immunofixation electrophoresis. The relative area under the monoclonal peak, compared to that of the total involved light chain composition, was estimated by densitometric scanning of immunofixation gels. The proportion of the area occupied by the monoclonal peak in representative densitometric scans was used to arrive at the total serum concentration of the monoclonal serum free light chains. RESULTS Using an ultracentrifugation and concentration process, monoclonal serum free light chains were detectable, along with polyclonal light chains, in all 10 patients with active light chain myelomas. Monoclonal light chains were identified in serum specimens that did not reveal monoclonal light chains by conventional immunofixation electrophoresis. The limit of detection by this method was 1.0 mg/L of monoclonal serum free light chains. CONCLUSION The method described here is simple enough to be implemented in academic medical center clinical laboratories and does not require special reagents, equipment, or expertise. Even though urine examination is the preferred method for the diagnosis of light chain plasma cell myelomas, measurement of the concentration of serum free light chains provides a convenient, albeit inadequate, way to monitor the course of disease. The method described here allows effective electrophoretic differentiation of monoclonal serum free light chain from polyclonal serum free light chains and provides a quantitation of the monoclonal serum free light chains in monitoring light chain monoclonal gammopathies.
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Affiliation(s)
- Gurmukh Singh
- Department of Pathology Medical College of Georgia at Augusta University, Augusta, GA
| | - Roni Bollag
- Department of Pathology Medical College of Georgia at Augusta University, Augusta, GA
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19
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Zamani F, Shokripour M, Mokhtari M. Evaluation of Correlation between Serum Free Light-Chain Assay and Bone Marrow Study in Multiple Myeloma Patients. Int J Hematol Oncol Stem Cell Res 2021; 15:152-159. [PMID: 35082996 PMCID: PMC8748244 DOI: 10.18502/ijhoscr.v15i3.6845] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2020] [Accepted: 04/21/2020] [Indexed: 11/24/2022] Open
Abstract
Background: Multiple myeloma is a hematologic malignancy manifested by the secretion of abnormal immunoglobulin. Different methods have been described for diagnosis and patient response to management. Serum free light-chain assay is recently approved in the diagnosis of multiple myeloma patients. This study aimed to evaluate the diagnostic accuracy of serum free light-chain assay and its agreement to bone marrow findings. Materials and Methods: Forty-six patients with the diagnosis of multiple myeloma were enrolled in the study. The patients were grouped into newly diagnosed cases (22 patients,47.8%) and known cases who were under treatment (24 patients,52.2%). Bone marrow study was done and percentage and clonal status of plasma cells were evaluated by a combination of immunohistochemistry and flow cytometry. Free light-chain assay was done in all patients and sensitivity, specificity, positive predictive value, and negative predictive value were analyzed. Results: Thirty of 46 patients showed monoclonal plasma cell infiltration and 16 patients showed polyclonal plasma cell infiltration based on bone marrow findings. An abnormal κ/λ ratio was seen in 15(68.18%) of new cases and 16(66.6%) of known cases. Sensitivity, specificity, PPV and NPV for κ⁄λ ratio were 72.73%, 46.15%, 71%, and 50%, respectively. Conclusion: In conclusion, due to high false positive and false negative results, the presence of an abnormal serum FLC ratio was not equal to the presence of monoclonal gammopathy, and observation of a normal ratio does not exclude the presence of monoclonal gammopathy.
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Affiliation(s)
- Fatemeh Zamani
- Department of Pathology, Shahid Faghihi Hospital, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Mansoureh Shokripour
- Department of Pathology, Shahid Faghihi Hospital, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Maral Mokhtari
- Department of Pathology, Shahid Faghihi Hospital, Shiraz University of Medical Sciences, Shiraz, Iran
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20
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Ullah A, Omar N, Savage NM, Bollag RJ, Singh G. Immune subtraction for improved resolution in serum protein immunofixation electrophoresis and antibody isotype determination in a patient with autoantibody. Pract Lab Med 2021; 26:e00240. [PMID: 34124325 PMCID: PMC8173025 DOI: 10.1016/j.plabm.2021.e00240] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2020] [Revised: 04/18/2021] [Accepted: 05/26/2021] [Indexed: 11/21/2022] Open
Abstract
Heavy chain isotypes of low level monoclonal immunoglobulins are sometimes obscured in serum immunofixation electrophoresis (SIFE) by a heavy background of polyclonal immunoglobulins. However, accurate determination of the heavy chain isotype is essential for a complete diagnosis, as isotype determination of autoantibodies may have relevance in determining therapeutic procedures. Immune subtraction (IS) was employed in a patient with neuropathy and GD1a autoantibody. IS allowed identification of the cognate heavy chain related to a lambda light chain restriction noted on initial SIFE as well as isotype determination of the autoantibody. Antisera specific to individual heavy and light chains were used for depletion of specific immunoglobulin types. Depletion of kappa light chain associated immunoglobulins allowed unequivocal determination of the isotype of lambda light chain-associated low level monoclonal band to be IgG Lambda. Selective depletion of kappa, lambda, gamma and mu heavy chain immunoglobulins was employed to determine IgG Kappa isotype of the auto-antibody.
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Affiliation(s)
- Asad Ullah
- Department of Pathology, Medical College of Georgia at Augusta University, Augusta, GA, 30912, USA
| | - Nivin Omar
- Department of Pathology, Medical College of Georgia at Augusta University, Augusta, GA, 30912, USA
| | - Natasha M Savage
- Department of Pathology, Medical College of Georgia at Augusta University, Augusta, GA, 30912, USA
| | - Roni J Bollag
- Department of Pathology, Medical College of Georgia at Augusta University, Augusta, GA, 30912, USA
| | - Gurmukh Singh
- Department of Pathology, Medical College of Georgia at Augusta University, Augusta, GA, 30912, USA
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21
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Emergence of Oligoclonal Bands in Association with the use of Chemotherapy and Hematopoietic Stem Cell Transplantation. Indian J Clin Biochem 2021; 37:328-334. [DOI: 10.1007/s12291-021-00983-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2020] [Accepted: 05/08/2021] [Indexed: 10/21/2022]
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22
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Rindlisbacher B, Schild C, Egger F, Bacher VU, Pabst T, Leichtle A, Andres M, Sédille-Mostafaie N. Serum Free Light Chain Assay: Shift Toward a Higher κ/λ Ratio. J Appl Lab Med 2021; 5:114-125. [PMID: 32445339 DOI: 10.1093/jalm.2019.029330] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2019] [Accepted: 07/10/2019] [Indexed: 12/13/2022]
Abstract
BACKGROUND The analysis of serum free light chains (FLCs) is clinically relevant for the diagnosis and therapeutic management of clonal plasma cell disorders. This study compares the performance of monoclonal and polyclonal FLC κ and λ assays in clinical samples determined in a single academic center. METHODS Serum FLCs were analyzed from 102 patients using the Freelite (Binding Site) and N Latex (Siemens) assays on the BN ProSpec System (Siemens). When available, data for protein electrophoresis, immunofixation, C-reactive protein, and estimated glomerular filtration rate (eGFR) were combined with FLC results to evaluate performance. RESULTS Method evaluation showed acceptable imprecision and inaccuracy measures of <4.4% and 12.9%, respectively. Poor agreement between the methods was observed, including constant and proportional bias and poor correlation (Kendall τ, 0.671-0.901). The N Latex assay was not affected by the renal impairment estimated by eGFR, unlike the FLC κ/λ ratio results by the Freelite assay. With the Freelite assay, 98% of putative controls without monoclonal gammopathy (n = 42) showed a κ/λ ratio that was above the median of the standard diagnostic range or renal diagnostic range. A shift toward higher κ/λ ratios was also observed when retrospective data between 2011 and 2017 were compared. CONCLUSIONS Unlike the Freelite assay, κ/λ ratios analyzed with the N Latex assay were not affected by renal failure. Both methods showed acceptable performances using nephelometry, but they were poorly correlated. A shift toward κ/λ ratios might impair the specificity of borderline increased κ/λ results. This should be considered when interpreting FLC κ and λ results.
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Affiliation(s)
- Barbara Rindlisbacher
- University Institute of Clinical Chemistry, Bern University Hospital, and University of Bern, Bern, Switzerland.,Center of Laboratory Medicine, Switzerland
| | - Christof Schild
- University Institute of Clinical Chemistry, Bern University Hospital, and University of Bern, Bern, Switzerland.,Center of Laboratory Medicine, Switzerland
| | | | - Vera U Bacher
- Center of Laboratory Medicine, Switzerland.,Department of Hematology and Central Hematology Laboratory, Switzerland
| | - Thomas Pabst
- Department of Medical Oncology, Bern University Hospital, and University of Bern, Switzerland
| | - Alexander Leichtle
- University Institute of Clinical Chemistry, Bern University Hospital, and University of Bern, Bern, Switzerland
| | - Martin Andres
- Department of Hematology and Central Hematology Laboratory, Switzerland
| | - Nazanin Sédille-Mostafaie
- University Institute of Clinical Chemistry, Bern University Hospital, and University of Bern, Bern, Switzerland.,Center of Laboratory Medicine, Switzerland
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23
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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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24
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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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25
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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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Jain A, Prasad P, Chaudhry S, Gupta DK, Saluja S. Response of multifocal acquired demyelinating sensorimotor neuropathy associated with atypical chronic lymphocytic leukemia to rituximab therapy. Blood Res 2020; 55:117-120. [PMID: 32429623 PMCID: PMC7343549 DOI: 10.5045/br.2020.2020047] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2020] [Revised: 04/20/2020] [Accepted: 05/11/2020] [Indexed: 11/17/2022] Open
Affiliation(s)
- Ankur Jain
- Department of Haematology, Vardhman Mahavir Medical College and Safdarjung Hospital, New Delhi, India
| | - Pooja Prasad
- Department of Haematology, Vardhman Mahavir Medical College and Safdarjung Hospital, New Delhi, India
| | - Sumita Chaudhry
- Department of Haematology, Vardhman Mahavir Medical College and Safdarjung Hospital, New Delhi, India
| | - Dipendra Kumar Gupta
- Department of Haematology, Vardhman Mahavir Medical College and Safdarjung Hospital, New Delhi, India
| | - Sumita Saluja
- Department of Haematology, Vardhman Mahavir Medical College and Safdarjung Hospital, New Delhi, India
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Campbell L, Simpson D, Shields A, Ferry B, Ramasamy K, Sadler R. In-house age-specific reference ranges for free light chains measured on the SPAPlus® analyser. Ann Clin Biochem 2020; 57:138-143. [DOI: 10.1177/0004563219899421] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Background The measurement of monoclonal free light chains is being increasingly utilized since the introduction of serum-based assays. It is important for laboratories to determine their own reference ranges in order to reflect the local population. The aim of this study was to determine if age-adjusted reference ranges for serum free light chains would have implications for demand management of further laboratory investigations including immunofixation. Methods After certain exclusions, 4293 samples from individuals seen in primary care across Oxfordshire between 2014 and 2016 were identified for analysis of patient characteristics, serum free light chain results and estimated glomerular filtration rate. Results We found age to be an independent variable when considering serum free light chain concentrations, ratio and estimated glomerular filtration rate. The reference ranges derived from our data differ markedly from the original Binding Site ranges. When the age-specific ranges are retrospectively applied to our population, there is a 38% decrease in follow-up testing with no loss of specificity. Conclusion We feel confident implementing new age-specific serum free light chain reference ranges in our laboratory. We have developed a simple algorithm for evaluating serum free light chains based on age and estimated glomerular filtration rate. We encourage laboratories to establish their own local reference ranges using large cohorts and their chosen serum free light chain assay platform.
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Affiliation(s)
- Lauren Campbell
- Oxford University Hospitals NHS Foundation Trust, Oxford, UK
| | - Dawn Simpson
- Oxford University Hospitals NHS Foundation Trust, Oxford, UK
| | - Adrian Shields
- University Hospitals Birmingham NHS Foundation Trust, Birmingham, UK
| | - Berne Ferry
- National School of Healthcare Science, Birmingham, UK
| | | | - Ross Sadler
- Oxford University Hospitals NHS Foundation Trust, Oxford, UK
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Lee WS, Singh G. Serum Free Light Chain Assay in Monoclonal Gammopathic Manifestations. Lab Med 2019; 50:381-389. [DOI: 10.1093/labmed/lmz007] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Abstract
Background
Serum free light chain assay is used in the diagnosis and monitoring of monoclonal gammopathic manifestations. For the kappa (κ)/lambda (λ) ratio, there is a 36% false-positive rate in patients without monoclonal gammopathic manifestations and a 30% false-negative rate in patients with monoclonal gammopathic manifestations. This study was undertaken to address the higher false-negative rate in λ chain–associated monoclonal lesions.
Methods
Results of serum protein electrophoresis, serum immunofixation electrophoresis, and serum free light chain assays were reviewed retrospectively. The results for serum free light chains in cases of intact immunoglobulin monoclonal gammopathic manifestations only were analyzed.
Results
Concentrations of involved serum free light chains were significantly higher in κ chain–associated lesions than in λ chain–associated lesions. The concentration of uninvolved light chains was significantly higher in λ chain–associated lesions.
Conclusions
κ light chains are present in significantly greater abundance than are λ chains in their respective monoclonal lesions. Moreover, κ and λ light-chain levels are not comparable for similar quantitative levels of monoclonal immunoglobulins. The findings warrant a reconsideration of the role of serum free light chain concentrations and involved to uninvolved serum free light chain ratio in designation of myeloma-defining conditions and other diagnostic criteria based on serum free light chain assay.
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Affiliation(s)
- Won S Lee
- Department of Pathology, Medical College of Georgia at Augusta University, Augusta, GA
| | - Gurmukh Singh
- Department of Pathology, Medical College of Georgia at Augusta University, Augusta, GA
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Singh G. Concentrations of Serum Free Light Chains in Kappa and Lambda Lesions in Light-Chain Myelomas. Lab Med 2018; 50:189-193. [DOI: 10.1093/labmed/lmy067] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Affiliation(s)
- Gurmukh Singh
- Department of Pathology, Medical College of Georgia at Augusta University, Augusta, Georgia
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Lee WS, Singh G. Serum Free Light Chains in Neoplastic Monoclonal Gammopathies: Relative Under-Detection of Lambda Dominant Kappa/Lambda Ratio, and Underproduction of Free Lambda Light Chains, as Compared to Kappa Light Chains, in Patients With Neoplastic Monoclonal Gammopathies. J Clin Med Res 2018; 10:562-569. [PMID: 29904440 PMCID: PMC5997416 DOI: 10.14740/jocmr3383w] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2018] [Accepted: 03/02/2018] [Indexed: 12/15/2022] Open
Abstract
Background Quantitative evaluation of serum free light chains is recommended for the work up of monoclonal gammopathies. Immunoglobulin light chains are generally produced in excess of heavy chains. In patients with monoclonal gammopathy, κ/λ ratio is abnormal less frequently with lambda chain lesions. This study was undertaken to ascertain if the levels of overproduction of the two light chain types and their detection rates are different in patients with neoplastic monoclonal gammopathies. Methods Results of serum protein electrophoresis (SPEP), serum protein immunofixation electrophoresis (SIFE), urine protein electrophoresis (UPEP), urine protein immunofixation electrophoresis (UIFE), and serum free light chain assay (SFLCA) in patients with monoclonal gammopathies were examined retrospectively. Results The κ/λ ratios were appropriately abnormal more often in kappa chain lesions. Ratios of κ/λ were normal in about 25% of patients with lambda chain lesions in whom free homogenous lambda light chains were detectable in urine. An illustrative case suggests underproduction of free lambda light chains, in some instances. Conclusions The lower prevalence of lambda dominant κ/λ ratio in lesions with lambda light chains is estimated to be due to relative under-detection of lambda dominant κ/λ ratio in about 25% of the patients and because lambda chains are not produced in as much excess of heavy chains as are kappa chains, in about 5% of the patients. The results question the medical necessity and clinical usefulness of the serum free light chain assay. UPEP/UIFE is under-utilized.
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Affiliation(s)
- Won Sok Lee
- Medical College of Georgia at Augusta University, Augusta, GA 30912, USA
| | - Gurmukh Singh
- Medical College of Georgia at Augusta University, Augusta, GA 30912, USA
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de Macêdo SRB, de Lima LAR, de Torres SM, de Oliveira VVG, de Morais RN, Peixoto CA, Tenorio BM, Junior VADS. Effects of intratesticular injection of zinc-based solution in rats in combination with anti-inflammatory and analgesic drugs during chemical sterilization. Vet World 2018; 11:649-656. [PMID: 29915504 PMCID: PMC5993773 DOI: 10.14202/vetworld.2018.649-656] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2018] [Accepted: 04/16/2018] [Indexed: 02/02/2023] Open
Abstract
Aim Chemical sterilization is a non-surgical method of contraception based on compounds injected into the testis to induce infertility. However, these injections can cause discomfort and pain able to impair the recovery of animals after this treatment. The objective of this study was to investigate if anti-inflammatories or pain relievers inhibited the sterilizing effect of zinc gluconate-based solution on the testis. Materials and Methods Adult rats were treated in groups: G1 (control), G2 (dimethyl sulfoxide + dipyrone); G3 (dipyrone/zinc); G4 (dipyrone + celecoxib/zinc); G5 (dipyrone + meloxicam/zinc), and G6 (dipyrone + dexamethasone/zinc) in a single dose per day during 7 days. Animals were analyzed at 7, 15, and 30 days after treatments. Results The zinc-induced a widespread testicular degeneration and decreased testosterone levels even in combination with anti-inflammatories or pain relievers. Testis, epididymis, prostate, and seminal vesicle had a weight reduction. The anti-inflammatory effect of dexamethasone interfered in the desired action of zinc gluconate in the 1st 15 days and celecoxib up to 7 days. Conclusion Meloxicam plus dipyrone did not impair the chemical sterilization based on zinc gluconate, and it can be used to reduce nociceptive effects in animals after chemical sterilization.
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Affiliation(s)
| | | | - Sandra Maria de Torres
- Department of Veterinary Medicine, Federal Rural University of Pernambuco, Recife, Brazil
| | | | | | - Christina Alves Peixoto
- Laboratory of Ultrastructure, Aggeu Magalhães Research Center (CPqAM), Recife, Pernambuco, Brazil
| | - Bruno Mendes Tenorio
- Department of Morphology, Federal University of Paraíba, João Pessoa, Paraíba, Brazil
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Xu B, Tang Y, Zhou J, Zhang P, Li H. Disease spectrum of abnormal serum free light chain ratio and its diagnostic significance. Oncotarget 2017; 8:82268-82279. [PMID: 29137262 PMCID: PMC5669888 DOI: 10.18632/oncotarget.19391] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2017] [Accepted: 06/11/2017] [Indexed: 01/22/2023] Open
Abstract
OBJECTIVE To analyze the spectrum of abnormal serum free light chain ratio (sFLC κ/λ ratio), and to redefine the range of sFLC κ/λ ratio, so as to achieve hierarchical diagnosis of diseases with abnormal sFLC κ/λ ratio, resulting in the increased sensitivity and specificity in the diagnosis of monoclonal plasma diseases. METHODS Enrolled 1,340 patients with abnormal sFLC κ/λ ratio (<0.26 or >1.65) were grouped: (1) group A: malignant plasma diseases; (2) group B: monoclonal gammopathies of undetermined significance (MGUS); (3) group C: reactive plasma diseases. These patients were further divided by renal function eGFR <60 or >60 ml/min/1.73m2 to eliminate renal diseases influencing the results. Statistical analyses was performed by using SPSS 22 software. RESULTS When sFLC κ/λ ratio >3.49 and eGFR >60ml/min/1.73m2, the sensitivity and specificity of the diagnosis of malignant plasma diseases were 86.1% and 94.0%, respectively. When sFLC κ/λ ratio >2.89 and eGFR <60ml/min/1.73m2, the sensitivity and specificity of the diagnosis of malignant plasma diseases were 92.0% and 97.0%, respectively. CONCLUSION The sensitivity and specificity of the diagnosis of monoclonal plasma diseases can be significantly improved by redefining the cut-off value of sFLC κ/λ ratio and the renal function index of eGFR.
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Affiliation(s)
- Bin Xu
- Department of Hematology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Yi Tang
- Department of Hematology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Jianfeng Zhou
- Department of Hematology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Peiling Zhang
- Department of Hematology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Huijun Li
- Department of Clinical Laboratory, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China
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Vyas SG, Singh G. Prospective Identification of Oligoclonal/Abnormal Band of the Same Immunoglobulin Type as the Malignant Clone by Differential Location of M-Spike and Oligoclonal Band. J Clin Med Res 2017; 9:826-830. [PMID: 28912918 PMCID: PMC5593429 DOI: 10.14740/jocmr3109w] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2017] [Accepted: 06/29/2017] [Indexed: 01/16/2023] Open
Abstract
Background Serum and urine protein electrophoreses and immunofixation electrophoreses are the gold standards in diagnosing monoclonal gammopathy. Identification of oligoclonal bands in post-treatment patients has emerged as an important issue and recording the location of the malignant monoclonal peak may facilitate prospective identification of a new “monoclonal” spike as being distinct from the malignant peak. Methods We recorded the locations of monoclonal spikes in descriptive terms, such as being in the cathodal region, mid-gamma region, anodal region, and beta region. The location of monoclonal or restricted heterogeneity bands in subsequent protein electrophoreses was compared to the location of the original malignant spike. Results In a patient with plasma cell myeloma, the original monoclonal IgG kappa band was located at the anodal end of gamma region. Post-treatment, an IgG kappa band was noted in mid-gamma region and the primary malignant clone was not detectable by serum protein immunofixation electrophoresis (SIFE) in post-treatment sample. Even though the κ/λ ratio remained abnormal, we were able to recognize stringent complete response by noting the different location of the new IgG kappa band as a benign regenerative process. Conclusions Recording the location of the malignant monoclonal spike facilitates the identification of post-treatment oligoclonal bands, prospectively. Recognizing the regenerative, benign, bands in post-transplant patients facilitates the determination of stringent complete response despite an abnormal κ/λ ratio.
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Affiliation(s)
- Shikhar G Vyas
- 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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Singh G. Oligoclonal Pattern/Abnormal Protein Bands in Post-Treatment Plasma Cell Myeloma Patients: Implications for Protein Electrophoresis and Serum Free Light Chain Assay Results. J Clin Med Res 2017; 9:671-679. [PMID: 28725315 PMCID: PMC5505303 DOI: 10.14740/jocmr3049w] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2017] [Accepted: 05/02/2017] [Indexed: 12/18/2022] Open
Abstract
BACKGROUND The impact of autologous stem cell transplantation (ASCT) in plasma cell myeloma patients on the frequency, quality, and timing of oligoclonal pattern in serum protein electrophoresis/immunofixation electrophoresis (SPEP/SIFE) and serum free light chain assay (SFLCA) was evaluated. METHODS Laboratory results and clinical data for 251 patients with plasma cell myeloma, who had SPEP/SIFE and/or SFLCA performed between January 2010 and December 2016 were reviewed. The results for SPEP/SIFE and SFLCA were compared in patients with ASCT to those without ASCT. The implications of oligoclonal pattern in interpretation of SPEP/SIFE and SFLCA - κ/λ ratio were addressed. RESULTS In 251 patients, a total of 3,134 observations, of either SPEP/SIFE and/or SFLCA, were reviewed. One hundred fifty-nine patients received ASCT. The incidence of oligoclonal patterns was significantly higher after ASCT. More than half of the oligoclonal patterns developed in the first year after transplantation. In 13 of the 84 patients with lambda chain restricted plasma cell myeloma, the κ/λ ratio was kappa dominant in the presence of oligoclonal pattern. There was no reversal of κ/λ ratio in patients with kappa chain restricted plasma cell myelomas. CONCLUSIONS ASCT is associated with significantly higher incidence of oligoclonal patterns than with chemotherapy alone. The presence of oligoclonal patterns has the potential to interfere with the interpretation of SPEP/SIFE and ascertainment of complete remission. At a minimum, the oligoclonal pattern caused an incorrect kappa dominant κ/λ ratio in 15.5% of patients with lambda chain restricted plasma cell myeloma. If a similar rate were to be applied to the 167 kappa chain myeloma patients, about 26 of these would have displayed an erroneous kappa chain dominant κ/λ ratio. The presence of oligoclonal pattern further degrades the performance of already dubious SFLCA. The need for recording the location of monoclonal spike in SPEP/SIFE and higher resolution protein electrophoresis methods are highlighted.
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Affiliation(s)
- 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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Qasaimeh MA, Wu YC, Bose S, Menachery A, Talluri S, Gonzalez G, Fulciniti M, Karp JM, Prabhala RH, Karnik R. Isolation of Circulating Plasma Cells in Multiple Myeloma Using CD138 Antibody-Based Capture in a Microfluidic Device. Sci Rep 2017; 7:45681. [PMID: 28374831 PMCID: PMC5379479 DOI: 10.1038/srep45681] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2016] [Accepted: 03/02/2017] [Indexed: 12/15/2022] Open
Abstract
The necessity for bone marrow aspiration and the lack of highly sensitive assays to detect residual disease present challenges for effective management of multiple myeloma (MM), a plasma cell cancer. We show that a microfluidic cell capture based on CD138 antigen, which is highly expressed on plasma cells, permits quantitation of rare circulating plasma cells (CPCs) in blood and subsequent fluorescence-based assays. The microfluidic device is based on a herringbone channel design, and exhibits an estimated cell capture efficiency of ~40–70%, permitting detection of <10 CPCs/mL using 1-mL sample volumes, which is difficult using existing techniques. In bone marrow samples, the microfluidic-based plasma cell counts exhibited excellent correlation with flow cytometry analysis. In peripheral blood samples, the device detected a baseline of 2–5 CD138+ cells/mL in healthy donor blood, with significantly higher numbers in blood samples of MM patients in remission (20–24 CD138+ cells/mL), and yet higher numbers in MM patients exhibiting disease (45–184 CD138+ cells/mL). Analysis of CPCs isolated using the device was consistent with serum immunoglobulin assays that are commonly used in MM diagnostics. These results indicate the potential of CD138-based microfluidic CPC capture as a useful ‘liquid biopsy’ that may complement or partially replace bone marrow aspiration.
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Affiliation(s)
- Mohammad A Qasaimeh
- Division of Engineering, New York University Abu Dhabi, Abu Dhabi, UAE.,Mechanical and Aerospace Engineering Department, New York University, Brooklyn, NY 11201, USA.,Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Yichao C Wu
- Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Suman Bose
- Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Anoop Menachery
- Division of Engineering, New York University Abu Dhabi, Abu Dhabi, UAE
| | - Srikanth Talluri
- VA Boston Healthcare System, Boston, MA, USA.,Dana-Farber Cancer Institute, Boston, MA, USA
| | | | | | - Jeffrey M Karp
- Division of BioEngineering in Medicine, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Harvard Stem Cell Institute, Harvard-MIT Division of Health Sciences and Technology, 65 Landsdowne St., Cambridge, MA 02139, USA
| | - Rao H Prabhala
- VA Boston Healthcare System, Boston, MA, USA.,Dana-Farber Cancer Institute, Boston, MA, USA.,Brigham and Women's Hospital, Boston, MA, USA.,Harvard Medical School, Boston, MA, USA
| | - Rohit Karnik
- Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
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Singh G. Serum Free Light Chain Assay and κ/λ Ratio: Performance in Patients With Monoclonal Gammopathy-High False Negative Rate for κ/λ Ratio. J Clin Med Res 2016; 9:46-57. [PMID: 27924175 PMCID: PMC5127215 DOI: 10.14740/jocmr2802w] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/25/2016] [Indexed: 12/24/2022] Open
Abstract
Background Serum free light chain assay (SFLCA) and κ/λ ratio, and protein electrophoretic methods are used in the diagnosis and monitoring of monoclonal gammopathies. Methods Results for serum free light chains, serum and urine protein electrophoreses and immunofixation electrophoreses in 468 patients with a diagnosis of monoclonal gammopathy were compared. The results of the two methods were graded as concordant, non-concordant or discordant with the established diagnoses to assess the relative performance of the methods. Results of κ/λ ratio in samples with monoclonal protein detectable by electrophoretic methods were also analyzed. Results Protein electrophoreses results were concordant with the established diagnoses significantly more often than κ/λ ratio. The false negative rate for κ/λ ratio was higher than that for electrophoretic methods. κ/λ ratio was falsely negative in about 27% of the 1,860 samples with detectable monoclonal immunoglobulin. The false negative rate was higher in lesions with lambda chains (32%) than those with kappa chains (24%). The false negative rate for κ/λ ratio was over 55% in samples with monoclonal gammopathy of undetermined significance. Even at first encounter, the false negative rates for κ/λ ratios for monoclonal gammopathy of undetermined significance, smoldering myeloma and multiple myeloma were 66.98%, 23.08%, and 30.15%, respectively, with false negative rate for lambda chain lesions being higher. Conclusions Electrophoretic studies of serum and urine are superior to SFLCA and κ/λ ratio. Abnormal κ/λ ratio, per se, is not diagnostic of monoclonal gammopathy. A normal κ/λ ratio does not exclude monoclonal gammopathy. False negative rates for lesions with lambda chain are higher than those for lesions with kappa chains. Electrophoretic studies of urine are underutilized. Clinical usefulness and medical necessity of SFLCA and κ/λ ratio is of questionable value in routine clinical testing.
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Affiliation(s)
- Gurmukh Singh
- Department of Pathology, Division of Clinical Pathology, Medical College of Georgia at Augusta University, 1120 15th Street, BI 2008A, Augusta, GA 30912, USA.
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