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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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Jimenez A, Scholl AR, Wang B, Schilke M, Carlsen ED. Characteristics of isatuximab-derived interference in serum protein electrophoresis and immunofixation, and an absence of sustained in vivo interference due to belantamab mafodotin and denosumab. Clin Biochem 2024; 127-128:110761. [PMID: 38565341 DOI: 10.1016/j.clinbiochem.2024.110761] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2023] [Revised: 03/18/2024] [Accepted: 03/30/2024] [Indexed: 04/04/2024]
Abstract
OBJECTIVES Some therapeutic monoclonal antibodies, like daratumumab and elotuzumab, produce interfering monoclonal bands on serum protein electrophoresis (SPEP) and immunofixation electrophoresis (IFE). Whether other common therapeutic antibodies also produce interference has not been systematically evaluated. DESIGN AND METHODS SPEP/IFE from patients receiving isatuximab (48 patients), belantamab mafodotin (BM; 41), and denosumab (41) were retrospectively reviewed for therapeutic antibody interference. Cases exhibiting isatuximab interference were quantified and the maximum duration of isatuximab effect was evaluated. To characterize band position, neat human serum was spiked with BM or denosumab at supratherapeutic concentrations. Band migration patterns were compared on SPEP and IFE, with band position expressed relative to other constant protein fractions. RESULTS Isatuximab-induced IFE interference was common (81.3 % of evaluated patients) with a maximum observed duration of 8 weeks. 10.4 % of isatuximab patients had IgG kappa monoclonal gammopathies that co-migrated with the drug; this subset could benefit from HYDRASHIFT 2/4 isatuximab testing. 8.3 % of IFE cases were negative for an isatuximab band but showed large, endogenous M-spikes migrating elsewhere. All patients in this group expired within 1 year of this finding. We hypothesize that an inability to detect isatuximab in this setting corresponds to a large residual myeloma burden that reduces isatuximab serum concentration. This observation may serve as a negative prognostic factor. Spiking studies demonstrated that BM and denosumab produce interference in vitro, but sustained interference was not observed in >40 treated patients. CONCLUSIONS Therapeutic antibody interference in patients receiving isatuximab is common, and can persist for at least 8 weeks after administration. >10 % of patients receiving isatuximab may benefit from HYDRASHIFT testing post-therapy. In contrast, BM and denosumab fail to produce sustained interference in treated patients.
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Affiliation(s)
- Adam Jimenez
- Department of Pathology, Duke University Medical Center, Durham, NC, USA
| | - Ashley Rose Scholl
- Department of Pathology, Duke University Medical Center, Durham, NC, USA
| | - Bangchen Wang
- Department of Pathology, Duke University Medical Center, Durham, NC, USA
| | - Michael Schilke
- Department of Pharmacy, Duke University Medical Center, Durham, NC, USA
| | - Eric D Carlsen
- Department of Pathology, Duke University Medical Center, Durham, NC, USA; Duke Cancer Institute, Durham, NC, USA.
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Giles HV, Drayson MT, Kishore B, Pawlyn C, Kaiser M, Cook G, de Tute R, Owen RG, Cairns D, Menzies T, Davies FE, Morgan GJ, Pratt G, Jackson GH. Progression free survival of myeloma patients who become IFE-negative correlates with the detection of residual monoclonal free light chain (FLC) by mass spectrometry. Blood Cancer J 2024; 14:50. [PMID: 38499538 PMCID: PMC10948753 DOI: 10.1038/s41408-024-00995-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2023] [Revised: 01/17/2024] [Accepted: 01/22/2024] [Indexed: 03/20/2024] Open
Abstract
Deeper responses are associated with improved survival in patients being treated for myeloma. However, the sensitivity of the current blood-based assays is limited. Historical studies suggested that normalisation of the serum free light chain (FLC) ratio in patients who were negative by immunofixation electrophoresis (IFE) was associated with improved outcomes. However, recently this has been called into question. Mass spectrometry (MS)-based FLC assessments may offer a superior methodology for the detection of monoclonal FLC due to greater sensitivity. To test this hypothesis, all available samples from patients who were IFE negative after treatment with carfilzomib and lenalidomide-based induction and autologous stem cell transplantation (ASCT) in the Myeloma XI trial underwent FLC-MS testing. FLC-MS response assessments from post-induction, day+100 post-ASCT and six months post-maintenance randomisation were compared to serum FLC assay results. Almost 40% of patients had discordant results and 28.7% of patients with a normal FLC ratio had residual monoclonal FLC detectable by FLC-MS. FLC-MS positivity was associated with reduced progression-free survival (PFS) but an abnormal FLC ratio was not. This study demonstrates that FLC-MS provides a superior methodology for the detection of residual monoclonal FLC with FLC-MS positivity identifying IFE-negative patients who are at higher risk of early progression.
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Affiliation(s)
- H V Giles
- University Hospitals Birmingham NHS Foundation Trust, Birmingham, UK.
- University of Birmingham, Birmingham, UK.
| | | | - B Kishore
- University Hospitals Birmingham NHS Foundation Trust, Birmingham, UK
| | - C Pawlyn
- The Institute of Cancer Research, London and The Royal Marsden Hospital, London, UK
| | - M Kaiser
- The Institute of Cancer Research, London and The Royal Marsden Hospital, London, UK
| | - G Cook
- Leeds Cancer Research UK Institute of Clinical Trials Research, University of Leeds, Leeds, UK
| | - R de Tute
- Haematological Malignancy Diagnostic Service, Leeds Teaching Hospitals Trust, Leeds, UK
| | - R G Owen
- Haematological Malignancy Diagnostic Service, Leeds Teaching Hospitals Trust, Leeds, UK
| | - D Cairns
- Leeds Cancer Research UK Institute of Clinical Trials Research, University of Leeds, Leeds, UK
| | - T Menzies
- Leeds Cancer Research UK Institute of Clinical Trials Research, University of Leeds, Leeds, UK
| | - F E Davies
- Myeloma Research Program, Perlmutter Cancer, NYU Langone Health, New York, USA
| | - G J Morgan
- Myeloma Research Program, Perlmutter Cancer, NYU Langone Health, New York, USA
| | - G Pratt
- University Hospitals Birmingham NHS Foundation Trust, Birmingham, UK
- University of Birmingham, Birmingham, UK
| | - G H Jackson
- Department of Haematology, University of Newcastle, Newcastle upon Tyne, UK
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Zhu H, Liu J, Gu J, Chen M, Kuang L, Huang B, Zou W, Li J. Early M-protein immune reconstitution after autologous haematopoietic stem cell transplantation is a good prognostic marker for patients with high-risk cytogenetic multiple myeloma. Br J Haematol 2024; 204:976-987. [PMID: 38246862 DOI: 10.1111/bjh.19275] [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: 07/17/2023] [Revised: 12/14/2023] [Accepted: 12/16/2023] [Indexed: 01/23/2024]
Abstract
The presence of transient abnormal protein banding (M-protein immune reconstitution) in serum immunofixation electrophoresis after autologous haematopoietic stem cell transplantation in patients with multiple myeloma has been reported. The purpose of this study was to investigate the impact of post-transplant M-protein immune reconstitution on the prognosis of patients with multiple myeloma. M-protein immune reconstitution was observed in 25.9% (75/290) of patients. The CR rate and MRD negativity were higher in the M-protein immune reconstitution group (85.3% vs. 69.3%, p = 0.013, 81.9% vs. 66.5%, p = 0.014). Although there were no significant differences between the groups, the overall median survival time was longer in the M-protein immune reconstruction group (80 vs. 72 m, p = 0.076; not reached vs. 105 m, p = 0.312). Among patients in the cytogenetic high-risk group, the occurrence of M-protein immune reconstitution predicted better PFS and OS (80 vs. 31 m, p = 0.010; not reached vs. 91 m, p = 0.026). Additionally, in revised-International Staging System stage III patients, PFS and OS were better in those who achieved M-protein immune reconstitution (80 vs. 20 m, p = 0.025; 57 vs. 32 m, p = 0.103). The better prognosis of M-protein immune reconstitution patients may be associated with the acquisition of a deeper response. In high-risk patients, early acquisition of M-protein immune reconstitution may suggest a better prognosis.
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Affiliation(s)
- Huihui Zhu
- Haematology, Sun Yat-sen University First Affiliated Hospital, Guangzhou, Guangdong, China
| | - Junru Liu
- Haematology, Sun Yat-sen University First Affiliated Hospital, Guangzhou, Guangdong, China
| | - Jingli Gu
- Haematology, Sun Yat-sen University First Affiliated Hospital, Guangzhou, Guangdong, China
| | - Meilan Chen
- Haematology, Sun Yat-sen University First Affiliated Hospital, Guangzhou, Guangdong, China
| | - Lifen Kuang
- Haematology, Sun Yat-sen University First Affiliated Hospital, Guangzhou, Guangdong, China
| | - Beihui Huang
- Haematology, Sun Yat-sen University First Affiliated Hospital, Guangzhou, Guangdong, China
| | - Waiyi Zou
- Haematology, Sun Yat-sen University First Affiliated Hospital, Guangzhou, Guangdong, China
| | - Juan Li
- Haematology, Sun Yat-sen University First Affiliated Hospital, Guangzhou, Guangdong, China
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5
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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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6
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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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7
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Marcon C, Simeon V, Deias P, Facchin G, Corso A, Derudas D, Montefusco V, Offidani M, Petrucci MT, Zambello R, Stocchi R, Fanin R, Patriarca F. Experts' consensus on the definition and management of high risk multiple myeloma. Front Oncol 2023; 12:1096852. [PMID: 36755858 PMCID: PMC9899889 DOI: 10.3389/fonc.2022.1096852] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2022] [Accepted: 12/16/2022] [Indexed: 01/24/2023] Open
Abstract
High risk multiple myeloma (HRMM) at diagnosis is currently recognized according to the Revised International Staging System (R-ISS) which was set up in 2015. Since then, new clinical and biological prognostic factors have been developed, which could implement the definition of High Risk (HR) category. We conducted a survey in order to identify which additional parameters, both clinical and biological, are considered more useful for the clinical practice and to evaluate if the management of Multiple Myeloma (MM) should change on the basis of the risk category. A questionnaire, consisting of 8 statements, was submitted to 6 Italian experts, from the European Myeloma Network (EMN) Research Italy, using the Delphi method. The colleagues were asked to answer each question using a scale between 0 and 100. If a statement did not reach at least 75 out of 100 points from all the participants, it was rephrased on the basis of the proposal of the experts and resubmitted in a second or further round, until a consensus was reached among all. From the first round of the survey a strong consensus was reached regarding the opportunity to revise the R-ISS including chromosome 1 abnormality, TP53 mutation or deletion, circulating plasma cells by next generation flow and extramedullary plasmacytomas. No consensus was reached for the definition of "double hit" MM and for the application in clinical practice of treatment strategies based on the risk category. In the second round of the Delphi questionnaire, "double-hit" MM was recognized by the association of at least two high-risk cytogenetic or molecular abnormalities. Moreover, the experts agreed to reserve an intensified treatment only to specific conditions, such as plasma cell leukaemia or patients with multiple extramedullary plasmacytomas, while they admitted that there are not sufficient real word data in order to modify treatment on the basis of MRD assessment in clinical practice. This survey suggests that the definition of HRMM should be implemented by additional clinical and biological risk factors, that will be useful to guide treatment in the future.
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Affiliation(s)
- Chiara Marcon
- Division of Hematology, S. Maria della Misericordia Hospital, Azienda Sanitaria Universitaria Friuli Centrale, Udine, Italy,Department of Area Medica, Udine University, Udine, Italy,*Correspondence: Chiara Marcon,
| | - Valentina Simeon
- Division of Hematology, S. Maria della Misericordia Hospital, Azienda Sanitaria Universitaria Friuli Centrale, Udine, Italy,Department of Area Medica, Udine University, Udine, Italy
| | - Paola Deias
- Division of Hematology and Bone Marrow Transplant Center, Department of Medical Science, R. Binaghi Hospital, Cagliari University, Cagliari, Italy
| | - Gabriele Facchin
- Division of Hematology, S. Maria della Misericordia Hospital, Azienda Sanitaria Universitaria Friuli Centrale, Udine, Italy
| | | | - Daniele Derudas
- Division of Hematology and Bone Marrow Transplant Center, A. Businco Cancer Hospital, Cagliari, Italy
| | - Vittorio Montefusco
- Division of Hematology, Azienda Socio Sanitaria Territoriale (ASST) Santi Paolo e Carlo, Milan, Italy
| | - Massimo Offidani
- Clinical Hematology, Azienda Ospedaliera Universitaria (AOU) Ospedali Riuniti di Ancona, Ancona, Italy
| | - Maria Teresa Petrucci
- Division of Hematology, Department of Translational and Precision Medicine, Azienda Ospedaliera Policlinico Umberto I, Sapienza University of Rome, Rome, Italy
| | - Renato Zambello
- Clinical Hematology, Azienda Ospedaliera di Padova, Padua, Italy
| | - Raffaella Stocchi
- Division of Hematology, S. Maria della Misericordia Hospital, Azienda Sanitaria Universitaria Friuli Centrale, Udine, Italy
| | - Renato Fanin
- Division of Hematology, S. Maria della Misericordia Hospital, Azienda Sanitaria Universitaria Friuli Centrale, Udine, Italy,Department of Area Medica, Udine University, Udine, Italy
| | - Francesca Patriarca
- Division of Hematology, S. Maria della Misericordia Hospital, Azienda Sanitaria Universitaria Friuli Centrale, Udine, Italy,Department of Area Medica, Udine University, Udine, Italy
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8
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Cao D, Shou L, Wu Y, Dong X. The role of serum-free light chain ratios in the prediction of poor prognosis in multiple myeloma patients: a systematic review and meta-analysis. Hematology 2022; 27:1130-1139. [PMID: 36165782 DOI: 10.1080/16078454.2022.2127460] [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: 06/16/2023] Open
Abstract
BACKGROUND The association between the serum free light chain (sFLC) ratio and the prognosis of multiple myeloma (MM) patients is controversial. AIM The purpose of this study is to explore the relationship between the sFLC ratio and the prognosis of MM patients through meta-analysis. METHODS Online public databases were searched to find relevant studies. The retrieval time is limited from the establishment of the database to July 2021. The overall survival (OS) and progression-free survival (PFS) rates were compared. The results were described using hazard ratio (HR) and a 95% confidence interval (CI). Qualitative studies were also included. RESULTS A total of 9 studies involving 2864 participants were included. A pooled analysis based on four studies including newly-diagnosed MM patients, demonstrated that an abnormal sFLC ratio was associated with poor outcomes of OS (HR = 1.82, 95% CI: 1.15-2.90) and PFS (HR = 1.87, 95% CI: 1.20-2.90). Three qualitative studies showed that an abnormal sFLC ratio was related with poor outcomes of OS (studies all included newly diagnosed MM patients) and PFS (two studies included newly-diagnosed MM patients and one study included non-newly-diagnosed MM patients). Two studies stated that the sFLC ratio is not associated with OS (both studies included non-newly-diagnosed MM patients) and one study reported that the sFLC ratio is not associated with PFS (study included non-newly-diagnosed MM patients). CONCLUSION sFLC ratio could be used to predict adverse outcomes in newly-diagnosed MM patients, but is not suitable for non-newly-diagnosed MM patients.
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Affiliation(s)
- Dan Cao
- Department of Hematology, Huzhou Central Hospital, Affiliated Central Hospital of Huzhou University, Huzhou, People's Republic of China
| | - Lihong Shou
- Department of Hematology, Huzhou Central Hospital, Affiliated Central Hospital of Huzhou University, Huzhou, People's Republic of China
| | - Ying Wu
- Department of Hematology, Huzhou Central Hospital, Affiliated Central Hospital of Huzhou University, Huzhou, People's Republic of China
| | - Xiaohui Dong
- Department of Hematology, Huzhou Central Hospital, Affiliated Central Hospital of Huzhou University, Huzhou, People's Republic of China
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9
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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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10
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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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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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12
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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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13
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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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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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Grady JL, Avery A, Moore AR, Harris LJ, Kakar N, Rout ED. Progressive gammopathy and coagulopathy in a young English bulldog. THE CANADIAN VETERINARY JOURNAL = LA REVUE VETERINAIRE CANADIENNE 2021; 62:160-166. [PMID: 33542555 PMCID: PMC7808204] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
A restricted polyclonal or biclonal gammopathy resulting in bleeding tendencies was diagnosed in a young, neutered male English bulldog with concurrent splenomegaly, anemia, and severe elevations in IgM and, to a lesser degree, IgA immunoglobulins. There was a positive clinical response to treatment with prednisone and chlorambucil. This case bears similarity to a recently published syndrome of polyclonal gammopathy that is not neoplastic in origin in this breed. Key clinical message: The current case describes the management and clinical course of a recently described syndrome of polyclonal gammopathy in English bulldogs.
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Affiliation(s)
- Jennifer L Grady
- Tufts University, Cummings School of Veterinary Medicine, Department of Clinical Sciences, 200 Westboro Road, North Grafton, Massachusetts 01536, USA (Grady, Kakar); Colorado State University, College of Veterinary Medicine and Biomedical Science, Department of Microbiology, Immunology, and Pathology, 200 West Lake Street, Fort Collins, Colorado 80523 USA (Avery, Moore, Harris, Rout)
| | - Anne Avery
- Tufts University, Cummings School of Veterinary Medicine, Department of Clinical Sciences, 200 Westboro Road, North Grafton, Massachusetts 01536, USA (Grady, Kakar); Colorado State University, College of Veterinary Medicine and Biomedical Science, Department of Microbiology, Immunology, and Pathology, 200 West Lake Street, Fort Collins, Colorado 80523 USA (Avery, Moore, Harris, Rout)
| | - A Russell Moore
- Tufts University, Cummings School of Veterinary Medicine, Department of Clinical Sciences, 200 Westboro Road, North Grafton, Massachusetts 01536, USA (Grady, Kakar); Colorado State University, College of Veterinary Medicine and Biomedical Science, Department of Microbiology, Immunology, and Pathology, 200 West Lake Street, Fort Collins, Colorado 80523 USA (Avery, Moore, Harris, Rout)
| | - Lauren J Harris
- Tufts University, Cummings School of Veterinary Medicine, Department of Clinical Sciences, 200 Westboro Road, North Grafton, Massachusetts 01536, USA (Grady, Kakar); Colorado State University, College of Veterinary Medicine and Biomedical Science, Department of Microbiology, Immunology, and Pathology, 200 West Lake Street, Fort Collins, Colorado 80523 USA (Avery, Moore, Harris, Rout)
| | - Neketa Kakar
- Tufts University, Cummings School of Veterinary Medicine, Department of Clinical Sciences, 200 Westboro Road, North Grafton, Massachusetts 01536, USA (Grady, Kakar); Colorado State University, College of Veterinary Medicine and Biomedical Science, Department of Microbiology, Immunology, and Pathology, 200 West Lake Street, Fort Collins, Colorado 80523 USA (Avery, Moore, Harris, Rout)
| | - Emily D Rout
- Tufts University, Cummings School of Veterinary Medicine, Department of Clinical Sciences, 200 Westboro Road, North Grafton, Massachusetts 01536, USA (Grady, Kakar); Colorado State University, College of Veterinary Medicine and Biomedical Science, Department of Microbiology, Immunology, and Pathology, 200 West Lake Street, Fort Collins, Colorado 80523 USA (Avery, Moore, Harris, Rout)
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16
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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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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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18
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Audit of the Prevalence of Noncorrelation of Immunofixation with Protein Electrophoresis and Serum Free Light Chain Assays in Multiple Myeloma in a Tertiary Cancer Care Center. Indian J Clin Biochem 2020; 36:353-359. [PMID: 34220011 DOI: 10.1007/s12291-020-00924-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2020] [Accepted: 09/01/2020] [Indexed: 10/23/2022]
Abstract
Multiple myeloma (MM) is diagnosed and monitored by correlating panel of test results including serum Protein electrophoresis (SPE), Immunofixation electrophoresis (IFE), serum Free Light chain (sFLC) measurements. This audit is aimed to evaluate the prevalence of non-correlation and discrepancies amongst the three investigations (SPE/IFE/sFLC) for assessment of MM. 106 MM patients were reviewed over 16 months in a tertiary cancer care center by the availability of 3 serum test results (SPE/IFE/sFLC). Patients were divided into 2 groups: group1, newly diagnosed MM patients who were yet to receive myeloma specific treatment (n = 48); and group2, already diagnosed MM patients on treatment and followup (n = 58). Treatment modalities included stem cell transplantation and standard chemotherapy regimens. Non-correlation between the three test results (IFE/SPE/sFLC) was observed (21% in group1 and 45% in group2). Three types of discrepancies were detected as follows: (a) IFE showing less number of restriction bands as compared to SPE (8.6% patients in group2); (b) SPE/IFE negative with an abnormal sFLC ratio (12.5% patients in group1 and 13.7% in group2); (c) SPE/IFE positive but normal sFLC ratio (8% in group1 and 22% in group2). To conclude, IFE may sometimes provide information that does not always correlate with either of the SPE or sFLC results due to different sensitivities, antigen-antibody interactions, or treatment. Hence, SPE plus sFLC may be more useful particularly for patients on follow-up while IFE plus sFLC may help screen the new patients. The judicious selection of the biochemical assays can effectively reduce the treatment cost in a developing country like India.
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19
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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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20
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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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21
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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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22
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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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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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