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Farnsworth CW, Roemmich B, Spears GM, Murray DL, Dispenzieri A, Willrich MAV. Clinical specificity of two assays for immunoglobulin kappa and lambda free light chains. Clin Chem Lab Med 2024; 62:929-938. [PMID: 38044587 DOI: 10.1515/cclm-2023-0912] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2023] [Accepted: 11/03/2023] [Indexed: 12/05/2023]
Abstract
OBJECTIVES Free light chain (FLC) assays and the ratio of κ/λ are recommended for diagnosis, prognosis and monitoring of plasma cell dyscrasias (PCD). Limited data exists on FLC clinical specificity in patients diagnosed with other conditions. METHODS We assessed the κ, λ, and κ/λ FLC ratio using the FreeLite assay and the Sebia FLC ELISA assay in 176 patients with clinical presentations of fatigue, anemia, polyclonal hypergammaglobulinemia, joint disorders, kidney disease and non PCD-cancers with no monoclonal protein observed on serum protein electrophoresis or MASS-FIX immunoglobulin isotyping. Manufacturer defined reference intervals (RI) and glomerular filtration rate (GFR) specific RI (renal RI) were utilized. RESULTS For the κ/λ ratio, 68.7 % (121/176) of specimens on the FreeLite and 87.5 % (154/176) of specimens on the Sebia assay were within RI. For κ, 68.2 % (120/176) and 72.2 % (127/176) of results were outside RI for FreeLite and Sebia respectively. For λ, 37.5 % (66/176) and 84.1 % (148/176) of FreeLite and Sebia results were outside RI. With FreeLite and Sebia, patients with kidney disease (n=25) had the highest κ/λ ratios. 44 patients (25.0 %) had GFR <60 mL/min/BSA. When renal RI were applied, 13.6 % had a FLCr outside the renal RI with FreeLite, and 4.5 % with Sebia. CONCLUSIONS In a cohort of patients with signs and symptoms suggestive of PCDs, but ultimately diagnosed with other conditions, Sebia FLC had improved clinical specificity relative to FreeLite, if one was using an abnormal κ/λ ratio as a surrogate for monoclonality.
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Affiliation(s)
| | | | - Grant M Spears
- Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN, USA
| | - David L Murray
- Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN, USA
| | - Angela Dispenzieri
- Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN, USA
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2
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Li B, King R, Chan B, Rollo C, Thompson S, Florkowski C. An updated diagnostic range for serum free light chain kappa/lambda ratio using Freelite reagents on BN II or Optilite. Pathology 2024:S0031-3025(24)00098-9. [PMID: 38705800 DOI: 10.1016/j.pathol.2024.02.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2023] [Revised: 01/24/2024] [Accepted: 02/06/2024] [Indexed: 05/07/2024]
Affiliation(s)
- Bobby Li
- Specialist Biochemistry, Canterbury Health Laboratories, Te Whatu Ora Health New Zealand Waitaha Canterbury, Christchurch, New Zealand.
| | - Richard King
- Specialist Biochemistry, Canterbury Health Laboratories, Te Whatu Ora Health New Zealand Waitaha Canterbury, Christchurch, New Zealand
| | - Becca Chan
- Protein Laboratory, Canterbury Health Laboratories, Te Whatu Ora Health New Zealand Waitaha Canterbury, Christchurch, New Zealand
| | - Catherine Rollo
- Protein Laboratory, Canterbury Health Laboratories, Te Whatu Ora Health New Zealand Waitaha Canterbury, Christchurch, New Zealand
| | - Simon Thompson
- Specialist Biochemistry, Canterbury Health Laboratories, Te Whatu Ora Health New Zealand Waitaha Canterbury, Christchurch, New Zealand
| | - Chris Florkowski
- Specialist Biochemistry, Canterbury Health Laboratories, Te Whatu Ora Health New Zealand Waitaha Canterbury, Christchurch, New Zealand
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3
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Chong YP, Lim SM, Loh TP, Mollee P, Wijeratne N, Choy KW. Screening for and diagnosis of monoclonal gammopathy. J Clin Pathol 2023; 76:727-733. [PMID: 37604683 DOI: 10.1136/jcp-2023-208774] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2023] [Accepted: 08/03/2023] [Indexed: 08/23/2023]
Abstract
Monoclonal gammopathy is a spectrum of disorders characterised by clonal proliferation of plasma cells or lymphocytes, which produce abnormal immunoglobulin or its components (monoclonal proteins). Monoclonal gammopathies are often categorised as low-tumour-burden diseases (eg, amyloid light chain (AL) amyloidosis), premalignant disorders (such as monoclonal gammopathy of undetermined significance and smouldering multiple myeloma), and malignancies (eg, multiple myeloma and Waldenström's macroglobulinaemia). Such diversity of concentration and structure makes monoclonal protein a challenging clonal marker. This article provides an overview on initial laboratory testing of monoclonal gammopathy to guide clinicians and laboratory professionals in the selection and interpretation of appropriate investigations.
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Affiliation(s)
- Yuh Ping Chong
- School of Health and Biomedical Sciences, RMIT University, Bundoora, Victoria, Australia
| | - Say Min Lim
- Department of Pathology, Hospital Teluk Intan, Teluk Intan, Malaysia
| | - Tze Ping Loh
- Department of Laboratory Medicine, National University Hospital, Singapore
| | - Peter Mollee
- Pathology Queensland, Princess Alexandra Hospital, Brisbane, Queensland, Australia
- School of Medicine, The University of Queensland, Brisbane, Queensland, Australia
| | - Nilika Wijeratne
- Dorevitch Pathology, Heidelberg, Victoria, Australia
- School of Clinical Sciences at Monash Health, Department of Medicine, Nursing and Health Sciences, Monash University, Clayton, Victoria, Australia
- Eastern Health Pathology, Eastern Health, Box Hill, Victoria, Australia
| | - Kay Weng Choy
- Department of Pathology, Northern Health, Epping, Victoria, Australia
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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] [What about the content of this article? (0)] [Affiliation(s)] [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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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] [What about the content of this article? (0)] [Affiliation(s)] [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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Morales-García LJ, Lillo Rodríguez RM, Pacheco-Delgado MS. Freelite and Kloneus assays in free light chain measurements in patients with renal impairment. Clin Biochem 2023:110610. [PMID: 37429509 DOI: 10.1016/j.clinbiochem.2023.110610] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2023] [Revised: 05/14/2023] [Accepted: 07/05/2023] [Indexed: 07/12/2023]
Abstract
BACKGROUND Serum free light chain (FLC) quantification is a diagnostic criterion for monoclonal gammopathy and its values in patients with renal impairment are different from those in healthy subjects. The aim of this study was to evaluate Freelite and Kloneus assays in these patients METHODS: In this retrospective study, serum samples from 226 patients with chronic kidney disease (CKD) of stages 2-5 were measured with a Freelite assay on the Optilite system and with a Kloneus assay on the AU5800 system and compared with controls without renal impairment. RESULTS Both kappa FLC (K-FLC) and lambda FLC (L-FLC) concentrations increased with Kloneus and Freelite assays with each increment in CKD stage. In patients with CKD, Kloneus detected lower concentrations of K-FLC (median: 20.4 mg/L; 95% range: 9.8-57.2) than Freelite (median: 36.5 mg/L; 95% range: 16.5-137.7) and higher concentrations of L-FLC (median: 32.2 mg/L; 95% range: 14.4-96.7) than Freelite (median: 25.4 mg/L; 95% range: 11.9-86.0). This resulted in significantly different kappa/lambda ratios (K/L-FLC) in patients with CKD for the two tests. The Freelite K/L-FLC in the CKD group (median: 1.50; min-max: 0.66-3.45) was significantly increased compared with healthy controls, and the Kloneus K/L-FLC in the CKD group (median: 0.63; 95% min-max: 0.34-1.01) was slightly lower. CONCLUSIONS These findings demonstrate that Freelite and Kloneus assays provide higher but not parallel values when FLCs are measured in patients with CKD, so an increase in K/L-FLC was observed in the case of Freelite, and we found a slight decrease in the case of Kloneus.
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Affiliation(s)
- Luis J Morales-García
- Department of Clinical Laboratory, Hospital Universitario de Fuenlabrada, Camino del Molino 2, 28942 Fuenlabrada (Madrid), Spain.
| | - Rosa M Lillo Rodríguez
- Department of Clinical Laboratory, Hospital Universitario de Fuenlabrada, Camino del Molino 2, 28942 Fuenlabrada (Madrid), Spain.
| | - María S Pacheco-Delgado
- Department of Clinical Laboratory, Hospital Universitario de Fuenlabrada, Camino del Molino 2, 28942 Fuenlabrada (Madrid), Spain.
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7
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Omosule CL, Hock KG, Dalton C, Scalpati A, Gronowski AM, Brants A, Farnsworth CW. Method Comparison and Workflow Differences Using the Same Free Light Chain Assay on 2 Analyzer Platforms. J Appl Lab Med 2023; 8:689-699. [PMID: 37186660 DOI: 10.1093/jalm/jfad020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2022] [Accepted: 02/13/2023] [Indexed: 05/17/2023]
Abstract
BACKGROUND The Freelite assay (The Binding Site) is utilized to quantify serum immunoglobulin free light chains (sFLC), which is crucial for diagnosing and monitoring plasma cell dyscrasias (PCDs). Using the Freelite test, we compared methods and evaluated workflow differences across two analyzer platforms. METHODS sFLC concentrations were measured in 306 fresh serum specimens (cohort A) and 48 frozen specimens with documented sFLC >20 mg/dL (cohort B). Specimens were analyzed on the Roche cobas 8000 and Optilite analyzers using the Freelite κ and λ assays. Performance was compared using Deming regression. Workflow was compared by assessing turnaround time (TAT) and reagent usage. RESULTS For cohort A specimens, Deming regression revealed a slope of 1.04 (95% CI, 0.88-1.02) and an intercept of -0.77 (95% CI, -0.57 to 1.85) for sFLCκ and a slope of 0.90 (95% CI, -0.04 to 1.83) and intercept of 1.59 (95% CI, -3.12 to 6.25) for sFLCλ. Regression of the κ/λ ratio revealed a slope of 2.44 (95% CI, 1.47-3.41) and intercept of -8.13 (95% CI, -16.82 to 0.58) with a concordance kappa of 0.80 (95% CI, 0.69-0.92). The proportion of specimens with TAT >60 min was 0.33% and 8% for the Optilite and cobas, respectively (P < 0.001). The Optilite required 49 (P < 0.001) and 12 (P = 0.016) fewer tests for sFLCκ and sFLCλ relative to the cobas. Cohort B specimens showed similar but more dramatic results. CONCLUSIONS Analytical performance of the Freelite assays was comparable on the Optilite and cobas 8000 analyzers. In our study, the Optilite required less reagent, had a slightly reduced TAT, and eliminated manual dilutions for samples with sFLC concentrations >20 mg/dL.
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Affiliation(s)
- Catherine L Omosule
- Department of Pathology & Immunology, Washington University in St. Louis School of Medicine, St. Louis, MO, United States
| | - Karl G Hock
- Department of Pathology & Immunology, Washington University in St. Louis School of Medicine, St. Louis, MO, United States
| | - Claire Dalton
- Department of Pathology & Immunology, Washington University in St. Louis School of Medicine, St. Louis, MO, United States
| | | | - Ann M Gronowski
- Department of Pathology & Immunology, Washington University in St. Louis School of Medicine, St. Louis, MO, United States
| | - Aigars Brants
- The Binding Site, Inc., San Diego, CA, United States
| | - Christopher W Farnsworth
- Department of Pathology & Immunology, Washington University in St. Louis School of Medicine, St. Louis, MO, United States
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Myllynen C, Sarkkinen J, Atula S, Tienari P, Kekäläinen E, Laakso SM. A skewed ratio of free light chains is more common in patients with late-onset than early-onset myasthenia gravis. Immunol Lett 2023; 260:S0165-2478(23)00113-X. [PMID: 37414259 DOI: 10.1016/j.imlet.2023.07.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2023] [Revised: 06/25/2023] [Accepted: 07/03/2023] [Indexed: 07/08/2023]
Abstract
Myasthenia gravis (MG) is an autoantibody-mediated neuromuscular disease with an unpredictable clinical course. Serum free light chains (FLCs) have risen as a promising biomarker for MG, but their role in different subtypes of MG and in predicting disease progression is still uncharted. We investigated plasma from 58 generalized MG patients during post-thymectomy follow-up to determine κ and λ FLC and κ/λ ratio. In a subcohort of 30 patients, we examined the expression of 92 proteins associated with immuno-oncology using Olink. We further studied the ability of FLCs or proteomic markers to differentiate disease severity. Patients with late-onset MG (LOMG) displayed significantly higher mean κ/λ ratio than patients with early-onset MG (P=0.004). Inducible T-cell co-stimulator ligand (ICOSLG), matrix metalloproteinase 7 (MMP7), hepatocyte growth factor (HGF), and arginase 1 (ARG1) were differentially expressed in MG patients compared to healthy controls. There were no significant associations between clinical outcomes and FLCs or the assayed proteins. In conclusion, an elevated κ/λ ratio suggests long-lasting aberrant clonal plasma cell function in LOMG. Immuno-oncology-related proteomic analysis showed alterations in immunoregulatory pathways. Our findings pinpoint the FLC ratio as a biomarker for LOMG and call for further investigation of the immunoregulatory pathways in MG.
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Affiliation(s)
- Chris Myllynen
- Department of Neurosciences, University of Helsinki, Helsinki, Finland.
| | - Joona Sarkkinen
- Translational Immunology Research Program, University of Helsinki, Helsinki, Finland
| | - Sari Atula
- Department of Neurosciences, University of Helsinki, Helsinki, Finland; Department of Neurology, Neurocenter, Helsinki University Hospital, Helsinki, Finland
| | - Pentti Tienari
- Translational Immunology Research Program, University of Helsinki, Helsinki, Finland; Department of Neurology, Neurocenter, Helsinki University Hospital, Helsinki, Finland
| | - Eliisa Kekäläinen
- Translational Immunology Research Program, University of Helsinki, Helsinki, Finland; HUS Diagnostic Center, HUSLAB Clinical Microbiology, Helsinki University Hospital, Helsinki, Finland
| | - Sini M Laakso
- Department of Neurosciences, University of Helsinki, Helsinki, Finland; Translational Immunology Research Program, University of Helsinki, Helsinki, Finland; Department of Neurology, Neurocenter, Helsinki University Hospital, Helsinki, Finland
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Schroeder LF. Retrospective Analysis of Serum Free Light Chain Reference Intervals and Risk for Monoclonal Gammopathy Suggests Different Limits Than Those in International Guidelines. Clin Biochem 2023:110604. [PMID: 37394225 DOI: 10.1016/j.clinbiochem.2023.110604] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2023] [Revised: 06/03/2023] [Accepted: 06/23/2023] [Indexed: 07/04/2023]
Abstract
OBJECTIVES Recent reference interval studies of the serum free light chain (FLC) test using contemporary instruments display divergence with the diagnostic range generally adopted as the international standard. In this study, we perform a retrospective reference interval analysis with risk predictions for monoclonal gammopathy. METHODS Retrospective laboratory and clinical data for 8,986 patients were included in the study. Reference intervals were generated against a set of inclusion/exclusion criteria for two time periods representing the use of different instruments. The presence of monoclonal gammopathy was established from diagnostic test interpretations and EHR diagnosis codes in the patient problem lists and medical history. RESULTS The 95% FLC ratio reference intervals were 0.76-2.38 for SPAPLUS®, and 0.68-1.82 for Optilite® instruments. These intervals varied considerably from the current diagnostic range of 0.26-1.65 and mapped approximately to the FLC ratios beyond which risk of monoclonal gammopathy substantially increased. CONCLUSIONS These findings corroborate recent reference interval studies and support recommendations for independent re-evaluation of intervals by institutions as well as an update of international guidelines.
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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] [What about the content of this article? (0)] [Affiliation(s)] [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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Hegen H, Arrambide G, Gnanapavan S, Kaplan B, Khalil M, Saadeh R, Teunissen C, Tumani H, Villar LM, Willrich MAV, Zetterberg H, Deisenhammer F. Cerebrospinal fluid kappa free light chains for the diagnosis of multiple sclerosis: A consensus statement. Mult Scler 2023; 29:182-195. [PMID: 36527368 PMCID: PMC9925908 DOI: 10.1177/13524585221134217] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Cerebrospinal fluid (CSF) analysis is of utmost importance for diagnosis and differential diagnosis of patients with suspected multiple sclerosis (MS). Evidence of intrathecal immunoglobulin G (IgG) synthesis proves the inflammatory nature of the disease, increases diagnostic certainty and substitutes for dissemination in time according to current diagnostic criteria. The gold standard to determine intrathecal IgG synthesis is the detection of CSF-restricted oligoclonal bands (OCBs). However, advances in laboratory methods brought up κ-free light chains (FLCs) as a new biomarker, which are produced in excess over intact immunoglobulins and accumulate in CSF in the case of central nervous system-derived inflammation. Overwhelming evidence showed a high diagnostic accuracy of intrathecal κ-FLC synthesis in MS with sensitivity and specificity of approximately 90% similar to OCB. κ-FLCs have advantages as its detection is fast, easy, cost-effective, reliable, rater-independent and returning quantitative results which might also improve the value of predicting MS disease activity. An international panel of experts in MS and CSF diagnostics developed a consensus of all participants. Six recommendations are given for establishing standard CSF evaluation in patients suspected of having MS. The panel recommended to include intrathecal κ-FLC synthesis in the next revision of MS diagnostic criteria as an additional tool to measure intrathecal immunoglobulin synthesis.
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Affiliation(s)
- Harald Hegen
- Department of Neurology, Medical University of Innsbruck, Innsbruck, Austria
| | - Georgina Arrambide
- Servei de Neurologia-Neuroimmunologia, Centre d'Esclerosi Múltiple de Catalunya (Cemcat), Vall d'Hebron Hospital Universitari, Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Sharmilee Gnanapavan
- Blizard Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London, UK
| | - Batia Kaplan
- Laboratory of Hematology, Sheba Medical Center, Ramat Gan, Israel
| | - Michael Khalil
- Department of Neurology, Medical University of Graz, Graz, Austria
| | - Ruba Saadeh
- Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN, USA/Department of Neurology, Mayo Clinic, Rochester, MN, USA
| | - Charlotte Teunissen
- Neurochemistry Laboratory, Department of Clinical Chemistry, Amsterdam Neuroscience, Program Neuroinflammation, Vrije Universiteit Amsterdam, Amsterdam UMC, Amsterdam, The Netherlands
| | - Hayrettin Tumani
- CSF Laboratory, Department of Neurology, University of Ulm, Ulm, Germany
| | - Luisa Maria Villar
- Biostatistics Unit, Department of Immunology, Hospital Universitario Ramón y Cajal, Madrid, Spain
| | | | - Henrik Zetterberg
- Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden/Clinical Neurochemistry Laboratory, Sahlgrenska University Hospital, Gothenburg, Sweden/Department of Neurodegenerative Disease, UCL Queen Square Institute of Neurology, London, UK/UK Dementia Research Institute at UCL, London, UK/Hong Kong Center for Neurodegenerative Diseases, Hong Kong, China
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Minnema MC, Jacobs JFM. In response to: Defining new reference intervals for serum free light chains in individuals with chronic kidney disease: results of the iStopMM study. Blood Cancer J 2022; 12:152. [DOI: 10.1038/s41408-022-00751-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2022] [Revised: 11/01/2022] [Accepted: 11/03/2022] [Indexed: 11/16/2022] Open
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Abroud H, Beldi‐Ferchiou A, Audard V, Lemonnier F, Le Bras F, Belhadj K, Moktefi A, Poullot E, El Karoui K, Dupuis J, Maarek A, Roulin L, Delfau‐Larue M, Oghina S, Kharoubi M, Bézard M, Zaroui A, Damy T, Molinier‐Frenkel V. Evaluation of a new ELISA assay for monoclonal free‐light chain detection in patients with cardiac amyloidosis. eJHaem 2022; 3:828-837. [PMID: 36051065 PMCID: PMC9421952 DOI: 10.1002/jha2.516] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/11/2022] [Revised: 06/08/2022] [Accepted: 06/10/2022] [Indexed: 11/27/2022]
Abstract
The causal protein of amyloid light‐chain (AL) amyloidosis is a monoclonal immunoglobulin free light chain (mFLC), which must be quantified in the serum for patient diagnosis and monitoring. Several manufacturers commercialize immunoassays that quantify total kappa (κ) and lambda (λ) FLC, but results can differ greatly between these tests. Here, we compared a recently developed enzyme‐linked immunosorbent assay (ELISA) (Sebia) with N‐Latex immunonephelometry (Siemens) in 96 patients diagnosed with AL amyloidosis (histologically confirmed) and 48 non‐AL patients sent to our referral center for suspicion of cardiac amyloidosis. ELISA free‐light chain difference (dFLC) were lower than N‐Latex values, and agreement between methods was reduced in the case of involved λ FLC. Diagnosis sensitivity and specificity were >85% with both assays. A receiver operating characteristic analysis indicated that ELISA performances could be improved by using a higher value for the lower limit of the κ/λ ratio. We also assessed Freelite (The Binding Site) in a subgroup of these same AL patients, including 18 cases with normal κ/λ ratio by at least one assay. Only two patients had normal κ/λ ratio with all three assays. Overall, ELISA demonstrated slightly lower sensitivity than N‐Latex but may be an alternative to nephelometry/turbidimetry in certain difficult cases.
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Affiliation(s)
- Hajer Abroud
- Département d'Hématologie‐Immunologie AP‐HP, Hopital Henri Mondor Creteil France
| | - Asma Beldi‐Ferchiou
- Département d'Hématologie‐Immunologie AP‐HP, Hopital Henri Mondor Creteil France
- INSERM IMRB Univ Paris Est Creteil Creteil France
| | - Vincent Audard
- French Referral Centre for Cardiac Amyloidosis Cardiogen Network GRC Amyloid Research Institute Henri Mondor Hospital Creteil France
- Service de Néphrologie et Transplantation AP‐HP, Hopital Henri Mondor Creteil France
| | - François Lemonnier
- French Referral Centre for Cardiac Amyloidosis Cardiogen Network GRC Amyloid Research Institute Henri Mondor Hospital Creteil France
- Unité Hémopathies Lymphoïdes AP‐HP, Hopital Henri Mondor Creteil France
| | - Fabien Le Bras
- French Referral Centre for Cardiac Amyloidosis Cardiogen Network GRC Amyloid Research Institute Henri Mondor Hospital Creteil France
- Unité Hémopathies Lymphoïdes AP‐HP, Hopital Henri Mondor Creteil France
| | - Karim Belhadj
- French Referral Centre for Cardiac Amyloidosis Cardiogen Network GRC Amyloid Research Institute Henri Mondor Hospital Creteil France
- Unité Hémopathies Lymphoïdes AP‐HP, Hopital Henri Mondor Creteil France
| | - Anissa Moktefi
- French Referral Centre for Cardiac Amyloidosis Cardiogen Network GRC Amyloid Research Institute Henri Mondor Hospital Creteil France
- Département de Pathologie AP‐HP, Hopital Henri Mondor Creteil France
| | - Elsa Poullot
- French Referral Centre for Cardiac Amyloidosis Cardiogen Network GRC Amyloid Research Institute Henri Mondor Hospital Creteil France
- Département de Pathologie AP‐HP, Hopital Henri Mondor Creteil France
| | - Khalil El Karoui
- French Referral Centre for Cardiac Amyloidosis Cardiogen Network GRC Amyloid Research Institute Henri Mondor Hospital Creteil France
- Service de Néphrologie et Transplantation AP‐HP, Hopital Henri Mondor Creteil France
| | - Jehan Dupuis
- French Referral Centre for Cardiac Amyloidosis Cardiogen Network GRC Amyloid Research Institute Henri Mondor Hospital Creteil France
- Unité Hémopathies Lymphoïdes AP‐HP, Hopital Henri Mondor Creteil France
| | - Alizée Maarek
- French Referral Centre for Cardiac Amyloidosis Cardiogen Network GRC Amyloid Research Institute Henri Mondor Hospital Creteil France
- Unité Hémopathies Lymphoïdes AP‐HP, Hopital Henri Mondor Creteil France
| | - Louise Roulin
- French Referral Centre for Cardiac Amyloidosis Cardiogen Network GRC Amyloid Research Institute Henri Mondor Hospital Creteil France
- Unité Hémopathies Lymphoïdes AP‐HP, Hopital Henri Mondor Creteil France
| | - Marie‐Hélène Delfau‐Larue
- Département d'Hématologie‐Immunologie AP‐HP, Hopital Henri Mondor Creteil France
- INSERM IMRB Univ Paris Est Creteil Creteil France
| | - Silvia Oghina
- French Referral Centre for Cardiac Amyloidosis Cardiogen Network GRC Amyloid Research Institute Henri Mondor Hospital Creteil France
- Département de Cardiologie AP‐HP, Hopital Henri Mondor Creteil France
| | - Mounira Kharoubi
- French Referral Centre for Cardiac Amyloidosis Cardiogen Network GRC Amyloid Research Institute Henri Mondor Hospital Creteil France
- Département de Cardiologie AP‐HP, Hopital Henri Mondor Creteil France
| | - Mélanie Bézard
- French Referral Centre for Cardiac Amyloidosis Cardiogen Network GRC Amyloid Research Institute Henri Mondor Hospital Creteil France
- Département de Cardiologie AP‐HP, Hopital Henri Mondor Creteil France
| | - Amira Zaroui
- French Referral Centre for Cardiac Amyloidosis Cardiogen Network GRC Amyloid Research Institute Henri Mondor Hospital Creteil France
- Département de Cardiologie AP‐HP, Hopital Henri Mondor Creteil France
| | - Thibaud Damy
- French Referral Centre for Cardiac Amyloidosis Cardiogen Network GRC Amyloid Research Institute Henri Mondor Hospital Creteil France
- Département de Cardiologie AP‐HP, Hopital Henri Mondor Creteil France
- INSERM, IMRB, CEPiaA Univ Paris Est Creteil Creteil France
| | - Valérie Molinier‐Frenkel
- Département d'Hématologie‐Immunologie AP‐HP, Hopital Henri Mondor Creteil France
- INSERM IMRB Univ Paris Est Creteil Creteil France
- French Referral Centre for Cardiac Amyloidosis Cardiogen Network GRC Amyloid Research Institute Henri Mondor Hospital Creteil France
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14
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Van Hoovels L, Vercammen M, Nevejan L, Cornette M, Briers PJ, Deeren D, Van Droogenbroeck J, Fostier K, De Smet D. Serum free light chain analysis: persisting limitations with new kids on the block. Clin Chem Lab Med 2022; 60:1440-1448. [PMID: 35781357 DOI: 10.1515/cclm-2022-0347] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2022] [Accepted: 06/21/2022] [Indexed: 11/15/2022]
Abstract
OBJECTIVES Serum free light chain (sFLC) measurements have inherent analytical limitations impacting sFLC clinical interpretation. We evaluated analytical and diagnostic performance of three polyclonal sFLC assays on four analytical platforms. METHODS sFLC concentration was measured using Diazyme FLC assays (Diazyme) on cobas c501/c503 analyzer (Roche); Freelite assays (The Binding Site) on Optilite analyzer (The Binding Site) and cobas c501 analyzer and Sebia FLC ELISA assays (Sebia) on AP22 ELITE analyzer (DAS). Imprecision, linearity, method comparison vs. Freelite/Optilite, antigen excess detection and reference value verification were assessed. Diagnostic performance was compared on 120 serum samples and on follow-up samples of five patients with κ and λ monoclonal gammopathy. RESULTS Method comparison showed excellent correlation with Freelite/Optilite method for all assays. A large proportional negative bias was shown for both Sebia κ and λ ELISA and a significant positive proportional bias for λ in the low (<10 mg/L) Freelite/cobas c501 method. Clinically relevant underestimation of κ sFLC levels due to antigen excess was shown for 7% of each Diazyme/cobas application and for 11 and 32.1% of λ sFLC assay of respectively Diazyme/cobas and Sebia/AP22. sFLC reference values revealed application specific. Cohen's κ values were (very) good for κ sFLC but only moderate to good for λ sFLC. In 4/10 follow-up patients, significant differences in clinical interpretation between sFLC assays were noticed. CONCLUSIONS Important analytical limitations remain for all sFLC applications. Differences in reference values and diagnostic performance hamper interchangeability of sFLC assays. Assay specific sFLC decision guidelines are warranted.
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Affiliation(s)
- Lieve Van Hoovels
- Department of Laboratory Medicine, OLV Hospital Aalst, Aalst, Belgium.,Department of Microbiology, Immunology and Transplantation, KU Leuven, Leuven, Belgium
| | - Martine Vercammen
- Department of Laboratory Medicine, AZ Sint-Jan Hospital Brugge - Oostende AV, Bruges, Belgium.,Research group REIM, Vrije Universiteit Brussel (VUB), Brussels, Belgium
| | - Louis Nevejan
- Department of Laboratory Medicine, OLV Hospital Aalst, Aalst, Belgium.,Department of Laboratory Medicine, University Hospital Leuven, Leuven, Belgium
| | - Margot Cornette
- Department of Laboratory Medicine, AZ Delta Hospital, Roeselare, Belgium.,Department of Laboratory Medicine, University Hospital Ghent, Ghent, Belgium
| | - Pieter-Jan Briers
- Department of Laboratory Medicine, AZ Sint-Jan Hospital Brugge - Oostende AV, Bruges, Belgium.,Department of Laboratory Medicine, University Hospital Leuven, Leuven, Belgium
| | - Dries Deeren
- Department of Hematology, AZ Delta Hospital, Roeselare, Belgium
| | - Jan Van Droogenbroeck
- Department of Hematology, AZ Sint-Jan Hospital Brugge - Oostende AV, Bruges, Belgium
| | - Karel Fostier
- Department of Hematology, OLV Hospital, Aalst, Belgium
| | - Dieter De Smet
- Department of Laboratory Medicine, AZ Delta Hospital, Roeselare, Belgium
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15
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Zhu G, Fu X, Ren Y, Wang Y, Wang S, An G. Comparative analysis of three serum‐free light‐chain detection systems in the diagnosis of multiple myeloma. Int J Lab Hematol 2022; 44:576-581. [DOI: 10.1111/ijlh.13790] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2021] [Revised: 11/02/2021] [Accepted: 12/02/2021] [Indexed: 11/27/2022]
Affiliation(s)
- Guoqing Zhu
- State Key Laboratory of Experimental Hematology, National Clinical Research Center for Blood Diseases, Haihe Laboratory of Cell Ecosystem, Institute of Hematology & Blood Diseases Hospital Chinese Academy of Medical Sciences & Peking Union Medical College Tianjin China
| | - Xue Fu
- State Key Laboratory of Experimental Hematology, National Clinical Research Center for Blood Diseases, Haihe Laboratory of Cell Ecosystem, Institute of Hematology & Blood Diseases Hospital Chinese Academy of Medical Sciences & Peking Union Medical College Tianjin China
| | - Yansong Ren
- State Key Laboratory of Experimental Hematology, National Clinical Research Center for Blood Diseases, Haihe Laboratory of Cell Ecosystem, Institute of Hematology & Blood Diseases Hospital Chinese Academy of Medical Sciences & Peking Union Medical College Tianjin China
| | - Yansheng Wang
- State Key Laboratory of Experimental Hematology, National Clinical Research Center for Blood Diseases, Haihe Laboratory of Cell Ecosystem, Institute of Hematology & Blood Diseases Hospital Chinese Academy of Medical Sciences & Peking Union Medical College Tianjin China
| | - Shoulei Wang
- State Key Laboratory of Experimental Hematology, National Clinical Research Center for Blood Diseases, Haihe Laboratory of Cell Ecosystem, Institute of Hematology & Blood Diseases Hospital Chinese Academy of Medical Sciences & Peking Union Medical College Tianjin China
| | - Gang An
- State Key Laboratory of Experimental Hematology, National Clinical Research Center for Blood Diseases, Haihe Laboratory of Cell Ecosystem, Institute of Hematology & Blood Diseases Hospital Chinese Academy of Medical Sciences & Peking Union Medical College Tianjin China
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16
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Kwapisz D. Serum free light chains in solid organ transplant recipients. Clin Transplant 2021; 35:e14286. [PMID: 33715217 DOI: 10.1111/ctr.14286] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2020] [Revised: 02/28/2021] [Accepted: 03/08/2021] [Indexed: 11/30/2022]
Abstract
Immunoglobulin is built by a pair of identical heavy and a pair of identical light chains. Light chains are produced in excess compared to heavy chains. Free light chains (FLCs) are those which are not combined with heavy chains. Currently, numerous assays are available for the measurement of serum FLCs (sFLCs). These assays cannot be used interchangeably, and renal function should be taken into account in interpreting test results. Levels of kappa and lambda sFLCs are usually used to diagnose and monitor plasma cell dyscrasias. However, the clinical relevance of sFLCs is being investigated in patients with a variety of diseases, including patients after transplantation. There are contradictory results regarding the usefulness of sFLCs in the prediction of post-transplant lymphoproliferative disorder (PTLD). However, it seems that sFLCs may be helpful in the prediction of early-onset PTLD. Some studies have shown that low levels of sFLCs are associated with a higher risk of infection in patients after transplantation. This review summarizes and highlights recent advances in the utility of sFLCs in the prediction of PTLD and infection, and inflammation assessment in patients after solid organ transplantation. Moreover, the influence of immunosuppressive treatment on sFLCs levels is described briefly.
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Affiliation(s)
- Dorota Kwapisz
- Department of Immunology, Transplantology and Internal Diseases, University Clinical Center of the Medical University of Warsaw, Warsaw, Poland
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17
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Morales-García LJ, Pacheco-Delgado MS. Serum free light chain reference intervals in an Optilite and their influence on clinical guidelines. Clin Biochem 2021; 92:54-60. [PMID: 33662349 DOI: 10.1016/j.clinbiochem.2021.02.008] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2020] [Revised: 01/26/2021] [Accepted: 02/16/2021] [Indexed: 11/17/2022]
Abstract
BACKGROUND Serum free light chain (FLC) analysis has been incorporated into the International Myeloma Working Group guidelines for the diagnosis and management of all monoclonal gammopathies. These recommendations were solely based on a single assay method (Freelite assay) and instrument. Here, we establish new reference intervals (RIs) for kappa and lambda FLC and the kappa-lambda difference and sum and a new diagnostic range for kappa/lambda FLC ratio (K/L-FLC) in an Optilite turbidimeter (The Binding Site) with the Freelite assay. METHODS To establish new RIs, the CLSI EP28-A3C protocol was applied to 249 sample blood donors from Fuenlabrada, Spain, and the central 95% and total range were estimated. Samples from patients with polyclonal hypo- and hypergammaglobulinemia were used for the evaluation of K/L-FLC as a monoclonal proliferation index. RESULTS The new RIs and the new K/L-FLC diagnostic range for the Optilite (0.65-2.56 mg/L) are very different from those in on the guidelines (0.26-1.65 mg/L). We propose new RIs for the K - L difference and the K + L sum. Diagnostic range validation as a monoclonal proliferation index with samples with hypo- and hypergammaglobulinemia confirms this new range. CONCLUSIONS In this study, we present the FLC RI for Freelite reagents measured on an Optilite turbidimeter. These ranges are different from those provided by the manufacturer and from those used in most studies in the literature, which may lead to patient misclassification. Manufacturers and clinical laboratories must strive to provide RIs for the technology they are using and for their population.
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Affiliation(s)
- Luis J Morales-García
- Department of Clinical Laboratory, Hospital Universitario de Fuenlabrada, Camino del Molino 2, Fuenlabrada, Madrid 28942, Spain.
| | - María S Pacheco-Delgado
- Department of Clinical Laboratory, Hospital Universitario de Fuenlabrada, Camino del Molino 2, Fuenlabrada, Madrid 28942, Spain.
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18
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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] [What about the content of this article? (0)] [Affiliation(s)] [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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19
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Bossuyt X, Poesen K, Sprangers B, Reynders M, Vercammen M, Delforge M. Determination of free light chains: assay-dependent differences in interpretation. Clin Chem Lab Med 2020; 59:e69-e71. [PMID: 32870806 DOI: 10.1515/cclm-2020-0938] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2020] [Accepted: 08/04/2020] [Indexed: 11/15/2022]
Affiliation(s)
- Xavier Bossuyt
- Department of Microbiology, Immunology and Transplantation, Clinical and Diagnostic Immunology, KU Leuven, Leuven, Belgium.,Department of Laboratory Medicine, University Hospitals Leuven, Leuven, Belgium
| | - Koen Poesen
- Laboratory Medicine, Immunology, University Hospitals Leuven, Leuven, Belgium.,Department of Neurosciences, Laboratory for molecular neurobiomarker research, KU Leuven, Leuven, Belgium
| | - Ben Sprangers
- Nephrology, University Hospitals Leuven, Leuven, Belgium
| | - Martin Reynders
- Laboratory Medicine, Immunology, University Hospitals Leuven, Leuven, Belgium
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20
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Schieferdecker A, Hörber S, Ums M, Besemer B, Bokemeyer C, Peter A, Weisel K. Comparison of three different serum-free light-chain assays-implications on diagnostic and therapeutic monitoring of multiple myeloma. Blood Cancer J 2020; 10:2. [PMID: 31915365 PMCID: PMC6949235 DOI: 10.1038/s41408-019-0267-8] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2019] [Revised: 11/19/2019] [Accepted: 11/25/2019] [Indexed: 11/09/2022] Open
Abstract
The measurement of serum-free light chains (FLC) is standard of care in the diagnosis and management of multiple myeloma (MM). The revised international myeloma working group (IMWG) implemented the involved FLC/noninvolved FLC (iFLC/niFLC) ratio as a biomarker for MM requiring treatment. Recently, a new definition of high-risk smoldering MM (SMM) including iFLC/niFLC ratio was published. These recommendations were solely based on a single assay method (Freelite assay). Today, two additional assays, N Latex FLC and ELISA-based Sebia FLC, are available. Here, we report on a single-center-study comparing results of all three different assays for FLC correlation and its potential implications for diagnostic and clinical use. In total, 187 samples from 47 MM patients were examined, and determination of FLC was performed. Comparison analyses showed similar FLC results for Sebia FLC and N Latex FLC assay with markedly lower absolute values for κ/λ ratio compared with Freelite. Values of λ FLC exhibited high variability. The ratio of iFLC/niFLC showed significant discrepancies among these assays. Our data demonstrate that the three available assays may result in markedly discrepant results, and should not be used interchangeably to monitor patients. Furthermore, modifications of the assay-specific diagnostic (iFLC/niFLC) thresholds for SMM and MM are recommended.
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Affiliation(s)
- Aneta Schieferdecker
- Department of Oncology and Hematology, BMT with Department of Pneumology, Hubertus Wald Tumorzentrum, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Sebastian Hörber
- Institute for Clinical Chemistry and Pathobiochemistry, Department for Diagnostic Laboratory Medicine, University Hospital Tuebingen, Tuebingen, Germany.,Institute for Diabetes Research and Metabolic Diseases of the Helmholtz Center Munich at the University of Tuebingen, Tuebingen, Germany.,German Center for Diabetes Research (DZD), München-Neuherberg, Germany
| | - Monika Ums
- Center of Clinical Trials (ZKS) Tübingen, University Hospital of Tuebingen, Tuebingen, Germany
| | - Britta Besemer
- Department of Hematology, Oncology, Immunology and Rheumatology, University Hospital of Tuebingen, Tuebingen, Germany
| | - Carsten Bokemeyer
- Department of Oncology and Hematology, BMT with Department of Pneumology, Hubertus Wald Tumorzentrum, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Andreas Peter
- Institute for Clinical Chemistry and Pathobiochemistry, Department for Diagnostic Laboratory Medicine, University Hospital Tuebingen, Tuebingen, Germany.,Institute for Diabetes Research and Metabolic Diseases of the Helmholtz Center Munich at the University of Tuebingen, Tuebingen, Germany.,German Center for Diabetes Research (DZD), München-Neuherberg, Germany
| | - Katja Weisel
- Department of Oncology and Hematology, BMT with Department of Pneumology, Hubertus Wald Tumorzentrum, University Medical Center Hamburg-Eppendorf, Hamburg, Germany. .,Department of Hematology, Oncology, Immunology and Rheumatology, University Hospital of Tuebingen, Tuebingen, Germany.
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21
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Ouyang D, Li Y, He W, Lin W, Hu L, Wang C, Xu L, Park J, You L. Mechanical segregation and capturing of clonal circulating plasma cells in multiple myeloma using micropillar-integrated microfluidic device. Biomicrofluidics 2019; 13:064114. [PMID: 31768200 PMCID: PMC6863761 DOI: 10.1063/1.5112050] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/04/2019] [Revised: 11/26/2019] [Accepted: 10/08/2019] [Indexed: 06/10/2023]
Abstract
Multiple myeloma (MM), the disorder of plasma cells, is the second most common type of hematological cancer and is responsible for approximately 20% of deaths from hematological malignancies. The current gold standard for MM diagnosis includes invasive bone marrow aspiration. However, it lacks the sensitivity to detect minimal residual disease, and the nonuniform distribution of clonal plasma cells (CPCs) within bone marrow also often results in inaccurate reporting. Serum and urine assessment of monoclonal proteins, such as Kappa light chains, is another commonly used approach for MM diagnosis. Although it is noninvasive, the level of paraprotein elevation is still too low for detecting minimal residual disease and nonsecretive MM. Circulating CPCs (cCPCs) have been reported to be present in the peripheral blood of MM patients, and high levels of cCPCs were shown to correlate with poor survival. This suggests a potential noninvasive approach for MM disease progress monitoring and prognosis. In this study, we developed a mechanical property-based microfluidic platform to capture cCPCs. Using human myeloma cancer cell lines spiked in healthy donor blood, the microfluidic platform demonstrates high enrichment ratio (>500) and sufficient capture efficiency (40%-55%). Patient samples were also assessed to investigate the diagnostic potential of cCPCs for MM by correlating with the levels of Kappa light chains in patients.
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Affiliation(s)
- Dongfang Ouyang
- Department of Mechanical and Industrial Engineering, University of Toronto, Toronto, Ontario M5S 3G8, Canada
| | - Yonghua Li
- Department of Hematology, General Hospital of Southern Theater Command, PLA, Guangzhou 510010, China
| | - Wenqi He
- Department of Biomedical Engineering, Southern University of Science and Technology, Shenzhen 518055, China
| | - Weicong Lin
- Department of Biomedical Engineering, Southern University of Science and Technology, Shenzhen 518055, China
| | - Lina Hu
- Department of Hematology, Shenzhen People's Hospital, Shenzhen 518020, China
| | - Chen Wang
- Pathology and Laboratory Medicine, Mount Sinai Hospital, Toronto, Ontario M5G 1X5, Canada
| | - Liangcheng Xu
- Institute of Biomaterials & Biomedical Engineering, University of Toronto, Toronto, Ontario M5S 3G9, Canada
| | - Jaewon Park
- Authors to whom correspondence should be addressed:, Tel.: +1 416-978-5736 and , Tel.: +86 755-8801-8574
| | - Lidan You
- Authors to whom correspondence should be addressed:, Tel.: +1 416-978-5736 and , Tel.: +86 755-8801-8574
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22
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Šegulja D, Matišić D, Barišić K, Rogić D. Verification study of free light chains assays on reagent-optimized analysers. Biochem Med (Zagreb) 2019; 29:030709. [PMID: 31624462 PMCID: PMC6784423 DOI: 10.11613/bm.2019.030709] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2019] [Accepted: 07/14/2019] [Indexed: 11/01/2022] Open
Abstract
Introduction: Our aim was to compare analytical specifications of two assays (monoclonal vs. polyclonal) for free light chains (FLCs) quantification optimized for two different analytical platforms, nephelometer ProSpec (Siemens, Erlangen, Germany) and turbidimetric analyser Optilite (The Binding Site, Birmingham, UK). Materials and methods: The evaluation included verification of the precision, repeatability and reproducibility, estimation of accuracy and method comparison study with 37 serum samples of haematological patients. Kappa and lambda FLC were measured in each sample by both methods and kappa/lambda ratio was calculated. Results: Results show satisfactory precision of both methods with coefficients of variation for ProSpec of CVwr = 2.20% and CVbr = 3.44%, and for Optilite CVwr = 2.82% and CVbr = 4.15%. Estimated bias for FLC lambda was higher on the ProSpec analyser, but bias for FLC kappa was higher on the Optilite analyser. Correlation coefficients were 0.98; P < 0.001 for FLC kappa and 0.97; P < 0.001 for FLC lambda. Considering normal/pathological FLC ratio moderate agreement within assays was detected (κ = 0.621). When the results were categorized according to criteria for progressive disease, 4/37 (0.10) cases were differently classified. Lambda FLC values by Optilite in three samples with monoclonal FLC lambda were more than twelve times higher than by ProSpec. A 25% difference in FLC ratio was detected in 16/37 (0.43) and 50% difference in 13/37 (0.35) patients. Conclusions: All manufacturers’ precision claims could not be achieved in the verification study. The comparison of results to biological variations data showed that coefficients of variations are acceptable for both assays. The assays should not be used interchangeably in haematological patients.
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Affiliation(s)
- Dragana Šegulja
- Department of Laboratory Diagnostics, University Hospital Centre Zagreb, Zagreb, Croatia
| | - Danica Matišić
- Department of Laboratory Diagnostics, University Hospital Centre Zagreb, Zagreb, Croatia
| | - Karmela Barišić
- Department of Medical Biochemistry and Hematology, Faculty of Pharmacy and Biochemistry, University of Zagreb, Zagreb, Croatia
| | - Dunja Rogić
- Department of Laboratory Diagnostics, University Hospital Centre Zagreb, Zagreb, Croatia
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Caponi L, Romiti N, Koni E, Fiore AD, Paolicchi A, Franzini M. Inter-assay variability in automated serum free light chain assays and their use in the clinical laboratory. Crit Rev Clin Lab Sci 2019; 57:73-85. [PMID: 31612753 DOI: 10.1080/10408363.2019.1670133] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Serum κ and λ free light chain levels are markers of plasma cell proliferation, and their measurements have been included in recent guidelines by the International Myeloma Working Group for the management of patients with plasma cellular dyscrasias. Five in vitro diagnostic methods for the immunochemical quantification of serum free light chains (FLC) are available, three based on polyclonal antibodies (Freelite®, The Binding Site; FLC ELISA κ and λ, Sebia; human κ and λ FLC, Diazyme Laboratories) and two on monoclonal antibodies (N Latex FLC, Siemens Healthineers; Seralite®, Sebia). Several studies have shown that these methods cannot be used interchangeably for the follow-up of patients because measured κ and λ FLC concentrations may differ significantly, especially at high levels. Because no international reference material for the measurement of FLC is available, it is not possible to establish which method is the most accurate. For this reason, knowledge about the analytical and diagnostic performances of the assays used is important. The aim of this review is to describe the main analytical features of the κ and λ FLC assays and how they may influence the clinical use of these parameters.
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Affiliation(s)
- Laura Caponi
- Department of Translational Research and New Technologies in Medicine, University of Pisa, Pisa, Italy
| | - Nadia Romiti
- Department of Translational Research and New Technologies in Medicine, University of Pisa, Pisa, Italy
| | - Elona Koni
- Department of Translational Research and New Technologies in Medicine, University of Pisa, Pisa, Italy
| | - Annarita Di Fiore
- Department of Translational Research and New Technologies in Medicine, University of Pisa, Pisa, Italy
| | - Aldo Paolicchi
- Department of Translational Research and New Technologies in Medicine, University of Pisa, Pisa, Italy
| | - Maria Franzini
- Department of Translational Research and New Technologies in Medicine, University of Pisa, Pisa, Italy
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Affiliation(s)
- Gurmukh Singh
- Department of Pathology, Medical College of Georgia at Augusta University, Augusta, Georgia
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