Different immunoreactivity of monomers and dimers makes automated free light chains assays not equivalent
-
Laura Caponi
,
Elona Koni
Abstract
Background
The automated immunochemical serum free light chains (FLC) assays, Freelite (a polyclonal antiserum) and N Latex FLC (a mixture of monoclonal antibodies), are not interchangeable, as they may provide different results on a same sample. This study was aimed to establish if the calibrators contain FLC oligomers, and if different reactivity against monomers and dimers contributes to the discrepancy.
Methods
Gel filtration chromatography fractions of the calibrators were subjected to a Western blot (WB) and analyzed by each reagent. The procedure was repeated after pretreating the N Latex FLC calibrator with the reducing agent dithiothreitol (DTT).
Results
Both calibrators contain FLC dimers and monomers. Both reagents detect (with different sensitivity) FLC kappa monomers and dimers; instead, Freelite detects only FLC lambda dimers, while N Latex FLC detects only FLC monomers. After DTT treatment, only the N Latex lambda still detects FLC with reduced protein thiols, while the reactivity of all other reagents is abolished.
Conclusions
Due to their different reactivity against FLC monomers and oligomers, the Freelite and N Latex FLC are calibrated against different components of their own calibrators, making the two reagents not equivalent. The redox status of FLC determines the immunoreactivity not only of FLC dimers, but also of the monomers.
Author contributions: All the authors have accepted responsibility for the entire content of this submitted manuscript and approved submission.
Research funding: Institutional funding of University of Pisa.
Employment or leadership: None declared.
Honorarium: None declared.
Competing interests: The funding organization played no role in the study design; in the collection, analysis, and interpretation of data; in the writing of the report; or in the decision to submit the report for publication.
References
1. Rajkumar SV, Dimopoulos MA, Palumbo A, Blade J, Merlini G, Mateos MV, et al. International Myeloma Working Group updated criteria for the diagnosis of multiple myeloma. Lancet Oncol 2014;15:e538–48.10.1016/S1470-2045(14)70442-5Suche in Google Scholar PubMed
2. Graziani MS, Merlini G. Serum free light chain analysis in the diagnosis and management of multiple myeloma and related conditions. Expert Rev Mol Diagn 2014;14:55–66.10.1586/14737159.2014.864557Suche in Google Scholar PubMed
3. Jenner E. Serum free light chains in clinical laboratory diagnostics. Clin Chim Acta 2014;427:15–20.10.1016/j.cca.2013.08.018Suche in Google Scholar PubMed
4. Mollee P, Tate J, Pretorius CJ. Evaluation of the N Latex free light chain assay in the diagnosis and monitoring of AL amyloidosis. Clin Chem Lab Med 2013;51:2303–10.10.1515/cclm-2013-0361Suche in Google Scholar PubMed
5. Kim HS, Kim HS, Shin KS, Song W, Kim HJ, Kim HS, et al. Clinical comparisons of two free light chain assays to immunofixation electrophoresis for detecting monoclonal gammopathy. Biomed Res Int 2014;647238:1–7.10.1155/2014/647238Suche in Google Scholar PubMed PubMed Central
6. Carr-Smith HD, Jenner EL, Evans JA, Harding SJ. Analytical issues of serum free light chain assays and the relative performance of polyclonal and monoclonal based reagents. Clin Chem Lab Med 2016;54:997–1003.10.1515/cclm-2015-1068Suche in Google Scholar PubMed
7. Caponi L, Franzini M, Koni E, Masotti S, Petrini M, Paolicchi A. Discrepancy between FLC assays: only a problem of quantification? Clin Chem Lab Med 2016;54:1111–3.10.1515/cclm-2015-1262Suche in Google Scholar PubMed
8. Bossuyt X, Delforge M, Reynders M, Dillaerts D, Sprangers B, Fostier K, et al. Diagnostic thresholds for free light chains in multiple myeloma depend on the assay used. Leukemia 2017. doi: 10.1038/leu.2017.335. [Epub ahead of print].10.1038/leu.2017.335Suche in Google Scholar PubMed
9. Di Noto G, Cimpoies E, Dossi A, Paolini L, Radeghieri A, Caimi L, et al. Polyclonal versus monoclonal immunoglobulin-free light chains quantification. Ann Clin Biochem 2015;52:327–36.10.1177/0004563214553808Suche in Google Scholar PubMed
10. Kaplan B, Ramirez-Alvarado M, Sikkink L, Golderman S, Dispenzieri A, Livneh A, et al. Free light chains in plasma of patients with light chain amyloidosis and non-amyloid light chain deposition disease. High proportion and heterogeneity of disulfide-linked monoclonal free light chains as pathogenic features of amyloid disease. Br J Haematol 2009;144:705–15.10.1111/j.1365-2141.2008.07522.xSuche in Google Scholar PubMed
11. Kaplan B, Golderman S, Aizenbud B, Esev K, Kukuy O, Leiba M, et al. Immunoglobulin-free light chain monomer-dimer patterns help to distinguish malignant from premalignant monoclonal gammopathies: a pilot study. Am J Hematol 2014;89:882–8.10.1002/ajh.23773Suche in Google Scholar PubMed
12. te Velthuis H, Knop I, Stam P, van den Broek M, Bos HK, Hol S, et al. N Latex FLC – new monoclonal high-performance assays for the determination of free light chain kappa and lambda. Clin Chem Lab Med 2011;49:1323–32.10.1515/CCLM.2011.624Suche in Google Scholar PubMed
13. Baden EM, Owen BA, Peterson FC, Volkman BF, Ramirez-Alvarado M, Thompson JR. Altered dimer interface decreases stability in an amyloidogenic protein. J Biol Chem 2008;283:15853–60.10.1074/jbc.M705347200Suche in Google Scholar PubMed PubMed Central
14. Palladini G, Jaccard A, Milani P, Lavergne D, Foli A, Bender S, et al. Circulating free light chain measurement in the diagnosis, prognostic assessment and evaluation of response of AL amyloidosis: comparison of Freelite and N latex FLC assays. Clin Chem Lab Med 2017;55:1734–43.10.1515/cclm-2016-1024Suche in Google Scholar PubMed
15. Pretorius CJ, Klingberg S, Tate J, Wilgen U, Ungerer JP. Evaluation of the N Latex FLC free light chain assay on the Siemens BN analyser: precision, agreement, linearity and variation between reagent lots. Ann Clin Biochem 2012;49:450–5.10.1258/acb.2012.011264Suche in Google Scholar PubMed
16. Hoedemakers RM, Pruijt JF, Hol S, Teunissen E, Martens H, Stam P, et al. Clinical comparison of new monoclonal antibody-based nephelometric assays for free light chain kappa and lambda to polyclonal antibody-based assays and immunofixation electrophoresis. Clin Chem Lab Med 2011;50:489–95.10.1515/cclm.2011.793Suche in Google Scholar PubMed
17. Lock RJ, Saleem R, Roberts EG, Wallage MJ, Pesce TJ, Rowbottom A, et al. A multicentre study comparing two methods for serum free light chain analysis. Ann Clin Biochem 2013;50:255–61.10.1177/0004563212473447Suche in Google Scholar PubMed
18. Messiaen AS, De Sloovere MM, Claus PE, Vercammen M, Van Hoovels L, Heylen O, et al. Performance evaluation of serum free light chain analysis: nephelometry vs turbidimetry, monoclonal vs polyclonal reagents. Am J Clin Pathol 2017;147:611–22.10.1093/ajcp/aqx037Suche in Google Scholar PubMed
19. Palumbo A, Rajkumar SV, San Miguel JF, Larocca A, Niesvizky R, Morgan G, et al. International Myeloma Working Group consensus statement for the management, treatment, and supportive care of patients with myeloma not eligible for standard autologous stem-cell transplantation. J Clin Oncol 2014;32:587–600.10.1200/JCO.2013.48.7934Suche in Google Scholar PubMed PubMed Central
©2019 Walter de Gruyter GmbH, Berlin/Boston
Artikel in diesem Heft
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Artikel in diesem Heft
- Frontmatter
- Obituary
- Jillian Russyll (AKA Jill) Tate
- Editorial
- The long way to standardization of practices: HbA1c as archetypal example
- Reviews
- Secretory tumors of the pituitary gland: a clinical biochemistry perspective
- Thalassemia in the laboratory: pearls, pitfalls, and promises
- Opinion Paper
- Diagnostic biomarkers of muscle injury and exertional rhabdomyolysis
- General Clinical Chemistry and Laboratory Medicine
- Patient’s knowledge and awareness about the effect of the over-the-counter (OTC) drugs and dietary supplements on laboratory test results: a survey in 18 European countries
- National surveys on 15 quality indicators for the total testing process in clinical laboratories of China from 2015 to 2017
- Urinary albumin strip assay as a screening test to replace quantitative technology in certain conditions
- Cerebrospinal fluid free kappa light chains and kappa index perform equal to oligoclonal bands in the diagnosis of multiple sclerosis
- Different immunoreactivity of monomers and dimers makes automated free light chains assays not equivalent
- The utility of saliva testing in the estimation of uremic toxin levels in serum
- Determination of cannabinoids in oral fluid and urine of “light cannabis” consumers: a pilot study
- Moving from the second to the third generation Roche PTH assays: what are the consequences for clinical practice?
- Baseline hepcidin measurement in the differential diagnosis of anaemia for elderly patients and its correlation with the increment of transferrin saturation following an oral iron absorption test
- Reference Values and Biological Variations
- A multicenter study for the evaluation of the reference interval for TSH in Italy (ELAS TSH Italian Study)
- Cancer Diagnostics
- Urinary measurement of circulating tumor DNA for treatment monitoring and prognosis of metastatic colorectal cancer patients
- BCL2L12: a multiply spliced gene with independent prognostic significance in breast cancer
- Diabetes
- The global impact of the International Federation of Clinical Chemistry and Laboratory Medicine, Education and Management Division: engaging stakeholders and assessing HbA1c quality in a multicentre study across China
- The frequency of testing for glycated haemoglobin, HbA1c, is linked to the probability of achieving target levels in patients with suboptimally controlled diabetes mellitus
- Letters to the Editor
- Response to article by Caponi et al. about serum free light chains
- Response to Letter to the Editor about immunochemical measurement of urine free light chains
- Estimated GFR-specific 99th percentiles for high-sensitive cardiac troponin T based on the adjusted analytical change limit (adjACL) in hospitalized patients
- Perioperative heart-type fatty acid binding protein concentration cutoffs for the identification of severe acute kidney injury in patients undergoing cardiac surgery
- A peculiar reaction curve with dual spikes in absorbance during a total bilirubin assay in spite of accurate results induced by high M-protein concentration
- Extremely low high-density-lipoprotein cholesterol due to an unusual non-inherited cause: a case report
- A single-center performance evaluation of the fully automated iFlash anti-Müllerian hormone immunoassay
- Genetic polymorphisms and variants in the LDL receptor associated with familial hypercholesterolemia: cascade screening and identification of the variants 666C>A, 862G>A, 901G>A, and 919G>A of a Brazilian family
- Undetected paraganglioma by functional imaging techniques: case report
- A particular case of AML patient with the polymorphism G105G (rs11554137) and the missense mutation R132C in IDH1 gene
- Atypical “hairy cell-like” presentation of leukemic mantle cell lymphoma
- Evaluation of a rapid centrifugation step (4500 g for 2 min) in coagulation assays to monitor direct oral anticoagulants
