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Clinical Chemistry and Laboratory Medicine (CCLM)

Published in Association with the European Federation of Clinical Chemistry and Laboratory Medicine (EFLM)

Editor-in-Chief: Plebani, Mario

Ed. by Gillery, Philippe / Greaves, Ronda / Lackner, Karl J. / Lippi, Giuseppe / Melichar, Bohuslav / Payne, Deborah A. / Schlattmann, Peter

IMPACT FACTOR 2017: 3.556

CiteScore 2017: 2.34

SCImago Journal Rank (SJR) 2017: 1.114
Source Normalized Impact per Paper (SNIP) 2017: 1.188

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Volume 54, Issue 6


Analytical issues of serum free light chain assays and the relative performance of polyclonal and monoclonal based reagents

Hugh D. Carr-Smith / Ellen L. Jenner / Josie A.R. Evans / Stephen J. Harding
Published Online: 2016-03-04 | DOI: https://doi.org/10.1515/cclm-2015-1068


Serum free light chain (FLC) assays have been incorporated into routine clinical practice and their use is recommended in international guidelines for the management of monoclonal gammopathies. Given that FLCs are not simple analytes, laboratories should be aware of potential analytical issues when using FLC assays, including antigen excess, lot-to-lot variation and non-linearity. Whilst manufacturers of monoclonal antibody-based assays claim that they overcome such issues, the evidence available to date does not support this. Here we review and compare the technical performance of both polyclonal and monoclonal antibody-based assays. The evidence suggests that the Freelite assay, based on polyclonal antisera, gives a broader recognition of monoclonal FLCs than the N Latex assay, based on monoclonal antisera, and despite being cited as a technical concern, we show that lot-to-lot variation of the Freelite assay is good. Both non-linearity and antigen excess are characteristic of FLC analysis and laboratories should be aware of these phenomena regardless of the assay system they use. Comparisons of the absolute values of sFLCs determined using monoclonal and polyclonal antibody-based assays show poor quantitative agreement and, because current guidelines have been established using the polyclonal antibody-based Freelite assay, it should not be assumed that assays utilizing monoclonal antibodies will give compliance with these guidelines.

Keywords: antigen excess; Freelite; lot-to-lot variation; non-linearity; N latex


  • 1.

    Bradwell AR, Carr-Smith HD, Mead GP, Harvey TC, Drayson MT. Serum test for assessment of patients with Bence Jones myeloma. Lancet 2003;361:489–91.Google Scholar

  • 2.

    Drayson M, Tang LX, Drew R, Mead GP, Carr-Smith H, Bradwell AR. Serum free light-chain measurements for identifying and monitoring patients with nonsecretory multiple myeloma. Blood 2001;97:2900–2.Google Scholar

  • 3.

    Lachmann HJ, Gallimore R, Gillmore JD, Carr-Smith HD, Bradwell AR, Pepys MB, et al. Outcome in systemic AL amyloidosis in relation to changes in concentration of circulating free immunoglobulin light chains following chemotherapy. Br J Haematol 2003;122:78–84.Google Scholar

  • 4.

    Fuchida SI, Okano A, Hatsuse M, Murakami S, Haruyama H, Itoh S, et al. Serial measurement of free light chain detects poor response to therapy early in three patients with multiple myeloma who have measurable M-proteins. Int J Hematol 2012;96:664–8.Google Scholar

  • 5.

    Brioli A, Giles H, Pawlyn C, Campbell J, Kaiser M, Melchor L, et al. Serum free light chain evaluation as a marker for the impact of intra-clonal heterogeneity on the progression and treatment resistance in multiple myeloma. Blood 2014;123:3414–9.Google Scholar

  • 6.

    Hutchison CA, Plant T, Drayson M, Cockwell P, Kountouri M, Basnayake K, et al. Serum free light chain measurement aids the diagnosis of myeloma in patients with severe renal failure. BMC Nephrol 2008;9:11.Google Scholar

  • 7.

    Dispenzieri A, Kyle RA, Katzmann JA, Therneau TM, Larson D, Benson J, et al. Immunoglobulin free light chain ratio is an independent risk factor for progression of smoldering (asymptomatic) multiple myeloma. Blood 2008;111:785–9.Web of ScienceGoogle Scholar

  • 8.

    Rajkumar SV, Kyle RA, Therneau TM, Melton LJ, III, Bradwell AR, Clark RJ, et al. Serum free light chain ratio is an independent risk factor for progression in monoclonal gammopathy of undetermined significance. Blood 2005;106:812–7.Google Scholar

  • 9.

    Rajkumar SV, Dimopolous 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.Google Scholar

  • 10.

    Dispenzieri A, Kyle R, Merlini G, Miguel JS, Ludwig H, Hajek R, et al. International Myeloma Working Group guidelines for serum-free light chain analysis in multiple myeloma and related disorders. Leukemia 2009;23:215–24.Web of ScienceGoogle Scholar

  • 11.

    Tate JR, Mollee P, Dimeski G, Carter AC, Gill D. Analytical performance of serum free light-chain assay during monitoring of patients with monoclonal light-chain diseases. Clin Chim Acta 2007;376:30–6.Web of ScienceGoogle Scholar

  • 12.

    Murata K, Clark RJ, Lockington KS, Tostrud LJ, Greipp PR, Katzmann JA. Sharply increased serum free light-chain concentrations after treatment for multiple myeloma. Clin Chem 2010;56:16–8.Google Scholar

  • 13.

    Bradwell AR, Carr-Smith HD, Mead GP, Tang LX, Showell PJ, Drayson MT, et al. Highly sensitive, automated immunoassay for immunoglobulin free light chains in serum and urine. Clin Chem 2001;47:673–80.Google Scholar

  • 14.

    Cavalcanti E, Barchiesi V, Cuomo M, Di Paola F, Morabito F, Cavalcanti S. A particular case of lambda chain multiple myeloma. Biochimica Clinica 2013;37:428–30.Google Scholar

  • 15.

    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.Google Scholar

  • 16.

    Lock R, Saleem R, Roberts E, Wallage M, Pesce T, Rowbottom A, et al. A multicentre study comparing two methods for serum free light chain analysis. Ann Clin Biochem 2013;50:255–61.Google Scholar

  • 17.

    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(Pt 5):450–5.Web of ScienceGoogle Scholar

  • 18.

    Schneider N, Wynckel A, Kolb B, Sablon E, Gillery P, Maquart FX. [Comparative analysis of immunoglobulin free light chains quantification by Freelite (The Binding Site) and N Latex FLC (Siemens) methods]. Ann Biol Clin (Paris) 2013;71:13–9.Web of ScienceGoogle Scholar

  • 19.

    Kubicki T, Dytfeld D, Baszczuk A, Lewandowski K, Komarnicki M. Polyclonal based serum free light chains assessment better than monoclonal based test characterizes disease activity in patients with multiple myeloma. Presented at Lymphoma and Myeloma 2015;P5a.Google Scholar

  • 20.

    van Velzen JF, van den Blink D, Bloem AC. Inability of a monoclonal anti-light chain antibody to detect clonal plasma cells in a patient with multiple myeloma by multicolor flow cytometry. Cytometry B Clin Cytom 2013;84:30–2.Google Scholar

  • 21.

    Jacobs JF, Hoedemakers RM, Teunissen E, van der Molen RG, Te VH. Effect of sample dilution on two free light chain nephelometric assays. Clin Chim Acta 2012;413:1708–9.Google Scholar

  • 22.

    Sharrod-Cole H, Matters D, Showell P, Harding S. Serum free light chain assessments: Comparison of precision and linearity. Biochmica Clinica 2013;37(SS):T390a.Google Scholar

  • 23.

    Bosmann M, Kossler J, Stolz H, Walter U, Knop S, Steigerwald U. Detection of serum free light chains: the problem with antigen excess. Clin Chem Lab Med 2010;48:1419–22.Google Scholar

  • 24.

    Vercammen M, Meirlaen P, Broodtaerts L, Broek IV, Bossuyt X. Effect of sample dilution on serum free light chain concentration by immunonephelometric assay. Clin Chim Acta 2011;412: 1798–804.Web of ScienceGoogle Scholar

  • 25.

    Burden JM, Matters DJ, Carr-Smith HD, Young P, Harding SJ. Comparison of Freelite and N Latex FLC utilising diagnostically relevant samples. Clin Chem 2012;58(Suppl 10):C44a.Google Scholar

  • 26.

    Harding SJ, Popat R, Berlanga O, Sharrod H, Cavenagh J, Oakervee H. Comparison of the analytical performance of polyclonal and monoclonal antibody based FLC assays in refractory multiple myeloma patients. Clin Chem 2013;59 (Suppl 10):A22a.Google Scholar

  • 27.

    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.Web of ScienceGoogle Scholar

  • 28.

    Leung N, Gertz MA, Zeldenrust SR, Rajkumar SV, Dispenzieri A, Fervenza FC, et al. Improvement of cast nephropathy with plasma exchange depends on the diagnosis and on reduction of serum free light chains. Kidney Int 2008;73:1282–8.Web of ScienceGoogle Scholar

  • 29.

    Hutchison CA, Cockwell P, Cook M. Diagnostic accuracy of monoclonal antibody based serum immunoglobulin free light chain immunoassays in myeloma cast nephropathy. BMC Clin Pathol 2012;12:12.Google Scholar

  • 30.

    Hutchison CA, Harding S, Hewins P, Mead GP, Townsend J, Bradwell AR, et al. Quantitative assessment of serum and urinary polyclonal free light chains in patients with chronic kidney disease. Clin J Am Soc Nephrol 2008;3:1684–90.Google Scholar

  • 31.

    Jacobs JF, Hoedemakers RM, Teunissen E, Te VH. N Latex FLC serum free light-chain assays in patients with renal impairment. Clin Chem Lab Med 2014;52:853–9.Web of ScienceGoogle Scholar

  • 32.

    Tate J, Bazeley S, Klingberg S, Pretorius CJ, Hawley C, Mollee P. Comparison of the Freelite and N Latex serum free light chain (FLC) assays in chronic kidney disease. Clin Biochem Rev 2012;33(Supplement):P53a.Google Scholar

About the article

Corresponding author: Hugh D. Carr-Smith, The Binding Site Ltd., Birmingham, B15 1QT, UK

Received: 2015-11-02

Accepted: 2016-01-21

Published Online: 2016-03-04

Published in Print: 2016-06-01

Citation Information: Clinical Chemistry and Laboratory Medicine (CCLM), Volume 54, Issue 6, Pages 997–1003, ISSN (Online) 1437-4331, ISSN (Print) 1434-6621, DOI: https://doi.org/10.1515/cclm-2015-1068.

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