Home Direct screening and quantification of monoclonal immunoglobulins in serum using MALDI-TOF mass spectrometry without antibody enrichment
Article
Licensed
Unlicensed Requires Authentication

Direct screening and quantification of monoclonal immunoglobulins in serum using MALDI-TOF mass spectrometry without antibody enrichment

  • Hou-Long Luo , Peng Ye , Yuxi Wang , Huan Ding , Beiqi Cao , Shangying Wu , Hui Yu , Rong He , Liansheng Wang , Yueying Huang , Anping Xu ORCID logo EMAIL logo and Ling Ji EMAIL logo
Published/Copyright: April 18, 2025
Become an author with De Gruyter Brill
Submit Manuscript Author Information
Clinical Chemistry and Laboratory Medicine (CCLM)
From the journal Clinical Chemistry and Laboratory Medicine (CCLM) Volume 63 Issue 9

Abstract

Objectives

Monoclonal gammopathies (MGs) are characterized by the presence of monoclonal immunoglobulins (M-proteins). Currently, recommendations for screening of MGs primarily rely on nephelometry, turbidimetry and electrophoresis, which have inherent limitations in sensitivity and throughput. This study aimed to evaluate a novel MALDI-TOF MS-based method, the intact M-protein Screening-Light Chain Assay (iMS-LC Assay), for direct M-protein detection and quantification without antibody enrichment.

Methods

Residual serum samples previously analyzed via serum protein electrophoresis (SPE) and immunofixation electrophoresis (IFE) were reduced to dissociate light chains from heavy chains. MALDI-TOF MS was then performed to determine the presence of M-protein characteristic pattern. The iMS-LC Assay’s analytical sensitivity, specificity, and screening efficacy in healthy populations were assessed.

Results

The iMS-LC Assay successfully detected all M-proteins identified by SPE and demonstrated higher sensitivity in analytical and diagnostic studies. It accurately quantified M-proteins at concentrations below 10 g/L, with a detection limit of 0.2 g/L and the ability to detect levels below 0.1 g/L. For samples with M-protein concentrations >1 g/L, intra-assay and inter-assay coefficients of variation were <10 %. In prospective screening of M-proteins in the healthy population, the iMS-LC Assay detected M-proteins at a prevalence of 3.15 %, higher than IFE (1.87 %) and SPE (0.94 %).

Conclusions

The iMS-LC Assay shows potential to replace SPE and drive advancements in the screening, diagnosis, and monitoring of MGs. Further validation of its clinical sensitivity and specificity is essential to determine its adequacy as a routine screening tool for M-proteins.

Keywords: monoclonal gammopathies; M-protein; MALDI-TOF mass spectrometry; screening; quantification
Corresponding authors: Anping Xu and Ling Ji, Department of Laboratory Medicine, Peking University Shenzhen Hospital, 1120 Lianhua Road Futian, Shenzhen, Guangdong, 518036, P.R. China, E-mail: (A. Xu), (L. Ji).
Hou-Long Luo and Peng Ye contributed equally to this work.

Funding source: Shenzhen Science and Technology Program

Award Identifier / Grant number: JCYJ20230807095115029

Award Identifier / Grant number: JCYJ20240813120000002

Funding source: Zhongnanshan Medical Foundation of Guandong Province

Award Identifier / Grant number: ZNSXS-20240108

Funding source: The Research Foundation of Peking University Shenzhen Hospital

Award Identifier / Grant number: JCYJ2021008

  1. Research ethics: Research involving human subjects complied with all relevant national regulations, institutional policies and is in accordance with the Helsinki Declaration, and has been approved by the Medical Ethical Committee of Peking University Shenzhen Hospital, Shenzhen, China.

  2. Informed consent: Informed consent was obtained from all individuals included in this study, or their legal guardians or wards.

  3. Author contributions: All authors have accepted responsibility for the entire content of this manuscript and approved its submission.

  4. Use of Large Language Models, AI and Machine Learning Tools: None declared.

  5. Conflict of interest: The authors state no conflict of interest.

  6. Research funding: This work was supported by the Research Foundation of Peking University Shenzhen Hospital [grant numbers JCYJ2021008], Zhongnanshan Medical Foundation of Guandong Province [grant numbers ZNSXS-20240108] and Shenzhen Science and Technology Program [grant numbers JCYJ20240813120000002 and JCYJ20230807095115029].

  7. Data availability: The raw data can be obtained on request from the corresponding author.

References

1. Cárdenas, MC, García-Sanz, R, Puig, N, Pérez-Surribas, D, Flores-Montero, J, Ortiz-Espejo, M, et al.. Recommendations for the study of monoclonal gammopathies in the clinical laboratory. A consensus of the Spanish Society of Laboratory Medicine and the Spanish Society of Hematology and Hemotherapy. Part I: update on laboratory tests for the study of monoclonal gammopathies. Clin Chem Lab Med 2023;61:2115–30. https://doi.org/10.1515/cclm-2023-0326.Search in Google Scholar PubMed

2. Wang, W, Li, J, Yang, Y, Chen, F, Xu, T, Wang, P, et al.. Update on the outcome of M-protein screening program of multiple myeloma in China: a 7-year cohort study. Cancer Med 2024;13:e6859. https://doi.org/10.1002/cam4.6859.Search in Google Scholar PubMed PubMed Central

3. Sanchorawala, V. Systemic light chain amyloidosis. N Engl J Med 2024;390:2295–307. https://doi.org/10.1056/nejmra2304088.Search in Google Scholar

4. Rajkumar, SV. Multiple myeloma: 2024 update on diagnosis, risk-stratification, and management. Am J Hematol 2024;99:1802–24. https://doi.org/10.1002/ajh.27422.Search in Google Scholar PubMed PubMed Central

5. Ting, HY, Sthaneshwar, P, Bee, PC, Shanmugam, H, Lim, M. Heavy/light chain assay in the monitoring of multiple myeloma. Pathology 2019;51:507–11. https://doi.org/10.1016/j.pathol.2019.04.002.Search in Google Scholar PubMed

6. Clavijo, A, Ryan, N, Xu, H, Singh, G. Measurement of monoclonal immunoglobulin protein concentration in serum protein electrophoresis: comparison of automated vs manual/human readings. Lab Med 2020;51:252–8. https://doi.org/10.1093/labmed/lmz055.Search in Google Scholar PubMed

7. Salamatmanesh, M, McCudden, CR, McCurdy, A, Booth, RA. Monoclonal protein reference change value as determined by gel-based serum protein electrophoresis. Clin Biochem 2018;51:61–5. https://doi.org/10.1016/j.clinbiochem.2017.10.006.Search in Google Scholar PubMed

8. Smith, J, Raines, G, Schneider, HG. A comparison between high resolution serum protein electrophoresis and screening immunofixation for the detection of monoclonal gammopathies in serum. Clin Chem Lab Med 2018;56:256–63. https://doi.org/10.1515/cclm-2017-0266.Search in Google Scholar PubMed

9. 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 2023;62:929–38. https://doi.org/10.1515/cclm-2023-0912.Search in Google Scholar PubMed

10. Guan, L, Su, W, Zhong, J, Qiu, L. M-protein detection by mass spectrometry for minimal residual disease in multiple myeloma. Clin Chim Acta 2024;552:117623. https://doi.org/10.1016/j.cca.2023.117623.Search in Google Scholar PubMed

11. Keren, DF, Bocsi, G, Billman, BL, Etzell, J, Faix, JD, Kumar, S, et al.. Laboratory detection and initial diagnosis of monoclonal gammopathies. Arch Pathol Lab Med 2022;146:575–90. https://doi.org/10.5858/arpa.2020-0794-cp.Search in Google Scholar

12. Katzmann, JA, Willrich, MA, Kohlhagen, MC, Kyle, RA, Murray, DL, Snyder, MR, et al.. Monitoring IgA multiple myeloma: immunoglobulin heavy/light chain assays. Clin Chem 2015;61:360–7. https://doi.org/10.1373/clinchem.2014.231985.Search in Google Scholar PubMed

13. Murray, DL, Ryu, E, Snyder, MR, Katzmann, JA. Quantitation of serum monoclonal proteins: relationship between agarose gel electrophoresis and immunonephelometry. Clin Chem 2009;55:1523–9. https://doi.org/10.1373/clinchem.2009.124461.Search in Google Scholar PubMed

14. Caillon, H, Dejoie, T, LeLoupp, AG, Azoulay-Fauconnier, C, Masson, D, Moreau, P, et al.. Difficulties in immunofixation analysis: a concordance study on the IFM 2007-02 trial. Blood Cancer J 2013;3:e154. https://doi.org/10.1038/bcj.2013.51.Search in Google Scholar PubMed PubMed Central

15. Fernandez de Larrea, C, Tovar, N, Cibeira, MT, Arostegui, JI, Rosinol, L, Elena, M, et al.. Emergence of oligoclonal bands in patients with multiple myeloma in complete remission after induction chemotherapy: association with the use of novel agents. Haematologica 2011;96:171–3. https://doi.org/10.3324/haematol.2010.030882.Search in Google Scholar PubMed PubMed Central

16. Willrich, MA, Ladwig, PM, Andreguetto, BD, Barnidge, DR, Murray, DL, Katzmann, JA, et al.. Monoclonal antibody therapeutics as potential interferences on protein electrophoresis and immunofixation. Clin Chem Lab Med 2016;54:1085–93. https://doi.org/10.1515/cclm-2015-1023.Search in Google Scholar PubMed

17. Dimopoulos, MA, Dytfeld, D, Grosicki, S, Moreau, P, Takezako, N, Hori, M, et al.. Elotuzumab plus pomalidomide and dexamethasone for relapsed/refractory multiple myeloma: final overall survival analysis from the randomized phase II ELOQUENT-3 trial. J Clin Oncol 2023;41:568–78. https://doi.org/10.1200/jco.21.02815.Search in Google Scholar

18. Botz, CM, Barnidge, DR, Murray, DL, Katzmann, JA. Detecting monoclonal light chains in urine: microLC-ESIQ-TOF mass spectrometry compared to immunofixation electrophoresis. Br J Haematol 2014;167:437–8. https://doi.org/10.1111/bjh.13003.Search in Google Scholar PubMed

19. Barnidge, DR, Dasari, S, Botz, CM, Murray, DH, Snyder, MR, Katzmann, JA, et al.. Using mass spectrometry to monitor monoclonal immunoglobulins in patients with a monoclonal gammopathy. J Proteome Res 2014;13:1419–27. https://doi.org/10.1021/pr400985k.Search in Google Scholar PubMed

20. Mills, JR, Barnidge, DR, Murray, DL. Detecting monoclonal immunoglobulins in human serum using mass spectrometry. Methods 2015;81:56–65. https://doi.org/10.1016/j.ymeth.2015.04.020.Search in Google Scholar PubMed

21. Barnidge, DR, Kirck, TP, Griffin, TJ, Murray, DL. Using matrix-assisted laser desorption/ionization time-offlight mass spectrometry to detect monoclonal immunoglobuli light chains in serum and urine. Rapid Commun Mass Spectrom 2015;29:2057–60.10.1002/rcm.7314Search in Google Scholar PubMed

22. Kohlhagen, MC, Barnidge, DR, Mills, JR, Stoner, J, Gurtner, KM, Liptac, AM, et al.. Screening method for m-proteins in serum using nanobody enrichment coupled to MALDI-TOF mass spectrometry. Clin Chem 2016;62:1345–52. https://doi.org/10.1373/clinchem.2015.253781.Search in Google Scholar PubMed

23. Mills, JR, Kohlhagen, MC, Dasari, S, Vanderboom, PM, Kyle, RA, Katzmann, JA, et al.. Comprehensive assessment of m-proteins using nanobody enrichment coupled to MALDI-TOF mass spectrometry. Clin Chem 2016;62:1334–44. https://doi.org/10.1373/clinchem.2015.253740.Search in Google Scholar PubMed

24. Zajec, M, Langerhorst, P, VanDuijn, MM, Gloerich, J, Russcher, H, van Gool, AJ, et al.. Mass spectrometry for identification, monitoring, and minimal residual disease detection of m-proteins. Clin Chem 2020;66:421–33. https://doi.org/10.1093/clinchem/hvz041.Search in Google Scholar PubMed

25. Zajec, M, Jacobs, JFM, de Kat Angelino, CM, Dekker, LJM, Stingl, C, Luider, TM, et al.. Integrating serum protein electrophoresis with mass spectrometry, a new workflow for m-protein detection and quantification. J Proteome Res 2020;19:2845–53. https://doi.org/10.1021/acs.jproteome.9b00705.Search in Google Scholar PubMed

26. Murray, DL, Puig, N, Kristinsson, S, Usmani, SZ, Dispenzieri, A, Bianchi, G, et al.. Mass spectrometry for the evaluation of monoclonal proteins in multiple myeloma and related disorders: an international myeloma working group mass spectrometry committee report. Blood Cancer J 2021;11:24. https://doi.org/10.1038/s41408-021-00408-4.Search in Google Scholar PubMed PubMed Central

27. Katzmann, JA, Clark, RJ, Abraham, RS, Bryant, S, Lymp, JF, Bradwell, AR, et al.. Serum reference intervals and diagnostic ranges for free kappa and free lambda immunoglobulin light chains: relative sensitivity for detection of monoclonal light chains. Clin Chem 2002;48:1437–44. https://doi.org/10.1093/clinchem/48.9.1437.Search in Google Scholar

28. 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. https://doi.org/10.2215/cjn.02290508.Search in Google Scholar PubMed PubMed Central

29. McCudden, CR, Mathews, SP, Hainsworth, SA, Chapman, JF, Hammett-Stabler, CA, Willis, MS, et al.. Performance comparison of capillary and agarose gel electrophoresis for the identification and characterization of monoclonal immunoglobulins. Am J Clin Pathol 2008;129:451–8. https://doi.org/10.1309/6kt8n49brnvvvbt1.Search in Google Scholar

30. Poisson, J, Fedoriw, Y, Henderson, MP, Hainsworth, S, Tucker, K, Uddin, Z, et al.. Performance evaluation of the Helena V8 capillary electrophoresis system. Clin Biochem 2012;45:697–9. https://doi.org/10.1016/j.clinbiochem.2012.03.018.Search in Google Scholar PubMed

31. Kohlhagen, M, Dasari, S, Willrich, M, Hetrick, M, Netzel, B, Dispenzieri, A, et al.. Automation and validation of a MALDI-TOF MS (Mass-Fix) replacement of immunofixation electrophoresis in the clinical lab. Clin Chem Lab Med 2020;59:155–63. https://doi.org/10.1515/cclm-2020-0581.Search in Google Scholar PubMed

32. Li, J, Xu, A, Xie, W, Li, B, Yan, C, Xia, Y, et al.. MALDI-TOF-MS for rapid screening analysis of M-protein in serum. Front Oncol 2022;12:1073479. https://doi.org/10.3389/fonc.2022.1073479.Search in Google Scholar PubMed PubMed Central

33. Katzmann, JA, Stankowski-Drengler, TJ, Kyle, RA, Karen, SL, Snyder, MR, Lust, JA, et al.. Specificity of serum and urine protein electrophoresis for the diagnosis of monoclonal gammopathies. Clin Chem. 2010;56:1899–900. https://doi.org/10.1373/clinchem.2010.152280.Search in Google Scholar PubMed

34. Murray, D, Kumar, SK, Kyle, RA, Dispenzieri, A, Dasari, S, Larson, DR, et al.. Detection and prevalence of monoclonal gammopathy of undetermined significance: a study utilizing mass spectrometry-based monoclonal immunoglobulin rapid accurate mass measurement. Blood Cancer J 2019;9:102. https://doi.org/10.1038/s41408-019-0263-z.Search in Google Scholar PubMed PubMed Central

35. Vachon, CM, Murray, J, Allmer, C, Larson, D, Norman, AD, Sinnwell, JP, et al.. Prevalence of heavy chain MGUS by race and family history risk groups using a high-sensitivity screening method. Blood Adv 2022;6:3746–50. https://doi.org/10.1182/bloodadvances.2021006201.Search in Google Scholar PubMed PubMed Central

36. El-Khoury, H, Lee, DJ, Alberge, JB, Redd, R, Cea-Curry, CJ, Perry, J, et al.. Prevalence of monoclonal gammopathies and clinical outcomes in a high-risk US population screened by mass spectrometry: a multicentre cohort study. Lancet Haematol 2022;9:e340–9. https://doi.org/10.1016/s2352-3026(22)00069-2.Search in Google Scholar PubMed PubMed Central

Supplementary Material

This article contains supplementary material (https://doi.org/10.1515/cclm-2025-0203).

Received: 2025-02-20
Accepted: 2025-04-08
Published Online: 2025-04-18
Published in Print: 2025-08-26

© 2025 Walter de Gruyter GmbH, Berlin/Boston

Articles in the same Issue

  1. Frontmatter
  2. Editorial
  3. Macroprolactinaemia – some progress but still an ongoing problem
  4. Review
  5. Understanding the circulating forms of cardiac troponin: insights for clinical practice
  6. Opinion Papers
  7. New insights in preanalytical quality
  8. IFCC recommendations for internal quality control practice: a missed opportunity
  9. Genetics and Molecular Diagnostics
  10. Evaluation of error detection and treatment recommendations in nucleic acid test reports using ChatGPT models
  11. General Clinical Chemistry and Laboratory Medicine
  12. Pre-analytical phase errors constitute the vast majority of errors in clinical laboratory testing
  13. Improving the efficiency of quality control in clinical laboratory with an integrated PBRTQC system based on patient risk
  14. IgA-type macroprolactin among 130 patients with macroprolactinemia
  15. Prevalence and re-evaluation of macroprolactinemia in hyperprolactinemic patients: a retrospective study in the Turkish population
  16. Defining dried blood spot diameter: implications for measurement and specimen rejection rates
  17. Screening primary aldosteronism by plasma aldosterone-to-angiotensin II ratio
  18. Assessment of serum free light chain measurements in a large Chinese chronic kidney disease cohort: a multicenter real-world study
  19. Beyond the Hydrashift assay: the utility of isoelectric focusing for therapeutic antibody and paraprotein detection
  20. Direct screening and quantification of monoclonal immunoglobulins in serum using MALDI-TOF mass spectrometry without antibody enrichment
  21. Effect of long-term frozen storage on stability of kappa free light chain index
  22. Impact of renal function impairment on kappa free light chain index
  23. Standardization challenges in antipsychotic drug monitoring: insights from a national survey in Chinese TDM practices
  24. Potential coeliac disease in children: a single-center experience
  25. Vitamin D metabolome in preterm infants: insights into postnatal metabolism
  26. Candidate Reference Measurement Procedures and Materials
  27. Development of commutable candidate certified reference materials from protein solutions: concept and application to human insulin
  28. Reference Values and Biological Variations
  29. Biological variation of serum cholinesterase activity in healthy subjects
  30. Hematology and Coagulation
  31. Diagnostic performance of morphological analysis and red blood cell parameter-based algorithms in the routine laboratory screening of heterozygous haemoglobinopathies
  32. Cancer Diagnostics
  33. Promising protein biomarkers for early gastric cancer: clinical performance of combined detection
  34. Infectious Diseases
  35. The accuracy of presepsin in diagnosing neonatal late-onset sepsis in critically ill neonates: a prospective study
  36. Corrigendum
  37. The Unholy Grail of cancer screening: or is it just about the Benjamins?
  38. Letters to the Editor
  39. Analytical validation of hemolysis detection on GEM Premier 7000
  40. Reconciling reference ranges and clinical decision limits: the case of thyroid stimulating hormone
  41. Contradictory definitions give rise to demands for a right to unambiguous definitions
  42. Biomarkers to measure the need and the effectiveness of therapeutic supplementation: a critical issue
https://doi.org/10.1515/cclm-2025-0203
Keywords for this article
monoclonal gammopathies; M-protein; MALDI-TOF mass spectrometry; screening; quantification

Articles in the same Issue

  1. Frontmatter
  2. Editorial
  3. Macroprolactinaemia – some progress but still an ongoing problem
  4. Review
  5. Understanding the circulating forms of cardiac troponin: insights for clinical practice
  6. Opinion Papers
  7. New insights in preanalytical quality
  8. IFCC recommendations for internal quality control practice: a missed opportunity
  9. Genetics and Molecular Diagnostics
  10. Evaluation of error detection and treatment recommendations in nucleic acid test reports using ChatGPT models
  11. General Clinical Chemistry and Laboratory Medicine
  12. Pre-analytical phase errors constitute the vast majority of errors in clinical laboratory testing
  13. Improving the efficiency of quality control in clinical laboratory with an integrated PBRTQC system based on patient risk
  14. IgA-type macroprolactin among 130 patients with macroprolactinemia
  15. Prevalence and re-evaluation of macroprolactinemia in hyperprolactinemic patients: a retrospective study in the Turkish population
  16. Defining dried blood spot diameter: implications for measurement and specimen rejection rates
  17. Screening primary aldosteronism by plasma aldosterone-to-angiotensin II ratio
  18. Assessment of serum free light chain measurements in a large Chinese chronic kidney disease cohort: a multicenter real-world study
  19. Beyond the Hydrashift assay: the utility of isoelectric focusing for therapeutic antibody and paraprotein detection
  20. Direct screening and quantification of monoclonal immunoglobulins in serum using MALDI-TOF mass spectrometry without antibody enrichment
  21. Effect of long-term frozen storage on stability of kappa free light chain index
  22. Impact of renal function impairment on kappa free light chain index
  23. Standardization challenges in antipsychotic drug monitoring: insights from a national survey in Chinese TDM practices
  24. Potential coeliac disease in children: a single-center experience
  25. Vitamin D metabolome in preterm infants: insights into postnatal metabolism
  26. Candidate Reference Measurement Procedures and Materials
  27. Development of commutable candidate certified reference materials from protein solutions: concept and application to human insulin
  28. Reference Values and Biological Variations
  29. Biological variation of serum cholinesterase activity in healthy subjects
  30. Hematology and Coagulation
  31. Diagnostic performance of morphological analysis and red blood cell parameter-based algorithms in the routine laboratory screening of heterozygous haemoglobinopathies
  32. Cancer Diagnostics
  33. Promising protein biomarkers for early gastric cancer: clinical performance of combined detection
  34. Infectious Diseases
  35. The accuracy of presepsin in diagnosing neonatal late-onset sepsis in critically ill neonates: a prospective study
  36. Corrigendum
  37. The Unholy Grail of cancer screening: or is it just about the Benjamins?
  38. Letters to the Editor
  39. Analytical validation of hemolysis detection on GEM Premier 7000
  40. Reconciling reference ranges and clinical decision limits: the case of thyroid stimulating hormone
  41. Contradictory definitions give rise to demands for a right to unambiguous definitions
  42. Biomarkers to measure the need and the effectiveness of therapeutic supplementation: a critical issue
Sign up now to receive a 20% welcome discount
Institutional Access
How does access work?
Have an idea on how to improve our website?
Please write us.
© 2025 De Gruyter Brill
Downloaded on 17.9.2025 from https://www.degruyterbrill.com/document/doi/10.1515/cclm-2025-0203/html
Scroll to top button