Abstract
Objectives
A matrix assisted laser desorption ionization time of flight mass spectrometry (MALDI-TOF MS) method (Mass-Fix) as a replacement for gel-based immunofixation (IFE) has been recently described. To utilize Mass-Fix clinically, a validated automated method was required. Our aim was to automate the pre-analytical processing, improve positive specimen identification and ergonomics, reduce paper data storage and increase resource utilization without increasing turnaround time.
Methods
Serum samples were batched and loaded onto a liquid handler along with reagents and a barcoded sample plate. The pre-analytical steps included: (1) Plating immunopurification beads. (2) Adding 10 μl of serum. (3) Bead washing. (4) Eluting the immunoglobulins (Igs), and reducing to separate the heavy and light Ig chains. The resulting plate was transferred to a second low-volume liquid handler for MALDI plate spotting. MALDI-TOF mass spectra were collected. Integrated in-house developed software was utilized for sample tracking, driving data acquisition, data analysis, history tracking, and result reporting. A total of 1,029 residual serum samples were run using the automated system and results were compared to prior electrophoretic results.
Results
The automated Mass-Fix method was capable of meeting the validation requirements of concordance with IFE, limit of detection (LOD), sample stability and reproducibility with a low repeat rate. Automation and integrated software allowed a single user to process 320 samples in an 8 h shift. Software display facilitated identification of monoclonal proteins. Additionally, the process maintains positive specimen identification, reduces manual pipetting, allows for paper free tracking, and does not significantly impact turnaround time (TAT).
Conclusions
Mass-Fix is ready for implementation in a high-throughput clinical laboratory.
Research funding: None declared.
Author contributions: All authors have accepted responsibility for the entire content of this manuscript and approved its submission.
Competing interests: DLM and SD have intellectual property rights encompassing the Mass-Fix process which have been licensed to The Binding Site. All other authors state no conflict of interest.
Ethical approval: The local Institutional Review Board deemed the study exempt from review.
References
1. Litwin, CM, Anderson, SK, Philipps, G, Martins, TB, Jaskowski, TD, Hill, HR. Comparison of capillary zone and immunosubtraction with agarose gel and immunofixation electrophoresis for detecting and identifying monoclonal gammopathies. Am J Clin Pathol 1999;112:411–7. https://doi.org/10.1093/ajcp/112.3.411.Search in Google Scholar PubMed
2. Mills, JR, Murray, DL. Identification of friend or foe: the laboratory challenge of differentiating M-proteins from monoclonal antibody therapies. J Appl Lab Med 2017;1:421–31. https://doi.org/10.1373/jalm.2016.020784.Search in Google Scholar PubMed
3. Martinez-Lopez, J, Lahuerta, JJ, Pepin, F, Gonzalez, M, Barrio, S, Ayala, R, et al.. Prognostic value of deep sequencing method for minimal residual disease detection in multiple myeloma. Blood 2014;123:3073–9. https://doi.org/10.1182/blood-2014-01-550020.Search in Google Scholar PubMed PubMed Central
4. Barnidge, DR, Tschumper, RC, Theis, JD, Snyder, MR, Jelinek, DF, Katzmann, JA, et al.. Monitoring M-proteins in patients with multiple myeloma using heavy-chain variable region clonotypic peptides and LC-MS/MS. J Proteome Res 2014;13:1905–10. https://doi.org/10.1021/pr5000544.Search in Google Scholar PubMed
5. Bergen, HR3rd, Dasari, S, Dispenzieri, A, Mills, JR, Ramirez-Alvarado, M, Tschumper, RC, et al.. Clonotypic light chain peptides identified for monitoring minimal residual disease in multiple myeloma without bone marrow aspiration. Clin Chem 2016;62:243–51. https://doi.org/10.1373/clinchem.2015.242651.Search in Google Scholar PubMed PubMed Central
6. 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
7. Barnidge, DR, Dispenzieri, A, Merlini, G, Katzmann, JA, Murray, DL. Monitoring free light chains in serum using mass spectrometry. Clin Chem Lab Med 2016;54:1073–83. https://doi.org/10.1515/cclm-2015-0917.Search in Google Scholar PubMed
8. Barnidge, DR, Griffin, TJ, Murray, DL. Using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry to detect monoclonal immunoglobuli light chains in serum and urine. Rapid Commun Mass Sp 2015;29:1–4. https://doi.org/10.1002/rcm.7314.Search in Google Scholar PubMed
9. 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
10. Milani, P, Murray, DL, Barnidge, DR, Kohlhagen, MC, Mills, JR, Merlini, G, et al.. The utility of MASS-FIX to detect and monitor monoclonal proteins in the clinic. Am J Hematol 2017;92:772–9. https://doi.org/10.1002/ajh.24772.Search in Google Scholar PubMed
11. Kyle, RA, Therneau, TM, Rajkumar, SV, Larson, DR, Plevak, MF, Offord, JR, et al.. Prevalence of monoclonal gammopathy of undetermined significance. The New Engl J Med 2006;354:1362–9. https://doi.org/10.1056/nejmoa054494.Search in Google Scholar
12. Jacobs, JFM, Turner, KA, Graziani, MS, Frinack, JL, Ettore, MW, Tate, JR, et al.. An international multi-center serum protein electrophoresis accuracy and M-protein isotyping study. Part II: limit of detection and follow-up of patients with small M-proteins. Clin Chem Lab Med 2020;58:547–59. https://doi.org/10.1515/cclm-2019-1105.Search in Google Scholar PubMed
13. Turner, KA, Frinack, JL, Ettore, MW, Tate, JR, Graziani, MS, Jacobs, JFM, et al.. An international multi-center serum protein electrophoresis accuracy and M-protein isotyping study. Part I: factors impacting limit of quantitation of serum protein electrophoresis. Clin Chem Lab Med 2020;58:533–46. https://doi.org/10.1515/cclm-2019-1104.Search in Google Scholar PubMed
14. 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
15. Kumar, S, Murray, D, Dasari, S, Milani, P, Barnidge, D, Madden, B, et al.. Assay to rapidly screen for immunoglobulin light chain glycosylation: a potential path to earlier AL diagnosis for a subset of patients. Leukemia 2019;33:254–7. https://doi.org/10.1038/s41375-018-0194-x.Search in Google Scholar PubMed
16. Mills, JR, Barnidge, DR, Dispenzieri, A, Murray, DL. High sensitivity blood-based M-protein detection in sCR patients with multiple myeloma. Blood Cancer J 2017;7: e590. https://doi.org/10.1038/bcj.2017.75.Search in Google Scholar PubMed PubMed Central
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