Comparison of four different immunoassays and a rapid isotope-dilution liquid chromatography-tandem mass spectrometry assay for serum folate

Lizi Jin; Youli Lu; Xilian Yi; Meiwei Zhang; Jiangtao Zhang; Weiyan Zhou; Jie Zeng; Tianjiao Zhang; Chuanbao Zhang

doi:10.1515/cclm-2021-1283

Article

Comparison of four different immunoassays and a rapid isotope-dilution liquid chromatography-tandem mass spectrometry assay for serum folate

Lizi Jin , Youli Lu , Xilian Yi , Meiwei Zhang , Jiangtao Zhang , Weiyan Zhou , Jie Zeng , Tianjiao Zhang and Chuanbao Zhang

Published/Copyright: June 9, 2022

Published by

Become an author with De Gruyter Brill

Submit Manuscript Author Information

From the journal Clinical Chemistry and Laboratory Medicine (CCLM) Volume 60 Issue 9

Abstract

Objectives

Accurate measurement of serum folate is essential for the diagnosis and management of various disorders. This study aims to investigate the between-method differences of four immunoassays and a rapid isotope-dilution liquid chromatography-tandem mass spectrometry (ID-LC-MS/MS) method.

Methods

Roche Cobas (USA), Abbott Alinity i2000 (USA), Beckman Coulter Access (USA), Mindray CL-6000i (China), and the ID-LC-MS/MS method were compared using 46 human serum samples. The results were analysed by Passing–Bablok regressions and Bland–Altman plots. A bias of 13.31% based on biological variation was used as the bias criterion.

Results

All the within-run and total coefficients of variation (CVs) met the specification. The folate concentrations determined by all the assays were significantly different (p=0.0028). All assays had correlation coefficients over 0.97 with each other. The 95% confidence intervals (CIs) for the slope seldom contained 1 and few 95% CIs for the intercept contained 0 in the regression equations. Compared to ID-LC-MS/MS, the biases of all assays ranged from −20.91 to 13.56 nmol/L, and the mean relative biases ranged from −9.85 to 40.33%. The predicted mean relative biases at the medical decision levels rarely met the criterion.

Conclusions

Assays for serum folate had good correlations with each other but lacked good agreement. The accuracy and consistency of assays for serum folate should be measured and assessed routinely. Standardization work to improve the accuracy of serum folate assays, such as the extension of traceability to reference methods or materials, calibration standardization efforts, and assay-adjusted cut-offs should be promoted.

Keywords: immunoassays; isotope-dilution liquid chromatography-tandem mass spectrometry (ID-LC-MS/MS); method comparison; serum folate

Corresponding authors: Tianjiao Zhang, MD and Chuanbao Zhang, MD, National Center for Clinical Laboratories, Institute of Geriatric Medicine, Chinese Academy of Medical Sciences, Beijing Hospital/National Center of Gerontology, Beijing, P.R. China; Chinese Academy of Medical Sciences and Peking Union Medical College, No. 1 Dahua Road, Dongcheng District 100730, Beijing, P.R. China, Phone: +86 010-58115059, Fax: +86 010-65132968, E-mail: tjzhang@nccl.org.cn (T. Zhang), cbzhang@nccl.org.cn (C. Zhang)

Lizi Jin, Youli Lu, Xilian Yi and Meiwei Zhang contributed equally to this work.

Funding source: The National Key Research and Development Program of China

Award Identifier / Grant number: 2018YFC1002204

Acknowledgments

We are grateful for the kind help and technique guidance of engineers from Abbott, Roche, Beckman, and Mindray.

Research funding: The National Key Research and Development Program of China (2018YFC1002204).
Author contributions: All authors have accepted responsibility for the entire content of this manuscript and approved its submission.
Competing interests: Authors state no conflict of interest.
Informed consent: This study was approved for the exemption from informed consent.
Ethical approval: The study was approved by the Ethics Committee of Beijing Hospital and the Ethics Committee of Nanjing Maternal and Child Health Hospital.

References

1. Nazki, FH, Sameer, AS, Ganaie, BA. Folate: metabolism, genes, polymorphisms and the associated diseases. Gene 2014;533:11–20. https://doi.org/10.1016/j.gene.2013.09.063.Search in Google Scholar

2. Shulpekova, Y, Nechaev, V, Kardasheva, S, Sedova, A, Kurbatova, A, Bueverova, E, et al.. The concept of folic acid in health and disease. Molecules 2021;26:3731. https://doi.org/10.3390/molecules26123731.Search in Google Scholar

3. Pope, S, Artuch, R, Heales, S, Rahman, S. Cerebral folate deficiency: analytical tests and differential diagnosis. J Inherit Metab Dis 2019;42:655–72. https://doi.org/10.1002/jimd.12092.Search in Google Scholar

4. MRC Vitamin Study Research Group. Prevention of neural tube defects: results of the medical research council vitamin study. Lancet 1991;338:131–7.10.1016/0140-6736(91)90133-ASearch in Google Scholar

5. Fofou-Caillierez, MB, Guéant-Rodriguez, RM, Alberto, JM, Chéry, C, Josse, T, Gérard, P, et al.. Vitamin B-12 and liver activity and expression of methionine synthase are decreased in fetuses with neural tube defects. Am J Clin Nutr 2019;109:674–83. https://doi.org/10.1093/ajcn/nqy340.Search in Google Scholar PubMed

6. Watkins, D, Rosenblatt, DS. Immunodeficiency and inborn disorders of vitamin B12 and folate metabolism. Curr Opin Clin Nutr Metab Care 2020;23:241–6. https://doi.org/10.1097/mco.0000000000000668.Search in Google Scholar

7. Socha, DS, DeSouza, SI, Flagg, A, Sekeres, M, Rogers, HJ. Severe megaloblastic anemia: vitamin deficiency and other causes. Cleve Clin J Med 2020;87:153–64. https://doi.org/10.3949/ccjm.87a.19072.Search in Google Scholar PubMed

8. Sobczyńska-Malefora, A, Harrington, DJ. Laboratory assessment of folate (vitamin B9) status. J Clin Pathol 2018;71:949–56. https://doi.org/10.1136/jclinpath-2018-205048.Search in Google Scholar PubMed

9. Gunter, EW, Bowman, BA, Caudill, SP, Twite, DB, Adams, MJ, Sampson, EJ. Results of an international round robin for serum and whole-blood folate. Clin Chem 1996;42:1689–94. https://doi.org/10.1093/clinchem/42.10.1689.Search in Google Scholar

10. Wilson, DH, Williams, G, Herrmann, R, Wiesner, D, Brookhart, P. Issues in immunoassay standardization: the ARCHITECT folate model for intermethod harmonization. Clin Chem 2005;51:684–7. https://doi.org/10.1373/clinchem.2004.042358.Search in Google Scholar PubMed

11. Blackmore, S, Pfeiffer, CM, Lee, A, Fazili, Z, Hamilton, MS. Isotope dilution-LC-MS/MS reference method assessment of serum folate assay accuracy and proficiency testing consensus mean. Clin Chem 2011;57:986–94. https://doi.org/10.1373/clinchem.2010.160135.Search in Google Scholar PubMed

12. Verstraete, J, Kiekens, F, Strobbe, S, De Steur, H, Gellynck, X, Van Der Straeten, D, et al.. Clinical determination of folates: recent analytical strategies and challenges. Anal Bioanal Chem 2019;411:4383–99. https://doi.org/10.1007/s00216-019-01574-y.Search in Google Scholar PubMed

13. Braga, F, Frusciante, E, Ferraro, S, Panteghini, M. Trueness evaluation and verification of inter-assay agreement of serum folate measuring systems. Clin Chem Lab Med 2020;58:1697–705. https://doi.org/10.1515/cclm-2019-0928.Search in Google Scholar PubMed

14. Lacher, DA, Hughes, JP, Carroll, MD. Biological variation of laboratory analytes based on the 1999–2002 National health and nutrition examination survey. Natl Health Stat Report 2010;21:1–7.Search in Google Scholar

15. Owen, WE, Roberts, WL. Comparison of five automated serum and whole blood folate assays. Am J Clin Pathol 2003;120:121–6. https://doi.org/10.1309/l2u6hh5kayg48l40.Search in Google Scholar

16. Nelson, BC, Satterfield, MB, Sniegoski, LT, Welch, MJ. Simultaneous quantification of homocysteine and folate in human serum or plasma using liquid chromatography/tandem mass spectrometry. Anal Chem 2005;77:3586–93. https://doi.org/10.1021/ac050235z.Search in Google Scholar PubMed

17. EP09-A3, CLSI. Measurement procedure comparison and bias estimation using patient samples; approved guideline, 3rd ed. Wayne: Clinical and Laboratory Standards Institute; 2013.Search in Google Scholar

Supplementary Material

The online version of this article offers supplementary material (https://doi.org/10.1515/cclm-2021-1283).

Received: 2021-12-09

Accepted: 2022-06-01

Published Online: 2022-06-09

Published in Print: 2022-08-26

You are currently not able to access this content.

Articles in the same Issue

https://doi.org/10.1515/cclm-2021-1283

Keywords for this article

immunoassays; isotope-dilution liquid chromatography-tandem mass spectrometry (ID-LC-MS/MS); method comparison; serum folate