Jump to ContentJump to Main Navigation
Show Summary Details
In This Section

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 / Lackner, Karl J. / Lippi, Giuseppe / Melichar, Bohuslav / Payne, Deborah A. / Schlattmann, Peter / Tate, Jillian R.

12 Issues per year


IMPACT FACTOR 2016: 3.432

CiteScore 2016: 2.21

SCImago Journal Rank (SJR) 2015: 0.873
Source Normalized Impact per Paper (SNIP) 2015: 0.982

Online
ISSN
1437-4331
See all formats and pricing
In This Section
Volume 45, Issue 3 (Mar 2007)

Issues

International Standard for serum vitamin B12 and serum folate: international collaborative study to evaluate a batch of lyophilised serum for B12 and folate content

Susan J. Thorpe
  • National Institute for Biological Standards and Control, Potters Bar, Hertfordshire, UK
/ Alan Heath
  • National Institute for Biological Standards and Control, Potters Bar, Hertfordshire, UK
/ Sheena Blackmore
  • UKNEQAS Scheme for Haematinics, Good Hope Hospital, Sutton Coldfield, UK
/ Anne Lee
  • UKNEQAS Scheme for Haematinics, Good Hope Hospital, Sutton Coldfield, UK
/ Malcolm Hamilton
  • UKNEQAS Scheme for Haematinics, Good Hope Hospital, Sutton Coldfield, UK
/ Sean O'Broin
  • St James's Hospital, Dublin, Ireland
/ Bryant C. Nelson
  • National Institute of Standards and Technology, Gaithersburg, MD, USA
/ Christine Pfeiffer
  • National Center for Environmental Health, Centers for Disease Control and Prevention, Atlanta, GA, USA

Abstract

Background: Vitamin B12 and folate measurements in serum show wide inter-methodology variability. This variability appears to be due in part to the lack of standardisation against internationally accepted reference materials. Pooled human serum, lyophilised in ampoules and designated 03/178, was therefore evaluated by 24 laboratories in seven countries for its suitability to serve as an International Standard (IS) for B12 and folate.

Methods: IS 03/178 was assayed using a range of commercial analysers, microbiological assays and, for folate, candidate reference methods based on liquid chromatography coupled to isotope-dilution tandem mass spectrometry (LC/MS/MS).

Results: Mean vitamin B12 and folate values for reconstituted 03/178 across all laboratories and methods were 480 pg/mL [coefficient of variation (CV) 12.8%] and 5.52 ng/mL (CV 17.1%), respectively. The total folate content of reconstituted 03/178, determined using LC/MS/MS, was 12.1 nmol/L (equivalent to 5.33 ng/mL), made up of 9.75 nmol/L 5-methyl tetrahydrofolic acid (5MeTHF; CV 5.5%), 1.59 nmol/L 5-formyl tetrahydrofolic acid (5FoTHF; CV 4.2%) and 0.74 nmol/L folic acid (FA; CV 31.6%). The inclusion of three serum samples in the study with different B12 and folate levels demonstrated a considerable reduction in inter-laboratory variability when the B12 and folate content of the samples was determined relative to the IS 03/178 rather than to the analyser calibration. IS 03/178 demonstrated satisfactory long-term stability in accelerated degradation studies.

Conclusions: Use of IS 03/178 to standardise serum B12 and folate assays reduced inter-laboratory variability. The World Health Organization (WHO) Expert Committee on Biological Standardisation established 03/178 as the first IS for serum vitamin B12 and serum folate, with assigned values of 480 pg/mL of vitamin B12 and 12.1 nmol/L folate when the lyophilised contents of the ampoule are reconstituted with 1 mL of water.

Clin Chem Lab Med 2007;45:380–6.

Keywords: folate; liquid chromatography coupled to isotope-dilution tandem mass spectrometry (LC/MS/MS); 5-methyl tetrahydrofolic acid (5MeTHF); reference; standardisation; vitamin B12

References

  • 1.

  • 2.

  • 3.

  • 4.

  • 5.

  • 6.

  • 7.

  • 8.

  • 9.

  • 10.

  • 11.

  • 12.

  • 13.

  • 14.

About the article

Corresponding author: Dr. S.J. Thorpe, Parenterals Section, Biotherapeutics Group, National Institute for Biological Standards and Control, Blanche Lane, South Mimms, Potters Bar, Hertfordshire EN6 3QG, UK Phone: +44-1707-641251, Fax: +44-1707-641053,


Received: October 23, 2006

Accepted: December 20, 2006

Published in Print: 2007-03-01



Citation Information: Clinical Chemical Laboratory Medicine, ISSN (Online) 1437-4331, ISSN (Print) 1434-6621, DOI: https://doi.org/10.1515/CCLM.2007.072. Export Citation

Citing Articles

Here you can find all Crossref-listed publications in which this article is cited. If you would like to receive automatic email messages as soon as this article is cited in other publications, simply activate the “Citation Alert” on the top of this page.

[1]
Vinod Devalia, Malcolm S. Hamilton, and Anne M. Molloy
British Journal of Haematology, 2014, Volume 166, Number 4, Page 496
[2]
M.L. Samaniego-Vaesken, E. Alonso-Aperte, and G. Varela-Moreiras
Food Chemistry, 2014
[5]
Emmanuel Minet, Graham Errington, Gerhard Scherer, Kirk Newland, Mehran Sharifi, Brian Bailey, Mike McEwan, and Francis Cheung
BMC Research Notes, 2011, Volume 4, Number 1, Page 391
[6]
Sheena Blackmore, Malcolm Hamilton, Anne Lee, Mark Worwood, Matthew Brierley, Alan Heath, and Susan J. Thorpe
Clinical Chemistry and Laboratory Medicine, 2008, Volume 46, Number 10
[7]
Leslie JC Bluck
Current Opinion in Clinical Nutrition and Metabolic Care, 2009, Volume 12, Number 5, Page 495
[8]
Vu Thi Thu Hien, Nguyen Thi Lam, Nguyen Cong Khan, Nguyen Tri Dung, C Murray Skeaff, Bernard J Venn, Trevor Walmsley, Peter M George, Judy McLean, Matthew R Brown, and Timothy J Green
Public Health Nutrition, 2009, Volume 12, Number 07, Page 941
[9]
S. M. LEWIS
International Journal of Laboratory Hematology, 2009, Volume 31, Number 3, Page 253
[10]
Simon Wheeler
Proceedings of the Nutrition Society, 2008, Volume 67, Number 04, Page 437

Comments (0)

Please log in or register to comment.
Log in