Clinical Chemistry Link to Randox Laboratories Web Site
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

Clinical Chemistry 53: 1448-1454, 2007. First published June 7, 2007; 10.1373/clinchem.2007.088682
This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow All Versions of this Article:
clinchem.2007.088682v1
53/8/1448    most recent
Right arrow Submit an electronic Letter to
the Editor about this paper
Right arrow Alert me when this article is cited
Right arrow Alert me when eLetters are posted
Right arrow Alert me if a correction is posted
Right arrow Citation Map
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in ISI Web of Science
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via ISI Web of Science (1)
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Daniel, Y. A.
Right arrow Articles by Dalton, R. N.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Daniel, Y. A.
Right arrow Articles by Dalton, R. N.
Related Collections
Right arrow Hematology
(Clinical Chemistry. 2007;53:1448-1454.)
© 2007 American Association for Clinical Chemistry, Inc.

Hematology

Quantification of Hemoglobin A2 by Tandem Mass Spectrometry

Yvonne A. Daniel1, Charles Turner2, Roberta M. Haynes1, Beverley J. Hunt1 and R. Neil Dalton3,a

1 Blood Sciences Delivery Unit, St. Thomas’ Hospital, Guy’s and St. Thomas’ NHS Foundation Trust, London, United Kingdom.
2 WellChild Laboratory, Evelina Children’s Hospital, Guy’s and St. Thomas’ NHS Foundation Trust, London, United Kingdom.
3 WellChild Laboratory, King’s College London, Evelina Children’s Hospital, London, United Kingdom.

aAddress correspondence to this author at: WellChild Laboratory, Arctic (1st Floor), Evelina Children’s Hospital, St. Thomas’ Hospital, London SE1 7EH, United Kingdom. Fax 44-207-188-4702; e-mail neil.dalton{at}kcl.ac.uk.

Background: Peptide-based analysis of whole blood using electrospray tandem mass spectrometry (MSMS) in multiple reaction monitoring (MRM) mode enables rapid detection and sequence confirmation of clinically significant hemoglobin (Hb) variants. We applied a similar, quantitative approach to the measurement of {delta}:β-globin peptide ratios as potential surrogate markers of HbA2, a biomarker used in population screening for β-thalassemia trait.

Methods: We studied 163 blood samples with normal HbA2 (%), 105 with increased HbA2, 43 with {delta}-chain variants, and 8 with Hb Lepore. All were tested by HPLC. The samples were also incubated with trypsin for 30 min at 37 °C for MSMS with flow injection analysis. MRMs for the {delta}- (T2, T3, and T14) and β- (T2, T3, and T13) globin tryptic peptides were acquired for 1 min, and {delta}:β peptide ratios were calculated. We used HPLC and MSMS to analyze 26 paired whole blood and dried blood spot samples after storage for 1, 8, and 29 days.

Results: Within- and between-assay imprecision values (CVs) were <6.1% and <8.4%, respectively, for the {delta}:β peptide ratios. Digests were stable at 10 °C for 6 days. Significant correlations (P <0.0001) between MSMS {delta}:β-globin peptide ratios and HPLC HbA2 allowed differentiation between increased HbA2 concentrations and concentrations within the reference interval and identification of Hb Lepore. This differentiation was repeatable by MSMS, but not by HPLC, after blood spot samples had been stored for 1 month.

Conclusion: This study validates the quantitative {delta}:β-globin peptide ratio as a surrogate marker of HbA2 and demonstrates the potential of rapid peptide-based MSMS for multiplexed, high-throughput protein biomarker characterization and quantification.




The following articles in journals at HighWire Press have cited this article:


Home page
 Clin. Chem.Home page
S. O. Brennan
Fifty-Eight Years of Hemoglobin Analysis
Clin. Chem., January 1, 2008; 54(1): 8 - 10.
[Full Text] [PDF]


HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Copyright © 2007 by the American Association for Clinical Chemistry.