HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) Supplement All Versions of this Article: clinchem.2007.100412v1 54/9/1443    most recent Submit an electronic Letter to the Editor about this paper Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in ISI Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Google Scholar Articles by Fuchs, S. A. Articles by de Koning, T. J. PubMed PubMed Citation Articles by Fuchs, S. A. Articles by de Koning, T. J.

Two Mass-Spectrometric Techniques for Quantifying Serine Enantiomers and Glycine in Cerebrospinal Fluid: Potential Confounders and Age-Dependent Ranges

¹ Department of Metabolic and Endocrine Diseases and Department of Biomedical Genetics, University Medical Center Utrecht, Utrecht, The Netherlands; ² Department of Metabolic Diseases, University Medical Center Utrecht, Utrecht, The Netherlands.

^aAddress correspondence to this author at: Department of Metabolic and Endocrine Diseases, University Medical Center Utrecht, Postbox 85090, 3508 AB Utrecht, The Netherlands. Fax +31887555350; e-mail S.Fuchs{at}umcutrecht.nl.

Background: The recent discovery and specific functions of D-amino acids in humans are bound to lead to the revelation of D-amino acid abnormalities in human disorders. Therefore, high-throughput analysis techniques are warranted to determine D-amino acids in biological fluids in a routine laboratory setting.

Methods: We developed 2 chromatographic techniques, a nonchiral derivatization with chiral (chirasil-L-val column) separation in a GC-MS system and a chiral derivatization with Marfey’s reagent and LC- MS analysis. We validated the techniques for D-serine, L-serine, and glycine determination in cerebrospinal fluid (CSF), evaluated several confounders, and determined age-dependent human concentration ranges.

Results: Quantification limits for D-serine, L-serine, and glycine in cerebrospinal fluid were 0.14, 0.44, and 0.14 µmol/L, respectively, for GC-MS and 0.20, 0.41, and 0.14 µmol/L for LC-MS. Within-run imprecision was <3% for both methods, and between-run imprecision was <13%. Comparison of both techniques with Deming regression yielded coefficients of 0.90 (D-serine), 0.92 (L-serine), and 0.96 (glycine). Sample collection, handling, and transport is uncomplicated—there is no rostrocaudal CSF gradient, no effect of storage at 4 °C for 1 week before storage at –80 °C, and no effect of up to 3 freeze/thaw cycles. Conversely, contamination with erythrocytes increased D-serine, L-serine, and glycine concentrations. CSF concentrations for 145 apparently healthy controls demonstrated markedly and specifically increased (5 to 9 times) D-serine concentrations during early central nervous system development.

Conclusions: These 2 clinically applicable analysis techniques will help to unravel pathophysiologic, diagnostic, and therapeutic issues for disorders associated with central nervous system abnormalities, NMDA-receptor dysfunction, and other pathology associated with D-amino acids.