Clinical Chemistry
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

Clinical Chemistry 54: 1349-1355, 2008. First published June 6, 2008; 10.1373/clinchem.2007.100081
This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow All Versions of this Article:
clinchem.2007.100081v1
54/8/1349    most recent
Right arrow Alert me when this article is cited
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 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 Google Scholar
Google Scholar
Right arrow Articles by Cattozzo, G.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Cattozzo, G.
Related Collections
Right arrow General Clinical Chemistry
(Clinical Chemistry. 2008;54:1349-1355.)
© 2008 American Association for Clinical Chemistry, Inc.

General Clinical Chemistry

Commutable Calibrator with Value Assigned by the IFCC Reference Procedure to Harmonize Serum Lactate Dehydrogenase Activity Results Measured by 2 Different Methods

Giampaolo Cattozzo1,a, Elena Guerra2, Ferruccio Ceriotti2, Carlo Franzini3 on behalf of the Enzyme Working Group of the Italian Society of Clinical Biochemistry and Clinical Molecular Biology (SIBioC)

1 A. O. Ospedale di Circolo e Fondazione Macchi, Varese, Italy; 2 Diagnostica e Ricerca S. Raffaele SpA, IRCCS S. Raffaele, Milano, Italy; 3 Università di Milano, Milano, Italy.

aAddress correspondence to this author at: Laboratorio di Analisi Ospedale F. Del Ponte, A. O. Ospedale di Circolo e Fondazione Macchi, Via F. Del Ponte n. 19, 21100 Varese, Italy. Fax +390332299408; e-mail giampaolo.cattozzo{at}gmail.com.

Background: The availability of commutable calibrator materials may ease considerably the task of harmonizing assay results and ensuring their traceability to reference procedures. We sought to verify the commutability of potential calibrator materials and evaluate their effectiveness in harmonizing LDH results by 2 measurement methods.

Methods: We measured LDH in 109 serum samples and 31 materials, including frozen serum pools (with either normal or abnormal isoenzyme patterns), commercial stabilized materials, and the ERM-AD453/IFCC reference material. We assayed LDH activity with the IFCC reference procedure and with 2 commercial methods, 1 using the lactate-to-pyruvate (LP) reaction, and the other the pyruvate-to-lactate (PL) reaction. We selected a commutable material, with LDH value assigned by the reference procedure, as a calibrator for recalculating the results for patient sera by both LP and PL, thereby making them traceable to the IFCC reference procedure.

Results: Original values for patient sera (n = 109) by the 2 commercial methods showed a mean (SD) PL/LP ratio of 1.97 (0.03); this ratio changed to 1.06 (0.02) after recalculation of results. Linear regression of PL vs LP recalibrated values gave y = 1.108x – 9.7. At the clinically important concentration of 250 U/L (upper reference limit), the systematic difference between methods was 6.8%, which met our proposed quality specifications for inaccuracy and total error.

Conclusions: By properly selecting the calibrator, the results of serum LDH measurement by 2 different methods may be harmonized and made traceable to the selected highest (reference) metrological level.






HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Copyright © 2008 by the American Association for Clinical Chemistry.