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


     

Clinical Chemistry 55: 513-518, 2009. First published January 23, 2009; 10.1373/clinchem.2008.117002
This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow All Versions of this Article:
clinchem.2008.117002v1
55/3/513    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 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 Roche, D.
Right arrow Articles by Beaune, P.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Roche, D.
Right arrow Articles by Beaune, P.
(Clinical Chemistry. 2009;55:513-518.)
© 2009 American Association for Clinical Chemistry, Inc.

Automation and Analytical Techniques

Automated Determination of Serum {alpha}1-Antitrypsin by Antitryptic Activity Measurement

Denis Roche1,a, Alexandra Mesner1, Malik Al Nakib1, Frederic Leonard1 and Philippe Beaune1

1 AP-HP, Hôpital Européen Georges Pompidou, Service de Biochimie, 75015 Paris, France

aAddress correspondence to the author at: APHP, Hôpital Européen Georges Pompidou, 20-40 rue Leblanc, Paris Cedex 15, F 75908, France. Fax 331-156093393; e-mail denis.roche{at}egp.aphp.fr.

Background: {alpha}1-Antitrypsin (A1AT) deficiency is currently detectable by protein immunoassay, phenotyping, and genotyping of the S and Z mutations, but no fully automated method for standard biochemical analyzers is yet available. Here, we present a method that measures the antitryptic activity in serum. This method is rapid, automated, and allows the easy evaluation of a large cohort of patients.

Methods: Our automated assay involves determining serum antitryptic capacity on the Olympus AU 400 autoanalyzer by using trypsin and succinylated gelatin as substrate in the presence of trinitrobenzene sulfonic acid. The results are expressed as a percentage of inhibition of the reaction of trypsin with succinylated gelatin. After we performed analytical validation studies and reference-interval determination based on serum samples from 120 healthy persons, we tested the assay on deidentified samples from 120 patients with various pathologies (primarily pulmonary) of unexplained origin and normal A1AT concentrations and phenotypes.

Results: The analysis rate was up to 120 samples per hour. Intraassay CVs ranged from 3.1%–16.2%, and interassay CV was 7.5%. The reference population showed mean (SD) 58.4 (6.7)% inhibition. The detection limit was 9.5% inhibition. The 120 studied patients displayed significantly lower mean activity than 120 healthy individuals (P < 0.0001).

Conclusion: This assay is stable, reliable, and easily automated by use of open-system analyzers, allowing for the rapid evaluation of patients. After further validation on a larger randomized cohort, this new approach should function as a useful method to explore A1AT deficiency, especially in large-scale studies.






HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Copyright © 2009 by the American Association for Clinical Chemistry.