Journal Information
Journal ID (publisher-id): BM
Journal ID (nlm-ta): Biochem Med
Title: Biochemia Medica
Abbreviated Title: Biochem. Med.
ISSN (print): 1330-0962
ISSN (electronic): 1846-7482
Publisher: Croatian Society of Medical Biochemistry and Laboratory Medicine
Article Information
Copyright: 2015, Croatian Society of Medical Biochemistry
Date received: 04 January 2015
Date accepted: 28 August 2015
Publication date (electronic): 15 October 2015
Publication date (print): 15 October 2015
Volume: 25
Issue: 3
Pages: 430-438
Publisher ID: bm-25-430
DOI: 10.11613/BM.2015.044
A comparison between two different automated total 25-hydroxyvitamin D immunoassay methods using liquid chromatography-tandem mass spectrometry
Fatma Emel Kocak[1]
Bahadir Ozturk[2]
Ozben Ozden Isiklar[3]
Ozlem Genc[4]
Ali Unlu[2]
Irfan Altuntas[1]
[1] Dumlupinar University, Faculty of Medicine, Department of Medical Biochemistry, Kutahya, Turkey
[2] Selcuk University, Faculty of Medicine, Department of Medical Biochemistry, Konya, Turkey
[3] Dumlupinar University, Evliya Celebi Education and Research Hospital, Department of Medical Biochemistry, Kutahya, Turkey
[4] Dumlupinar University, Faculty of Medicine, Department of Medical Microbiology, Kutahya, Turkey
Author notes:
Corresponding author: dremelk@hotmail.com
Introduction
Total 25-hydroxyvitamin D [25(OH)D] is the most reliable indicator of vitamin D status. In this study, we compared two automated immunoassay methods, the Abbott Architect 25-OH Vitamin D assay and the Roche Cobas Vitamin D total assay, with the liquid chromatography-tandem mass spectrometry (LC-MS/MS).
Materials and methods
One hundred venous blood samples were randomly selected from routine vitamin D tests. Two of the serum aliquots were analyzed at the Abbott Architect i2000 and the Roche Cobas 6000’s module e601 in our laboratory within the same day. The other serum aliquots were analyzed at the LC-MS/MS in different laboratory. Passing-Bablok regression analysis and Bland-Altman plot were used to compare methods. Inter-rater agreement was analyzed using kappa (κ) analysis.
Results
The Roche assay showed acceptable agreement with the LC-MS/MS based on Passing-Bablok analysis (intercept: -5.23 nmol/L, 95% CI: -8.73 to 0.19; slope: 0.97, 95% CI: 0.77 to 1.15). The Abbott assay showed proportional (slope: 0.77, 95% CI: 0.67 to 0.85) and constant differences (intercept: 17.08 nmol/L; 95% CI: 12.98 to 21.39). A mean bias of 15.1% was observed for the Abbott and a mean bias of -14.1% was observed for the Roche based on the Bland-Altman plots. We found strong to nearly perfect agreement in vitamin D status between the immunoassays and LC-MS/MS. (κ: 0.83 for Abbott, κ: 0.93 for Roche) using kappa analysis.
Keywords: 25-Hydroxyvitamin D; chromatography; immunoassay; methods; tandem mass spectrometry
