Influence of Vitamin D Binding Protein on Accuracy of 25-Hydroxyvitamin D Measurement Using the ADVIA Centaur Vitamin D Total Assay

• Published in: International Journal of Endocrinology Vol. 2014; no. 2014; pp. 536 - 547-158
• Main Authors: Shalhoub, Victoria, Spears, Ryan, Wilson, Kimberly, Freeman, James, Sibley, Paul
• Format: Journal Article
• Language: English
• Published: Cairo, Egypt Hindawi Limiteds 01-01-2014; Hindawi Publishing Corporation; John Wiley & Sons, Inc; Hindawi Limited
• Subjects: Alfacalcidol; Analysis; Antibodies; Automation; Bias; Binding proteins; Binding sites; Calcifediol; Chemical properties; Chromatography; Endocrinology; Genetic aspects; Immunoassay; Laboratories; Liquid chromatography; Mass spectrometry; Measurement; Metabolites; Methods; Physiological aspects; Proteins; Scientific imaging; Standardization; Vitamin D; Womens health; United States; United States > US
• ISSN: 1687-8337; 1687-8345
• DOI: 10.1155/2014/691679

Vitamin D status in different populations relies on accurate measurement of total serum 25-hydroxyvitamin D [25(OH)D] concentrations [i.e., 25(OH)D3 and 25(OH)D2]. This study evaluated agreement between the ADVIA Centaur Vitamin D Total assay for 25(OH)D testing (traceable to the NIST-Ghent reference method procedure) and a liquid chromatography tandem mass spectrometry (LC-MS/MS) method for various populations with different levels of vitamin D binding protein (DBP). Total serum 25(OH)D concentrations were measured for 36 pregnant women, 40 hemodialysis patients, and 30 samples (DBP-spiked or not) from healthy subjects. ELISA measured DBP levels. The mean serum DBP concentrations were higher for pregnancy (415 μg/mL) and lower for hemodialysis subjects (198 μg/mL) than for healthy subjects and were highest for spiked serum (545 μg/mL). The average bias between the ADVIA Centaur assay and the LC-MS/MS method was −1.4% (healthy), −6.1% (pregnancy), and 4.4% (hemodialysis). The slightly greater bias for samples from some pregnancy and hemodialysis subjects with serum DBP levels outside of the normal healthy range fell within a clinically acceptable range—reflected by analysis of their low-range (≤136 μg/mL), medium-range (137–559 μg/mL), and high-range (≥560 μg/mL) DBP groups. Thus, the ADVIA Centaur Vitamin D Total assay demonstrates acceptable performance compared with an LC-MS/MS method for populations containing different amounts of DBP.