Evaluation of two automated immunoassays for 25-OH vitamin D: Comparison against LC–MS/MS

Performance evaluation of four 25-hydroxyvitamin D assays to measure 25-hydroxyvitamin D2

“…Although indirect, these assumptions support reports that 25(OH)D 3 supplementation is at least 30-50% more effective than 25(OH)D 2 in maintaining total serum 25(OH)D concentrations [8,10,[20][21][22][23][24][25][26]48,49]. Variability for automated and other methods in the measurement of 25(OH)D has been attributed to a variety of sources including differential recognition of 25(OH)D 3 and 25(OH)D 2 by the capture antibody [29][30][31][32], and 25(OH)D is a difficult analyte to measure due to its hydrophobic properties and tight binding to an abundance of serum binding proteins. Additionally, due to its lower affinity for binding proteins, 25(OH)D 2 in serum may be preferentially released and more subjects' diets would have changed such that serum 25(OH)D 2 and total serum 25(OH)D concentrations would rise as quickly as they did within the first few weeks concomitant with a decline in 25(OH)D 3 serum concentrations.…”

“…In the past, variability was reported in the ability of automated immunoassays to accurately measure serum 25(OH)D 2 concentrations [29][30][31][32]. The affinity for 25(OH)D 2 and other vitamin D metabolites was found to differ between assays, which-depending on the assay-reportedly overestimated [29,30,32], or underestimated 25(OH)D 2 concentrations [29,30,32,33].…”

Performance characteristics of six automated 25-hydroxyvitamin D assays: Mind your 3s and 2s

“…A deficiency cutoff of ≤ 20 ng/mL was used to assess qualitative agreement between immunoassay and LC-MS/MS (10) ( Our evaluation of accuracy verified the lack of harmonization and standardization among assays, which has been discussed frequently in the academic and clinical communities (12)(13)(14)(15)(16).…”

“…ACCEPTED MANUSCRIPT 16 The DiaSorin Liaison immunoassay was one of the first automated 25(OH)D assays on the market and therefore has the most comparative data available in the literature. (16,20).…”

Russian Association of Endocrinologists recommendations for diagnosis, treatment and prevention of vitamin D deficiency in adults

“…В DEQAS значения, полученные конкретны-ми лабораториями для рассылаемых ежеквартально образцов сыворотки, сравниваются как со средними значениями для конкретного метода определения витамина D (MM = Method Mean), средними значе-ниями всех методов, используемых лабораториями, участвующими в программе DEQAS (ALTM = AllLaboratory Trimmed Mean), а также универсальным стандартом (NIST = National Institute of Standards and Technology). Программа присуждает сертифи-кат качества, если целевая производительность ла-боратории соответствовала нахождению 80% всех результатов в диапазоне ± 30% от ALTM, что в 2013 г. было достигнуто только 59% лабораторий [79,80]. Таким образом, одним из путей может быть полу-чение статистического фактора коррекции между методами [81].…”