Determination of human reference values for serum total 1,25-dihydroxyvitamin D using an extensively validated 2D ID-UPLC-MS/MS method.

Autor: Dirks NF; Department of Clinical Chemistry, Endocrine Laboratory, VU University Medical Center, Amsterdam, The Netherlands., Martens F; Department of Clinical Chemistry, Endocrine Laboratory, VU University Medical Center, Amsterdam, The Netherlands., Vanderschueren D; Department of Clinical and Experimental Medicine KU Leuven, Laboratory of Clinical and Experimental Endocrinology, Leuven, Belgium; Clinical Department of Laboratory Medicine, University Hospitals Leuven, Leuven, Belgium., Billen J; Department of Clinical and Experimental Medicine KU Leuven, Laboratory of Clinical and Experimental Endocrinology, Leuven, Belgium; Clinical Department of Laboratory Medicine, University Hospitals Leuven, Leuven, Belgium., Pauwels S; Clinical Department of Laboratory Medicine, University Hospitals Leuven, Leuven, Belgium; Department of Cardiovascular Sciences, KU Leuven, Leuven, Belgium., Ackermans MT; Department of Clinical Chemistry, Laboratory of Endocrinology, Academic Medical Center, Amsterdam, The Netherlands., Endert E; Department of Clinical Chemistry, Laboratory of Endocrinology, Academic Medical Center, Amsterdam, The Netherlands., Heijer MD; Department of Internal Medicine, Endocrinology, VU University Medical Center, Amsterdam, The Netherlands., Blankenstein MA; Department of Clinical Chemistry, Endocrine Laboratory, VU University Medical Center, Amsterdam, The Netherlands., Heijboer AC; Department of Clinical Chemistry, Endocrine Laboratory, VU University Medical Center, Amsterdam, The Netherlands. Electronic address: a.heijboer@vumc.nl.
Jazyk: angličtina
Zdroj: The Journal of steroid biochemistry and molecular biology [J Steroid Biochem Mol Biol] 2016 Nov; Vol. 164, pp. 127-133. Date of Electronic Publication: 2015 Dec 10.
DOI: 10.1016/j.jsbmb.2015.12.003
Abstrakt: Background: To assess a patient's vitamin D status the precursor metabolite 25-hydroxyvitamin D can be determined. However, measurement of 1,25-dihydroxyvitamin D is required when disorders of 1a-hydroxylation, extrarenal 1a-hydroxylation, or vitamin D receptor defects are suspected.
Methods: The aim of this study was to determine reference values for 1,25-dihydroxyvitamin D 3 and D 2 using a 2D ID-UPLC-MS/MS method.
Results: The LC-MS/MS method, able to measure picomolar concentrations of both 1,25-dihydroxyvitamin D 3 and D 2 in human serum, was extensively validated. Intra-assay variations were <5% and 8.5% and <7.5% and 11%, for 1,25-dihydroxyvitamin D 3 and D 2 , respectively, over the whole dynamic range (3.1-376 and 3.1-652pmol/L). Limit of quantitation was 3.4pmol/L for both compounds. Our method correlated well with a published LC-MS/MS method (r=0.87) and with the average 1,25-dihydroxyvitamin D 3 results of the vitamin D External Quality Assessment Scheme (DEQAS) determined with LC-MS/MS (r=0.93). Reference ranges, determined in 96 plasma samples of healthy volunteers were 59-159pmol/L and <17pmol/L for respectively 1,25-dihydroxyvitamin D 3 and D 2 . The female part of the reference group showed a statistically significant decrease of 1,25-dihydroxyvitamin D 3 concentrations with age. The presence of significantly higher average 1,25-dihydroxyvitamin D 3 levels in premenopausal women taking oral contraceptive pills compared to postmenopausal women suggests that this effect is estrogen-related, as estrogens lead to a higher vitamin D binding protein.
Conclusions: The major finding of the present study is a reference interval of 59-159pmol/L for 1,25-dihydroxyvitamin D 3 determined with a highly sensitive and precise LC-MS/MS method.
(Copyright © 2015 Elsevier Ltd. All rights reserved.)
Databáze: MEDLINE
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