Comparison of two different methods for routine 25(OH)D measurement in paediatric serum samples
Abstract
Over the last decade interest in automated assays for 25-hydroxy-vitamin D measurement have greatly increased. The presence of different metabolites of vitamin D in the blood influences measurement of its concentration. In paediatric subjects the basic interference is due to the presence of 3-epi-25(OH)D2/D3, which despite their biological inactivity, influences the total concentration of 25(OH)D.
Aim: We assessed the analytical performance and usefulness of two different assays for measurement of total 25(OH)D in children.
Materials and Methods: The study was performed in blood samples taken from 100 school-children aged 9–11 years. In all serum samples 25(OH)D total concentration was measured with the use of chemilumi-nescent assay, which is known to show no cross-reactivity with 3-epi-25(OH)D, and with the use of a newly developed enzyme-immunosorbent method.
Results: The mean 25(OH)D concentration in children measured with enzyme-immunosorbent assay (EIA) was significantly higher, at 28.06 ng/mL, than with the chemiluminescent assay (CLIA), at 21.13 ng/mL; < 0.0001. In children with optimal weight the average 25(OH)D was 32.93 ng/ml (EIA) and 21.5 ng/mL (CLIA) (p < 0.0001), respectively, whereas in a subgroup with overweight/obesity the mean concentra-tion of 25(OH)D was similar, at 23.2 ng/ml (EIA) and 20.76 ng/ml (CLIA) (p = 0.15). The nonparametric Spearman’s rank correlation of two methods equalled 0.47; 95%CI (0.11 to 0.60) with a significance level p < 0.0001. The calculated concordance correlation coefficient between two methods in the whole group was 0.26; 95%CI (0.17 to 0.35). In a subgroup of children with optimal body mass (N = 50) the concor-dance correlation coefficient was 0.18; 95%CI (0.06 to 0.29), whereas in children with overweight/obesity (N = 50) it was 0.44; 95%CI (0.29 to 057). Mean bias for the enzyme-immunosorbent method equalled 18.7%; +/- 1.96 SD (101.3% to -64%).
Conclusions: With reference to 25(OH)D measurement in children, Spearman’s correlation coefficient indicated “moderate correlation” between the two compared methods, whereas the strength of agree-ment (concordance) between both methods was characterised as “poor”. The proper selection of assay for accurate assessment of vitamin D status in paediatric samples is necessary to avoid misdiagnosis.
Keywords: Vitamin D25(OH)D concentrationCLIAenzyme-immunosorbent method
References
- Dusilová-Sulková S. Vitamin D metabolism and vitamin D traditional and nontraditional, target organs: implications for kidney patients. J Ren Care. 2009; 35 Suppl 1: 39–44.
- Pludowski P, Grant W, Bhattoa H, et al. Vitamin D Status in Central Europe. International Journal of Endocrinology. 2014; 2014: 1–12.
- Torun E, Gönüllü E, Ozgen IT, et al. Vitamin d deficiency and insufficiency in obese children and adolescents and its relationship with insulin resistance. Int J Endocrinol. 2013; 2013: 631845.
- Olson ML, Maalouf NM, Oden JD, et al. Vitamin D deficiency in obese children and its relationship to glucose homeostasis. J Clin Endocrinol Metab. 2012; 97(1): 279–285.
- Peterson C. Vitamin D deficiency and childhood obesity: interactions, implications, and recommendations. Nutrition and Dietary Supplements. 2015: 29.
- Bartoszewicz Z, Kondracka A, Bednarczuk T. Wysoka trwałość 25-hydroksy-witaminy D w próbkach surowicy przetrzymywanych w różnych warunkach podczas rutynowo wykonywanych pomiarów immunochemicznych. Diagn Lab. 2012; 48: 299–302.
- Szternel Ł, Odrowąż-Sypniewska G. Witamina D – standaryzacja oraz efekt terapeutyczny. Beckman Coulter Bliżej Ciebie. 2014; 1: 3–6.
- Kołłątaj W, Kołłątaj B, Klatka M, et al. Vitamin D – recommendations or the need for individualization of dosage? Pediatric Endocrinology. 2015; 14(1): 11–21.
- Odrowąż-Sypniewska G, Siódmiak J, Mańkowska-Cyl A. Comarision of two immunoassays for vitamin D measurement – is age a confounder? Standardy Med Pediatr. 2015; 12: 817–821.
- Engelman CD, Bo R, Zuelsdorff M, et al. Epidemiologic study of the C-3 epimer of 25-hydroxyvitamin D(3) in a population-based sample. Clin Nutr. 2014; 33(3): 421–425.
- Saida FB, Chen X, Tran K, et al. First 25-hydroxyvitamin D assay for general chemistry analyzers. Expert Rev Mol Diagn. 2015; 15(3): 313–323.
- Hsu SA, Soldo J, Gupta M. Evaluation of two automated immunoassays for 25-OH vitamin D: comparison against LC-MS/MS. J Steroid Biochem Mol Biol. 2013; 136: 139–145.
- Enko D, Kriegshäuser G, Stolba R, et al. Method evaluation study of a new generation of vitamin D assays. Biochem Med (Zagreb). 2015; 25(2): 203–212.
- Montgomery R. Standard Reference Materials; National Institute of Standards and Technology (Spotlight), 2010. https://www-s.nist.gov/srmors/certArchive.cfm.
- Johnson R. Assessment of ias with Emphasis on Method Comparison Clin Biochem Rev, 2008; 29: 37–42. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2556581/.
- McBride GA. proposal for strength-of-agreement criteria for Lin's Concordance Correlation Coefficient. NIWA Client Report. ; 2015: 1–14.
- Farrell CJL, Martin S, McWhinney B, et al. State-of-the-art vitamin D assays: a comparison of automated immunoassays with liquid chromatography-tandem mass spectrometry methods. Clin Chem. 2012; 58(3): 531–542.
- Lippi G, Salvagno GL, Fortunato A, et al. Multicenter Comparison of Seven 25OH Vitamin D Automated Immunoassays. J Med Biochem. 2015; 34(3): 344–350.
- Lensmeyer GL, Wiebe DA, Binkley N, et al. HPLC method for 25-hydroxyvitamin D measurement: comparison with contemporary assays. Clin Chem. 2006; 52(6): 1120–1126.
- Herrmann M, Harwood T, Gaston-Parry O, et al. A new quantitative LC tandem mass spectrometry assay for serum 25-hydroxy vitamin D. Steroids. 2010; 75(13-14): 1106–1112.
- Holick MF, Binkley NC, Bischoff-Ferrari HA, et al. Endocrine Society. Evaluation, treatment, and prevention of vitamin D deficiency: an Endocrine Society clinical practice guideline. J Clin Endocrinol Metab. 2011; 96(7): 1911–1930.