MULTICENTER COMPARISON OF SEVEN 25OH VITAMIN D AUTOMATED IMMUNOASSAYS

作者:Lippi Giuseppe*; Salvagno Gian Luca; Fortunato Antonio; Dipalo Mariella; Aloe Rosalia; Da Rin Giorgio; Giavarina Davide
来源:Journal of Medical Biochemistry, 2015, 34(3): 344-350.
DOI:10.2478/jomb-2014-0054

摘要

Background: The measurement of 25OH vitamin D continues to grow in clinical laboratories. The aim of this multicenter study was to compare the results of seven automated commercial immunoassays with a reference HPLC technique. Methods: One hundred and twenty consecutive outpatient serum samples were centrifuged, divided in aliquots, frozen and shipped to the participating laboratories. 25OH Vita min D was measured with a reference HPLC system and with seven automated commercial immunoassays (Roche Cobas E601, Beckman Coulter Unicel DXI 800, Ortho Vitros ES, DiaSorin Liaison, Siemens Advia Centaur, Abbott Architect i System and IDS iSYS). Results: Compared to the reference method, the regression coefficients ranged from 0.923 to 0.961 (all p < 0.001). The slope of Deming fit ranged from 0.95 to 1.06, whereas the intercept was comprised between -15.2 and 9.2 nmol/L. The bias from the reference HPLC technique varied from -14.5 to 8.7 nmol/L. The minimum performance goal for bias was slightly exceeded by only one immunoassay. The agreement between HPLC and the different immunoassays at 50 nmol/L 25OH Vitamin D varied between 0.61 and 0.85 (all p < 0.001). The percentage of samples below this cut-off was significantly different with only one immunoassay. Conclusions: The excellent correlation with the reference HPLC technique attests that all seven automated immuno assays may be reliably used for routine assessment of 25OH-D in clinical laboratories. The significant bias among the different methods seems mostly attributable to the lack of standardization and calls for additional efforts for improving harmonization of 25OH-D immunoassays.

  • 出版日期2015-7