INTRODUCTION: The increasing clinical significance of 25-Hydroxy-Vitamin D (25(OH)D) has made it an indispensable test in the laboratory. The aim of this study was to investigate the analytical performance of two immunoassay methods, the Abbott product Architect 25-OH Vitamin D test and the Beckman Coulter product Access 25 (OH) Vitamin D total test that is used widely.
METHODS: Architect i2000SR System (Abbott Laboratories, IL, USA. ref: 5P02) and Access2 (Beckman Coulter, Brea, CA, USA. ref: B24838) immunoassay systems were compared in terms of accuracy, linearity, limit of blank (LoB), limit of detection (LoD), limit of quantification (LoQ) and precision, and method comparison was performed in 96 serum samples. Deming regression analysis and Bland Altman graphs were used in method comparisons.
RESULTS: Architect's and Access2s within run variability coefficients (%CV) were found smaller than 3.1%, 6.72%, respectively. The 25(OH)D measurement for Architect and Access2 showed good linearity in 98.9-114% and 94.1-103.5% convenience at concentrations of 5-160 ng/mL and 6.2-210.4 ng/mL, respectively. When the Access2 and Architect were compared, the correlation coefficient (R) was found to be 0.921 (y = -2.1 + 0.97x).
DISCUSSION AND CONCLUSION: In our study, the revised 5P02 Abbott Architect 25(OH)D and Beckman Coulter Access2 25(OH)D total test were shown to have the proper analytical value by verifying the total test.