Background Vitamin D detection has attracted more and more attention worldwide. Automatic immunoassays are the most widely used methods for clinical 25-hydroxyvitamin D (25(OH)D) testing. However, the comparability between the results of different immunoassays is a practical problem that perplexes clinical interpretation.
Objective To evaluate the consistency of Snibe (Maglumi 4000 plus) and DiaSorin (Liaison XL) in automatic 25(OH)D immunoassays.
Methods A total of 810 serum samples were collected from healthy subjects in the Second Medical Center of Chinese PLA General Hospital from May to June in 2019, and 25(OH)D was detected by Snibe and DiaSorin immunoassays, respectively. DiaSorin was performed as the comparative method, the variation trend of detection deviation of Snibe and DiaSorin with the increase of 25(OH)D concentration was analyzed. The correlation and consistency of the two methods were analyzed by passing-bablok regression and intraclass correlation coefficient (ICC), and the consistency of the two methods in clinical judgment of vitamin D nutritional status was analyzed by Kappa test.
Results The average deviation between the two methods was −1.39 ng/mL (−1.06%). Within a certain range, the detection deviation increased with the increase of 25(OH)D concentration. Slope from regression of the two methods was 0.650 (95% CI: 0.623 − 0.680), while the intercept was 4.871 (95% CI: 4.396 − 5.338), and the ICC was 0.766 (95% CI: 0.700 − 0.814). The concordance rate in judgment of vitamin D nutritional status was 68.77%, and the Kappa value was 0.479.
Conclusion Snibe and DiaSorin automatic 25(OH)D immunoassays show good correlation and agreement. A specific reference range for each 25(OH)D immunoassay is needed in clinical judgment of vitamin D status.
DownLoad: