Verification of Ferritin Assay Methods Evaluation of Analytical Performance by Immunometric Method

Introduction: Ferritin is required for the diagnosis of diseases affecting iron metabolism, such as hemochromatosis and iron deficiency anemia. Verification/validation of the in vitro assay method consists in assessing the performance of the analytical process, then comparing it with the criteria in NF EN ISO 15189. The aim was to evaluate the analytical performance of the sandwich chemiluminescence immunometric ferritin assay on a Maglumi® X3 analyzer.  Materials and Methods: Verification of the ferritin assay on SNIBE's Maglumi® X3 analyzer was based on the methods recommended in the Valtec protocol and the GTA-SH 04 technical guide for human health accreditation, for assessing the analytical performance of analyzers for quantitative analysis methods on two different kits from the same batch. The performances tested were repeatability, reproducibility, and inter-sample contamination. Data were processed using method validation software, Microsoft Office Excel and SPSS V20 at 5% risk.  Results: Repeatability quantifying precision and reproducibility quantifying intermediate precision in the first kit were satisfactory, with CV values of 2.16% and 1.82% respectively for the mean level (CIQ Ferritin Target=58.2 ± 5.83 μg/L). For the second Kit, the CV values were 0.60% and 1.05% respectively for the same average level. Supplier CVs were in the order of 3.60% and 5.32%, while SFBC CVs were in the order of 6% and 8% respectively. Inter-sample contamination was deemed satisfactory for routine use of the analyzer.  Conclusion: The analyzer tested meets the analytical performance requirements for the reliable determination of ferritin by sandwich chemiluminescence immunometry on a Maglumi® X3 analyzer.