Background: To compare four automated immunoassays for the measurement of 25(OH)-vitamin D (25-OHD) and to assess the impact on the results obtained from a healthy population.
Methods: We analysed 100 serum samples on Unicel DxI 800 (Beckman Coulter), Architect i1000 (Abbott), Cobas e411 (Roche) and Liaison XL (DiaSorin). Passing-Bablok regression and Bland-Altman plots were used for method comparison. In order to categorise the obtained values, results were categorised into the following groups: 0-25 nmol/L, 25-50 nmol/L, 50-75 nmol/L and above 75 nmol/L and compared. The percentage of samples below 75 nmol/L, and below 50 nmol/L was then calculated for every method.
Results: According to paired comparisons, each method differs from others (p<0.0001) except Cobas vs Architect, which do not show a statistically significant difference (p=0.39). The strongest correlation was found between Liaison and Architect (ρ=0.94, p<0.0001). The percentage of samples below the recommended value of 75 nmol/L were: 70% (Architect), 92% (Liaison), 71% (Cobas) and 89% (Unicel). The percentage of samples below the value of 50 nmol/L were: 17% (Architect), 55% (Liaison), 28% (Cobas) and 47% (Unicel).
Conclusions: The observed differences stem from the use of different analytical systems for 25-OHD concentration analysis and can result in different outcomes. The recommended values should be established for each assay in accordance with the data provided by the manufacturer or in the laboratory, in accordance with proper standardisation.
Uvod: Cilj je bio da se uporede četiri automatizovana imunotesta za merenje 25(OH)-vitamina D (25-OHD) i da se proceni uticaj na rezultate dobijene na uzorku zdrave populacije.
Metode: Analizirali smo 100 uzoraka seruma na analizatorima Unicel DxI 800 (Beckman Coulter), Architect i1000 (Abbott), Cobas e411 (Roche) i Liaison KSL (DiaSorin). Za upoređivanje metoda su korišćene Passing-Bablok-ova regresija i Bland-Altman-ovi plotovi. Da bi se dobijene vrednosti kategorizovale, rezultati su kategorisani u sledeće grupe: 0-25 nmol/L, 25-50 nmol/L, 50-75 nmol/L i iznad 75 nmol/L i posle toga upoređeni. Potom je izračunat procenat uzoraka ispod 75 nmol/L i ispod 50 nmol/L za svaku metodu.
Rezultati: Prema uparenim poređenjima, svaka metoda se razlikuje od ostalih (p <0,0001), osim u slučaju kada se porede rezultati analizatora Cobas i Architect, koji ne pokazuju statistički značajnu razliku (p = 0,39). Najsnažnija korelacija je uočena između Liason i Architect (ρ = 0,94, p <0,0001). Procenat uzoraka ispod preporučene vrednosti od 75 nmol/L je bio: 70% (Architect), 92% (Liaison), 71% (Cobas) i 89% (Unicel). Procenat uzoraka ispod vrednosti od 50 nmol/L je bio: 17% (Architect), 55% (Liaison), 28% (Cobas) i 47% (Unicel).
Zaključak: Uočene razlike potiču od upotrebe različitih analitičkih sistema za analizu koncentracije 25-OHD i mogu da rezultiraju različitim ishodima. Preporučene vrednosti treba da budu utvrđene za svaki test u skladu sa podacima koje je dostavio proizvođač ili u laboratoriji, u skladu sa odgovarajućom standardizacijom.
Keywords: 25(OH)-vitamin D; Architect; Cobas; Liaison; Unicel; method comparison; vitamin D.
2021 Jindra Windrichova, Pavel Broz, Radka Fuchsova, Ondrej Topolcan, Ladislav Pecen, Otto Mayer, Radek Kucera, published by CEON/CEES.