Development and evaluation of analytical performance of a fully automated chemiluminescent immunoassay for protein induced by vitamin K absence or antagonist II.

ABSTRACT

OBJECTIVES: Protein induced by vitamin K absence or antagonist II (PIVKA-II), an abnormal form of prothrombin, has been used as an aid in the diagnosis of hepatocellular cancer (HCC) as a tumor marker. We developed a fully automated quantitative immunoassay for PIVKA-II on the ARCHITECT® i systems. The aim of this study was to evaluate the analytical performance of this assay. DESIGN AND METHOD: Assay imprecision, sensitivity, dilution linearity, high dose hook effect, sample type equivalency, assay interferences of potential interfering materials and correlation with Picolumi PIVKA-II (Eidia, Tokyo, Japan) were evaluated. RESULTS: The percentage coefficient of variation (%CV) of total imprecision ranged from 2.8% to 5.4% with 10 levels of samples. The limit of blank (LoB), limit of detection (LoD), and limit of quantitation (LoQ) were less than 0.63 mAU/mL, 1.62 mAU/mL, and 8.25 mAU/mL, respectively. Linearity up to 30,000 mAU/mL, no high dose hook effect, no difference among sample types and no interference of common drugs and endogenous substances were observed. Correlation study with the Picolumi PIVKA-II gave a correlation coefficient of 0.93 and a regression slope of 1.07. CONCLUSIONS: The results demonstrate that the fully automated prototype ARCHITECT PIVKA-II assay is an accurate, highly sensitive and precise assay for the measurement of PIVKA-II levels in human sera and plasmas.