Biological variation of PIVKA-II in blood serum of healthy subjects measured by automated electrochemiluminescent assay

Background: Prothrombin/Protein Induced by Vitamin K Absence-II (PIVKA-II) is a candidate biomarker of hepatocellular cancer, recommended both for diagnostics and monitoring. The aim was to evaluate biological variation (BV) of serum PIVKA-II. Methods: Within-subject (CV I ) and between-subject (CV G ) BV estimates were assessed in 14 healthy volunteers in a 6-week protocol. Serum concentrations of PIVKA-II were measured by a Roche Elecsys PIVKA-II diagnostic kit (cobas e8000). Precision (CV A ) was assessed from duplicate measurements of all volunteers ' samples. Two methods were used for the estimation of CV I : SDANOVA and CV-ANOVA method. We calculated the index of individuality (II) and reference change value. The experiment was fully compliant with EFLM database checklist. Results: The CV I of PIVKA-II in healthy persons, as calculated by two statistical methods, were 8.2% (SD-ANOVA with CV A of 3.2%) and 9.4% (CV-ANOVA) with CV A of 2.7%). The CV G was 19.5% (SD-ANOVA), and respective II and RCV were 0.42 and 24.4%. Conclusions: CV I and CV G of PIVKA-II were 8.2% and 19.5%, respectively, with CV A below 4%. The low II and RCV below 25% enable the use of this biomarker both for diagnostics and monitoring. More data are needed before the introduction of PIVKA-II into clinical practice.