Performance of Cobas e801 for detection of serum prothrombin induced by vitamin K absence-II in hepatocellular carcinoma: A comparative study

Objective Prothrombin induced by vitamin K absence-II (PIVKA-II) is a biomarker for diagnosing hepatocellular carcinoma (HCC). We compared the analytical performance of three immunoassay systems—Cobas e801 (Roche Diagnostics, Mannheim, Germany), Architect i2000 (Abbott Diagnostics, Abbott Park, USA), and Lumipulse G1200 (Fujirebio Diagnostics, Tokyo, Japan)—and conducted an exploratory evaluation of their potential clinical utility in different patient groups. Methods A total of 887 serum samples were collected from patients with HBV-related HCC, those with colorectal cancer (CRC), and healthy individuals. We assessed the precision and linearity of each instrument, and examined instrument correlation and agreement at a clinical diagnostic threshold of 40 mAU/mL. Moreover, we explored the distribution of PIVKA-II levels across these groups. Additionally, we performed an imaging-based analysis to observe any discrepancies in detecting HCC. Results All three instruments demonstrated good precision (coefficients of variation <5%) and excellent linearity (coefficient of determination >0.99). Cobas e801 measured proportionally lower PIVKA-II levels, but exhibited strong concordance with the 40 mAU/mL cut-off, indicating fewer false positives in CRC and healthy cohorts. In an exploratory imaging-based assessment, the three instruments displayed similar performance in identifying HCC, although Cobas e801's cut-off level of 24.5 mAU/mL increased sensitivity at the expense of slightly reduced accuracy. Conclusions Cobas e801 demonstrated acceptable analytical performance, comparable to Architect i2000 and Lumipulse G1200. Lowering its cut-off level may boost sensitivity in high-prevalence areas. Prospective studies are needed to clarify clinical applicability.