Assay Performance Verification and Reference Interval Establishment for PIVKA-II on the Roche cobas e 801

Objectives: This study aimed to validate the analytical performance of Roche cobas e 801 chemiluminescent immunoassay for Protein Induced by Vitamin K Absence II (PIVKA-II) and establish age-/sex-specific reference intervals. Methods: Precision (intra-lot/inter-lot coefficients of variation), linearity (0-1,200 ng/mL range), and clinical reportable range (80-120% recovery criteria) were validated following CLSI guidelines. Method comparison with Abbott Alinity i employed Bland-Altman analysis and Kendall’s Tau correlation. Age-/sex-specific reference intervals were derived from 2,253 subjects, with validation against manufacturer-provided thresholds. Results: The system demonstrated intra-lot CVs of 1.36-1.57% and inter-lot CVs of 1.13-1.16%. Linear regression analysis showed Y = 0.987X + 6.3458 (R²=0.9991) with 89.62-92.16% recovery rates. Reference Interval Validation: PIVKA-II levels in 20 healthy adult serum samples ranged from 12.2 to 22.3 ng/mL, all below the manufacturer’s reference interval of <28.4 ng/mL, confirming 100% compliance. Method comparison revealed 96.5% inter-system agreement (Kendall’s Tau=0.774, p<0.05). The reference intervals for PIVKA-II were established. The interval for males (2.5th–97.5th percentile) was 9.71–28.99 ng/mL. In females, reference intervals varied by age group: 9.30–24.20 ng/mL for ages 18–39 years, 9.76–27.28 ng/mL for ages 40–59 years, and 8.70–29.81 ng/mL for those aged ≥60 years.Conclusion: The PIVKA-II on the Roche cobas e 801 system demonstrated excellent analytical performance, meeting all quality requirements of our laboratory and fulfilling the needs of clinical applications. Additionally, the establishment of age- and sex-specific reference intervals for PIVKA-II in a local healthy population provides valuable insights for clinical diagnosis and interpretation of test results.