Evaluation of the Bosphore HBV Quantification Kit: Categorical and Quantitative Agreement with the Aptima HBV Quant Assay for HBV DNA Detection and Quantification

Accurate hepatitis B virus (HBV) DNA quantification is essential for assessing viral replication and monitoring antiviral therapy. This retrospective method-comparison study evaluated the Bosphore HBV Quantification Kit against the Aptima HBV Quant Assay using 130 residual anonymized EDTA-plasma specimens, comprising 110 comparator-positive and 20 comparator-negative samples. Categorical agreement was assessed using positive, negative, and overall percent agreement (PPA, NPA, and OPA), while quantitative agreement was evaluated using a predefined ±0.5 log10 IU/mL criterion, Bland–Altman analysis, Passing–Bablok regression, and Lin’s concordance correlation coefficient (CCC). PPA was 100% (110/110; 95% confidence interval [CI], 96.70–100.00%), NPA was 95.0% (19/20; 95% CI, 75.13–99.87%), and OPA was 99.23% (129/130; 95% CI, 95.79–99.98%). One confirmed qualitative discordance was observed. Overall, 109/110 paired numerical results (99.1%; 95% CI, 95.04–99.98%) were within ±0.5 log10 IU/mL. Bland–Altman analysis showed a mean bias of +0.124 log10 IU/mL, Passing–Bablok regression yielded Y = 0.107 + 1.019X, and Lin’s CCC was 0.991. The Bosphore assay demonstrated high categorical and quantitative agreement with the comparator across the HBV DNA concentration range evaluated, supporting its potential suitability for quantitative HBV DNA testing within the analytical workflow assessed in this study.