Jenna Weber1, Malaya K Sahoo1, Nathaniel Taylor2, Eirene Uy2, Run-Zhang Shi1, Benjamin A Pinsky3,2,4. 1. Department of Pathology, Stanford University School of Medicine, Stanford, CA. 2. Clinical Virology Laboratory, Stanford Health Care, Stanford, CA. 3. Department of Pathology, Stanford University School of Medicine, Stanford, CA; bpinsky@stanford.edu. 4. Department of Medicine, Division of Infectious Diseases and Geographic Medicine, Stanford University School of Medicine, Stanford, CA.
Abstract
BACKGROUND: The quantification of hepatitis B (HBV) DNA in serum is critical to identify patients requiring antiviral therapy and to monitor the response to treatment. METHOD: This study describes the evaluation of the Aptima HBV Quant Dx assay (Aptima HBV) performed on the automated Panther system. RESULTS: Aptima HBV was linear from 1.70 to 7.70 log10 IU/mL with a commercial reference panel, as well as clinical specimens representing genotypes B and C, and total imprecision, as measured by the percentage coefficient of variation (%CV) at 2.0 log10 IU/mL was <10%. The specificity of Aptima HBV was 94.7% (126/133) and 96.6% (84/87) for serum specimens from individuals without HBV exposure and individuals with resolved HBV infection, respectively. The qualitative agreement and quantitative accuracy of Aptima HBV was compared to the COBAS AmpliPrep/COBAS TaqMan HBV Test v2.0 (CAP/CTM). Overall agreement was 90.8% (187/206) with a κ statistic of 0.708 (standard error, 0.063; 95% CI, 0.585-0.831). Passing-Bablok regression revealed a regression line of y = 0.953x + 0.075 (95% CI of the slope, 0.883-1.011; intercept, -0.100 to 0.299), and Bland-Altman analysis (Aptima - CAP/CTM) showed a slight negative bias (-0.054 log10 IU/mL, and 95% limits of agreement of -1.093 to 0.984). CONCLUSIONS: The Aptima HBV test affords a suitable alternative to CAP/CTM for serum virus load testing and provides a key component of the diagnostic algorithm for the global eradication of viral hepatitis.
BACKGROUND: The quantification of hepatitis B (HBV) DNA in serum is critical to identify patients requiring antiviral therapy and to monitor the response to treatment. METHOD: This study describes the evaluation of the Aptima HBV Quant Dx assay (Aptima HBV) performed on the automated Panther system. RESULTS: Aptima HBV was linear from 1.70 to 7.70 log10 IU/mL with a commercial reference panel, as well as clinical specimens representing genotypes B and C, and total imprecision, as measured by the percentage coefficient of variation (%CV) at 2.0 log10 IU/mL was <10%. The specificity of Aptima HBV was 94.7% (126/133) and 96.6% (84/87) for serum specimens from individuals without HBV exposure and individuals with resolved HBV infection, respectively. The qualitative agreement and quantitative accuracy of Aptima HBV was compared to the COBAS AmpliPrep/COBAS TaqMan HBV Test v2.0 (CAP/CTM). Overall agreement was 90.8% (187/206) with a κ statistic of 0.708 (standard error, 0.063; 95% CI, 0.585-0.831). Passing-Bablok regression revealed a regression line of y = 0.953x + 0.075 (95% CI of the slope, 0.883-1.011; intercept, -0.100 to 0.299), and Bland-Altman analysis (Aptima - CAP/CTM) showed a slight negative bias (-0.054 log10 IU/mL, and 95% limits of agreement of -1.093 to 0.984). CONCLUSIONS: The Aptima HBV test affords a suitable alternative to CAP/CTM for serum virus load testing and provides a key component of the diagnostic algorithm for the global eradication of viral hepatitis.