Article Figures & Data
Figures
- FIG. 1.
Quantification by the CAP/CTM v2.0 assay of HBV DNA levels in a commercial standard panel containing 2 × 102 (2.3 log10) to 2 × 107 (7.3 log10) IU of HBV DNA/ml (OptiQuant HBV DNA; AcroMetrix, Benicia, CA). The average measured values are shown as a function of the expected values (the actual HBV DNA contents of the panel members). The dashed line is the equality line.
- FIG. 2.
Correlation between the HBV DNA levels determined by the CAP/CTM v2.0 and bDNA assays (A) or by the CAP/CTM v2.0 and v1.0 assays (B) in 51 clinical samples (group C) containing HBV genotypes A (n = 12), B (n = 9), C (n = 8), D (n = 9), E (n = 10), and F (n = 3).
- FIG. 3.
(A) Bland-Altman plot of HBV DNA levels measured by the CAP/CTM v2.0 and bDNA assays in the 51 group B samples. The difference between the HBV DNA levels obtained by the CAP/CTM v2.0 assay and those obtained by the bDNA assay is plotted as a function of the mean of the two values. Different genotypes are represented by different colors. The shaded area corresponds to the mean difference ± 1.96 standard deviation. (B) Distribution of the differences between the HBV DNA levels obtained by the CAP/CTM v2.0 assay and those obtained by the bDNA assay for the same samples, according to the HBV genotype (genotypes A to E). The difference was not significant.
- FIG. 4.
Kinetics of HBV DNA levels measured in individual patients' plasma specimens with the CAP/CTM v1.0 assay (solid lines and open circles), the CAP/CTM v2.0 assay (solid lines and filled circles), and the bDNA assay (dashed lines). The top and bottom shaded areas correspond to the lower limits of detection of the bDNA (2.55 log10 IU/ml) and CAP/CTM v2.0 (1.30 log10 IU/ml) assays, respectively. HBV DNA levels (log10 IU/ml) are given on the y axis.
Tables
- TABLE 1.
Intra-assay (precision) and interassay reproducibility of the CAP/CTM v2.0 assay
Reproducibility Panel standard Control Target HBV DNA concn (log10 IU/ml) No. of determinations Mean (SD) concn of HBV DNA measured (log10 IU/ml) Coefficient of variation (%) Intra-assaya NAP-000 0.00 3 Target not detected NAP-HBV2E2 2.30 3 2.13 (0.02) 0.71 NAP-HBV2E3 3.30 3 3.17 (0.08) 2.67 NAP-HBV2E4 4.30 3 4.29 (0.01) 0.21 NAP-HBV2E5 5.30 3 5.06 (0.03) 0.55 NAP-HBV2E6 6.30 3 5.96 (0.02) 0.38 NAP-HBV2E7 7.30 3 6.94 (0.08) 1.22 Interassayb LPC Variable 18 2.45 (0.06) 2.25 HPC Variable 18 6.01 (0.04) 0.65 ↵ a For intra-assay reproducibility, the seven members of the standard panel (NAP-000 to NAP-HBV2E7), containing no HBV DNA or HBV DNA concentrations up to 2 × 107 IU/ml (i.e., 7.3 log10 IU/ml), respectively, were tested in triplicate in the same experiment.
↵ b For interassay reproducibility, the assay low-positive control (LPC) and high-positive control (HPC) were tested 18 times in different experiments. Two kit lots were used, with LPC values between 2.1 and 3.1 log10 IU/ml and between 2.0 and 3.0 log10 IU/ml, respectively, and with HPC values between 5.7 and 6.7 log10 IU/ml and between 5.5 and 6.5 log10 IU/ml, respectively.
- TABLE 2.
Mean differences between HBV DNA levels measured with the CAP/CTM v2.0 assay in 51 serum and 51 plasma specimens from the 16 patients with chronic HBV infection from group Da
HBV genotype No. of specimens Mean difference between HBV DNA levels ± SD (log10 IU/ml) A 16 0.11 ± 0.14 C 14 0.09 ± 0.17 D 5 0.09 ± 0.12 E 16 0.04 ± 0.16 ↵ a Four patients were infected with genotype A, 5 with genotype C, 1 with genotype D, and 6 with genotype E.
- TABLE 3.
Mean differences between HBV DNA levels measured with the CAP/CTM v1.0 and v2.0 assays in 51 plasma specimens from the 16 patients with chronic HBV infection from group Da
HBV genotype No. of specimens Mean difference between HBV DNA levels ± SD (log10 IU/ml) A 16 0.04 ± 0.24 C 14 0.10 ± 0.22 D 5 0.04 ± 0.05 E 16 0.20 ± 0.34 ↵ a Four patients were infected with genotype A, 5 with genotype C, 1 with genotype D, and 6 with genotype E.
