Background: Quantitation of serum hepatitis B virus (HBV) DNA has proven us
eful in assisting with patient management and treatment and several commerc
ially available assays have been developed to quantify serum HBV-DNA levels
.
Methods: The performance of the cross-linking assay and the branched-DNA si
gnal amplification (bDNA) assay for the quantitative measurement of HBV-DNA
was studied in 99 hepatitis B surface antigen-positive and viraemic patien
ts.
Results: Of these samples, 82 (83%) were positive for HBV-DNA by both assay
s and four (4%) were below the cut-off for bath assays. Of the remaining 13
samples, 10 contained measurable levels of HBV-DNA by the cross-linking as
say alone and three other samples contained measurable levels of HBV-DNA by
the bDNA assay alone. The sensitivity gain of the cross-linking assay rela
tive to bDNA assay in this study population was 10/92 (11%). In addition, a
linear regression analysis showed that the HBV-DNA levels obtained from bo
th assays was significantly correlated (gamma = 0.974, P < 0.0001).
Conclusions: These findings suggest that the recently developed cross-linki
ng assay is more sensitive than the bDNA assay for the quantitative determi
nation of HBV-DNA. (C) 1999 Blackwell Science Asia Pty Ltd.