Quantitative hepatitis B surface antigen and hepatitis B e antigen titers
in prediction of treatment response to entecavir.
Lee JM, Ahn SH, Kim HS, Park H, Chang HY, Kim do Y, Hwang SG, Rim KS, Chon
CY, Han KH, Park JY.
Source
Department of Internal Medicine, Yonsei University College of Medicine,
Seoul, Korea; Department of Internal Medicine, CHA University, Seongnam-Si,
Korea.
Abstract
Quantitative hepatitis B surface antigen (qHBsAg) and quantitative
hepatitis B e antigen (qHBeAg) titers are emerging as useful tools for
measuring viral loads and for predicting the virological response (VR) and
serological response (SR) to pegylated interferon therapy. However, the
clinical utility of these assays in patients taking entecavir (ETV) is
largely unknown. Treatment-naive patients with chronic hepatitis B (CHB)
who were taking ETV for 2 years were enrolled. The qHBsAg and qHBeAg levels
were serially measured with the Architect assay. From 95 patients, 60.0% of
whom were hepatitis B e antigen-positive [HBeAg(+)], 475 samples were
analyzed. The median baseline log hepatitis B virus (HBV) DNA, log qHBsAg,
and log qHBeAg values were 6.73 copies/mL (4.04-9.11 copies/mL), 3.58 IU/mL
(1.17-5.10 IU/mL), and 1.71 Paul Ehrlich (PE) IU/mL (-0.64 to 2.63 PE
IU/mL), respectively. For the prediction of VR (HBV DNA < 60 copies/mL at
24 months) in HBeAg(+) patients, baseline alanine aminotransferase (P =
0.013), HBV DNA (P = 0.040), and qHBsAg levels (P = 0.033) were
significant. For the prediction of VR, the area under the curve for the
baseline log qHBsAg level was 0.823 (P < 0.001); a cutoff level of 3.98
IU/mL (9550 IU/mL on a nonlogarithmic scale) yielded the highest predictive
value with a sensitivity of 86.8% and a specificity of 78.9%. As for SR
(HBeAg loss at 24 months), the reduction of qHBeAg was significantly
greater in the SR(+) group versus the SR(-) group. The sensitivity and
specificity were 75.0% and 89.8%, respectively, with a decline of 1.00 PE
IU/mL at 6 months. With ETV therapy, the correlation between HBV DNA and
qHBsAg peaked at 6 months in HBeAg(+) patients. Conclusion: Both qHBsAg and
qHBeAg decreased significantly with ETV therapy. The baseline qHBsAg levels
and the on-treatment decline of qHBeAg in HBeAg(+) patients were proven to
be highly useful in predicting VR and SR, respectively. The determination
of qHBsAg and qHBeAg can help us to select the appropriate strategy for the
management of patients with CHB. However, the dynamic interplay between
qHBsAg, qHBeAg, and HBV DNA during antiviral therapy remains to be
elucidated. (Hepatology 2011;).