Quantitation of hepatitis B surface antigen (HBsAg) is an increasingly popular method to determine the treatment response in chronic hepatitis B (CHB) patients. The clinical value of HBsAg level measurement during rescue therapy for lamivudine (LMV)-resistant CHB patients have not been evaluated to date. Therefore, this study investigated the correlation between HBsAg level and treatment response in LMV-resistant CHB patients treated with adefovir (ADV) add-on therapy.
LMV-resistant CHB patients treated with LMV-ADV combination therapy for over 2 years were included. HBsAg levels were measured at 6 month intervals until 1 year, and annually thereafter. Treatment response was assessed by determining the virological response (VR, undetectable HBV DNA levels) during treatment.
Fifty patients were included, of which 40 showed a VR. HBsAg levels were not different significantly at baseline (4.0 vs. 3.6 Log10 IU/mL,
The HBsAg level at 6 months after treatment can help predict treatment response.
Quantitation of hepatitis B surface antigen (HBsAg) is an increasingly popular method to determine the treatment response in chronic hepatitis B (CHB) patients. Measurement of serum HBsAg levels during treatment may help identify sustained responders to pegylated interferon therapy more reliably than measurement of serum hepatitis B virus (HBV) DNA
Therefore, this study investigated the correlation between the HBsAg level and treatment response in LMV-resistant CHB patients treated with adefovir (ADV) add-on therapy.
LMV-resistant CHB patients who were treated with LMV-ADV combination therapy for over 2 years at Konkuk University Medical Center were included in this study. Their medical records were reviewed, and their HBsAg levels were measured at 6 month intervals until 1 year, and annually thereafter. Data were censored if patients had a change in treatment, died due to liver-related or other causes, were lost to follow up, or underwent liver transplantation. The final follow up visit was in August 2012. The clinical diagnosis of liver cirrhosis was performed based on imaging findings, using modalities such as abdominal ultrasonography, computed tomography or magnetic resonance imaging, together with clinical findings consistent with liver cirrhosis such as esophageal or gastric varices, ascites, hepatic encephalopahy and thrombocytopenia.
All patients provided written informed consent for CHB treatment and the storage of remnant serum samples. This study was approved by the Institutional Review Board of Konkuk University Medical Center.
Serum samples were serially collected from each patient when rescue treatment with LMV-ADV combination was initiated and every 3 months thereafter; all samples were frozen and stored at -80℃.
HBsAg levels in the stored samples were measured at baseline, 6 months, and annually from 1 year to 5 years after treatment, using a chemiluminescent microparticle immunoassay (Architect HBsAg QT, Abbott Diagnostics, Chicago, IL, USA; Measurable range 0.05 - 250 IU/mL). HBsAg was quantified at a 1:500 dilution according to the manufacturer's instruction. To bring HBsAg levels within the measurable range, samples with above and below this range required a lower and higher dilution, respectively.
HBV DNA levels were also measured by using real-time polymerase chain reaction (PCR) (Cobas Amplicor PCR, Roche Molecular Systems, Inc., Branchburg, NJ, USA; lower detection limit, 20 IU/mL). Alanine aminotransferase (ALT), bilirubin, hepatitis B 'e' antigen (HBeAg) and antibody to HBeAg (anti-HBeAg) were measured.
Virological response (VR) was defined as undetectable HBV DNA by real-time PCR, and LMV-resistance was detected using restriction fragment mass polymorphism (RFMP) method, as described previously.
Continuous and categorical variables are expressed as means ± standard deviations and numbers (percentiles) respectively. The correlation between HBsAg and HBV DNA titers at baseline was analyzed by calculating Pearson's correlation coefficient. Groups were divided according to VR and compared using the chi-square test or Fisher's exact test for categorical variables and the Student
Fifty patients were included, of which 40 achieved virological response. All patients who did not achieve a VR were HBeAg positive (
HBsAg and HBV DNA levels were well correlated (r=0.531,
Baseline HBsAg levels were not different significantly between patients without a VR and those with a VR (4.0 vs. 3.6 Log10 IU/mL,
Thirty nine patients were HBeAg positive and 21 were negative. Twenty nine patients achieved VR within 1 year (eleven of HBeAg positive patients and eighteen patients of HBeAg negative patients). HBsAg level at baseline was not significantly different according to VR (3.6 vs. 3.9 Log10 copies/mL,
Thirty six patients achieved VR within 2 years (fifteen of HBeAg positive patients and all of HBeAg negative patients). HBsAg level was significantly lower in patients with VR at 6 months (3.3 vs. 3.8 Log10 IU/mL,
The AUROCs of HBsAg levels at 6 months, 1 year and 2 years were 0.770, 0.781, and 0.768, respectively (
CHB is an important cause of mortality and morbidity worldwide, accounting for up to 1 million deaths annually.
HBsAg has been the hallmark of HBV infection since the 1960s.
In the present study, HBeAg negative patients were all achieved VR within 2 years. Therefore, the value of HBsAg level is higher for HBeAg positive patients. In HBeAg positive patients, HBsAg level was not significantly different according to VR within 1 year, but HBsAg level at 6 months became significant in the analysis for VR within 2 years. We can assume that HBsAg level is more profit for prediction of long term treatment response in comparison with HBV DNA level.
Current treatment guidelines suggest ETV or tenofovir (TDF) as the first-line antiviral agent for the CHB treatment.
Many studies report a good correlation between HBsAg and HBV DNA levels in treatment-naïve CHB patients
In conclusion, HBsAg levels at 6 months of LMV-ADV combination therapy can help predict treatment response. More potent treatments should be considered for cases positive for HBeAg, with high baseline HBV DNA and high HBsAg levels after 6 months treatment.
No potential conflict of interest relevant to this article was reported.
hepatitis B surface antigen
chronic hepatitis B
lamivudine
adefovir
virological response
entecavir
polymerase chain reaction
alanine aminotransferase
hepatitis B 'e' antigen
restriction fragment mass polymorphism
Correlation between HBsAg and HBV DNA levels at baseline (A) Total patients. (B) HBeAg-positive patients. (C) HBeAg-negative patients.
On treatment HBsAg and HBV DNA change. (A) HBsAg level, (B) Reduction of HBsAg from baseline, (C) HBV DNA level, (D) Reduction of HBV DNA level from baseline.
Areas under the receiver operating characteristics curve (AUROCs) of HBsAg levels at each time point for virological response.
Kaplan-Meier curves of virological response with respect to HBsAg level 6 months.
Baseline characteristics
Variables | Virological response (+) (n=40) | Virological response (-) (n=10) | |
---|---|---|---|
Male (n, %) | 25 (62.5%) | 3 (30.0%) | 0.084 |
Age (years) |
44.4±13.6 | 48.5±12.9 | 0.396 |
Cirrhosis (n, %) | 11 (27.5%) | 4 (40.0%) | 0.462 |
Duration (month) |
|||
LMV | 28.8±20.0 | 35.7±34.6 | 0.559 |
LMV+ADV | 45.8±10.1 | 42.6±7.7 | 0.355 |
HBeAg positive (n, %) | 19 (47.5%) | 10 (100%) | 0.003 |
HBV DNA (log10 IU/mL) |
6.7±1.2 | 7.7±1.1 | 0.027 |
HBsAg (log10 IU/mL) |
3.6±0.6 | 4.0±0.7 | 0.072 |
ALT (IU/mL) |
263.9±349.7 | 75.8±112.8 | 0.102 |
Albumin (mg/dL) |
4.3±0.3 | 4.4±0.2 | 0.251 |
Total bilirubin (IU/mL) |
1.0±0.5 | 0.8±0.3 | 0.179 |
Prothrombin time (INR) |
1.1±0.1 | 1.1±0.1 | 0.400 |
Child-Pugh score |
5.1±0.4 | 5.0±0.0 | 0.058 |
Resistance mutation (n, %) | 0.198 | ||
M204I | 15 (37.5%) | 2 (20.0%) | |
M204V | 1 (2.5%) | 0 (0%) | |
L180M+M204I | 13 (32.5%) | 3 (30.0%) | |
L180M+M204V | 9 (22.5%) | 2 (20.0%) | |
L180M+M204IV | 2 (5.0%) | 3 (30.0%) |
Mean±standard deviation.
LMV, lamivudine; ADV, adefovir; HBV, hepatitis B virus; HBeAg, hepatitis B envelope antigen; HBsAg, hepatitis B surface antigen; ALT, alanine aminotransferase; INR, international normalized ratio.
Comparison of HBsAg levels (log10 IU/mL) and HBV DNA levels (log10 IU/mL) between groups
Time | HBsAg levels |
Reduction in HBsAg levels from baseline |
||||
---|---|---|---|---|---|---|
Virological response (+) | Virological response (-) | Virological response (+) | Virological response (-) | |||
0 month |
3.6±0.6 | 4.0±0.7 | 0.072 | |||
6 months |
3.3±0.5 | 3.9±0.5 | 0.002 | 0.3±0.6 | 0.2±0.4 | 0.384 |
1 year | 3.2±0.5 | 3.8±0.5 | 0.004 | 0.4±0.6 | 0.3±0.5 | 0.479 |
2 years |
3.2±0.7 | 3.9±0.6 | 0.008 | 0.5±0.6 | 0.2±0.5 | 0.247 |
3 years |
3.1±0.8 | 3.7±0.5 | 0.020 | 0.6±0.6 | 0.4±0.6 | 0.556 |
0 month |
6.7±1.2 | 7.7±1.1 | 0.026 | |||
6 months |
2.6±1.0 | 4.9±0.7 | <0.001 | 4.1±1.3 | 2.8±0.9 | 0.001 |
1 year |
2.4±1.0 | 4.5±0.4 | <0.001 | 4.3±1.2 | 3.3±0.9 | 0.013 |
2 years |
1.3±1.2 | 4.0±0.4 | <0.001 | 5.5±1.6 | 3.8±1.1 | 0.004 |
3 years |
1.0±1.2 | 3.5±0.6 | <0.001 | 5.9±1.7 | 4.2±1.4 | 0.006 |
Mean±standard deviation
HBV, hepatitis B virus; HBsAg, hepatitis B surface antigen.
Comparison of HBsAg levels (log10 IU/mL) and HBV DNA levels (log10 IU/mL) according to virological response within 1 year and 2 year
Virological response within 1 year | Total |
HBeAg positive |
HBeAg negative |
||||||
---|---|---|---|---|---|---|---|---|---|
Positive (n=29) | Negative (n=21) | Positive (n=11) | Negative (n=18) | Positive (n=18) | Negative (n=3) | ||||
0 month | |||||||||
HBsAg |
3.6±0.7 | 3.9±0.6 | 0.106 | 4.0±0.6 | 3.9±0.6 | 0.724 | 3.4±0.7 | 3.9±0.3 | 0.049 |
HBV DNA |
6.6±1.3 | 7.3±1.1 | 0.058 | 7.3±1.3 | 7.2±1.2 | 0.883 | 6.2±1.2 | 8.0±0.2 | 0.025 |
6 months | |||||||||
HBsAg |
3.3±0.5 | 3.6±0.6 | 0.044 | 3.4±0.5 | 3.7±0.6 | 0.129 | 3.2±0.5 | 3.1±0.8 | 0.721 |
HBV DNA |
2.3±0.9 | 4.2±1.0 | <0.001 | 2.4±0.9 | 4.3±1.0 | <0.001 | 2.2±0.9 | 3.3±0.8 | 0.059 |
1 year | |||||||||
HBsAg |
3.2±0.6 | 3.6±0.4 | 0.006 | 3.3±0.5 | 3.7±0.4 | 0.052 | 3.1±0.6 | 3.1±0.1 | 0.921 |
HBV DNA |
2.1±0.9 | 3.9±0.8 | <0.001 | 2.2±0.7 | 3.9±0.8 | <0.001 | 2.0±0.9 | 3.7±0.8 | 0.007 |
0 month | N.A | ||||||||
HBsAg |
3.6±0.7 | 4.0±0.6 | 0.102 | 4.0±0.6 | 4.0±0.6 | 0.834 | 3.4±0.7 | ||
HBV DNA |
6.8±1.3 | 7.4±1.2 | 0.172 | 7.3±1.1 | 7.4±1.2 | 0.906 | 6.5±1.3 | ||
6 months | |||||||||
HBsAg |
3.3±0.5 | 3.8±0.5 | 0.001 | 3.4±0.5 | 3.8±0.5 | 0.026 | 3.2±0.6 | ||
HBV DNA |
2.6±0.9 | 4.7±0.8 | <0.001 | 3.0±0.7 | 4.7±0.8 | <0.001 | 2.4±1.0 | ||
1 year | |||||||||
HBsAg |
3.2±0.6 | 3.7±0.4 | 0.005 | 3.4±0.6 | 3.7±0.4 | 0.127 | 3.1±0.5 | ||
HBV DNA |
2.4±0.9 | 4.3±0.5 | <0.001 | 2.6±0.3 | 4.3±0.5 | <0.001 | 2.2±1.1 | ||
2 years | |||||||||
HBsAg |
3.2±0.7 | 3.8±0.6 | 0.008 | 3.5±0.6 | 3.8±0.6 | 0.164 | 3.0±0.7 | ||
HBV DNA |
1.2±1.1 | 3.7±1.1 | <0.001 | 1.5±1.1 | 3.7±1.1 | <0.001 | 1.0±1.1 |
Mean±standard deviation.
HBV, hepatitis B virus; HBeAg, hepatitis B envelope antigen; HBsAg, hepatitis B surface antigen.
Pairwise comparison of AUROCs (HBsAg level for virological response)
Difference between areas | Standard error | 95% Confidence interval | ||
---|---|---|---|---|
6 month vs. 1 year | 0.0108 | 0.0527 | -0.0925 to 0.114 | 0.8375 |
6 month vs. 2 year | 0.0027 | 0.0511 | -0.0974 to 0.103 | 0.9578 |
1 year vs. 2 year | 0.0135 | 0.0463 | -0.0772 to 0.104 | 0.7703 |
HBsAg, hepatitis B surface antigen.
DeLong’s test.