Serum hepatitis B surface antigen (HBsAg) kinetics in hepatitis B e antigen (HBeAg)-negative chronic hepatitis B

ALT to qHBsAg ratio predicts long-term HBsAg seroclearance after entecavir cessation in Chinese patients with chronic hepatitis B

BACKGROUND & AIMS

Factors predicting HBsAg seroclearance after treatment cessation, irrespective of nucleos(t)ide analogue (NA) resumption, have important clinical implications. We evaluated predictors of long-term HBsAg seroclearance after entecavir cessation.

METHODS

This study followed-up Chinese patients with chronic hepatitis B from two previous studies of entecavir cessation. All patients were non-cirrhotic, HBeAg-negative, with undetectable HBV DNA (<20 IU/ml) at end-of-treatment (EOT). They were monitored closely for 48 weeks with regular HBV DNA, quantitative HBsAg (qHBsAg) and alanine aminotransferase (ALT) measurements. Entecavir was resumed at HBV DNA >2,000 IU/ml, irrespective of ALT levels. After the initial 48 weeks, patients were assessed every 6 months, regardless of entecavir resumption, to monitor for HBsAg seroclearance.

RESULTS

A total of 194 patients (63.4% male, mean age 49.9 years, on entecavir for a median of 47.2 months) were recruited; 94 (48.5%) and 158 (81.4%) patients had EOT qHBsAg <100 IU/ml and <1,000 IU/ml, respectively; 151 (77.8%) patients were eventually resumed on entecavir. After follow-up for a median of 70.7 (51.0-118.2) months, 28 (14.4%) patients had HBsAg seroclearance. qHBsAg levels at weeks 36 and 48 after EOT independently predicted HBsAg seroclearance (both p <0.01), whereas qHBsAg from EOT to week 24 only trended towards statistical significance. The ratio of ALT/qHBsAg at all time points from EOT to week 48 independently predicted HBsAg seroclearance (hazard ratios ranging from 1.003-1.028, all p <0.01) with excellent diagnostic performance (area under the receiver-operating characteristic curve 0.799-0.933, negative predictive value >90% at different time points), regardless of whether entecavir was resumed.

CONCLUSIONS

The ALT/qHBsAg ratio after entecavir cessation predicts HBsAg seroclearance, even in patients who were resumed on treatment. Its use may mitigate the risk of severe hepatitis flares in patients managed by observation without treatment resumption.

IMPACT AND IMPLICATIONS

Current predictors of HBsAg seroclearance after finite nucleos(t)ide analogue (NA) therapy have suboptimal predictive value. We demonstrated that the ALT/qHBsAg ratio may be able to reflect the balance between host control and virological activity. The ALT/qHBsAg ratio at different time points from end-of-treatment till week 48 independently and accurately predicted HBsAg seroclearance in patients who have stopped entecavir. The ALT/qHBsAg ratio may be utilized by clinicians for patient selection and retreatment decisions in finite NA therapy.

Comparison of the Effect of Entecavir and Tenofovir on Serum HBsAg Levels in Chronic HBe-Negative Hepatitis B Patients

Background: The quantification of hepatitis B surface antigen (qHBsAg) was proposed as a helpful tool to monitor treatment efficacy with nucleos(t)ide analogs (NA) in HB e antigen-negative chronic HB. Objectives: The present study aimed to assess the effect of entecavir (ETV) and tenofovir dipivoxil (TDF) on qHBsAg kinetics and estimate the time necessary to achieve HBsAg clearance with each of these drugs. Methods: The study was conducted on 93 patients, 54 and 39 of whom were treated with ETV and TDF for a median time of 42 months, respectively. The qHBsAg was measured in 6-month intervals with the Elecsys HBsAg II Quantitative assay. The estimated time to undetectable HBsAg was calculated using the best-fitted curve analysis. Results: There was a significant decrease in qHBsAg titers in 79 (84.9%) patients with no difference between ETV and TDF groups (P = 0.754). The median quantitative HBsAg drop was 2003 IU/mL (interquartile range: 638.1 - 5010). The HBsAg levels decreased by 40.3 ± 25.9% on average. The expected time required for HBsAg clearance was comparable in both groups, equaling 104 and 114 months for TDF and ETV, respectively. Conclusions: The HBsAg clearance can be achieved in a substantial proportion of patients after additional 5 years of treatment with NA. The potency of TDF and ETV in qHBsAg reduction is similar.

No influence of hepatic steatosis on the 3-year outcomes of patients with quiescent chronic hepatitis B

The influence of hepatic steatosis on the natural history of chronic hepatitis B (CHB) virus is unclear. Therefore, we investigated whether concurrent steatosis in patients with CHB influences the probability of hepatitis B surface antigen (HBsAg) loss, fibrosis progression and hepatocellular carcinoma (HCC) development. This study enrolled treatment-naïve patients with virologically (HBV DNA <2,000 IU/ml) and biochemically (alanine aminotransferase level <40 IU/L) quiescent CHB who underwent transient elastography between January 2004 and December 2015 and completed 3 years of follow-up. RESULTS: The mean age of the study population (n = 720) was 52.0 years, and there were more men than women (n = 419, 58.2%). The mean HBV DNA level was 321.6 IU/ml. During the 3-year period, 74 (10.3%) patients achieved HBsAg seroclearance. Lower HBV DNA levels (hazard ratio = 0.995, p < .05) were independently associated with HBsAg seroclearance, while hepatic steatosis was not (p > .05). Fibrosis progressed in 89 (12.4%) patients. Male gender (odds ratio [OR] = 1.720) and higher body mass index (OR = 1.083) were independently associated with an increased probability of fibrosis progression (all p < .05), while higher total cholesterol levels (OR = 0.991) and higher liver stiffness values (OR = 0.862) were independently associated with a decreased probability of fibrosis progression (all p < .05). HCC developed in 46 (6.4%) patients. Male gender (OR = 3.917) and higher AST levels (OR = 1.036) were independently associated with an increased probability of HCC development (p < .05). Hepatic steatosis was not associated with the probability of HBsAg seroclearance, fibrosis progression or HCC development in patients quiescent CHB in our study. Further studies with longer follow-up periods are required to validate our findings.

Diverse effects of hepatic steatosis on fibrosis progression and functional cure in virologically quiescent chronic hepatitis B

BACKGROUND & AIMS

Concomitant non-alcoholic fatty liver disease is common in patients with chronic hepatitis B (CHB) infection, although its impact on liver-related outcomes remains controversial. We aimed to study the effect of hepatic steatosis on the risk of fibrosis progression and the likelihood of HBsAg seroclearance.

METHODS

Treatment-naïve patients with CHB, normal alanine aminotransferase and low viraemia (serum HBV DNA <2,000 IU/ml) were prospectively recruited for baseline and 3-year transient elastography assessment. Fibrosis staging was defined according to the EASL-ALEH guidelines, with fibrosis progression defined as ≥1 stage increment of fibrosis. Hepatic steatosis and severe hepatic steatosis were defined as controlled attenuation parameter (CAP) ≥248 dB/m and ≥280 dB/m, respectively.

RESULTS

A total of 330 patients (median age 50.5 years, 41.2% male, median HBV DNA 189 IU/ml) were recruited. Twenty-two patients (6.7%) achieved HBsAg seroclearance during follow-up, and the presence of hepatic steatosis was associated with a significantly higher chance of HBsAg seroclearance (hazard ratio 3.246; 95% CI 1.278-8.243; p = 0.013). At baseline, 48.8% and 28.8% of patients had steatosis and severe steatosis, respectively, while 4.2% had F3/F4 fibrosis at baseline, increasing to 8.7% at 3 years. The rate of liver fibrosis progression in patients with persistent severe steatosis was higher than in those without steatosis (41.3% vs. 23%; p = 0.05). Persistent severe hepatic steatosis was independently associated with fibrosis progression (odds ratio 2.379; 95% CI 1.231-4.597; p = 0.01).

CONCLUSIONS

CAP measurements have predictive value in patients with virologically quiescent CHB. The presence of hepatic steatosis was associated with a higher risk of fibrosis progression but, paradoxically, a 3-fold increase in HBsAg seroclearance rate.

LAY SUMMARY

Co-existing fatty liver disease in patients with chronic viral hepatitis B infection leads to worsening liver fibrosis, but also increases the chance of cure from hepatitis B virus. Routine bedside assessment of liver fat content is important for risk assessment in treatment-naïve patients with chronic hepatitis B.

Use of HBsAg quantification in the natural history and treatment of chronic hepatitis B

In patients with chronic hepatitis B (CHB) infection, it is important to monitor the natural history, assess treatment response, and predict the risk of liver-related complications. Quantification of serum hepatitis B surface antigen (HBsAg) has gained wide interests since the last decade. It is secreted from hepatocytes in both hepatitis B e antigen (HBeAg)-positive and HBeAg-negative phases of the disease, and can be transcribed and translated from different sources of viral genome [ccc DNA or integrated hepatitis B virus (HBV) DNA]. In untreated patients, it declines slowly through the natural course and remains stable for a long time after HBeAg seroconversion. In patients treated with nucleos(t)ide analogues (NA), it also declines very slowly, even though serum hepatitis B DNA has been rendered negative. Low serum HBsAg may predict either spontaneous or treatment-induced HBsAg seroclearance, and potentially selects out HBeAg-negative patients who can safely stop NA. High serum HBsAg is associated with high risk of hepatocellular carcinoma in untreated population, and predicts treatment failure in patients receiving pegylated interferon. These potential roles of HBsAg quantification are applicable to selected populations only. There is also a need for novel markers to study the effect of emerging antiviral therapies targeting various parts of the HBV cycle to reflect their distinct mechanistic effects. Several agents measuring HBsAg levels have shown rapid and significant decline. Ongoing studies are required to demonstrate the sustainability of HBsAg suppression by these novel agents.

Systematic review: cessation of long-term nucleos(t)ide analogue therapy in patients with hepatitis B e antigen-negative chronic hepatitis B

BACKGROUND

It has been debated whether finite nucleos(t)ide analogue therapy is feasible in HBeAg-negative chronic hepatitis B.

AIM

To review this issue systematically.

METHODS

Using text terms HBsAg and various nucleos(t)ide analogues, PubMed was searched between 1995 and 2014 to find studies on therapy >6 months in adult HBeAg-negative chronic hepatitis B patients with off-therapy follow-up >6 months.

RESULTS

Twenty-two studies with a total of 1732 patients were identified and included. The median duration of therapy, consolidation therapy and off-therapy follow-up ranged from 6 months to 8 years, 4 to 96 weeks and 6 to 80 months respectively. Patients were monitored with serum ALT and HBV DNA monthly in the first 1-3 months and every 3-6 months afterwards in most studies. The 1-year off-therapy 'virological relapse' (HBV DNA >2000 IU/mL) and 'clinical relapse' (HBV DNA > 2000 IU/mL + ALT elevation) occurred in <70% and <50% of the patients, respectively, and <40% of the patients received re-treatment. These rates were higher in patients with shorter treatment, shorter consolidation therapy and those treated with less potent nucleos(t)ide analogues. Off-therapy severe flares were rare and hepatic decompensation was reported in only one patient with cirrhosis. Biochemical relapse reflecting enhanced immune-mediated hepatocyte killing may lead to a higher chance for off-therapy HBsAg seroclearance and be possibly desirable.

CONCLUSION

With an appropriate stopping rule and a proper off-therapy monitoring plan, cessation of long-term nucleos(t)ide analogue therapy prior to HBsAg seroclearance in HBeAg-negative chronic hepatitis B is a feasible alternative to indefinite treatment.

The correlation between serum HBsAg levels and viral loads depends upon wild-type and mutated HBV sequences rather than the HBeAg/anti-HBe status

Despite several studies regarding the correlation between serum HBsAg titers and viral loads, the association remains uncertain. Eighty‐nine individuals were selected randomly from a Chinese cohort of 2,258 subjects infected persistently with hepatitis B virus (HBV) for cross‐sectional and longitudinal analysis. Viral loads of mutant HBV are lower than those of wild type HBV. The serum HBsAg titers correlate positively with viral loads in both HBeAg positive and negative subjects (r = 0.449, P = 0.013; r = 0.300, P = 0.018, respectively). No correlation between serum HBsAg titer and viral loads was found in any of the four phases of chronic HBV infection. The serum HBsAg titers correlate positively with viral loads in the group with wild type sequences of the PreS/S, basal core promoter (BCP), and preC regions of HBV(r = 0.502, P = 0.040). However, the correlation was not seen in the group with mutations in these regions (r = 0.165, P = 0.257). The correlation between HBsAg titers and viral loads was seen in individuals with wild type PreS/S sequences but not in the subgroup with BCP double mutations or PreC stop mutation, although their sequences in the preS/S regions were wild type. All these findings were confirmed by the longitudinal analysis. In conclusion, the correlation between serum HBsAg levels and viral loads may not differ between HBeAg positive and negative individuals but may depend on wild‐type or mutated genomic sequences. Therefore, HBsAg quantitation may be used as a surrogate for viral loads in only wild‐type HBV infections. J. Med. Virol. 87:1351–1360, 2015. © 2015 The Authors. Journal of Medical Virology Published by Wiley Periodicals, Inc.

Hepatitis B surface antigen levels after hepatitis B e-antigen seroclearance: a longitudinal follow-up study

BACKGROUND & AIMS

The role of quantitative hepatitis B surface antigen (HBsAg) after hepatitis B e-antigen (HBeAg) seroclearance is not well defined. To determine the role of HBsAg levels in predicting significant viremia and hepatitis flares after HBeAg seroclearance.

METHODS

A total of 228 chronic hepatitis B patients with spontaneous HBeAg seroclearance were included. Patients were followed up regularly at 3-6 monthly intervals with routine liver biochemistry and hepatitis B serology. Levels of HBV DNA and HBsAg were measured at yearly intervals for up to 5 years after HBeAg seroclearance.

RESULTS

The median log HBsAg and HBV DNA level after HBeAg seroclearance was 3.52 IU/ml and 4.13 IU/ ml respectively, with no significant correlation observed between them (P = 0.572). The HBV DNA at HBeAg seroclearance was 4.13 log IU/ml, compared with 3.12 log IU/ml after 5 years (P < 0.001). No significant change was observed for HBsAg levels (P = 0.991). Hepatitis B flares occurred in 76 (33.3%) patients. Patients who developed hepatitic flares compared with those without hepatitic flares were older (40 vs. 36 years, P = 0.001), had a higher HBV DNA at the time of HBeAg seroclearance (4.70 vs. 3.77 log IU/ml, P =< 0.001), and more likely to be males (42.7% vs. 23.4%, P = 0.002) respectively. There was no difference in HBsAg levels between those with and without hepatitis flare (3.54 vs. 3.52 log IU/ml respectively, P = 0.555).

CONCLUSION

HBV DNA levels, but not HBsAg levels, after HBeAg seroclearance were associated with subsequent significant viremia and hepatitic flares. Male gender and older age was associated with significant viremia.

Patterns of hepatitis B surface antigen decline and HBV DNA suppression in Asian treatment-experienced chronic hepatitis B patients after three years of tenofovir treatment

BACKGROUND & AIMS

Patterns of serum hepatitis B surface antigen (HBsAg) decline during nucleos(t)ide analogue (NA) therapy have not been well investigated.

METHODS

We determined the cumulative serologic, virologic, and biochemical outcomes of 142 Asian CHB patients, with at least 6 months exposure to other NAs, receiving tenofovir with or without lamivudine for up to 3 years. Liver biochemistry, serum HBV DNA, and HBsAg levels were determined at baseline, 6 months and yearly from years 1 to 3.

RESULTS

142, 123 (86.6%), and 70 (49.3%) CHB patients were followed up for 1, 2, and 3 years, respectively. Two phases of HBsAg decline were observed. Patients with baseline HBsAg ≥3 log IU/ml, when compared to patients with baseline HBsAg < 3 log IU/ml, had a greater median rate of HBsAg reduction through 3 years of treatment (0.155 and 0.039 log IU/ml/year respectively, p < 0.001). Among patients with 3 years of follow-up, there was a significantly greater median rate of HBsAg reduction during the first year when compared to the second and third years (0.220, 0.136, and 0.081 log IU/ml/year respectively, p < 0.001). HBeAg status, HBV genotype, and concomitant lamivudine therapy were not important determinants of HBsAg kinetics (all p > 0.05). The 3-year cumulative virologic suppression rate was 93.3%, with no cases of resistance detected.

CONCLUSIONS

Serum HBsAg levels in NA-experienced patients receiving tenofovir demonstrated a variable pattern of decline, with slower rates of reduction noted in patients with lower baseline HBsAg levels, and could explain the rarity of HBsAg seroclearance during NA therapy.

Reduction of hepatitis B surface antigen levels and hepatitis B surface antigen seroclearance in chronic hepatitis B patients receiving 10 years of nucleoside analogue therapy

The profile and clinical significance of serum hepatitis B surface antigen (HBsAg) levels during long-term nucleoside analogue (NA) therapy in chronic hepatitis B (CHB) is undetermined. From 1994 to 2002, 322 Chinese CHB patients were started on lamivudine in our center. Patients were recruited if they were continuously treated with lamivudine for at least 10 years and maintained favorable virologic responses throughout therapy (HBV DNA <2,000 IU/mL). HBsAg and HBV DNA levels were measured serially, and the predictability of HBsAg kinetics in determining NA-related HBsAg seroclearance was determined. Seventy patients were recruited, of which 43 (61.4%) were hepatitis B e antigen (HBeAg)-positive. Fifty-two (74.3%) patients had undetectable viremia (HBV DNA <20 IU/mL) during therapy. Fifteen (21.4%) patients were followed up for 15 years. The median rate of HBsAg reduction was 0.104 log IU/mL/year, with no significant difference found when comparing patients who were HBeAg-positive versus HBeAg-negative, were genotype B versus C, and had detectable versus undetectable viremia during therapy (all P > 0.05). Seven (10%) patients achieved HBsAg seroclearance, and when compared with the remaining 63 patients, had significantly lower median baseline HBsAg levels (P = 0.012) and a greater median rate of HBsAg reduction (P < 0.001). Baseline HBsAg levels and the rate of HBsAg reduction achieved an area under the receiver operating characteristic curve of 0.860 (P = 0.004; 95% confidence interval [CI], 0.742-0.978) and 0.794 (P = 0.018; 95% CI, 0.608-0.979), respectively. Baseline HBsAg <1,000 IU/mL and on-treatment reduction of HBsAg >0.166 log IU/mL/year were optimal cutoff levels in predicting subsequent HBsAg seroclearance (negative predictive values, 98.1% and 97.8%, respectively).

CONCLUSION

Low baseline HBsAg levels and greater rate of HBsAg reduction achieved high predictive values for predicting HBsAg seroclearance, strengthening the prognostic role of HBsAg measurements during NA therapy.

Clinical utility of quantitative HBsAg in natural history and nucleos(t)ide analogue treatment of chronic hepatitis B: new trick of old dog

Using commercial quantitative assays, quantitative hepatitis B surface antigen (qHBsAg) has improved our understanding and management of chronic hepatitis B (CHB). The HBsAg level is highest in the immune tolerance phase, starts to decline during the immune clearance phase, and decreases slowly but progressively after hepatitis B e antigen (HBeAg) seroconversion. The HBsAg level is lowest in individuals with an inactive carrier state but higher in those who develop HBeAg-negative hepatitis. It has been shown that a reduction of HBsAg by 1 log IU/mL or more reflects improved host immune control of HBV infection. A combination of HBsAg <1000 IU/mL and HBV-DNA <2000 IU/mL can identify a 3-year inactive state in a genotype D HBeAg-negative carrier population. In the Asian-Pacific region, where HBV genotypes B and C are dominant, HBsAg levels of ≤10-100 IU/mL predict HBsAg loss over time. As to the prediction of disease progression, low-viremic carriers with HBsAg >1000 IU/mL have been shown to be at higher risks of HBeAg-negative hepatitis, cirrhosis, and hepatocellular carcinoma than those with HBsAg <1000 IU/mL. Although qHBsAg has been widely used in CHB patients receiving pegylated interferon therapy, the HBsAg decline is slow and does not correlate with HBV-DNA levels during nucleos(t)ide analogue (NUC) therapy. However, a rapid HBsAg decline during NUC therapy may identify patients who will finally clear HBsAg. A 6- to 12-monthly assessment of HBsAg level could be considered during NUC therapy. Taking these lines of evidence together, qHBsAg can complement HBV-DNA levels to optimize the management of CHB patients in our daily clinical practice.