The distribution of HBV genotypes and clinical significance in familial clustering in an infected population with unfavorable prognosis

Efficacy and safety of telbivudine and tenofovir disoproxil fumarate in preventing hepatitis B vertical transmission: A real-life practice

Mother-to-child transmission (MTCT) is a major obstacle in the elimination of hepatitis B virus (HBV) infection. Telbivudine (LdT) and tenofovir disoproxil fumarate (TDF) are the two most common antiviral medicines for preventing MTCT. However, the efficacy and safety of LdT and TDF in preventing HBV vertical transmission during the second to third trimester have not been compared rigorously. Therefore, we carried out a prospective multicentre cohort study of chronic hepatitis B in mothers with HBV DNA > 10⁶  IU/mL, receiving LdT or TDF during the second to third trimester. Among the 893 mothers enrolled, 857 (LdT/TDF/untreated group (NTx) = 396/325/136) completed consecutive follow-up with 854 infants (LdT/TDF/NTx = 395/323/136). LdT and TDF treatment resulted in a similar decrease of HBV DNA in mothers at delivery. Multivariate analysis indicated that only HBsAg titre at the baseline correlated with viral DNA decrease (P = 0.015). With intention-to-treat analysis, MTCT rates in the LdT, TDF and NTx group were 4.41%, 2.42% and 22.08%, respectively. An increasing vertical transmission rate was found to be closely associated with higher HBsAg titre, 5.32% and 17.65% infection rate was estimated in infants born to mothers with HBsAg > 4 and >5 log₁₀ IU/mL, respectively. No serious side effects were reported in either mothers or infants. LdT and TDF treatments were well tolerated and showed comparable efficacy in reducing MTCT. Higher risk of MTCT was shown in pregnant women with HBsAg > 4 log₁₀ IU/mL.

A molecular epidemiology study investigating familial clustering of hepatitis B virus infection in families with unfavorable prognoses in Northwest China

Hepatitis B virus (HBV) infections and adverse outcome have been demonstrated to show characteristics of familial clustering. The aim of this study was to investigate the prevalence of different HBV genotypes, HBV sub-genotypes, and Pre-S mutations associated with familial HBV infection clusters with unfavorable prognoses. Families presenting with clustered HBV infections and unfavorable prognoses were enrolled in this study. Non-clustered HBV-infected individuals were used as the control group. DNA extracted from patient serum samples was used to facilitate characterization of the HBV genotypes, HBV sub-genotypes, and Pre-S mutations by phylogenetic analysis. The Pre-S/S gene was successfully amplified in 83 patients from the clustering group and 105 patients from the sporadic group. The prevalence of genotype C in the clustering group (71/83, 85.54%) was significantly higher than in the sporadic group (77/105, 73.33%) (P = 0.042). The prevalence of sub-genotype C2 in the clustering group (33/83, 39.76%) was also higher than in the sporadic group (21/105, 20%) (P = 0.003). Analyses of functional mapping of pre-S sequences showed that the prevalence of the mutation in the S promoter site (nt 3045-3189 of pre-S1 domain) was significantly increased in the clustering group compared with the sporadic group (15.7% vs. 3.8%) (P = 0.009). This study suggests that genotype C, especially sub-genotype C2, may be associated with the progression of HBV infection in familial clustering infection cohorts with unfavorable prognoses. We also observed that the natural occurrence of S promoter mutations in the clustering group was significantly prevalent.

A SNaPshot assay for the rapid and simple detection of hepatitis B virus genotypes

A simple technique for the identification of common genotypes of the hepatitis B virus (HBV) remains to be identified. The present study was conducted to establish such a methodology. Four plasmids of genotypes A-D and 123 clinical serum specimens of HBV-infected patients were genotyped. HBV genotypes would be detected successfully when the HBV genotype reached a viral load of 1 × 10³ copies/ml or the BC genotype mixed samples reached a 5% level. The lower limit of detection of HBV DNA in serum specimens was determined to be 2.14×10² IU/ml. The assay sensitivity and specificity were 100% and the consistency was demonstrated to reach as high as 90.24 and 100% compared with that of the DNA sequencing and cloning. The frequencies of the genotypes B, C, BC, BD and BCD were found to be 65.0, 23.6, 7.3, 3.3 and 0.8%, respectively. The accuracy of detection of the mixed infections was also higher using the rapid and simple SNaPshot method compared with that achieved with the DNA sequencing methods. The results of the present study indicated that the SNaPshot technique accurately distinguishes the HBV genotypes A-D and is able to be readily applied as a monitoring tool in HBV prognosis and treatment.

Dynamic changes of HBV markers and HBV DNA load in infants born to HBsAg(+) mothers: can positivity of HBsAg or HBV DNA at birth be an indicator for HBV infection of infants?

Background

Neither HBV DNA nor HBsAg positivity at birth is an accurate marker for HBV infection of infants. No data is available for continuous changes of HBV markers in newborns to HBsAg(+) mothers. This prospective, multi-centers study aims at observing the dynamic changes of HBV markers and exploring an early diagnostic marker for mother-infant infection.

Methods

One hundred forty-eight HBsAg(+) mothers and their newborns were enrolled after mothers signed the informed consent forms. Those infants were received combination immunoprophylaxis (hepatitis B immunoglobulin [HBIG] and hepatitis B vaccine) at birth, and then followed up to 12 months. Venous blood of the infants (0, 1, 7, and 12 months of age) was collected to test for HBV DNA and HBV markers.

Results

Of the 148 infants enrolled in our study, 41 and 24 infants were detected as HBsAg(+) and HBV DNA(+) at birth, respectively. Nine were diagnosed with HBV infection after 7 mo follow-up. Dynamic observation of the HBV markers showed that HBV DNA and HBsAg decreased gradually and eventually sero-converted to negativity in the non-infected infants, whereas in the infected infants, HBV DNA and HBsAg were persistently positive, or higher at the end of follow-up. At 1 mo, the infants with anti-HBs(+), despite positivity for HBsAg or HBV DNA at birth, were resolved after 12 mo follow-up, whereas all the nine infants with anti-HBs(−) were diagnosed with HBV infection. Anti-HBs(−) at 1 mo showed a higher positive likelihood ratio for HBV mother-infant infection than HBV DNA and/or HBsAg at birth.

Conclusions

Negativity for anti-HBs at 1 mo can be considered as a sensitive and early diagnostic indictor for HBV infection in the infants with positive HBV DNA and HBsAg at birth, especially for those infants with low levels of HBV DNA load and HBsAg titer.

Age versus clinical virological characteristics in chronic hepatitis B virus infection: a case series study in China

OBJECTIVES

This study aimed to investigate the clinical virological characteristics of hepatitis B virus (HBV) in chronic HBV infection patients of different ages, especially in relapse patients and patients with immune clearance.

METHODS

The HBV clinical virological characteristics of chronic HBV infection were investigated in 1572 Chinese patients of different age groups (<20, 20-40, and >40 years old).

RESULTS

Of the patients in the below 20 age group, those with evidence of immune tolerance accounted for 86.05% (P<0.001). Of the patients in the 20-40 age group, those with immune clearance accounted for 36.36% (P<0.001). Of the patients in the above 40 age group, there were markedly more reactivation cases than in any other group (P<0.001). Our data indicated that a positive correlation (r=0.480, P<0.001) existed between HBV DNA contents (on a log10 scale) and the alanine aminotransferase (ALT) level of the total cases with reactivation. Of the 300 cases with immune clearance being followed up 10-50 months after enrollment, 181 cases achieved spontaneous hepatitis B e antigen (HBeAg) seroconversion (HBeAg to anti-HBe), and the younger the patient, the shorter the time to seroconversion (P<0.05).

CONCLUSION

Generally, there were significantly different HBV clinical virological characteristics in patients with chronic HBV infection of different ages. Different features were observed in relapse patients and patients with immune clearance at different ages, and these two types of patients needed antiretroviral therapy. Our study suggests that revisions of the timing and elevated alanine aminotransferase standards for chronic hepatitis B antiretroviral therapy in Chinese relapse patients and patients with immune clearance in different age groups are warranted.