A sensitive and rapid assay for investigating vertical transmission of hepatitis B virus via male germ line using EGFP Vector as reporter

Swim-up as a strategy for isolation of spermatozoa without viral incorporation in men with chronic hepatitis B: A pilot study

Hepatitis B virus (HBV) incorporates into spermatozoa which raises safety concerns about paternofetal transmission performing intracytoplasmatic sperm injection (ICSI) in men with chronic hepatitis B (cHB). HBV reduces sperm cell motility, assuming spermatozoa with highest motility are least HBV-incorporated. This study investigates an ICSI preparation technique (swim-up) to isolate most motile spermatozoa in order to select HBV-free spermatozoa. Semen and blood samples were collected from four patients with cHB. Spermatozoa were incubated in trajectories of gamete medium to create non-motile, motile/non-progressive and motile/progressive fractions. After DNA-extraction, HBV DNA loads were determined in every fraction. Participants (mean age 31) were HBsAg+(4/4), anti-HBc+(4/4) and HBV DNA+(2/4). They were treated (3/4) with entecavir(1/4) or tenofovir (2/4) and had no adverse sperm parameters(3/4). CRP-gene was detected in 95/96 sample fractions, proving successful DNA-extraction. HBV DNA was detected in none of the sample fractions, except for the motile, non-progressive fraction of one patient (HBeAg+, HBV DNA+). Since no HBV DNA was detected in progressive fractions, this study suggests swim-up a successful strategy to select HBV-free spermatozoa. Since all but one fraction was HBV DNA-negative, this study also suggests that patients with well-controlled disease have no HBV-contaminated sample fractions. This study encourages evaluation of guidelines restricting reproductive possibilities in men with cHB.

Risk of vertical transmission of hepatitis B after amniocentesis in HBs antigen-positive mothers

BACKGROUND & AIMS

Despite appropriate immunoprophylaxis, HBV vertical transmission (VT) occurs in 5-10% of infants born to HBs-antigen (HBsAg)+ mothers. We investigated whether amniocentesis increases the risk of transmission.

METHODS

We performed a case-control study on infants who were born to HBsAg+ mothers without antiviral exposure and completed appropriate immunization. Infants born to mothers with amniocentesis were compared to those without amniocentesis to assess VT rates, which were defined by the percentage of infants with HBsAg positivity when they were 7-12 months old.

RESULTS

Of the 642 consecutive infants enrolled, 63 infants with amniocentesis were compared with 198 matched infants selected from the remaining 579 infants without amniocentesis. There was a higher VT rate in infants with amniocentesis than in those without amniocentesis (6.35% vs. 2.53%; p=0.226). Maternal HBV DNA levels before amniocentesis were further stratified to <500 copies/ml, 500-6.99 log10 copies/ml, and ⩾ 7 log10 copies/ml for subset analyses. There were no significant differences in the VT rates between the amniocentesis group and the control group if the maternal HBV DNA levels were <6.99 log10 copies/ml. However, a significantly higher VT rate was observed in the amniocentesis group vs. the control group if the maternal HBV DNA levels were ⩾ 7 log10 copies/ml (50% vs. 4.5%, respectively, p=0.006). According to baseline value risk analyses, performing amniocentesis on highly viremic mothers was a risk factor for HBV transmission (OR=21.3, 95% CI: 2.960-153.775).

CONCLUSIONS

Amniocentesis performed on HBsAg+ mothers with HBV DNA ⩾ 7 log10 copies/ml significantly increased the frequency of VT. HBsAg+ women who plan to have amniocentesis should be evaluated for the risk of VT and stratified according to their HBV DNA levels. Further prospective studies are warranted to verify our findings.

A pregnant patient with a positive hepatitis B surface antigen

Hepatitis B is a major cause of liver disease worldwide. The highest rates of chronic infection occur in subjects who are infected early in life and these patients are also at the greatest risk of developing complications such as hepatocellular carcinoma and cirrhosis from the disease. There has been a concerted worldwide effort to immunise newborns that are at the highest risk of acquiring infection. In 1992, when WHO recommended global vaccination against hepatitis B, only 31 countries elected to participate in the programme. By 2009, 177 countries were part of WHO national infant immunisation programme. Consequently, maternal screening and infant immunoprophylaxis have significantly reduced vertical transmission of hepatitis B. In this paper, we will review the management of hepatitis B in the pregnant population and identify some of the challenges that are encountered in this specialised population.

An algorithm for risk assessment and intervention of mother to child transmission of hepatitis B virus

BACKGROUND & AIMS

Despite immunoprophylaxis, mother to child transmission (MTCT) of hepatitis B virus (HBV) still occurs in infants born to hepatitis B surface antigen (HBsAg)-positive mothers. We analyzed methods of risk assessment and interventions for MTCT.

METHODS

We reviewed 63 articles and abstracts published from 1975-2011 that were relevant to MTCT; articles were identified using the PubMed bibliographic database.

RESULTS

Administration of HB immunoglobulin and HB vaccine to infants at birth (within 12 hours), followed by 2 additional doses of vaccines within 6-12 months, prevented approximately 95% of HBV transmission from HBsAg-positive mothers to their infants. However, HBV was still transmitted from 8%-30% of mothers with high levels of viremia. It is important to assess the risk for MTCT and identify mothers who are the best candidates for intervention. The most important risk factor is maternal level of HBV DNA >200,000 IU (10(6) copies)/mL; other factors include a positive test result for the HB e antigen, pregnancy complications such as threatened preterm labor or prolonged labor, and failure of immunoprophylaxis in prior children. Antiviral therapy during late stages of pregnancy is the most effective method to reduce transmission from mothers with high levels of viremia, but elective cesarean section might also be effective. Antepartum administration of HB immunoglobulin, giving infants a double dose of HB vaccine, or avoiding breastfeeding had no impact on MTCT.

CONCLUSIONS

HBsAg-positive mothers should be assessed for risk of MTCT, and infants should receive immunoprophylaxis. Pregnant women with levels of HBV DNA >200,000 IU/mL should be considered for strategies to reduce the risk for MTCT. We propose an algorithm for risk assessment and patient management that is based on a review of the literature and the opinion of a panel of physicians with expertise in preventing MTCT.

Development of NS3/4A protease-based reporter assay suitable for efficiently assessing hepatitis C virus infection

A cell culture system for the production of hepatitis C virus (HCV) whole virions has greatly accelerated studies of the virus life cycle and the discovery of anti-HCV agents. However, the quantification of the HCV titers in a whole-virus infection/replication system currently relies mostly on reverse transcription-PCR or immunofluorescence assay, which would be cumbersome for high-throughput drug screening. To overcome this problem, this study has generated a novel cell line, Huh7.5-EG(Delta4B5A)SEAP, that carries a dual reporter, EG(Delta4B5A)SEAP. The EG(Delta4B5A)SEAP reporter is a viral protease-cleavable fusion protein in which the enhanced green fluorescence protein is linked to secreted alkaline phosphatase (SEAP) in frame via Delta4B5A, a short peptide cleavage substrate for NS3/4A viral protease. This study demonstrates that virus replication/infection in the Huh7.5-EG(Delta4B5A)SEAP cells can be quantitatively indicated by measuring the SEAP activity in cell culture medium. The levels of SEAP released from HCV-infected Huh7.5-EG(Delta4B5A)SEAP cells correlated closely with the amounts of HCV in the inocula. The Huh7.5-EG(Delta4B5A)SEAP cells were also shown to be a suitable host for the discovery of anti-HCV inhibitors by using known compounds that target multiple stages of the HCV life cycle. The Z'-factor of this assay ranged from 0.64 to 0.74 in 96-well plates, indicating that this reporter system is suitable for high-throughput screening of prospective anti-HCV agents.