Predicting hepatitis B e Antigen seroconversion after pregnancy-The SydPregScore.

BACKGROUND AND AIMS: Achieving Hepatitis B e antigen seroconversion (HBeAg SC) at an earlier age confers a better prognosis. We examined baseline and post-partum factors associated with HBeAg SC after pregnancy. We developed a tool, the SydPregScore, to estimate the likelihood of HBeAg SC in the years after pregnancy. METHODS: A retrospective analysis of an HBeAg-positive pregnant cohort was conducted. Variables including baseline age, parity, alanine aminotransferase level, HBV viral load, quantitative HBsAg, use of antiviral therapy and post-partum flare were collected. Univariate and multivariate Cox regression analyses to determine predictors of HBeAg SC and develop a predictor score were performed. RESULTS: We analysed HBeAg SC rates in 220 pregnancies to 149 HBeAg-positive women from 2006 to 2019. At baseline, their median age was 33 (IQR 29-37), ALT 23 U/L (IQR 17-33) and viral load 8 log10 IU/mL (IQR 6.3-8.2 log10 IU/mL). The majority (133/198, 67.2%) received short-course antiviral therapy to prevent mother-to-child transmission, and 109/192 (56.8%) had a post-partum flare. HBeAg SC occurred in 74/220 (33.6%) after pregnancy (median follow-up 814 days, IQR 405-1531). Multivariate analysis identified baseline viral load <8 log10 IU/mL (HR 2.426 [1.224-4.809], p = .011), baseline ALT ≥2 ULN (HR 2.726 [1.299-5.721], p = .008) and age <35 (HR 2.859 [1.255-6.513], p = .012) to be positive predictors of HBeAg SC. The 'SydPreg Score' estimated the probability of HBeAg SC at 2000 days as 10%, 30%, 70% and 80% for 0, 1, 2, and 3 predictors respectively. CONCLUSION: The SydPreg Score allows the prediction of HBeAg SC in the years after pregnancy. Even in those without elevated ALT, age <35 and viral load <8 log10 IU/mL can identify women with a good chance of subsequent HBeAg SC. Those without a chance may benefit from viral suppression.

Mother-to-child transmission of hepatitis B: Examining viral cut-offs, maternal HBsAg serology and infant testing.

BACKGROUND & AIMS: Antipartum antiviral therapy in the setting of high viral load is recommended to prevent mother-to-child transmission of hepatitis B although recommended viral load cut-offs vary. Quantitative HBsAg has been proposed as an alternative screening strategy to identify high viral load in this setting. Guidelines suggest testing all infants for vaccine response and infection. We set out to re-examine viral load cut-offs; the predictive value of quantitative HBsAg and the need for follow-up infant testing in our cohort. METHODS: A retrospective cohort study of 469 HBsAg positive mother-baby pairs from 2 tertiary hospitals in Sydney was performed. Antiviral therapy (lamivudine or tenofovir disoproxil fumarate) was offered to women with viral load ≥6 log10  IU/mL (high) from 32 weeks gestation. Transmission and vaccine response was analysed according to viral load. The utility of quantitative HBsAg in identifying high viral load was examined. RESULTS: Mother-to-child transmission only occurred in setting of high viral load, in 0.85% (1/117) of those who received antiviral therapy and in 8.66% (2/23) of those who chose not to. Quantitative HBsAg did not accurately identify high-risk mothers HBV DNA ≥6 log10  IU/mL. Successful infant vaccine response was 98.7% overall, and 99.4% when viral load was <6 log10  IU/mL. CONCLUSION: Antiviral therapy initiated at 32 weeks when maternal viral load is ≥6 log10  IU/mL almost completely abrogates transmission. Quantitative HBsAg does not reliably predict high viral load. When maternal viral load is <6 log10  IU/mL, high vaccine efficacy and zero transmission suggests testing infants is of little value.

Ty1 mobilizes subtelomeric Y' elements in telomerase-negative Saccharomyces cerevisiae survivors.

When telomerase is inactivated in Saccharomyces cerevisiae, telomeric DNA shortens with every cell division, and cells stop dividing after approximately 100 generations. Survivors that form in these senescent populations and resume growing have variably amplified arrays of subtelomeric Y' elements. We marked a chromosomal Y' element with the his3AI retrotransposition indicator gene and found that Y'HIS3 cDNA was incorporated into the genome at approximately 10- to 1,000-fold-higher frequencies in survivors compared to telomerase-positive strains. Y'HIS3 cDNA mobility was significantly reduced if assayed at 30 degrees C, a nonpermissive temperature for Ty1 retrotransposition, or in the absence of Tec1p, a transcription factor for Ty1. Microarray analysis revealed that Y' RNA is preferentially associated with Ty1 virus-like particles (VLPs). Genomic copies of Y'HIS3 cDNA typically have downstream oligo(A) tracts, followed by a complete Ty1 long terminal repeat and TYA1 or TYB1 sequences. These data are consistent with the use of Ty1 cDNA to prime reverse transcription of polyadenylated Y' RNA within Ty1 VLPs. Unmarked Y'-oligo(A)-Ty1 cDNA was also detected in survivors, reaching copy numbers of approximately 10(-2) per genome. We propose that Y'-oligo(A)-Ty1 cDNA recombines with Y' elements at eroding telomeres in survivors and may play a role in telomere maintenance in the absence of telomerase.

Hepatitis C Virus Treatment in HIV-Coinfected Patients: No Longer Different From Monoinfection Treatment.

Between 15% and 30% of patients infected with HIV in the United States and Europe are coinfected with hepatitis C virus (HCV), and rates of acute HCV infection have been increasing in some populations of HIV-positive patients. Liver disease is now a leading cause of death in HIV-infected patients. Patients with HIV/HCV coinfection have lower rates of spontaneous acute HCV clearance, poorer response to treatment of chronic HCV in the pre-direct-acting antiviral era, more rapid progression to cirrhosis, and increased risk of hepatocellular carcinoma. This article will summarize data on management of HIV/HCV coinfection, discuss the epidemic of acute HCV infection in HIV-infected patients, and examine the many new HCV treatment regimens on the horizon with data on coinfected patients.

A nucleocapsid functionality contained within the amino terminus of the Ty1 protease that is distinct and separable from proteolytic activity.

Ty1 is the most successful of the five endogenous yeast retrotransposons. The life cycle of Ty1 dictates that a number of nucleocapsid (NC)-facilitated events occur although the protein(s) responsible for these events has not been identified. The positioning of the NC peptide is conserved at the carboxy terminus of the Gag protein among most long terminal repeat (LTR)-containing retroelements. An analogous region of Ty1 that simultaneously encodes part of Gag, protease (PR), and the C-terminal p4 peptide was mutagenized. Some of these mutations result in smaller-than-normal virus-like particles (VLPs). The mutants were also found to impair an NC-like functionality contained within the amino terminus of the protease that is distinct and separable from its proteolytic activity. Remarkably, these mutants have distinct defects in reverse transcription.

Ty1 defect in proteolysis at high temperature.

Retrotransposition of the Ty1 element of Saccharomyces cerevisiae is temperature sensitive. Transposition activity of Ty1 is abolished at temperatures above 34 degrees C. In this report, we show that the major block to transposition at high temperature is the inhibition of processing of the Gag-Pol-p199 polyprotein and the concomitant reduction of reverse transcriptase (RT) activity. Expression of a Ty1 protease construct in Escherichia coli shows that protease enzymatic activity is inherently temperature sensitive. In yeast, Gag processing is only partially inhibited at high temperature, while cleavage of the Gag-Pol polyprotein is completely inhibited. Sites of proteolytic processing are differentially susceptible to cleavage during growth at high temperature. Overall levels of the Gag-Pol polyprotein are reduced at high temperature, although the efficiency of the requisite +1 frameshifting event appears to be increased. RT activity is inherently relatively temperature resistant, yet no cDNA is made at high temperature and the amount of RT activity is greatly reduced in virus-like particles formed at high temperature. Taken together, these results suggest that alterations in Ty1 proteins that occur at high temperature affect both protease activity and RT activity, such that Ty1 transposition is abolished.