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BackgroundRemdesivir, a nucleotide analogue prodrug that inhibits viral RNA polymerases, has shown in vitro activity against SARS-CoV-2.MethodsWe provided remdesivir on a compassionate-use basis to patients hospitalized with Covid-19, the illness caused by infection with SARS-CoV-2. Patients were those with confirmed SARS-CoV-2 infection who had an oxygen saturation of 94% or less while they were breathing ambient air or who were receiving oxygen support. Patients received a 10-day course of remdesivir, consisting of 200 mg administered intravenously on day 1, followed by 100 mg daily for the remaining 9 days of treatment. This report is based on data from patients who received remdesivir during the period from January 25, 2020, through March 7, 2020, and have clinical data for at least 1 subsequent day.ResultsOf the 61 patients who received at least one dose of remdesivir, data from 8 could not be analyzed (including 7 patients with no post-treatment data and 1 with a dosing error). Of the 53 patients whose data were analyzed, 22 were in the United States, 22 in Europe or Canada, and 9 in Japan. At baseline, 30 patients (57%) were receiving mechanical ventilation and 4 (8%) were receiving extracorporeal membrane oxygenation. During a median follow-up of 18 days, 36 patients (68%) had an improvement in oxygen-support class, including 17 of 30 patients (57%) receiving mechanical ventilation who were extubated. A total of 25 patients (47%) were discharged, and 7 patients (13%) died; mortality was 18% (6 of 34) among patients receiving invasive ventilation and 5% (1 of 19) among those not receiving invasive ventilation.ConclusionsIn this cohort of patients hospitalized for severe Covid-19 who were treated with compassionate-use remdesivir, clinical improvement was observed in 36 of 53 patients (68%). Measurement of efficacy will require ongoing randomized, placebo-controlled trials of remdesivir therapy. (Funded by Gilead Sciences.).

Depending on age of acquisition, hepatitis B virus (HBV) can induce a cell-mediated immune response that results in either cure or progressive liver injury. In adult-acquired infection, HBV antigens are usually cleared, whereas in infancy-acquired infection, they persist. Individuals infected during infancy therefore represent the majority of patients chronically infected with HBV (CHB). A therapy that can promote viral antigen clearance in most CHB patients has not been developed and would represent a major health care advance and cost mitigator. Using an age-dependent mouse model of HBV clearance and persistence in conjunction with human blood and liver tissue, we studied mechanisms of viral clearance to identify new therapeutic targets. We demonstrate that age-dependent expression of the costimulatory molecule OX40 ligand (OX40L) by hepatic innate immune cells is pivotal in determining HBV immunity, and that treatment with OX40 agonists leads to improved HBV antigen clearance in young mice, as well as increased strength of T cell responses in young mice and adult mice that were exposed to HBV when they were young and developed a CHB serological profile. Similarly, in humans, we show that hepatic OX40L transcript expression is age-dependent and that increased OX40 expression on peripheral CD4+ T cells in adults is associated with HBV clearance. These findings provide new mechanistic understanding of the immune pathways and cells necessary for HBV immunity and identify potential therapeutic targets for resolving CHB.

Accumulation of activated immune cells results in nonspecific hepatocyte killing in chronic hepatitis B (CHB), leading to fibrosis and cirrhosis. This study aims to understand the underlying mechanisms in humans and to define whether these are driven by widespread activation or a subpopulation of immune cells. We enrolled CHB patients with active liver damage to receive antiviral therapy and performed longitudinal liver sampling using fine-needle aspiration to investigate mechanisms of CHB pathogenesis in the human liver. Single-cell sequencing of total liver cells revealed a distinct liver-resident, polyclonal [CD8.sup.+] T cell population that was enriched at baseline and displayed a highly activated immune signature during liver damage. Cytokine combinations, identified by in silico prediction of ligand-receptor interaction, induced the activated phenotype in healthy liver [CD8.sup.+] T cells, resulting in nonspecific Fas ligand-mediated killing of target cells. These results define a [CD8.sup.+] T cell population in the human liver that can drive pathogenesis and a key pathway involved in their function in CHB patients., Introduction Nonspecific activation of memory [CD8.sup.+] T cells is a common feature of acute and chronic human viral diseases (1-7). Bystander-activated [CD8.sup.+] T cells respond in a TCR-independent manner and [...]

In patients with HBV and HCV coinfection, HBV reactivation leading to severe hepatitis has been reported with the use of direct-acting antivirals (DAAs) to treat HCV infection. Here we studied the molecular mechanisms behind this viral interaction. In coinfected cell culture and humanized mice, HBV replication was suppressed by HCV coinfection. In vitro, HBV suppression was attenuated when interferon (IFN) signaling was blocked. In vivo, HBV viremia, after initial suppression by HCV superinfection, rebounded following HCV clearance by DAA treatment that was accompanied by a reduced hepatic IFN response. Using blood samples of coinfected patients, IFN-stimulated gene products including C-X-C motif chemokine 10 (CXCL10), C-C motif chemokine ligand 5 (CCL5), and alanine aminotransferase (ALT) were identified to have predictive value for HBV reactivation after HCV clearance. Taken together, our data suggest that HBV reactivation is a result of diminished hepatic IFN response following HCV clearance and identify serologic markers that can predict HBV reactivation in DAA-treated HBV-HCV-coinfected persons., Introduction Hepatitis B virus (HBV) and hepatitis C virus (HCV) together infect more than 300 million people worldwide. Due to the shared modes of transmission and epidemiological features, they frequently [...]

ImportanceTreatment of hepatitis C virus (HCV) infection in patients also infected with human immunodeficiency virus (HIV) has been limited due to drug interactions with antiretroviral therapies (ARTs) and the need to use interferon.ObjectiveTo determine the rates of HCV eradication (sustained virologic response [SVR]) and adverse events in patients with HCV-HIV coinfection receiving sofosbuvir and ribavirin treatment.Design, setting, and participantsOpen-label, nonrandomized, uncontrolled phase 3 trial conducted at 34 treatment centers in the United States and Puerto Rico (August 2012-November 2013) evaluating treatment with sofosbuvir and ribavirin among patients with HCV genotypes 1, 2, or 3 and concurrent HIV. Patients were required to be receiving ART with HIV RNA values of 50 copies/mL or less and a CD4 T-cell count of more than 200 cells/μL or to have untreated HIV infection with a CD4 T-cell count of more than 500 cells/μL. Of the treatment-naive patients, 114 had HCV genotype 1 and 68 had HCV genotype 2 or 3, and 41 treatment experienced participants who had been treated with peginterferon-ribavirin had HCV genotype 2 or 3, for a total of 223 participants.InterventionsTreatment-naive patients with HCV genotype 2 or 3 received 400 mg of sofosbuvir and weight-based ribavirin for 12 weeks and treatment-naive patients with HCV genotype 1 and treatment-experienced patients with HCV genotype 2 or 3 received the same treatment for 24 weeks.Main outcomes and measuresThe primary study outcome was the proportion of patients with SVR (serum HCV

Hepatitis B virus (HBV) is a major human pathogen that causes immune-mediated hepatitis. Successful immunity to HBV is age dependent: viral clearance occurs in most adults, whereas neonates and young children usually develop chronic infection. Using a mouse model of HBV infection, we sought mechanisms underpinning the age-dependent outcome of HBV and demonstrated that hepatic macrophages facilitate lymphoid organization and immune priming within the adult liver and promote successful immunity. In contrast, lymphoid organization and immune priming was greatly diminished in the livers of young mice, and of macrophage-depleted adult mice, leading to abrogated HBV immunity. Furthermore, we found that CXCL13, which is involved in B lymphocyte trafficking and lymphoid architecture and development, is expressed in an age-dependent manner in both adult mouse and human hepatic macrophages and plays an integral role in facilitating an effective immune response against HBV. Taken together, these results identify some of the immunological mechanisms necessary for effective control of HBV.

Summary: Backgrounds and Aims: We investigated associations between hepatitis B virus (HBV) genome‐length haplotype number (HN) at baseline in subjects with HBeAg‐positive chronic hepatitis B (CHB), and the likelihood of achieving functional cure during direct‐acting antiviral therapy Method: We analysed 86 HBeAg‐positive baseline samples from patients with HBV genotypes A and D who were enrolled in a Phase II trial of tenofovir disoproxil fumarate (TDF) to determine if HN was a biomarker of HBsAg loss during therapy. Findings were validated using baseline samples from 181 patients with HBV genotypes A and D from an independent clinical trial utilising TDF or tenofovir alafenamide therapy in HBeAg‐positive CHB. Results: In the HBeAg‐positive test cohort, patients with genotypes A or D and ≤2 haplotypes had a minimum of 21‐fold higher likelihood of achieving HBsAg loss on TDF. Baseline HN (p < 0.0001) was a stronger predictor of HBsAg loss on therapy than HBsAg titre (p = 0.03), HBeAg titre (p = 0.0002), or the presence of HBV basal core promoter (A1762T, p = 0.0379 and G1764A, p = 0.0176) or G1896A precore mutations (p = 0.0218). This finding was validated in the independent validation cohort. HN was statistically higher in patients with HBV genotypes B or C infection compared to genotypes A and D. Conclusion: Baseline HN ≤2 predicts which patients with HBV genotypes A or D will more likely progress to functional cure on current direct‐acting antiviral therapy, with greater accuracy than current biomarkers including baseline HBsAg and HBeAg titre. [ABSTRACT FROM AUTHOR]

Author(s): Anuj Gaggar [1, 2]; Dmitry M Shayakhmetov [2]; Andre Lieber (corresponding author) [1, 2] Group B adenoviruses, a subgenus of human Adenoviridae, are associated with a variety of often-fatal [...]