Virus-Induced Acute Respiratory Distress Syndrome Causes Cardiomyopathy Through Eliciting Inflammatory Responses in the Heart

Circulation, Ahead of Print. BACKGROUND:Viral infections can cause acute respiratory distress syndrome (ARDS), systemic inflammation, and secondary cardiovascular complications. Lung macrophage subsets change during ARDS, but the role of heart macrophages in cardiac injury during viral ARDS remains unknown. Here we investigate how immune signals typical for viral ARDS affect cardiac macrophage subsets, cardiovascular health, and systemic inflammation.METHODS:We assessed cardiac macrophage subsets using immunofluorescence histology of autopsy specimens from 21 patients with COVID-19 with SARS-CoV-2–associated ARDS and 33 patients who died from other causes. In mice, we compared cardiac immune cell dynamics after SARS-CoV-2 infection with ARDS induced by intratracheal instillation of Toll-like receptor ligands and an ACE2 (angiotensin-converting enzyme 2) inhibitor.RESULTS:In humans, SARS-CoV-2 increased total cardiac macrophage counts and led to a higher proportion of CCR2+(C-C chemokine receptor type 2 positive) macrophages. In mice, SARS-CoV-2 and virus-free lung injury triggered profound remodeling of cardiac resident macrophages, recapitulating the clinical expansion of CCR2+macrophages. Treating mice exposed to virus-like ARDS with a tumor necrosis factor α–neutralizing antibody reduced cardiac monocytes and inflammatory MHCIIloCCR2+macrophages while also preserving cardiac function. Virus-like ARDS elevated mortality in mice with pre-existing heart failure.CONCLUSIONS:Our data suggest that viral ARDS promotes cardiac inflammation by expanding the CCR2+macrophage subset, and the associated cardiac phenotypes in mice can be elicited by activating the host immune system even without viral presence in the heart.

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Marzo 2024

New facet of CARs: HBV-specific CARs as inhibitors of virus morphogenesis and release

Although safe and effective vaccines against HBV (hepatitis B virus) are available, there are worldwide more than 2 billion people who had an HBV infection and about 250 million people suffering from chronic HBV infection. Chronic HBV infection is a major cause for liver diseases such as fibrosis, cirrhosis and hepatocellular carcinoma (HCC). It is estimated that about 800 000–1 000 000 people die each year due to the consequences of chronic HBV infection.1 Moreover, in almost all HBV-associated HCCs integrated HBV-DNA is found. Therapy options at present are limited and based on nucleoside/nucleotide analogues and interferon alpha. Since persistence of HBV infection frequently can be attributed to an insufficient cellular immune response approaches to rescue host immune response may help to eliminate infected cells and to suppress virus replication. A recent development are HBV-specific CARs (chimeric antigen receptors) human T-cells that are intended to recognise and eliminate HBV positive…

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Marzo 2024

Prevalence of hepatitis B virus infection among general population of Armenia in 2021 and factors associated with it: a cross-sectional study

Objectives
This study sought to determine the prevalence and associated factors of hepatitis B virus (HBV) infection ever in life and chronic HBV infection in Armenia.

Design
A population-based cross-sectional seroprevalence study combined with a phone survey of tested individuals.

Setting
All administrative units of Armenia including 10 provinces and capital city Yerevan.

Participants
The study frame was the general adult population of Armenia aged ≥18 years.

Primary and secondary outcome measures
The participants were tested for anti-HBV core antibodies (anti-HBc) and HBV surface antigen (HBsAg) using third-generation enzyme immunoassays. In case of HBsAg positivity, HBV DNA and hepatitis D virus (HDV) RNA PCR tests were performed. Risk factors of HBV infection ever in life (anti-HBc positivity) and chronic HBV infection (HBsAg positivity) were identified through fitting logistic regression models.

Results
The seroprevalence study included 3838 individuals 18 years and older. Of them, 90.7% (3476 individuals) responded to the phone survey. The prevalence of anti-HBc positivity was 14.1% (95% CI 13.1% to 15.2%) and HBsAg positivity 0.8% (95% CI 0.5% to 1.1%). The viral load was over 10 000 IU/mL for 7.9% of HBsAg-positive individuals. None of the participants was positive for HDV. Risk factors for HBsAg positivity included less than secondary education (aOR=6.44; 95% CI 2.2 to 19.1), current smoking (aOR=2.56; 95% CI 1.2 to 5.6), and chronic liver disease (aOR=8.44; 95% CI 3.0 to 23.7). In addition to these, risk factors for anti-HBc positivity included age (aOR=1.04; 95% CI 1.04 to 1.05), imprisonment ever in life (aOR=2.53; 95% CI 1.41 to 4.56), and poor knowledge on infectious diseases (aOR=1.32; 95% CI 1.05 to 1.67), while living in Yerevan (vs provinces) was protective (aOR=0.74; 95% CI 0.59 to 0.93).

Conclusion
This study provided robust estimates of HBV markers among general population of Armenia. Its findings delineated the need to revise HBV testing and treatment strategies considering higher risk population groups, and improve population knowledge on HBV prevention.

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Febbraio 2024

Seroprevalence of Japanese encephalitis virus-specific antibodies in Australia following novel epidemic spread: protocol for a national cross-sectional study

Introduction
Japanese encephalitis virus (JEV) is a mosquito-borne flavivirus that causes encephalitis and other morbidity in Southeast Asia. Since February 2022, geographically dispersed JEV human, animal and vector detections occurred on the Australian mainland for the first time. This study will determine the prevalence of JEV-specific antibodies in human blood with a focus on populations at high risk of JEV exposure and determine risk factors associated with JEV seropositivity by location, age, occupation and other factors.

Method
Samples are collected using two approaches: from routine blood donors (4153 samples), and active collections targeting high-risk populations (convenience sampling). Consent-based sampling for the latter includes a participant questionnaire on demographic, vaccination and exposure data. Samples are tested for JEV-specific total antibody using a defined epitope-blocking ELISA, and total antibody to Australian endemic flaviviruses Murray Valley encephalitis and Kunjin viruses.

Analysis
Two analytic approaches will occur: descriptive estimates of seroprevalence and multivariable logistic regression using Bayesian hierarchical models. Descriptive analyses will include unadjusted analysis of raw data with exclusions for JEV-endemic country of birth, travel to JEV-endemic countries, prior JEV-vaccination, and sex-standardised and age-standardised analyses. Multivariable logistic regression will determine which risk factors are associated with JEV seropositivity likely due to recent transmission within Australia and the relative contribution of each factor when accounting for effects within the model.

Ethics
National Mutual Acceptance ethical approval was obtained from the Sydney Children’s Hospitals Network Human Research Ethics Committee (HREC). Local approvals were sought in each jurisdiction. Ethical approval was also obtained from the Australian Red Cross Lifeblood HREC.

Dissemination
Findings will be communicated to participants and their communities, and human and animal health stakeholders and policy-makers iteratively and after final analyses. Understanding human infection rates will inform procurement and targeted allocation of limited JEV vaccine, and public health strategies and communication campaigns, to at-risk populations.

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Febbraio 2024

Abstract TMP8: Varicella Zoster Virus Infection in Children With Arterial Ischemic Stroke: The Chicken or the Egg?

Stroke, Volume 55, Issue Suppl_1, Page ATMP8-ATMP8, February 1, 2024. Introduction:Serologic evidence of varicella zoster virus (VZV) infection has been associated with childhood arterial ischemic stroke (AIS). Questions of causality persist: does VZV infection cause AIS, or does AIS reactivate VZV? The Vascular effects of Infection in Pediatric Stroke (VIPS II) study aimed to examine this relationship.Methods:This North American 22-center prospective cohort study enrolled 205 children (28 days-18 years) with AIS (2017-2022). Blood samples were hyperacute (≤72hrs; n=194), acute (4-7 days; n=180) and convalescent (1-6 weeks; n=73). A virology research lab used ELISA to measure VZV IgM and IgG titers. A pediatric virologist (CG) interpreted the results and classified the evidence of infection. Low-level IgG seropositivity is consistent with prior vaccination/infection. Highly elevated IgM in hyperacute/acute samples indicatedreactivationcoincident withstroke. Rising IgG titers between hyperacute and convalescent samples, occasionally with a high IgM in convalescent sample, indicatedreactivationafterthe stroke.Results:Median age (IQR) was 11.6 years (5.3, 15.6). All 205 cases were low-level IgG positive; 160 (78%) reported prior VZV vaccination and 3 reported remote chicken pox. Serologies for 15 (7.3%; 95% CI 4.1, 11.8%) indicated VZV reactivation coincident with stroke; prior VZV vaccination reported in 14 and unknown in one. Stroke etiology amongst these 15 was definite arteriopathy in 4 (27%), possible arteriopathy in 4 (27%), cardioembolic in 5 (33%), and idiopathic in 2 (13%) (compared to 37%, 37%, 10%, 14%, respectively, for the other 190). Among 73 with convalescent samples, 17 (23%) had VZV reactivation after stroke. All cases of VZV reactivation were asymptomaticzoster sine herpete(herpes zoster without rash).Conclusions:While stroke triggered VZV reactivation in 23% of cases, 7.3% had evidence ofzoster sine herpeteat the time of their stroke, implying a causal role. We could not distinguish antibodies to vaccine virus versus wild-type; these zoster cases could represent reactivation of vaccine virus or a break-through wild-type varicella infection. Either scenario would be unexpected in this current era of routine childhood VZV vaccination and low rates of pediatric chicken pox or zoster.

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Febbraio 2024