Human coronavirus HKU1 recognition of the TMPRSS2 host receptor.

The human coronavirus HKU1 spike (S) glycoprotein engages host cell surface sialoglycans and transmembrane protease serine 2 (TMPRSS2) to initiate infection. The molecular basis of HKU1 binding to TMPRSS2 and determinants of host receptor tropism remain elusive. We designed an active human TMPRSS2 construct enabling high-yield recombinant production in human cells of this key therapeutic target. We determined a cryo-electron microscopy structure of the HKU1 RBD bound to human TMPRSS2, providing a blueprint of the interactions supporting viral entry and explaining the specificity for TMPRSS2 among orthologous proteases. We identified TMPRSS2 orthologs from five mammalian orders promoting HKU1 S-mediated entry into cells along with key residues governing host receptor usage. Our data show that the TMPRSS2 binding motif is a site of vulnerability to neutralizing antibodies and suggest that HKU1 uses S conformational masking and glycan shielding to balance immune evasion and receptor engagement.

SARS-CoV-2 breakthrough infections elicit potent, broad, and durable neutralizing antibody responses.

Although infections among vaccinated individuals lead to milder COVID-19 symptoms relative to those in unvaccinated subjects, the specificity and durability of antibody responses elicited by breakthrough cases remain unknown. Here, we demonstrate that breakthrough infections induce serum-binding and -neutralizing antibody responses that are markedly more potent, durable, and resilient to spike mutations observed in variants than those in subjects who received only 2 doses of vaccine. However, we show that breakthrough cases, subjects who were vaccinated after infection, and individuals vaccinated three times have serum-neutralizing activity of comparable magnitude and breadth, indicating that an increased number of exposures to SARS-CoV-2 antigen(s) enhance the quality of antibody responses. Neutralization of SARS-CoV was moderate, however, underscoring the importance of developing vaccines eliciting broad sarbecovirus immunity for pandemic preparedness.

Spike deep mutational scanning helps predict success of SARS-CoV-2 clades.

SARS-CoV-2 variants acquire mutations in the spike protein that promote immune evasion1 and affect other properties that contribute to viral fitness, such as ACE2 receptor binding and cell entry2,3. Knowledge of how mutations affect these spike phenotypes can provide insight into the current and potential future evolution of the virus. Here we use pseudovirus deep mutational scanning4 to measure how more than 9,000 mutations across the full XBB.1.5 and BA.2 spikes affect ACE2 binding, cell entry or escape from human sera. We find that mutations outside the receptor-binding domain (RBD) have meaningfully affected ACE2 binding during SARS-CoV-2 evolution. We also measure how mutations to the XBB.1.5 spike affect neutralization by serum from individuals who recently had SARS-CoV-2 infections. The strongest serum escape mutations are in the RBD at sites 357, 420, 440, 456 and 473; however, the antigenic effects of these mutations vary across individuals. We also identify strong escape mutations outside the RBD; however, many of them decrease ACE2 binding, suggesting they act by modulating RBD conformation. Notably, the growth rates of human SARS-CoV-2 clades can be explained in substantial part by the measured effects of mutations on spike phenotypes, suggesting our data could enable better prediction of viral evolution.

The forecasted prevalence of comorbidities and multimorbidity in people with HIV in the United States through the year 2030: A modeling study.

BACKGROUND: Estimating the medical complexity of people aging with HIV can inform clinical programs and policy to meet future healthcare needs. The objective of our study was to forecast the prevalence of comorbidities and multimorbidity among people with HIV (PWH) using antiretroviral therapy (ART) in the United States (US) through 2030. METHODS AND FINDINGS: Using the PEARL model-an agent-based simulation of PWH who have initiated ART in the US-the prevalence of anxiety, depression, stage ≥3 chronic kidney disease (CKD), dyslipidemia, diabetes, hypertension, cancer, end-stage liver disease (ESLD), myocardial infarction (MI), and multimorbidity (≥2 mental or physical comorbidities, other than HIV) were forecasted through 2030. Simulations were informed by the US CDC HIV surveillance data of new HIV diagnosis and the longitudinal North American AIDS Cohort Collaboration on Research and Design (NA-ACCORD) data on risk of comorbidities from 2009 to 2017. The simulated population represented 15 subgroups of PWH including Hispanic, non-Hispanic White (White), and non-Hispanic Black/African American (Black/AA) men who have sex with men (MSM), men and women with history of injection drug use and heterosexual men and women. Simulations were replicated for 200 runs and forecasted outcomes are presented as median values (95% uncertainty ranges are presented in the Supporting information). In 2020, PEARL forecasted a median population of 670,000 individuals receiving ART in the US, of whom 9% men and 4% women with history of injection drug use, 60% MSM, 8% heterosexual men, and 19% heterosexual women. Additionally, 44% were Black/AA, 32% White, and 23% Hispanic. Along with a gradual rise in population size of PWH receiving ART-reaching 908,000 individuals by 2030-PEARL forecasted a surge in prevalence of most comorbidities to 2030. Depression and/or anxiety was high and increased from 60% in 2020 to 64% in 2030. Hypertension decreased while dyslipidemia, diabetes, CKD, and MI increased. There was little change in prevalence of cancer and ESLD. The forecasted multimorbidity among PWH receiving ART increased from 63% in 2020 to 70% in 2030. There was heterogeneity in trends across subgroups. Among Black women with history of injection drug use in 2030 (oldest demographic subgroup with median age of 66 year), dyslipidemia, CKD, hypertension, diabetes, anxiety, and depression were most prevalent, with 92% experiencing multimorbidity. Among Black MSM in 2030 (youngest demographic subgroup with median age of 42 year), depression and CKD were highly prevalent, with 57% experiencing multimorbidity. These results are limited by the assumption that trends in new HIV diagnoses, mortality, and comorbidity risk observed in 2009 to 2017 will persist through 2030; influences occurring outside this period are not accounted for in the forecasts. CONCLUSIONS: The PEARL forecasts suggest a continued rise in comorbidity and multimorbidity prevalence to 2030, marked by heterogeneities across race/ethnicity, gender, and HIV acquisition risk subgroups. HIV clinicians must stay current on the ever-changing comorbidities-specific guidelines to provide guideline-recommended care. HIV clinical directors should ensure linkages to subspecialty care within the clinic or by referral. HIV policy decision-makers must allocate resources and support extended clinical capacity to meet the healthcare needs of people aging with HIV.

Deep mutational scans for ACE2 binding, RBD expression, and antibody escape in the SARS-CoV-2 Omicron BA.1 and BA.2 receptor-binding domains.

SARS-CoV-2 continues to acquire mutations in the spike receptor-binding domain (RBD) that impact ACE2 receptor binding, folding stability, and antibody recognition. Deep mutational scanning prospectively characterizes the impacts of mutations on these biochemical properties, enabling rapid assessment of new mutations seen during viral surveillance. However, the effects of mutations can change as the virus evolves, requiring updated deep mutational scans. We determined the impacts of all single amino acid mutations in the Omicron BA.1 and BA.2 RBDs on ACE2-binding affinity, RBD folding, and escape from binding by the LY-CoV1404 (bebtelovimab) monoclonal antibody. The effects of some mutations in Omicron RBDs differ from those measured in the ancestral Wuhan-Hu-1 background. These epistatic shifts largely resemble those previously seen in the Alpha variant due to the convergent epistatically modifying N501Y substitution. However, Omicron variants show additional lineage-specific shifts, including examples of the epistatic phenomenon of entrenchment that causes the Q498R and N501Y substitutions present in Omicron to be more favorable in that background than in earlier viral strains. In contrast, the Omicron substitution Q493R exhibits no sign of entrenchment, with the derived state, R493, being as unfavorable for ACE2 binding in Omicron RBDs as in Wuhan-Hu-1. Likely for this reason, the R493Q reversion has occurred in Omicron sub-variants including BA.4/BA.5 and BA.2.75, where the affinity buffer from R493Q reversion may potentiate concurrent antigenic change. Consistent with prior studies, we find that Omicron RBDs have reduced expression, and identify candidate stabilizing mutations that ameliorate this deficit. Last, our maps highlight a broadening of the sites of escape from LY-CoV1404 antibody binding in BA.1 and BA.2 compared to the ancestral Wuhan-Hu-1 background. These BA.1 and BA.2 deep mutational scanning datasets identify shifts in the RBD mutational landscape and inform ongoing efforts in viral surveillance.

The Anatomy Act 1977 (NSW) Dissected: Review and Reform.

This column discusses the Anatomy Act 1977 (NSW) and its regulatory environment. The column begins with examining the history of anatomy regulation in the United Kingdom and Australia. It then goes on to analyse the history of the current anatomy regulation in New South Wales, pointing out areas for reform.

Sexual Boundary Violations by Doctors - Context, Regulatory Consequences and Preventive Strategies.

While sexual boundary violations by doctors (SBVs) are viewed with utmost seriousness by disciplinary bodies and tribunals, complaints of SBVs in Australia continue to increase. In 2023, the Australian Health Practitioner Regulation Agency (Ahpra) outlined a "blueprint" to protect patients better from sexual misconduct in healthcare: reform being considered in 2024, by Australian health ministers. Few analyses or studies have offered an overview of the prevalence, effects, and causes of SBVs, nor the duties, liabilities, possible disciplinary action against, and potential treatment of, doctors who commit them. This column offers such an overview, and considers, additionally, whether doctors who may have psychiatric disorders associated with their boundary violations would be suitable candidates for treatment. Ultimately, we contend that a purely "responsive" approach is inadequate, and preventive measures such as screening and more effective education should be considered in medical schools as a way of reducing the incidence of SBVs.

A Growing Number of Men Who Have Sex With Men Aging With HIV (20212031): A Comparison of Two Microsimulation Models.

BACKGROUND: Men who have sex with men (MSM) on antiretroviral therapy (ART) are at risk for multimorbidity as life expectancy increases. Simulation models can project population sizes and age distributions to assist with health policy planning. METHODS: We populated the CEPAC-US model with CDC data to project the HIV epidemic among MSM in the United States. The PEARL model was predominantly informed by NA-ACCORD data (20092017). We compared projected population sizes and age distributions of MSM receiving ART (20212031) and investigated how parameters and assumptions affected results. RESULTS: We projected an aging and increasing population of MSM on ART: CEPAC-US, mean age 48.6 (SD 13.7) years in 2021 versus 53.9 (SD 15.0) years in 2031; PEARL, 46.7 (SD 13.2) years versus 49.2 (SD 14.6) years. We projected 548 800 MSM on ART (147 020 65 years) in 2031 (CEPAC-US) and 599 410 (113 400 65 years) (PEARL). Compared with PEARL, CEPAC-US projected a smaller population of MSM on ART by 2031 and a slower increase in population size, driven by higher estimates of disengagement in care and mortality. CONCLUSIONS: Findings from two structurally distinct microsimulation models suggest that the MSM population receiving ART in the United States will increase and age over the next decade. Subgroup-specific data regarding engagement in care and mortality can improve projections and inform health care policy planning.

Money matters: a critique of 'informed financial consent'.

In recent years, concerns about the financial burdens of health care and growing recognition of the relevance of cost to decision making and patient experience have increasingly focused attention on financial 'transparency' and disclosure of costs to patients. In some jurisdictions, there have been calls not only for timely disclosure of costs information, but also for 'informed financial consent'. However, simply putting the 'financial' into 'informed consent' and invoking an informed consent standard for cost information encounters several ethical, legal, and practical difficulties. This article will examine the viability and desirability of 'informed financial consent', and whether it is possible to derive ideas from traditional informed consent that may improve decision making and the patient experience. We argue that, while there are important legal, ethical, and practical challenges to consider, some of the principles of informed consent to treatment can usefully guide financial communication. We also argue that, while medical practitioners (and their delegates) have an important role to play in bridging the gap between disclosure and enabling informed (financial) decision making, this must be part of a multi-faceted approach to financial communication that acknowledges the influence of non-clinical providers and other structural forces on discharging such obligations.

Addressing the consequences of the corporatization of reproductive medicine.

In Australia and the UK, commercialization and corporatization of assisted reproductive technologies have created a marketplace of clinics, products, and services. While this has arguably increased choice for patients, 'choice', shaped by commercial imperatives may not mean better-quality care. At present, regulation of clinics (including clinic-corporations) and clinicians focuses on the doctor-patient dyad and the clinic-consumer dyad. Scant attention has been paid to the conflicts between the clinic-corporation's duty to its shareholders and investors, the medical profession's duty to the corporations within which they practice, and the obligations of both clinicians and corporations to patients and to health systems. Frameworks of regulation based in corporate governance and business ethics, such as stakeholder models and 'corporate social responsibility', have well-recognized limits and may not translate well into healthcare settings. This means that existing governance frameworks may not meet the needs of patients or health systems. We argue for the development of novel regulatory approaches that more explicitly characterize the obligations that both corporations and clinicians in corporate environments have to patients and to society, and that promote fulfilment of these obligations. We consider mechanisms for application in the multi-jurisdictional setting of Australia, and the single jurisdictional settings of the UK.

Altered microRNA expression in COVID-19 patients enables identification of SARS-CoV-2 infection.

The host response to SARS-CoV-2 infection provide insights into both viral pathogenesis and patient management. The host-encoded microRNA (miRNA) response to SARS-CoV-2 infection, however, remains poorly defined. Here we profiled circulating miRNAs from ten COVID-19 patients sampled longitudinally and ten age and gender matched healthy donors. We observed 55 miRNAs that were altered in COVID-19 patients during early-stage disease, with the inflammatory miR-31-5p the most strongly upregulated. Supervised machine learning analysis revealed that a three-miRNA signature (miR-423-5p, miR-23a-3p and miR-195-5p) independently classified COVID-19 cases with an accuracy of 99.9%. In a ferret COVID-19 model, the three-miRNA signature again detected SARS-CoV-2 infection with 99.7% accuracy, and distinguished SARS-CoV-2 infection from influenza A (H1N1) infection and healthy controls with 95% accuracy. Distinct miRNA profiles were also observed in COVID-19 patients requiring oxygenation. This study demonstrates that SARS-CoV-2 infection induces a robust host miRNA response that could improve COVID-19 detection and patient management.

The Standard of Care Test Revisited: Competing Approaches to Defining Competent Profession Practice in Australia.

This section examines the recent decision of the New South Wales Court of Appeal in Dean v Pope [2022] NSWCA 260. The decision settles a long-running dispute in New South Wales about the test for the standard of care under s 5O of the Civil Liability Act 2002 (NSW). That provision was introduced following the medical indemnity crisis of the early 2000s and provided for a modified Bolam test to protect professionals from claims in negligence when they had acted in accordance with a standard of "competent professional practice". In recent years there has been controversy regarding whether that section required the practice to be one already established to satisfy the section. This section examines the decision, how it fits into the history of the Ipp reforms and what it means for other jurisdictions in Australia.

Lessons from Re Teo: Unconventional Practice and the National Law.

This section explores the decision of the New South Wales Professional Standards Committee, in Re Teo [2023] NSWMPSC 2. The case provides insights into how the Health Practitioner Regulation National Law Act 2009 (Qld) regulates practitioners who practise outside of conventional practice. The section compares the decision to similar cases and then concludes with a proposal that an express policy on unconventional practice is needed in Australia.

Conscientious Objection and Institutional Objection to Voluntary Assistance in Dying: An Ethico-legal Critique.

This column examines conscientious objection and institutional objection in Australian voluntary assistance in dying. It reviews the current legislative regimes and then examines these practices from an ethical perspective, and raises particular concerns and suggestions with how conscientious objection and institutional objection should be operationalised.

ILRUN Downregulates ACE2 Expression and Blocks Infection of Human Cells by SARS-CoV-2.

The human protein-coding gene ILRUN (inflammation and lipid regulator with UBA-like and NBR1-like domains; previously C6orf106) was identified as a proviral factor for Hendra virus infection and was recently characterized to function as an inhibitor of type I interferon expression. Here, we have utilized transcriptome sequencing (RNA-seq) to define cellular pathways regulated by ILRUN in the context of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection of Caco-2 cells. We find that inhibition of ILRUN expression by RNA interference alters transcription profiles of numerous cellular pathways, including upregulation of the SARS-CoV-2 entry receptor ACE2 and several other members of the renin-angiotensin aldosterone system. In addition, transcripts of the SARS-CoV-2 coreceptors TMPRSS2 and CTSL were also upregulated. Inhibition of ILRUN also resulted in increased SARS-CoV-2 replication, while overexpression of ILRUN had the opposite effect, identifying ILRUN as a novel antiviral factor for SARS-CoV-2 replication. This represents, to our knowledge, the first report of ILRUN as a regulator of the renin-angiotensin-aldosterone system (RAAS). IMPORTANCE There is no doubt that the current rapid global spread of COVID-19 has had significant and far-reaching impacts on our health and economy and will continue to do so. Research in emerging infectious diseases, such as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is growing rapidly, with new breakthroughs in the understanding of host-virus interactions to assist with the development of innovative and exciting therapeutic strategies. Here, we present the first evidence that modulation of the human protein-coding gene ILRUN functions as an antiviral factor for SARS-CoV-2 infection, likely through its newly identified role in regulating the expression of SARS-CoV-2 entry receptors ACE2, TMPRSS2, and CTSL. These data improve our understanding of biological pathways that regulate host factors critical to SARS-CoV-2 infection, contributing to the development of antiviral strategies to deal with the current SARS-CoV-2 pandemic.

CD36 ligands promote sterile inflammation through assembly of a Toll-like receptor 4 and 6 heterodimer.

In atherosclerosis and Alzheimer's disease, deposition of the altered self components oxidized low-density lipoprotein (LDL) and amyloid-beta triggers a protracted sterile inflammatory response. Although chronic stimulation of the innate immune system is believed to underlie the pathology of these diseases, the molecular mechanisms of activation remain unclear. Here we show that oxidized LDL and amyloid-beta trigger inflammatory signaling through a heterodimer of Toll-like receptors 4 and 6. Assembly of this newly identified heterodimer is regulated by signals from the scavenger receptor CD36, a common receptor for these disparate ligands. Our results identify CD36-TLR4-TLR6 activation as a common molecular mechanism by which atherogenic lipids and amyloid-beta stimulate sterile inflammation and suggest a new model of TLR heterodimerization triggered by coreceptor signaling events.

Death determination, organ donation and the importance of the Dead Donor Rule following withdrawal of life-sustaining treatment: a survey of community opinions.

BACKGROUND: Background: Organ donation (OD) following circulatory determination of death (DCDD) is an increasing source of transplant organs but little is known about community opinions on treatment withdrawal, determination of death and acceptance of OD in DCDD. AIMS: To determine attitudes on death determination in DCDD, the importance of patient choice in treatment withdrawal and OD agreement, and the importance of the 'Dead Donor Rule'. METHODS: Scenario-based online survey of 1017 members of the Australian general public. Mean levels of agreement across respondent's responses to statements were compared by repeated measures ANOVA. RESULTS: 54% (548) of respondents agreed that a DCDD scenario patient could be declared dead 2 minutes after circulatory standstill, however over 80% nonetheless agreed OD would be appropriate, including 77% (136/176) of those disagreeing with a 2-minute death declaration. 48% (484) supported OD even if it caused the patient's death. 75% (766) would accept relatively benign ante-mortem treatments administered to improve transplant outcomes. Over 70% supported a high quadriplegic patient's request to be allowed to die, with 61% (622) agreeing that he should be allowed to donate his organs under anaesthesia, but 60% (610) also agreed that he should first be declared dead. CONCLUSIONS: We found high levels of support for treatment withdrawal in severe brain injury and when requested by a quadriplegic patient. While there was variable agreement with the timing of death determination and with OD under anaesthesia, support for OD was high in both scenarios. For many people death determination prior to OD may not be of paramount importance.

Throwing a Cat among the Pridgeon(s): The New South Wales Court of Appeal and the Public Interest Test under the Health Practitioner Regulation National Law.

This section examines the 2022 decision of Pridgeon v Medical Council of New South Wales in the New South Wales Court of Appeal that has taken a fundamentally different view of the public interest test employed in immediate action hearings under the Health Practitioner Regulation National Law. The section starts by examining the case and then looks at the approach taken by subsequent decisions. It will argue that the decision is substantially at odds with earlier authorities from all around Australia and fails to understand properly the meaning and purpose of the test.

Negligence and Health Innovation: Issues with the Standard of Care and the Need to Revisit the Voluntary Assumption of Risk.

This section examines current debates about the test for standards of care in negligence under the Civil Liability Acts in Australia, and how those debates may impact adversely on innovations in health care. It examines the recent history of attempts to define and regulate health innovation and compares them to judicial determinations from New South Wales that have potential to limit the protections otherwise afforded to competent professional practice. The section argues that, if those protections are eroded, alternative options to protect and encourage innovation should be explored, most especially a resuscitated defence of the voluntary assumption of risk.

Is PTSD a Bodily Injury?

Post-traumatic stress disorder (PTSD) is unique among psychiatric disorders in that the cause, a traumatic event (or events), is known. PTSD is often the subject of legal proceedings, with persons seeking compensation from the agency considered responsible for the trauma. While PTSD is clearly a psychiatric disorder, there is less agreement about whether PTSD can also be categorised as a bodily injury, as defined by the Montreal Convention 1999. This article describes Pel-Air Pty Ltd v Casey, a case involving physical and psychiatric injuries resulting from the forced landing of a plane. It was ruled that PTSD was not a bodily injury under the Convention. While psychiatric expert evidence demonstrated that PTSD causes neurochemical changes, it was ruled that neurochemical changes do not indicate a bodily injury. We describe evidence of neuroanatomical changes and neurochemical changes in PTSD, proposing that the structure of the brain in PTSD support the argument that PTSD is a bodily injury.