8 research outputs found

    Cytomegaloviral determinants of CD8+ T cell programming and RhCMV/SIV vaccine efficacy

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    Simian immunodeficiency virus (SIV) insert-expressing, 68–1 Rhesus Cytomegalovirus (RhCMV/SIV) vectors elicit major histocompatibility complex (MHC)-E- and -II-restricted, SIV-specific CD8(+) T cell responses, but the basis of these unconventional responses and their contribution to demonstrated vaccine efficacy against SIV challenge in the rhesus monkeys (RMs) has not been characterized. We show that these unconventional responses resulted from a chance genetic rearrangement in 68–1 RhCMV that abrogated the function of eight distinct immunomodulatory gene products encoded in two RhCMV genomic regions (Rh157.5/Rh157.4 and Rh158–161), revealing three patterns of unconventional response inhibition. Differential repair of these genes with either RhCMV-derived or orthologous human CMV (HCMV)-derived sequences (UL128/UL130; UL146/UL147) leads to either of two distinct CD8(+) T cell response types – MHC-Ia-restricted-only, or a mix of MHC-II- and MHC-Ia-restricted CD8(+) T cells. Response magnitude and functional differentiation are similar to RhCMV 68–1, but neither alternative response type mediated protection against SIV challenge. These findings implicate MHC-E-restricted CD8(+) T cell responses as mediators of anti-SIV efficacy and indicate that translation of RhCMV/SIV vector efficacy to humans will likely require deletion of all genes that inhibit these responses from the HCMV/HIV vector

    The Australasian COVID-19 Trial (ASCOT) to assess clinical outcomes in hospitalised patients with SARS-CoV-2 infection (COVID-19) treated with lopinavir/ritonavir and/or hydroxychloroquine compared to standard of care: A structured summary of a study protocol for a randomised controlled trial

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    Objectives: To determine if lopinavir/ritonavir +/- hydroxychloroquine will reduce the proportion of participants who survive without requiring ventilatory support, 15 days after enrolment, in adult participants with non-critically ill SARS-CoV-2 infection. Trial design: ASCOT is an investigator-initiated, multi-centre, open-label, randomised controlled trial. Participants will have been hospitalised with confirmed COVID-19, and will be randomised 1:1:1:1 to receive lopinavir /ritonavir, hydroxychloroquine, both or neither drug in addition to standard of care management. Participants: Participants will be recruited from >80 hospitals across Australia and New Zealand, representing metropolitan and regional centres in both public and private sectors. Admitted patients will be eligible if aged ≥ 18 years, have confirmed SARS-CoV-2 by nucleic acid testing in the past 12 days and are expected to remain an inpatient for at least 48 hours from the time of randomisation. Potentially eligible participants will be excluded if admitted to intensive care or requiring high level respiratory support, are currently receiving study drugs or their use is contraindicated due to allergy, drug interaction or comorbidities (including baseline QTc prolongation of 470ms for women or 480ms for men), or death is anticipated imminently

    Thrombotic microangiopathy from Australian brown snake (Pseudonaja) envenoming.

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    Background: Australian brown snake (genus Pseudonaja) envenoming causes a venom-induced consumptive coagulopathy (VICC). A proportion of cases go on to develop thrombotic microangiopathy characterized by thrombocytopenia, microangiopathic haemolytic anaemia (MAHA) and acute renal failure (ARF).\ud \ud Aim: The aim of the study was to define better the natural history and empirical treatments for thrombotic microangiopathy in brown snake envenoming.\ud \ud Methods: A review of brown snake bites recruited to the Australian Snakebite Project (ASP), a national multicentre study of snake envenoming was undertaken. Serial data are recorded on clinical effects and laboratory results, including measurement of venom concentrations. We describe cases of thrombotic microangiopathy and compare these to cases without thrombotic microangiopathy.\ud \ud Results: From 32 cases of brown snake envenoming with severe VICC, four (13%) developed thrombotic microangiopathy, we also included two cases of thrombotic microangiopathy from prior to ASP. All six developed severe thrombocytopenia (<20 × 10−9/L), worst 3 days after the bite and resolving over a week, MAHA with fragmented red blood cells on the blood film and five developed anuric ARF requiring dialysis and lasting 2–8 weeks. All six received antivenom, which was delayed compared with other brown snake-envenoming cases. Four were treated with plasmapheresis. The severity and recovery of the thrombocytopenia, anaemia and renal function were similar with and without plasmapheresis. The median length of stay for MAHA cases was 14 days (interquartile range (IQR) 12–14) compared to 1.8 days (IQR 1.3–2) for all other cases.\ud \ud Conclusion:  Thrombotic microangiopathy resulting from brown snake bite appears to have a good prognosis and management should focus on early antivenom therapy and supportive care including dialysis. The role of plasmapheresis is yet to be defined

    The Australasian Resuscitation In Sepsis Evaluation: Fluids or vasopressors in emergency department sepsis (ARISE FLUIDS), a multi-centre observational study describing current practice in Australia and New Zealand

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    OBJECTIVES: To describe haemodynamic resuscitation practices in ED patients with suspected sepsis and hypotension. METHODS: This was a prospective, multicentre, observational study conducted in 70 hospitals in Australia and New Zealand between September 2018 and January 2019. Consecutive adults presenting to the ED during a 30-day period at each site, with suspected sepsis and hypotension (systolic blood pressure <100 mmHg) despite at least 1000 mL fluid resuscitation, were eligible. Data included baseline demographics, clinical and laboratory variables and intravenous fluid volume administered, vasopressor administration at baseline and 6- and 24-h post-enrolment, time to antimicrobial administration, intensive care admission, organ support and in-hospital mortality. RESULTS: A total of 4477 patients were screened and 591 were included with a mean (standard deviation) age of 62 (19) years, Acute Physiology and Chronic Health Evaluation II score 15.2 (6.6) and a median (interquartile range) systolic blood pressure of 94 mmHg (87-100). Median time to first intravenous antimicrobials was 77 min (42-148). A vasopressor infusion was commenced within 24 h in 177 (30.2%) patients, with noradrenaline the most frequently used (n = 138, 78%). A median of 2000 mL (1500-3000) of intravenous fluids was administered prior to commencing vasopressors. The total volume of fluid administered from pre-enrolment to 24 h was 4200 mL (3000-5661), with a range from 1000 to 12 200 mL. Two hundred and eighteen patients (37.1%) were admitted to an intensive care unit. Overall in-hospital mortality was 6.2% (95% confidence interval 4.4-8.5%). CONCLUSION: Current resuscitation practice in patients with sepsis and hypotension varies widely and occupies the spectrum between a restricted volume/earlier vasopressor and liberal fluid/later vasopressor strategy

    The Australasian COVID-19 Trial (ASCOT) to assess clinical outcomes in hospitalised patients with SARS-CoV-2 infection (COVID-19) treated with lopinavir/ritonavir and/or hydroxychloroquine compared to standard of care: A structured summary of a study protocol for a randomised controlled trial

    No full text
    Objectives: To determine if lopinavir/ritonavir +/- hydroxychloroquine will reduce the proportion of participants who survive without requiring ventilatory support, 15 days after enrolment, in adult participants with non-critically ill SARS-CoV-2 infection. Trial design: ASCOT is an investigator-initiated, multi-centre, open-label, randomised controlled trial. Participants will have been hospitalised with confirmed COVID-19, and will be randomised 1:1:1:1 to receive lopinavir /ritonavir, hydroxychloroquine, both or neither drug in addition to standard of care management. Participants: Participants will be recruited from >80 hospitals across Australia and New Zealand, representing metropolitan and regional centres in both public and private sectors. Admitted patients will be eligible if aged ≥ 18 years, have confirmed SARS-CoV-2 by nucleic acid testing in the past 12 days and are expected to remain an inpatient for at least 48 hours from the time of randomisation. Potentially eligible participants will be excluded if admitted to intensive care or requiring high level respiratory support, are currently receiving study drugs or their use is contraindicated due to allergy, drug interaction or comorbidities (including baseline QTc prolongation of 470ms for women or 480ms for men), or death is anticipated imminently. Intervention and comparator: Participants will be randomised 1:1:1:1 to: Group 1: standard of care; Group 2: lopinavir (400mg) / ritonavir (100mg) twice daily for 10 days in tablet form; Group 3: hydroxychloroquine (800mg) 4x200mg administered 12 hours apart on Day 1, followed by 400mg twice a day for 6 days; Group 4: lopinavir /ritonavir plus hydroxychloroquine. Main outcomes: Proportion of participants alive and not having required intensive respiratory support (invasive or non-invasive ventilation) at 15 days after enrolment. A range of clinical and virological secondary outcomes will also be evaluated. Randomisation: The randomisation schedule will be generated by an independent statistician. Randomisation will be stratified by site and will be in permuted blocks of variable block size. The randomised sequence allocation will only be accessible to the data management group, and site investigators will have individual participant allocation provided through a web-based trial enrolment platform. Blinding (masking): This is an open-label study, with researchers assessing the laboratory outcomes blinded to treatment allocation. No unblinding procedures relating to potential adverse effects are therefore required. Numbers to be randomised (sample size): We assumed that 5% of participants receiving standard of care would meet the primary outcome, aimed to evaluate whether interventions could lead to a relative risk of 0.5, assuming no interaction between intervention arms. This corresponds to a required sample size of 610 per arm, with a 5% two-sided significance level (alpha) and 80% power. The total sample size therefore is planned to be 2440. Trial Status: ASCOT protocol version 3, May 5, 2020. Recruitment opened April 4, 2020 and is ongoing, with planned completion of enrolment July 31, 2021. Trial registration: Australian New Zealand Clinical Trials Registry (ACTRN12620000445976). Prospectively registered April 6, 2020. Full protocol: The full protocol is attached as an additional file, accessible from the Trials website (Additional file 1). In the interest in expediting dissemination of this material, the familiar formatting has been eliminated; this Letter serves as a summary of the key elements of the full protocol

    Gender differences in mortality and quality of life after septic shock: A post-hoc analysis of the ARISE study

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    PURPOSE: To assess the impact of gender and pre-menopausal state on short- and long-term outcomes in patients with septic shock. MATERIAL AND METHODS: Cohort study of the Australasian Resuscitation in Sepsis Evaluation (ARISE) trial, an international randomized controlled trial comparing early goal-directed therapy (EGDT) to usual care in patients with early septic shock, conducted between October 2008 and April 2014. The primary exposure in this analysis was legal gender and the secondary exposure was pre-menopausal state defined by chronological age (≤ 50 years). RESULTS: 641 (40.3%) of all 1591 ARISE trial participants in the intention-to-treat population were females and overall, 337 (21.2%) (146 females) patients were 50  years of age or younger. After risk-adjustment, we could not identify any survival benefit for female patients at day 90 in the younger (≤50 years) (adjusted Odds Ratio (aOR): 0.91 (0.46-1.89), p = .85) nor in the older (>50 years) age-group (aOR: 1.10 (0.81-1.49), p = .56). Similarly, there was no gender-difference in ICU, hospital, 1-year mortality nor quality of life measures. CONCLUSIONS: This post-hoc analysis of a large multi-center trial in early septic shock has shown no short- or long-term survival effect for women overall as well as in the pre-menopausal age-group
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