Publications by authors named "Olivia C Smibert"

Background: Limited data exist regarding outcomes of cryptococcosis in patients without HIV with few studies having compared outcomes of Cryptococcus gattii, versus C. neoformans, infection.

Methods: We conducted a retrospective study in 46 Australian and New Zealand hospitals to determine the outcomes of cryptococcosis in patients without HIV diagnosed between 2015 and 2019, and compared outcomes of C.

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Introduction: The human gut microbiota has the potential to modulate the outcomes of several human diseases. This effect is likely to be mediated through interaction with the host immune system. This protocol details the establishment of a biorepository of clinically annotated samples, which we will use to explore correlations between the gut microbiota and the immune system of immune-compromised patients.

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Background: Despite the burden of pyelonephritis after kidney transplantation, there is no consensus on initial empirical antibiotic management.

Methods: We surveyed clinicians throughout the world on their practice and opinions about the initial empirical therapy of post-transplant pyelonephritis, using clinical vignettes. A panel of experts from 19 countries on six continents designed this survey, and invited 2145 clinicians to participate.

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Article Synopsis
  • A multicenter study examined the effects of adjunctive glucocorticoid therapy (AGT) on all-cause ICU admission and death rates among solid organ transplant recipients (SOTRs) with Pneumocystis jirovecii pneumonia (PJP) across several countries.
  • The study included 172 SOTRs with an average age of 60, and found ICU admission rates at 43.4% and death rates at 20.8%.
  • Results showed that AGT did not significantly lower the risk of ICU admission, death, or improve respiratory function, indicating a need to reconsider its routine use in PJP treatment for SOTRs and call for further research.
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We used a next-generation sequencing platform to characterize microbial cell-free DNA (mcfDNA) in plasma samples from patients undergoing allogeneic hematopoietic stem cell transplantation (allo-HCT). In this observational study, we sought to characterize plasma mcfDNA in order to explore its potential association with the immunologic complications of transplantation. We compared serially collected patient samples with plasma collected from healthy control subjects.

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Background: Patients without human immunodeficiency virus (HIV) are increasingly recognized as being at risk for cryptococcosis. Knowledge of characteristics of cryptococcosis in these patients remains incomplete.

Methods: We conducted a retrospective study of cryptococcosis in 46 Australian and New Zealand hospitals to compare its frequency in patients with and without HIV and describe its characteristics in patients without HIV.

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Pregnancy poses a greater risk for severe COVID-19; however, underlying immunological changes associated with SARS-CoV-2 during pregnancy are poorly understood. We defined immune responses to SARS-CoV-2 in unvaccinated pregnant and nonpregnant women with acute and convalescent COVID-19, quantifying 217 immunological parameters. Humoral responses to SARS-CoV-2 were similar in pregnant and nonpregnant women, although our systems serology approach revealed distinct antibody and FcγR profiles between pregnant and nonpregnant women.

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Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection causes severe coronavirus disease 2019 (COVID-19) in a small proportion of infected individuals. The immune system plays an important role in the defense against SARS-CoV-2, but our understanding of the cellular immune parameters that contribute to severe COVID-19 disease is incomplete. Here, we show that populations of effector γδ T cells are associated with COVID-19 in unvaccinated patients with acute disease.

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Respiratory tract infection with SARS-CoV-2 results in varying immunopathology underlying COVID-19. We examine cellular, humoral and cytokine responses covering 382 immune components in longitudinal blood and respiratory samples from hospitalized COVID-19 patients. SARS-CoV-2-specific IgM, IgG, IgA are detected in respiratory tract and blood, however, receptor-binding domain (RBD)-specific IgM and IgG seroconversion is enhanced in respiratory specimens.

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Invasive aspergillosis (IA) in haematology/oncology patients presents as primary infection or breakthrough infection, which can become refractory to antifungal treatment and has a high associated mortality. Other emerging patient risk groups include patients in the intensive care setting with severe respiratory viral infections, including COVID-19. These guidelines present key diagnostic and treatment recommendations in light of advances in knowledge since the previous guidelines in 2014.

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We describe severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-specific immune responses in a patient with lymphoma and recent programmed death 1 (PD-1) inhibitor therapy with late onset of severe coronavirus disease 2019 disease and prolonged SARS-CoV-2 replication, in comparison to age-matched and immunocompromised controls. High levels of HLA-DR/CD38 activation, interleukin 6, and interleukin 18 in the absence of B cells and PD-1 expression was observed. SARS-CoV-2-specific antibody responses were absent and SARS-CoV-2-specific T cells were minimally detected.

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Background: Countries with a high prevalence of COVID-19 have identified a reduction in crude hospital admission rates for non-COVID-19 conditions during the pandemic. There remains a paucity of such data from lower prevalence countries, including Australia.

Aims: To describe the patterns of unplanned hospital daily admission rates during the COVID-19 pandemic in a major Australian metropolitan hospital, with a focus on acute medical presentations including acute coronary syndrome (ACS), stroke and falls.

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Malakoplakia is a chronic granulomatous disease associated with incomplete clearance of bacterial pathogens. A multimodal approach to therapy includes antimicrobials with intracellular activity, reduction in immunosuppression, and debulking of lesions. Azithromycin has an intracellular mechanism of action and enhanced Gram-negative activity compared to other macrolides.

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To better understand primary and recall T cell responses during coronavirus disease 2019 (COVID-19), it is important to examine unmanipulated severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-specific T cells. By using peptide-human leukocyte antigen (HLA) tetramers for direct ex vivo analysis, we characterized CD8 T cells specific for SARS-CoV-2 epitopes in COVID-19 patients and unexposed individuals. Unlike CD8 T cells directed toward subdominant epitopes (B7/N, A2/S, and A24/S) CD8 T cells specific for the immunodominant B7/N epitope were detected at high frequencies in pre-pandemic samples and at increased frequencies during acute COVID-19 and convalescence.

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Background: The association of pro-inflammatory markers such as interleukin-6 (IL-6) and other biomarkers with severe coronavirus disease 2019 (COVID-19) is of increasing interest, however their kinetics, response to current COVID-related treatments, association with disease severity and comparison with other disease states associated with potential cytokine storm (CS) such as Staphylococcus aureus bacteraemia (SAB) are ill-defined.

Methods: A cohort of 55 hospitalized SARS-CoV-2 positive patients was prospectively recruited - blood sampling was performed at baseline, post-treatment and hospital discharge. Serum IL-6, C-reactive protein (CRP) and other laboratory investigations were compared between treatment groups and across timepoints.

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SARS-CoV-2 causes a spectrum of COVID-19 disease, the immunological basis of which remains ill defined. We analyzed 85 SARS-CoV-2-infected individuals at acute and/or convalescent time points, up to 102 days after symptom onset, quantifying 184 immunological parameters. Acute COVID-19 presented with high levels of IL-6, IL-18, and IL-10 and broad activation marked by the upregulation of CD38 on innate and adaptive lymphocytes and myeloid cells.

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Objectives: We report on the key clinical predictors of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and present a clinical decision rule that can risk stratify patients for COVID-19.

Design, Participants And Setting: A prospective cohort of patients assessed for COVID-19 at a screening clinic in Melbourne, Australia. The primary outcome was a positive COVID-19 test from nasopharyngeal swab.

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Cytomegalovirus (CMV) is a significant cause of morbidity and mortality in the immunocompromised host. Atypical presentations which include pseudotumors or "cancer mimics" have been described. The etiology of these lesions remains unclear.

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Purpose Of Review: The gut microbiome presents a novel source of diagnostic and therapeutic potential to modify post allogeneic stem cell transplant complications. There is an explosion of interest in microbiome research, mostly in the form of single-centre prospective time-series cohorts utilizing a variety of sampling frequencies and metagenomic technologies to sequence the microbiome. The purpose of this review is to summarize important recent publications and contextualize them within what has already been described in this rapidly growing field.

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