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Ratiu C, Dufresne SF, Thiant S, Roy J. Epstein-Barr Virus Monitoring after an Allogeneic Hematopoietic Stem Cell Transplant: Review of the Recent Data and Current Practices in Canada. Curr Oncol 2024; 31:2780-2795. [PMID: 38785492 PMCID: PMC11119229 DOI: 10.3390/curroncol31050211] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2024] [Revised: 05/10/2024] [Accepted: 05/10/2024] [Indexed: 05/25/2024] Open
Abstract
Epstein-Barr virus-related post-transplantation lymphoproliferative disorder (EBV-PTLD) is a serious complication following hematopoietic stem cell transplantation (HSCT). A pre-emptive strategy using rituximab, which aims to manage patients early at the time of EBV reactivation to avoid PTLD, has been recommended by the most recent ECIL-6 guidelines in 2016. However, there is still a great heterogeneity of viral-load monitoring protocols, targeted patient populations, and pre-emptive treatment characteristics between centers, making precise EBV monitoring recommendations difficult. We conducted a literature review from the most recent publications between 1 January 2015 and 1 August 2023, to summarize the emerging data on EBV-PTLD prevention strategies in HSCT recipients, including the EBV-DNA threshold and use of rituximab. We also present the results of a survey of current practices carried out in 12 of the main HSCT centers across Canada. We confirm that pre-emptive rituximab remains an efficient strategy for EBV-PTLD prevention. However, there is an urgent need to perform prospective, randomized, multicentric trials with larger numbers of patients reflecting current practices to determine the best clinical conduct with regards to rituximab dosing, timing of treatment, and criteria to initiate treatments. Longer follow-ups will also be necessary to assess patients' long-term outcomes.
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Affiliation(s)
- Claire Ratiu
- Faculty of Medicine, Université de Montréal, Montréal, QC H3T 1J4, Canada
| | - Simon F. Dufresne
- Department of Microbiology, Infectious Diseases and Immunology, Faculty of Medicine, Université de Montréal, Montréal, QC H3T 1J4, Canada
- Division of Infectious Diseases and Clinical Microbiology, Department of Medicine, Maisonneuve-Rosemont Hospital, Montréal, QC H1T 2M4, Canada
- Centre de Recherche de l’Hôpital Maisonneuve-Rosemont, Montréal, QC H1T 2M4, Canada
| | - Stéphanie Thiant
- Centre de Recherche de l’Hôpital Maisonneuve-Rosemont, Montréal, QC H1T 2M4, Canada
- Division of Hematology, Oncology and Transplantation, Department of Medicine, Maisonneuve-Rosemont Hospital, 5415 de l’Assomption, Montréal, QC H1T 2M4, Canada
| | - Jean Roy
- Faculty of Medicine, Université de Montréal, Montréal, QC H3T 1J4, Canada
- Centre de Recherche de l’Hôpital Maisonneuve-Rosemont, Montréal, QC H1T 2M4, Canada
- Division of Hematology, Oncology and Transplantation, Department of Medicine, Maisonneuve-Rosemont Hospital, 5415 de l’Assomption, Montréal, QC H1T 2M4, Canada
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Taeschler P, Adamo S, Deng Y, Cervia C, Zurbuchen Y, Chevrier S, Raeber ME, Hasler S, Bächli E, Rudiger A, Stüssi‐Helbling M, Huber LC, Bodenmiller B, Boyman O, Nilsson J. T-cell recovery and evidence of persistent immune activation 12 months after severe COVID-19. Allergy 2022; 77:2468-2481. [PMID: 35567391 PMCID: PMC9347640 DOI: 10.1111/all.15372] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2022] [Revised: 04/06/2022] [Accepted: 04/19/2022] [Indexed: 01/08/2023]
Abstract
BACKGROUND T-cell lymphopenia and functional impairment is a hallmark of severe acute coronavirus disease 2019 (COVID-19). How T-cell numbers and function evolve at later timepoints after clinical recovery remains poorly investigated. METHODS We prospectively enrolled and longitudinally sampled 173 individuals with asymptomatic to critical COVID-19 and analyzed phenotypic and functional characteristics of T cells using flow cytometry, 40-parameter mass cytometry, targeted proteomics, and functional assays. RESULTS The extensive T-cell lymphopenia observed particularly in patients with severe COVID-19 during acute infection had recovered 6 months after infection, which was accompanied by a normalization of functional T-cell responses to common viral antigens. We detected persisting CD4+ and CD8+ T-cell activation up to 12 months after infection, in patients with mild and severe COVID-19, as measured by increased HLA-DR and CD38 expression on these cells. Persistent T-cell activation after COVID-19 was independent of administration of a COVID-19 vaccine post-infection. Furthermore, we identified a subgroup of patients with severe COVID-19 that presented with persistently low CD8+ T-cell counts at follow-up and exhibited a distinct phenotype during acute infection consisting of a dysfunctional T-cell response and signs of excessive pro-inflammatory cytokine production. CONCLUSION Our study suggests that T-cell numbers and function recover in most patients after COVID-19. However, we find evidence of persistent T-cell activation up to 12 months after infection and describe a subgroup of severe COVID-19 patients with persistently low CD8+ T-cell counts exhibiting a dysregulated immune response during acute infection.
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Affiliation(s)
- Patrick Taeschler
- Department of Immunology University Hospital Zurich (USZ) Zurich Switzerland
| | - Sarah Adamo
- Department of Immunology University Hospital Zurich (USZ) Zurich Switzerland
| | - Yun Deng
- Department of Immunology University Hospital Zurich (USZ) Zurich Switzerland
| | - Carlo Cervia
- Department of Immunology University Hospital Zurich (USZ) Zurich Switzerland
| | - Yves Zurbuchen
- Department of Immunology University Hospital Zurich (USZ) Zurich Switzerland
| | - Stéphane Chevrier
- Department of Quantitative Biomedicine University of Zurich Zurich Switzerland
- Institute of Molecular Health Sciences ETH Zurich Zurich Switzerland
| | - Miro E. Raeber
- Department of Immunology University Hospital Zurich (USZ) Zurich Switzerland
| | - Sara Hasler
- Department of Immunology University Hospital Zurich (USZ) Zurich Switzerland
| | - Esther Bächli
- Clinic for Internal Medicine, Hirslanden Klinik St. Anna Lucerne Switzerland
| | - Alain Rudiger
- Department of Medicine Limmattal Hospital Schlieren Switzerland
| | | | - Lars C. Huber
- Clinic for Internal Medicine, City Hospital Triemli Zurich Zurich Switzerland
| | - Bernd Bodenmiller
- Department of Quantitative Biomedicine University of Zurich Zurich Switzerland
- Institute of Molecular Health Sciences ETH Zurich Zurich Switzerland
| | - Onur Boyman
- Department of Immunology University Hospital Zurich (USZ) Zurich Switzerland
- Faculty of Medicine University of Zurich Zurich Switzerland
| | - Jakob Nilsson
- Department of Immunology University Hospital Zurich (USZ) Zurich Switzerland
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Adamo S, Chevrier S, Cervia C, Zurbuchen Y, Raeber ME, Yang L, Sivapatham S, Jacobs A, Baechli E, Rudiger A, Stüssi‐Helbling M, Huber LC, Schaer DJ, Bodenmiller B, Boyman O, Nilsson J. Profound dysregulation of T cell homeostasis and function in patients with severe COVID-19. Allergy 2021; 76:2866-2881. [PMID: 33884644 PMCID: PMC8251365 DOI: 10.1111/all.14866] [Citation(s) in RCA: 36] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2020] [Revised: 03/09/2021] [Accepted: 03/14/2021] [Indexed: 01/08/2023]
Abstract
Background Coronavirus disease 2019 (COVID‐19) is caused by infection with severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) and shows a broad clinical presentation ranging from asymptomatic infection to fatal disease. A very prominent feature associated with severe COVID‐19 is T cell lymphopenia. However, homeostatic and functional properties of T cells are ill‐defined in COVID‐19. Methods We prospectively enrolled individuals with mild and severe COVID‐19 into our multicenter cohort and performed a cross‐sectional analysis of phenotypic and functional characteristics of T cells using 40‐parameter mass cytometry, flow cytometry, targeted proteomics, and functional assays. Results Compared with mild disease, we observed strong perturbations of peripheral T cell homeostasis and function in severe COVID‐19. Individuals with severe COVID‐19 showed T cell lymphopenia and redistribution of T cell populations, including loss of naïve T cells, skewing toward CD4+T follicular helper cells and cytotoxic CD4+ T cells, and expansion of activated and exhausted T cells. Extensive T cell apoptosis was particularly evident with severe disease and T cell lymphopenia, which in turn was accompanied by impaired T cell responses to several common viral antigens. Patients with severe disease showed elevated interleukin‐7 and increased T cell proliferation. Furthermore, patients sampled at late time points after symptom onset had higher T cell counts and improved antiviral T cell responses. Conclusion Our study suggests that severe COVID‐19 is characterized by extensive T cell dysfunction and T cell apoptosis, which is associated with signs of homeostatic T cell proliferation and T cell recovery.
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Affiliation(s)
- Sarah Adamo
- Department of Immunology University Hospital Zurich (USZ) Zurich Switzerland
| | - Stéphane Chevrier
- Department of Quantitative Biomedicine University of Zurich Zurich Switzerland
- Institute of Molecular Health Sciences ETH Zurich Zurich Switzerland
| | - Carlo Cervia
- Department of Immunology University Hospital Zurich (USZ) Zurich Switzerland
| | - Yves Zurbuchen
- Department of Immunology University Hospital Zurich (USZ) Zurich Switzerland
| | - Miro E. Raeber
- Department of Immunology University Hospital Zurich (USZ) Zurich Switzerland
| | - Liliane Yang
- Department of Immunology University Hospital Zurich (USZ) Zurich Switzerland
| | - Sujana Sivapatham
- Department of Quantitative Biomedicine University of Zurich Zurich Switzerland
- Institute of Molecular Health Sciences ETH Zurich Zurich Switzerland
| | - Andrea Jacobs
- Department of Quantitative Biomedicine University of Zurich Zurich Switzerland
- Institute of Molecular Health Sciences ETH Zurich Zurich Switzerland
| | - Esther Baechli
- Clinic for Internal Medicine Uster Hospital Uster Switzerland
| | - Alain Rudiger
- Department of Medicine Limmattal Hospital Schlieren Switzerland
| | | | - Lars C. Huber
- Clinic for Internal Medicine City Hospital Triemli Zurich Zurich Switzerland
| | | | - Bernd Bodenmiller
- Department of Quantitative Biomedicine University of Zurich Zurich Switzerland
- Institute of Molecular Health Sciences ETH Zurich Zurich Switzerland
| | - Onur Boyman
- Department of Immunology University Hospital Zurich (USZ) Zurich Switzerland
- Faculty of Medicine University of Zurich Zurich Switzerland
| | - Jakob Nilsson
- Department of Immunology University Hospital Zurich (USZ) Zurich Switzerland
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Sardiu ME, Box AC, Haug JS, Washburn MP. Identification of stem cells from large cell populations with topological scoring. Mol Omics 2020; 17:59-65. [PMID: 32924050 DOI: 10.1039/d0mo00039f] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Machine learning and topological analysis methods are becoming increasingly used on various large-scale omics datasets. Modern high dimensional flow cytometry data sets share many features with other omics datasets like genomics and proteomics. For example, genomics or proteomics datasets can be sparse and have high dimensionality, and flow cytometry datasets can also share these features. This makes flow cytometry data potentially a suitable candidate for employing machine learning and topological scoring strategies, for example, to gain novel insights into patterns within the data. We have previously developed a Topological Score (TopS) and implemented it for the analysis of quantitative protein interaction network datasets. Here we show that TopS approach for large scale data analysis is applicable to the analysis of a previously described flow cytometry sorted human hematopoietic stem cell dataset. We demonstrate that TopS is capable of effectively sorting this dataset into cell populations and identify rare cell populations. We demonstrate the utility of TopS when coupled with multiple approaches including topological data analysis, X-shift clustering, and t-Distributed Stochastic Neighbor Embedding (t-SNE). Our results suggest that TopS could be effectively used to analyze large scale flow cytometry datasets to find rare cell populations.
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Affiliation(s)
- Mihaela E Sardiu
- Stowers Institute for Medical Research, 1000 E. 50th St, Kansas City, MO 64110, USA.
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Impact of γδ T cells on clinical outcome of hematopoietic stem cell transplantation: systematic review and meta-analysis. Blood Adv 2020; 3:3436-3448. [PMID: 31714966 DOI: 10.1182/bloodadvances.2019000682] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2019] [Accepted: 09/30/2019] [Indexed: 12/19/2022] Open
Abstract
Allogeneic hematopoietic stem cell transplantation (HSCT) using αβ T-/B-cell-depleted grafts recently emerged as a transplant strategy and highlighted the potential role of γδ T cells on HSCT outcomes. Our aim was to scrutinize available evidence of γδ T-cell impact on relapse, infections, survival, and acute graft-versus-host disease (aGVHD). We performed a systematic review and meta-analysis of studies assessing γδ T cells in HSCT. We searched PubMed, Web of Science, Scopus, and conference abstracts from inception to March 2019 for relevant studies. We included all studies that assessed γδ T cells associated with HSCT. Data were extracted independently by 2 investigators based on strict selection criteria. A random-effects model was used to pool outcomes across studies. Primary outcome was disease relapse. We also assessed infections, survival, and aGVHD incidence. The review was registered with PROSPERO (CRD42019133344). Our search returned 2412 studies, of which 11 (919 patients) were eligible for meta-analysis. Median follow-up was 30 months (interquartile range, 22-32). High γδ T-cell values after HSCT were associated with less disease relapse (risk ratio [RR], 0.58; 95% confidence interval [95% CI], 0.40-0.84; P = .004; I2 = 0%), fewer viral infections (RR, 0.59; 95% CI, 0.43-0.82; P = .002; I2 = 0%) and higher overall (HR, 0.28; 95% CI, 0.18-0.44; P < .00001; I2 = 0%) and disease-free survivals (HR 0.29; 95% CI, 0.18-0.48; P < .00001; I2 = 0%). We found no association between high γδ T-cell values and aGVHD incidence (RR, 0.72; 95% CI, 0.41-1.27; P = .26; I2 = 0%). In conclusion, high γδ T cells after HSCT is associated with a favorable clinical outcome but not with aGVHD development, suggesting that γδ T cells have a significant effect on the success of HSCT. This study was registered with PROSPERO as #CRD42019133344.
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de Silva HD, Ffrench RA, Korem M, Orlowski E, Curtis DJ, Spencer A, Avery S, Patil S, Morrissey CO. Contemporary analysis of functional immune recovery to opportunistic and vaccine-preventable infections after allogeneic haemopoietic stem cell transplantation. Clin Transl Immunology 2018; 7:e1040. [PMID: 30323928 PMCID: PMC6173278 DOI: 10.1002/cti2.1040] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2018] [Revised: 09/02/2018] [Accepted: 09/03/2018] [Indexed: 01/23/2023] Open
Abstract
Objectives Infections are a major cause of mortality after allogeneic haemopoietic stem cell transplantation (alloHSCT), and immune recovery is necessary for prevention. Novel transplant procedures have changed the epidemiology of infections but contemporary data on functional immune recovery are limited. In this pilot study, we aimed to measure immune recovery in the current era of alloHSCT. Methods Twenty, 13, 11, 9 and 9 alloHSCT recipients had blood collected at baseline (time of conditioning) and 3‐, 6‐, 9‐, and 12‐months post‐alloHSCT, respectively. Clinical data were collected, and immune recovery was measured using immunophenotyping, lymphocyte proliferation, cytokine analysis and antibody isotyping. Results Median absolute T‐ and B‐cell counts were below normal from baseline until 9‐ to 12‐months post‐alloHSCT. Median absolute CD4+ T‐cell counts recovered at 12‐months post‐alloHSCT. Positive proliferative responses to Aspergillus, cytomegalovirus (CMV), Epstein‐Barr virus (EBV), influenza and tetanus antigens were detected from 9 months. IL‐6 was the most abundant cytokine in cell cultures. In cultures stimulated with CMV, EBV, influenza and tetanus peptides, the CD4+ T‐cell count correlated with IL‐1β (P = 0.045) and CD8+ T‐cell count with IFNγ (P = 0.013) and IL‐1β (P = 0.012). The NK‐cell count correlated with IL‐1β (P = 0.02) and IL‐17a (P = 0.03). Median serum levels of IgG1, IgG2 and IgG3 were normal while IgG4 and IgA were below normal range throughout follow‐up. Conclusions This pilot study demonstrates that immune recovery can be measured using CD4+ T‐cell counts, in vitro antigen stimulation and selected cytokines (IFNγ, IL‐1β, IL‐4, IL‐6, IL‐17, IL‐21, IL‐31) in alloHSCT recipients. While larger studies are required, monitoring immune recovery may have utility in predicting infection risk post‐alloHSCT.
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Affiliation(s)
- Harini D de Silva
- Burnet Institute Life Sciences Discipline Melbourne VIC Australia.,Department of Infectious Diseases Alfred Health and Monash University Melbourne VIC Australia.,Present address: Peter MacCallum Cancer Centre Melbourne VIC Australia
| | - Rosemary A Ffrench
- Burnet Institute Life Sciences Discipline Melbourne VIC Australia.,Department of Immunology Central Clinical School Monash University Melbourne VIC Australia
| | - Maya Korem
- Department of Infectious Diseases Alfred Health and Monash University Melbourne VIC Australia.,Present address: Hadassah University Medical Centre Jerusalem Israel
| | - Eva Orlowski
- Burnet Institute Life Sciences Discipline Melbourne VIC Australia
| | - David J Curtis
- Australian Centre for Blood Diseases Monash University Melbourne VIC Australia.,Malignant Haematology and Stem Cell Transplantation Service Alfred Health Melbourne VIC Australia
| | - Andrew Spencer
- Australian Centre for Blood Diseases Monash University Melbourne VIC Australia.,Malignant Haematology and Stem Cell Transplantation Service Alfred Health Melbourne VIC Australia
| | - Sharon Avery
- Malignant Haematology and Stem Cell Transplantation Service Alfred Health Melbourne VIC Australia
| | - Sushrut Patil
- Malignant Haematology and Stem Cell Transplantation Service Alfred Health Melbourne VIC Australia
| | - Catherine Orla Morrissey
- Department of Infectious Diseases Alfred Health and Monash University Melbourne VIC Australia.,Malignant Haematology and Stem Cell Transplantation Service Alfred Health Melbourne VIC Australia
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Yong MK, Cameron PU, Slavin MA, Cheng AC, Morrissey CO, Bergin K, Spencer A, Ritchie D, Lewin SR. Low T-Cell Responses to Mitogen Stimulation Predicts Poor Survival in Recipients of Allogeneic Hematopoietic Stem Cell Transplantation. Front Immunol 2017; 8:1506. [PMID: 29170666 PMCID: PMC5684122 DOI: 10.3389/fimmu.2017.01506] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2017] [Accepted: 10/25/2017] [Indexed: 12/17/2022] Open
Abstract
Background Successful engraftment and reconstitution of the innate and adaptive immune system are associated with improved outcomes in recipients of allogeneic hematopoietic stem cell transplantation (HSCT). A clinically meaningful and simple biomarker of immunosuppression could potentially assist clinicians in their decision-making. We aimed to determine the relationship between T-cell production of interferon gamma (IFN-γ) in response to phytohemagglutinin (PHA) to clinical outcomes in HSCT recipients. Methods A prospective observational multicenter study of 73 adult allogeneic HSCT recipients was conducted in Melbourne, Australia. Eligible participants were >18 years and at risk of cytomegalovirus disease. T-cell responses to PHA were assessed at 3, 6, 9, and 12 months post-HSCT using the commercial quantiferon-cytomegalovirus assay, which quantifies IFN-γ production by ELISA following stimulation with PHA. A low response was defined as IFN-γ <0.5 IU/ml following stimulation with PHA. Results At 3 months post-HSCT, high responses to PHA (median IFN-γ 7.68 IU/ml) were seen in 63% of participants and low responses to PHA (median IFN-γ 0.06 IU/ml) in 37%. IFN-γ responses to PHA were significantly associated with the severity of acute graft versus host disease (AGVHD) (spearman r = −0.53, p < 0.001) and correlated with blood lymphocyte count (spearman r = 0.52, p < 0.001). Twelve month overall survival was greater in individuals with high compared to low IFN-γ response to PHA at 3 months [92 vs. 62%, respectively, Cox proportional hazard ratio (HR): 4.12 95% CI: 1.2–13.7, p = 0.02]. Non-relapse mortality (NRM) was higher in individuals with low IFN-γ response to PHA (competing risk regression HR 11.6 p = 0.02). In individuals with no AGVHD compared to AGVHD and high IFN-γ response to PHA compared to AGVHD and low IFN-γ response to PHA, 12-month survival was 100 vs. 80 vs. 52%, respectively (log rank test p < 0.0001). Conclusion Low IFN-γ response to PHA at the 3-month time-point following allogeneic HSCT was predictive of reduced 12-month overall survival, increased NRM, and reduced survival in recipients with AGVHD. Assessing IFN-γ response to PHA post-HSCT may be a clinically useful immune biomarker.
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Affiliation(s)
- Michelle K Yong
- Department of Infectious Diseases, Monash University and Alfred Hospital, Melbourne, VIC, Australia.,The Peter Doherty Institute for Infection and Immunity, The University of Melbourne and Royal Melbourne Hospital, Melbourne, VIC, Australia.,National Centre for Infections in Cancer, Peter MacCallum Cancer Centre, Melbourne, VIC, Australia
| | - Paul U Cameron
- Department of Infectious Diseases, Monash University and Alfred Hospital, Melbourne, VIC, Australia.,The Peter Doherty Institute for Infection and Immunity, The University of Melbourne and Royal Melbourne Hospital, Melbourne, VIC, Australia
| | - Monica A Slavin
- The Peter Doherty Institute for Infection and Immunity, The University of Melbourne and Royal Melbourne Hospital, Melbourne, VIC, Australia.,National Centre for Infections in Cancer, Peter MacCallum Cancer Centre, Melbourne, VIC, Australia.,Victorian Infectious Diseases Service, Royal Melbourne Hospital at The Peter Doherty Institute for Infection and Immunity, Melbourne, VIC, Australia
| | - Allen C Cheng
- Department of Infectious Diseases, Monash University and Alfred Hospital, Melbourne, VIC, Australia
| | - C Orla Morrissey
- Department of Infectious Diseases, Monash University and Alfred Hospital, Melbourne, VIC, Australia.,Department of Haematology, Monash University and Alfred Hospital, Melbourne, VIC, Australia
| | - Krystal Bergin
- Department of Haematology, Monash University and Alfred Hospital, Melbourne, VIC, Australia
| | - Andrew Spencer
- Department of Haematology, Monash University and Alfred Hospital, Melbourne, VIC, Australia
| | - David Ritchie
- Department of Clinical Haematology and Bone Marrow Transplant Service, The Royal Melbourne Hospital, Melbourne, VIC, Australia.,Department of Medicine, University of Melbourne, Melbourne, VIC, Australia
| | - Sharon R Lewin
- Department of Infectious Diseases, Monash University and Alfred Hospital, Melbourne, VIC, Australia.,The Peter Doherty Institute for Infection and Immunity, The University of Melbourne and Royal Melbourne Hospital, Melbourne, VIC, Australia
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