American Society of Transplantation and Cellular Therapy Series, 2: Management and Prevention of Aspergillosis in Hematopoietic Cell Transplantation Recipients

Invasive fungal infections are rare in pediatric and young adult autologous hematopoietic stem cell transplant patients

BACKGROUND

Pediatric and young adult patients undergoing autologous hematopoietic stem cell transplant (auto-HSCT) face a crucial, yet understudied, risk of invasive fungal infections (IFI), especially compared to allogeneic transplants. This gap underscores the need for research in pediatric patients undergoing auto-HSCT. Our objective was to evaluate the incidence of IFI in pediatric and young adult patients during the first year after auto-HSCT.

MATERIALS AND METHODS

We conducted a single-center retrospective analysis of 150 pediatric and young adult auto-HSCT patients who underwent transplant from January 2013 to January 2023. We focused on IFI incidence within the first-year post transplant, using the European Organization for Research and Treatment of Cancer/Mycoses Study Group (EORTC/MSG) criteria for IFI identification.

RESULTS

Among the 150 patients analyzed, with 240 unique transplant episodes, the primary indication was neuroblastoma (37.3%), and micafungin was extensively used for prophylaxis (82.7%). There was an absence of IFI from yeast and mold species, suggesting a low IFI risk in this cohort. The incidence of IFI in pediatric auto-HSCT recipients receiving micafungin primary antifungal prophylaxis is rare.

CONCLUSIONS

The findings advocate for further research to refine prophylaxis guidelines and highlight the need for individualized risk assessment to optimize post-transplant care.

Diagnostic limitations and challenges in current clinical guidelines and potential application of metagenomic sequencing to manage pulmonary invasive fungal infections in patients with haematological malignancies

BACKGROUND

Pulmonary invasive fungal infections (pIFI) disproportionately affect patients with haematological malignancies (HM). Establishing a rapid and accurate diagnosis of pIFI is challenging. Multiple guidelines recommend diagnostic testing of invasive fungal infections but lack consensus and may contribute to inconsistent diagnostic approaches.

OBJECTIVE

To identify key diagnostic challenges and review metagenomic sequencing data.

SOURCES

PubMed, professional consortium, and scientific society websites search to identify relevant, published, evidence-based clinical guidelines within the past 5 years. PubMed searchs for papers describing clinically relevant novel diagnostic technologies.

CONTENT

Current guidelines for patients with HM and suspected pIFI recommend chest computed tomography imaging and specimen testing with microscopic examination (including calcofluor white stain, histopathology, cytopathology, etc.), Aspergillus galactomannan, β-D-glucan, PCR, and culture, each with certain limitations. Emerging real-world data support the adjunctive use of metagenomic sequencing-based tests for the timely diagnosis of pIFI.

IMPLICATIONS

High-quality evidence from robust clinical trials is needed to determine whether guidelines should be updated to include novel diagnostic technologies. Trials should ask whether the combination of powerful novel diagnostics, such as pathogen-agnostic metagenomic sequencing technologies in conjunction with conventional testing can optimize the diagnostic yield for all potential pIFI pathogens that impact the health of patients with HM.

An update on pharmacotherapy for fungal infections in allogeneic stem cell transplant recipients

INTRODUCTION

Invasive fungal diseases (IFD) constitute a major cause of morbidity and mortality in hematopoietic stem cell transplantation (HSCT) recipients.

AREAS COVERED

We describe epidemiology, causes and risk factors of IFD in allogeneic HSCT discussing prophylaxis and treatment in various HSCT phases. We present the most recent studies on this thematic area, including novel data on currently available antifungals, i.e. formulations, dosing, safety, efficacy and therapeutic drug monitoring. Finally, we present the most recent relevant recommendations published. Literature search included PubMed, Scopus, and clinicaltrials.gov between January 2014 and April 2024.

EXPERT OPINION

The antifungal agents employed for prophylaxis and therapy should be predicated on local epidemiology of IFD. Fluconazole prophylaxis remains a first-line choice before engraftment when the main pathogen is Candida spp. After engraftment, prophylaxis should be with mold-active agents (i.e. triazoles). For candidiasis, echinocandins are suggested as first-line treatment, whereas aspergillosis responds well to mold-active azoles and liposomal amphotericin B (L-AmB). For mucormycosis, treatment of choice includes L-AmB and isavuconazole. Choice between fever-driven and diagnostics-driven strategies remains equivocal. Open research topics remain: 1) optimization of tools to ensure prompt and accurate IFD diagnosis to avoid unnecessary exposure to antifungals, drug interactions and cost; 2) refinement of treatment for resistant/refractory strains.

Impact of Antifungal Prophylaxis Continuation or Discontinuation After Allogeneic Hematopoietic Cell Transplant on the Incidence of Invasive Mold Infection

Background

Continuing antifungal prophylaxis (AFPx) to prevent invasive mold infections (IMIs) in recipients of allogeneic hematopoietic cell transplantation (alloHCT) after primary hospital discharge from alloHCT admission varies among transplant centers despite recommendations to continue prophylaxis through day +75. Characteristics driving AFPx prescribing at hospital discharge and outcomes are unknown.

Methods

In this retrospective analysis, we reviewed patients continuing AFPx vs no AFPx at hospital discharge. We included patients with a hospital stay ≥7 days and ≤40 days. We excluded patients with a history of IMI prior to alloHCT, new IMI during admission, or death prior to discharge. Our primary objective was incidence of probable or proven IMI per the European Organization for Research and Treatment of Cancer and the Mycoses Study Group Education and Research Consortium. Our secondary objectives were nonrelapse mortality at day +100, overall survival at day +100, and characteristics driving AFPx discontinuation at hospital discharge.

Results

Of the 430 patients identified, 387 met inclusion criteria. At discharge, 56% (217/387) continued AFPx, and 44% (170/387) had no AFPx. At day +100, 3 probable IMI cases occurred in the group with continued AFPx vs 1 probable IMI case in the no-AFPx group (no proven IMI). Univariate analysis showed no difference in cumulative incidence of probable IMI (P = .440), nonrelapse mortality (P = .072), and overall survival (P = .855) between groups. Multivariable logistic regression demonstrated that patients were less likely to continue AFPx if they had a diagnosis other than acute myeloid leukemia, a length of stay ≤30 days, acute graft-vs-host disease grade 0 or 1, and corticosteroid use ≤5 days.

Conclusions

There was no difference in probable IMI at day +100 after alloHCT based on continuing vs discontinuing AFPx at hospital discharge after alloHCT admission supporting a risk-adapted prophylaxis approach.

International recommendations for screening and preventative practices for long-term survivors of transplantation and cellular therapy: a 2023 update

As hematopoietic cell transplantation (HCT) and cellular therapy expand to new indications and international access improves, the volume of HCT performed annually continues to rise. Parallel improvements in HCT techniques and supportive care entails more patients surviving long-term, creating further emphasis on survivorship needs. Survivors are at risk for developing late complications secondary to pre-, peri- and post-transplant exposures and other underlying risk-factors. Guidelines for screening and preventive practices for HCT survivors were originally published in 2006 and updated in 2012. To review contemporary literature and update the recommendations while considering the changing practice of HCT and cellular therapy, an international group of experts was again convened. This review provides updated pediatric and adult survivorship guidelines for HCT and cellular therapy. The contributory role of chronic graft-versus-host disease (cGVHD) to the development of late effects is discussed but cGVHD management is not covered in detail. These guidelines emphasize special needs of patients with distinct underlying HCT indications or comorbidities (e.g., hemoglobinopathies, older adults) but do not replace more detailed group, disease, or condition specific guidelines. Although these recommendations should be applicable to the vast majority of HCT recipients, resource constraints may limit their implementation in some settings.

A Silent Threat Unveiled: Invasive Fungal Sinusitis in a High-Risk Hematologic Malignancy Patient

Invasive fungal sinusitis (IFS) poses a fatal threat to patients with hematological malignancies or a history of allogeneic hematopoietic stem cell transplant (HSCT). While invasive aspergillosis, a subtype of IFS, remains rare in immunocompetent individuals, allogeneic HSCT recipients face a notable surge in incidence. Despite the rapid onset and progression of IFS, its clinical presentation is subtle, contributing to heightened mortality rates. Prompt surgical debridement and systemic antifungal therapy are required to yield positive results. Examining IFS cases in HSCT recipients is vital, providing insights into its clinical course, prevention strategies, and improved evaluation. We present a rare presentation of IFS with Aspergillus niger in a relapsed acute myeloid leukemia patient post-HSCT. Two weeks after chemotherapy, the patient developed headaches and blood-tinged sinus drainage in the setting of pancytopenia. Radiologic and pathological findings confirmed the diagnosis of IFS, necessitating weeks of intensive anti-fungal therapy. Despite the initial positive response, the disease ultimately progressed to a fatal outcome. This case emphasizes that early detection is required for a favorable treatment response. Furthermore, it underscores the importance of heightened clinical suspicion, risk stratification, multidisciplinary care, and ongoing research for optimal management of IFS in allogeneic HSCT recipients.

International Recommendations for Screening and Preventative Practices for Long-Term Survivors of Transplantation and Cellular Therapy: A 2023 Update

As hematopoietic cell transplantation (HCT) and cellular therapy expand to new indications and international access improves, the number of HCTs performed annually continues to rise. Parallel improvements in HCT techniques and supportive care entails more patients surviving long term, creating further emphasis on survivorship needs. Survivors are at risk for developing late complications secondary to pretransplantation, peritransplantation, and post-transplantation exposures and other underlying risk factors. Guidelines for screening and preventive practices for HCT survivors were originally published in 2006 and then updated in 2012. An international group of experts was convened to review the contemporary literature and update the recommendations while considering the changing practices of HCT and cellular therapy. This review provides updated pediatric and adult survivorship guidelines for HCT and cellular therapy. The contributory role of chronic graft-versus-host disease (cGVHD) to the development of late effects is discussed, but cGVHD management is not covered in detail. These guidelines emphasize the special needs of patients with distinct underlying HCT indications or comorbidities (eg, hemoglobinopathies, older adults) but do not replace more detailed group-, disease-, or condition-specific guidelines. Although these recommendations should be applicable to the vast majority of HCT recipients, resource constraints may limit their implementation in some settings.

Population pharmacokinetics of posaconazole in allogeneic haematopoietic stem cell transplant patients

BACKGROUND

Invasive fungal disease (IFD) in the early post-allogeneic HSCT (alloHCT) period is associated with increased likelihood of catastrophic outcomes. The utility of oral modified release (MR) posaconazole tablets is limited by reduced drug absorption from gastrointestinal toxicity induced by cytotoxic chemotherapy, necessitating a switch to the IV posaconazole formulation.

OBJECTIVES

To describe the population pharmacokinetics of posaconazole for oral MR and IV formulations in alloHCT patients and determine dosing regimens likely to achieve therapeutic exposures.

METHODS

We performed a prospective observational pharmacokinetic study in adult patients in the early post-alloHCT period requiring a change in posaconazole formulation (oral to IV). Samples were analysed using a validated LC-MS/MS method. Population pharmacokinetic analysis and Monte Carlo simulations (n = 1000) were performed using Pmetrics for R.

RESULTS

Twenty patients aged between 21 and 70 years were included in the study. A two-compartment model, incorporating mucositis/diarrhoea to modify the bioavailability for oral administration best described the data. To achieve ≥90% PTA, simulations showed that higher than currently recommended doses of oral MR posaconazole were required for prophylaxis Cmin targets (≥0.5 and ≥0.7 mg/L), while increased doses of both formulations were required for IFD treatment PK/PD targets, with patients experiencing oral mucositis/diarrhoea unlikely to achieve these.

CONCLUSIONS

Increased doses of posaconazole should be considered for both prophylaxis and treatment of IFD to increase the proportion of alloHCT patients achieving therapeutic exposures, particularly the oral formulation in patients with mucositis and/or diarrhoea. Posaconazole therapeutic drug monitoring should be considered for all formulations in this setting.

How I approach: the transplant recipient with fever and pulmonary infiltrates

Recipients of hematopoietic stem cell transplants and solid organ transplants frequently develop pulmonary infiltrates from both infectious and non-infectious etiologies. Differentiation and further characterization of microbiologic etiologies-viral, bacterial, and fungal-can be exceedingly challenging. Pediatric patients face unique challenges as confirmatory evaluations with bronchoscopy or lung biopsy may be limited. A generalizable approach to diagnosing and managing these conditions has not been well established. This paper aims to summarize our initial clinical approach while discussing the relative evidence informing our practices. A pediatric patient with characteristic infiltrates who has undergone HSCT is presented to facilitate the discussion. Generalizable approaches to similar patients are highlighted as appropriate while highlighting considerations based on clinical course and key risk factors.

Beginners guide to protocol writing in transplant infectious diseases

Creating protocols surrounding the guidance of the prevention and treatment of infections in transplantation is an integral part of being a transplant infectious disease physician. This piece outlines the key components for success in developing a protocol, with an example protocol and protocol template available for readers. Collaborating effectively within the multi-disciplinary team to develop, implement, and assess the efficacy of a protocol is a skill that enhances the relationship with our transplantation colleagues and improves patient outcomes by standardizing the care delivered.

Updates in hematopoietic cell transplant and cellular therapies that enhance the risk for opportunistic infections

BACKGROUND

Infectious disease physicians may be asked to evaluate and manage a variety of infections in immunocompromised hosts undergoing hematopoietic cell transplant (HCT) and cellular therapies. Over the last decade, several advances in cellular therapy have occurred, with implications for the types of infectious complications that may be seen.

AIMS

The purpose of this review is to update the infectious disease physician on newer advances in HCT and cellular therapy, including haploidentical transplant, expanding indications for transplant in older individuals and children, and chimeric antigen receptor T-cells. We will review how these advances might influence infectious disease complications following HCT. We will also provide a perspective that infectious disease physicians can use to evaluate the degree of immune suppression in an individual patient to help determine the type of infections that may be encountered.

Breakthrough invasive fungal infections on isavuconazole prophylaxis in hematologic malignancy & hematopoietic stem cell transplant patients

BACKGROUND

Isavuconazole (ISA) is a newer antifungal used in patients with history of hematologic malignancies and hematopoietic transplant and cellular therapies (HM/TCT). Although it has a more favorable side-effect profile, breakthrough invasive fungal infections (bIFIs) while on ISA have been reported.

METHODS

In this single-center retrospective study evaluating HM/TCT patients who received prophylactic ISA for ≥7 days, we evaluated the incidence and potential risk factors for bIFIs.

RESULTS

We evaluated 106 patients who received prophylactic ISA. The patients were predominantly male (60.4%) with median age of 65 (range: 21-91) years. Acute myeloid leukemia (48/106, 45.3%) was the most common HM, with majority having relapsed and/or refractory disease (43/106, 40.6%) or receiving ongoing therapy (38/106, 35.8%). Nineteen patients (17.9%) developed bIFIs-nine proven [Fusarium (3), Candida (2), Mucorales plus Aspergillus (2), Mucorales (1), Colletotrichum (1)], four probable invasive pulmonary Aspergillus, and six possible infections. Twelve patients were neutropenic for a median of 28 (8-253) days prior to bIFI diagnosis. ISA levels checked within 7 days of bIFI diagnosis (median: 3.65 μg/mL) were comparable to industry-sponsored clinical trials. All-cause mortality among the bIFI cases was 47.4% (9/19).We also noted clinically significant cytomegalovirus co-infection in 5.3% (1/19). On univariate analysis, there were no significant differences in baseline comorbidities and potential risk factors between the two groups.

CONCLUSION

ISA prophylaxis was associated with a significant cumulative incidence of bIFIs. Despite the appealing side-effect and drug-interaction profile of ISA, clinicians must be vigilant about the potential risk for bIFIs.

Immune Effector Cell-Associated Hemophagocytic Lymphohistiocytosis-Like Syndrome

T cell-mediated hyperinflammatory responses, such as cytokine release syndrome (CRS) and immune effector cell-associated neurotoxicity syndrome (ICANS), are now well-established toxicities of chimeric antigen receptor (CAR) T cell therapy. As the field of CAR T cells advances, however, there is increasing recognition that hemophagocytic lymphohistiocytosis (HLH)-like toxicities following CAR T cell infusion are occurring broadly across patient populations and CAR T cell constructs. Importantly, these HLH-like toxicities are often not as directly associated with CRS and/or its severity as initially described. This emergent toxicity, however ill-defined, is associated with life-threatening complications, creating an urgent need for improved identification and optimal management. With the goal of improving patient outcomes and formulating a framework to characterize and study this HLH-like syndrome, we established an American Society for Transplantation and Cellular Therapy panel composed of experts in primary and secondary HLH, pediatric and adult HLH, infectious disease, rheumatology and hematology, oncology, and cellular therapy. Through this effort, we provide an overview of the underlying biology of classical primary and secondary HLH, explore its relationship with similar manifestations following CAR T cell infusions, and propose the term "immune effector cell-associated HLH-like syndrome (IEC-HS)" to describe this emergent toxicity. We also delineate a framework for identifying IEC-HS and put forward a grading schema that can be used to assess severity and facilitate cross-trial comparisons. Additionally, given the critical need to optimize outcomes for patients experiencing IEC-HS, we provide insight into potential treatment approaches and strategies to optimize supportive care and delineate alternate etiologies that should be considered in a patient presenting with IEC-HS. By collectively defining IEC-HS as a hyperinflammatory toxicity, we can now embark on further study of the pathophysiology underlying this toxicity profile and make strides toward a more comprehensive assessment and treatment approach.

Personalized hematopoietic stem cell transplantation for inborn errors of immunity

Patients with inborn errors of immunity (IEI) have been transplanted for more than 50 years. Many long-term survivors have ongoing medical issues showing the need for further improvements in how hematopoietic stem cell transplantation (HSCT) is performed if patients in the future are to have a normal quality of life. Precise genetic diagnosis enables early treatment before recurrent infection, autoimmunity and organ impairment occur. Newborn screening for severe combined immunodeficiency (SCID) is established in many countries. For newly described disorders the decision to transplant is not straight-forward. Specific biologic therapies are effective for some diseases and can be used as a bridge to HSCT to improve outcome. Developments in reduced toxicity conditioning and methods of T-cell depletion for mismatched donors have made transplant an option for all eligible patients. Further refinements in conditioning plus precise graft composition and additional cellular therapy are emerging as techniques to personalize the approach to HSCT for each patient.

Invasive Aspergillosis and the Impact of Azole-resistance

Purpose of Review

IA (invasive aspergillosis) caused by azole-resistant strains has been associated with higher clinical burden and mortality rates. We review the current epidemiology, diagnostic, and therapeutic strategies of this clinical entity, with a special focus on patients with hematologic malignancies.

Recent Findings

There is an increase of azole resistance in Aspergillus spp. worldwide, probably due to environmental pressure and the increase of long-term azole prophylaxis and treatment in immunocompromised patients (e.g., in hematopoietic stem cell transplant recipients). The therapeutic approaches are challenging, due to multidrug-resistant strains, drug interactions, side effects, and patient-related conditions.

Summary

Rapid recognition of resistant Aspergillus spp. strains is fundamental to initiate an appropriate antifungal regimen, above all for allogeneic hematopoietic cell transplantation recipients. Clearly, more studies are needed in order to better understand the resistance mechanisms and optimize the diagnostic methods to identify Aspergillus spp. resistance to the existing antifungal agents/classes. More data on the susceptibility profile of Aspergillus spp. against the new classes of antifungal agents may allow for better treatment options and improved clinical outcomes in the coming years. In the meantime, continuous surveillance studies to monitor the prevalence of environmental and patient prevalence of azole resistance among Aspergillus spp. is absolutely crucial.

Optimizing antifungal prophylaxis in allogeneic stem cell transplantation: A cohort study of two different approaches

BACKGROUND

Limited consensus exists on the optimal use of antifungal agents to prevent invasive fungal infection in the early post allogeneic hematopoietic stem cell transplant (alloHCT) period, particularly when patients cannot tolerate oral medication administration.

METHODS

We undertook a retrospective observational cohort study to assess the tolerability, efficacy, and cost of a new antifungal prophylaxis pathway at a major tertiary alloHCT centre. Patients aged ≥16 years who underwent alloHCT between February 2018 and October 2019 (cohort 1) or between April 2020 and November 2021 (cohort 2) were included. In both cohorts, first line prophylactic therapy was oral posaconazole. The second line drugs where oral therapy was unable to be administered were intravenous voriconazole (cohort 1) versus intravenous posaconazole (cohort 2).

RESULTS

There were 142 patients enrolled in the study, 71 in each cohort. The proportion of patients remaining on first-line prophylaxis or progressing to second-, third-, and fourth-line options was 22.5%, 39.4%, 29.6%, and 8.5% in cohort 1 and 39.4%, 59.2%, 1.4%, and 0% in cohort 2, respectively. The frequency of neuropsychiatric adverse events was significantly higher in cohort 1 compared to cohort 2 (49.3% vs. 19.8%, p = .0004). Occurrence of proven and probable fungal infections was not significantly different between cohorts. Antifungal drug expenditure was $359 935 (AUD) more in cohort 1 ($830 486 AUD) compared to cohort 2 ($477 149 AUD).

CONCLUSION

The antifungal prophylaxis pathway used in cohort 2 resulted in reduced antifungal-associated adverse effects, less patients requiring progression to 3rd and 4th line prophylaxis and reduced antifungal drug costs.

New Perspectives on Antimicrobial Agents: Isavuconazole

Isavuconazole is the newest of the clinically available advanced generation triazole antifungals and is active against a variety of yeasts, molds, and dimorphic fungi. Its current FDA-approved indications include the management of invasive aspergillosis as well as mucormycosis, though the latter indication is supported by limited clinical data. Isavuconazole did not achieve noninferiority to caspofungin for the treatment of invasive candidiasis and therefore lacks an FDA-approved indication for this invasive disease. Significant advantages of isavuconazole, primarily over voriconazole but in some circumstances posaconazole as well, make it an appealing option for the management of complex patients with invasive fungal infections. These potential advantages include lack of QTc interval prolongation, more predictable pharmacokinetics, a less complicated drug interaction profile, and improved tolerability, particularly when compared to voriconazole. This review discusses these topics in addition to addressing the in vitro activity of the compound against a variety of fungi and provides insight into other distinguishing factors among isavuconazole, voriconazole, and posaconazole. The review concludes with an opinion section in which the authors provide the reader with a framework for the current role of isavuconazole in the antifungal armamentarium and where further data are required.

Oesophageal and pulmonary invasive aspergillosis in a patient with multiple myeloma

Invasive aspergillosis (IA) is a serious fungal infection that primarily affects patients with prolonged and profound neutropenia, and compromised cell-mediated immunity. Aspergillosis of the oesophagus and gastrointestinal tract is uncommon but seen in advanced cases of disseminated IA. However, it is difficult to diagnose antemortem due to the poor specificity of the symptoms and the absence of characteristic imaging findings. Therefore, the reported cases of gastrointestinal aspergillosis have been associated with high morbidity and mortality, and frequently diagnosed postmortem. Here we present a successful outcome in a patient with relapsed and refractory multiple myeloma who had presented with febrile neutropenia, cough and dysphagia, and was diagnosed with disseminated IA comprising of pulmonary and oesophageal involvement. This case highlights the need for a high index of suspicion and the importance of invasive procedures for histopathology and molecular diagnostics to ensure an early diagnosis and therapeutic intervention.

Conventional Antifungals for Invasive Infections Delivered by Unconventional Methods; Aerosols, Irrigants, Directed Injections and Impregnated Cement

The administration of approved antifungals via unapproved formulations or administration routes (such as aerosol, direct injection, irrigation, topical formulation and antifungal-impregnated orthopedic beads or cement) may be resorted to in an attempt to optimize drug exposure while minimizing toxicities and/or drug interactions associated with conventional (systemic) administrations. Existing data regarding such administrations are mostly restricted to uncontrolled case reports of patients with diseases refractory to conventional therapies. Attribution of efficacy and tolerability is most often problematic. This review updates prior published summaries, reflecting the most recent data and its application by available prevention and treatment guidelines for invasive fungal infections. Of the various dosage forms and antifungals, perhaps none is more widely reported than the application of amphotericin B-containing aerosols for the prevention of invasive mold infections (notably Aspergillus spp.).

Introduction to the updated Australasian consensus guidelines for the management of invasive fungal disease and use of antifungal agents in the haematology/oncology setting, 2021

This article introduces the fourth update of the Australian and New Zealand consensus guidelines for the management of invasive fungal disease and use of antifungal agents in the haematology/oncology setting. These guidelines are comprised of nine articles as presented in this special issue of the Internal Medicine Journal. This introductory chapter outlines the rationale for the current update and the steps taken to ensure implementability in local settings. Given that 7 years have passed since the previous iteration of these guidelines, pertinent contextual changes that impacted guideline content and recommendations are discussed, including the evolution of invasive fungal disease (IFD) definitions. We also outline our approach to guideline development, evidence grading, review and feedback. Highlights of the 2021 update are presented, including expanded scope to provide more detailed coverage of common and emerging fungi such as Aspergillus and Candida species, and emerging fungi, and a greater focus on the principles of antifungal stewardship. We also introduce an entirely new chapter dedicated to helping healthcare workers convey important concepts related to IFD, infection prevention and antifungal therapy, to patients.

Aspergillosis: Emerging risk groups in critically ill patients

Information on invasive aspergillosis (IA) and other invasive filamentous fungal infections is limited in non-neutropenic patients admitted to the intensive care unit (ICU) and presenting with no classic IA risk factors. This review is based on the critical appraisal of relevant literature, on the authors' own experience and on discussions that took place at a consensus conference. It aims to review risk factors favoring aspergillosis in ICU patients, with a special emphasis on often overlooked or neglected conditions. In the ICU patients, corticosteroid use to treat underlying conditions such as chronic obstructive pulmonary disease (COPD), sepsis, or severe COVID-19, represents a cardinal risk factor for IA. Important additional host risk factors are COPD, decompensated cirrhosis, liver failure, and severe viral pneumonia (influenza, COVID-19). Clinical observations indicate that patients admitted to the ICU because of sepsis or acute respiratory distress syndrome are more likely to develop probable or proven IA, suggesting that sepsis could also be a possible direct risk factor for IA, as could small molecule inhibitors used in oncology. There are no recommendations for prophylaxis in ICU patients; posaconazole mold-active primary prophylaxis is used in some centers according to guidelines for other patient populations and IA treatment in critically ill patients is basically the same as in other patient populations. A combined evaluation of clinical signs and imaging, classical biomarkers such as the GM assay, and fungal cultures examination, remain the best option to assess response to treatment.

LAY SUMMARY

The use of corticosteroids and the presence of co-morbidities such as chronic obstructive pulmonary disease, acute or chronic advanced liver disease, or severe viral pneumonia caused by influenza or Covid-19, may increase the risk of invasive aspergillosis in intensive care unit patients.

Choice and duration of antifungal prophylaxis and treatment in high-risk haematology patients

PURPOSE OF REVIEW

This review aims to summarize available guidelines as well as the emerging evidence for the prevention and treatment of invasive fungal diseases in high-risk haematology patients.

RECENT FINDINGS

Primary mould-active prophylaxis is the strategy used in many centres to manage the risk of invasive fungal disease in high-risk haematology patients, and posaconazole remains the antifungal of choice for most of these patients. Data on the use of other antifungals for primary prophylaxis, including isavuconazole, are limited. There is considerable interest in identifying a strategy that would limit the use of mould-active agents to the patients who are the most likely to benefit from them. In this regard, a recent trial demonstrated that the preemptive strategy is noninferior to the empiric strategy. For primary treatment of invasive aspergillosis, two randomized trials found isavuconazole and posaconazole to be noninferior to voriconazole. Isavuconazole does not appear to require therapeutic drug monitoring.

SUMMARY

Prophylaxis and treatment of invasive fungal diseases in high-risk haematology patients is a rapidly evolving field. Critical clinical questions remain unanswered, especially regarding the management of suspected invasive fungal diseases breaking through mould-active prophylaxis, and the duration of antifungal therapy for invasive mould infections.

Infection-Related Mortality in Adults and Children Undergoing Allogeneic Hematopoietic Cell Transplantation: An Australian Registry Report

Infection-related mortality (IRM) is the most common non-relapse-related cause of death reported after allogeneic hematopoietic cell transplantation (HCT). Information on the incidence and timing of specific infective organisms and the risk factors for IRM is essential to developing prevention strategies. This report provides the first account of IRM in adults and children undergoing HCT in Australia. Between 2013 and 2018, 2705 adult and 689 pediatric first HCTs were identified from the Australasian Bone Marrow Transplant Recipient Registry database, associated with 1075 (39.7%) total overall deaths in adults and 134 (19.4%) in children. Demographics and causes of death, including infectious etiology and causative organisms, were extracted from the database for adults and children for analysis. At day +100 and 1 year post-HCT, IRM was the leading cause of early post-HCT mortality in adults, accounting for 6.2% and 9.8%, respectively; in children, IRM was the leading cause of post-HCT mortality at day +100 at 2.5% and the second highest cause of post-HCT mortality at 1 year post-HCT at 4.9%, following relapse at 5.8%. In adults, older age, transplantation not in a first complete remission (non-CR1), the use of antithymocyte globulin (ATG) or alemtuzumab, donor-positive/recipient-negative cytomegalovirus (CMV) serostatus, and acute graft-versus-host disease were significant risk factors for IRM. However, in children, age >5 years, acute lymphocytic leukemia as the primary disease, and mismatched unrelated or haploidentical donor source were predictive of IRM. Of the deaths in which an infectious etiology was reported in adults (52.4%), 49.3% were attributed to bacteria, 25.3% to fungus, 21.7% to viruses, and 3.6% to post-transplantation lymphoproliferative disorder (PTLD). The most common organisms were Pseudomonas spp, Enterococcus spp, Candida spp, Aspergillus spp, and CMV. In children where an infectious etiology was reported (64%), 13% were attributed to bacteria, 26% to fungus, 45% to viruses, and 16% to PTLD. This report highlights that IRM was the leading cause of death early post-HCT in Australia. Strategies to reduce IRM, such as individualized pre-transplantation infection risk assessment, rapid diagnostics, and prevention management strategies should be explored to determine whether these outcomes can be improved. In addition, improving the completeness and accuracy of reported data, particularly for infectious pathogens, could assist in directing management strategies to reduce IRM in HCT.