Prolonged granulocytopenia: the major risk factor for invasive pulmonary aspergillosis in patients with acute leukemia

GM-CSF-mediated epithelial-immune cell cross-talk orchestrates pulmonary immunity to Aspergillus fumigatus

Aspergillus fumigatus causes life-threatening mold pneumonia in immunocompromised patients, particularly in those with quantitative or qualitative defects in neutrophils. Whereas innate immune cell cross-talk licenses neutrophil antifungal activity in the lung, the role of epithelial cells in this process is unknown. Here, we find that surfactant protein C (SPC)-expressing lung epithelial cells integrate infection-induced interleukin-1 and type III interferon signaling to produce granulocyte-macrophage colony-stimulating factor (GM-CSF) preferentially at local sites of fungal infection and neutrophil influx. Using in vivo models that distinguish the role of GM-CSF during acute infection from its homeostatic function in alveolar macrophage survival and surfactant catabolism, we demonstrate that epithelial-derived GM-CSF increases the accumulation and fungicidal activity of GM-CSF-responsive neutrophils, which is essential for host survival. Our findings establish SPC+ epithelial cells as a central player in regulating the quality and strength of neutrophil-dependent immunity against inhaled mold pathogens.

Strategies for the prophylaxis of invasive fungal diseases in acute myeloid leukemia patients undergoing Bcl-2 inhibitor venetoclax treatment

Patients with acute myeloid leukemia (AML) are at high risk of developing invasive fungal disease (IFD) with high morbidity and attributable mortality, including those who were received Venetoclax treatment. Venetoclax, a new oral Bcl-2 inhibitor, targets tumor cells' ability to induce apoptosis. It is the only one which is approved by Food and Drug Administration (FDA) for treating newly diagnosed AML patients who are 75 years of age or older and are ineligible for intensive induction chemotherapy due to existing comorbidities. It has been shown that venetoclax-based regimens raise the risk of invasive fungal diseases (IFD) for AML patients in clinical practice. Because it can lead to prolonged and profound neutropenia in AML patients, with IFD incidence rates ranging from 5.1 % to 32 %, resulting in higher mortality rates. Because of drug-drug interactions between Venetoclax and partial antifungal agents, to choose anti-fungal prophylaxis and to adjust the dosage of agents rationally for AML patients seems crucial to physicians to those who are undergoing venetoclax-based chemotherapy. Therefore, this review aims to summary the mechanism and characteristic of IFD in AML patients and provide practical clinical suggestions and details for the prophylaxis of IFD in AML patients suffering Venetoclax-based treatment.

A practical approach to investigating nosocomial acquisition of Aspergillus

Invasive mould disease (IMD) has a high mortality in immunosuppressed patients. Invasive aspergillosis (IA) is the most common IMD. A guideline for preventing IA has been published jointly by the Centers for Disease Control and Prevention, the Infectious Disease Society of America, and the American Society of Blood and Marrow Transplantation. Use of high-efficiency particulate air filters, adequate air exchange rates, sealing of patient rooms, and preventing exposure to moulds by nursing patients in areas away from construction sites are recommended by the guideline. However, there is limited information in relation to the actions to be undertaken by infection prevention and control teams in the event of one or more cases of nosocomial aspergillosis. In this review, we describe a systematic approach to aspergillosis by defining possible and probable nosocomial acquisition based on the number of days since hospital admission. We advocate an incremental response to the investigation of nosocomial aspergillosis in patients in protective isolation taking into account the number of cases and the likelihood of nosocomial origin. For single cases of nosocomial IA, we suggest that infection control investigations should focus on case surveillance and walk-through inspection escalating in a stepwise manner to enhanced case surveillance, verification of environmental controls, environmental monitoring, genotyping of clinical and environmental isolates, and review of antifungal prophylaxis for multiple cases and outbreaks. Where applicable, the construction site should be inspected with the aim to reduce the dispersal of conidia. Surveillance systems need to be strengthened to better understand the epidemiology of IA.

An IFN-STAT1-CYBB Axis Defines Protective Plasmacytoid DC to Neutrophil Crosstalk During Aspergillus fumigatus Infection

Aspergillus fumigatus is the most common cause of invasive aspergillosis (IA), a devastating infection in immunocompromised patients. Plasmacytoid dendritic cells (pDCs) regulate host defense against IA by enhancing neutrophil antifungal properties in the lung. Here, we define the pDC activation trajectory during A. fumigatus infection and the molecular events that underlie the protective pDC - neutrophil crosstalk. Fungus-induced pDC activation begins after bone marrow egress and results in pDC-dependent regulation of lung type I and type III IFN levels. These pDC-derived products act on type I and type III IFN receptor-expressing neutrophils and control neutrophil fungicidal activity and reactive oxygen species production via STAT1 signaling in a cell-intrinsic manner. Mechanistically, neutrophil STAT1 signaling regulates the transcription and expression of Cybb, which encodes one of five NADPH oxidase subunits. Thus, pDCs regulate neutrophil-dependent immunity against inhaled molds by controlling the local expression of a subunit required for NADPH oxidase assembly and activity in the lung.

Review of the novel antifungal drug olorofim (F901318)

There is clearly a need for novel antifungal agents, not only concerning spectrum, but also oral bioavailability, tolerability, and drug-drug interactions. There is growing concern for antifungal resistance for current available antifungals, mainly driven by environmental fungicide use or long-term exposure to antifungals, in the setting of mould-active prophylaxis or for chronic antifungal infections, such as chronic pulmonary aspergillosis. Moreover, the incidence of breakthrough infections is increasing, because of the introduction of (mould-active) prophylaxis (1-4). There is emergence of difficult to treat invasive fungal infections, such as those caused by Lomentospora prolificans, cryptic species of Aspergillus, Scedosporium and Coccidioides. Olorofim (F901318) is the first-in class of the orotomides, a novel antifungal class targeting dihydroorotate dehydrogenase (DHODH), a key enzyme in the biosynthesis of pyrimidines. Olorofim shows good in vitro and in vivo activity against Aspergillus species, rare and difficult to treat moulds and endemic dimorphic fungi, including azole- and amphotericin-resistant isolates. It lacks activity against yeasts and the Mucorales species. It is only orally available and shows very promising results in ongoing clinical trials. In this review we will describe the mechanism of action of olorofim, the spectrum of activity in vitro and in vivo, pharmacokinetics, pharmacodynamics, drug-drug interactions, resistance, and clinical outcomes.

New developments in Aspergillus fumigatus and host reactive oxygen species responses

Aspergillus fumigatus is a filamentous fungus abundant in the environment and the most common causative agent of a spectrum of human diseases collectively termed aspergillosis. Invasive pulmonary aspergillosis is caused by deficiencies in innate immune function that result in the inability of the host to clear inhaled Aspergillus conidia that then germinate and form invasive hyphae. Myeloid cells, and their ability to generate reactive oxygen species (ROS), are essential for conidia clearance from the host. To combat ROS, A. fumigatus employs an expansive antioxidant system, though how these canonical antioxidant mechanisms contribute to infection initiation and disease progression remain to be fully defined. Recent research has identified noncanonical pathways in the A. fumigatus ROS response and new host populations with ROS deficiencies that are at-risk for invasive aspergillosis. Here, we highlight recent developments in the understanding of ROS at the interface of the dynamic A. fumigatus-host interaction.

Guidelines for Antibiotics Prescription in Critically Ill Patients

How to cite this article: Khilnani GC, Tiwari P, Mittal S, Kulkarni AP, Chaudhry D, Zirpe KG, et al. Guidelines for Antibiotics Prescription in Critically Ill Patients. Indian J Crit Care Med 2024;28(S2):S104-S216.

Risk factors for invasive fungal infections after haematopoietic stem cell transplantation: a systematic review and meta-analysis

BACKGROUND

Invasive fungal infections (IFIs) are common infectious complications after haematopoietic stem cell transplantation (HSCT), seriously threatening the survival of patients.

OBJECTIVES

This systematic review aimed to investigate risk factors associated with IFIs following HSCT.

METHODS

Two authors independently conducted the selection of studies and extraction of data. Risk factors for IFIs, invasive aspergillosis or invasive mould infections and invasive candida infection after HSCT were compiled separately by meta-analysis using RevMan 5.4 and R language 4.1.2.

DATA SOURCES

Pubmed, EMBASE, Web of Science, and the Cochrane Library until April 2023.

STUDY ELIGIBILITY CRITERIA

Case-control or cohort studies that assessed risk factors for IFIs among HSCT recipients were included.

PARTICIPANTS

Patients experiencing HSCT.

TEST/S

None.

REFERENCE STANDARD

The IFIs were defined according to the European Organisation for Research and Treatment of Cancer/Mycosis Study Group (EORTC/MSG) criteria, or a similar definition.

ASSESSMENT OF RISK OF BIAS

A modified version of the Newcastle-Ottawa Scale was used.

METHODS OF DATA SYNTHESIS

A random-effects model with the Mantel-Haenszel method was used to pool results from primary studies.

RESULTS

Out of 1637 studies screened, 51 studies involving 109 155 patients were included, with 45 studies providing adequate data for meta-analysis. Identified risk factors for IFIs included prolonged neutropenia, intensified therapy for graft-versus-host disease (GVHD), previous transplantation, previous proven or probable IFI, acute GVHD ≥ grade II, extensive or severe chronic GVHD, use of anti-thymocyte globulin during transplantation, haploidentical transplantation, high-dose glucocorticoids, Epstein-Barr virus infection, cytomegalovirus infection or reactivation, and lower albumin. Conversely, antifungal prophylaxis emerged as the sole preventive factor. For invasive aspergillosis or invasive mould infections, the top risk factors were extensive or severe chronic GVHD, respiratory viral infection, high-dose glucocorticoids, acute GVHD ≥ grade II, and human leukocyte antigen mismatch. Cord blood transplantation was the sole significant risk factor for invasive candidiasis. However, there was likely a high degree of interdependence among various risk factors.

DISCUSSION

This meta-analysis provides a thorough review of risk factors for IFIs infection after HSCT. The achieved insights can aid in stratifying patients who are at an elevated risk of IFIs and promoting antifungal preventive strategies.

Posaconazole versus voriconazole as antifungal prophylaxis for invasive fungal diseases in patients with hematological malignancies

INTRODUCTION

The incidence of invasive fungal diseases (IFDs) has risen in hematologic malignancy patients due to neutropenia. While posaconazole is recommended as the first-line antifungal prophylaxis in acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS) patients and voriconazole is an alternative, there is currently no direct comparison data available to assess their relative effectiveness.

METHOD

We retrospectively reviewed eligible patient charts from January 2017 to February 2019 to identify breakthrough IFD rates, drug adverse event frequency, and drug acquisition cost in AML/MDS patients.

RESULTS

Forty-eight patients received 130 chemo cycles, with 50 (38%) cycles prescribed posaconazole and 80 (62%) prescribed voriconazole as primary IFD prophylaxis. The incidence rates of IFD in the posaconazole group were 8% (4 out of 50), of which two were probable and two were possible infections, while 6.26% (5 out of 80) of patients in the voriconazole group developed IFD, with four possible infections and one probable infection (p = 0.73). A higher percentage of patients in the voriconazole group discontinued prophylaxis due to adverse events, with six patients compared to two patients in the posaconazole group (p = 0.15). The drug acquisition cost of posaconazole is 5.62 times more expensive than voriconazole.

CONCLUSION

The use of voriconazole instead of posaconazole for 130 chemo cycles would save $166,584.6. Posaconazole and voriconazole have comparable efficacy and safety in preventing IFD in AML and MDS patients receiving chemotherapy. However, posaconazole is more costly than voriconazole.

Acute Invasive Pulmonary Aspergillosis: Clinical Presentation and Treatment

Among all clinical manifestations of pulmonary aspergillosis, invasive pulmonary aspergillosis (IPA) is the most acute presentation. IPA is caused by Aspergillus hyphae invading the pulmonary tissue, causing either tracheobronchitis and/or bronchopneumonia. The degree of fungal invasion into the respiratory tissue can be seen as a spectrum, going from colonization to deep tissue penetration with angio-invasion, and largely depends on the host's immune status. Patients with prolonged, severe neutropenia and patients with graft-versus-host disease are at particularly high risk. However, IPA also occurs in other groups of immunocompromised and nonimmunocompromised patients, like solid organ transplant recipients or critically ill patients with severe viral disease. While a diagnosis of proven IPA is challenging and often warranted by safety and feasibility, physicians must rely on a combination of clinical, radiological, and mycological features to assess the likelihood for the presence of IPA. Triazoles are the first-choice regimen, and the choice of the drug should be made on an individual basis. Adjunctive therapy such as immunomodulatory treatment should also be taken into account. Despite an improving and evolving diagnostic and therapeutic armamentarium, the burden and mortality of IPA still remains high. This review aims to give a comprehensive and didactic overview of the current knowledge and best practices regarding the epidemiology, clinical presentation, diagnosis, and treatment of acute IPA.

Aspergillus and the Lung

The filamentous fungus Aspergillus causes a wide spectrum of diseases in the human lung, with Aspergillus fumigatus being the most pathogenic and allergenic subspecies. The broad range of clinical syndromes that can develop from the presence of Aspergillus in the respiratory tract is determined by the interaction between host and pathogen. In this review, an oversight of the different clinical entities of pulmonary aspergillosis is given, categorized by their main pathophysiological mechanisms. The underlying immune processes are discussed, and the main clinical, radiological, biochemical, microbiological, and histopathological findings are summarized.

Aspergillus fumigatus cytochrome c impacts conidial survival during sterilizing immunity

IMPORTANCE

Aspergillus fumigatus can cause a life-threatening infection known as invasive pulmonary aspergillosis (IPA), which is marked by fungus-attributable mortality rates of 20%-30%. Individuals at risk for IPA harbor genetic mutations or incur pharmacologic defects that impair myeloid cell numbers and/or function, exemplified by bone marrow transplant recipients, patients that receive corticosteroid therapy, or patients with chronic granulomatous disease (CGD). However, treatments for Aspergillus infections remain limited, and resistance to the few existing drug classes is emerging. Recently, the World Health Organization classified A. fumigatus as a critical priority fungal pathogen. Our cell death research identifies an important aspect of fungal biology that impacts susceptibility to leukocyte killing. Furthering our understanding of mechanisms that mediate the outcome of fungal-leukocyte interactions will increase our understanding of both the underlying fungal biology governing cell death and innate immune evasion strategies utilized during mammalian infection pathogenesis. Consequently, our studies are a critical step toward leveraging these mechanisms for novel therapeutic advances.

Aspergillus coinfection in critically Ill patients with severe dengue

In 2014-2015, a significant outbreak of dengue fever occurred in southern Taiwan, with a subsequent decline in dengue incidence. Despite this, there is emerging concern about virus-associated aspergillosis, yet limited research has explored coinfections involving dengue and aspergillosis. We conducted a retrospective study at a single center in Southern Taiwan, specifically focusing on dengue patients admitted to the intensive care unit during the period between July and November 2015. Among the 142 dengue patients studied, only 8.06 % (10/142) underwent serum galactomannan testing, with a single patient undergoing bronchoalveolar lavage (BAL) galactomannan assay. Out of those tested, 20 % (2/10) returned positive serum galactomannan results. Herein, we present two consecutive cases of coinfection involving dengue and pulmonary aspergillosis in immunocompetent patients.

Pathogenicity and virulence of Aspergillus fumigatus

Pulmonary infections caused by the mould pathogen Aspergillus fumigatus are a major cause of morbidity and mortality globally. Compromised lung defences arising from immunosuppression, chronic respiratory conditions or more recently, concomitant viral or bacterial pulmonary infections are recognised risks factors for the development of pulmonary aspergillosis. In this review, we will summarise our current knowledge of the mechanistic basis of pulmonary aspergillosis with a focus on emerging at-risk populations.

Environmental monitoring for filamentous fungal pathogens in hematopoietic cell transplant units

The incidence of invasive fungal disease (IFD) is on the rise due to increasing numbers of highly immunocompromized patients. Nosocomial IFD remains common despite our better understanding of its risk factors and pathophysiology. High-efficiency particulate air filtration with or without laminar air flow, frequent air exchanges, a positive pressure care environment, and environmental hygiene, amongst other measures, have been shown to reduce the mould burden in the patient environment. Environmental monitoring for moulds in areas where high-risk patients are cared for, such as hematopoietic cell transplant units, has been considered an adjunct to other routine environmental precautions. As a collaborative effort between authors affiliated to the Infection Prevention and Control Working Group and the Fungal Infection Working Group of the International Society of Antimicrobial Chemotherapy (ISAC), we reviewed the English language literature and international guidance to describe the evidence behind the need for environmental monitoring for filamentous fungi as a quality assurance approach with an emphasis on required additional precautions during periods of construction. Many different clinical sampling approaches have been described for air, water, and surface sampling with significant variation in laboratory methodologies between reports. Importantly, there are no agreed-upon thresholds that correlate with an increase in the clinical risk of mould infections. We highlight important areas for future research to assure a safe environment for highly immunocompromized patients.

Aspergillus fumigatus cytochrome c impacts conidial survival during sterilizing immunity

Invasive pulmonary aspergillosis (IPA) is a life-threatening infection caused by species in the ubiquitous fungal genus Aspergillus . While leukocyte-generated reactive oxygen species (ROS) are critical for the clearance of fungal conidia from the lung and resistance to IPA, the processes that govern ROS-dependent fungal cell death remain poorly defined. Using a flow cytometric approach that monitors two independent cell death markers, an endogenous histone H2A:mRFP nuclear integrity reporter and Sytox Blue cell impermeable (live/dead) stain, we observed that loss of A. fumigatus cytochrome c ( cycA ) results in reduced susceptibility to cell death from hydrogen peroxide (H 2 O 2 ) treatment. Consistent with these observations in vitro , loss of cycA confers resistance to both NADPH-oxidase -dependent and -independent killing by host leukocytes. Fungal ROS resistance is partly mediated in part by Bir1, a homolog to survivin in humans, as Bir1 overexpression results in decreased ROS-induced conidial cell death and reduced killing by innate immune cells in vivo . We further report that overexpression of the Bir1 N-terminal BIR domain in A. fumigatus conidia results in altered expression of metabolic genes that functionally converge on mitochondrial function and cytochrome c ( cycA ) activity. Together, these studies demonstrate that cycA in A. fumigatus contributes to cell death responses that are induced by exogenous H 2 O 2 and by host leukocytes.

Importance

Aspergillus fumigatus can cause a life-threatening infection known as invasive pulmonary aspergillosis (IPA), which is marked by fungus-attributable mortality rates of 20%-30%. Individuals at risk of IPA harbor genetic mutations or incur pharmacologic defects that impair myeloid cell numbers and/or function, exemplified by bone marrow transplant recipients, patients that receive corticosteroid therapy, or patients with Chronic Granulomatous Disease (CGD). However, treatments for Aspergillus infections remains limited, and resistance to the few existing drug classes is emerging. Recently, the World Health Organization (WHO) classified A. fumigatus as a critical priority fungal pathogen. Our research identifies an important aspect of fungal biology that impacts susceptibility to leukocyte killing. Furthering our understanding of mechanisms that mediate the outcome of fungal-leukocyte interactions will increase our understanding of both the underlying fungal biology governing cell death and innate immune evasion strategies utilized during mammalian infection pathogenesis. Consequently, our studies are a critical step toward leveraging these mechanisms for novel therapeutic advances.

Low Incidence of Invasive Fungal Disease Following CD19 Chimeric Antigen Receptor T-Cell (CAR-T) Therapy for Non-Hodgkin Lymphoma

CAR T-cell (CAR-T) therapy has revolutionized the treatment of hematologic malignancies, though its use may be complicated by toxicities including cytokine release syndrome (CRS), immune effector cell-associated neurotoxicity syndrome (ICANS), and infections. Invasive fungal disease (IFD) has been reported following CAR-T therapy, but the incidence in the absence of antifungal prophylaxis is unknown. Optimal screening, prophylaxis, and preemptive treatment strategies are widely debated. We performed a single-center retrospective study of 280 adults receiving CD19 CAR-T therapy for Non-Hodgkin's lymphoma (NHL) between December 2017 and September 2021 (n=280). Patients did not receive routine anti-yeast or mold prophylaxis. Proven and probable IFD was identified between day of cell infusion and last follow up. Cumulative Incidence Functions were calculated at 100 days and 18 months based on time to IFD using dates of IFD-free death, initiation of salvage treatment following relapse, and hematopoietic cell transplantation as competing risks. Eight patients (2.9%) developed IFD, including 3 Pneumocystis jirovecii pneumonia (PJP), 3 invasive mold infections (IMIs), and 2 invasive yeast infections (IYIs). Five infections (3 IMI; 2 IYI) occurred prior to day 100 and the 100-day cumulative incidence of IFD accounting for competing risks was 1.8% (95% CI 0.8 - 4.4%). Amongst the 280 patients, many developed early toxicity including CRS (85%) and ICANS (55%). Late toxicities after day 30 including grade 3/4 neutropenia (41%), hypogammaglobulinemia (35%), and low CD4 T-cell count (20%) were common. IFD was rare amongst patients who received CD19 CAR-T therapy for NHL in the absence of routine antifungal prophylaxis despite frequent toxicities including CRS, ICANS, and late neutropenia. This study suggests that in settings with low institutional rates of IFD, routine antifungal prophylaxis may not be indicated.

Neutrophil-Specific Knockdown of β2 Integrins Impairs Antifungal Effector Functions and Aggravates the Course of Invasive Pulmonal Aspergillosis

β2-integrins are heterodimeric surface receptors that are expressed specifically by leukocytes and consist of a variable α (CD11a-d) and a common β-subunit (CD18). Functional impairment of CD18, which causes leukocyte adhesion deficiency type-1 results in an immunocompromised state characterized by severe infections, such as invasive pulmonary aspergillosis (IPA). The underlying immune defects have largely been attributed to an impaired migratory and phagocytic activity of polymorphonuclear granulocytes (PMN). However, the exact contribution of β2-integrins for PMN functions in-vivo has not been elucidated yet, since the mouse models available so far display a constitutive CD18 knockout (CD18^-/- or CD18^hypo). To determine the PMN-specific role of β2-integrins for innate effector functions and pathogen control, we generated a mouse line with a Ly6G-specific knockdown of the common β-subunit (CD18^Ly6G cKO). We characterized CD18^Ly6G cKO mice in-vitro to confirm the PMN-specific knockdown of β2-integrins. Next, we investigated the clinical course of IPA in A. fumigatus infected CD18^Ly6G cKO mice with regard to the fungal burden, pulmonary inflammation and PMN response towards A. fumigatus. Our results revealed that the β2-integrin knockdown was restricted to PMN and that CD18^Ly6G cKO mice showed an aggravated course of IPA. In accordance, we observed a higher fungal burden and lower levels of proinflammatory innate cytokines, such as TNF-α, in lungs of IPA-infected CD18^Ly6G cKO mice. Bronchoalveolar lavage revealed higher levels of CXCL1, a stronger PMN-infiltration, but concomitantly elevated apoptosis of PMN in lungs of CD18^Ly6G cKO mice. Ex-vivo analysis further unveiled a strong impairment of PMN effector function, as reflected by an attenuated phagocytic activity, and a diminished generation of reactive oxygen species (ROS) and neutrophil-extracellular traps (NET) in CD18-deficient PMN. Overall, our study demonstrates that β2-integrins are required specifically for PMN effector functions and contribute to the clearance of A. fumigatus by infiltrating PMN, and the establishment of an inflammatory microenvironment in infected lungs.

Pediatric Invasive Fungal Risk Score in Cancer and Hematopoietic Stem Cell Transplantation Patients With Febrile Neutropenia

BACKGROUND

Invasive fungal diseases (IFDs) are opportunistic infections that result in significant morbidity and mortality in pediatric oncology patients. Predictive risk tools for IFD in pediatric cancer are not available.

METHODS

We conducted a 7-year retrospective study of pediatric oncology patients with a diagnosis of febrile neutropenia at UCM Comer Children's Hospitals. Fourteen clinical, laboratory, and treatment-related risk factors for IFD were analyzed. Stepwise variable selection for multiple logistic regression was used to develop a risk prediction model for IFD. Two comparative analyses have been conducted: (i) all suspected IFD cases and (ii) all proven and probable IFD cases.

RESULTS

A total of 667 febrile neutropenia episodes were identified in 265 patients. IFD was diagnosed in 62 episodes: 13 proven, 27 probable, and 22 possible. In the final multiple logistic regression models, 5 variables were independently significant for both analyses: fever days, neutropenia days, hypotension, and absolute lymphocyte count <250 at the time of diagnosis. The odds ratio and a relative weight for each factor were then calculated and summed to calculate a predictive score. A risk score of ≤4 and ≤5 (10/11 maximum) for each model signifies low risk, respectively (<1.2% incidence). Model discrimination was evaluated by the area under the receiver operator characteristics curve with an area under the curve of 0.95/0.94 for each model.

CONCLUSION

Our prediction IFD risk models perform well, are easy-to-use, and are based on readily available clinical data. Profound lymphopenia absolute lymphocyte count <250 mm3 could serve as a new important prognostic marker for the development of IFD in pediatric cancer and hematopoietic stem cell transplant patients.

Surgical resection for patients with pulmonary aspergillosis in the national inpatient sample

Background

The role of lung resection in patients with pulmonary aspergillosis is generally reserved for those with localized disease who fail medical management. We used a national database to investigate the influence of preoperative patient comorbidities on inpatient mortality and need for surgery.

Methods

Patients admitted with pulmonary aspergillosis between 2007 to 2015 were identified in the National Inpatient Sample dataset. Inpatient mortality rates were compared between patients treated medically and surgically. Predictors of mortality, surgical intervention, and non-elective admission were evaluated using multivariable logistic regression.

Results

Among a population estimate of 112,998 patients with pulmonary aspergillosis, 107,606 (95.2%) underwent medical management alone and 5,392 (4.8%) underwent surgical resection. Positive predictors for surgery included hemoptysis, and history of lung cancer or chronic pulmonary diseases. Surgically treated patients had a lower inpatient mortality when compared to those treated medically (11.5% vs. 15.1%, P<0.001) in univariate analysis, but this finding did not persist in multivariable analysis (AOR 0.97, P=0.509). The odds of mortality were lower in patients undergoing video assisted thoracoscopic surgery compared to an open approach (AOR 0.77, P=0.001). Among patients treated surgically, mortality was higher in those with a history of lung cancer, solid organ transplantation, liver disease, human immunodeficiency virus infection, hematologic diseases, chronic pulmonary diseases, and those admitted non-electively requiring surgery.

Conclusions

In this generalizable study, medical and surgical management of pulmonary aspergillosis were comparable in terms of inpatient mortality. However, non-elective admission and patients with select comorbidities have significantly worse outcomes after surgical intervention.

Diagnosis of Pneumonia Due to Invasive Molds

Pneumonia is the most common presentation of invasive mold infections (IMIs), and is pathogenetically characterized as angioinvasion by hyphae, resulting in tissue infarction and necrosis. Aspergillus species are the typical etiologic cause of mold pneumonia, with A. fumigatus in most cases, followed by the Mucorales species. Typical populations at risk include hematologic cancer patients on chemotherapy, bone marrow and solid organ transplant patients, and patients on immunosuppressive medications. Invasive lung disease due to molds is challenging to definitively diagnose based on clinical features and imaging findings alone, as these methods are nonspecific. Etiologic laboratory testing is limited to insensitive culture techniques, non-specific and not readily available PCR, and tissue biopsies, which are often difficult to obtain and impact on the clinical fragility of patients. Microbiologic/mycologic analysis has limited sensitivity and may not be sufficiently timely to be actionable. Due to the inadequacy of current diagnostics, clinicians should consider a combination of diagnostic modalities to prevent morbidity in patients with mold pneumonia. Diagnosis of IMIs requires improvement, and the availability of noninvasive methods such as fungal biomarkers, microbial cell-free DNA sequencing, and metabolomics-breath testing could represent a new era of timely diagnosis and early treatment of mold pneumonia.

Therapeutic granulocyte infusion for patients with severe neutropaenia and neutrophilic dysfunction: New Zealand experience

BACKGROUND AND OBJECTIVES

Studies have shown granulocyte transfusions (GTXs) may be beneficial in neutropaenic patients with severe systemic infections. New Zealand Blood Service has a policy for provision of granulocytes to New Zealand's District Health Boards. We set out to explore utilization of therapeutic granulocyte infusions in New Zealand.

MATERIALS AND METHODS

Patients who received GTXs in the 16-year period between 2000 and 2016 were identified by the New Zealand electronic blood management system, eProgesa. Information pertaining to recipient demographics, disease-related factors, methods of granulocyte collection and clinical outcomes was obtained by the review of electronic transfusion and clinical records.

RESULTS

Forty-five septic patients received granulocyte support for a total of 263 days. The median age of the recipients was 16 (range 0-74) years. Seventy-nine percent of the recipients had an underlying haematological malignancy with 50% having acute leukaemia. The median neutrophil count on the last day of GTX was 0.02 × 10⁹ /L (range 0-16.32). Sixty-three percent (27/43 patients with available data) had persisting severe neutropaenia when the GTXs were stopped. The median duration of support was 3 (range 1-32) days. Forty-six percent of granulocyte collections were performed via apheresis. Of the 44 patients, for whom survival outcome was available, 18 (41%) survived the acute illness.

CONCLUSION

GTXs were infrequently used, most commonly in the setting of an underlying haematological malignancy. This may be explained by the current weak evidence base supporting this therapeutic modality. Procuring a sufficiently large dose of granulocytes for infusion remains an issue for adult recipients.

Aspergillosis: Epidemiology, Diagnosis, and Treatment

The spectrum of disease produced by Aspergillus species ranges from allergic syndromes to chronic pulmonary conditions and invasive infections. Invasive aspergillosis is a major cause of morbidity and mortality in immunocompromised patients. Risk factors continue to evolve and include newer biological agents that target the immune system and postinfluenza infection; and it has been observed following COVID-19 infection. Diagnosis remains a challenge but non-culture-based methods are available. Antifungal resistance has emerged. Voriconazole remains the treatment of choice but isavuconazole and posaconazole have similar efficacy with less toxicity. Combination therapy is used with extensive infection and in severe immunosuppression.

Outcomes of Hematopoietic Cell Transplantation in Patients with Mixed Response to Pretransplantation Treatment of Confirmed or Suspected Invasive Fungal Infection

Patients with hematologic malignancy or bone marrow failure are typically required to achieve radiographic improvement or stabilization of invasive fungal infection (IFI) before hematopoietic cell transplantation (HCT) owing to a concern for progression before engraftment. Refractory IFI with a mixture of improvement and progression on serial imaging (ie, mixed response) poses a clinical dilemma, because a delay in HCT may allow for a hematologic relapse or other complications. Furthermore, HCT itself may yield the immune reconstitution necessary for clearance of infection. We sought to describe the characteristics and outcomes of patients who underwent HCT with mixed response IFI. We performed a chart review of all patients who underwent HCT between 2014 and 2020 in whom imaging within 6 weeks before HCT indicated a mixed response to treatment of a diagnosed IFI. Fourteen patients had evidence of a mixed response in low-to-moderate burden of diagnosed IFI by imaging before HCT, including 9 with pulmonary aspergillosis, 2 with hepatosplenic candidiasis (1 also with aspergillosis), and 4 with pulmonary nodules of presumed fungal etiology. Five had refractory severe neutropenia at evaluation for HCT (median, 95 days). All 14 patients showed radiographic stability or improvement in imaging following engraftment; no IFI-related surgeries were required, and no IFI-related deaths occurred. For patients without relapse who underwent HCT more than 1 year earlier, 7 of 8 (88%) were alive at 1 year. Our findings suggest that low-to-moderate burden IFI with mixed response is unlikely to progress on appropriate therapy before engraftment during allogeneic HCT.

COVID-19-associated pulmonary aspergillosis in a Japanese man: A case report

CAPA (COVID-19 associated pulmonary aspergillosis) is an important complication of COVID-19. It has been reported that the incidence of CAPA is as high as 19%–33% worldwide. However, its onset has not been reported in Japan. A 72-year-old Japanese man was diagnosed with COVID-19 and was transferred to our hospital due to deterioration of respiratory condition. Treatment with remdesivir, dexamethasone (DEXA), and antibiotics was performed under mechanical ventilation. Although the condition improved temporarily, a new shadow appeared in the lung, and Aspergillus fumigatus was cultured from sputum. The patient was clinically diagnosed with CAPA and treated with voriconazole. However, his progress deteriorated and he died. High-risk COVID-19 patients should be tested for Aspergillus to ensure early diagnosis of CAPA.

Opportunistic Invasive Fungal Infections Mimicking Progression of Non-Small-Cell Lung Cancer

BACKGROUND

Many studies have shown that invasive pulmonary aspergillosis, cryptococcosis, and mucormycosis can mimic radiographic and clinical features of primary lung cancer. However, more research surveying the incidence and outcomes of these fungal infections among patients with a history of lung cancer is needed. The aim of this study was to describe the occurrence and clinical outcomes of opportunistic invasive fungal infections that can mimic tumors in non-small-cell lung cancer patients.

PATIENTS AND METHODS

Patients seen at Stanford University Medical Center from January 1, 2007, to May 1, 2020, with pulmonary aspergillosis, cryptococcosis, or mucormycosis after non-small-cell lung cancer (NSCLC) diagnosis were reviewed. The European Organization for Research and Treatment of Cancer National Institute of Allergy and Infectious Diseases Mycoses Study Group criteria was used to classify patients with evidence of proven or probable invasive fungal infection within our cohort.

RESULTS

A total of 12 patients with proven or probable invasive mold infection (including 8 cases of aspergillosis) and 1 patient with proven cryptococcosis were identified, without any cases of mucormycosis. Of this cohort, 6 patients (46%) showed radiographic findings that were found to be most consistent with lung cancer by radiologists. Eight cases (62%) were suspected of cancer recurrence or progression by the treatment team on the basis of additional considerations of medical history and clinical symptoms. Most patients had active NSCLC or had a history of recurrence without active NSCLC at the time of fungal discovery (11 patients; 85%). Most patients died without full recovery (7 patients; 54%).

CONCLUSIONS

Invasive pulmonary aspergillosis and cryptococcosis can often be mistaken as cancer recurrence or progression in patients with a history of NSCLC because of mimicking radiographic and clinical characteristics.

Invasive fungal infections in acute myeloid leukemia treated with venetoclax and hypomethylating agents

The combination of venetoclax with hypomethylating agents (VEN-HMAs) showed promising activity in newly diagnosed and relapsed/refractory (r/r) acute myeloid leukemia (AML). Treatment with VEN-HMAs results in prolonged cytopenia, thereby exposing patients to invasive fungal infections (IFIs). Here, we retrospectively studied a cohort of 119 AML patients treated with VEN-HMAs and analyzed the occurrence of IFIs, as well as our practice of antifungal prophylaxis, with the aim to identify the nature and risk factors for IFIs and their association with the type of antifungal prophylaxis used. The intended antifungal prophylaxis was micafungin in 38% of patients, azoles in 41% of patients, and none in 21% of patients. Older age was associated with no antifungal prophylaxis or micafungin use and lesser use of azoles (P = .043). We recorded 15 (12.6%) patients who developed probable or proven IFIs, with a median onset of 72 days (range, 35-281) after starting therapy. IFIs were more common among nonresponders compared with responders to VEN-HMA therapy (22% vs 6%, P = .0132) and in r/r compared with newly diagnosed AML (19% vs 5%, P = .0498); however, the antifungal prophylaxis used, patient age, hypomethylating agent schedule, history of prior allogeneic transplant, and initial neutropenia duration did not influence the development of IFIs during therapy. We conclude that the overall risk of IFIs during VEN-HMA therapy is low. The risk of IFIs is higher in nonresponders and in those who were treated in the r/r setting; these patients need reevaluation of their antifungal prophylaxis to minimize the risk of IFIs during therapy.

An Overview of the Management of the Most Important Invasive Fungal Infections in Patients with Blood Malignancies

In patients with hematologic malignancies due to immune system disorders, especially persistent febrile neutropenia, invasive fungal infections (IFI) occur with high mortality. Aspergillosis, candidiasis, fusariosis, mucormycosis, cryptococcosis and trichosporonosis are the most important infections reported in patients with hematologic malignancies that undergo hematopoietic stem cell transplantation. These infections are caused by opportunistic fungal pathogens that do not cause severe issues in healthy individuals, but in patients with hematologic malignancies lead to disseminated infection with different clinical manifestations. Prophylaxis and creating a safe environment with proper filters and air pressure for patients to avoid contact with the pathogens in the surrounding environment can prevent IFI. Furthermore, due to the absence of specific symptoms in IFI, rapid and accurate diagnosis reduces the mortality rate of these infections and using molecular techniques along with standard mycological methods will improve the diagnosis of disseminated fungal infection in patients with hematologic disorders. Amphotericin B products, extended-spectrum azoles, and echinocandins are the essential drugs to control invasive fungal infections in patients with hematologic malignancies, and according to various conditions of patients, different results of treatment with these drugs have been reported in different studies. On the other hand, drug resistance in recent years has led to therapeutic failures and deaths in patients with blood malignancies, which indicates the need for antifungal susceptibility tests to use appropriate therapies. Life-threatening fungal infections have become more prevalent in patients with hematologic malignancies in recent years due to the emergence of new risk factors, new species, and increased drug resistance. Therefore, in this review, we discuss the different dimensions of the most critical invasive fungal infections in patients with hematologic malignancies and present a list of these infections with different clinical manifestations, treatment, and outcomes.

Influenza Suppresses Neutrophil Recruitment to the Lung and Exacerbates Secondary Invasive Pulmonary Aspergillosis

Aspergillus fumigatus is an environmental fungus that can cause invasive pulmonary aspergillosis when spores are inhaled into the respiratory tract and invade airway or lung tissue. Influenza is a common respiratory virus that can cause severe respiratory disease, and postinfluenza invasive pulmonary aspergillosis, which is becoming a well-recognized clinical problem, typically occurs in critically ill patients. Mice challenged with influenza A PR/8/34 H1N1 and subsequently challenged with A. fumigatus had increased fungal burden, viral burden, inflammation, and mortality compared with single infected mice. Neutrophil recruitment in the lung of superinfected mice was decreased; however, mice were not neutropenic, and there was no difference in absolute blood neutrophils between groups. Additionally, CXCL1 and CXCL2 were decreased in lungs of superinfected mice compared with controls. IFN levels were increased in mice that received influenza, and deletion of STAT1 resulted in decreased fungal burden, increased airway and lung neutrophils, and increased CXCL1 compared with wild-type mice, whereas deletion of STAT2 did not change fungal burden or airway neutrophilia compared with wild-type mice. These data demonstrate a mechanism by which influenza A-induced STAT1 signaling inhibits neutrophil recruitment and increases susceptibility to postinfluenza invasive pulmonary aspergillosis.

Biology and function of exo-polysaccharides from human fungal pathogens

Purpose of review

Environmental fungi such as Cryptococcus neoformans and Aspergillus fumigatus must survive many different and changing environments as they transition from their environmental niches to human lungs and other organs. Fungi alter their cell surfaces and secreted macromolecules to respond to and manipulate their surroundings.

Recent findings

This review focuses on exo-polysaccharides, chains of sugars that transported out of the cell and spread to the local environment. Major exo-polysaccharides for C. neoformans and A. fumigatus are glucuronylxylomannan (GXM) and galactosaminogalactan (GAG), respectively, which accumulate at high concentrations in growth medium and infected patients.

Summary

Here we discuss GXM and GAG synthesis and export, their immunomodulatory properties, and their roles in biofilm formation. We also propose areas of future research to address outstanding questions in the field that could facilitate development of new disease treatments.

Work-up for Fever During Neutropenia for Both the Stem Cell Transplant Recipient and the Hematologic Malignancy Patient

Fever is a common complication in patients with underlying neutropenia and is associated with significant mortality in neutropenic patients with acute myelogenous leukemia or hematopoietic cell transplant. Fever may be the only sign of infection and requires further clinical assessment, including a history, a physical examination, and additional laboratory and radiographic testing. National and international guidelines recommend initiation of empiric antimicrobial therapy in patients with fever during neutropenia. Stepwise escalation of antibacterial therapy, followed by antifungal therapy for patients with persistent fever, generally is recommended. Consideration should also be given to de-escalation of antimicrobial therapy in the appropriate clinical settings.

The Emergence of Rare Clinical Aspergillus Species in Qatar: Molecular Characterization and Antifungal Susceptibility Profiles

Aspergillus are ubiquitous mold species that infect immunocompetent and immunocompromised patients. The symptoms are diverse and range from allergic reactions, bronchopulmonary infection, and bronchitis, to invasive aspergillosis. The aim of this study was to characterize 70 Aspergillus isolates recovered from clinical specimens of patients with various clinical conditions presented at Hamad general hospital in Doha, Qatar, by using molecular methods and to determine their in vitro antifungal susceptibility patterns using the Clinical and Laboratory Standards Institute (CLSI) M38-A2 reference method. Fourteen Aspergillus species were identified by sequencing β-tubulin and calmodulin genes, including 10 rare and cryptic species not commonly recovered from human clinical specimens. Aspergillus welwitschiae is reported in this study for the first time in patients with fungal rhinosinusitis (n = 6) and one patient with a lower respiratory infection. Moreover, Aspergillus pseudonomius is reported in a patient with fungal rhinosinusitis which is considered as the first report ever from clinical specimens. In addition, Aspergillus sublatus is reported for the first time in a patient with cystic fibrosis. In general, our Aspergillus strains exhibited low MIC values for most of the antifungal drugs tested. One strain of Aspergillus fumigatus showed high MECs for echinocandins and low MICs for the rest of the drugs tested. Another strain of A. fumigatus exhibited high MIC for itraconazole and categorized as non-wild type. These findings require further analysis of their molecular basis of resistance. In conclusion, reliable identification of Aspergillus species is achieved by using molecular sequencing, especially for the emerging rare and cryptic species. They are mostly indistinguishable by conventional methods and might exhibit variable antifungal susceptibility profiles. Moreover, investigation of the antifungal susceptibility patterns is necessary for improved antifungal therapy against aspergillosis.

How Environmental Fungi Cause a Range of Clinical Outcomes in Susceptible Hosts

Environmental fungi are globally ubiquitous and human exposure is near universal. However, relatively few fungal species are capable of infecting humans, and among fungi, few exposure events lead to severe systemic infections. Systemic infections have mortality rates of up to 90%, cost the US healthcare system $7.2 billion annually, and are typically associated with immunocompromised patients. Despite this reputation, exposure to environmental fungi results in a range of outcomes, from asymptomatic latent infections to severe systemic infection. Here we discuss different exposure outcomes for five major fungal pathogens: Aspergillus, Blastomyces, Coccidioides, Cryptococcus, and Histoplasma species. These fungi include a mold, a budding yeast, and thermal dimorphic fungi. All of these species must adapt to dramatically changing environments over the course of disease. These dynamic environments include the human lung, which is the first exposure site for these organisms. Fungi must defend themselves against host immune cells while germinating and growing, which risks further exposing microbe-associated molecular patterns to the host. We discuss immune evasion strategies during early infection, from disruption of host immune cells to major changes in fungal cell morphology.

Clinical risk score for invasive fungal diseases in patients with hematological malignancies undergoing chemotherapy: China Assessment of Antifungal Therapy in Hematological Diseases (CAESAR) study

Invasive fungal disease (IFD) is a major infectious complication in patients with hematological malignancies. In this study, we examined 4889 courses of chemotherapy in patients with hematological diseases to establish a training dataset (n = 3500) by simple random sampling to develop a weighted risk score for proven or probable IFD through multivariate regression, which included the following variables: male patients, induction chemotherapy for newly diagnosed or relapsed disease, neutropenia, neutropenia longer than 10 days, hypoalbuminemia, central-venous catheter, and history of IFD. The patients were classified into three groups, which had low (0-10, ~1.2%), intermediate (11-15, 6.4%), and high risk ( > 15, 17.5%) of IFD. In the validation set (n = 1389), the IFD incidences of the groups were ~1.4%, 5.0%, and 21.4%. In addition, we demonstrated that antifungal prophylaxis offered no benefits in low-risk patients, whereas benefits were documented in intermediate (2.1% vs. 6.6%, P = 0.007) and high-risk patients (8.4% vs. 23.3%, P = 0.007). To make the risk score applicable for clinical settings, a pre-chemo risk score that deleted all unpredictable factors before chemotherapy was established, and it confirmed that anti-fungal prophylaxis was beneficial in patients with intermediate and high risk of IFD. In conclusion, an objective, weighted risk score for IFD was developed, and it may be useful in guiding antifungal prophylaxis.

A Retrospective Study of Comorbidities and Complications in Elderly Acute Myeloid Leukemia Patients in the United States

BACKGROUND

Comorbidities in acute myeloid leukemia (AML) patients have been shown to increase with age. However, few studies have described the disease burden in elderly AML patients, a population generally underrepresented in clinical trials. We aimed to characterize the comorbidities and complications in elderly AML patients.

PATIENTS AND METHODS

Patients aged ≥ 65 years with a primary diagnosis of AML were identified from the Surveillance, Epidemiology, and End Results (SEER)-Medicare linked database (2000-2013) and were followed until the end of 2014. AML patients were matched 1:1 to noncancer patients by age, sex, geographic region, and race. A subset of patients with relapsed and/or refractory (R/R) AML was identified by modifying a previously validated algorithm. Baseline comorbidities and complications (eg, infectious, hematologic, cardiovascular) during follow-up were assessed using ICD-9 codes. Cox proportional hazards models were used to determine associations between AML and developing select complications.

RESULTS

Compared to matched noncancer controls, AML patients (n = 3911) had higher baseline National Cancer Institute comorbidity index scores (1.81 vs. 1.63, P < .01), higher incidence rates (per 100 person-years) for all events of interest, and a higher risk of developing cardiovascular disease (hazard ratio = 4.61; 95% confidence interval, 4.07-5.21), type 2 diabetes mellitus (hazard ratio = 3.85; 95% confidence interval, 3.35-4.42), and stroke (hazard ratio = 2.60; 95% confidence interval, 2.32-2.92). R/R AML patients were younger, had lower National Cancer Institute comorbidity scores, lower incidence rates of events of interest, and a longer follow-up time compared to non-R/R AML patients.

CONCLUSION

Elderly AML patients had more comorbidities and higher rates of complications compared to noncancer controls. Considering comorbidities and complications in elderly AML patients may improve clinical decision making.

Indian Antimicrobial Prescription Guidelines in Critically Ill Immunocompromised Patients

How to cite this article: Kulkarni AP, Sengar M, Chinnaswamy G, Hegde A, Rodrigues C, Soman R, Khilnani GC, Ramasubban S, Desai M, Pandit R, Khasne R, Shetty A, Gilada T, Bhosale S, Kothekar A, Dixit S, Zirpe K, Mehta Y, Pulinilkunnathil JG, Bhagat V, Khan MS, Narkhede AM, Baliga N, Ammapalli S, Bamne S, Turkar S, Bhat KV, Choudhary J, Kumar R, Divatia JV. Indian Journal of Critical Care Medicine 2019;23(Suppl 1): S64-S96.

Development and Applications of Prognostic Risk Models in the Management of Invasive Mold Disease

Prognostic models or risk scores are frequently used to aid individualize risk assessment for diseases with multiple, complex risk factors and diagnostic challenges. However, relatively little attention has been paid to the development of risk models for invasive mold diseases encountered in patients with hematological malignancies, despite a large body of epidemiological research. Herein we review recent studies that have described the development of prognostic models for mold disease, summarize our experience with the development and clinical use of one such model (BOSCORE), and discuss the potential impact of prognostic risk scores for individualized therapy, diagnostic and antifungal stewardship, as well as clinical and epidemiological research.

Invasive mediastinal aspergillosis presenting as superior vena cava syndrome in an immunocompetent patient

Invasive aspergillosis (IA) is a disease of the immunocompromised with a predilection for the lungs, although dissemination to all organs is possible. Its diagnosis remains a challenge due to the absence of specific clinical manifestations and laboratory findings. In most cases, diagnosis is eventually made via invasive methods. It carries with it a high mortality due to late diagnosis and delayed treatment. Here, we report a fascinating case of a young, otherwise healthy, immunocompetent patient that presented to us with superior vena cava syndrome and a mediastinal mass. It was anticipated that a malignancy would be found on further workup but, in fact, what was eventually discovered was a case of IA. Our report accentuates the significance of including IA as a differential while diagnosing a mediastinal mass in an immunocompetent host as patient outcome is determined by timely diagnosis and treatment.

Invasive Aspergillosis in Children: Update on Current Guidelines

Invasive aspergillosis (IA) is an important cause of infectious morbidity and mortality in immunocompromised paediatric patients. Despite improvements in diagnosis, prevention, and treatment, IA is still associated with high mortality rates. To address this issue, several international societies and organisations have proposed guidelines for the management of IA in the paediatric population. In this article, we review current recommendations of the Infectious Diseases Society of America, the European Conference on Infection in Leukaemia and the European Society of Clinical Microbiology and Infectious Diseases for the management and prevention of IA in children.

Risk Factors for Invasive Fungal Disease in Pediatric Cancer and Hematopoietic Stem Cell Transplantation: A Systematic Review

BACKGROUND

Although a number of risk factors have been associated with invasive fungal disease (IFD), a systematic review of the literature to document pediatric-specific factors has not been performed.

METHODS

We used the Ovid SP platform to search Medline, Medline In-Process, and Embase for studies that identified risk factors for IFD in children with cancer or those who undergo hematopoietic stem cell transplantation (HSCT). We included studies if they consisted of children or adolescents (<25 years) who were receiving treatment for cancer or undergoing HSCT and if the study evaluated risk factors among patients with and those without IFD.

RESULTS

Among the 3566 studies screened, 22 studies were included. A number of pediatric factors commonly associated with an increased risk for IFD were confirmed, including prolonged neutropenia, high-dose steroid exposure, intensive-timing chemotherapy for acute myeloid leukemia, and acute and chronic graft-versus-host disease. Increasing age, a factor not commonly associated with IFD risk, was identified as a risk factor in multiple published cohorts.

CONCLUSIONS

With this systematic review, we have confirmed IFD risk factors that are considered routinely in daily clinical practice. Increasing age should also be considered when assessing patient risk for IFD. Future efforts should focus on defining more precise thresholds for a particular risk factor (ie, age, neutropenia duration) and on development of prediction rules inclusive of individual factors to further refine the risk prediction.

Infectious Risks and Complications in Adult Leukemic Patients Receiving Blinatumomab

Background

Blinatumomab is an anti-CD19 immunotherapy approved for relapsed/refractory B-cell acute lymphoblastic leukemia (ALL) with significantly increased survival rate. While blinatumomab showed lower rates of infection, neutropenia and mucosal barrier injury versus chemotherapy, its infection risks are not well described.

Methods

All patients who received blinatumomab for ≥ seven days at an academic cancer center from May 2015 to April 2017 were included. Patient characteristics pertinent to infectious risks and complications were examined.

Results

Twenty patients with refractory (25%), relapsed (70%), or remitted (5%) B-ALL who received a total of 35 cycles were included. Ten of the 35 cycles were interrupted, none of which were due to infections. Twenty-six infections (n) were observed with lower respiratory (9), gastrointestinal (6) and bacteremia (5) being most common. Compared to patients without nodular, possible mold pneumonia (n=16), patients with nodular pneumonia (n=4) had significantly lower baseline absolute neutrophil count (ANC) (2319 v. 208/μL, p=0.011). There were no differences in baseline characteristics including ANC between bacteremic and non-bacteremic patients. One patient was discharged with no antibacterial prophylaxis since ANC recovered to >500cells/μL, but developed Pseudomonal bacteremia within a week with ANC ~100cells/μL.

Conclusion

Despite blinatumomab's relatively modest myelosuppression and the lack of mucotoxicity, host factors (e.g., duration and degree of neutropenia/lymphopenia) play a key role and should be considered when choosing anti-microbial prophylaxis. In relapsed/refractory disease, the ANC should be monitored closely post blinatumomab since neutropenia can unexpectedly develop after treatment which may be compounded by the underlying disease and recent chemotherapy effects.

Neutrophil extracellular traps in fungal infection

Fungal infections are a continuously increasing problem in modern health care. Understanding the complex biology of the emerging pathogens and unraveling the mechanisms of host defense may form the basis for the development of more efficient diagnostic and therapeutic tools. Neutrophils play a pivotal role in the defense against fungal pathogens. These phagocytic hunters migrate towards invading fungal microorganisms and eradicate them by phagocytosis, oxidative burst and release of neutrophil extracellular traps (NETs). In the last decade, the process of NET formation has received unparalleled attention, with numerous studies revealing the relevance of this neutrophil function for control of various mycoses. Here, we describe NET formation and summarize its role as part of the innate immune defense against fungal pathogens. We highlight factors influencing the formation of these structures and molecular mechanisms employed by fungi to impair the formation of NETs or subvert their antifungal effects.

Sterilizing immunity in the lung relies on targeting fungal apoptosis-like programmed cell death

Humans inhale mold conidia daily and typically experience lifelong asymptomatic clearance. Conidial germination into tissue-invasive hyphae can occur in individuals with defects in myeloid function, although the mechanism of myeloid cell-mediated immune surveillance remains unclear. By monitoring fungal physiology in vivo, we demonstrate that lung neutrophils trigger programmed cell death with apoptosis-like features in Aspergillus fumigatus conidia, the most prevalent human mold pathogen. An antiapoptotic protein, AfBIR1, opposes this process by inhibiting fungal caspase activation and DNA fragmentation in the murine lung. Genetic and pharmacologic studies indicate that AfBIR1 expression and activity underlie conidial susceptibility to NADPH (reduced form of nicotinamide adenine dinucleotide phosphate) oxidase-dependent killing and, in turn, host susceptibility to invasive aspergillosis. Immune surveillance exploits a fungal apoptosis-like programmed cell death pathway to maintain sterilizing immunity in the lung.

New insights into the clinical characteristics and prognostic factors of pulmonary fungal infections from a retrospective study in Southwestern China

Background

Despite increasing incidence of pulmonary fungal infections (PFIs) worldwide, the clinical characteristics and prognostic factors remain poorly understood. The goal of this study was to investigate the clinical features, laboratory findings, and outcomes of hospitalized patients diagnosed with PFIs.

Methods

We retrospectively enrolled 123 patients at a university hospital in Southwestern China between February 2014 and May 2016, who were diagnosed with PFIs based on clinical presentations and laboratory tests including fungal culture and pathological examination. Medical records were reviewed and analyzed. Prognostic factor associated with mortality was evaluated by multivariate regression analysis.

Results

Of the 123 PFI patients enrolled, the mean age was 67 years with 72% of them being males. In addition to common clinical features reported previously, these patients exhibited distinct characteristics, with the elderly accounting for 79% of all cases, and with prolonged hospitalization being the most prevalent risk factor (74%) and chronic obstructive pulmonary disease (COPD) being the most common underlying disease (45%). Invasive operation was significantly more frequently involved in patients with unfavorable treatment responses than in patients with favorable responses (45.6 vs 7.4%, P=0.000). By multivariate regression analysis, invasive operation (odds ratio [OR]: 5.736, 95% confidence interval [CI]: 2.008–16.389, P=0.001) and hypoalbuminemia (OR: 3.936, 95% CI: 1.325–11.696, P=0.014) were independent prognostic factors of mortality in PFIs.

Conclusion

This study provides new insights into the clinical characteristics and prognostic factors of PFIs and highlights the necessity to be aware of PFIs in patients with COPD and patients receiving invasive operation in order to improve clinical management of these patients.

The Interface between Fungal Biofilms and Innate Immunity

Fungal biofilms are communities of adherent cells surrounded by an extracellular matrix. These biofilms are commonly found during infection caused by a variety of fungal pathogens. Clinically, biofilm infections can be extremely difficult to eradicate due to their resistance to antifungals and host defenses. Biofilm formation can protect fungal pathogens from many aspects of the innate immune system, including killing by neutrophils and monocytes. Altered immune recognition during this phase of growth is also evident by changes in the cytokine profiles of monocytes and macrophages exposed to biofilm. In this manuscript, we review the host response to fungal biofilms, focusing on how these structures are recognized by the innate immune system. Biofilms formed by Candida, Aspergillus, and Cryptococcus have received the most attention and are highlighted. We describe common themes involved in the resilience of fungal biofilms to host immunity and give examples of biofilm defenses that are pathogen-specific.

Modulation of Immune Signaling and Metabolism Highlights Host and Fungal Transcriptional Responses in Mouse Models of Invasive Pulmonary Aspergillosis

Incidences of invasive pulmonary aspergillosis, an infection caused predominantly by Aspergillus fumigatus, have increased due to the growing number of immunocompromised individuals. While A. fumigatus is reliant upon deficiencies in the host to facilitate invasive disease, the distinct mechanisms that govern the host-pathogen interaction remain enigmatic, particularly in the context of distinct immune modulating therapies. To gain insights into these mechanisms, RNA-Seq technology was utilized to sequence RNA derived from lungs of 2 clinically relevant, but immunologically distinct murine models of IPA on days 2 and 3 post inoculation when infection is established and active disease present. Our findings identify notable differences in host gene expression between the chemotherapeutic and steroid models at the interface of immunity and metabolism. RT-qPCR verified model specific and nonspecific expression of 23 immune-associated genes. Deep sequencing facilitated identification of highly expressed fungal genes. We utilized sequence similarity and gene expression to categorize the A. fumigatus putative in vivo secretome. RT-qPCR suggests model specific gene expression for nine putative fungal secreted proteins. Our analysis identifies contrasting responses by the host and fungus from day 2 to 3 between the two models. These differences may help tailor the identification, development, and deployment of host- and/or fungal-targeted therapeutics.