Epidemiology of Aspergillus infections in a large cohort of patients undergoing bone marrow transplantation

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.

Age difference of patients with and without invasive aspergillosis: a systematic review and meta-analysis

BACKGROUND

Invasive Aspergillosis (IA) is a life-threatening fungal disease with significant mortality rates. Timely diagnosis and treatment greatly enhance patient outcomes. This study aimed to explore the association between patient age and the development of IA, as well as the potential implications for risk stratification strategies.

METHODS

We searched National Center for Biotechnology Information (NCBI) databases for publications until October 2023 containing age characteristics of patients with and without IA. A random-effects model with the application of inverse-variance weighting was used to pool reported estimates from each study, and meta-regression and subgroup analyses were utilized to assess sources of heterogeneity.

RESULTS

A systematic review was conducted, resulting in the inclusion of 55 retrospective observational studies with a total of 13,983 patients. Meta-analysis revealed that, on average, patients with IA were approximately two and a half years older (95% Confidence Interval [CI] 1.84-3.31 years; I2 = 26.1%) than those without the disease (p < 0.0001). No significant moderators could explain the observed heterogeneity in age difference. However, subgroup analysis revealed that age differences were more pronounced within particular patient groups compared to others. For example, patients with and without IA who had primary severe lung infections exhibited a greater difference in mean age than other patient cohorts.

CONCLUSIONS

Further research, such as individual patient data meta-analysis, is necessary to better understand the potential relationship between increasing age and the likelihood of IA. Improved risk stratification strategies based on patient age could potentially enhance the early detection and treatment of IA, ultimately improving patient outcomes.

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.

The changing epidemiology of fungal infections

Invasive fungal diseases are common complications in critically ill patients and in those with significant underlying imbalanced immune systems. Fungal co-, and/or super-infections are emerging and have become a rising concern within the last few years. In Europe, cases of candidiasis and aspergillosis dominate, followed by mucormycosis in India. Epidemiological studies show an increasing trend in the incidence of all three entities. Parallel to this, a shift within the underlying fungal pathogens is observed. More non-albicans Candida infections and aspergillosis with cryptic species are on the rise; cryptic species may cover intrinsic resistance to azoles and other antifungal drugs. The recent COVID-19 pandemic led to a significantly increasing incidence of invasive fungal diseases among hospitalized patients.

Diagnosis and Treatment of Invasive Aspergillosis Caused by Non-fumigatus Aspergillus spp

With increasing frequency, clinical and laboratory-based mycologists are consulted on invasive fungal diseases caused by rare fungal species. This review aims to give an overview of the management of invasive aspergillosis (IA) caused by non-fumigatus Aspergillus spp.-namely A. flavus, A. terreus, A. niger and A. nidulans-including diagnostic and therapeutic differences and similarities to A. fumigatus. A. flavus is the second most common Aspergillus spp. isolated in patients with IA and the predominant species in subtropical regions. Treatment is complicated by its intrinsic resistance against amphotericin B (AmB) and high minimum inhibitory concentrations (MIC) for voriconazole. A. nidulans has been frequently isolated in patients with long-term immunosuppression, mostly in patients with primary immunodeficiencies such as chronic granulomatous disease. It has been reported to disseminate more often than other Aspergillus spp. Innate resistance against AmB has been suggested but not yet proven, while MICs seem to be elevated. A. niger is more frequently reported in less severe infections such as otomycosis. Triazoles exhibit varying MICs and are therefore not strictly recommended as first-line treatment for IA caused by A. niger, while patient outcome seems to be more favorable when compared to IA due to other Aspergillus species. A. terreus-related infections have been reported increasingly as the cause of acute and chronic aspergillosis. A recent prospective international multicenter surveillance study showed Spain, Austria, and Israel to be the countries with the highest density of A. terreus species complex isolates collected. This species complex seems to cause dissemination more often and is intrinsically resistant to AmB. Non-fumigatus aspergillosis is difficult to manage due to complex patient histories, varying infection sites and potential intrinsic resistances to antifungals. Future investigational efforts should aim at amplifying the knowledge on specific diagnostic measures and their on-site availability, as well as defining optimal treatment strategies and outcomes of non-fumigatus aspergillosis.

Infection-related mortality after HLA-identical and haploidentical hematopoietic cell transplantation using reduced-intensity conditioning in an outpatient setting

BACKGROUND

Despite the improvements in supportive care for allogeneic-hematopoietic cell transplantation (allo-HCT) recipients, infectious complications and infection-related mortality (IRM) continue to be a major issue for transplantation centers.

METHODS

We herein report the infectious complications and IRM of 107 and 89 patients that underwent haploidentical (haplo-HCT) or HLA-identical HCT at a tertiary referral center during 2013-2020. Patients in the haplo-HCT group received post-transplant cyclophosphamide (PT-Cy), and all received reduced-intensity conditioning regimens.

RESULTS

More haplo-HCT recipients presented severe infections in the pre-engraftment period (22.4% vs. 6.7%, p = 0.003). Viral (14.9% vs. 4.5%, p = 0.016) and fungal (12.1% vs. 1.1%, p = 0.003) etiologies were more common in this period in this group. The 100-day and 2-year cumulative incidence of IRM was 15% and 21% for the haplo-HCT and 5.6% and 17% for the HLA-identical group; no significant differences were observed between the groups. Fungal pathogens mainly contributed to IRM (33.3%). Infections were the most common cause of mortality (40/81, 49.4%). There were significant differences in donor/recipient CMV serostatus between transplant groups (0.002).

CONCLUSIONS

No differences in IRM were observed based on allo-HCT type, with more haplo-HCT patients suffering from severe infections in the pre-engraftment period. Studies to assess future prevention, diagnostic, and treatment strategies to reduce IRM are warranted.

The association of HLA-DRB1 alleles and MBL2 gene variant in pediatric acute lymphoblastic leukemia patients

INTRODUCTION

Epidemiologic studies on pediatric acute lymphoblastic leukemias (ALL) have been conducted to evaluate the possible risk factors including genetic, infectious and environmental factors with the objective of idenfying the etiology. Mannose-binding lectin 2 (MBL2) plays an important role in first-line immune defense. HLA DRB1 alleles play a role in presentation of peptides to T cells and in activation of the adaptive immune response.

OBJECTIVE

In our study, we aimed to investigate both the MBL2 gene variant and HLA-DRB1 alleles in pediatric ALL patients.

MATERIALS

In this study, 86 high-risk ALL patients and 100 controls were included. Polymerase Chain Reaction (PCR)-Restriction Fragment Length Polymorphism (PCR-RFLP) and PCR-sequence specific primer (SSP) methods were used for detection of polymorphism of the MBL2 and HLA-DRB1 alleles, respectively.

RESULTS

The frequency of the MBL2 AB genotype was lower in female ALL patients, compared to male ALL patients (p = 0.034). An association was found between the MBL2 BB genotype and DRB1*07 and among patients with the MBL2 BB genotype; those who also carried the DRB1*07 and *04 alleles were significantly higher than those without the DRB1*07 and *04 alleles. (p = 0.048, p = 0.022, respectively).

CONCLUSION

This is the first study suggesting that the MBL2 BB genotype in association with the DRB1*07 or co-inheritance of the HLA-DRB1*04 and HLA DRB1*07 may have an impact on the etiopathogenesis of the disease.

Neutropenia-related aspergillosis in non-transplant haematological patients hospitalised under ambient air versus purified air conditions

BACKGROUND

To reduce the risk of invasive aspergillosis (IA), air purification by high-efficiency particulate air filtration and laminar air flow (HEPA/LAF) is standard of care in allogeneic blood stem cell transplantation. Its use in non-transplant haematological patients is inconsistent.

OBJECTIVES

We sought to assess the incidence and outcome of pulmonary IA in non-transplant patients with life-threatening neutropenia by comparing an ambient air hospitalisation period (2008-2011) with a subsequent HEPA/LAF hospitalisation period (2012-2014).

PATIENTS AND METHODS

We compared 204 consecutive patients with acute myeloid leukaemia, acute lymphoblastic leukaemia or aplastic anaemia completing 534 neutropenia-related hospitalisations under ambient air conditions with 126 such patients completing 437 neutropenia-related hospitalisations under HEPA/LAF conditions. IA was defined using the 2008 EORTC/MSG criteria.

RESULTS

Within a 7-year study period, we observed one 'proven', three 'probable' and 73 'possible' IAs, most often during acute leukaemia remission induction. Their frequency rose with increasing duration of life-threatening neutropenia (1-10 days, 1.8%; >40 days, 35.2%) and concomitant severe anaemia (0 days, 3.2%; >20 days, 31.0%). Multiple logistic regression revealed a strong correlation between IA incidence and hospitalisation under HEPA/LAF conditions (odds ratio [OR], 0.368 [95% confidence interval, 0.207-0.654]; p < .001) and duration of neutropenia (OR, 1.043 [1.023-1.062] per day; p < .001) and anaemia (OR, 1.044 [1.008-1.081] per day; p = .016). IA-associated fatal outcomes were non-significantly reduced under HEPA/LAF (OR, 0.077 [0.005-1.151]; p = .063). The protective effect of HEPA/LAF was not seen under posaconazole prophylaxis (OR, 0.856 [0.376-1.950]; p = .711).

CONCLUSIONS

Implementation of HEPA/LAF was associated with a significant reduction in neutropenia-related IA in non-transplant haematological patients.

Sequential low-dose CT thorax scans to determine invasive pulmonary fungal infection incidence after allogeneic hematopoietic cell transplantation

Invasive fungal disease (IFD) during neutropenia goes along with a high mortality for patients after allogeneic hematopoietic cell transplantation (alloHCT). Low-dose computed tomography (CT) thorax shows good sensitivity for the diagnosis of IFD with low radiation exposure. The aim of our study was to evaluate sequential CT thorax scans at two time points as a new reliable method to detect IFD during neutropenia after alloHCT. We performed a retrospective single-center observational study in 265/354 screened patients admitted for alloHCT from June 2015 to August 2019. All were examined by a low-dose CT thorax scan at admission (CT t₀) and after stable neutrophil recovery (CT t₁) to determine the incidences of IFD. Furthermore, antifungal prophylaxis medications were recorded and cohorts were analyzed for statistical differences in IFD incidence using the sequential CT scans. In addition, IFD cases were classified according to EORTC 2008. At CT t₀ in 9.6% of the patients, an IFD was detected and antifungal therapy initiated. The cumulative incidence of IFD in CT t₁ in our department was 14%. The use of Aspergillus-effective prophylaxis through voriconazole or posaconazole decreased CT thorax t₁ suggesting IFD is statistically significant compared to prophylaxis with fluconazole (5.6% asp-azol group vs 16.3% fluconazole group, p = 0.048). In 86%, CT t₁ was negative for IFD. Low-dose sequential CT thorax scans are a valuable tool to detect pulmonary IFDs and guide antifungal prophylaxis and therapies. Furthermore, a negative CT t₁ scan shows a benefit by allowing discontinuation of antifungal medication sparing patients from drug interactions and side effects.

Neuroimmune Responses in a New Experimental Animal Model of Cerebral Aspergillosis

Exposure of immunosuppressed individuals to the opportunistic fungal pathogen Aspergillus fumigatus may result in invasive pulmonary aspergillosis (IPA), which can lead to the development of cerebral aspergillosis (CA), a highly lethal infection localized in the central nervous system (CNS). There are no experimental models of CA that effectively mimic human disease, resulting in a considerable knowledge gap regarding mechanisms of neurological pathogenicity and neuroimmune responses during infection. In this report, immunosuppressed mice (via acute, high-dose corticosteroid administration) challenged with A. fumigatus resting conidia intranasally, followed a day later by a 70-fold lower inoculum of pre-swollen conidia intravenously (IN + IV + steroid), demonstrated increased weight loss, signs of severe clinical disease, increased fungal burden in the brain, and significant reduction in survival compared to immunosuppressed mice challenged intranasally only (IN + steroid) or non-immunosuppressed mice challenged both intranasally and intravenously (IN + IV). The IN + IV + steroid group demonstrated significant decreases in monocytes, eosinophils, dendritic cells (DCs), and invasive natural killer T (iNKT) cells, but not neutrophils or γδ T cells, in the brain compared to the IN + IV group. Likewise, the IN + IV + steroid group had significantly lower levels of interleukin (IL)-1β, IL-6, IL-17A, CC motif chemokine ligand 3 (CCL3), CXC chemokine ligand 10 (CXCL10), and vascular endothelial growth factor (VEGF) in the brain compared to the IN + IV group. IN + IV + steroid was superior to both IN + IV + chemotherapy (cytarabine + daunorubicin) and IN + IV + neutropenia for the development of CA. In conclusion, we have developed a well-defined, physiologically relevant model of disseminated CA in corticosteroid-induced immunosuppressed mice with a primary pulmonary infection. This model will serve to advance understanding of disease mechanisms, identify immunopathogenic processes, and help define the protective neuroinflammatory response to CA. IMPORTANCE Invasive fungal infections (IFIs) result in significant mortality in immunosuppressed individuals. Of these, invasive pulmonary aspergillosis (IPA), caused by the opportunistic mold Aspergillus fumigatus, is the most lethal. Lethality in IPA is due to two main factors: destruction of the lung leading to compromised pulmonary function, and dissemination of the organism to extrapulmonary organs. Of these, the CNS is the most common site of dissemination. However, very little is known regarding the pathogenesis of or immune response during cerebral aspergillosis, which is directly due to the lack of an animal model that incorporates immunosuppression, lung infection, and consistent dissemination to the CNS/brain. In this report, we have developed a new experimental animal model of CA which includes the above parameters and characterized the neuroimmune response. We further compared this disseminated CA model to two additional immunosuppressive strategies. Overall, this model of disseminated CA following IPA in an immunosuppressed host provides a novel platform for studying the efficacy of antifungal drugs and immunotherapies for improving disease outcomes.

Infection as a Differential Diagnosis of Solid Retroperitoneal Masses: A Case Series and Review of the Literature

The differential diagnosis of retroperitoneal masses includes a variety of benign and malignant conditions, among which infections constitute a significant subgroup. Familiarity with these infectious pseudotumours could facilitate prompt diagnosis. In this report, we describe three patients with an infectious pseudotumour, which was clinically and radiologically highly suggestive of a neoplasm.

The first patient was a 62-year-old woman with a history of Richter syndrome, who seven months after allogeneic haematopoetic stem cell transplantation from an unrelated donor presented with a renal mass. A renal biopsy at that time revealed necrotic tissue. The patient displayed multiple relapses of Richter syndrome (for which she received also chimeric antigen receptor T-cell therapy salvage chemotherapy) and remissions of the lymphoma as well as an Aspergillus pneumonia for which she was treated with intravenous ambisome and afterwards oral posaconazole. Since the renal mass persisted and to exclude malignancy, nephrectomy was performed which revealed the presence of fungal hyphae.

The second patient was a 51-year-old man with a history of a low-grade non-muscle-invasive bladder urothelial carcinoma, who after Mycobacterium bovis Calmette-Guerin instillation presentedwith fever and a suspicious renal mass. A partial nephrectomy was performed. Intraoperative frozen section analysis and routine histology suggested a Mycobacterium bovis-associated lesion, which was confirmed by polymerase chain reaction (PCR) analysis.

The third patient was an 85-year-old man who presented with loss of appetite, fatigue, and significant weight loss (24 Kg in less than a year) as well as a travel history. The laboratory tests showed a low sodium and a high potassium level. CT scans revealed a solitary lesion in the right lung, a small liver lesion as well as bilateral adrenal lesions. A CT-guided biopsy revealed the presence of Histoplasma capsulatum, which was confirmed by PCR analysis. A retrospective review of all parameters indicates that all three patients presented with some risk factors, such as immunosuppression, travel, or clinical history that could raise the suspicion of infection in order to be included in the differential diagnosis, thus providing an additional tool for timely diagnosis.

The association of cytomegalovirus infection and cytomegalovirus serostatus with invasive fungal infections in allogeneic haematopoietic stem cell transplant recipients: a systematic review and meta-analysis

BACKGROUND

In allogeneic haematopoietic stem cell transplant (allo-HSCT) recipients, the inter-relationship between post-transplant cytomegalovirus (CMV) and subsequent invasive fungal infections (IFIs) is conflicting and the association of CMV serostatus with IFIs has not been evaluated.

OBJECTIVES

To determine the relationship between CMV infection/serostatus and IFIs in allo-HSCT populations.

DATA SOURCES

A systematic literature search was conducted from existence until 11 July 2021 using Medline, Embase and ISI Web of Science databases.

STUDY ELIGIBILITY CRITERIA

Cross-sectional, prospective cohort, retrospective cohort and case-control studies that reported allo-HSCT recipients with CMV and without CMV who developed or did not develop IFIs after CMV infection.

PARTICIPANTS

Allo-HSCT recipients.

INTERVENTIONS

Not applicable.

METHODS

A systematic search, screening, data extracting and assessing study quality were independently conducted by two reviewers. The Newcastle-Ottawa scale was used to assess risk of bias. data were analysed using the pooled effect estimates of a random-effects model.

RESULTS

A total of 18 and 12 studies were included for systematic review and meta-analysis, respectively. Post-transplant CMV infection significantly increased the risk of IFIs with a pooled hazard ratio (pHR) of 2.58 (1.78, 3.74), I² = 75%. Further subgroup analyses by timing of IFIs, CMV definitions, study continents, study design and adjustment of effect estimates showed that post-transplant CMV infection consistently increased the risk of subsequent IFIs. High-risk CMV serostatus (D-/R+) increased the risk of IFIs with a pooled odds ratio (OR) of 1.33 (1.04, 1.71), I² = 0%, but low-risk CMV serostatus (D-/R-) decreased the risk of IFIs with a pOR of 0.69 (0.55, 0.87), I² = 0%.

CONCLUSIONS

Post-transplant CMV infection and high-risk CMV serostatus increased the risk of IFIs, but low-risk CMV serostatus decreased risk of IFIs among allo-HSCT recipients. Further studies are needed to identify at-risk allo-HSCT recipients as well as to focus on fungal diagnostics and prophylaxis to prevent this fungal-after-viral phenomenon.

Cytomegalovirus reactivation is associated with an increased risk of late-onset invasive aspergillosis independently of grade II-IV acute graft-versus-host disease in allogeneic hematopoietic stem cell transplantation: JSTCT Transplant Complications Working Group

There is a matter of debate about the clinical impact of cytomegalovirus (CMV) reactivation on the development of late-onset invasive aspergillosis (IA), which occurs 40 days or later after allogeneic hematopoietic stem cell transplantation (HSCT). Using a Japanese transplant registry database, we analyzed the risk factors for the development of late-onset IA in 21,015 patients who underwent their first allogeneic HSCT between 2006 and 2017. CMV reactivation was defined as the initiation of preemptive anti-CMV antiviral therapy. Overall, there were 582 cases of late-onset IA, which occurred at a median of 95 days after HSCT. The 2-year cumulative incidence was 3.4% (95% confidence interval (CI), 3.0-3.9) in patients with CMV reactivation within 40 days after HSCT and 2.5% (95% CI, 2.3-2.8) in those without it (P < 0.001). In a multivariate analysis, CMV reactivation as a time-dependent covariate was significantly associated with the development of late-onset IA (hazard ratio (HR) 1.40, P < 0.001), as well as grade II-IV acute GVHD, age > 50 and HCT-CI ≥ 3 in the entire cohort. If we focus on the subgroup without grade II-IV acute GVHD, which is generally an indication for systemic corticosteroid therapy (n = 12,622), CMV reactivation was still a significant factor for the development of late-onset IA (HR 1.37, P = 0.045) as well as age > 50 years, HCT-CI ≥ 3, and cord blood transplantation. In conclusion, CMV reactivation was associated with an increased risk of late-onset IA after allogeneic HSCT independently of acute GVHD. Close monitoring for late-onset IA is necessary for patients who develop CMV reactivation even without grade II-IV acute GVHD.

Experimental Models of Infectious Pulmonary Complications Following Hematopoietic Cell Transplantation

Pulmonary infections remain a major cause of morbidity and mortality in hematopoietic cell transplantation (HCT) recipients. The prevalence and type of infection changes over time and is influenced by the course of immune reconstitution post-transplant. The interaction between pathogens and host immune responses is complex in HCT settings, since the conditioning regimens create periods of neutropenia and immunosuppressive drugs are often needed to prevent graft rejection and limit graft-versus-host disease (GVHD). Experimental murine models of transplantation are valuable tools for dissecting the procedure-related alterations to innate and adaptive immunity. Here we review mouse models of post-HCT infectious pulmonary complications, primarily focused on three groups of pathogens that frequently infect HCT recipients: bacteria (often P. aeruginosa), fungus (primarily Aspergillus fumigatus), and viruses (primarily herpesviruses). These mouse models have advanced our knowledge regarding how the conditioning and HCT process negatively impacts innate immunity and have provided new potential strategies of managing the infections. Studies using mouse models have also validated clinical observations suggesting that prior or occult infections are a potential etiology of noninfectious pulmonary complications post-HCT as well.

Aspergillus terreus Species Complex

Infections due to Aspergillus species are an acute threat to human health; members of the Aspergillus section Fumigati are the most frequently occurring agents, but depending on the local epidemiology, representatives of section Terrei or section Flavi are the second or third most important. Aspergillus terreus species complex is of great interest, as it is usually amphotericin B resistant and displays notable differences in immune interactions in comparison to Aspergillus fumigatus. The latest epidemiological surveys show an increased incidence of A. terreus as well as an expanding clinical spectrum (chronic infections) and new groups of at-risk patients being affected. Hallmarks of these non-Aspergillus fumigatus invasive mold infections are high potential for tissue invasion, dissemination, and possible morbidity due to mycotoxin production. We seek to review the microbiology, epidemiology, and pathogenesis of A. terreus species complex, address clinical characteristics, and highlight the underlying mechanisms of amphotericin B resistance. Selected topics will contrast key elements of A. terreus with A. fumigatus. We provide a comprehensive resource for clinicians dealing with fungal infections and researchers working on A. terreus pathogenesis, aiming to bridge the emerging translational knowledge and future therapeutic challenges on this opportunistic pathogen.

Severe Fever with Thrombocytopenia Syndrome Accompanied by Invasive Pulmonary Aspergillosis: An Autopsy Case

Severe fever with thrombocytopenia syndrome (SFTS) is an emerging tickborne infectious disease in China, Korea, and Japan caused by the SFTS virus (SFTSV). SFTS has a high mortality rate due to multiorgan failure. Recently, there are several reports on SFTS patients with mycosis. Here, we report a middle-aged Japanese SFTS patient with invasive pulmonary aspergillosis (IPA) revealed by an autopsy. A 61-year-old man with hypertension working in forestry was bitten by a tick and developed fever, diarrhea, and anorexia in 2 days. On day 4, consciousness disorder was appearing, and the patient was transferred to the University of Miyazaki Hospital. A blood test showed leukocytopenia, thrombocytopenia, as well as elevated levels of alanine aminotransferase, aspartate aminotransferase, lactate dehydrogenase, and creatine kinase. The SFTSV gene was detected in serum using a reverse-transcription polymerase chain reaction. On day 5, respiratory failure appeared and progressed rapidly, and on day 7, the patient died. An autopsy was performed that revealed hemophagocytosis in the bone marrow and bleeding of several organs. IPA was observed in lung specimens. SFTSV infection may be a risk factor for developing IPA. Early diagnosis and treatment of IPA may be important in patients with SFTS.

How we can mitigate the side effects associated with systemic glucocorticoid after allogeneic hematopoietic cell transplantation

Allogeneic hematopoietic cell transplantation (allo-HCT) is a potentially curative treatment for patients with a hematologic disease. Although the clinical outcomes after allo-HCT have significantly improved during the last few decades, graft-versus-host disease (GVHD) is still a major cause of post-HCT morbidity and mortality. Systemic glucocorticoids (GC) remain an integral part of treatment in patients with GVHD including both acute and chronic GVHD. Although it is well-known that usage of systemic GC is associated with various side effects, the short- and long-term effects of GCs in the HCT setting are not well-characterized due to limited published data. In order to clarify this issue, we summarize the information on side effects associated with GCs, focusing specifically on the sequelae of these agents in the early post-HCT period. In instances where limited data are available, we included data from other fields such as autoimmune diseases, given the potential parallels between autoimmune conditions and GVHD.

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.

Evaluation of a primary antifungal prophylaxis protocol for preventing invasive mold infections after allogeneic hematopoietic stem cell transplantation

INTRODUCTION

Invasive mold infections contribute to morbidity and mortality in patients undergoing allogeneic hematopoietic stem cell transplantation. The optimal strategy for primary antifungal prophylaxis in this patient population remains uncertain.

METHODS

Medical records of patients who underwent allogeneic hematopoietic stem cell transplantation between 1 January 2013 and 31 December 2017 were retrospectively reviewed. Adult patients were included if they received micafungin followed by fluconazole, with the option to escalate to voriconazole, for antifungal prophylaxis. The primary outcome was the incidence rate of proven or probable invasive mold infection. Secondary outcomes were time to invasive mold infection diagnosis, invasive mold infection-related mortality, and risk factors associated with invasive mold infection.

RESULTS

Two hundred patients were included in the study, a majority of whom underwent matched unrelated (46%) or matched related (33%) donor transplants. The incidence rate of proven or probable invasive mold infection was 18.4 cases per 100 patient-years, with a one-year cumulative incidence of 14%. Median time to proven or probable invasive mold infection was 94 days post-transplant (IQR 26-178), with invasive mold infection-related mortality occurring in 18 (64%) of 28 patients diagnosed with invasive mold infection. Comparison of invasive mold infection-free survival by potential risk factors failed to show any significant differences.

CONCLUSIONS

In this real-life cohort of allogeneic hematopoietic stem cell transplantation recipients, the incidence of proven or probable invasive mold infection was higher than expected based on previous literature. In the absence of standard guidance on anti-mold prophylaxis in this patient population and given that unique risk factors for invasive mold infection may differ between institutions, it is essential that centers performing allogeneic hematopoietic stem cell transplantation routinely monitor their antifungal prophylaxis strategies for effectiveness.

Invasive Mold Infections After Chimeric Antigen Receptor-Modified T-Cell Therapy: A Case Series, Review of the Literature, and Implications for Prophylaxis

Data on invasive mold infections (IMIs) after chimeric antigen receptor-modified T-cell (CAR-T-cell) therapy are limited. We describe 2 patients with post-CAR-T-cell IMI (Fusarium, Mucorales) and review the published literature. We propose strategies to prevent IMIs in patients, based on the IMI rate and presence of neutropenia or steroid use.

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.

Baseline Chest Computed Tomography as Standard of Care in High-Risk Hematology Patients

Baseline chest computed tomography (BCT) in high-risk hematology patients allows for the early diagnosis of invasive pulmonary aspergillosis (IPA). The distribution of BCT implementation in hematology departments and impact on outcome is unknown. A web-based questionnaire was designed. International scientific bodies were invited. The estimated numbers of annually treated hematology patients, chest imaging timepoints and techniques, IPA rates, and follow-up imaging were assessed. In total, 142 physicians from 43 countries participated. The specialties included infectious diseases (n = 69; 49%), hematology (n = 68; 48%), and others (n = 41; 29%). BCT was performed in 57% (n = 54) of 92 hospitals. Upon the diagnosis of malignancy or admission, 48% and 24% performed BCT, respectively, and X-ray was performed in 48% and 69%, respectively. BCT was more often used in hematopoietic cell transplantation and in relapsed acute leukemia. European centers performed BCT in 59% and non-European centers in 53%. Median estimated IPA rate was 8% and did not differ between BCT (9%; IQR 5–15%) and non-BCT centers (7%; IQR 5–10%) (p = 0.69). Follow-up computed tomography (CT) for IPA was performed in 98% (n = 90) of centers. In high-risk hematology patients, baseline CT is becoming a standard-of-care. Chest X-ray, while inferior, is still widely used. Randomized, controlled trials are needed to investigate the impact of BCT on patient outcome.

D-Index-Guided Early Antifungal Therapy Versus Empiric Antifungal Therapy for Persistent Febrile Neutropenia: A Randomized Controlled Noninferiority Trial

PURPOSE

Empiric antifungal therapy (EAT) is recommended for persistent febrile neutropenia (FN), but in most patients, it is associated with overtreatment. The D-index, calculated as the area surrounded by the neutrophil curve and the horizontal line at a neutrophil count of 500/μL, reflects both the duration and depth of neutropenia and enables real-time monitoring of the risk of invasive fungal infection in individual patients at no cost. We investigated a novel approach for patients with persistent FN called D-index-guided early antifungal therapy (DET), in which antifungal treatment is postponed until a D-index reaches 5,500 or the detection of positive serum or imaging tests, and compared it with EAT in this multicenter open-label noninferiority randomized controlled trial.

PATIENTS AND METHODS

We randomly assigned 423 patients who underwent chemotherapy or hematopoietic stem-cell transplantation for hematologic malignancies to the EAT or DET group. The prophylactic use of antifungal agents other than polyenes, echinocandins, or voriconazole was allowed. Micafungin at 150 mg per day was administered as EAT or DET.

RESULTS

In an intent-to-treat analysis of 413 patients, the incidence of probable/proven invasive fungal infection was 2.5% in the EAT group and 0.5% in the DET group, which fulfilled the predetermined criterion of noninferiority of the DET group (-2.0%; 90% CI, -4.0% to 0.1%). The survival rate was 98.0% versus 98.6% at day 42 and 96.4% versus 96.2% at day 84. The use of micafungin was significantly reduced in the DET group (60.2% v 32.5%; P < .001).

CONCLUSION

A novel strategy, DET, decreased the use and cost of antifungal agents without increasing invasive fungal infections and can be a reasonable alternative to empiric or preemptive antifungal therapy.

Seasonal changes in indoor airborne fungal concentration in a hematology ward

Invasive fungal disease (IFD) is an important infectious complication of hematological disorders, especially in hematopoietic stem cell transplantation recipients. Evidences suggest seasonal and/or geographical variations in the airborne fungal counts and a relationship between those counts and the incidence of IFD. We evaluated the concentrations of indoor airborne fungi quantitated over the course of one year in a hematology ward in Japan. In January, April, July, and October, fixed volumes of air samples were obtained by an air sampler in a hematology ward not equipped with a high-efficiency particulate air filter and incubated in fugal cultures. Samples were also obtained from a protective environment in the same ward and were evaluated. The number of fungal colonies per 50 L of sampled air was highest in October (median 2.25 (range, 0.2-7.0)), which was significantly higher than those in the other three months (0.1 (range, 0-1.0) in January; 0 (0-0) in April; 0.55 (0-2.5) in July; P < 0.01)). Commonly identified pathogens included Penicillium and Cladosrporium species, but Aspergillus species was detected only in July and October samples. These results suggest a seasonal variation in indoor airborne fungal concentrations in Japan, which could affect the epidemiology of IFD.

A case of invasive pulmonary aspergillosis diagnosed by transbronchial lung biopsy during treatment for diabetic ketoacidosis in a type 1 diabetic patient

Invasive pulmonary aspergillosis (IPA) patients with non-hematological malignancy are far less than with hematological malignancy patients. We encountered a very rare case of IPA in which type 1 diabetes was the only conceivable risk factor. Further, according to the diagnostic categories of the European Organization for Research and Treatment of Cancer/Invasive Fungal Infections Cooperative Group and the National Institute of Allergy and Infectious Diseases Mycoses Study Group (EORTC/MSG) criteria for IPA, the frequency of proven diagnosis is very low. Here we report a proven IPA, which rapidly developed when the patient with type 1 diabetes was being treated for diabetic ketoacidosis, which was successfully treated with the combination therapy of voriconazole (VRCZ) and micafungin (MCFG), based on early diagnosis using bronchoscopy.

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.

Are there differences in risk factors, microbial aspects, and prognosis of cellulitis between compensated and decompensated hepatitis C virus-related cirrhosis?

Background/Aims

Cellulitis is a common infection in patients with liver cirrhosis. We aimed to compare risk factors, microbial aspects, and outcomes of cellulitis in compensated and decompensated hepatitis C virus (HCV)-related cirrhosis.

Methods

Six hundred twenty consecutive HCV-related cirrhotic patients were evaluated for cellulitis. Demographic and clinical data were evaluated, along with blood and skin cultures. Severity of cirrhosis was assessed using Child-Pugh score. In-hospital mortality was assessed.

Results

Seventy-seven (12.4%) cirrhotic patients had cellulitis (25 with compensated and 52 with decompensated disease). Smoking and venous insufficiency were risk factors of cellulitis in compensated cirrhosis. Leg edema, ascites, hyperbilrubinemia and hypoalbuminemia were risk factors in decompensated cirrhosis. Gram-positive bacteria (Staphylococcus spp. and Streptococcus pyogenes) were the infective organisms in compensated patients, while gram negative bacteria (Escherichia coli, Klebsiella pneumoniae, and Pseudomonas aeruginosa) were the predominant organisms in decompensated cirrhosis. Fungi (Candida albicans and Aspergillus niger) were detected in 3 decompensated cases. In-hospital mortality in patients with cellulitis was 27.3%, approaching 100% in decompensated patients with gram-negative cellulitis. Prolonged hospitalization, higher model for end-stage liver disease (MELD)-Na score, septic shock, local complication, and recurrent cellulitis were predictors of mortality.

Conclusions

Cellulitis in compensated cirrhosis is different from that of decompensated patients regarding microorganisms, pathogenesis, and prognosis. Cellulitis has a poor prognosis, with mortality rates approaching 100% in decompensated patients with gram-negative cellulitis. Stratifying patients according to severity of cirrhosis is important to identify the proper empirical antibiotic and to decide the proper means of care.

Complications of Stem Cell Transplantation that Affect Infections in Stem Cell Transplant Recipients, with Analogies to Patients with Hematologic Malignancies

This article discusses the complications of hematopoietic stem cell transplantion (HSCT) that affect infections in HSCT recipients, with analogies to patients with hematologic malignancies. Mucositis, with mucosal barrier disruption, is common and increases the risk of gram-positive and anaerobic bacterial, and fungal infections, and can evolve to typhlitis. Engraftment syndrome; graft-versus-host disease, hepatic sinusoidal obstruction syndrome; and posterior reversible encephalopathy syndrome can affect the infectious potential either directly from organ dysfunction or indirectly from specific treatment. Pulmonary infections can predispose to life threatening complications including diffuse alveolar hemorrhage, idiopathic pulmonary syndrome, bronchiolitis obliterans syndrome, and bronchiolitis obliterans with organizing pneumonia.

Host and Graft Factors Impacting Infection Risk in Hematopoietic Cell Transplantation

Infection contributes significantly to morbidity and mortality in hematopoietic cell transplantation. A complex interplay of host, graft, and technical factors contributes to infectious risk in the recipient. Host factors such as age, underlying disease, and comorbidities; central venous access; and the preparative regimen contribute to mucosal disruption, organ dysfunction, and immunodeficiency before hematopoietic cell transplantation. Graft factors, including donor histocompatibility, cell source, and graft components, along with immunosuppression and graft-versus-host disease, contribute to the speed of immune reconstitution. Evaluation of these factors, plus previous and posttransplant exposure to pathogens, is necessary to best assess an individual recipient's infection risk.

Impacts and Challenges of Advanced Diagnostic Assays for Transplant Infectious Diseases

The advanced technologies described in this chapter should allow for full inventories to be made of bacterial genes, their time- and place-dependent expression, and the resulting proteins as well as their outcome metabolites. The evolution of these molecular technologies will continue, not only in the microbial pathogens but also in the context of host-pathogen interactions targeting human genomics and transcriptomics. Their performance characteristics and limitations must be clearly understood by both laboratory personnel and clinicians to ensure proper utilization and interpretation.

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.

Infections in Allogeneic Stem Cell Transplantation

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) has become a widely used modality of therapy for a variety of malignant and nonmalignant diseases. Despite advances in pharmacotherapy and transplantation techniques, infection remains one of the most severe and frequently encountered complications of allo-HSCT.

This chapter will address the risk factors for development of infection following allo-HSCT, including those related to the host, the conditioning regimen, and the graft, as well as the timing of opportunistic infections after allo-HSCT. The most common bacterial, viral, fungal, and parasitic infections, as well as issues surrounding their diagnostics and treatment, will be discussed. Finally, this chapter will address vaccination and other preventative strategies to be utilized when caring for patients undergoing allo-HSCT.

Incidence and outcome of invasive fungal diseases after allogeneic hematopoietic stem cell transplantation: A Swiss transplant cohort study

Contemporary, comprehensive data on epidemiology and outcomes of invasive fungal disease (IFD) including breakthrough IFD among allogeneic hematopoietic stem cell transplantation (HSCT) recipients are scarce. We included 479 allogeneic HSCT recipients with 10 invasive candidiasis (IC) and 31 probable/proven invasive mold disease (IMD) from the Swiss Transplant Cohort Study from 01.2009 to 08.2013. Overall cumulative incidence was 2.3% for IC and 8.5% for probable/proven IMI: 6% for invasive aspergillosis (IA) and 2.5% for non-AspergillusIMI. Among 41 IFD, 46% IFD were breakthrough, with an overall incidence of 4.6%, more frequently caused by other-than-Aspergillus fumigatus molds than primary IFD (47.6% (10/21) vs 13% (3/23), P = 0.04). Twelve-week mortality among patients with IC was 20% and 58.6% for probable/proven IMD (60% IA and 54.6% non-Aspergillus). Our results reveal that breakthrough IFD represent a marked burden of probable/proven IFD postallogeneic HSCT and mortality remains above 50% in patients with probable/proven IMD, underscoring the ongoing challenges to prevent and treat IFD in these patients.

Efficacy of Caspofungin in Unclassified Invasive Fungal Infection Cases: A Retrospective Analysis of Patients with Hematological Malignancies in China

Background

The management of invasive fungal infection (IFI) is challenging in immunocompromised patients who do not fully satisfy the EORTC/MSG diagnostic criteria of proven or probable IFI. Our study assessed caspofungin efficacy in 582 Chinese patients with hematological malignancies exhibiting unclassified signs or symptoms of IFI.

Material/Methods

This retrospective study included caspofungin treatment outcomes of an unclassified group A (n=401) of patients without microbiological or biomarker results and group B (n=181) patients with positive microbiological or biomarker results. Factors that correlated with clinical outcomes were determined using univariate and multivariate analyses.

Results

Cough (41.8%), expectoration (29.6%), and chest tightness (14.6%) were the most common clinical features, and changes in CT images (88.1%) were more frequently detected than in X-ray images (19.6%) in all patients. Favorable response rates for caspofungin as first-line treatment were 58.2% for group A and 56.3% for group B. Eastern Cooperative Oncology Group (ECOG) score, cardiovascular disease, hemoptysis, and absolute neutrophil count (ANC) <1000/mm³ before antifungal treatment without recovery were associated with unfavorable clinical outcome (P<0.05 for all). Cough and ANC recovery >1000/mm³ were significantly associated with favorable (complete or partial resolution) outcome.

Conclusions

Caspofungin was effective for treating unclassified IFIs of immunocompromised patients. Cardiovascular disease, ECOG score, cough, and/or hemoptysis, as well as ANC count, represent a potential index for estimating response of unclassified IFI patients to caspofungin treatments.

Diagnosis and management of Aspergillus diseases: executive summary of the 2017 ESCMID-ECMM-ERS guideline

The European Society for Clinical Microbiology and Infectious Diseases, the European Confederation of Medical Mycology and the European Respiratory Society Joint Clinical Guidelines focus on diagnosis and management of aspergillosis. Of the numerous recommendations, a few are summarized here. Chest computed tomography as well as bronchoscopy with bronchoalveolar lavage (BAL) in patients with suspicion of pulmonary invasive aspergillosis (IA) are strongly recommended. For diagnosis, direct microscopy, preferably using optical brighteners, histopathology and culture are strongly recommended. Serum and BAL galactomannan measures are recommended as markers for the diagnosis of IA. PCR should be considered in conjunction with other diagnostic tests. Pathogen identification to species complex level is strongly recommended for all clinically relevant Aspergillus isolates; antifungal susceptibility testing should be performed in patients with invasive disease in regions with resistance found in contemporary surveillance programmes. Isavuconazole and voriconazole are the preferred agents for first-line treatment of pulmonary IA, whereas liposomal amphotericin B is moderately supported. Combinations of antifungals as primary treatment options are not recommended. Therapeutic drug monitoring is strongly recommended for patients receiving posaconazole suspension or any form of voriconazole for IA treatment, and in refractory disease, where a personalized approach considering reversal of predisposing factors, switching drug class and surgical intervention is also strongly recommended. Primary prophylaxis with posaconazole is strongly recommended in patients with acute myelogenous leukaemia or myelodysplastic syndrome receiving induction chemotherapy. Secondary prophylaxis is strongly recommended in high-risk patients. We strongly recommend treatment duration based on clinical improvement, degree of immunosuppression and response on imaging.

Novel fluconazole derivatives with promising antifungal activity

The fungistatic nature and toxicity concern associated with the azole drugs currently on the market have resulted in an increased demand for new azole antifungal agents for which these problematic characteristics do not exist. The extensive use of azoles has resulted in fungal strains capable of resisting the action of these drugs. Herein, we report the synthesis and antifungal activity of novel fluconazole (FLC) analogues with alkyl-, aryl-, cycloalkyl-, and dialkyl-amino substituents. We evaluated their antifungal activity by MIC determination and time-kill assay as well as their safety profile by hemolytic activity against murine erythrocytes as well as cytotoxicity against mammalian cells. The best compounds from our study exhibited broad-spectrum activity against most of the fungal strains tested, with excellent MIC values against a number of clinical isolates. The most promising compounds were found to be less hemolytic than the least hemolytic FDA-approved azole antifungal agent voriconazole (VOR). Finally, we demonstrated that the synthetic alkyl-amino FLC analogues displayed chain-dependent fungal membrane disruption as well as inhibition of ergosterol biosynthesis as possible mechanisms of action.

Differential Kinetics of Aspergillus nidulans and Aspergillus fumigatus Phagocytosis

Invasive aspergillosis mainly occurs in immunocompromised patients and is commonly caused by Aspergillus fumigatus, while A.nidulans is rarely the causative agent. However, in chronic granulomatous disease (CGD) patients, A. nidulans is a frequent cause of invasive aspergillosis and is associated with higher mortality. Immune recognition of A. nidulans was compared to A. fumigatus to offer an insight into why A. nidulans infections are prevalent in CGD. Live cell imaging with J774A.1 macrophage-like cells and LC3-GFP-mCherry bone marrow-derived macrophages (BMDMs) revealed that phagocytosis of A. nidulans was slower compared to A. fumigatus. This difference could be attributed to slower migration of J774A.1 cells and a lower percentage of migrating BMDMs. In addition, delayed phagosome acidification and LC3-associated phagocytosis was observed with A. nidulans. Cytokine and oxidative burst measurements in human peripheral blood mononuclear cells revealed a lower oxidative burst upon challenge with A. nidulans. In contrast, A. nidulans induced significantly higher concentrations of cytokines. Collectively, our data demonstrate that A. nidulans is phagocytosed and processed at a slower rate compared to A. fumigatus, resulting in reduced fungal killing and increased germination of conidia. This slower rate of A. nidulans clearance may be permissive for overgrowth within certain immune settings.

Design, Synthesis, Antifungal Activity and Molecular Docking of Thiochroman-4-one Derivatives

N-Myristoyltransferase (NMT) has been validated pre-clinically as a target for treatment of fungal infections. Various substituted thiochroman-4-one derivatives have been synthesized by an efficient method. The synthesized compounds 7a-y and 8a-t were evaluated for their in vitro antifungal activity against the Canidia albicans, Cryptococcus neoformans, Epidermophyton floccosum, Mucor racemosus, Microsporum gypseum and Aspergillus nigerstrain. A series of compounds exhibited significant activity (minimal inhibitory concentrotion (MIC)=0.5-16 µg/mL) against Canidia albicans and Cryptococcus neoformans. The antifungal activity of compound 7b was reached to that of fluconazole, which can serve as a good starting point for further studies of structural diversity of the NMT inhibitors. The molecular docking studies revealed an interesting binding profile with very high receptor affinity for NMT of Canidia albicans.

Central nervous system complications after allogeneic hematopoietic stem cell transplantation

Allogenic hematopoietic stem cell transplant (alloSCT) is a potentially curative modality of treatment for patients with hematological malignancies. However, CNS complications following transplant pose a risk to survival of the patients. Early recognition and management of these complications are crucial to reduce morbidity and mortality of patients following transplant. Early CNS complications associated with alloSCT are infection, cerebrovascular events, chemotherapy and radiation-induced toxicities while late complications include post-transplant lymphoproliferative disorder, CNS relapse of underlying malignancy and viral and fungal infections. Development of graft-versus-host disease can further increase the risk of CNS complications and outcomes after alloSCT. Strategies aimed to reduce the risk of CNS complications and early management may ameliorate the morbidity and mortality in transplant recipients.

Posaconazole-Loaded Leukocytes as a Novel Treatment Strategy Targeting Invasive Pulmonary Aspergillosis

Background

Impaired delivery of antifungals to hyphae within necrotic lesions is thought to contribute to therapeutic failure in invasive pulmonary aspergillosis (IPA). We hypothesized that transfusion of leukocytes loaded ex vivo with the lipophilic antifungal posaconazole could improve delivery of antifungals to the sites of established infection and improve outcome in experimental IPA.

Methods

The HL-60 leukemia cell line was differentiated to a neutrophil-like phenotype (differentiated HL-60 [dHL-60] cells) and then exposed to a range of posaconazole concentrations. The functional capacity and antifungal activity of these cells were assessed in vitro and in a mouse model of IPA.

Results

Posaconazole levels in dHL-60 cells were 265-fold greater than the exposure concentration. Posaconazole-loaded cells were viable and maintained their capacity to undergo active chemotaxis. Contact-dependent transfer of posaconazole from dHL-60 cells to hyphae was observed in vitro, resulting in decreased fungal viability. In a neutropenic mouse model of IPA, treatment with posaconazole-loaded dHL-60 cells resulted in significantly reduced fungal burden in comparison to treatment with dHL-60 cells alone.

Conclusions

Posaconazole accumulates at high concentrations in dHL-60 cells and increases their antifungal activity in vitro and in vivo. These findings suggest that posaconazole-loading of leukocytes may hold promise for the therapy of IPA.

Multicenter Evaluation of Risk Factors for Aspergillosis in Patients Treated with Lipid Amphotericin B Products: Outcomes, Drug Utilization Parameters, and Benchmarking

Purpose

To evaluate the use of lipid amphotericin B products in relation to risk factors for aspergillosis and candidemia at the time therapy was initiated.

Methods

A single-group, concurrent, observational, multicenter study in hospitalized patients receiving a lipid amphotericin B product (Abelcet or AmBisome) was undertaken. The severity of illness, duration of therapy, length of hospital stay, microbiology, all-cause mortality, physician specialty, and clinical characteristics of each patient was recorded. Risk factors for aspergillosis and candidemia and process markers that might identify patients as candidates for lipid amphotericin B therapy were collected.

Results

One hundred eighty-six patients were enrolled in six US medical centers. One hundred four patients had positive fungal cultures; the majority of positive cultures were for Candida albicans (n = 40) or yeast (n = 27). Sixteen patients had positive cultures for Aspergillus. All patients receiving a lipid amphotericin B product had an overall statistically significantly greater number of risk factors for Candida vs Aspergillus infection. The mean (± SD) number of risk factors for Aspergillus was 2.46 ± 1.97 (range 0–10) and for Candida was 7.77 ± 3.14 (range 1–16) (P < 0.05). Risk factor assessment by medical service showed a statistically significantly larger number of Aspergillus risk factors in the bone marrow transplant (BMT) service compared with all other services (P < 0.05).

Conclusions

There were fewer documented risk factors for aspergillosis than candidemia in patients receiving a lipid amphotericin B product. Establishing drug usage protocols that include culture analysis, risk factor identification, high-risk medical services, and incorporation of drug use evaluation measures can guide the practitioner in selecting the appropriate therapy for their patients.

Sepsis and Challenging Infections in the Immunosuppressed Patient in the Intensive Care Unit

In 2017, most intensive care units (ICUs) worldwide are admitting a growing population of immunosuppressed patients. The most common causes of pre-ICU immunosuppression are solid organ transplantation, hematopoietic stem cell transplantation, and infection due to human immunodeficiency virus. In this article, the authors review the most frequent infections that cause critical care illness in each of these 3 immunosuppressed patient populations.