Ivosidenib significantly reduces triazole levels in patients with acute myeloid leukemia and myelodysplastic syndrome

BACKGROUND

Ivosidenib is primarily metabolized by CYP3A4; however, it induces CYP450 isozymes, including CYP3A4 and CYP2C9, whereas it inhibits drug transporters, including P-glycoprotein. Patients with acute myeloid leukemia are at risk of invasive fungal infections, and therefore posaconazole and voriconazole are commonly used in this population. Voriconazole is a substrate of CYP2C9, CYP2C19, and CYP3A4; therefore, concomitant ivosidenib may result in decreased serum concentrations. Although posaconazole is a substrate of P-glycoprotein, it is metabolized primarily via UDP glucuronidation; thus, the impact of ivosidenib on posaconazole exposure is unknown.

METHODS

Patients treated with ivosidenib and concomitant triazole with at least one serum trough level were included. Subtherapeutic levels were defined as posaconazole <700 ng/mL and voriconazole <1.0 µg/mL. The incidences of breakthrough invasive fungal infections and QTc prolongation were identified at least 5 days after initiation of ivosidenib with concomitant triazole.

RESULTS

Seventy-eight serum triazole levels from 31 patients receiving ivosidenib-containing therapy and concomitant triazole were evaluated. Of the 78 concomitant levels, 47 (60%) were subtherapeutic (posaconazole: n = 20 of 43 [47%]; voriconazole: n = 27 of 35 [77%]). Compared to levels drawn while patients were off ivosidenib, median triazole serum levels during concomitant ivosidenib were significantly reduced. There was no apparent increase in incidence of grade 3 QTc prolongation with concomitant azole antifungal and ivosidenib 500 mg daily.

CONCLUSIONS

This study demonstrated that concomitant ivosidenib significantly reduced posaconazole and voriconazole levels. Voriconazole should be avoided, empiric high-dose posaconazole (>300 mg/day) may be considered, and therapeutic drug monitoring is recommended in all patients receiving concomitant ivosidenib.

The modern face of esophageal candidiasis in an oncology center: Correlating clinical manifestations, endoscopic grade, and pathological data in 323 contemporary cancer patients

OBJECTIVES

Clinical presentation and outcomes of esophageal candidiasis (EC) in cancer patients are scarcely studied in the azole era, as is the correlation between clinical, endoscopic, and histopathological EC manifestations.

METHODS

We retrospectively reviewed the risk factors, clinical features, and outcomes of pathology-documented EC cases at MD Anderson Cancer Center. We further assessed associations between presence of symptoms, standardized 4-stage endoscopic grade (Kodsi classification), histopathological data, and fluconazole treatment failure.

RESULTS

Among 323 cancer patients with EC, 89% had solid tumors, most commonly esophageal cancer (29%). Thirty-three percent of EC patients were asymptomatic. The proportion of symptomatic EC patients significantly increased with endoscopic grade (P = 0.005). Among 202 patients receiving oral fluconazole, 27 (13%) had treatment failure. Underlying esophageal disease was the only independent predictor of fluconazole treatment failure (odds ratio: 3.88, P = 0.005). Endoscopic grade correlated significantly with Candida organism burden (Correlation coefficient [ρ] = 0.21, P < 0.01) and neutrophilic inflammation (ρ = 0.18, P < 0.01). Candida invasion of the squamous mucosal layer was associated with treatment failure (P = 0.049).

CONCLUSIONS

EC was predominantly encountered in patients with solid tumors. One-third of EC patients were asymptomatic, challenging traditional symptom-based diagnosis. The development of integrated clinicopathological scoring systems could further guide the therapeutic management of cancer patients with EC.

A novel lentiviral vector-based approach to generate chimeric antigen receptor T cells targeting Aspergillus fumigatus

Invasive aspergillosis (IA) is a common and deadly mold infection in immunocompromised patients. As morbidity and mortality of IA are primarily driven by poor immune defense, adjunct immunotherapies, such as chimeric antigen receptor (CAR) T cells, are direly needed. Here, we propose a novel approach to generate Aspergillus fumigatus (AF)-CAR T cells using the single-chain variable fragment domain of monoclonal antibody AF-269-5 and a lentiviral vector system. These cells successfully targeted mature hyphal filaments of representative clinical and reference AF isolates and elicited a potent release of cytotoxic effectors and type 1 T cell cytokines. Furthermore, AF-CAR T cells generated from peripheral blood mononuclear cells of four healthy human donors and expanded with either of three cytokine stimulation regimens (IL-2, IL-2 + IL-21, or IL-7 + IL-15) significantly suppressed mycelial growth of AF-293 after 18 hours of co-culture and synergized with the immunomodulatory antifungal agent caspofungin to control hyphal growth for 36 hours. Moreover, cyclophosphamide-immunosuppressed NSG mice with invasive pulmonary aspergillosis that received two doses of 5 million AF-CAR T cells (6 and 48 hours after AF infection) showed significantly reduced morbidity on day 4 post-infection (P < 0.001) and significantly improved 7-day survival (P = 0.049) compared with mice receiving non-targeting control T cells, even without concomitant antifungal chemotherapy. In conclusion, we developed a novel lentiviral strategy to obtain AF-CAR T cells with high targeting efficacy, yielding significant anti-AF activity in vitro and short-term protection in vivo. Our approach could serve as an important steppingstone for future clinical translation of antifungal CAR T-cell therapy after further refinement and thorough preclinical evaluation.IMPORTANCEInvasive aspergillosis (IA) remains a formidable cause of morbidity and mortality in patients with hematologic malignancies and those undergoing hematopoietic stem cell transplantation. Despite the introduction of several new Aspergillus-active antifungals over the last 30 years, the persisting high mortality of IA in the setting of continuous and profound immunosuppression is a painful reminder of the major unmet need of effective antifungal immune enhancement therapies. The success of chimeric antigen receptor (CAR) T-cell therapy in cancer medicine has inspired researchers to translate this approach to opportunistic infections, including IA. Aiming to refine anti-Aspergillus CAR T-cell therapy and improve its feasibility for future clinical translation, we herein developed and validated a novel antibody-based CAR construct and lentiviral transduction method to accelerate the production of CAR T cells with high targeting efficacy against Aspergillus fumigatus. Our unique approach could provide a promising platform for future clinical translation of CAR T-cell-based antifungal immunotherapy.

PCR diagnostic platforms for non-Aspergillus mold infections: ready for routine implementation in the clinic?

INTRODUCTION

While Aspergillus spp. remain the predominant cause of invasive mold infections, non-Aspergillus molds, such as the Mucorales or Fusarium spp., account for an increasing proportion of cases. The diagnosis of non-Aspergillus invasive mold infections (NAIMI) is challenging because of the low sensitivity and delay of conventional microbiological tests. Therefore, there is a particular interest to develop molecular tools for their early detection in blood or other clinical samples.

AREAS COVERED

This extensive review of the literature discusses the performance of Mucorales-specific PCR and other genus-specific or broad-range fungal PCR that can be used for the diagnosis of NAIMI in diverse clinical samples, with a focus on novel technologies.

EXPERT OPINION

PCR currently represents the most promising approach, combining good sensitivity/specificity and ability to detect NAIMI in clinical samples before diagnosis by conventional cultures and histopathology. Several PCR assays have been designed for the detection of Mucorales in particular, but also Fusarium spp. or Scedosporium/Lomentospora spp. Some commercial Mucorales PCRs are now available. While efforts are still needed for standardized protocols and the development of more rapid and simpler techniques, PCR is on the way to becoming an essential test for the early diagnosis of mucormycosis and possibly other NAIMIs.

Anorectal Infections in Neutropenic Leukemia Patients: A Common Clinical Challenge

Anorectal infections in neutropenic leukemia patients are a significant and potentially life-threatening complication. The pathogenesis of this condition is not entirely understood and believed to be multifactorial, including mucosal injury as a result of cytotoxic drugs, profound neutropenia and impaired host defense. Establishing an early diagnosis is key and often made clinically on the basis of signs and symptoms, but also from imaging studies demonstrating perianal inflammation or fluid collection. The management of anorectal infections in neutropenic leukemia patients is not straightforward, as there are no well-conducted studies on this entity. This review seeks to provide a framework into the pathophysiology and clinical presentation of anorectal infections in neutropenic leukemia patients, propose a diagnostic approach and to discuss controversies in the management of this condition.

Disseminated Histoplasmosis in a Patient with Myelofibrosis on Ruxolitinib: A Case Report and Review of the Literature on Ruxolitinib-Associated Invasive Fungal Infections

Ruxolitinib, a selective inhibitor of Janus kinases, is a standard treatment for intermediate/high-risk myelofibrosis (MF) but is associated with a predisposition to opportunistic infections, especially herpes zoster. However, the incidence and characteristics of invasive fungal infections (IFIs) in these patients remain uncertain. In this report, we present the case of a 59-year-old woman with MF who developed disseminated histoplasmosis after seven months of ruxolitinib use. The patient clinically improved after ten weeks of combined amphotericin B and azole therapy, and ruxolitinib was discontinued. Later, the patient received fedratinib, a relatively JAK2-selective inhibitor, without relapse of histoplasmosis. We also reviewed the literature on published cases of proven IFIs in patients with MF who received ruxolitinib. Including ours, we identified 28 such cases, most commonly due to Cryptococcus species (46%). IFIs were most commonly disseminated (39%), followed by localized lung (21%) infections. Although uncommon, a high index of suspicion for opportunistic IFIs is needed in patients receiving JAK inhibitors. Furthermore, the paucity of data regarding the optimal management of IFIs in patients treated with JAK inhibitors underscore the need for well-designed studies to evaluate the epidemiology, pathobiology, early diagnosis, and multimodal therapy of IFIs in patients with hematological malignancies receiving targeted therapies.

Impact of climate change and natural disasters on fungal infections

The effects of climate change and natural disasters on fungal pathogens and the risks for fungal diseases remain incompletely understood. In this literature review, we examined how fungi are adapting to an increase in the Earth's temperature and are becoming more thermotolerant, which is enhancing fungal fitness and virulence. Climate change is creating conditions conducive to the emergence of new fungal pathogens and is priming fungi to adapt to previously inhospitable environments, such as polluted habitats and urban areas, leading to the geographical spread of some fungi to traditionally non-endemic areas. Climate change is also contributing to increases in the frequency and severity of natural disasters, which can trigger outbreaks of fungal diseases and increase the spread of fungal pathogens. The populations mostly affected are the socially vulnerable. More awareness, research, funding, and policies on the part of key stakeholders are needed to mitigate the effects of climate change and disaster-related fungal diseases.

Invasive fusariosis in patients with leukaemia in the era of mould-active azoles: increasing incidence, frequent breakthrough infections and lack of improved outcomes

OBJECTIVES

Historically, patients with leukaemia and invasive fusariosis (IF) have experienced poor outcomes in the setting of persistent immunosuppression. Herein, we retrospectively reviewed the incidence, presentation and outcomes of IF that are scarcely studied in contemporary cohorts of leukaemia patients.

METHODS

We identified adult leukaemia patients with proven or probable IF at MD Anderson Cancer Center during 2009-21. Independent risk factors for 42 day mortality after IF diagnosis were determined using a multivariable logistic regression model. Combined with historical data, the annual IF incidence density over the past 23 years was estimated using Poisson regression analysis.

RESULTS

Among 140 leukaemia patients with IF (114 proven), 118 patients (84%) had relapsed/refractory leukaemia and 124 (89%) had neutropenia at IF diagnosis. One hundred patients (71%) had pulmonary IF, 88 (63%) had disseminated IF and 48 (34%) had fungaemia. Coinfections were common (55%). Eighty-nine patients (64%) had breakthrough IF to mould-active triazoles. Most patients (84%) received combination antifungal therapy. Neutrophil recovery [adjusted OR (aOR), 0.04; 95% CI, 0.01-0.14; P < 0.0001], pulmonary IF (aOR, 3.28; 95% CI, 1.11-9.70; P = 0.032) and high SOFA score (aOR, 1.91 per 1-point increase; 95% CI, 1.47-2.50; P < 0.0001) were independent predictors of 42 day mortality outcomes. From 1998 to 2021, IF incidence density increased significantly at an annual ratio of 1.03 (95% CI, 1.01-1.06; P = 0.04).

CONCLUSIONS

IF is predominantly seen in patients with relapsed/refractory leukaemia and increasingly seen as a breakthrough infection to mould-active triazoles. Despite frequent combination antifungal therapy, high mortality rates have persisted in patients with lasting neutropenia.

Co-Occurrence of Gram-Negative Rods in Patients with Hematologic Malignancy and Sinopulmonary Mucormycosis

Both Mucorales and Gram-negative rods (GNRs) commonly infect patients with hematological malignancies (HM); however, their co-occurrence is understudied. Therefore, we retrospectively reviewed the records of 63 patients with HM and proven or probable sinopulmonary mucormycosis at MD Anderson Cancer Center (Houston, Texas) from 2000-2020. Seventeen out of sixty-three reviewed patients (27.0%) had sinopulmonary co-occurrence of GNRs (most commonly Pseudomonas aeruginosa and Stenotrophomonas maltophilia) within 30 days of a positive Mucorales culture or histology demonstrating Mucorales species. Eight of seventeen co-isolations of Mucorales and GNRs were found in same-day samples. All 15 patients with GNR co-occurrence and reported antimicrobial data had received anti-Pseudomonal agents within 14 days prior to diagnosis of mucormycosis and 5/15 (33.3%) had received anti-Stenotrophomonal agents. Demographic and clinical characteristics of patients with and without GNR co-occurrence were comparable. Forty-two-day all-cause mortality was high (34.9%) and comparable in patients with (41.2%) and without (32.6%) GNR detection (p = 0.53). In summary, over a quarter of heavily immunosuppressed patients with sinopulmonary mucormycosis harbored GNRs in their respiratory tract. Although no impact on survival outcomes was seen in a background of high mortality in our relatively underpowered study, pathogenesis studies are needed to understand the mutualistic interplay of GNR and Mucorales and their influence on host responses.

Social determinants of health as drivers of fungal disease

Disparities in social determinants of health (SDOH) play a significant role in causing health inequities globally. The physical environment, including housing and workplace environment, can increase the prevalence and spread of fungal infections. A number of professions are associated with increased fungal infection risk and are associated with low pay, which may be linked to crowded and sub-optimal living conditions, exposure to fungal organisms, lack of access to quality health care, and risk for fungal infection. Those involved and displaced from areas of armed conflict have an increased risk of invasive fungal infections. Lastly, a number of fungal plant pathogens already threaten food security, which will become more problematic with global climate change. Taken together, disparities in SDOH are associated with increased risk for contracting fungal infections. More emphasis needs to be placed on systematic approaches to better understand the impact and reducing the health inequities associated with these disparities.

Invasive mucorales sinusitis in a young patient with Emberger syndrome and newly diagnosed AML: A case report and literature review of invasive fungal infections in GATA2 deficiency

Germline pathogenic variants (PVs) in the gene encoding the GATA2 transcription factor can result in profound reductions of monocytes, dendritic cells, natural killer cells and B cells. GATA2 PVs are associated with an increased risk of myeloid malignancies and a predisposition to nontuberculous mycobacterial and human papillomavirus infections. Additionally, invasive fungal infections (IFIs) have been reported in individuals with GATA2 PVs, even in the absence of myeloid malignancies. In this report, we present the case of a 40-year-old man with Emberger syndrome (GATA2 mutation, recently diagnosed acute myeloid leukaemia [AML] and history of lymphedema with hearing loss) who developed Mucorales sinusitis while receiving his first course of remission induction chemotherapy. Additionally, we review the literature on all published cases of proven IFIs in patients with GATA2 PVs. Clinicians should be aware that patients with GATA2 PVs could be vulnerable to opportunistic IFIs, even in the absence of AML and antineoplastic therapy. Furthermore, the distinctly unusual occurrence of mucormycosis during the first course of induction chemotherapy for AML in our patient indicates that patients with germline GATA2 PVs receiving induction chemotherapy for AML might be at high risk for early onset of IFIs due to aggressive, opportunistic moulds.

Mucormycosis: update on clinical presentation, diagnosis, and treatment

PURPOSE OF REVIEW

Mucormycosis (MCR) is a common opportunistic mold infection, and Mucorales were recently designated by WHO as priority pathogens. The interest in this infection has risen significantly since the major outbreak of MCR in the context of the COVID-19 pandemic, particularly in India. Herein, we summarize recently (last 24 months) published information regarding clinical aspects of MCR.

RECENT FINDINGS

The disease remains protean in its clinical presentation, difficult to diagnose, and challenging to treat. In 2021, cases of COVID-19-associated mucormycosis (CAM) exploded in India during COVID-19 and manifested primarily as sino-orbital or sino-cerebral disease. Its classic risk factors included the triad of COVID-19, uncontrolled diabetes mellitus and use of corticosteroids. Despite difficulties in the timely diagnosis of MCR, significant progress has been made with the use of molecular techniques in blood to assist with earlier diagnosis, which can facilitate earlier appropriate therapy and improve outcomes. In addition, advances have been made in the use of imaging to stage the disease, determining what types of multimodal therapy are required depending on staging, and tissue-based identification of Mucorales.

SUMMARY

Although the outlook for MCR has improved, effective new antifungals, risk stratification, and the optimal multimodality approaches remain an unmet need.

Heterogenous lung inflammation CT patterns distinguish pneumonia and immune checkpoint inhibitor pneumonitis and complement blood biomarkers in acute myeloid leukemia: proof of concept

Background

Immune checkpoint inhibitors (ICI) may cause pneumonitis, resulting in potentially fatal lung inflammation. However, distinguishing pneumonitis from pneumonia is time-consuming and challenging. To fill this gap, we build an image-based tool, and further evaluate it clinically alongside relevant blood biomarkers.

Materials and methods

We studied CT images from 97 patients with pneumonia and 29 patients with pneumonitis from acute myeloid leukemia treated with ICIs. We developed a CT-derived signature using a habitat imaging algorithm, whereby infected lungs are segregated into clusters ("habitats"). We validated the model and compared it with a clinical-blood model to determine whether imaging can add diagnostic value.

Results

Habitat imaging revealed intrinsic lung inflammation patterns by identifying 5 distinct subregions, correlating to lung parenchyma, consolidation, heterogenous ground-glass opacity (GGO), and GGO-consolidation transition. Consequently, our proposed habitat model (accuracy of 79%, sensitivity of 48%, and specificity of 88%) outperformed the clinical-blood model (accuracy of 68%, sensitivity of 14%, and specificity of 85%) for classifying pneumonia versus pneumonitis. Integrating imaging and blood achieved the optimal performance (accuracy of 81%, sensitivity of 52% and specificity of 90%). Using this imaging-blood composite model, the post-test probability for detecting pneumonitis increased from 23% to 61%, significantly (p = 1.5E - 9) higher than the clinical and blood model (post-test probability of 22%).

Conclusion

Habitat imaging represents a step forward in the image-based detection of pneumonia and pneumonitis, which can complement known blood biomarkers. Further work is needed to validate and fine tune this imaging-blood composite model and further improve its sensitivity to detect pneumonitis.

Mucormycosis in 2023: an update on pathogenesis and management

Mucormycosis (MCR) is an emerging and frequently lethal fungal infection caused by the Mucorales family, with Rhizopus, Mucor, and Lichtheimia, accounting for > 90% of all cases. MCR is seen in patients with severe immunosuppression such as those with hematologic malignancy or transplantation, Diabetes Mellitus (DM) and diabetic ketoacidosis (DKA) and immunocompetent patients with severe wounds. The recent SARS COV2 epidemy in India has resulted in a tremendous increase in MCR cases, typically seen in the setting of uncontrolled DM and corticosteroid use. In addition to the diversity of affected hosts, MCR has pleiotropic clinical presentations, with rhino-orbital/rhino-cerebral, sino-pulmonary and necrotizing cutaneous forms being the predominant manifestations. Major insights in MCR pathogenesis have brought into focus the host receptors (GRP78) and signaling pathways (EGFR activation cascade) as well as the adhesins used by Mucorales for invasion. Furthermore, studies have expanded on the importance of iron availability and the complex regulation of iron homeostasis, as well as the pivotal role of mycotoxins as key factors for tissue invasion. The molecular toolbox to study Mucorales pathogenesis remains underdeveloped, but promise is brought by RNAi and CRISPR/Cas9 approaches. Important recent advancements have been made in early, culture-independent molecular diagnosis of MCR. However, development of new potent antifungals against Mucorales remains an unmet need. Therapy of MCR is multidisciplinary and requires a high index of suspicion for initiation of early Mucorales-active antifungals. Reversal of underlying immunosuppression, if feasible, rapid DKA correction and in selected patients, surgical debulking are crucial for improved outcomes.

Special Issue "Diagnosis and Treatment of Invasive Pulmonary Fungal Infections"

The Guest Editors Dr [...].

Development of a Corticosteroid-Immunosuppressed Mouse Model to Study the Pathogenesis and Therapy of Influenza-Associated Pulmonary Aspergillosis

Influenza-associated pulmonary aspergillosis (IAPA) is a feared complication in patients with influenza tracheobronchitis, especially those receiving corticosteroids. Herein, we established a novel IAPA mouse model with low-inoculum Aspergillus infection and compared outcomes in mice with and without cortisone acetate (CA) immunosuppression. CA was an independent predictor of increased morbidity/mortality in mice with IAPA. Early antifungal treatment with liposomal amphotericin B was pivotal to improve IAPA outcomes in CA-immunosuppressed mice, even after prior antiviral therapy with oseltamivir. In summary, our model recapitulates key clinical features of IAPA and provides a robust preclinical platform to study the pathogenesis and treatment of IAPA.

Clinical Uses of Inhaled Antifungals for Invasive Pulmonary Fungal Disease: Promises and Challenges

The role of inhaled antifungals for prophylaxis and treatment of invasive fungal pneumonias remains undefined. Herein we summarize recent clinically relevant literature in high-risk groups such as neutropenic hematology patients, including those undergoing stem cell transplant, lung and other solid transplant recipients, and those with sequential mold lung infections secondary to viral pneumonias. Although there are several limitations of the available data, inhaled liposomal amphotericin B administered 12.5 mg twice weekly could be an alternative method of prophylaxis in neutropenic populations at high risk for invasive fungal pneumonia where systemic triazoles are not tolerated. In addition, inhaled amphotericin B has been commonly used as prophylaxis, pre-emptive, or targeted therapy for lung transplant recipients but is considered as a secondary alternative for other solid organ transplant recipients. Inhaled amphotericin B seems promising as prophylaxis in fungal pneumonias secondary to viral pneumonias, influenza, and SARS CoV-2. Data remain limited for inhaled amphotericin for adjunct treatment, but the utility is feasible.

Neutropenic Enterocolitis: An Uncommon, but Fearsome Complication of Leukemia

Neutropenic enterocolitis (NEC) is a life-threatening condition occurring in severely neutropenic patients, following intensive chemotherapy for leukemia. Its pathogenesis is not entirely understood and believed to be multifactorial, including mucosal injury as a result of cytotoxic drugs, profound neutropenia, impaired host defense and possibly microbiota changes. Establishing an early diagnosis is key. The management of NEC remains undefined due to lack of high-quality clinical data. With a better understanding of the disease, a more conservative approach is preferred over surgical intervention. The involvement of a multi-disciplinary team, consisting of the oncologist, infectious diseases specialists and surgeons is highly recommended. This review aims to delineate insights into the pathophysiology and clinical presentation of NEC and to emphasize the diagnostic and therapeutic approach to this condition.

Invasive Mold Infections Following Hurricane Harvey-Houston, Texas

Background

Characterizing invasive mold infection (IMI) epidemiology in the context of large flooding events is important for public health planning and clinical decision making.

Methods

We assessed IMI incidence (per 10 000 healthcare encounters) 1 year before and after Hurricane Harvey at 4 hospitals in Houston, Texas. Potential IMI cases were assigned as proven or probable cases using established definitions, and surveillance cases using a novel definition. We used rate ratios to describe IMI incidence and multivariable logistic regression to examine patient characteristics associated with IMI case status.

Results

IMI incidence was significantly higher posthurricane (3.69 cases) than prehurricane (2.50 cases) (rate ratio, 1.48 [95% confidence interval, 1.10-2.00]), largely driven by surveillance IMI cases. Aspergillus was the most common species cultured (33.5% prehurricane and 39.9% posthurricane). About one-quarter (25.8%) of IMI patients lacked classical IMI risk factors such as hematologic malignancy and transplantations. Overall, 45.1% of IMI patients received intensive care, and in-hospital all-cause mortality was 24.2%.

Conclusions

IMI incidence likely increased following Hurricane Harvey and outcomes for IMI patients were severe. Patient and clinician education on IMI prevention and identification is warranted, particularly as the frequency of extreme weather events increases due to climate change.

Multimodal analysis of the COVID-19-associated mucormycosis outbreak in Delhi, India indicates the convergence of clinical and environmental risk factors

BACKGROUND

The aetiology of the major outbreak of COVID-19-associated mucormycosis (CAM) in India in spring 2021 remains incompletely understood. Herein, we provide a multifaceted and multi-institutional analysis of clinical, pathogen-related, environmental and healthcare-related factors during CAM outbreak in the metropolitan New Delhi area.

METHODS

We reviewed medical records of all patients diagnosed with biopsy-proven CAM (n = 50) at 7 hospitals in the New Delhi, and NCR area in April-June 2021. Two multivariate logistic regression models were used to compare clinical characteristics of CAM cases with COVID-19-hospitalised contemporary patients as controls (n = 69). Additionally, meteorological parameters and mould spore concentrations in outdoor air were analysed. Selected hospital fomites were cultured. Mucorales isolates from CAM patients were analysed by ITS sequencing and whole-genome sequencing (WGS).

RESULTS

Independent risk factors for CAM identified by multivariate analysis were previously or newly diagnosed diabetes mellitus, active cancer and severe COVID-19 infection. Supplemental oxygen, remdesivir therapy and ICU admission for COVID-19 were associated with reduced CAM risk. The CAM incidence peak was preceded by an uptick in environmental spore concentrations in the preceding 3-4 weeks that correlated with increasing temperature, high evaporation and decreasing relative humidity. Rhizopus was the most common genus isolated, but we also identified two cases of the uncommon Mucorales, Lichtheimia ornata. WGS found no clonal population of patient isolates. No Mucorales were cultured from hospital fomites.

CONCLUSIONS

An intersection of host and environmental factors contributed to the emergence of CAM. Surrogates of access to advanced COVID-19 treatment were associated with lower CAM risk.

International multicenter study comparing COVID-19 in patients with cancer to patients without cancer: Impact of risk factors and treatment modalities on survivorship

Background

In this international multicenter study, we aimed to determine the independent risk factors associated with increased 30 day mortality and the impact of cancer and novel treatment modalities in a large group of patients with and without cancer with COVID-19 from multiple countries.

Methods

We retrospectively collected de-identified data on a cohort of patients with and without cancer diagnosed with COVID-19 between January and November 2020 from 16 international centers.

Results

We analyzed 3966 COVID-19 confirmed patients, 1115 with cancer and 2851 without cancer patients. Patients with cancer were more likely to be pancytopenic and have a smoking history, pulmonary disorders, hypertension, diabetes mellitus, and corticosteroid use in the preceding 2 wk (p≤0.01). In addition, they were more likely to present with higher inflammatory biomarkers (D-dimer, ferritin, and procalcitonin) but were less likely to present with clinical symptoms (p≤0.01). By country-adjusted multivariable logistic regression analyses, cancer was not found to be an independent risk factor for 30 day mortality (p=0.18), whereas lymphopenia was independently associated with increased mortality in all patients and in patients with cancer. Older age (≥65y) was the strongest predictor of 30 day mortality in all patients (OR = 4.47, p<0.0001). Remdesivir was the only therapeutic agent independently associated with decreased 30 day mortality (OR = 0.64, p=0.036). Among patients on low-flow oxygen at admission, patients who received remdesivir had a lower 30 day mortality rate than those who did not (5.9 vs 17.6%; p=0.03).

Conclusions

Increased 30 day all-cause mortality from COVID-19 was not independently associated with cancer but was independently associated with lymphopenia often observed in hematolgic malignancy. Remdesivir, particularly in patients with cancer receiving low-flow oxygen, can reduce 30 day all-cause mortality.

Funding

National Cancer Institute and National Institutes of Health.

Acute Peritoneal Histoplasmosis Mimicking Ovarian Cancer and Review of the Literature on Histoplasma Peritonitis

Peritoneal histoplasmosis is a rare entity with few cases reported in the literature. We present a case of isolated acute peritoneal histoplasmosis that mimicked an advanced ovarian malignancy in a patient undergoing antitumor necrosis factor therapy for rheumatoid arthritis. We also reviewed the literature on Histoplasma peritonitis.

Impact of Hyperglycemia and Diabetes Mellitus on Breakthrough Mucormycosis Outcomes in Patients with Hematologic Malignancies-Complex and Intriguing Associations

Mucormycosis (MCR) is frequently associated with diabetic ketoacidosis and hyperglycemia, as well as hematologic malignancies (HMs) and hematopoietic stem cell transplantation (HSCT). However, little is known about the effect of hyperglycemia on MCR outcomes in patients with HMs. We therefore conducted a retrospective cohort study of adult patients hospitalized with MCR and HM or HSCT (n = 103) at MD Anderson Cancer Center from April 2000 through to April 2020. Twenty-three patients (22%) had documented episodes of severe hyperglycemia. Sixty patients had >5 serum glucose measurements within 28 days prior to MCR symptom onset; of those, 14 (23%) met the criteria for persistent hyperglycemia. Sixteen patients (16%) received insulin prior to admission. The crude mortality 42 days from the onset of MCR symptoms in our cohort was 31%. Neither severe nor persistent hyperglycemia were associated with excess mortality. Insulin use prior to index admission was associated with decreased 42-day mortality on univariate analysis (p = 0.031). In conclusion, in a setting of high crude mortality, severe and/or persistent hyperglycemia do not appear to be associated with excess mortality in patients with HM or HSCT developing MCR. Insulin use prior to MCR diagnosis may be associated with decreased mortality, although further research is needed to validate this effect and to study its mechanistic underpinnings.

Osteoarticular Mycoses

Osteoarticular mycoses are chronic debilitating infections that require extended courses of antifungal therapy and may warrant expert surgical intervention. As there has been no comprehensive review of these diseases, the International Consortium for Osteoarticular Mycoses prepared a definitive treatise for this important class of infections. Among the etiologies of osteoarticular mycoses are Candida spp., Aspergillus spp., Mucorales, dematiaceous fungi, non-Aspergillus hyaline molds, and endemic mycoses, including those caused by Histoplasma capsulatum, Blastomyces dermatitidis, and Coccidioides species. This review analyzes the history, epidemiology, pathogenesis, clinical manifestations, diagnostic approaches, inflammatory biomarkers, diagnostic imaging modalities, treatments, and outcomes of osteomyelitis and septic arthritis caused by these organisms. Candida osteomyelitis and Candida arthritis are associated with greater events of hematogenous dissemination than those of most other osteoarticular mycoses. Traumatic inoculation is more commonly associated with osteoarticular mycoses caused by Aspergillus and non-Aspergillus molds. Synovial fluid cultures are highly sensitive in the detection of Candida and Aspergillus arthritis. Relapsed infection, particularly in Candida arthritis, may develop in relation to an inadequate duration of therapy. Overall mortality reflects survival from disseminated infection and underlying host factors.

Infections Simulating Immune Checkpoint Inhibitor Toxicities: Uncommon and Deceptive

Use of immune checkpoint inhibitors (ICIs), a revolutionary treatment in modern oncology, is frequently complicated by immune-related adverse events (irAEs), which can be confused with infections, and vice versa, thus complicating management decisions. In this study, we review the published cases of infections as simulators of irAEs in cancer patients.

Impact of Molecular Syndromic Diagnosis of Severe Pneumonia in the Management of Critically Ill Patients

The impact of syndromic molecular diagnosis in the management of nosocomial infections caused by multidrug-resistant (MDR) and extensively drug-resistant (XDR) pathogens has been incompletely characterized. We evaluated the performance of a molecular syndromic platform (BioFire FilmArray-Pneumonia plus Panel) in patients with pneumonia in the intensive care unit (ICU) of a University Hospital in Greece over a 2-year period. We evaluated 79 consecutive patients diagnosed with pneumonia in the ICU (2018-2020), including 55 patients with ventilator associated pneumonia (VAP). We included 40 control patients diagnosed with pneumonia in the ICU the year before the study (2017-2018). We identified 16 cases of VAP due to XDR bacterial pathogens. We found an excellent agreement (89.4% 76/85 reported results) between the results of syndromic platform and conventional cultures of tracheal aspirates. The molecular syndromic test significantly improved time to diagnosis versus conventional culture (3.5 h vs 72 h, P < 0.0001), and identified new pathogens not detected by cultures in 49% of the cases. However, three cases of pneumonia with targets not included in the molecular platform, were not detected. Implementation of the molecular syndromic facilitated treatment modification from broad to narrow spectrum antimicrobial therapy, resulting in significant reductions in antibiotic consumption in the study group compared to the control group, without a negative impact in patient outcome. The implementation of syndromic molecular diagnosis in critically ill patients with pneumonia is associated with timely and improved diagnosis and has significant impact on reduction of antibiotic consumption. IMPORTANCE The impact of syndromic molecular diagnosis in the management of nosocomial infections caused by MDR/XDR pathogens has been incompletely characterized. We evaluated the performance of a molecular syndromic platform (BioFire FilmArray -Pneumonia plus Panel) in 79 patients with pneumonia in the intensive care unit (ICU) of a University Hospital in Greece over a 2-year period (2018-2020) compared to 40 control patients diagnosed with pneumonia in the ICU the year before the study (2017-2018). Importantly, implementation of syndromic pneumonia panel improved time to diagnosis, identified new pathogens not detected by cultures in 49% of the cases and resulted in a significant reduction in antibiotic consumption compared to the year before initiation of the study without a negative impact in mortality of patients. Collectively, our study demonstrates the positive value of PCR syndromic testing in the management of pneumonia in ICUs high rates of MDR/XDR nosocomial pathogens.

Checkpoint inhibitors as immunotherapy for fungal infections: Promises, challenges, and unanswered questions

Opportunistic fungal infections have high mortality in patients with severe immune dysfunction. Growing evidence suggests that the immune environment of invasive fungal infections and cancers share common features of immune cell exhaustion through activation of immune checkpoint pathways. This observation gave rise to several preclinical studies and clinical case reports describing blockade of the Programmed Cell Death Protein 1 and Cytotoxic T-Lymphocyte Antigen 4 immune checkpoint pathways as an adjunct immune enhancement strategy to treat opportunistic fungal infections. The first part of this review summarizes the emerging evidence for contributions of checkpoint pathways to the immunopathology of fungal sepsis, opportunistic mold infections, and dimorphic fungal infections. We then review the potential merits of immune checkpoint inhibitors (ICIs) as an antifungal immunotherapy, including the incomplete knowledge of the mechanisms involved in both immuno-protective effects and toxicities. In the second part of this review, we discuss the limitations of the current evidence and the many unknowns about ICIs as an antifungal immune enhancement strategy. Based on these gaps of knowledge and lessons learned from cancer immunology studies, we outline a research agenda to determine a "sweet spot" for ICIs in medical mycology. We specifically discuss the importance of more nuanced animal models, the need to study ICI-based combination therapy, potential ICI resistance, the role of the immune microenvironment, and the impact of ICIs given as part of oncological therapies on the natural immunity to various pathogenic fungi.

Quandaries of deciding when to change first-line therapy in invasive pulmonary aspergillosis

We read the excellent viewpoint by Slavin et al. (J Antimicrob Chemother 2022; 77: 16-23) that draws upon the experience of an advisory board of notable experts to comprehensively address many of the clinical factors that drive the need for changes in antifungal therapy for invasive aspergillosis (IA). As noted by the authors, there remains a paucity of quality data to support many of the decisions faced by clinicians managing patients with IA. However, we would like to highlight several other important issues, not fully addressed in that viewpoint, that play an important role in deciding when to change antifungal therapy for IA.

Investigational Antifungal Agents for Invasive Mycoses: A Clinical Perspective

Treatment of invasive fungal infections (IFIs) remains challenging, because of the limitations of the current antifungal agents (ie, mode of administration, toxicity, and drug-drug interactions) and the emergence of resistant fungal pathogens. Therefore, there is an urgent need to expand our antifungal armamentarium. Several compounds are reaching the stage of phase II or III clinical assessment. These include new drugs within the existing antifungal classes or displaying similar mechanism of activity with improved pharmacologic properties (rezafungin and ibrexafungerp) or first-in-class drugs with novel mechanisms of action (olorofim and fosmanogepix). Although critical information regarding the performance of these agents in heavily immunosuppressed patients is pending, they may provide useful additions to current therapies in some clinical scenarios, including IFIs caused by azole-resistant Aspergillus or multiresistant fungal pathogens (eg, Candida auris, Lomentospora prolificans). However, their limited activity against Mucorales and some other opportunistic molds (eg, some Fusarium spp.) persists as a major unmet need.

International Multicenter Study Comparing Cancer to Non-Cancer Patients with COVID-19: Impact of Risk Factors and Treatment Modalities on Survivorship

Background

In this international multicenter study we aimed to determine the independent risk factors associated with increased 30-day mortality and the impact of novel treatment modalities in a large group of cancer and non-cancer patients with COVID-19 from multiple countries.

Methods

We retrospectively collected de-identified data on a cohort of cancer and non-cancer patients diagnosed with COVID-19 between January and November 2020, from 16 international centers.

Results

We analyzed 3966 COVID-19 confirmed patients, 1115 cancer and 2851 non-cancer patients. Cancer patients were more likely to be pancytopenic, and have a smoking history, pulmonary disorders, hypertension, diabetes mellitus, and corticosteroid use in the preceding two weeks (p≤0.01). In addition, they were more likely to present with higher inflammatory biomarkers (D-dimer, ferritin and procalcitonin), but were less likely to present with clinical symptoms (p≤0.01). By multivariable logistic regression analysis, cancer was an independent risk factor for 30-day mortality (OR 1.46; 95% CI 1.03 to 2.07; p=0.035). Older age (≥65 years) was the strongest predictor of 30-day mortality in all patients (OR 4.55; 95% CI 3.34 to6.20; p< 0.0001). Remdesivir was the only therapeutic agent independently associated with decreased 30-day mortality (OR 0.58; CI 0.39-0.88; p=0.009). Among patients on low-flow oxygen at admission, patients who received remdesivir had a lower 30-day mortality rate than those who did not (5.9% vs 17.6%; p=0.03).

Conclusions

Cancer is an independent risk factor for increased 30-day all-cause mortality from COVID-19. Remdesivir, particularly in patients receiving low-flow oxygen, can reduce 30-day all-cause mortality.

Condensed Abstract

In this large multicenter worldwide study of 4015 patients with COVID-19 that included 1115 patients with cancer, we found that cancer is an independent risk factor for increased 30-day all-cause mortality. Remdesivir is a promising treatment modality to reduce 30-day all-cause mortality.

Noninvasive Testing and Surrogate Markers in Invasive Fungal Diseases

Invasive fungal infections continue to increase as at-risk populations expand. The high associated morbidity and mortality with fungal diseases mandate the continued investigation of novel antifungal agents and diagnostic strategies that include surrogate biomarkers. Biologic markers of disease are useful prognostic indicators during clinical care, and their use in place of traditional survival end points may allow for more rapid conduct of clinical trials requiring fewer participants, decreased trial expense, and limited need for long-term follow-up. A number of fungal biomarkers have been developed and extensively evaluated in prospective clinical trials and small series. We examine the evidence for these surrogate biomarkers in this review and provide recommendations for clinicians and regulatory authorities.

Infectious Complications Among Patients With AML Treated With Immune Checkpoint Inhibitors

BACKGROUND

The incidence and spectrum of infections in acute myeloid leukemia (AML) patients treated with immune checkpoint inhibitors (CPIs) in combination with a hypomethylating agents (HMAs) is not known. Nivolumab is a PD-1 checkpoint inhibitor approved in many solid tumors and lymphoma.

MATERIALS/METHODS

We performed a retrospective cohort study of 75 adult patients at MD Anderson Cancer Center with relapsed/refractory AML treated with azacitidine and nivolumab or with nivolumab and ipilimumab from March 2016 through March 2020 and described the infectious complications that occurred during their treatment.

RESULTS

Sixty-four (85%) patients developed an infection during the study period, and bacterial infections were by far the most common type of infection. A comparison of risk factors and characteristic between the 75 patients on CPIs who developed infection and those who did not found that corticosteroid use (odds ratio [OR], 28; 95% confidence interval [CI], 1.6-490; P =.02) and lymphopenia (OR, 4; 95% CI, 1-15.5; P =.04) were significantly associated with infections.

CONCLUSION

Patient with relapsed/refractory AML treated with salvage CPI-based therapy were more likely to develop infections when treated with corticosteroids in the setting of an immune-related adverse event, compared to those who were not.

Invasive mould infections in patients from floodwater-damaged areas after hurricane Harvey - a closer look at an immunocompromised cancer patient population

OBJECTIVES

Extensive floodwater damage following hurricane Harvey raised concerns of increase in invasive mould infections (IMIs), especially in immunocompromised patients. To more comprehensively characterize the IMI landscape pre- and post-Harvey, we used a modified, less restrictive clinical IMI (mcIMI) definition by incorporating therapeutic-intent antifungal drug prescriptions combined with an expanded list of host and clinical features.

METHODS

We reviewed 103 patients at MD Anderson Cancer Center (Houston, Texas), who lived in Harvey-affected counties and had mould-positive cultures within 12 months pre-/post-Harvey (36 and 67 patients, respectively). Cases were classified as proven or probable IMI (EORTC/MSG criteria), mcIMI, or colonization/contamination. We also compared in-hospital mortality and 42- day survival outcomes of patients with mcIMI pre-/post-Harvey.

RESULTS

The number of patients with mould- positive cultures from Harvey-affected counties almost doubled from 36 pre- Harvey to 67 post- Harvey (p < 0.01). In contrast, no significant changes in (mc)IMI incidence post-Harvey nor changes in the aetiological mould genera were noted. However, patients with mcIMIs from flood affected areas had significantly higher in-hospital mortality (p = 0.01).

CONCLUSIONS

We observed increased colonization but no excess cases of (mc)IMIs in immunosuppressed cancer patients from affected areas following a large flooding event such as hurricane Harvey.

Candida auris Bloodstream Infection Induces Upregulation of the PD-1/PD-L1 Immune Checkpoint Pathway in an Immunocompetent Mouse Model

Candida auris is a globally spreading yeast pathogen causing bloodstream infections with high mortality in critically ill patients. The inherent antifungal drug resistance of most C. auris isolates and threat of multidrug-resistant strains create a need for adjunct immunotherapeutic strategies. While C. albicans candidemia was shown to induce immune paralysis and activation of inhibitory immune checkpoints, in vivo data on host responses to C. auris bloodstream infection are lacking as is an immunocompetent murine infection model to study the immunopathology and immunotherapy of C. auris sepsis. Therefore, herein, we developed an immunocompetent C. auris sepsis model by intravenously infecting C57BL/6 mice with 1.5 × 108 to 8 × 108 yeast cells of aggregate-forming (AR-0384) and nonaggregative (AR-0381) C. auris reference isolates. Both isolates caused reproducible, inoculum-dependent increasing morbidity, mortality, and fungal burden in kidney tissue. Notably, morbidity and mortality outcomes were partially decoupled from fungal burden, suggesting a role of additional modulators of disease severity such as host immune responses. Flow cytometric analyses of splenic immune cells revealed significant upregulation of the programmed cell death protein 1 (PD-1) on T cells and its ligand PD-L1 on macrophages from mice infected with C. auris AR-0384 compared to uninfected mice. PD-L1 expression on macrophages from AR-0384-infected mice strongly correlated with fungal tissue burden (Spearman's rank correlation coefficient [ρ] = 0.95). Altogether, our findings suggest that C. auris sepsis promotes a suppressive immune phenotype through PD-1/PD-L1 induction, supporting further exploration of PD-1/PD-L1 blockade as an immunotherapeutic strategy to mitigate C. auris candidiasis. IMPORTANCE Health authorities consider Candida auris to be one of the most serious emerging nosocomial pathogens due to its transmissibility, resistance to disinfection procedures, and frequent antifungal drug resistance. The frequency of multidrug-resistant C. auris isolates necessitates the development of novel therapeutic platforms, including immunotherapy. However, in vivo data on host interactions with C. auris are scarce, compounded by the lack of reliable immunocompetent mammalian models of C. auris candidemia. Herein, we describe a C. auris sepsis model in immunocompetent C57BL/6 mice and demonstrate reproducible and inoculum-dependent acute infection with both aggregate-forming and nonaggregative reference isolates from different clades. Furthermore, we show that C. auris sepsis induces upregulation of the PD-1/PD-L1 immune checkpoint pathway in infected mice, raising the potential of a therapeutic benefit of immune checkpoint blockade. Our immunocompetent model of C. auris sepsis could provide a facile preclinical platform to thoroughly investigate immune checkpoint blockade and combination therapy with antifungals.

Pneumonitis after immune checkpoint inhibitor therapies in patients with acute myeloid leukemia: A retrospective cohort study

BACKGROUND

Immune checkpoint inhibitors (ICI), combined with hypomethylating agents, can be used to treat acute myeloid leukemia (AML), but this strategy results in a high rate of pneumonitis. The authors sought to determine risk factors for pneumonitis development and whether pneumonitis increased mortality.

METHODS

The authors conducted a retrospective review of 258 AML patients who received ICI-containing regimens from 2016 to 2018. A multidisciplinary adjudication committee diagnosed pneumonia and pneumonitis by reviewing symptoms, imaging, microbiology, and response to therapies. To measure risk factors for pneumonitis and mortality, multivariate Cox proportional hazards models were constructed. Pneumonia, pneumonitis, and disease progression were modeled as a time-dependent variable and incorporated a standard risk set modifying variables into the models.

RESULTS

Thirty patients developed pneumonitis (12%). Of these, 17 had partial or complete resolution, whereas 13 patients died from pneumonitis. Increasing age (hazard ratio [HR], 1.04 per year; 95% confidence interval [CI], 1.00-1.08), and baseline shortness of breath increased pneumonitis risk (HR, 2.51; 95% CI, 1.13-5.55). Female sex (HR, 0.33; 95% CI, 0.15-0.70) and increasing platelet count (HR, 0.52 per log-unit increase; 95% CI, 0.30-0.92) decreased pneumonitis risk. In adjusted models, ICI-related pneumonitis significantly increased mortality (HR, 2.84; 95% CI, 1.84-4.37).

CONCLUSIONS

ICI-related pneumonitis occurs at a high rate in AML patients and increases mortality.

LAY SUMMARY

Immune checkpoint inhibitors (ICIs) remove inhibitory signals that reduce T-cell function and allow T-cells to better attack cancer cells. In acute myeloid leukemia (AML), the effectiveness of ICIs is limited in part by inflammation of the lung, called pneumonitis. This study reviewed 258 patients with AML who received ICIs and identified 30 patients who developed pneumonitis, nearly half of whom died. Older age and baseline shortness of breath increased pneumonitis risk, whereas female sex and higher baseline platelet counts decreased pneumonitis risk. Pneumonitis increased mortality by nearly 3-fold. This work highlights the significant harm imposed by pneumonitis after ICI therapies.

Oral and Stool Microbiome Coalescence and Its Association With Antibiotic Exposure in Acute Leukemia Patients

Failure to maintain segregation of oral and gut microbial communities has been linked to several diseases. We sought to characterize oral-fecal microbiome community coalescence, ectopic extension of oral bacteria, clinical variables contributing to this phenomenon, and associated infectious consequences by analyzing the 16S rRNA V4 sequences of longitudinal fecal (n=551) and oral (n=737) samples from 97 patients with acute myeloid leukemia (AML) receiving induction chemotherapy (IC). Clustering observed in permutation based multivariate analysis of variance (PERMANOVA) of Bray-Curtis dissimilarity and PCoA plot of UniFrac distances between intra-patient longitudinal oral-stool sample pairs suggested potential oral-stool microbial community coalescence. Bray-Curtis dissimilarities and UniFrac distances were used to create an objective definition of microbial community coalescence. We determined that only 23 of the 92 patients exhibited oral-stool community coalescence. This was validated through a linear mixed model which determined that patients who experienced coalescence had an increased proportion of shared to unique OTUs between their oral-stool sample pairs over time compared to non-coalesced patients. Evaluation of longitudinal microbial characteristics revealed that patients who experienced coalescence had increased stool abundance of Streptococcus and Stenotrophomonas compared to non-coalesced patients. When treated as a time-varying covariate, each additional day of linezolid (HR 1.15, 95% CI 1.06 – 1.24, P <0.001), meropenem (HR 1.13, 95% CI 1.05 – 1.21, P = 0.001), metronidazole (HR 1.13, 95% CI 1.05 – 1.21, P = 0.001), and cefepime (HR 1.10, 95% CI 1.01 – 1.18, P = 0.021) increased the hazard of oral-stool microbial community coalescence. Levofloxacin receipt was associated with a lower risk of microbiome community coalescence (HR 0.75, 95% CI 0.61 – 0.93, P = 0.009). By the time of neutrophil recovery, the relative abundance of Bacteroidia (P<0.001), Fusobacteria (P=0.012), and Clostridia (P=0.013) in the stool were significantly lower in patients with oral-gut community coalescence. Exhibiting oral-stool community coalescence was associated with the occurrence of infections prior to neutrophil recovery (P=0.002), as well as infections during the 90 days post neutrophil recovery (P=0.027). This work elucidates specific antimicrobial effects on microbial ecology and furthers the understanding of oral/intestinal microbial biogeography and its implications for adverse clinical outcomes.

Comparison of mold active triazoles as primary antifungal prophylaxis in patients with newly diagnosed acute myeloid leukemia in the era of molecularly targeted therapies

BACKGROUND

Multiple factors influence the choice of primary antifungal prophylaxis (PAP) in patients with acute myeloid leukemia (AML) undergoing remission induction chemotherapy (RIC) given the recent incorporation of targeted leukemia therapies into these regimens.

METHODS

We evaluated the incidence and characteristics of breakthrough IFI (bIFI) in 277 adult patients with newly diagnosed AML undergoing RIC with high-intensity, or low-intensity venetoclax-containing therapy. Patients receiving posaconazole (PCZ), voriconazole (VCZ), or isavuconazole (ISA) for > 5 days as PAP during RIC were included. Echinocandin use prior to, but not concomitantly with, the PAP azole was allowed. IFI (modified EORTC/MSG criteria) occurring after > 5 days of continuous azole exposure or within 14 days of discontinuation were considered bIFI.

RESULTS

Proven or probable bIFI were observed in 11 patients (4%). The incidence of bIFI was 2.9% for PCZ, 4.8% for VCZ, and 5.7% for ISA (p=0.55). 161 patients (58%) received echinocandin prophylaxis prior to azole initiation. Neither echinocandin exposure nor chemotherapy intensity impacted bIFI rate. Patients with bIFI had a lower rate of absolute neutrophil count recovery >1000 cells/µL (64% vs 90%, p=0.021) or complete remission (CR; 18% vs 66%, p=0.002) after RIC. Thirty-eight patients (14%) discontinued PAP due to toxicity, most often hepatotoxicity. Discontinuation due to hepatotoxicity was similar among azoles (PCZ: 13%; VCZ: 15%; ISA: 13%).

CONCLUSIONS

The rate of bIFI is low during RIC in patients with newly diagnosed AML receiving any of the mold-active triazoles as PAP. Neutrophil recovery and achievement of CR are important for bIFI risk.

Clumping Morphology Influences Virulence Uncoupled from Echinocandin Resistance in Candida glabrata

Here, we report two paired sets of an index wild-type Candida glabrata bloodstream isolate and subsequent echinocandin-resistant FKS mutant. One paired set exhibited a higher proportion of clumping cells and was more virulent in the invertebrate host Galleria mellonella than the other paired set. No virulence difference between the paired index and FKS strains was observed. These findings imply a potential link of clumping morphology with virulence in C. glabrata that is uncoupled from FKS-mediated echinocandin resistance. IMPORTANCE Candida glabrata is a leading cause of invasive candidiasis. In contrast to other species, it has a high propensity for developing resistance to echinocandins, which are the first-line treatment. Unlike the dimorphic Candida albicans which can grow invasive filamentous hyphae, C. glabrata lacks this ability. Here, we report a link between virulence and clumping cell morphology in two different sets of clinical C. glabrata strains obtained from patients failing echinocandin therapy. One set of paired strains (echinocandin-susceptible and subsequent resistant mutant) had a high proportion of clumping cells in the population and were significantly more virulent than another set which had fewer clumping cells. Additionally, we corroborate that echinocandin resistance does not impart a significant fitness cost. Our findings suggest that clumping morphology may be an important but previously underestimated virulence factor for C. glabrata and also aid our understand for the high prevalence of resistance observed in this species.

Blockade of the PD-1/PD-L1 Immune Checkpoint Pathway Improves Infection Outcomes and Enhances Fungicidal Host Defense in a Murine Model of Invasive Pulmonary Mucormycosis

Anecdotal clinical reports suggested a benefit of adjunct immune checkpoint inhibitors (ICIs) to treat invasive mucormycosis. However, proof-of-concept data in animal models and mechanistic insights into the effects of ICIs on host defense against Mucorales are lacking. Therefore, we studied the effects of PD-1 and PD-L1 inhibitors (4 doses of 250 µg/kg) on outcomes and immunopathology of invasive pulmonary mucormycosis (IPM) in cyclophosphamide- and cortisone acetate-immunosuppressed mice. Rhizopus arrhizus-infected mice receiving either of the ICI treatments had significantly improved survival, less morbidity, and lower fungal burden compared to isotype-treated infected mice. While early improvement of morbidity/mortality was comparable between the ICI treatments, anti-PD-L1 provided more consistent sustained protection through day 7 post-infection than anti-PD-1. Both ICIs enhanced the fungicidal activity of ex-vivo splenocytes and effectively counteracted T-cell exhaustion; however, macrophages of ICI-treated mice showed compensatory upregulation of other checkpoint markers. Anti-PD-1 elicited stronger pulmonary release of proinflammatory cytokines and chemokines than anti-PD-L1, but also induced cytokines associated with potentially unfavorable type 2 T-helper-cell and regulatory T-cell responses. Although no signs of hyperinflammatory toxicity were observed, mice with IPM receiving ICIs, particularly anti-PD-1, had elevated serum levels of IL-6, a cytokine linked to ICI toxicities. Altogether, inhibition of the PD-1/PD-L1 pathway improved clinical outcomes of IPM in immunosuppressed mice, even without concomitant antifungals. PD-L1 inhibition yielded more favorable immune responses and more consistent protection from IPM-associated morbidity and mortality than PD-1 blockade. Future dose-effect studies are needed to define the “sweet spot” between ICI-induced augmentation of antifungal immunity and potential immunotoxicities.

Drosophila melanogaster as a Rapid and Reliable In Vivo Infection Model to Study the Emerging Yeast Pathogen Candida auris

While mammalian models remain the gold standard to study invasive mycoses, mini-host invertebrate models have provided complementary platforms for explorative investigations of fungal pathogenesis, host-pathogen interplay, and antifungal therapy. Specifically, our group has established Toll-deficient Drosophila melanogaster flies as a facile and cost-effective model organism to study candidiasis, and we have recently expanded these studies to the emerging and frequently multidrug-resistant yeast pathogen Candida auris. Our proof-of-concept data suggest that fruit flies could hold a great promise for large-scale applications in antifungal drug discovery and the screening of C. auris (mutant) libraries with disparate pathogenic capacity. This chapter discusses the advantages and limitations of D. melanogaster to study C. auris candidiasis and provides a step-by-step guide for establishing and troubleshooting C. auris infection and antifungal treatment of Toll-deficient flies along with essential downstream readouts.

Protocol for fungal infection following the induction of epithelial cell loss in larval zebrafish

Epithelia provide the first line of defense against foreign pathogens, and disruption of tissue homeostasis frequently allows for opportunistic infections. Here we provide a protocol for induction of epithelial cell loss in zebrafish larvae, followed by infection with fungal pathogens. Details are provided for monitoring larval survival after infection, assessment of fungal burden, and prophylactic treatment with antifungal compounds. Limitations of the protocol include potential antifungal toxicity and high fungal inoculums to induce lethal infection with some pathogenic fungal species. For complete details on the use and execution of this protocol, please refer to Wurster et al. (2021).

Systemic antifungal therapy with isavuconazonium sulfate or other agents in adults with invasive mucormycosis or invasive aspergillosis (non-fumigatus): A multicentre, non-interventional registry study

BACKGROUND

Isavuconazole, administered as isavuconazonium sulfate (ISAVUSULF), is a broad-spectrum triazole agent for the treatment of invasive fungal disease. In phase 3 studies, ISAVUSULF showed comparable efficacy to voriconazole and amphotericin B for the treatment of invasive aspergillosis (IA) and invasive mucormycosis (IM), respectively.

OBJECTIVES

The objective of this study is to determine all-cause mortality and safety outcomes among adults with IM and/or IA non-fumigatus (nf) treated with ISAVUSULF or other antifungal therapies (AFT).

PATIENTS AND METHODS

This multicentre, non-interventional registry enrolled patients aged ≥18 years with IM or IA-nf who received systemic AFT from January 2016 to November 2018. Patients received primary ISAVUSULF, non-primary ISAVUSULF, or other AFT, as monotherapy or combination therapy. The primary end point was all-cause mortality at Days 42 and 84; safety outcomes were adverse drug reactions (ADRs) to ISAVUSULF.

RESULTS

Of 204 patients enrolled, 74 received primary ISAVUSULF, 30 non-primary ISAVUSULF, and 100 other AFT. All-cause mortality through Day 42 was numerically lower in the non-primary ISAVUSULF group than in the primary ISAVUSULF and other AFT groups, for patients with IM (20.0% vs. 33.3% and 41.3%, respectively) or IA-nf (0% vs. 14.8% and 17.8%, respectively). All-cause mortality tended to be lower with combination therapy than with monotherapy, except for patients with IM receiving primary ISAVUSULF. Of 111 patients receiving ISAVUSULF, 14 (12.6%) reported ADRs, of whom three (2.7%) developed serious ADRs. There were no drug-related deaths.

CONCLUSIONS

This study supports the effectiveness and tolerability of ISAVUSULF in clinical practice. Further research is required to confirm the value of ISAVUSULF combination therapy over monotherapy.

991. Blockade of the PD-1/PD-L1 Immune Checkpoint Pathway Improves Mortality, Infection Severity, and Fungal Clearance in an Immunosuppressed Murine Model of Invasive Pulmonary Mucormycosis

Background

Emerging experimental evidence suggests that immune checkpoint inhibitors (ICIs) enhance antifungal immunity. In addition, there is anecdotal evidence of potential benefit of adjunct PD-1 pathway blockade in patients with intractable mucormycosis. However, proof-of-concept data in animal models are lacking. Therefore, we compared the efficacy of PD-1 and PD-L1 inhibition in an immunosuppressed murine model of invasive pulmonary mucormycosis (IPM).

Methods

Female 8-9-week-old BALB/c mice were immunosuppressed with cyclophosphamide (150 mg/kg on days -4 and -1, 100 mg/kg on day +3) and cortisone acetate (300 mg/kg on day -1) and infected intranasally with 50,000 Rhizopus arrhizus spores (clinical isolate Ra-749, day 0). On days 0, +2, +4, and +6, mice received intraperitoneal injections of 250 µg/kg PD-1 or PD-L1 blocking antibodies versus (vs.) 250 µg/kg of the corresponding isotype antibodies (all antibodies from Leinco Technologies). Survival was monitored for 7 days post-infection. Infection severity was scored using the murine sepsis score (MSS, 0 = healthy to 3 = moribund). Fungal burden in lung tissue was determined by an 18S quantitative PCR assay on day +7 or upon death. 20 mice per treatment were assessed in 2 independent experiments.

Results

Control mice with IPM receiving either of the unspecific isotype antibodies developed severe infection (median MSS on day 7, 2.5-3.0) and had a high 7-day mortality (50-55%). Compared to the corresponding isotype control, PD-L1 inhibition provided a strong therapeutic benefit, significantly improving morbidity (median MSS = 1.0 vs. 2.5, p = 0.002), 7-day mortality (15% vs. 50%, p = 0.02), and fungal burden (3.6k vs. 27.2k spore equivalents/lung, p &lt; 0.001). In contrast, blockade of-PD-1 modestly yet non-significantly reduced infection severity (median MSS = 2.1 vs. 3.0, p = 0.48), 7-day mortality (35% vs, 55%, p = 0.12), and fungal burden (5.6k vs. 40.7k spore equivalents/lung, p = 0.09) compared to isotype control.

Conclusion

Even without concomitant antifungals, blockade of PD-L1 and to a lesser extent of PD-1 improved mortality, infection severity, and fungal clearance in immunosuppressed mice with IPM. Immune phenotyping studies are in progress to better understand the protective antifungal activity of ICIs in IPM.

Disclosures

Dimitrios P. Kontoyiannis, MD, Astellas (Consultant)Cidara Therapeutics (Advisor or Review Panel member)Gilead Sciences (Consultant, Grant/Research Support, Other Financial or Material Support, Honoraria)

22. International Multicenter Study Comparing Cancer to Non-Cancer Patients with COVID-19: Impact of Risk Factors and Treatment Modalities on Outcome

Background

Given the limited collaborative international studies that evaluated COVID-19 in patients with cancer in comparison to patients without cancer, we aimed to determine the independent risk factors associated with increased 30-day mortality and the impact of novel treatment modalities in a large group of cancer and non-cancer patients with COVID-19 from multiple countries.

Methods

We retrospectively collected de-identified data on cancer and non-cancer patients diagnosed with COVID-19 between January and November 2020, at 16 centers in Asia, Australia, Europe, North America, and South America. A logistic regression model was used to identify independent predictors of all-cause mortality within 30 days after COVID-19 diagnosis.

Results

Of the total 4015 COVID-19 confirmed patients entered, we analyzed 3966 patients, 1115 cancer and 2851 non-cancer patients. Cancer patients were older than non-cancer patients (median age, 61 vs 50 years; p< 0.0001); more likely to be pancytopenic , had pulmonary disorders, hypertension, diabetes mellitus. In addition, they were more likely to present with higher inflammatory biomarkers (D-dimer, ferritin and procalcitonin), but were less likely to present with clinical symptoms. By multivariable logistic regression analysis, cancer was an independent risk factor for 30-day mortality (OR 1.46; 95% CI 1.03 to 2.07; p=0.035). Older age (≥65 years) was the strongest predictor of 30-day mortality in all patients (OR 4.55; 95% CI 3.34 to 6.20; p< 0.0001). Remdesivir was the only therapeutic agent independently associated with decreased 30-day mortality (OR 0.58; CI 0.39-0.88; p=0.009). Among patients on low-flow oxygen at admission, patients who received remdesivir had a lower 30-day mortality rate than those who were on high flow oxygen (5.9% vs 17.6%; p=0.03). Patients transfused with convalescent plasma within 1 day of diagnosis had a lower 30-day mortality rate than those transfused later (1% vs 7%, p=0.04).

Conclusion

Cancer is an independent risk factor for increased 30-day all-cause mortality from COVID-19. Remdesivir, particularly in patients receiving low-flow oxygen, can reduce 30-day all-cause mortality, as well as convalescent plasma given early after COVID-19 diagnosis.

Disclosures

Roy F. Chemaly, MD, MPH, FACP, FIDSA, AiCuris (Grant/Research Support)Ansun Biopharma (Consultant, Grant/Research Support)Chimerix (Consultant, Grant/Research Support)Clinigen (Consultant)Genentech (Consultant, Grant/Research Support)Janssen (Consultant, Grant/Research Support)Karius (Grant/Research Support)Merck (Consultant, Grant/Research Support)Molecular Partners (Consultant, Advisor or Review Panel member)Novartis (Grant/Research Support)Oxford Immunotec (Consultant, Grant/Research Support)Partner Therapeutics (Consultant)Pulmotec (Consultant, Grant/Research Support)Shire/Takeda (Consultant, Grant/Research Support)Viracor (Grant/Research Support)Xenex (Grant/Research Support) Fareed Khawaja, MBBS, Eurofins Viracor (Research Grant or Support) Monica Slavin, MBBS,MD, F2G (Advisor or Review Panel member)Merck (Advisor or Review Panel member)Pfizer (Advisor or Review Panel member) Dimitrios P. Kontoyiannis, MD, Astellas (Consultant)Cidara Therapeutics (Advisor or Review Panel member)Gilead Sciences (Consultant, Grant/Research Support, Other Financial or Material Support, Honoraria)

124. Establishment of a Post-Influenza Aspergillosis Model in Corticosteroid-Immunosuppressed Mice

Background

Post-influenza aspergillosis (PIA) is a feared complication in patients with severe influenza, especially those receiving corticosteroids. However, validated murine models of PIA in a background of corticosteroid immunosuppression are lacking, compounding efforts to better characterize the immunopathology and treatment of this emerging entity.

Methods

8-week-old female BALB/c mice were infected with ~5% of the lethal dose of a mouse-adapted influenza A/Hong Kong/1968 (H3N2) strain (flu), delivered by aerosolization, versus control (aerosolized saline). Mice then received two intraperitoneal injections of 10 mg cortisone acetate (CA) or mock injections on days 5 and 8 after flu infection. On day 9, mice were intranasally challenged with 50,000 A. fumigatus AF-293 conidia or mock-infected with saline. Survival was monitored until day 16 and infection severity was scored using the modified murine sepsis score (MSS, 0 = healthy to 3 = moribund). Pulmonary fungal burden was determined by an 18S quantitative PCR assay on day 16 or upon death. 15-16 mice per group were assessed across 3 independent experiments.

Results

Flu infection alone caused modest early morbidity, followed by full recovery of the mice until day 16. Treatment with CA after flu infection led to 12% mortality and increased morbidity that persisted until day 16 (median MSS = 0.8). Similarly, mice infected with AF after CA treatment had 12% mortality and a median MSS of 0.7. Combination of all 3 challenges (flu, CA, and AF) led to 40% mortality and severe morbidity in surviving mice (median MSS = 2.7). Likewise, prior flu infection of CA-treated, AF-infected mice increased the pulmonary fungal burden from 27k to 80k median conidial equivalents. In contrast, mice not receiving CA treatment showed consistently low morbidity (median day-16 MSS = 0.5) and minimal fungal burden after AF challenge, regardless of prior flu infection.

Conclusion

We have established a model of PIA in CA-immunosuppressed mice that underscores the detrimental effect of corticosteroid therapy on the outcomes of PIA. In the future, we will employ this model to study the impact of various pharmacological interventions on the natural history of PIA in the background of corticosteroid immunosuppression.

Disclosures

Dimitrios P. Kontoyiannis, MD, Astellas (Consultant)Cidara Therapeutics (Advisor or Review Panel member)Gilead Sciences (Consultant, Grant/Research Support, Other Financial or Material Support, Honoraria)

710. Comparison of Initial CXR to CT in Patients (pts) with Hematologic Malignancy (HEM) and Documented Symptomatic Pulmonary Mucormycosis (PM)

Background

There is a spectrum of pulmonary disease burden in pts with HEM and PM. There have not been any data comparing the sensitivity and findings of initial Chest X-Ray (CXR) and chest CT in these pts.

Methods

We compared the findings of the initial CXR and CT in all pts with proven or probable PM via EORTC/MSG criteria. We included only pts who had pulmonary symptoms and who had both CXR and CT within 5 days of each other and within seven days of symptom onset or date of culture at MD Anderson Cancer Center from April 2000 and April 2020. We collected data regarding demographics, status of HEM, clinical presentation, frequency and findings of BAL and imaging findings, mold-active prophylaxis and treatment regimens, and mortality. CXR findings were classified as normal or abnormal, and if abnormal sub-classified as mass-like/consolidative, nodular, cavitary or heterogenous/non-specific. CT findings were classified in a similar manner.

Results

We Identified such 39 pts with PM who had both CXR and CT within 5 d. All pts had positive CT. Five pts (13%) had a negative CXR. The majority of pts 28 (72%) were neutropenic (neutrophil count &lt; 500). The most common CXR findings were consolidation or mass-like lesions (56%), followed by patchy, heterogenous or non-specific findings (33%) and nodules (13%). Only 3% had cavitary lesions. Similarly, consolidation or mass-like lesions were the most common finding on CT (69%), followed by nodular lesions with or without ground glass halos (56%). Cavitary lesions and/or reverse halo sign (RHS) were common (31%) on CT. Patients with normal CXR vs those with abnormal CXR were comparable in all clinical parameters we collected. The median survival from time of symptoms onset for all pts was 45 days. There was a trend for lower 42 day mortality in pts with normal CXR (20% vs 47%, P=.253).

Conclusion

A negative CXR does not preclude PM, especially in neutropenic pts. A CT is recommended for better sensitivity and although there was concordance in CXR with CT findings in some chest abnormalities (mass, consolidation), CT more commonly revealed nodules and signs highly suggestive of PM such as RHS. Although small numbers precluded a robust comparison, it is possible that HEM pts with PM and negative initial CXR have better prognosis, perhaps reflecting a lower burden of pulmonary involvement

Disclosures

Dimitrios P. Kontoyiannis, MD, Astellas (Consultant)Cidara Therapeutics (Advisor or Review Panel member)Gilead Sciences (Consultant, Grant/Research Support, Other Financial or Material Support, Honoraria)

1410. Isoniazid Therapy for Latent Tuberculosis Infection in Patients with Cancer Treated with Checkpoint Inhibitors Immunotherapy

Background

Data on the efficacy and tolerability of latent tuberculosis infection (LTBI) treatment in cancer patients receiving checkpoint inhibitor immunotherapy (CPI) is limited. We sought to assess LTBI therapy and its adverse events and outcomes in patients treated with CPI.

Methods

We performed a retrospective cohort study at MD Anderson Cancer Center of adult patients, between April 2016 and May 2021, who were receiving CPI and were diagnosed with LTBI based on positive T-SPOT TB test. We then compared those patients treated with isoniazid (INH) 5mg/kg daily versus those that did not receive INH therapy.

Results

We identified 35 patients treated with CPI who had a diagnosis of LTBI. Patients were divided into 2 groups: CPI alone (23 patients, 65.7%) and CPI+INH (12 patients, 34.3%). The majority of patients in both groups had renal cell carcinoma (34.3%) and melanoma (17.1%). Nivolumab as monotherapy was the most commonly used CPI agent in both groups (37.1%), whereas nivolumab and ipilimumab combination was mainly used in the CPI group (34.7%) compared to CPI+INH group (8.3%). In the CPI+INH group, 7 patients (58.3%) developed moderate to severe hepatoxicity that led to discontinuation of INH and CPI therapy versus none in the CPI group (p= 0.001). There was no statistically significant difference in the alanine aminotransferase (ALT) at baseline between both groups (p=0.117), whereas the median ALT level was significantly higher during CPI+INH therapy compared to CPI alone (135 U/L vs 24 U/L respectively, p=0.025. Furthermore, immune-related adverse events were reported in a total of 12 of 35 patients (34.2%). None of the patients in either group developed tuberculosis reactivation during a follow up period of up to 1148 days.

Conclusion

Our data suggest that latent tuberculosis reactivation is rare in cancer patients on CPI immunotherapy. Hepatotoxicity remains a concern in this patient population with LTBI treated with CPI and INH. With the widespread use of CPI, close laboratory and clinical monitoring is required to avoid life-threatening drug-induced liver injury and interruption of LTBI therapy and immunotherapy. Further clinical studies are warranted to determine the optimal management of LTBI during CPI therapy.

Disclosures

Pablo C. Okhuysen, MD, FACP, FIDSA, Deinove Pharmaceuticals (Grant/Research Support)Ferring Pharmaceuticals (Consultant)Melinta Therapeutics (Grant/Research Support)Merck & Co. (Grant/Research Support)Napo Pharmaceuticals (Consultant, Scientific Research Study Investigator, Research Grant or Support)Singulex (Consultant)Summit Therapeutics (Grant/Research Support) Dimitrios P. Kontoyiannis, MD, Astellas (Consultant)Cidara Therapeutics (Advisor or Review Panel member)Gilead Sciences (Consultant, Grant/Research Support, Other Financial or Material Support, Honoraria)