Antifungal Prophylaxis in Immunocompromised Patients

Overview of secondary immunodeficiency

In contrast to inborn errors of immunity (IEI), which are inherited disorders of the immune system that predispose to infections, malignancy, atopy, and immune dysregulation, secondary immunodeficiencies and immune dysregulation states (SID) are acquired impairments in immune cell function and/or regulation, and may be transient, reversible, or permanent. SIDs can derive from a variety of medical comorbidities, including protein-losing conditions, malnutrition, malignancy, certain genetic syndromes, prematurity, and chronic infections. Medications, including immunosuppressive and chemotherapeutic drugs, can have profound effects on immunity and biologic agents used in rheumatology, neurology, and hematology/oncology practice are increasingly common causes of SID. Iatrogenic factors, including surgical procedures (thymectomy, splenectomy) can also contribute to SID. A thorough case history, medication review, and laboratory evaluation are necessary to identify the primary driver and determine proper management of SID. Careful consideration should be given to whether a primary IEI could be contributing to autoimmunity, malignancy, and posttreatment complications (e.g., antibody deficiency). SID management consists of addressing the driving condition and/or removing the offending agent if feasible. If SID is suspected to be permanent, then antibiotic prophylaxis, additional immunization, and immunoglobulin replacement should be considered.

Fluconazole and levofloxacin prophylaxis are ineffective strategies for preventing infections in acute myeloid leukemia patients undergoing chemotherapy

INTRODUCTION

Acute myeloid leukemia patients are at high risk for infections, which contribute to increased mortality rates of up to 70%. The use of antimicrobial prophylaxis has been shown to significantly lower rates of infection. Therefore, this retrospective study aimed to evaluate the effect of two agents that showed effective results in the literature, levofloxacin and fluconazole, as prophylaxis strategies in AML patients.

METHODOLOGY

A total of 85 AML patients' medical records treated with a 7+3 induction chemotherapy protocol in the Cancer Hospital of Uberlândia from 2017 to 2021 were screened and their data was collected. Within these patients, groups for analysis were created based on whether the acting physician included an antibacterial or antifungal prophylaxis protocol during induction. Contingency tables with χ² and odds ratio tests were realized to verify associations between prophylaxis and infection. Additionally, Kaplan-Meier curves with Cox regression were developed to analyze survival.

RESULTS

The use of prophylaxis with either fluconazole or levofloxacin did not lower rates of infection, as those who with prophylaxis did not demonstrate significant differences when compared to those without (20.3-29.7%, and 12.3-23.3%, respectively). Patients who suffered a bacterial infection during induction were shown to have lower overall survival, with a similar trend seen in fungal infections.

CONCLUSION

Bacterial and fungal infections were associated with higher rates of induction mortality and lower overall survival, and prophylaxis using fluconazole and levofloxacin did not present any significant difference in preventing these infections in this study, contrasting results found in the literature. The individuality of each treatment center should be taken into consideration and future studies should be realized to better determine the most effective methods and agents for prophylaxis.

Navigating the Microbial Landscape: Understanding Dysbiosis in Human Genital Tracts and Its Impact on Fertility

Dysbiosis, an imbalance in microbial communities, significantly impacts the health and functionality of the human genital tract, with profound implications for fertility and reproductive health. This review explores the intricate relationship between genital tract microbiota and reproductive outcomes, highlighting the composition and dynamics of these microbial communities in both females and males. In females, the vaginal microbiota, primarily dominated by Lactobacillus species, is essential for maintaining a healthy vaginal environment, preventing infections, and supporting reproductive functions. In males, the genital microbiota influences sperm quality and reproductive health. Dysbiosis in the genital tract, manifesting as bacterial vaginosis, yeast infections, urethritis, or prostatitis, disrupts these microbial communities, leading to adverse reproductive outcomes such as infertility, pregnancy, and increased susceptibility to sexually transmitted infections. This review delves into the mechanisms through which dysbiosis affects fertility, including alterations in vaginal pH, mucosal immunity, inflammation, sperm viability, and motility. It also evaluates diagnostic methods, clinical implications, and management strategies, including probiotics, prebiotics, antibiotics, antifungal treatments, lifestyle interventions, and emerging therapeutic approaches. By understanding the microbial landscape of the genital tract and its impact on fertility, this review aims to inform targeted interventions that restore microbial balance and enhance reproductive health, ultimately improving fertility outcomes and the potential for healthy pregnancies.

The impact of antifungal prophylaxis in patients diagnosed with acute leukemias undergoing induction chemotherapy: a systematic review and meta-analysis

Acute leukemias are complex diseases to treat and have a high mortality rate. The immunosuppression caused by chemotherapy also causes the patient to become susceptible to a variety of infections, including invasive fungal infections. Protocols established in many countries attempt to prevent these infections through the use of pharmacological antifungal prophylaxis. This systematic review and meta-analysis investigates the existing evidence for the use of antifungal prophylaxis in patients undergoing induction chemotherapy for acute leukemia, and how prophylaxis can affect treatment response and mortality. Through the use of a population-variable-outcome strategy, keywords were utilized to search online databases. The included studies were selected and the data was collected to develop descriptive results for all studies, and, for studies that met the criteria, a meta-analysis of the Relative Risk (RR) was analyzed for infection rates, in-hospital mortality, and complete remission. A total of 33 studies were included in this systematic review, with most studies presenting positive results (n = 28/33) from the use of antifungal prophylaxis. Using a random effects model, the pooled results of the meta-analysis presented lower invasive fungal infections in AML (RR: 0.527 (95% CI: 0.391; 0.709). p < 0.001). p < 0.001) and ALL (RR: 0.753 (95% CI: 0.574; 0.988). p = 0.041). when antifungal prophylaxis was used. No discernible difference was encountered in the rate of complete remission when using prophylaxis. Antifungal prophylaxis provides a lower risk of invasive fungal infections and in-hospital mortality in acute leukemia patients undergoing induction chemotherapy.

Using Behavior Change Theory to Identify Drivers and Barriers for Antifungal Treatment Decisions: A Case Study in a Large Teaching Hospital in the East of England, UK

INTRODUCTION

Antifungal stewardship (AFS) programs are recognized to contribute to optimizing antifungal prescribing for treatment and prophylaxis. However, only a small number of such programs are implemented. Consequently, evidence on behavioral drivers and barriers of such programs and learnings from existing successful AFS programs is limited. This study aimed to leverage a large AFS program in the UK and derive learnings from it. The objective was to (a) investigate the impact of the AFS program on prescribing habits, (a) use a Theoretical Domains Framework (TDF) based on the COM-B (Capability, Opportunity, and Motivation for Behavior) to qualitatively identify drivers and barriers for antifungal prescribing behaviors across multiple specialties, and (c) semiquantitatively investigate trends in antifungal prescribing habits over the last 5 years.

METHODS

Qualitative interviews and a semiquantitative online survey were conducted across hematology, intensive care, respiratory, and solid organ transplant clinicians at Cambridge University Hospital. The discussion guide and survey used were developed to identify drivers of prescribing behavior, based on the TDF.

RESULTS

Responses were received from 21/25 clinicians. Qualitative outcomes demonstrated that the AFS program was effective in supporting optimal antifungal prescribing practices. We found seven TDF domains influencing antifungal prescribing decisions-five drivers and two barriers. The key driver was collective decision-making among the multidisciplinary team (MDT) while key barriers were lack of access to certain therapies and fungal diagnostic capabilities. Furthermore, over the last 5 years and across specialties, we observed an increasing tendency for prescribing to focus on more targeted rather than broad-spectrum antifungals.

CONCLUSIONS

Understanding the basis for linked clinicians' prescribing behaviors for identified drivers and barriers may inform interventions on AFS programs and contribute to consistently improving antifungal prescribing. Collective decision-making among the MDT may be leveraged to improve clinicians' antifungal prescribing. These findings may be generalized across specialty care settings.

Metagenomic Next-Generation Sequencing in the Diagnosis of Infectious Fever During Myelosuppression Among Pediatric Patients with Hematological and Neoplastic Diseases

Purpose

To analyze the contribution of metagenomic next-generation sequencing (mNGS) in the guidance of clinical treatment and outcomes of infection during myelosuppression among children with hematological and neoplastic diseases.

Patients and Methods

The clinical data and results of mNGS assay of febrile patients suspected of infection were retrospectively collected. The characteristics of pathogenic microorganisms and clinical course of myelosuppressed children with hematological diseases were summarized.

Results

Our study included 70 patients (45 males) with a median age of 5 years (range: 0.5 to 13 y). During the study period, there were 96 events of suspected infection. According to comprehensive clinical diagnosis, 73 blood infections, 43 pneumonia and 2 urinary tract infections occurred. The positive rate of mNGS was significantly higher than that of traditional microbial detection (83.3% vs 17.7%). The main pathogens detected by mNGS were Pseudomonas aeruginosa, Acinetobacter, human herpesvirus, Candida and Aspergillus. The average duration of fever was 4.9 days and 11.6 days (P < 0.05), and the average cost of anti-infection treatment was RMB ¥28,077 and 39,898 (P < 0.05) among children received mNGS within 48 hours and more than 48 hours after the onset of infection symptoms.

Conclusion

mNGS contributes to clinical management of children with infection during myelosuppression, especially among patients with negative traditional microbial detection. Early implementation of mNGS in children with symptoms has a tendency to reduce the time of infection, fever and the cost of treatment.

Prevalence and Healthcare Burden of Fungal Infections in the United States, 2018

Background

Fungal infections are responsible for >1.5 million deaths globally per year, primarily in those with compromised immune function. This is concerning as the number of immunocompromised patients, especially in those without human immunodeficiency virus (HIV), has risen in the past decade. The purpose of this analysis was to provide the current prevalence and impact of fungal disease in the United States.

Methods

We analyzed hospital discharge data from the most recent (2018) Healthcare Cost and Utilization Project National Inpatient Sample, and outpatient visit data from the National Ambulatory Medical Care Survey and the National Hospital Ambulatory Medical Care Survey. Costs are presented in 2018 United States (US) dollars.

Results

In the 35.5 million inpatient visits documented in 2018 in the US, approximately 666 235 fungal infections were diagnosed, with an estimated attributable cost of $6.7 billion. Aspergillus, Pneumocystis, and Candida infections accounted for 76.3% of fungal infections diagnosed, and 81.1% of associated costs. Most fungal disease occurred in patients with elevated risk of infection. The visit costs, lengths of stay, and risks of mortality in this population were more than twice that of those without fungal diagnoses. A further 6.6 million fungal infections were diagnosed during outpatient visits.

Conclusions

Fungal disease is a serious clinical concern with substantial healthcare costs and significant increases in morbidity and mortality, particularly among predisposed patients. Increased surveillance, standardized treatment guidelines, and improvement in diagnostics and therapeutics are needed to support the rising numbers of at-risk patients.

Clinical assessment of the utility of metagenomic next-generation sequencing in pediatric patients of hematology department

INTRODUCTION

Metagenomic Next-Generation Sequencing (mNGS) is an emerging technique for microbial identification and diagnosis of infectious diseases. The clinical utility of mNGS, especially its real-world impact on antimicrobial treatment and patient outcome has not been systematically evaluated.

METHODS

We prospectively assessed the effectiveness of mNGS in 70 febrile inpatients with suspected infections at Hematology department of the Children's Hospital, National Clinical Research Center for Child Health. 69/70 patients were given empirical antibiotics prior to mNGS. A total of 104 samples (62 plasma, 34 throat swabs, 4 bone marrow, 4 bronchoalveolar lavage) were collected on day 1-28 (mean 6.9) following symptom onset and underwent mNGS testing.

RESULTS

Traditional microbiological tests discovered causal microorganisms in 5/70 (7.14%) patients, which were also detected by mNGS. In addition, mNGS reported possible pathogens when routine tests were negative. Antibiotics were adjusted accordingly in 55/70 (78.6%) patients that led to improvement/relief of symptoms within 3 days. In contrast, mNGS results were considered irrelevant in 15/70 (21.4%) patients by a board of clinicians, based on biochemical, serological, imaging evidence, and experiences.

CONCLUSION

mNGS expanded the capacity of pathogen detection and made a positive impact on clinical management of suspected infections through (a) differential diagnosis which may rule out infectious diseases and (b) adjustment or de-escalation of empirical antibiotics.

Inhaled Amphotericin B as Aspergillosis Prophylaxis in Hematologic Disease: An Update

This review summarizes the literature on inhaled amphotericin B for invasive aspergillosis prophylaxis in patients with neutropenia secondary to hematologic malignancy treatment or stem cell transplant. Six trials, 2 randomized controlled and 4 with historical controls, were identified. Three inhaled amphotericin B deoxycholate trials found a reduced invasive aspergillosis incidence, 1 reaching statistical significance. Three inhaled liposomal amphotericin B trials demonstrated similar reductions with 2 finding statistical significance. Relative risk reductions for invasive aspergillosis were routinely 40-60%. Both formulations were without reported systemic or severe adverse effects. The most common adverse events were cough, bad taste, and nausea. Discontinuation rates ranged from 0-45%. The only randomized, placebo-controlled trial utilized inhaled liposomal amphotericin B reported a nearly 60% relative risk reduction.

Inhaled liposomal amphotericin B 12.5 mg twice weekly is an alternative for invasive aspergillosis prophylaxis in high risk neutropenic patients with hematologic malignancies and stem cell transplant recipients when recommended azole agents are contraindicated or should not be used.

Population Pharmacokinetic Study of Prophylactic Fluconazole in Preterm Infants for Prevention of Invasive Candidiasis

Fluconazole is an antifungal agent with reported evidence for its prophylactic effect against systemic fungal infection in preterm infants. The aim of this study was to build a population pharmacokinetic model to evaluate the pharmacokinetic characteristics of intravenous and oral fluconazole in preterm infants with the current prophylactic fluconazole dosing regimen. A pharmacokinetic model was developed using 301 fluconazole concentrations from 75 preterm infants with a baseline body weight (WT) ranging from 0.5 to 1.5 kg and an estimated glomerular filtration rate (eGFR) ranging from 12.9 to 58.5 ml/min/1.73 m² Eligible infants received an intravenous or oral dose of 3 mg/kg of body weight of fluconazole, twice weekly with a ≥72-h dose interval, for 4 weeks. The model was qualified with basic goodness-of-fit diagnostics, visual predictive checks, and bootstrapping. The fluconazole pharmacokinetics was well described with a one-compartment linear model with a proportional residual error. The population clearance (CL) and volume of distribution (V) were derived as 0.0197 × (WT/1.00)^0.746 × (eGFR/25.0)^0.463 × exp(η) and 1.04 × WT × exp(η), respectively. Such covariate analyses augment the awareness of the need for personalized dosing in preterm infants. (This study has been registered at ClinicalTrials.gov under identifier NCT01683760).

Micafungin prophylaxis for acute leukemia patients undergoing induction chemotherapy

Background

Micafungin is a well-tolerated and effective prophylactic antifungal agent used in hematologic diseases. In this prospective trial, we evaluated the efficacy and safety of prophylactic micafungin during first induction chemotherapy in patients with acute leukemia. We also compared outcomes of prophylactic micafungin with those of prophylactic posaconazole in acute myeloid leukemia (AML).

Methods

Medically fit patients with newly diagnosed acute leukemia received 50 mg micafungin intravenously once daily from the initiation of first induction chemotherapy to recovery of neutrophil count, suspected fungal infection, or unacceptable drug-related toxicity (Clinicaltrials.gov number, NCT02440178). The primary end point was incidence of invasive fungal infection, and the secondary end points were adverse events of prophylactic micafungin and mortality during induction therapy.

Results

The 65 patients (median age = 51 years, male:female = 34:31) enrolled in this study had diagnoses of AML (33, 50.8%), acute lymphoblastic leukemia (31, 47.7%), and acute biphenotypic leukemia (1, 1.5%). Median duration of micafungin treatment was 24 days (range 1–68), with proven invasive fungal disease in one patient (1.5%) and possible fungal infection in two patients (3.1%). Three of the patients (4.6%) experienced the following adverse events, but all events were tolerable: liver function abnormality (Grade 2, n = 1; Grade 3, n = 1) and allergic reaction (Grade 2, n = 1). Three patients died during induction therapy, and invasive aspergillosis pneumonia was the cause of death for one of those patients. Overall, 19 patients (29.2%) discontinued prophylactic micafungin, and 18 (27.7%) patients switched to another antifungal agent. We observed no fungal infections caused by amphotericin B-resistant organisms. In AML patients, outcomes of prophylactic micafungin during induction chemotherapy did not differ significantly with those of prophylactic posaconazole with regard to incidence of fungal infections, rate of discontinuation, or safety.

Conclusions

Our study demonstrates that prophylactic micafungin is safe and effective in patients with acute leukemia undergoing induction chemotherapy. Outcomes in patients with AML were similar to those of prophylactic posaconazole, indicating the usefulness of micafungin as a prophylactic antifungal agent during induction chemotherapy for AML.

Trial registration

Clinicaltrials.gov NCT02440178, registered May 12th 2015.

Incidence and Risk Factors for Breakthrough Invasive Mold Infections in Acute Myeloid Leukemia Patients Receiving Remission Induction Chemotherapy

Background

Despite fungal prophylaxis, invasive mold infections (IMIs) are a significant cause of morbidity and mortality in patients with acute myeloid leukemia (AML) receiving remission induction chemotherapy. The choice of antifungal prophylaxis agent remains controversial, especially in the era of novel targeted therapies. We conducted a retrospective case–control study to determine the incidence of fungal infections and to identify risk factors associated with IMI.

Methods

Adult patients with AML receiving anti-Aspergillus prophylaxis were included to determine the incidence of IMI per 1000 prophylaxis-days. Patients without and with IMI were matched 2:1 based on the day of IMI diagnosis, and multivariable models using logistic regression were constructed to identify risk factors for IMI.

Results

Of the 162 included patients, 28 patients had a possible (n = 22), probable, or proven (n = 6) diagnosis of IMI. The incidence of proven or probable IMI per 1000 prophylaxis-days was not statistically different between anti-Aspergillus azoles and micafungin (1.6 vs 5.4, P = .11). The duration of prophylaxis with each agent did not predict IMI occurrence on regression analysis. Older age (odds ratio [OR], 1.04; 95% confidence interval [CI], 1.004–1.081; P = .03) and relapsed/refractory AML diagnosis (OR, 4.44; 95% CI, 1.56–12.64; P = .003) were associated with IMI on multivariable analysis.

Conclusions

In cases that preclude use of anti-Aspergillus azoles for prophylaxis, micafungin 100 mg once daily may be considered; however, in older patients and those with relapsed/refractory disease, diligent monitoring for IMI is required, irrespective of the agent used for antifungal prophylaxis.

Polymorphisms in Receptors Involved in Opsonic and Nonopsonic Phagocytosis, and Correlation with Risk of Infection in Oncohematology Patients

High-risk hematological malignancies are a privileged setting for infection by opportunistic microbes, with invasive mycosis being one of the most serious complications. Recently, genetic background has emerged as an unanticipated risk factor. For this reason, polymorphisms for genes encoding archetypal receptors involved in the opsonic and nonopsonic clearance of microbes, pentraxin-3 (PTX3) and Dectin-1, respectively, were studied and correlated with the risk of infection. Fungal, bacterial, and viral infections were registered for a group of 198 patients with high-risk hematological malignancies. Polymorphisms for the pentraxin-3 gene (PTX3) showed a significant association with the risk of fungal infection by Candida spp. and, especially, by Aspergillus spp. This link remained even for patients undergoing antifungal prophylaxis, thus demonstrating the clinical relevance of PTX3 in the defense against fungi. CLEC7A polymorphisms did not show any definite correlation with the risk of invasive mycosis, nor did they influence the expression of Dectin-1 isoforms generated by alternative splicing. The PTX3 mRNA expression level was significantly lower in samples from healthy volunteers who showed these polymorphisms, although no differences were observed in the extents of induction elicited by bacterial lipopolysaccharide and heat-killed Candida albicans, thus suggesting that the expression of PTX3 at the start of infection may influence the clinical outcome. PTX3 mRNA expression can be a good biomarker to establish proper antifungal prophylaxis in immunodepressed patients.

Synergistic and antagonistic effects of immunomodulatory drugs on the action of antifungals against Candida glabrata and Saccharomyces cerevisiae

Candidemia and other forms of invasive fungal infections caused by Candida glabrata and to a lesser extent Saccharomyces cerevisiae are a serious health problem, especially if their steadily rising resistance to the limited range of antifungal drugs is taken into consideration. Various drug combinations are an attractive solution to the resistance problem, and some drug combinations are already common in the clinical environment due to the nature of diseases or therapies. We tested a few of the common antifungal-immunomodulatory drug combinations and evaluated their effect on selected strains of C. glabrata and S. cerevisiae. The combinations were performed using the checkerboard microdilution assay and interpreted using the Loewe additivity model and a model based on the Bliss independence criterion. A synergistic interaction was confirmed between calcineurin inhibitors (Fk506 and cyclosporine A) and antifungals (fluconazole, itraconazole, and amphotericin B). A new antagonistic interaction between mycophenolic acid (MPA) and azole antifungals was discovered in non-resistant strains. A possible mechanism that explains this is induction of the Cdr1 efflux pump by MPA in C. glabrata ATCC 2001. The Pdr1 regulatory cascade plays a role in overall resistance to fluconazole, but it is not essential for the antagonistic interaction. This was confirmed by the Cgpdr1Δ mutant still displaying the antagonistic interaction between the drugs, although at lower concentrations of fluconazole. This antagonism calls into question the use of simultaneous therapy with MPA and azoles in the clinical environment.

Liver fungal infections: an overview of the etiology and epidemiology in patients affected or not affected by oncohematologic malignancies

Fungal infections of the liver, most commonly caused by Candida spp., often occur in patients with hematologic malignancies treated with chemotherapy. Colonization of the gastrointestinal tract is thought to be the main origin of dissemination of Candida; mucositis and neutropenia facilitate the spread of Candida from the gastrointestinal tract to the liver. Hepatic involvement due to other fungi is a less common infectious complication in this setting. Fungal infections represent a less common cause of hepatic abscesses in non-oncohematologic population and the trend appears to be decreasing in recent years. Understanding of the etiology and epidemiology of fungal infections of the liver is indicated for an appropriate antimicrobial therapy and an overall optimal management of fungal liver infections.