Diagnostic Utility of Galactomannan Enzyme Immunoassay in Invasive Aspergillosis in Pediatric patients with Hematological Malignancy

OBJECTIVE

This study aims to determine the diagnostic utility of galactomannan enzyme immunoassay (GM EIA) in invasive aspergillosis (IA) in children with hematological malignancy (high risk population) in terms of sensitivity, specificity, negative predictive value (NPV) and positive predictive values (PPV) at various cut offs while validating the revised EORTC/MSG 2019 criteria in order to obtain the best cut-off.

MATERIAL AND METHODS

For 100 pediatric patients, serum and respiratory samples were collected. Clinical, mycological workup (potassium-hydroxide mount, fungal culture) and GM EIA was done to classify proven, probable, and possible IA as per EORTC-MSG guidelines,2019. Sensitivity, specificity, PPV and NPV were calculated of GM indices at cut-off 0.5, 0.7 and 1, and validated with revised EORTC -MSG, 2019.

RESULTS

Of 100 patients enrolled, 75 were diagnosed with ALL, 14 with AML, two with Hodgkin's, three had non-Hodgkin lymphoma, and six had undifferentiated leukemia. With routine mycological findings, 51 were classified as probable IA, 11 as possible IA, and 38 as no IA. Aspergillus flavus was the most prevalent on culture (56.9%, 29/51) followed by A. fumigatus (29%, 15/51) A. niger (7.8%, 4/51), A. terreus (3.9%, 2/51) and A. nidulans (2%, 1/51). GM EIA demonstrated sensitivity 82.3%, specificity 97.4%, PPV 98.1%, and NPV 77.1% at cut-off 0.67 when comparing probable/possible IA v/s no IA groups. The GM EIA had the best sensitivity (82.4%), specificity (81.8%), PPV (95.5%), and NPV (50%) at cut off 0.78 when the probable IA group was compared to the possible IA. Seven patients succumbed of whom 5 had GMI ≥ 2.

CONCLUSION

This study deduces the optimal cut-off for serum GM EIA to be 0.67 obtained by ROC analysis when comparing possible and probable IA versus no IA and reinforces the definition of probable category of EORTC-MSG criteria, 2019. At 0.5 ODI the sensitivity (87.1%) and NPV (80.5%) are high, thus making it the most suitable cut-off for detecting true positive and ruling out IA respectively, in pediatric patients with hematological malignancy. GM EIA when performed adjunctive to clinico-radiological findings can prove to be screening, diagnostic and prognostic test for IA in pediatric hematological malignancy patients.

Conference Report 33rd European Congress on Clinical Microbiology and Infectious Diseases (ECCMID): New developments in pediatric oncology infectious disease supportive care

Infections continue to be major causes of morbidity and mortality in immunocompromised children and adolescents with cancer or undergoing allogeneic hematopoietic cell transplantation. This report summarizes new clinical research data presented at the 33rd European Congress on Clinical Microbiology and Infectious Diseases on infections in this vulnerable population, with a focus on the epidemiology, diagnosis, and prevention of invasive fungal diseases and de-escalation strategies in neutropenic patients with fever of unknown origin.

Long-Term Kinetics of Serum Galactomannan during Treatment of Complicated Invasive Pulmonary Aspergillosis

Several studies have evaluated the serum galactomannan (GM) antigen assay in pediatric patients, and there is convincing evidence for its usefulness as a diagnostic tool for invasive Aspergillus infections in patients with acute leukemias or post allogeneic hematopoietic cell transplantation (HCT). Less is known about the utility of the assay in monitoring responses to treatment in patients with established invasive aspergillosis (IA). Here, we present the long-term kinetics of serum galactomannan in two severely immunocompromised adolescents with invasive pulmonary aspergillosis (IPA) who were cured after complicated clinical courses. We also review the utility of the GM antigen assay in serum as a prognostic tool around the time of diagnosis of IA and as a biomarker to monitor disease activity in patients with established IA and assess responses to systemic antifungal therapy.

Pediatric Invasive Aspergillosis: A Retrospective Review of 59 Cases

Invasive aspergillosis (IA) is a major cause of morbidity and mortality. This study aimed to present our 10-year IA experience at a single center. Fifty-nine pediatric patients with IA were included in this study. The male-to-female ratio was 42/17. The median age was 8.75 years. Hematologic malignancy was present in the majority of the patients (40/59, 68%). The mean neutropenia duration was 18.5 days. Cytosine arabinoside was the most common immunosuppressive therapy directed at T cells during IA diagnosis. IA cases were categorized as proven (27%), probable (51%), or possible (22%) according to the 2008 European Organization for Research and Treatment of Cancer/Invasive Fungal Infections Cooperative Group and the National Institute of Allergy and Infectious Diseases Mycoses Study Group (EORTC/MSG) criteria. The lungs (78%) were the most common site of IA, and nodules were the most frequent radiological findings (75.5%). In 38 patients (64.4%) receiving antifungal prophylaxis, prophylactic agents included fluconazole (30.5%), liposomal amphotericin B (23.7%), posaconazole (8.5%), and voriconazole (1.7%). Initial treatment was most commonly administered as monotherapy (69.5%). The median antifungal treatment duration was 67 days. Eleven deaths (18.6%) were due to aspergillosis. With the increased use of corticosteroids, biological agents, and intensive immunosuppressive chemotherapy, IA will most likely continue to occur frequently in pediatric patients.

Epidemiology and outcomes of invasive aspergillosis among pediatric immunocompromised patients: a 12-year single-center experience

Invasive aspergillosis (IA) remains a common cause of mortality in pediatric immunocompromised populations. Much of our knowledge of IA stems from adult literature. We conducted a retrospective evaluation of cases of proven or probable IA, defined according to the 2019 EORTC/MSG criteria, in patients with underlying immunocompromising conditions at Boston Children's Hospital from January 1, 2007 to January 1, 2019. We estimated survival curves over 12 weeks using the Kaplan-Meier method for all-cause mortality, and we used univariate Cox proportional hazards modeling to evaluate for mortality risk factors. We identified 59 cases, 29% with proven and 71% with probable IA. Pulmonary IA was the most common presentation (78%). The median age at diagnosis was 11 years (range, 0.5-28). Hematopoietic cell transplantation (HCT) was the most frequent predisposing underlying condition (41%). Among affected patients, 44.8% were neutropenic and 59.3% were lymphopenic at diagnosis. The 12-week all-cause mortality rate was 25.4%; HCT recipients comprised the majority of deaths (9/15) with a hazard ratio of 2.47 [95% CI, 0.87-6.95]. No patients with congenital immunodeficiencies (n = 8) died within 12 weeks of IA diagnosis. Other risk factors that were significantly associated with mortality included mechanical ventilation at diagnosis, intensive care unit stay, and lymphopenia; treatment with an Aspergillus-active azole was associated with decreased mortality. In conclusion, our study found that in pediatric immunocompromised hosts, IA is associated with a high 12-week all-cause mortality rate, with a particular impact on the HCT population.

Pediatric Lower Respiratory Tract Infections: Imaging Guidelines and Recommendations

Lower respiratory tract infection (LRTI) remains a major cause of morbidity and mortality in children. Various organisms cause LRTI, including viruses, bacteria, fungi, and parasites, among others. Infections caused by 2 or more organisms also occur, sometimes enhancing the severity of the infection. Medical imaging helps confirm a diagnosis but also plays a role in the evaluation of acute and chronic sequelae. Medical imaging tests help evaluate underlying pathology in pediatric patients with recurrent or long-standing symptoms as well as the immunocompromised.

Invasive fungal infections in a pediatric hematology-oncology department: A 16-year retrospective study

Background and Purpose

Invasive fungal infections (IFIs) are a major cause of morbidity and mortality in immunocompromised children. The purpose of our study was to evaluate the incidence of IFIs in pediatric patients with underlying hematologic malignancies and determine the patient characteristics, predisposing factors, diagnosis, treatment efficacy, and outcome of IFIs.

Materials and Methods

For the purpose of the study, a retrospective analysis was performed on cases with proven and probable fungal infections from January 2001 to December 2016 (16 years).

Results

During this period, 297 children with hematologic malignancies were admitted to the 2nd Pediatric Department of Aristotle University of Thessaloniki, Greece, and 24 cases of IFIs were registered. The most common underlying diseases were acute lymphoblastic leukemia (ALL; n=19,79%), followed by acute myeloid leukemia (AML; n=4, 17%) and non-Hodgkin lymphoma (NHL; n=1,4%). The crude incidence rates of IFIs in ALL, AML, and NHL were 10.5%, 18.2%, and 2.8% respectively. Based on the results, 25% (n=6) and 75% (n=18) of the patients were diagnosed as proven and probable IFI cases, respectively. The lung was the most common site of involvement in 16 (66.7%) cases. Furthermore, Aspergillus and Candida species represented 58.3% and 29.1% of the identified species, respectively. Regarding antifungal treatment, liposomal amphotericin B was the most commonly prescribed therapeutic agent (n=21), followed by voriconazole (n=9), caspofungin (n=3), posaconazole (n=3), micafungin (n=1), and fluconazole (n=1). In addition, 12 children received combined antifungal treatment. The crude mortality rate was obtained as 33.3%.

Conclusion

As the findings of the present study indicated, despite the progress in the diagnosis and treatment of IFIs with the use of new antifungal agents, the mortality rate of these infections still remains high.

Fungal infections in primary immunodeficiency diseases

Primary immunodeficiency diseases (PID), encompass a heterogeneous group of diseases, with increased susceptibility to recurrent, severe infections. Invasive fungal infections raise a serious concern related to their morbidity and mortality. Herein, we describe various fungal infections among different PID patients. Twenty-eight PID patients diagnosed with fungal infections were included; fourteen patients with chronic granulomatous disease, two with Hyper Immunoglobulin E syndrome, one with LRBA deficiency and one with MHC class II defect, one with unclassified immune dysregulation, one with CD4 lymphopenia and one patient with Immune dysregulation Polyendocrinopathy Enteropathy X-linked syndrome. Aspergillus species were the most common isolated causative organisms in 78% of patients, Candida species were the causative organisms in 32%, Pneumocystis jirovecii caused infections in 7% followed by Malassezia furfur, Fusarium spp., Mucormycosis, and Penicillium chrysogenium 3.5% for each. The mortality rate among our patients was 10/28 (35.7%). PID patients are at high risk of developing fungal infections.

A non-randomized trial to assess the safety, tolerability, and pharmacokinetics of posaconazole oral suspension in immunocompromised children with neutropenia

Background

Posaconazole (POS) is a potent triazole antifungal agent approved in adults for treatment and prophylaxis of invasive fungal infections (IFIs). The objectives of this study were to evaluate the pharmacokinetics (PK), safety, and tolerability of POS oral suspension in pediatric subjects with neutropenia.

Methods

This was a prospective, multicenter, sequential dose-escalation study. Enrolled subjects were divided into 3 age groups: AG1, 7 to <18 years; AG2, 2 to <7 years; and AG3, 3 months to <2 years. AG1 and AG2 were divided into 3 dosage cohorts: DC1, 12 mg/kg/day divided twice daily (BID); DC2, 18 mg/kg/day BID; and DC3, 18 mg/kg/day divided thrice daily (TID). AG3 was also divided into DC1 and DC2; however, no subjects were enrolled in DC2. Subjects received 7–28 days of POS oral suspension. PK samples were collected at predefined time points. The POS PK target was predefined as ~90% of subjects with C_avg (AUC /dosing interval) between 500 and 2500 ng/mL, with an anticipated mean steady state C_avg exposure of ~1200 ng/mL.

Results

The percentage of subjects meeting the PK target was <90% across all age groups and dosage cohorts (range: 31% to 80%). The percentage of subjects that achieved the C_avg target of 500 to 2500 ng/mL on Day 7 ranged from 31% to 80%, with the lowest proportion in subjects 2 to <7 years receiving 12 mg/kg/day BID (AG2/DC1) and the highest proportion in subjects 7 to <18 years receiving 18 mg/kg/day TID (AG1/DC3). At all three dose levels (12 mg/kg/day BID, 18 mg/kg/day BID and 18 mg/kg/day TID), subjects in AG1 (7 to <18 years old) had higher mean PK exposures at steady state than those in AG2. High variability in exposures was observed in all groups. POS oral suspension was generally well tolerated and most of the reported adverse events were related to the subjects’ underlying diseases.

Conclusion

The POS PK target of 90% of subjects with C_avg between 500 and 2500 ng/mL was not achieved in any of the age groups across the different dosage cohorts. New formulations of the molecule with a greater potential to achieve the established PK target are currently under investigation.

Trial registration

ClinicalTrials.gov identifier: NCT01716234

Invasive Aspergillosis in Pediatric Leukemia Patients: Prevention and Treatment

The purpose of this article is to review and update the strategies for prevention and treatment of invasive aspergillosis (IA) in pediatric patients with leukemia and in patients with hematopoietic stem cell transplantation. The major risk factors associated with IA will be described since their recognition constitutes the first step of prevention. The latter is further analyzed into chemoprophylaxis and non-pharmacologic approaches. Triazoles are the mainstay of anti-fungal prophylaxis while the other measures revolve around reducing exposure to mold spores. Three levels of treatment have been identified: (a) empiric, (b) pre-emptive, and (c) targeted treatment. Empiric is initiated in febrile neutropenic patients and uses mainly caspofungin and liposomal amphotericin B (LAMB). Pre-emptive is a diagnostic driven approach attempting to reduce unnecessary use of anti-fungals. Treatment targeted at proven or probable IA is age-dependent, with voriconazole and LAMB being the cornerstones in >2yrs and <2yrs age groups, respectively.

Invasive Aspergillosis in Children: Update on Current Guidelines

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

Methods of Controlling Invasive Fungal Infections Using CD8+ T Cells

Invasive fungal infections (IFIs) cause high rates of morbidity and mortality in immunocompromised patients. Pattern-recognition receptors present on the surfaces of innate immune cells recognize fungal pathogens and activate the first line of defense against fungal infection. The second line of defense is the adaptive immune system which involves mainly CD4+ T cells, while CD8+ T cells also play a role. CD8+ T cell-based vaccines designed to prevent IFIs are currently being investigated in clinical trials, their use could play an especially important role in acquired immune deficiency syndrome patients. So far, none of the vaccines used to treat IFI have been approved by the FDA. Here, we review current and future antifungal immunotherapy strategies involving CD8+ T cells. We highlight recent advances in the use of T cells engineered using a Sleeping Beauty vector to treat IFIs. Recent clinical trials using chimeric antigen receptor (CAR) T-cell therapy to treat patients with leukemia have shown very promising results. We hypothesized that CAR T cells could also be used to control IFI. Therefore, we designed a CAR that targets β-glucan, a sugar molecule found in most of the fungal cell walls, using the extracellular domain of Dectin-1, which binds to β-glucan. Mice treated with D-CAR+ T cells displayed reductions in hyphal growth of Aspergillus compared to the untreated group. Patients suffering from IFIs due to primary immunodeficiency, secondary immunodeficiency (e.g., HIV), or hematopoietic transplant patients may benefit from bioengineered CAR T cell therapy.

Recognition and Clinical Presentation of Invasive Fungal Disease in Neonates and Children

Invasive fungal diseases (IFDs) are devastating opportunistic infections that result in significant morbidity and death in a broad range of pediatric patients, particularly those with a compromised immune system. Recognizing them can be difficult, because nonspecific clinical signs and symptoms or isolated fever are frequently the only presenting features. Therefore, a high index of clinical suspicion is necessary in patients at increased risk of IFD, which requires knowledge of the pediatric patient population at risk, additional predisposing factors within this population, and the clinical signs and symptoms of IFD. With this review, we aim to summarize current knowledge regarding the recognition and clinical presentation of IFD in neonates and children.

Diagnostic Imaging and Invasive Fungal Diseases in Children

Invasive fungal disease (IFD) is a life-threatening condition, especially in immunocompromised children. The role of diagnostic imaging in children at risk for an IFD is multifactorial, including initially detecting it, evaluating for dissemination of infection beyond the primary site of disease, monitoring the response to antifungal therapy, and assessing for potential relapse. The objective of this review was to synthesize the published literature relevant to the use of various imaging modalities for the diagnosis and management of IFD in children.

Fungal infections of the lung in children

Fungal infections of the lungs are relatively common and potentially life-threatening conditions in immunocompromised children. The role of imaging in children with lung mycosis is to delineate the extension of pulmonary involvement, to assess response to therapy, and to monitor for adverse sequelae such as bronchiectasis and cavitation. The aim of this paper is to show imaging findings in a series of patients with fungal pneumonia from two tertiary children's hospitals, to discuss differential diagnoses and to show how imaging findings can vary depending on the host immune response.

Identification of New Antifungal Compounds Targeting Thioredoxin Reductase of Paracoccidioides Genus

The prevalence of invasive fungal infections worldwide has increased in the last decades. The development of specific drugs targeting pathogenic fungi without producing collateral damage to mammalian cells is a daunting pharmacological challenge. Indeed, many of the toxicities and drug interactions observed with contemporary antifungal therapies can be attributed to “nonselective” interactions with enzymes or cell membrane systems found in mammalian host cells. A computer-aided screening strategy against the TRR1 protein of Paracoccidioides lutzii is presented here. Initially, a bank of commercially available compounds from Life Chemicals provider was docked to model by virtual screening simulations. The small molecules that interact with the model were ranked and, among the best hits, twelve compounds out of 3,000 commercially-available candidates were selected. These molecules were synthesized for validation and in vitro antifungal activity assays for Paracoccidioides lutzii and P. brasiliensis were performed. From 12 molecules tested, 3 harbor inhibitory activity in antifungal assays against the two pathogenic fungi. Corroborating these findings, the molecules have inhibitory activity against the purified recombinant enzyme TRR1 in biochemical assays. Therefore, a rational combination of molecular modeling simulations and virtual screening of new drugs has provided a cost-effective solution to an early-stage medicinal challenge. These results provide a promising technique to the development of new and innovative drugs.

Pediatric foreign body aspiration: A nidus for Aspergillus colonization

We describe an immunocompetent child with bronchial fungus following foreign body aspiration. A two-year-old male presented with cough. Workup revealed air trapping and bronchoscopy showed aspirated foreign material in the right mainstem bronchus. Histopathology revealed fungal organisms suggestive of Aspergillus within an ulcer of the adjacent bronchial mucosa. Foreign body aspiration has been posited as a nidus for aspergilloma formation but is not yet described in the available English-language pediatric literature. Here, the foreign body provided a site for fungal growth in the bronchus of an otherwise healthy child. This case suggests that bronchial foreign body may pose risk of fungal colonization even in immunocompetent children.

Fourth European Conference on Infections in Leukaemia (ECIL-4): guidelines for diagnosis, prevention, and treatment of invasive fungal diseases in paediatric patients with cancer or allogeneic haemopoietic stem-cell transplantation

Invasive opportunistic fungal diseases (IFDs) are important causes of morbidity and mortality in paediatric patients with cancer and those who have had an allogeneic haemopoietic stem-cell transplantation (HSCT). Apart from differences in underlying disorders and comorbidities relative to those of adults, IFDs in infants, children, and adolescents are unique with respect to their epidemiology, the usefulness of diagnostic methods, the pharmacology and dosing of antifungal agents, and the absence of interventional phase 3 clinical trials for guidance of evidence-based decisions. To better define the state of knowledge on IFDs in paediatric patients with cancer and allogeneic HSCT and to improve IFD diagnosis, prevention, and management, the Fourth European Conference on Infections in Leukaemia (ECIL-4) in 2011 convened a group that reviewed the scientific literature on IFDs and graded the available quality of evidence according to the Infectious Diseases Society of America grading system. The final considerations and recommendations of the group are summarised in this manuscript.

Infektionen

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