Aspergillus galactomannan antigen assay and invasive aspergillosis in pediatric cancer patients and hematopoietic stem cell transplant recipients

Is there still a place for serum galactomannan in the diagnosis of invasive aspergillosis in children at high risk and under antifungal prophylaxis?

BACKGROUND

The performance of serum galactomannan (GM) for the diagnosis of invasive aspergillosis (IA) has been studied mainly in adults. Paediatric data are scarce and based on small and heterogeneous cohorts.

OBJECTIVE

To evaluate the performance of serum GM for the diagnosis of IA in a paediatric oncologic population at high risk of IA and to clarify the impact of antifungal prophylaxis on this test.

METHODS

We performed a retrospective study from January 2014 to December 2020 in the paediatric oncologic haematologic department of the University Hospital of Bordeaux. The diagnosis of IA was made using the recommendations of the EORTC and the MSGERC.

RESULTS

Among the 329 periods at high risk of IA in 222 patients, the prevalence of IA was 1.8% (3 proven and 3 probable IA). In the total population, the sensitivity, and the positive predictive value (PPV) were respectively 50% and 17.6%. Under antifungal prophylaxis, the sensitivity and PPV dropped, respectively, to 33.3% and 14.3%. In this group, the post-test probability of IA was 2% for a negative serum GM and only 14%.

CONCLUSION

In this large cohort of children at high risk of IA, the incidence of IA is low and the diagnostic performance of GM is poor, especially in the case of mould-active prophylaxis. Screening should be targeted rather than systematic and should be reserved for patients at highest risk for IA without mould-active prophylaxis. Combination with other tests such as Aspergillus PCR would increase the accuracy of GM in screening setting.

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.

Invasive pulmonary aspergillosis in a 4-year-old male following submersion in a manure pond

Invasive pulmonary aspergillosis (IPA) is uncommon in immunocompetent patients, but rare cases have been described after nonfatal drowning, particularly in contaminated water sources. Given subacute disease manifestations, diagnostic difficulties and the rapidly progressive nature of this organism, its mortality rate approaches 50%. Clinicians must rely on nonculture-based biomarkers and imaging to inform early diagnosis. There are currently no recommendations regarding diagnostics or empiric therapy for mold infections in near-drowning patients. We report a fatal case of IPA in a 4-year-old male following submersion in a manure pond. Early serum biomarkers and empiric voriconazole should be strongly considered in all patients after near-drowning in contaminated water sources.

Management of pulmonary aspergillosis in children: a systematic review

Invasive pulmonary aspergillosis (IPA) is a severe condition in immunocompromised children, but the optimal management is still under debate. In order to better clarify this issue, a literature search was performed through MEDLINE/PubMed database to describe current risk factors and diagnostic, therapeutic and prophylactic tools for invasive pulmonary aspergillosis (IPA) in the paediatric age. Observational studies and clinical trials regarding diagnosis, treatment and prophylaxis were considered, and results were summarised. Five clinical trials and 25 observational studies (4453 patients) were included.Haematological malignancies, previous organ transplant and other primary or acquired immunodeficiency were identified as risk factors for IPA in children.Current diagnostic criteria distinguish between "proven", "probable" and "possible" disease. Consecutive galactomannan assays have good sensitivity and specificity, especially when performed on broncho-alveolar lavage. At the same time, β-D-glucan should not be used since cut-off in children is unclear. PCR assays cannot currently be recommended for routine use.Voriconazole is the recommended first-line agent for IPA in children older than 2 years of age. Liposomal amphotericin B is preferred in younger patients or cases of intolerance to voriconazole. Its plasma concentrations should be monitored throughout the treatment. The optimal duration of therapy has yet to be determined. Posaconazole is the preferred prophylactic agent in children older than 13 years old, whereas oral voriconazole or itraconazole are the drugs of choice for those between 2-12 years. Further good-quality studies are warranted to improve clinical practice.

The role of galactomannan test results in the diagnosis of pediatric invasive aspergillosis

BACKGROUND

Invasive aspergillosis (IA) is an important cause of morbidity and mortality in immunosuppressed children. Early detection of the infection can improve prognosis in this patient population.

OBJECTIVES

To investigate the utility of Aspergillus galactomannan antigen assay (GM-EIA) as a diagnostic tool for IA in at-risk paediatric patients.

PATIENTS/METHODS

For the study, 659 GM-EIA results from 59 patients diagnosed with IA and 3368 GM-EIA results from 351 subjects without evidence for IA (controls) were reviewed retrospectively. Three cut-off values (i.e. ≥0.5, ≥1, ≥1.5) were specified to determine GM-EIA positivity.

RESULTS

The median age was 6.3 years for boys and 14.5 years for girls. There was a significant difference between the girls and boys in terms of age (p < 0.01). For proven/probable/possible IA patients, sensitivity of 67.8% and specificity of 59.8% were detected when the ≥0.5 cut-off value was used for GM-EIA-positivity. The specificity increased to 80% at the cut-off of ≥1 and to 88% at the cut-off of ≥1.5. False positivity rates were 9.14, 3, and 1.45% at the ≥0.5, ≥1 and ≥1.5 cut-offs respectively. In the proven/probable IA group, sensitivity and negative predictive values were 86.9 and 97.2% at the ≥0.5 cut-off, 85.7 and 97.9%, at the ≥1 cut-off and 84.2 and 98.1% at ≥1.5 cut-off respectively. The positive likelihood ratio was 7.57 and the odds ratio was 42.67 at ≥1.5 cut-off.

CONCLUSION

The GM-EIA may be used for both screening and diagnostic purposes in paediatric patients using a cut-off value of ≥1.5 for GM-EIA positivity.

Fungal Infections of the Gastrointestinal Tract

The thinking about fungi has evolved from unusual agents considered contaminants and colonizers to actual pathogens. Fungi are ubiquitous in nature and are found throughout in association with food, soil, mammals, and insects. Fungi have become important pathogens in animals and humans causing infections extending from superficial disease to disseminated infection. Because the gastrointestinal tract is continually exposed to fungi, it is frequently colonized and infected by numerous yeast and other fungi. It is also the origin of many disseminated fungal infections. The increased incidence of fungal infections has led to the approval and use of novel antifungals.

Assessment of Serum Galactomannan Test Results of Pediatric Patients With Hematologic Malignancies According to Consecutive Positivity and Threshold Level in Terms of Invasive Aspergillosis Diagnosis: Cross-Sectional Research in a Tertiary Care Hospital

The aim of this study was to evaluate the diagnostic utility of serum galactomannan (GM) positivity for invasive aspergillosis (IA) in children. Positive GM results between January 2015 and August 2017 were reviewed retrospectively in children with hematologic malignancies. Single and consecutive positive GM results were evaluated according to the different galactomannan index (GMI) (>0.5, >0.7, >1.0 and >1.5) values. There were 104 positive GM results of 70 patients. IA was identified in 29 patients (41.4%) (2 proven and 27 probable). For a single positive GMI of >0.5, >0.7, >1.0, and >1.5, the numbers were 104, 76, 57, and 32 and the positive predictive values (PPVs) were 39.4%, 43.2%, 47.2%, and 50.0%, respectively. The single GM positivity at different thresholds showed no difference between the IA and non-IA group (P>0.05). For 2 consecutive positive GMI values of >0.5, >0.7, >1.0, and >1.5, the numbers were 34, 20, 13, and 4, and the PPVs were 58.8%, 65.0%, 84.6%, and 100.0%, respectively. In the IA group, positivity was higher at all thresholds (P<0.05). According to our findings, consecutive GM positivity has higher PPVs independently from the cutoff value chosen. In pediatric patients with high risk, consecutive sampling should be preferred.

Diagnosis of invasive fungal disease in children: a narrative review

Introduction: Invasive fungal diseases (IFD) represent important causes of morbidity and mortality in pediatrics. Early diagnosis and treatment of IFD is associated with better outcome and this entails the need to use fast and highly sensitive and specific methods that can support clinicians in the management of IFD.Areas covered: A narrative review was performed on conventional diagnostic methods such as culture, microscopy and histopathology are still gold standard but are burdened by a lack of sensitivity and specificity; on the other hand, imaging and noninvasive antigen-based such as beta-D-glucan, galactomannan and molecular biomarkers are the most convenient nonculture methods for diagnosis and monitoring effects of therapy. Aim of the present review is to summarize what is available in these fields at end of the second decade of the third millennium and look for future perspectives.Expert opinion: Promising and useful diagnostic methods have been applied in infectious disease diagnosis in clinical practice or in designing platforms. Unfortunately, most of them are not standardized or validated in pediatric population. However, clinicians should be aware of all innovative diagnostic tools to use in combination with conventional diagnostic methods for a better management of pathology and patient.

ESCMID-ECMM guideline: diagnosis and management of invasive aspergillosis in neonates and children

SCOPE

Presenting symptoms, distributions and patterns of diseases and vulnerability to invasive aspergillosis (IA) are similar between children and adults. However, differences exist in the epidemiology and underlying conditions, the usefulness of newer diagnostic tools, the pharmacology of antifungal agents and in the evidence from interventional phase 3 clinical trials. Therefore, the European Society for Clinical Microbiology and Infectious Diseases (ESCMID) and the European Confederation of Medical Mycology (ECMM) have developed a paediatric-specific guideline for the diagnosis and management of IA in neonates and children.

METHODS

Review and discussion of the scientific literature and grading of the available quality of evidence was performed by the paediatric subgroup of the ESCMID-ECMM-European Respiratory Society (ERS) Aspergillus disease guideline working group, which was assigned the mandate for the development of neonatal- and paediatric-specific recommendations.

QUESTIONS

Questions addressed by the guideline included the epidemiology of IA in neonates and children; which paediatric patients may benefit from antifungal prophylaxis; how to diagnose IA in neonates and children; which antifungal agents are available for use in neonates and children; which antifungal agents are suitable for prophylaxis and treatment of IA in neonates and children; what is the role of therapeutic drug monitoring of azole antifungals; and which management strategies are suitable to be used in paediatric patients. This guideline provides recommendations for the diagnosis, prevention and treatment of IA in the paediatric population, including neonates. The aim of this guideline is to facilitate optimal management of neonates and children at risk for or diagnosed with IA.

Epidemiology of invasive fungal infections in immunocompromised children; an Australian national 10-year review

BACKGROUND

A thorough understanding of local and contemporary invasive fungal infection (IFI) epidemiology in immunocompromised children is required to provide a rationale for targeted prevention and treatment strategies.

METHODS

Retrospective data over 10 years from four tertiary pediatric oncology and hematopoietic stem cell transplant (HSCT) units across Australia were analyzed to report demographic, clinical, and mycological characteristics of IFI episodes, and crude IFI prevalence in select oncology/HSCT groups. Kaplan-Meier survival analyses were used to calculate 180-day overall survival.

RESULTS

A total of 337 IFI episodes occurred in 320 children, of which 149 (44.2%), 51 (15.1%), and 110 (32.6%) met a modified European Organization for Research and Treatment of Cancer (mEORTC) criteria for proven, probable, and possible IFI, respectively. There were a further 27 (8.0%) that met a "modified possible IFI" criteria. Median age at IFI diagnosis was 8.4 years. Crude mEORTC IFI prevalence in acute lymphoblastic leukemia, acute myeloid leukemia, solid tumor, and allogeneic HSCT cohorts was 10.6%, 28.2%, 4.4%, and 11.7%, respectively. Non-Aspergillus species represented 48/102 (47.1%) molds identified, and non-albicans Candida represented 66/93 (71.0%) yeasts identified. There were 56 deaths among 297 children who met mEORTC criteria, with 180-day overall survival for proven, probable, and possible IFIs of 79.7%, 76.2%, and 84.4%, respectively.

CONCLUSION

Non-Aspergillus molds and non-albicans Candida contributed substantially to pediatric IFI in our study, with high IFI prevalence in leukemia and allogeneic HSCT cohorts. Inclusion of IFIs outside of European Organization for Research and Treatment of Cancer criteria revealed an IFI burden that would go otherwise unrecognized in published reports.

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.

Determination of voriconazole and co-administered drugs in plasma of pediatric cancer patients using UPLC-MS/MS: A key step towards personalized therapeutics

Untreated invasive aspergillosis results in high mortality rate in pediatric cancer patients. Voriconazole (VORI), the first line of treatment, requires strict dose monitoring because of its narrow therapeutic index and individual variation in plasma concentration levels. Commonly co-administered drugs; either Esomeprazole (ESO) or Ondansetron (OND) have reported drug-drug interaction with VORI that should adversely alter therapeutic outcomes of the latter. Although VORI, ESO and OND are co-administered to pediatric cancer patients, the combined effect of ESO and OND on the plasma concentration levels of VORI has not been fully explored. In this study, an accurate, reliable and sensitive liquid chromatography-tandem mass spectrometry (LC-MS/MS) assay was developed and validated for simultaneous determination of VORI, ESO, and OND in ultra-low sample volumes (25 μL) of plasma of pediatric cancer patients. Based on the physicochemical properties of the studied drugs and internal standard, liquid-liquid extraction was successfully adopted with methyl t-butyl ether. Consistent and reproducible recovery of the three drugs and the internal standard were calculated using plasma and matrix matched samples (RE% > 72.97%, RSD < 8.29%). Chromatographic separation was carried out using UPLC with C18 column and a mobile phase of acetonitrile:water:methanol (70:25:5 V/V/V) at 0.3 mL/min. Mass spectrometric determination at positive electrospray ionization in the MRM mode was employed. The analysis was achieved within 4 min over a linear concentration range of 1.00-200.00 ng/mL for the three drugs. The assay validity was assessed as per the Food and Drug Administration guidelines for bioanalytical method validation, and satisfactory results were obtained. The accuracy and precision were within the acceptable limits for the three drugs in both quality control and incurred plasma samples. Matrix effect and process efficiency were investigated in neat solvent, post-extraction matrix, and plasma. Correlation of the plasma concentration levels of the three drugs revealed differences from the reported drug-drug interactions. This confirmed the need for simultaneous determination of VORI and co-administered drugs in order to achieve optimal therapeutic outcomes. To achieve this, analysis results of this study, genetic polymorphisms in CYP2C19 and clinical data will be used to establish one model incorporating all possible factors that might lead to variation in therapeutic outcomes.

Use of Galactomannan Antigen and Aspergillus DNA Real-time Polymerase Chain Reaction as Routine Methods for Invasive Aspergillosis in Immunosuppressed Children in Greece

PURPOSE

Invasive aspergillosis (IA) remains a critical issue in immunosuppressed patients. Detection of galactomannan antigen (GM) in serum samples is included as a criterion of IA by the European Organization for the Research and Treatment of Cancer/Mycoses Study Group. Nevertheless, Aspergillus DNA detection by polymerase chain reaction (PCR) has not yet been included because clinical data validation is lacking. The present study describes the simultaneous performance of GM and PCR tests as routine methods for IA diagnosis.

METHODS

During the period January 2012 to December 2017, a total of 156 white children hospitalized in a tertiary children's hospital of Athens (97 boys and 59 girls; age range, 5 months-14 years) were examined as possible cases of IA. Patients were classified into 4 groups based on their underlying diseases: hematologic malignancies (107 of 156 [68.6%]), solid tumors (16 of 156 [10.2%]), primary immunodeficiency (12 of 156 [7.7%]), and hereditary immunodeficiency (21 of 156 [13.5%]). GM detection was made with the Platelia Aspergillus Ag kit (Bio-Rad Laboratories, Hercules, California). Sera with a cut-off index ≥0.5 on at least 2 separate blood collections were considered positive. Serum detection of Aspergillus DNA was conducted with real-time PCR MycAssay Aspergillus assay (Myconostica Ltd, Cambridge, United Kingdom). PCR positivity was determined by using a threshold of 38 cycles in at least 1 serum sample. Four or more successive samples per patient were tested.

FINDINGS

Overall, 28 of 156 patients (53 of 744 serum samples) were found positive. Eleven patients were positive using both methods (24 samples). Four children were positive only by PCR (6 samples), whereas 13 (23 samples) were positive only with GM in consecutive samples. Agreement of both methods, GM(+)/PCR(+) or GM(-)/PCR(-), was found in 139 patients (90% of total patients) and 715 samples (96.1% of total samples). The agreement of both methods was found: (1) 85% in patients with hematologic malignancies; (2) 100% in patients with solid tumors; (3) 97.5% in patients with primary immunodeficiency; and (4) 98.8% in patients with hereditary immunodeficiency. Overall disagreement was observed in 17 patients, in which the positive result in any of the 2 methods was estimated as true positive in conjunction with radiologic and other clinical findings.

IMPLICATIONS

The combination of GM and PCR, provided high diagnostic accuracy in consecutive samples (twice a week). Clinical, radiologic, and other laboratory findings should be taken into consideration in the evaluation of GM and PCR.

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

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

Serum galactomannan for diagnosing invasive aspergillosis in pediatric patients: A meta-analysis

BACKGROUND

The serum galactomannan (GM) assay is used to diagnose invasive aspergillosis (IA). We conducted a systematic review and analysis to estimate the overall accuracy of the serum GM test for diagnosing pediatric IA.

METHOD

A systematic literature review was conducted of all relevant studies published in PubMed and EMbase databases up to March 10, 2017. We selected and assessed articles that reported diagnostic data related to serum GM for diagnosis of pediatric IA. Pooled diagnostic odds ratios (DORs) and summary receiver operating characteristics (SROCs) were constructed with a cutoff value of 0.5. Additionally, pooled sensitivity (SEN), specificity (SPE), and positive and negative likelihood ratios (PLR and NLR, respectively) were estimated for summarizing overall test performance.

RESULTS

Seventeen studies were included in this systematic review. The total number of patients (age range 0-21 years old) was 1768, with 178 that had proven or probable IA. The pooled serum GM assay results, with a cutoff value of 0.5 for proven or probable IA, were DOR: 41.16 (95% confidence interval (CI) 21.48-78.86), SEN: 0.85 (95% CI 0.72-0.93), SPE: 0.88 (95% CI 0.80-0.93), PLR: 6.92 (95% CI 4.40-10.88), and NLR: 0.17 (95% CI 0.09-0.32). The SROC was 0.93.

CONCLUSION

Serum GM can be used to assist in diagnosis of proven or probable pediatric IA. However, serum GM test results should be interpreted in combination with clinical findings in pediatric IA cases, as the test results are not always sensitive or specific enough for pediatric IA.

Voriconazole plus caspofungin for treatment of invasive fungal infection in children with acute leukemia

Background

Invasive fungal infections (IFIs) are a life-threatening problem in immunocompromised patients. Despite timely diagnosis and appropriate antifungal therapy, clinical outcomes of IFIs remain unsatisfactory, necessitating treatment with a combination of antifungal agents. Therefore, childhood leukemic patients treated with voriconazole plus caspofungin were evaluated for the safety and efficacy of the combination antifungal therapy to treat IFIs.

Methods

In this retrospective study, medical records were retrieved for patients admitted to the Pediatric Department of Yeungnam University Hospital, Daegu, South Korea, between April 2009 and May 2013. Medical records of 22 patients were analyzed.

Results

Of the 22 patients studied, nine (41%) had been diagnosed with probable IFI, and 13 (59%) with possible IFI. All patients, except one, were already receiving antifungal monotherapy for the treatment of neutropenic fever. After a diagnosis of IFI was confirmed, antifungal monotherapy was replaced with combination therapy. The study's overall response rate was 90.9%, with complete responses in 86.3% of the patients. Two patients experienced a side effect of a small increase in liver enzyme levels.

Conclusion

Voriconazole plus caspofungin combination therapy is an effective and safe treatment for serious IFI in pediatric patients with acute leukemia.

Role of Molecular Biomarkers in the Diagnosis of Invasive Fungal Diseases in Children

Invasive fungal diseases are important clinical problems that are often complicated by severe illness and therefore the inability to use invasive measures to definitively diagnose the disease. Tests for a range of fungal biomarkers that do not require an invasive sample-collection procedure have been incorporated into adult clinical practice, but pediatric data and pediatric-specific recommendations for some of these diagnostic tools are lacking. In this review, we summarize the published literature and contemporary strategies for using the biomarkers galactomannan, (1→3)-β-d-glucan, Candida mannan antigen and anti-mannan antibody, and fungal polymerase chain reaction for diagnosing invasive fungal disease in children. Data on biomarker use in neonates and children with cancer, history of hematopoietic stem cell transplant, or primary immunodeficiency are included. Fungal biomarker tests performed on blood, other body fluids, or tissue specimens represent promising adjuncts to the diagnostic armamentarium in populations with a high prevalence of invasive fungal disease, but substantial gaps exist in the correct use and interpretation of these diagnostic tools in pediatric patients.

Progress in the Diagnosis of Invasive Fungal Disease in Children

PURPOSE OF REVIEW

This review summarizes the fungal diagnostic measures currently available for use in paediatric patients at high risk for developing invasive fungal disease (IFD) and those suspected of having an IFD. The clinical utility of each test is described based on reported performances of individual tests in specific paediatric populations.

RECENT FINDINGS

Available studies in the paediatric population are scarce and are characterized by a huge heterogeneity in underlying diseases (e.g. different risk for IFD), different study objectives and management strategies (screening versus diagnostic) used.

SUMMARY

A final valuation of paediatric studies on fungal diagnostic tools is limited. While the galactomannan and fungal PCR assays are useful to exclude the presence of IFD, it is unclear if mannan, mannan antibodies and β-D-glucan are of benefit due to a lack of studies or validation of the cut-off, respectively. Well-designed multicentre paediatric studies are urgently needed to improve the outcome of IFD.

Guideline for the Management of Fever and Neutropenia in Children With Cancer and Hematopoietic Stem-Cell Transplantation Recipients: 2017 Update

Purpose To update a clinical practice guideline (CPG) for the empirical management of fever and neutropenia (FN) in children with cancer and hematopoietic stem-cell transplantation recipients. Methods The International Pediatric Fever and Neutropenia Guideline Panel is a multidisciplinary and multinational group of experts in pediatric oncology and infectious diseases that includes a patient advocate. For questions of risk stratification and evaluation, we updated systematic reviews of observational studies. For questions of therapy, we conducted a systematic review of randomized trials of any intervention applied for the empirical management of pediatric FN. The Grading of Recommendation Assessment, Development and Evaluation approach was used to make strong or weak recommendations and to classify levels of evidence as high, moderate, low, or very low. Results Recommendations related to initial presentation, ongoing management, and empirical antifungal therapy of pediatric FN were reviewed; the most substantial changes were related to empirical antifungal therapy. Key differences from our 2012 FN CPG included the listing of a fourth-generation cephalosporin for empirical therapy in high-risk FN, refinement of risk stratification to define patients with high-risk invasive fungal disease (IFD), changes in recommended biomarkers and radiologic investigations for the evaluation of IFD in prolonged FN, and a weak recommendation to withhold empirical antifungal therapy in IFD low-risk patients with prolonged FN. Conclusion Changes to the updated FN CPG recommendations will likely influence the care of pediatric patients with cancer and those undergoing hematopoietic stem-cell transplantation. Future work should focus on closing research gaps and on identifying ways to facilitate implementation and adaptation.

The Changing Epidemiology of Invasive Fungal Infections

Invasive fungal infections (IFI) are an emerging problem worldwide with invasive candidiasis and candidemia responsible for the majority of cases. This is predominantly driven by the widespread adoption of aggressive immunosuppressive therapy among certain patient populations (e.g., chemotherapy, transplants) and the increasing use of invasive devices such as central venous catheters (CVCs). The use of new immune modifying drugs has also opened up an entirely new spectrum of patients at risk of IFIs. While the epidemiology of candida infections has changed in the last decade, with a gradual shift from C. albicans to non-albicans candida (NAC) strains which may be less susceptible to azoles, these changes vary between hospitals and regions depending on the type of population risk factors and antifungal use. In certain parts of the world, the incidence of IFI is strongly linked to the prevalence of other disease conditions and the ecological niche for the organism; for instance cryptococcal and pneumocystis infections are particularly common in areas with a high prevalence of HIV disease. Poorly controlled diabetes is a major risk factor for invasive mould infections. Environmental factors and trauma also play a unique role in the epidemiology of mould infections, with well-described hospital outbreaks linked to the use of contaminated instruments and devices. Blastomycosis is associated with occupational exposure (e.g., forest rangers) and recreational activities (e.g., camping and fishing).The true burden of IFI is probably an underestimate because of the absence of reliable diagnostics and lack of universal application. For example, the sensitivity of most blood culture systems for detecting candida is typically 50 %. The advent of new technology including molecular techniques such as 18S ribosomal RNA PCR and genome sequencing is leading to an improved understanding of the epidemiology of the less common mould and dimorphic fungal infections. Molecular techniques are also providing a platform for improved diagnosis and management of IFI.Many factors affect mortality in IFI, not least the underlying medical condition, choice of therapy, and the ability to achieve early source control. For instance, mortality due to pneumocystis pneumonia in HIV-seronegative individuals is now higher than in seropositive patients. Of significant concern is the progressive increase in resistance to azoles and echinocandins among candida isolates, which appears to worsen the already significant mortality associated with invasive candidiasis. Mortality with mould infections approaches 50 % in most studies and varies depending on the site, underlying disease and the use of antifungal agents such as echinocandins and voriconazole. Nevertheless, mortality for most IFIs has generally fallen with advances in medical technology, improved care of CVCs, improved diagnostics, and more effective preemptive therapy and prophylaxis.

Galactomannan, β-D-Glucan, and Polymerase Chain Reaction-Based Assays for the Diagnosis of Invasive Fungal Disease in Pediatric Cancer and Hematopoietic Stem Cell Transplantation: A Systematic Review and Meta-Analysis

We systematically reviewed and analyzed the available data for galactomannan (GM), β-D-glucan (BG), and polymerase chain reaction (PCR)-based assays to detect invasive fungal disease (IFD) in patients with pediatric cancer or undergoing hematopoietic stem cell transplantation when used as screening tools during immunosuppression or as diagnostic tests in patients presenting with symptoms such as fever during neutropenia (FN). Of 1532 studies screened, 25 studies reported on GM (n = 19), BG (n = 3), and PCR (n = 11). All fungal biomarkers demonstrated highly variable sensitivity, specificity, and positive predictive values, and these were generally poor in both clinical settings. GM negative predictive values were high, ranging from 85% to 100% for screening and 70% to 100% in the diagnostic setting, but failure to identify non-Aspergillus molds limits its usefulness. Future work could focus on the usefulness of combinations of fungal biomarkers in pediatric cancer and HSCT.

Diagnosis of invasive fungal diseases in pediatric patients

INTRODUCTION

The optimal management of invasive fungal infections (IFIs) in children requires prompt and precise diagnosis that enables timely implementation of appropriate antifungal therapy and decreased use of unnecessary toxic antifungals. Areas covered: Traditional approaches such as culture, microscopy and histopathology remain the gold standard but are often not sufficiently sensitive and specific. These limitations have led to the development of alternative non-invasive diagnostic methods that in most cases detect fungal components, such as antigens or nucleic acids. To date, galactomannan and 1,3 β-D-glucan assays are the most efficient non-culture methods for diagnosis and monitoring of antifungal therapy. New technologies from nano-sciences are applied, like T2Candida assay. However, these are not standardized or validated in children. Herein, we focus on IFI diagnosis emphasizing current perspectives, interpretation difficulties, and need for further evaluation in pediatrics. Expert commentary: The new diagnostic tools may enhance diagnostic capacity in combination with traditional methods.

Practice Guidelines for the Diagnosis and Management of Aspergillosis: 2016 Update by the Infectious Diseases Society of America

It is important to realize that guidelines cannot always account for individual variation among patients. They are not intended to supplant physician judgment with respect to particular patients or special clinical situations. IDSA considers adherence to these guidelines to be voluntary, with the ultimate determination regarding their application to be made by the physician in the light of each patient's individual circumstances.

Pediatric Invasive Aspergillosis

Invasive aspergillosis (IA) is a disease of increasing importance in pediatrics due to growth of the immunocompromised populations at risk and improvements in long-term survival for many of these groups. While general principles of diagnosis and therapy apply similarly across the age spectrum, there are unique considerations for clinicians who care for children and adolescents with IA. This review will highlight important differences in the epidemiology, clinical manifestations, diagnosis, and therapy of pediatric IA.

Clinical Features and Prognosis of Invasive Pulmonary Aspergillosis in Korean Children with Hematologic/Oncologic Diseases

Invasive pulmonary aspergillosis (IPA) is the most frequent form of invasive fungal diseases in immunocompromised patients. However, there are only a few studies on IPA in immunocompromised children in Korea. This study was designed to characterize IPA in Korean children with hematologic/oncologic diseases. Medical records of children with hematologic/oncologic diseases receiving antifungal therapy were reviewed. The enrolled children were divided into the IPA group (proven and probable IPA) and non-IPA group, and the clinical characteristics and prognosis were compared between the two groups. During the study period, 265 courses of antifungal therapy were administered to 166 children. Among them, two (0.8%) episodes of proven IPA, 35 (13.2%) of probable IPA, and 52 (19.6%) of possible IPA were diagnosed. More children in the IPA group suffered from neutropenia lasting for more than two weeks (51.4% vs. 21.9%, P<0.001) and showed halo signs on the chest computed tomography (78.4% vs. 40.7%, P<0.001) than in the non-IPA group. No other clinical factors showed significant differences between the two groups. Amphotericin B deoxycholate was administered as a first line antifungal agent in 33 (89.2%) IPA group episodes, and eventually voriconazole was administered in 27 (73.0%) episodes. Ten (27.0%) children in the IPA group died within 12 weeks of antifungal therapy. In conclusion, early use of chest computed tomography to identify halo signs in immunocompromised children who are expected to have prolonged neutropenia can be helpful for early diagnosis of IPA and improving prognosis of children with IPA.

Serum galactomannan index for early prediction of mortality in immunocompromised children with invasive pulmonary aspergillosis

Background

Invasive pulmonary aspergillosis (IPA) is the most common invasive fungal disease in immunocompromised patients, and it has a 30 % mortality rate despite appropriate antifungal therapy. This retrospective study was performed to determine risk factors for mortality in immunocompromised children with IPA.

Methods

Medical records of 45 probable/proven IPA cases diagnosed in children with hematologic/oncologic diseases were reviewed. Selected cases were divided into the survival (n = 30) and fatality (n = 15) groups based on survival at 12 weeks after antifungal therapy. Clinical characteristics and serum galactomannan indices (GMIs) were compared between the two groups.

Results

Significantly more children in the fatality group were male (p = 0.044), not in complete remission of the underlying malignancies (p = 0.016), and had received re-induction/salvage or palliative chemotherapy (p = 0.035) than those in the survival group. However, none of these factors was significantly associated with mortality in a multivariate analysis. Serum GMIs were higher in the fatality group than in the survival group during the entire period of antifungal therapy, and serum GMI at 1 week after antifungal therapy was most significantly associated with mortality. A serum GMI > 1.50 at 1 week after antifungal therapy exhibited a sensitivity and specificity of 61.5 % and 89.3 %, respectively, in predicting mortality within 12 weeks after antifungal therapy.

Conclusions

Higher serum GMI in the early phase of antifungal therapy was associated with mortality in immunocompromised children with IPA. These children should receive more intensive care for IPA than others.

Assessment Techniques to Detect Aspergillus fumigatus in Different Samples of Immunosuppressed Male Western Albino Rats

Background:

There are several conventional, immunological and molecular techniques to diagnose the fungi that cause aspergillosis in biological samples; these methods have some advantages and disadvantages.

Objectives:

The current study aimed to evaluate different methods used in identification and diagnosis of fungi causing aspergillosis.

Materials and Methods:

Male Western Albino rats were provided by Animal Care Unit at Faculty of Pharmacy, King Saud University. After adaptation for a reasonable period, rat's immunity was debilitated by injection of cyclophosphamide (i.p.); the infection was induced by injecting (i.v.) the prepared suspension of Aspergillus fumigatus spores. Blood samples, lung tissue, lung fluid smears and nasal fluid smears were obtained during the periods before and after injection. Isolation of fungus was carried out by synthetic media; and macro- and micro-characteristics were studied to identify the fungus. Enzyme-linked immunesorbent (ELISA) and LightCycler-based PCR was employed to check the existence of the fungus in blood samples.

Results:

The results indicated that all methods were unable to diagnose the A. fumigatus on the following day of infection except ELISA method; however, culturing methods varied according to the type of vital samples where lung tissue and lung fluid smears were the best. Moreover, more than half of the samples used in the culturing techniques had negative results. The highest rate of the cases diagnosed by ELISA and polymerase chain reaction (PCR) was recorded during the second week following the infection, and then it declined gradually till the end of the experiment. The molecular methods showed high efficiency followed by ELISA.

Conclusions:

It could be concluded that the best methods to identify A. fumigatus were molecular methods; however, the early diagnosis requires the enzymatic-immunological methods (ELISA). The current study recommends the integration among all possible techniques whenever the facilities are available. But when only microbiological methods are used, samples should be collected from different organs of the infected hosts.

Serum galactomannan screening for diagnosis of invasive pulmonary aspergillosis in children after stem cell transplantation or with high-risk leukemia

Both transplanted and leukemia patients are at high risk (HR) for invasive pulmonary aspergillosis (IPA). Methods for rapid diagnosis are crucial. Our objective was to investigate the impact of serial serum galactomannan assay (GMA) screening on IPA diagnosis in children. Between January 2010 and December 2011, all children following stem cell transplantation (SCT) or with HR leukemia were prospectively included. Serum samples for GMA were taken once-twice weekly. Results >.5 were considered positive. Patients suspected of having IPA were stratified as possible, probable, and definite. Forty-six children (median age, 8 years) were included, 38 after SCT (32 allogeneic), 8 with HR leukemia. A total of 510 samples were taken; screening period was 1-6 months for 34 patients. GMA was negative in 28 patients, all but one without suspicion of IPA. Eighteen patients had positive GMA: while four (22%) were upgraded to probable IPA, fourteen (78%) were considered as false positives (FP), some associated with piperacillin-tazobactam treatment. GMA sensitivity and specificity were 0.8 and 0.66, respectively; positive- and negative-predictive values (PPV, NPV) were 0.22 and 0.96, respectively. GMA may have a role in evaluating HR children for IPA. Both NPV and FP rates are high. The cost benefit of early detection versus over-diagnosis should be further studied.

Invasive fungal infections in children with hematologic and malignant diseases

BACKGROUND

To evaluate the clinical feature and outcome of invasive fungal infections (IFI) in children with hematologic and malign diseases.

PATIENTS AND METHODS

The medical records of children with hematologic and malignant diseases, who were hospitalized at our hospital between January 2010 and December 2011, were reviewed. Proven, probable, and possible IFIs were diagnosed according to the revised definitions of the European Organization for Research and Treatment of Cancer/Mycosis Study Group. The demographic, clinical, and laboratory characteristics of the patients who met the study criteria were evaluated.

RESULTS

IFI was diagnosed in 67 (7.2%) febrile episodes of 56 patients, of which 10 (1.2%) were proven, 20 (2%) probable, and 37 (4%) possible IFI. Blood culture of 10 cases with proven IFI yielded yeast and the most common isolated agent was Candida parapsilosis. Seventy percent of cases with fungemia had central venous catheter (CVC). Twenty cases with probable IFI had invasive mold infection. The cases with mold infection had higher median C-reactive protein values, lower neutrophil counts, and longer duration of neutropenia compared with the cases with yeast infection. A total of 14 patients (20.9%) died. Presence of CVC, bone marrow transplantation, total parenteral nutrition, prolonged fever, and proven/probable IFI were detected more often in patients who died, compared with patients who survived.

CONCLUSIONS

IFIs are important causes of death in children with hematologic and malignant diseases. Mold infections are seen more frequently in cases with prolonged and profound neutropenia, and invasive yeast infections, especially with non-albicans Candida species, in cases with CVC. Early and effective treatment considering these findings will help to decrease the mortality.

Computed tomography guided percutaneous lung biopsies and suspected fungal infections in pediatric cancer patients

BACKGROUND

The spectrum of potential fungal pathogens known to cause invasive pulmonary infections has grown as a result of intensified immunosuppressive therapy and the emergence of antifungal resistance.

PROCEDURE

In a retrospective single center study, we investigated computed tomography guided percutaneous lung biopsies in 16 childhood patients with suspected fungal infections. Microbiological analysis consisted of microscopic examination, culture, and a broad-range fungal polymerase chain reaction for detection of either Aspergillus or Mucorales species.

RESULTS

In 14 patients (88%), invasive fungal infection with Aspergillus species including A. terreus, Mucormycetes, and Saccharomyces cerevisiae being the main pathogens was confirmed, including patients with a double infection (19%). In two cases, the most likely diagnosis of primary bronchiolitis obliterans organizing pneumonia was established based on the results of typical histopathologic features, negative culture results, and symptoms resolved after treatment with high-dose cortisone. Diagnosis of invasive fungal pneumonia led to an immediate interruption of antineoplastic treatment in 100%, reduction of antibiotic drugs in 76%, and change of empirical to targeted antifungal therapy in 63%. The safety of lung biopsy was guaranteed by lack of any complications, such as bleeding or pneumothorax.

CONCLUSIONS

The increased detection of rare fungal infections by computed tomography guided biopsy supports the need for a rapid and precise diagnosis, as most of the fungal pathogens are at least partially resistant to available antifungal therapy and proper treatment is essential for best practice in patient management.

Nonmolecular methods for the diagnosis of respiratory fungal infections

Diagnosis of invasive fungal pneumonias by conventional culture methods is difficult to assess and often delayed. Nonmolecular fungal markers have emerged as an important adjunctive tool to support their diagnosis in combination with other clinical, radiologic, and microbiological criteria of invasive fungal diseases. Concerns about the sensitivity and specificity of some tests in different patient populations should lead to warnings about their widespread use. None can identify the emerging and particularly deadly fungal pathogens responsible for mucormycosis. The role of nonmolecular fungal markers should be better defined in combination with other microbiological and radiologic tools in preemptive antifungal strategies.