Improved diagnostic markers for invasive pulmonary aspergillosis in COPD patients

Background

The prevalence of invasive pulmonary aspergillosis (IPA) among patients with chronic obstructive pulmonary disease (COPD) is steadily increasing, leading to high mortality. Although early diagnosis can significantly reduce mortality, the efficacy of current diagnostic methods is limited. Consequently, there is a need for novel approaches for early IPA detection.

Methods

This retrospective study involved 383 hospitalized COPD patients with GOLD stages III and IV. The IPA group (67 patients) and non-IPA group (316 patients) were identified at the First Affiliated Hospital of Guangzhou Medical University between January 2016 and February 2022. We analyzed common serological indicators in our hospital to identify predictive indicators for the early diagnosis of IPA in COPD patients.

Results

The sensitivity and specificity of C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), procalcitonin (PCT), lactate dehydrogenase (LDH), and ceruloplasmin (CER) for diagnosing IPA in COPD patients were as follows: CRP (91.2%, 57.7%), ESR (77.5%, 73.0%), PCT (60.5%, 71.4%), LDH (50.0%, 88.8%), and CER (60.7%, 74.3%). Combinations of biomarkers, such as CRP-ESR, CRP-LDH, ESR-LDH, ESR-CER, and LDH-CER, showed promising diagnostic potential, with larger area under the curve (AUC) values for IPA diagnosis in COPD patients. However, no statistically significant difference was observed between the diagnostic efficacy of single biomarkers and combined biomarkers. Notably, compared to those in the unassisted ventilation group, the patients in the assisted ventilation group (including noninvasive ventilation and tracheal intubation/incision-assisted ventilation group) exhibited significantly greater PCT and LDH levels, while the CER significantly decreased (p=0.021). There were no significant differences in biomarker levels between the ICU group and the non-ICU group. CRP (p<0.01), ESR (p=0.028), PCT (p<0.01), and CER (p<0.01) were positively correlated with hospitalization duration, whereas LDH was not correlated with hospitalization duration.

Conclusion

Our study highlights the diagnostic potential of CRP, ESR, PCT, LDH, and CER for IPA in COPD patients. CRP and LDH can also initially predict the need for assisted ventilation, while CRP can initially estimate the length of hospitalization. This study represents the first report of the potential of CER for diagnosing IPA, suggesting its significance for further research.

Osteomyelitis of Jaw Bone due to Aspergillosis in Post-COVID-19 Patients: An Observational Study

Background

In the second wave of COVID-19 pandemic, there has been an increase in number of cases with Post-COVID-19 fungal osteomyelitis of jaws. Aspergillosis was found to be one of the causes of osteomyelitis of jaw bones in these patients.

Aim

To evaluate the incidence and pattern of osteomyelitis of jaw due to aspergillosis in post-COVID-19 patients and to discuss the management protocol of the same.

Method

Data were obtained at our institution from the period of January 2021 to June 2021. Patients of all age groups with Post-COVID-19 osteomyelitis of jaw due to aspergillosis and those with combined aspergillosis and mucormycosis infection were included. Patients having rhino-orbito-cerebral fungal infection were excluded.

Results

A total of 47 patients reported to our center. Demographically the average age of the patients was 49.11 years with 72% being males. All 47 patients (N = 100%) had received steroids. 21 of them (N = 44.7%) had diabetes mellitus and 14 (N = 29.8%) patients had other comorbidities. Out of 47 patients, 42 (N = 89.7%) patients were diagnosed with aspergillosis and the remaining 5 (N = 10.3%) cases had a mixed fungal infection of mucormycosis and aspergillosis. On fungal culture Aspergillus flavus was the most common species detected followed by Aspergillus niger and Aspergillus fumigatus. All patients were treated with oral Voriconazole and local surgical debridement. Prompt laboratory testing such as a timely KOH mount, galactomannan test, beta-D-glucan test, histopathology of tissue specimens could help to give an early and definitive diagnosis. The mortality rate we encountered in this study was nil.

Conclusions

Early and definitive diagnosis and immediate initiation of antifungal drug therapy and surgical intervention will significantly reduce the rate of morbidity and mortality.

Comparison of the Performance of Two Galactomannan Detection Tests: Platelia Aspergillus Ag and Aspergillus Galactomannan Ag Virclia Monotest

The use of nonculture-based biomarkers such as the determination of galactomannan is sought for the diagnosis of invasive aspergillosis. To investigate the comparative yield of two tests for the detection of galactomannan in patients with or without proven or probable invasive aspergillosis. Overall, 327 samples (327 patients) were analyzed in a retrospective/prospective study performed in 3 hospitals in Madrid, comparing the determination results in serum or bronchoalveolar lavage of two techniques for galactomannan detection, namely, Platelia Aspergillus Ag (Bio-Rad) and Aspergillus galactomannan Ag Virclia Monotest (Vircell S.L.), following the manufacturer's instructions. Both techniques can automate the process, but the second technique has the advantage of individual processing and assembly of each sample without the need for the additional expense of single-dose strips in controls. In total, 288 of the 327 tests performed showed concordant results between both techniques. The agreement between both methods was к = 0.722, and the correlation between indices was ρ = 0.718. Only 39 samples showed discordant results. In those 39 cases, there were 15 patients with proven or probable invasive aspergillosis criteria. For the samples with clinical criteria as a reference, the areas under the curve of the receiver operating characteristic (ROC) curve were 0.962 for Platelia and 0.968 for VirClia. The VirClia test has been proven to be an alternative for diagnosis due to its friendlier automated format than that of the usual Platelia routine test. The VirClia test also allows individual action and, therefore, a more immediate clinical response. IMPORTANCE Invasive mycoses are increasingly present in immunosuppressed or hospitalized patients with serious illnesses, leading to high rates of morbidity and mortality. Invasive aspergillosis is an infection caused, in a percentage greater than 50%, by the genus Aspergillus. It is vitally important to make an early diagnosis that leads to the application of antifungals in the initial stage of the infection. Therefore, tools are required to help with the early diagnosis of the infection. This comparative study of two enzyme immunoassays is based on the detection of galactomannan antigen in serum and bronchoalveolar lavage samples. A new design based on chemiluminescence and presented in an automated single-dose format is compared to a conventional ELISA technique marketed for years. The results obtained from the prospective and retrospective study indicate a high correlation and degree of agreement between both techniques, as well as in their diagnostic performance.

Development and evaluation of a novel fast broad-range PCR and sequencing assay (FBR-PCR/S) using dual priming oligonucleotides targeting the ITS/LSU gene regions for rapid diagnosis of invasive fungal diseases: multi-year experience in a large Canadian healthcare zone

Background

This study evaluated the performance of a novel fast broad range PCR and sequencing (FBR-PCR/S) assay for the improved diagnosis of invasive fungal disease (IFD) in high-risk patients in a large Canadian healthcare region.

Methods

A total of 114 clinical specimens (CS) including bronchoalveolar lavages (BALs) were prospectively tested from 107 patients over a 2-year period. Contrived BALs (n = 33) inoculated with known fungi pathogens were also tested to increase diversity. Patient characteristics, fungal stain and culture results were collected from the laboratory information system. Dual-priming oligonucleotide (DPO) primers targeted to the internal transcribed spacer (ITS) (~ 350 bp) and large subunit (LSU) (~ 550 bp) gene regions were used to perform FBR-PCR/S assays on extracted BALs/CS. The performance of the molecular test was evaluated against standard microbiological methods and clinical review for the presence of IFD.

Results

The 107 patients were predominantly male (67, 62.6%) with a mean age of 59 years (range = 0–85 years): 74 (69.2%) patients had at least one underlying comorbidity: 19 (34.5%) had confirmed and 12 (21.8%) had probable IFD. Culture recovered 66 fungal isolates from 55 BALs/CS with Candida spp. and Aspergillus spp. being most common. For BALs, the molecular assay vs. standard methods had sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV), and efficiency of 88.5% vs.100%, 100% vs. 61.1%, 100% vs. 88.5%, 61.1% vs. 100%, and 90.2% for both. For other CS, the molecular assay had similar performance to standard methods with sensitivity, specificity, PPV, NPV and efficiency of 66.7%, 87.0%, 66.7%, 87.0% and 81.3% for both methods. Both methods also performed similarly, regardless of whether CS stain/microscopy showed yeast/fungal elements. FBR-PCR/S assays results were reported in ~ 8 h compared to fungal cultures that took between 4 and 6 weeks.

Conclusions

Rapid molecular testing compared to standard methods have equivalent diagnostic efficiency but improves clinical utility by reporting a rapid species-level identification the same dayshift (~ 8 h).

Changing Epidemiology of Invasive Fungal Disease in Allogeneic Hematopoietic Stem Cell Transplantation

Invasive fungal disease (IFD) is a common cause of morbidity and mortality in patients with hematologic malignancies, especially among those undergoing allogeneic hematopoietic stem cell transplantation (HSCT). The epidemiology of IFD in HSCT patients has been evolving over the last decades, mainly in relation to changes in HSCT therapies such as antifungal prophylaxis. A progressive decrease in Candida albicans infection has been documented, alongside a progressive increase in infections caused by non-albicans Candida species, filamentous fungi, and/or multidrug-resistant fungi. Currently, the most frequent IFD is invasive aspergillosis. In some parts of the world, especially in north Central Europe, a high percentage of Aspergillus fumigatus isolates are azole-resistant. New diagnostic techniques have documented the existence of cryptic Aspergillus species with specific characteristics. An increase in mucormycosis and fusariosis diagnoses, as well as diagnoses of other rare fungi, have also been described. IFD epidemiology is likely to continue changing further due to both an increased use of mold-active antifungals and a lengthened survival of patients with HSCT that may result in hosts with weaker immune systems. Improvements in microbiology laboratories and the widespread use of molecular diagnostic tools will facilitate more precise descriptions of current IFD epidemiology. Additionally, rising resistance to antifungal drugs poses a major threat. In this scenario, knowledge of current epidemiology and accurate IFD diagnoses are mandatory in order to establish correct prophylaxis guidelines and appropriate early treatments.

Diagnostic value of serum human Galactomannan aspergillus antigen and 1,3-beta-D-glucan in immunocompromised patient suspected fungal infection

BACKGROUND

The prevalence of fungal infection (FI) in developing countries is high, but the diagnosis of FI is still challenging to determine, so it is needed evaluation of biomarkers other than microbiological culture, because the culture has low sensitivity, high cost, not available in every laboratory and needs a long time. The detection of human galactomannan Aspergillus antigen (GAL) and 1,3-beta-D-glucan (BDG) on the fungal cell wall could be the promising biomarkers for fungal infection. Neutropenia, lymphopenia and CD4T cells in the immunocompromised patients are essential factors, but these cell associations with BDG and GAL levels have not been evaluated yet. The study aimed to evaluate GAL and BDG for detecting fungal infection and their association with total leucocyte count, neutrophil, monocyte, lymphocyte and CD4T cells.

METHOD

A cross-sectional study was conducted among 86 patient with suspected FI. Fungal infection established using EORTC/MSG criteria. Serology test performed using ELISA. Leucocyte cells were measured using a haematology autoanalyser, and CD4T cells were analysed using BD FACSPresto. Statistical analysis obtained using Spearman's correlation coefficient, ROC curve analysis and 2 × 2 contingency table.

RESULTS

Serum Galactomannan and BDG had a significant correlation with CD4T cells and total lymphocyte count (p < 0.05). The cut-off OD GAL >0.3 had sensitivity 54.6%, specificity 87.5% and AUC 0.71; meanwhile, the BDG cut-off >115.78 pg/ mL had sensitivity 71.2%, specificity 52.4% and AUC 0.63 for detecting fungal infection.

CONCLUSIONS

The immunocompromised patients can undergo GAL for determining the diagnose of FI. The lower the CD4T cells and total lymphocyte count, the higher the GAL and BDG serum levels.

Detection of invasive pulmonary aspergillosis in mice using lung perfusion single-photon emission computed tomography with [99mTc]MAA

There is an urgent need for development of better diagnostic strategies to improve outcomes in patients with invasive pulmonary aspergillosis (IPA). We hypothesized that lung perfusion single-photon emission computed tomography (SPECT) may be more sensitive and specific than computed tomography (CT) of the chest for detection of IPA because it is an angioinvasive pulmonary infection with characteristics that are different from those of bacterial pneumonia. We used SPECT with injection of technetium-99m-labeled macroaggregated albumin ([99mTc]MAA) to measure pulmonary perfusion in noninfected mice, mice with IPA, and mice with bacterial pneumonia. Histopathologic analysis was performed to evaluate the correlation between the perfusion defect and mould invasion. We also attempted to quantitatively evaluate the SPECT images to identify differences in decreased perfusion levels in affected areas in the mouse lung. Histopathologic analysis in the IPA mouse model showed a clear match between areas with a perfusion defect and the presence of mold, indicating that the location of the perfusion defect on a SPECT image reflects angioinvasion of the mould in the lungs. Some of these perfusion defects could be seen before appearance of the infiltrate of CT images. Quantitative analysis confirmed that perfusion in the affected areas was significantly decreased in the IPA model but not in the bacterial pneumonia model (P < .0001). This imaging method may be preferable to the alternative methods presently used to identify the presence of mold in a patient's lungs.

Defining standards of CARE for invasive fungal diseases in adult haematology patients: antifungal prophylaxis versus treatment

Despite the availability of four different classes of antifungal agents, invasive fungal infections, in particular mould diseases, continue to have a high crude mortality rate in adult haematology patients, especially when diagnosed late. Early diagnosis, resulting in prompt and adequate antifungal intervention, is of great importance when trying to improve the overall outcome of these infections, but depends on the availability of rapid and sensitive diagnostic tools. The medical community has developed and continues to evaluate a continuum of antifungal strategies (starting with prophylaxis followed by empirical therapy and more recently a diagnostic-driven or pre-emptive approach) to better tackle these life-threatening diseases. While the empirical approach seems to have lost some of its popularity, the jury is still out about the pros and cons of universal antifungal prophylaxis in at-risk adult haematology patients compared with an approach that uses radiological and mycological diagnostic methods with good to excellent negative predictive values (also erroneously called pre-emptive), trying to exclude the presence of an invasive fungal disease. Whilst awaiting the results of comparative clinical studies, believers and non-believers around the globe continue to argue about the advantages and shortcomings of both strategies. The debate presented here provides a rationale for both prophylaxis for 'high-risk' haematology patients as well as for a more targeted approach based on the appropriate use of mycological, radiological, immunological (and genetic) methods for the diagnosis of invasive fungal diseases.

Disseminated cerebral aspergillosis complicated by thrombotic microangiopathy

Invasive aspergillosis (IA) is a serious condition that can affect almost any organ. Cerebral aspergillosis itself is rapidly fatal without treatment. We report a case of disseminated cerebral IA in a patient exposed to cyclophosphamide, rituximab and prednisone. This case is unique because: 1) disseminated IA has not been described in anti-glomerular basement membrane glomerulonephritis; 2) IA led to thrombotic microangiopathy with normal ADAMTS13 and 3) voriconazole toxicity necessitated use of isavuconazole for IA treatment.

Extended Dosing Regimens for Fungal Prophylaxis

Invasive fungal diseases carry high morbidity and mortality in patients undergoing chemotherapy for hematological malignancies or allogeneic hematopoietic stem cell transplantation. In order to prevent these life-threatening infections, antifungal chemoprophylaxis plays an important role in daily clinical practice. Broad-spectrum antifungal triazoles are widely used but exhibit disadvantages such as relevant drug-drug interactions. Therefore, amphotericin B products or echinocandins can be an alternative in selected patient populations. As these compounds are available as intravenous formulations only, there is growing interest in extended dosing regimens. Although not approved for these agents, this strategy is a rational option, as these compounds have properties suitable for this strategy, including dose-proportional pharmacokinetics, prolonged elimination half-life, and a large therapeutic window. As the use of extended dosing regimens in antifungal prophylaxis is expanding in clinical practice, we reviewed the pharmacokinetic and pharmacodynamic rationale for this strategy, animal model data, dose escalation studies, and clinical trials supporting this concept.

Correlation of fungal cultures from non-sterile sites and Galactomannan assay with the diagnosis of aspergillosis and mucormycosis based on sterile culture results and histopathologic findings

BACKGROUND

Data on whether positive non-sterile fungal culture has the same clinical value as a positive galactomannan (GM) result are limited.

METHODS

Patients with biopsy-proven invasive aspergillosis or mucormycosis (over an 8-year period) in whom the results of GM and fungal culture of sputum and/or sinus aspirates were available were enrolled. Biopsy-proven cases were defined if fungal culture from a sterile biopsy specimen gave a positive result and/or hyphae were demonstrated by immunohistochemical staining for aspergillosis and mucormycosis.

RESULTS

A total of 71 patients comprising 30 biopsy-proven cases of aspergillosis including 13 cases with positive sterile cultures and 41 biopsy-proven cases of mucormycosis including eight cases with positive sterile cultures were enrolled. Of 30 patients with aspergillosis, 15 (50%) revealed Aspergillus spp. growth from non-sterile site and none exhibited the agents of mucormycosis growth from non-sterile site. However, of 41 patients with mucormycosis, eight (20%) revealed the agents of mucormycosis growth from non-sterile site and three (7%) exhibited Aspergillus spp. growth from non-sterile site. In terms of GM assays, 23 (77%) of 30 patients with aspergillosis revealed positive GM results, and 17 (41%) of 41 patients with mucormycosis revealed positive GM assays. So, positive fungal culture from non-sterile site (88% [23/26]) were better correlated with the diagnosis than positive GM assay (57% [23/40]) (p value = .01).

CONCLUSIONS

Positive fungal cultures from non-sterile sites better correlate with the diagnosis of aspergillosis and mucormycosis based on sterile culture results and histopathological findings than positive GM results.

Maxillary Fungal Osteomyelitis: A Review of Literature and Report of a Rare Case

Fungal osteomyelitis is a life-threatening and seldom seen opportunistic infection. It is commonly an affectation of the nose and paranasal sinuses within the orofacial region. It is an aggressive infection that needs to be addressed promptly to prevent fatal consequences. Here, we present a case of a 62-year-old female who presented with complaints of pain and pus discharge from the extraction socket of the left maxillary 23, 24, 25, 26 teeth. She had a history of uncontrolled diabetes mellitus. On further investigation, using diagnostic and Interventional aids, a final diagnosis of maxillary fungal osteomyelitis was made. The infective fungal agents were a mixture of Mucorales and Aspergillus species. A review of all literatures on the subject in the past 13 years using different search engines showed that craniofacial fungal infections with primary maxillary involvement are a rare phenomenon. The primary aim of reporting this case, therefore, is to highlight its rarity, presentation, management and most importantly the outcome of management.

Strategies for Antimicrobial Stewardship in Solid Organ Transplant Recipients

Complications of antimicrobial therapy, such as multidrug-resistant organisms and Clostridium difficile, commonly affect solid-organ transplant recipients and have been associated with graft loss and mortality. Although opportunities are abundant, antimicrobial stewardship practices guiding appropriate therapy have been infrequently reported in transplant patients. A patient-centered, multidisciplinary structure, using established antimicrobial optimization principles, is needed to create nuanced approaches to protect patients and antimicrobials and improve outcomes.

Mixed mold pulmonary infections in haematological cancer patients in a tertiary care cancer centre

There is a paucity of data regarding mixed mold pulmonary infections (MMPIs) in patients with haematological malignancies with or without haematopoietic stem cell transplantation (HSCT). We retrospectively studied 27 such patients (2005-2015) and compared them to patients with invasive pulmonary aspergillosis (IPA) caused by Aspergillus fumigatus. Factors associated with the diagnosis of MMPIs were significant corticosteroid use [20 (74%) vs 6 (22%), P < 0.001], sputum as the source specimen [13 (48%) vs 3 (11%), P = 0.003], younger age (median age: 58 vs 66 years, P = 0.006), and male sex [22 (81%) vs 13 (48%), P = 0.01]. Haematological cancers other than acute myeloid leukaemia (AML)/myelodysplastic syndromes (MDS) were less common in MMPIs than in IPA patients [AML/MDS: 6 (22%) vs 14 (52%), P = 0.04]. Only significant corticosteroid use [95% CI (2.7-42.7), P < 0.001], and sputum as the source specimen [95% (1.6-41.6), P = 0.012] were statistically significant as independently associated with increased risk of MMPIs diagnosis in multivariate analysis. Total mortality rate at day 42 postdiagnosis was comparable in both groups.

Use of (1→3)-β-d-glucan for diagnosis and management of invasive mycoses in HIV-infected patients

People living with HIV (PLHIV) are highly vulnerable to invasive fungal infections (IFIs) due to their immune dysfunction. Diagnosis and treatment of IFIs remain challenging due to the requirement of deep tissue sampling to visualise and culture fungi before initiating treatment. Such techniques are less practical in resource‐limited settings due to their cost and requirement of relatively invasive procedures. Hence, identification of surrogate markers for the early diagnosis and therapeutic monitoring of IFIs is required. Recent studies have shown that (1→3)‐β‐d‐glucan (BDG), a major fungal cell wall antigen, represents a promising soluble marker for the presumptive diagnosis and therapeutic monitoring of IFIs in HIV‐infected patients. Herein, we review findings on the merits of BDG assays in the diagnosis of IFIs and monitoring of antifungal therapies for PLHIV. Conversely to other types of immunocompromised patients, HIV infection is associated with gut damage and subsequent bacterial and fungal translocation leading to elevated BDG plasma levels.

mTOR Modulates CD8+ T Cell Differentiation in Mice with Invasive Pulmonary Aspergillosis

CD8⁺ T cells are a vital component of the adaptive immune system and important for eliminating intracellular pathogens. Notably, mTOR activity is associated with CD8⁺ T effector memory (Tem) cell differentiation in fungal infections. This study investigates the molecular mechanisms of CD8⁺ Tem cell proliferation and differentiation mediated by the mTOR pathway in immunosuppressed mice with invasive pulmonary aspergillosis (IPA). We first established the immunosuppressed IPA mouse model, then mice were subjected to rapamycin treatment daily or interleukin (IL)-12 treatment every other day. Lung tissues and blood samples were obtained seven days later. Aspergillus fumigatus was cultured from the lung tissue of mice inoculated with A. fumigatus spores. After IL-12 treatment, the expression of mTOR and its downstream signaling molecule S6 kinase, number of CD8⁺ Tem cells and interferon-γ expression were significantly increased, while they were significantly decreased after treatment with rapamycin. Additionally, IL-12 treatment induced T-bet but inhibited Eomesodermin expression, while the opposite was seen when the mTOR pathway was blocked by rapamycin. In conclusion, we found that the mTOR pathway induced CD8⁺ T cell proliferation and differentiation by regulating T-bet and Eomesodermin expression, which significantly influenced immune regulation during IPA and enhanced the immune response against fungal infection.

Invasive fungal infections among critically ill children: Epidemiology, risk factors and outcomes

Critically ill children are at high risk of developing invasive fungal infection in a paediatric intensive care unit. This is due to the vulnerability of these children and invasive nature of the care provided.

[Invasive pulmonary aspergillosis]

INTRODUCTION

Invasive pulmonary aspergillosis (IPA) is an important cause of morbidity and mortality in a wide range of patients. Early recognition and diagnosis have become a major focus in improving the management and outcomes of this life-threatening disease.

BACKGROUND

IPA typically occurs during a period of severe and prolonged neutropenia. However, solid organ transplant recipients, patients under immunosuppressive therapy or hospitalized in intensive care units are also at risk. The diagnosis is suspected in the presence of a combination of clinical, biological and CT scan evidence. The microbiological diagnostic strategy should be adapted to the patient's profile. Conventional methods with culture and species identification remain the standard but early diagnosis has been improved by the use of biomarkers such as galactomannan antigen in serum or in bronchoalveolar lavage.

OUTLOOK

The epidemiology of IPA should change with the increased use of antifungal prophylactic regimens and the arrival of targeted therapies. Other microbiological tools, such as PCR and other biomarkers, are currently being assessed.

CONCLUSIONS

IPA must be considered in a wide range of patients. Its prognosis remains poor despite progress in the microbiological diagnosis and therapeutic management.

Feasibility and applicability of antimicrobial stewardship in immunocompromised patients

PURPOSE OF REVIEW

Antimicrobial stewardship is the primary intervention in the battle against antimicrobial resistance, but clinicians do not always apply many key antimicrobial stewardship principles to patients with significant immune defects due to lack of data and fear of bad outcomes. We review evidence regarding the application of stewardship principles to immunocompromised patients, with a focus on solid organ and hematopoietic stem cell transplant recipients.

RECENT FINDINGS

Antimicrobial stewardship programs (ASPs), targeting immunocompromised patient populations such as oncology and transplant, are gaining traction. Emerging literature suggests that several stewardship interventions can be adapted to immunocompromised hosts and improve antimicrobial utilization, but data supporting improved outcomes is very limited.

SUMMARY

The application of antimicrobial stewardship principles to immunocompromised patients is feasible, necessary, and urgent. As antimicrobial stewardship programs gain momentum across a diverse range of healthcare settings more immunocompromised patients will fall under their purview. It is imperative that centers applying antimicrobial stewardship principles share their experience and establish collaborative research efforts to advance our knowledge base in applying antimicrobial stewardship initiatives to immunocompromised host populations, both in terms of programmatic success and patient outcomes.

The limited role of serum galactomannan assay in screening for invasive pulmonary aspergillosis in allogeneic stem cell transplantation recipients on micafungin prophylaxis: a retrospective study

Background

We evaluated the outcomes of serum galactomannan (GM) assay for the screening of invasive pulmonary aspergillosis (IPA) in allogeneic hematopoietic stem cell transplantation (alloHSCT) recipients while on primary antifungal prophylaxis (PAP).

Methods

This study included patients with hematologic disorders who underwent alloHSCT from January 2013 to November 2015. Patients received routine PAP with fluconazole before 2014 and micafungin after 2014; serum GM tests were performed and retrospectively analyzed. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of serum GM tests for detection of probable/proven IPA were evaluated. The serial change of serum GM levels was illustrated on a time series plot.

Results

A total of 136 alloHSCT recipients at Seoul National University Hospital were included in the study. Fluconazole was administered in 72 patients for PAP, while micafungin was administered in the remaining 64 patients. The overall sensitivity, specificity, and NPV of serum GM assays were 95.8% (95% confidence interval [CI] 78.9–99.9%), 93.8% (95% CI 91.7–95.5%), and 99.8% (95% CI 99.1–100.0%), respectively. However, the PPV of GM tests was relatively low at 35.4% (95% CI 23.9–48.2%). The serial change in serum GM levels differed according to the antifungal agents used. With effective PAP using micafungin, serial serum GM levels showed zero order kinetics during the neutropenic period.

Conclusion

Although the serum GM assay is a sensitive and specific test for detecting IPA in alloHSCT recipients, its role for routine surveillance in an era of effective PAP with micafungin is limited.

Fungal Pneumonia in Patients with Hematologic Malignancies and Hematopoietic Cell Transplantation

Invasive fungal infections, which occur primarily as a consequence of prolonged neutropenia and immunosuppression, are a life-threatening complication seen among patients with hematologic malignancies. The routine use of triazole antifungal prophylaxis, enhanced diagnostics, and newer antifungal agents have led to improvements in the care of fungal pneumonias, but invasive fungal infections remain a major cause of morbidity and mortality. This article covers risk factors for major fungal infections, diagnostic approaches, and treatment options for specific fungal pathogens, including Aspergillus and Mucorales species, and discusses current approved strategies for prevention of common and uncommon fungal pneumonias.

Galactofuranose antigens, a target for diagnosis of fungal infections in humans

The use of biomarkers for the detection of fungal infections is of interest to complement histopathological and culture methods. Since the production of antibodies in immunocompromised patients is scarce, detection of a specific antigen could be effective for early diagnosis. D-Galactofuranose (Galf) is the antigenic epitope in glycoconjugates of several pathogenic fungi. Since Galf is not biosynthesized by mammals, it is an attractive candidate for diagnosis of infection. A monoclonal antibody that recognizes Galf is commercialized for detection of aspergillosis. The linkage of Galf in the natural glycans and the chemical structures of the synthesized Galf-containing oligosaccharides are described in this paper. The oligosaccharides could be used for the synthesis of artificial carbohydrate-based antigens, not enough exploited for diagnosis.

D-Galactofuranose (Galf) is the unit in polysaccharides and glycoconjugates of several pathogenic fungi that is recognized by the immune system. Since Galf is not synthesized by mammals, it is an attractive candidate for diagnosis of infection. Since the production of antibodies in immunocompromised patients is scarce, detection of a specific antigen could be effective for early diagnosis. An antibody that recognizes Galf is commercialized for the detection of aspergillosis. Chemically synthesized Galf-containing oligosaccharides, reviewed in this paper, could therefore be used for the synthesis of artificial carbohydrate-based antigens and in diagnosis.

Proteomics as a Tool to Identify New Targets Against Aspergillus and Scedosporium in the Context of Cystic Fibrosis

Cystic fibrosis (CF) is a genetic disorder that increases the risk of suffering microbial, including fungal, infections. In this paper, proteomics-based information was collated relating to secreted and cell wall proteins with potential medical applications from the most common filamentous fungi in CF, i.e., Aspergillus and Scedosporium/Lomentospora species. Among the Aspergillus fumigatus secreted allergens, β-1,3-endoglucanase, the alkaline protease 1 (Alp1/oryzin), Asp f 2, Asp f 13/15, chitinase, chitosanase, dipeptidyl-peptidase V (DppV), the metalloprotease Asp f 5, mitogillin/Asp f 1, and thioredoxin reductase receive a special mention. In addition, the antigens β-glucosidase 1, catalase, glucan endo-1,3-β-glucosidase EglC, β-1,3-glucanosyltransferases Gel1 and Gel2, and glutaminase A were also identified in secretomes of other Aspergillus species associated with CF: Aspergillus flavus, Aspergillus niger, Aspergillus nidulans, and Aspergillus terreus. Regarding cell wall proteins, cytochrome P450 and eEF-3 were proposed as diagnostic targets, and alkaline protease 2 (Alp2), Asp f 3 (putative peroxiredoxin pmp20), probable glycosidases Asp f 9/Crf1 and Crf2, GPI-anchored protein Ecm33, β-1,3-glucanosyltransferase Gel4, conidial hydrophobin Hyp1/RodA, and secreted aspartyl protease Pep2 as protective vaccines in A. fumigatus. On the other hand, for Scedosporium/Lomentospora species, the heat shock protein Hsp70 stands out as a relevant secreted and cell wall antigen. Additionally, the secreted aspartyl proteinase and an ortholog of Asp f 13, as well as the cell wall endo-1,3-β-D-glucosidase and 1,3-β-glucanosyl transferase, were also found to be significant proteins. In conclusion, proteins mentioned in this review may be promising candidates for developing innovative diagnostic and therapeutic tools for fungal infections in CF patients.

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.

Application of Mass Spectrometry Technology to Early Diagnosis of Invasive Fungal Infections

We recently developed a mass spectrometry (MS) procedure based on the detection of a serum disaccharide (MS-DS) in patients with invasive candidiasis (IC). Here, we compare the performance of MS-DS for the diagnosis of IC, invasive aspergillosis (IA), and mucormycosis (MM) with those of commercially available antigen detection tests. This retrospective study included 48 patients (23 IC patients [74 serum samples], 15 IA patients [40 serum samples], and 10 MM patients [15 serum samples]) and 49 appropriate controls (102 serum samples). MS-DS, mannan (Mnn), galactomannan (GM), and (1,3)-β-d-glucan (BDG) were detected by matrix-assisted laser desorption ionization–time of flight (MALDI-TOF) MS, Platelia, and Fungitell assays, respectively. For IC, the sensitivity and specificity of the MS-DS index, BDG detection, and Mnn detection were 62% and 84%, 82% and 60%, and 33% and 94% per serum sample and 83% and 69%, 96% and 31%, and 39% and 86% per patient, respectively. For IA, the corresponding values in comparison to BDG and GM detection were 83% and 81%, 62% and 95%, and 62% and 100% per serum sample and 93% and 76%, 87% and 90%, and 93% and 100% per patient, respectively. Nine of the 10 MM patients had a positive MS-DS result. MS-DS gave an early diagnosis in IC (73% positivity before blood culture), IA (positive before GM detection in six patients), and MM (positivity mainly preceded the date of diagnosis) patients. For IC, persisting MS-DS was associated with a poor prognosis. The different biomarkers were rarely detected simultaneously, suggesting different kinetics of release and clearance. For IA, MS-DS provided better complementation to GM monitoring than BDG monitoring. MS-DS detects panfungal molecules circulating during invasive fungal infections. The performance of MS-DS compared favorably with those of biological tests currently recommended for monitoring at-risk patients. Further validation of this test in multicenter studies is required.

Use of Fungal Diagnostics and Therapy in Pediatric Cancer Patients in Resource-Limited Settings

Fungal diseases are an important cause of mortality in immunocompromised hosts, and their incidence in pediatric cancer patients in low- to middle-income countries is underestimated. In this review, we present relevant, up-to-date information about the most common opportunistic and endemic fungal diseases among children with cancer, their geographic distribution, and recommended diagnostics and treatment. Efforts to improve the care of children with cancer and fungal disease must address the urgent need for sustainable and cost-effective solutions that improve training, fungal disease testing capability, and the use of available resources. We hope that the collective information presented here will be used to advise healthcare providers, regional and country health leaders, and policymakers of the current challenges in diagnosing and treating fungal infections in children with cancer in low- to middle-income countries.

Combined Orofacial Aspergillosis and Mucormycosis: Fatal Complication of a Recurrent Paediatric Glioma-Case Report and Review of Literature

Mucormycosis and aspergillosis are two opportunistic fungal infections, which can evolve into life-threatening complications. They generally affect patients with relevant risk factors such as immunocompromisation or long-term use of antibiotics or corticosteroids. Treatment usually combines medical and surgical approaches, often including extended necrosectomies, although the prognosis of generalized fungal infections is very poor. In this paper, we present the case of a 17-year-old girl affected by combined aspergillosis and mucormycosis, following treatment of a recurrent glioma. The patient was hospitalized for a suspected cellulitis of the right hemi-face, involving frontal maxillary area and the upper airways and was immediately put on intravenous antibiotic therapies; after performing nasal septum and maxillary biopsies, concomitant mucormycosis and aspergillosis were diagnosed and antimycotic therapy with liposomal B-amphotericin was administered. After evaluation by the oral surgeon and otolaryngologist, surgical cranio-facial necrosectomy was suggested, but refused by the parents of the patient. The girl died only few days later, due to a respiratory arrest. Awareness of this pathology with prompt diagnosis and early treatment may improve the outcome of these infections and reduce the mortality.

Changes of serum aspergillus galactomannan during hematopoietic stem cell transplantation in children with prior invasive aspergillosis

Background

Invasive aspergillosis (IA) has recently increased and has a high mortality rate in immunocompromised patients. IA before hematopoietic stem cell transplantation (HSCT) is not uncommon, but how to cope with it is very tough. The serum aspergillus galactomannan antigen (GM) is a helpful marker for diagnosis of IA, and a serial follow-up of GM levels is important to evaluate the response of treatment. However, data on the changes of GM during HSCT are very limited.

Case presentation

Patient 1 was a 2-year-old female with severe aplastic anemia. A typical lung lesion in the computed tomography of the chest with elevated GM levels was noted, and probable IA was diagnosed. After a combination treatment of voriconazole and caspofungin, the GM levels decreased. Although of significant improvement, the pulmonary lesion in the chest X-ray did not disappear before HSCT. The GM levels increased when she received the conditioning regimen during HSCT. The GM levels remained high during the use of steroids for the graft-versus-host disease and declined gradually after tapering off steroids and cyclosporine. Patient 2 was a 12-year-old female with severe aplastic anemia. Voriconazole was administered after the diagnosis of a probable IA. The pulmonary lesions in the chest X-ray disappeared before HSCT. The GM levels flared up during the administration of conditioning regimen and declined after neutrophil engraftment. At present, the two patients were cured of the disease without requiring surgical resection of their pulmonary IA.

Conclusion

To our knowledge, this is the first report about the changes of GM during HSCT in patients with prior IA. With appropriate antifungal therapy and restoration of patient’s immunity, IA can be cured without surgical resection. Further studies are warranted.

Development and Evaluation of a Loop-Mediated Isothermal Amplification Method for Rapid Detection of Aspergillus fumigatus

Aspergillus fumigatusis a conditional pathogen and the major cause of life-threatening invasive aspergillosis (IA) in immunocompromised patients. The early and rapid detection ofA. fumigatusinfection is still a major challenge. In this study, the new member of the fungal annexin family, annexin C4, was chosen as the target to design a loop-mediated isothermal amplification (LAMP) assay for the rapid, specific, and sensitive detection ofA. fumigatus The evaluation of the specificity of the LAMP assay that was developed showed that no false-positive results were observed for the 22 non-A. fumigatusstrains, including 5 species of theAspergillusgenus. Its detection limit was approximately 10 copies per reaction in reference plasmids, with higher sensitivity than that of real-time quantitative PCR (qPCR) at 10(2)copies for the same target. Clinical samples from a total of 69 patients with probable IA (n =14) and possible IA (n= 55) were subjected to the LAMP assay, and positive results were found for the 14 patients with probable IA (100%) and 34 patients with possible IA (61.82%). When detection using the LAMP assay was compared with that using qPCR in the 69 clinical samples, the LAMP assay demonstrated a sensitivity of 89.19% and the concordance rate for the two methods was 72.46%. Accordingly, we report that a valuable LAMP assay for the rapid, specific, and simple detection ofA. fumigatusin clinical testing has been developed.