Detection of circulating galactomannan for the diagnosis and management of invasive aspergillosis

Exploring glycans as vital biological macromolecules: A comprehensive review of advancements in biomedical frontiers

This comprehensive review delves into the intricate landscape of glycans and glycoconjugates, unraveling their multifaceted roles across diverse biological dimensions. From influencing fundamental cellular processes such as signaling, recognition, and adhesion to exerting profound effects at the molecular and genetic levels, these complex carbohydrate structures emerge as linchpins in cellular functions and interactions. The structural diversity of glycoconjugates, which can be specifically classified into glycoproteins, glycolipids, and proteoglycans, underscores their importance in shaping the architecture of cells. Beyond their structural roles, these molecules also play key functions in facilitating cellular communication and modulating recognition mechanisms. Further, glycans and glycoconjugates prove invaluable as biomarkers in disease diagnostics, particularly in cancer, where aberrant glycosylation patterns offer critical diagnostic cues. Furthermore, the review explores their promising therapeutic applications, ranging from the development of glycan-based nanomaterials for precise drug delivery to innovative interventions in cancer treatment. This review endeavors to comprehensively explore the intricate functions of glycans and glycoconjugates, with the primary goal of offering valuable insights into their extensive implications in both health and disease. Encompassing a broad spectrum of biological processes, the focus of the review aims to provide a comprehensive understanding of the significant roles played by glycans and glycoconjugates.

Serial Bronchoalveolar Lavage Fluid Aspergillus Galactomannan and Treatment Response in Invasive Pulmonary Aspergillosis

We studied patients diagnosed with aspergillosis based on positive bronchoalveolar lavage (BAL) Aspergillus galactomannan (GM) who had follow-up BAL sampling within 180 days. GM trend and clinical outcome were concordant in only 60% (30/50). While useful for the initial diagnosis, BAL GM trending does not always correlate with treatment response.

Implementation of Lateral Flow Assays for the Diagnosis of Invasive Aspergillosis in European Hospitals: A Survey from Belgium and a Literature Review of Test Performances in Different Patient Populations

OBJECTIVES

Diagnosis of invasive aspergillosis is based on a combination of criteria, of which the detection of Aspergillus galactomannan (GM) often is decisive. To date, the most commonly used method to determine GM is an enzyme-linked immune assay (EIA). But since a few years lateral flow assays (LFAs) were introduced, providing the possibility for rapid single sample testing. More and more LFAs are entering the market, but, although often being equated, all use their own antibodies, procedures and interpretation criteria. A recent European survey revealed that about 24-33% of laboratories implemented a lateral flow assay on-site.

METHODS

We conducted a survey at 81 Belgian hospital laboratories regarding the implementation of LFAs in their centre. In addition, we performed an extensive review of all publicly available studies on the performance of lateral flow assays to diagnose invasive aspergillosis.

RESULTS

Response rate to the survey was 69%. Of the 56 responding hospital laboratories, 6 (11%) used an LFA. The Soña Aspergillus galactomannan LFA (IMMY, Norman, Oklahoma, USA) was used in 4/6 centres, while two centres used the QuicGM (Dynamiker, Tianjin, China) and one centre used the FungiXpert Aspergillus Galactomannan Detection K-set LFA (Genobio [Era Biology Technology], Tianjin, China). One centre used 2 distinct LFAs. In 3/6 centres, the sample is sent to another lab for confirmation with GM-EIA when the LFA result is positive and in 2/6 when the LFA results is negative. In one centre, a confirmatory GM-EIA is always performed in house. In three centres the LFA result is used as a complete substitute for GM-EIA. Available LFA performance studies are very diverse and results vary in function of the study population and type of LFA. Apart from the IMMY and OLM LFA, only very limited performance data are available. From two out of three LFAs used in Belgium, no clinical performance studies are published in literature.

CONCLUSIONS

A large variety of LFAs are used in Belgian Hospitals, some of which no clinical validation studies are published. These results do likely have implications for other parts of Europe and for the rest of the world as well. Due to the variable performance of LFA tests and the limited validation data available, each laboratory must check the available performance information of the specific test considered for implementation. In addition, laboratories should perform an implementation verification study.

APPLICATION OF A NOVEL ASPERGILLUS LATERAL-FLOW DEVICE IN THE DIAGNOSIS OF ASPERGILLOSIS IN CAPTIVE GENTOO PENGUINS (PYGOSCELIS PAPUA PAPUA)

Aspergillosis is the primary fungal disease affecting captive penguins globally. Its diagnosis remains challenging, and currently no tests are both sensitive and specific for the detection of early infection. The present study evaluated a recently developed Aspergillus lateral-flow device (AspLFD) for the detection of Aspergillus spp. antigen in plasma and glottis mucus from captive penguins. In a pilot retrospective study, banked frozen plasma samples from captive penguins were reviewed: samples from 11 gentoo penguins (Pygoscelis papua papua) and 4 king penguins (Aptenodytes patagonicus) fulfilled the inclusion criteria and were used in the analysis. Positive plasma AspLFD test results were found in 80% (four of five) of the aspergillosis-positive cases tested. All of the aspergillosis-negative cases tested negative (10 of 10) on the AspLFD test. In a cohort prospective study, paired plasma and glottis swab samples were opportunistically and nonrandomly collected from captive gentoo penguins. In total, 26 penguins were tested. In the negative control group, AspLFD test was negative on plasma and swab in 100% of birds (14 of 14). In the aspergillosis-positive group, AspLFD test was positive on plasma samples from 33% (4 of 12) of birds, on swab samples from 50% (6 of 12) of birds, and on either plasma or swab samples from 75% (9 of 12) of birds. The AspLFD is currently used for the diagnosis of aspergillosis in humans and also shows promise for use in penguins. Larger prospective studies are recommended.

Galactomannan-Antigen Testing from Non-Directed Bronchial Lavage for Rapid Detection of Invasive Pulmonary Aspergillosis in Critically Ill Patients: A Proof-of-Concept Study

Invasive pulmonary aspergillosis is associated with high mortality. For diagnosis, galactomannan-antigen in serum and bronchoalveolar lavage fluid is recommended, with higher sensitivity in bronchoalveolar lavage fluid. Because of invasiveness, bronchoalveolar lavage might be withheld due to patients' or technical limitations, leading to a delay in diagnosis while early diagnosis is crucial for patient outcome. To address this problem, we performed an analysis of patient characteristics of intubated patients with invasive pulmonary aspergillosis with comparison of galactomannan-antigen testing between non-directed bronchial lavage (NBL) and bronchoalveolar lavage fluid. A total of 32 intubated ICU patients with suspected invasive pulmonary aspergillosis could be identified. Mycological cultures were positive in 37.5% for A. fumigatus. Galactomannan-antigen in NBL (ODI 4.3 ± 2.4) and bronchoalveolar lavage fluid (ODI 3.6 ± 2.2) showed consistent results (p-value 0.697). Galactomannan-antigen testing for detection of invasive pulmonary aspergillosis using deep tracheal secretion showed comparable results to bronchoalveolar lavage fluid. Because of widespread availability in intubated patients, galactomannan-antigen from NBL can be used as a screening parameter in critical risk groups with high pretest probability for invasive aspergillosis to accelerate diagnosis and initiation of treatment. Bronchoalveolar lavage remains the gold standard for diagnosis of invasive aspergillosis to be completed to confirm diagnosis, but results from NBL remove time sensitivity.

Sensitive Detection of the Human Epididymis Protein-4 (HE4) Ovarian Cancer Biomarker through a Sandwich-Type Immunoassay Method with Laser-Induced Breakdown Spectroscopy

Detection of cancer before the appearance of any symptoms is crucial for successful treatment. Early detection is, however, very challenging, particularly for the types of cancer with few or no symptoms at early stages, such as epithelial ovarian cancer (EOC). Developing a user-friendly method that can detect biomarkers with sufficient selectivity, sensitivity, and reproducibility is a promising approach for overcoming the challenges of early detection of EOC. In this study, we report a sandwich-type microparticle immunoassay for sensitive detection of the HE4 biomarker with laser-induced breakdown spectroscopy. Here, we cross-linked elemental particles to a specific functional group of the targeted biomolecules based on a covalent and non-covalent linking chemistry to improve the sensitivity and selectivity of biomarker detection, in which Fe₃O₄ and SiO₂ microparticles were used to conjugate and purify the antibody-antigen in complex media. Simultaneous detection of Fe and Si from a magnetically purified assay significantly improves the HE4 biomarker's detectability, in which HE4 was detected with a limit of detection of 0.0022 pM. We also determined the coupling ratio between HE4 and silica particles using a silicon calibration curve.

The Role of Serum Galactomannan Assay as a Potential Surrogate Biomarker for Fungal Microinvasion in Allergic Fungal Rhinosinusitis

We conducted this study to determine if serum galactomannan (GM) can be used as a marker to implicate the invasiveness of allergic fungal rhinosinusitis (AFRS), and correlate this value with the aggressiveness of disease documented via computed tomography (CT). All paranasal CT scans done for AFRS patients prospectively over a five-year period (2015-2019) were included. An indigenous 20-point score was used to document the extent of bone erosion seen on CT, wherein a higher score meant a greater extent of bone erosion. It was then correlated with serum GM scores. The median CT scores of galactomannan-positive (GM+) patients were compared with the median CT scores of galactomannan-negative (GM-) patients 3 using Mann-Whitney U test. The patients were divided into five groups based on the extent of disease-No bone erosion, erosion of only sinus wall/orbit, 3 erosion of orbit and skull base, erosion of only skull base and lateral extension of disease into infratemporal fossa (ITF). Subgroup analysis was conducted over mean GM values in these groups using ANOVA test. p-value < 0.05 was considered significant. Statistical analysis was performed using SPSS version 25.0. A total of 92 patients were included (56 males, 36 females). No statistically significant difference was found (p-value = 0.42) between the CT scores of galactomannan-positive (GM+) group and galactomannan-negative (GM-) group. The mean GM scores amongst the five sub-groups did not show a statistically significant difference. Serum galactomannan values correlate poorly with aggressiveness of disease quantified on non-contrast CT of paranasal sinuses.

Antifungal antibodies present in intravenous immunoglobulin derived from China

Fungal infections usually occur in immunocompromised patients. Intravenous immunoglobulin (IVIG) has been used as therapeutic interventions for many infectious diseases, but seldom applied in mycosis due to unknown antifungal specificity. This study aims to determine the presence of antifungal antibodies in IVIG. Binding reactivity of IVIG with crude and recombinant antigens of Candida albicans, Aspergillus fumigatus, Cryptococcus neoformans and Talaromyces marneffei were observed in a dose-dependent manner, similar with mixed normal human sera. The antifungal specificity was further confirmed by competitive enzyme-linked immunosorbent assays (ELISA) inhibited by rabbit specific antifungal polyclonal antibodies (PAbs) and homogenous crude antigens with inhibitions of 65.5-87.2% and 73.1-94.2%, respectively. Moreover, IVIG also reacted with fungal glycoproteins (Csa2, Cpl1 and Mp1p) in a dose-dependent way, which was inhibited by specific rabbit PAbs and homogenous antigens with different inhibitions and pulled down 72.8-83.8% of specific antibodies if preabsorption IVIG with Dynabeads® coupled with homogenous glycoproteins. These results furthermore verified the antifungal specificity of IVIG. Among four brands of IVIG, there was different antifungal IgG against C. albicans (P < 0.05) and C. neoformans (P < 0.05), while no difference for A. fumigatus (P = 0.086) and T. marneffei (P = 0.057). IVIG contained a significantly higher level of specific IgG for C. albicans than other three fungi (P <0.001). In conclusion, we proved antifungal IgG against C. albicans, A. fumigatus, C. neoformans and T. marneffei present in IVIG, which might be expected to provide a possible immunoregulation choice for mycosis and an evaluation to humoral immunity against fungi.

Empiric vs Preemptive Antifungal Strategy in High-Risk Neutropenic Patients on Fluconazole Prophylaxis: A Randomized Trial of the European Organization for Research and Treatment of Cancer

BACKGROUND

Empiric antifungal therapy is considered the standard of care for high-risk neutropenic patients with persistent fever. The impact of a preemptive, diagnostic-driven approach based on galactomannan screening and chest computed tomography scan on demand on survival and on the risk of invasive fungal disease (IFD) during the first weeks of high-risk neutropenia is unknown.

METHODS

Patients with acute myeloid leukemia (AML) or myelodysplastic syndrome (MDS) and allogeneic hematopoietic cell transplant recipients were randomly assigned to receive caspofungin empirically (arm A) or preemptively (arm B), while receiving fluconazole 400 mg daily prophylactically. The primary end point of this noninferiority study was overall survival (OS) 42 days after randomization.

RESULTS

Of 556 patients recruited, 549 were eligible: 275 in arm A and 274 in arm B. Eighty percent of the patients had AML or MDS requiring high-dose chemotherapy, and 93% of them were in the first induction phase. At day 42, the OS was not inferior in arm B (96.7%; 95% confidence interval [CI], 93.8%-98.3%) when compared with arm A (93.1%; 95% CI, 89.3%-95.5%). The rates of IFDs at day 84 were not significantly different, 7.7% (95% CI, 4.5%-10.8%) in arm B vs 6.6% (95% CI, 3.6%-9.5%) in arm A. The rate of patients who received caspofungin was significantly lower in arm B (27%) than in arm A (63%; P < .001).

CONCLUSIONS

The preemptive antifungal strategy was safe for high-risk neutropenic patients given fluconazole as prophylaxis, halving the number of patients receiving antifungals without excess mortality or IFDs. Clinical Trials Registration. NCT01288378; EudraCT 2010-020814-27.

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

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

Pacemaker Associated Aspergillus fumigatus Endocarditis: A Case Report

Aspergillus endocarditis (AE) is a highly fatal infection that can occur in heart valve replacement, pacemaker implantation and other heart surgeries, and early recognition and sufficient diagnosis are challenging. Here, we report the case of a 68-year-old male with a history of dilated cardiomyopathy and pacemaker implantation who had a repeated fever with failed antibacterial treatment and sterile blood culture. He developed endocarditis, and the culture and biopsy of vegetation tissue showed the abundant presence of septate hyphae, which was subsequently identified as Aspergillus fumigatus by internal transcribed spacer (ITS) sequencing. Although the patient had serious side effects from voriconazole, he had a good prognosis following surgery and prolonged caspofungin antifungal therapy of 42 consecutive days. We discuss the diagnosis and treatment strategy of AE, and recommend galactomannan assays and next-generation sequencing for a timely diagnosis. Early surgical intervention combined with prompt antifungal therapy appears significant for survival.

Invasive Aspergillosis in the Intensive Care Unit

Invasive pulmonary aspergillosis (IPA) is a serious condition resulting in significant mortality and morbidity among patients in intensive care units (ICUs). There is a growing number of at-risk patients for this condition with the increasing use of immunosuppressive therapies. The diagnosis of IPA can be difficult in ICUs, and relies on integration of clinical, radiological, and microbiological features. In this review, we discuss patient populations at risk for IPA, as well as the diagnostic criteria employed. We review the fungal biomarkers used, as well as the challenges in distinguishing colonization with Aspergillus from invasive disease. We also address the growing concern of multidrug-resistant Aspergillosis and review the new and novel therapeutics which are in development to combat this.

Existing tests vs. novel non-invasive assays for detection of invasive aspergillosis in patients with respiratory diseases

BACKGROUND

Although existing mycological tests (bronchoalveolar lavage [BAL] galactomannan [GM], serum GM, serum (1,3)-β-D-glucan [BDG], and fungal culture) are widely used for diagnosing invasive pulmonary aspergillosis (IPA) in non-hematological patients with respiratory diseases, their clinical utility in this large population is actually unclear. We aimed to resolve this clinical uncertainty by evaluating the diagnostic accuracy and utility of existing tests and explore the efficacy of novel sputum-based Aspergillus assays.

METHODS

Existing tests were assessed in a prospective and consecutive cohort of patients with respiratory diseases in West China Hospital between 2016 and 2019 while novel sputum assays (especially sputum GM and Aspergillus-specific lateral-flow device [LFD]) in a case-controlled subcohort. IPA was defined according to the modified European Organization for Research and Treatment of Cancer/Mycoses Study Group criteria. Sensitivity and specificity were computed for each test and receiver operating characteristic (ROC) curve analysis was performed.

RESULTS

The entire cohort included 3530 admissions (proven/probable IPA = 66, no IPA = 3464) and the subcohort included 127 admissions (proven/probable IPA = 38, no IPA = 89). Sensitivity of BAL GM (≥1.0 optical density index [ODI]: 86% [24/28]) was substantially higher than that of serum GM (≥0.5 ODI: 38% [39/102]) ( χ2  = 19.83, P   <  0.001), serum BDG (≥70 pg/mL: 33% [31/95]) ( χ2  = 24.65, P  < 0.001), and fungal culture (33% [84/253]) ( χ2  = 29.38, P  < 0.001). Specificity varied between BAL GM (≥1.0 ODI: 94% [377/402]), serum GM (≥0.5 ODI: 95% [2130/2248]), BDG (89% [1878/2106]), and culture (98% [4936/5055]). Sputum GM (≥2.0 ODI) had similar sensitivity (84% [32/38]) (Fisher's exact P  = 1.000) to and slightly lower specificity (87% [77/89]) ( χ2  = 5.52, P  = 0.019) than BAL GM (≥1.0 ODI). Area under the ROC curve values were comparable between sputum GM (0.883 [0.812-0.953]) and BAL GM (0.901 [0.824-0.977]) ( P  = 0.734). Sputum LFD had similar specificity (91% [81/89]) ( χ2  = 0.89, P  = 0.345) to and lower sensitivity (63% [24/38]) ( χ2  = 4.14, P  = 0.042) than BAL GM (≥1.0 ODI), but significantly higher sensitivity than serum GM (≥0.5 ODI) ( χ2  = 6.95, P  = 0.008), BDG ( χ2  = 10.43, P  = 0.001), and fungal culture ( χ2  = 12.70, P  < 0.001).

CONCLUSIONS

Serum GM, serum BDG, and fungal culture lack sufficient sensitivity for diagnosing IPA in respiratory patients. Sputum GM and LFD assays hold promise as rapid, sensitive, and non-invasive alternatives to the BAL GM test.

Noninvasive Testing and Surrogate Markers in Invasive Fungal Diseases

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

Unique presentations of aspergillosis endogenous endophthalmitis in two hospitalized patients with severe COVID-19

We present two ICU-hospitalized patients with coronavirus disease-19 (COVID-19) presenting with endogenous endophthalmitis in one eye and variable manifestations of chorioretinitis in the fellow eye. Two diabetic patients (57 and 62 years old) showed anterior uveitis and yellowish-white subretinal infiltrations. The fellow eye of one patient showed patches of choroiditis, while the other showed full retinal thickness infiltrations. A workup yielded high serum titers of galactomannan, diagnostic of aspergillosis. The widespread use of high doses of corticosteroids in the management of COVID-19 may predispose to various secondary fungal opportunistic infections and may manifest in different forms of chorioretinal infiltration.

Exhaled Volatile Organic Compounds for Identifying Patients With Chronic Pulmonary Aspergillosis

Background: Diagnosing chronic pulmonary aspergillosis is a major challenge in clinical practice. The development and validation of a novel, sensitive and specific assay for diagnosing chronic pulmonary aspergillosis is urgently needed.

Methods: From April 2018 to June 2019, 53 patients with chronic pulmonary aspergillosis (CPA), 32 patients with community-acquired pneumonia (CAP) and 48 healthy controls were recruited from the First Affiliated Hospital of Guangzhou Medical University. Clinical characteristics and samples were collected at enrollment. All exhaled breath samples were analyzed offline using thermal desorption single-photon ionization time-of-flight mass spectrometry; to analyze the metabolic pathways of the characteristic volatile organic compounds, serum samples were subjected to ultrahigh-performance liquid chromatography.

Results: We identified characteristic volatile organic compounds in patients with chronic pulmonary aspergillosis, which mainly consisted of phenol, neopentyl alcohol, toluene, limonene and ethylbenzene. These compounds were assessed using a logistic regression model. The sensitivity and specificity were 95.8 and 96.9% for discriminating patients in the CPA group from those in the CAP group and 95.8 and 97.9% for discriminating patients in the CPA group from healthy controls, respectively. The concentration of limonene (m/z 136) correlated significantly positively with anti-Aspergillus fumigatus IgG antibody titers (r = 0.420, P < 0.01). After antifungal treatment, serum IgG and the concentration of limonene (m/z 136) decreased in the subgroup of patients with chronic pulmonary aspergillosis.

Conclusions: We identified VOCs that can be used as biomarkers for differential diagnosis and therapeutic response prediction in patients with chronic pulmonary aspergillosis.

Development of a Method of Measuring β-D-Glucan and Its Use in Preemptive Therapy for Invasive Fungal Infections

Invasive fungal infections (IFIs) are serious infections that develop in conjunction with neutropenia after chemotherapy for acute leukemia or with hematopoietic stem cell transplantation. Conventionally, empirical antifungal therapy was recommended to treat IFIs for patient safety despite a lack of evidence of fungal infections. However, many studies have indicated that antifungals were not necessary for over half of patients, and several detriments of empirical therapy were noted, e.g., antifungals caused adverse reactions, an increase in drug-resistant fungi was a possibility, and medical costs soared. β-D-glucan (BDG) is a component of clinically important fungi such as Aspergillus and Candida. The G-test was developed in Japan as a way to measure BDG in serum using a coagulation factor from the blood of the horseshoe crab. Pre-emptive antifungal therapy based upon serodiagnosis with a BDG or galactomannan assay and CT imaging has been introduced. With pre-emptive antifungal therapy, the prognosis is equivalent to that with empirical therapy, and the dose of the antifungal has been successfully reduced. Measurement of BDG has been adopted widely as a method of diagnosing IFIs and is listed in the key guidelines for fungal infections and febrile neutropenia.

Challenges with Utilizing the 1,3-Beta-d-Glucan and Galactomannan Assays To Diagnose Invasive Mold Infections in Immunocompromised Children

Establishing the diagnosis of invasive mold infections (IMI) in immunocompromised children is challenging due to nonspecific clinical presentations and the limited sensitivity of traditional culture-based methods. Rapid non-culture-based diagnostics such as the 1,3-beta-d-glucan and galactomannan assays have emerged as promising adjuncts to conventional diagnostic tests in adults. Available data suggest that 1,3-beta-d-glucan has limited accuracy in the pediatric population and is not recommended to be used for the diagnosis of IMI in children. On the other hand, the diagnostic performance of the serum and bronchoalveolar lavage galactomannan in immunocompromised children is comparable to results observed in adults and can be used as a screening tool in children at high risk of developing invasive aspergillosis (IA) who are not receiving mold-active antifungal prophylaxis and as a diagnostic tool in symptomatic children suspected of having IA. Herein, we summarize the available evidence for the use of these rapid non-culture-based diagnostics in immunocompromised children. We also summarize potential causes of false positivity for the 1,3-beta-d-glucan and galactomannan assays.

Serum galactomannan level for the diagnosis of invasive pulmonary aspergillosis in hospitalized patients with chronic obstructive pulmonary disease (COPD): Meta-analysis

Background: The serum galactomannan (GM) assay is used to diagnose invasive pulmonary aspergillosis (IPA). We conducted a meta-analysis to assess the overall accuracy of the serum GM test for detecting IPA in critically ill COPD patients.

Methods: The web of science, Pubmed, Embase, China National Knowledge Infrastructure, WanFang, Weipu (VIP) Science China databases were searched for all the eligible studies, including randomized controlled trials and prospective studies up to February 2019. We selected and assessed articles that reported diagnostic data related to serum GM for diagnosis of invasive fungal disease in hospitalized COPD patients. Additionally, pooled sensitivity (SEN), specificity (SPE), true positive (TP), false positive (FP), true negative (TN), false negative (FN) were estimated for summarizing overall test performance.

Results: Of 1104 articles screened, 14 studies were involved in the meta-analysis with 1127 patients in the COPD serum sample. The pooled serum GM assay results with cutoff value of 0.5 were as follows: DOR: 15 (95% CI, 6–38), sensitivity: 0.57 (95% CI, 0.37–0.75), specificity: 0.92 (95%,CI, 0.85–0.96), and the SROC was 0.89 (95% CI, 0.86–0.91). When the cutoff value was 1, the results were as follows: DOR: 33 (95% CI, 15–70), sensitivity: 0.57 (95% CI, 0.39–0.73), specificity: 0.96 (95% CI, 0.93–0.98), and SROC was 0.95 (95% CI, 0.92–0.96).

Conclusion: Serum GM can be used to assist in diagnosis of IPA in critically ill COPD patients. When cutoff value was set as 1, serum GM had better diagnostic value compared to those with cutoff of 0.5.

Comparative Analysis of Clinical Parameters and Sputum Biomarkers in Establishing the Relevance of Filamentous Fungi in Cystic Fibrosis

Background

The relationship between fungal culture (FC) positivity and airway inflammation in CF is largely unknown. Identifying the clinical significance of filamentous fungi in CF using both clinical parameters and biomarkers may change our antimicrobial therapeutic strategies.

Objectives

To investigate the clinical characteristics and airway biomarker profile in relation to the detection of filamentous fungi in respiratory samples obtained from CF patients.

Methods

A prospective cohort study over 24 months, including children and adults with CF. Participants provided sputum and/or bronchoalveolar lavage samples, which underwent processing for bacterial and fungal culture, leukocyte differential cell count and biomarker analysis for neutrophil elastase (NE), interleukin-8 (IL-8), galactomannan and tumor necrosis factor receptor type 2 (TNF-R2). We performed FC using neat sputum plugs, an approach shown to be more sensitive compared to routine laboratory testing.

Results

Sixty-one patients provided 76 respiratory samples (72 sputum and 4 BAL). Median age was 17 years (range 6 months-59 years). FC positivity was noted in 49% of the cohort. FC positivity was greater during pulmonary exacerbation compared to the stable state (67 versus 50%). Participants aged 5-30 years had a lower FEV1 within the FC positive group. A significant association between FC positivity and non-tuberculosis mycobacterial (NTM) culture was observed on non-parametric testing (p = 0.022) and regression analysis (p = 0.007). Exposure to indoor mold was a predictor for FC positivity (p = 0.047). There was a trend towards increased lung clearance index (LCI), bronchiectasis and intravenous antibiotic use in the FC positive group. There was no significant difference in biomarkers between FC positive and negative patients.

Conclusion

Aspergillus. fumigatus is the commonest filamentous fungi cultured from CF airways. We found no difference in the airway biomarker profile between FC positive and negative patients. The role of galactomannan and TNFR2 as fungal specific biomarkers in CF remains uncertain. FC positivity is associated with a lower FEV₁ in younger patients, a lower LCI, NTM positivity, bronchiectasis, and intravenous antibiotic exposure. Larger trials are needed to determine the role of galactomannan and TNF-R2 as potential fungal biomarkers in CF.

The putative polysaccharide synthase AfCps1 regulates Aspergillus fumigatus morphogenesis and conidia immune response in mouse bone marrow-derived macrophages

Aspergillus fumigatus is a well-known opportunistic pathogen that causes invasive aspergillosis (IA) infections with high mortality in immunosuppressed individuals. Morphogenesis, including hyphal growth, conidiation, and cell wall biosynthesis is crucial in A. fumigatus pathogenesis. Based on a previous random insertional mutagenesis library, we identified the putative polysaccharide synthase gene Afcps1 and its para-log Afcps2. Homologs of the cps gene are commonly found in the genomes of most fungal and some bacterial pathogens. Afcps1/cpsA is important in sporulation, cell wall composition, and virulence. However, the precise regulation patterns of cell wall integrity by Afcps1/cpsA and further effects on the immune response are poorly understood. Specifically, our in-depth study revealed that Afcps1 affects cell-wall stability, showing an increased resistance of ΔAfcps1 to the chitinmicrofibril destabilizing compound calcofluor white (CFW) and susceptibility of ΔAfcps1 to the β-(1,3)-glucan synthase inhibitor echinocandin caspofungin (CS). Additionally, deletion of Afcps2 had a normal sporulation phenotype but caused hypersensitivity to Na⁺ stress, CFW, and Congo red (CR). Specifically, quantitative analysis of cell wall composition using high-performance anion exchange chromatography-pulsed amperometric detector (HPAEC-PAD) analysis revealed that depletion of Afcps1 reduced cell wall glucan and chitin contents, which was consistent with the down-regulation of expression of the corresponding biosynthesis genes. Moreover, an elevated immune response stimulated by conidia of the ΔAfcps1 mutant in marrow-derived macrophages (BMMs) during phagocytosis was observed. Thus, our study provided new insights into the function of polysaccharide synthase Cps1, which is necessary for the maintenance of cell wall stability and the adaptation of conidia to the immune response of macrophages in A. fumigatus.

Bronchoalveolar lavage fluid and serum 1,3-β-D-glucan testing for invasive pulmonary aspergillosis diagnosis in hematological patients: the role of factors affecting assay performance

Invasive fungal disease (IFD) early diagnosis improves hematological patient survival. Non-culture-based methods may reduce diagnostic time to identify IFD. As complex data on the value of 1,3-β-D-glucan (BDG) from bronchoalveolar lavage fluid (BALF) compared to serum for the most frequent invasive pulmonary aspergillosis (IPA) diagnosis are scarce, particularly including evaluation of potential factors adversely affecting BDG assay, we provided prospective single-center analysis evaluating 172 episodes of pulmonary infiltrates with BDG detection in BALF and serum samples collected in parallel among hematological patients from 2006 to 2015. Proven and probable IPA were documented in 13.4% of the episodes. Sensitivity (SEN), specificity (SPE), positive and negative predictive value (PPV; NPV), and diagnostic odds ratio (DOR) of the BDG assay using standard (80 pg/ml) cut-off for BALF were: 56.5%; 83.2%; 34.2%; 92.5%, and 6.5, respectively, and for serum were: 56.5%; 82.6%; 33.3%; 92.5%, and 6.2, respectively. The same BDG assay parameters employing a calculated optimal cut-off for BALF (39 pg/ml) were: 78.3%; 72.5%; 30.5%; 95.6%, and 9.5, respectively; and for serum (40 pg/ml) were: 73.9%; 69.1%; 27.0%; 94.5%, and 6.3, respectively. While identifying acceptable SEN, SPE, and DOR, yet low PPV of both BALF and serum BDG assay for IPA diagnosis, neither the combination of both materials nor the new optimal BDG cut-off led to significant test quality improvement. Absolute neutrophil count and aspirated BALF volume with a significant trend affected BDG assay performance. The BDG test did not outperform galactomannan assay.

Prospective observational study of respiratory Aspergillus colonization or disease in patients with various stages of chronic obstructive pulmonary disease utilizing culture versus nonculture techniques

Chronic obstructive pulmonary disease (COPD) patients have been recognized to be at increased risk of Aspergillus spp. colonization, which may progress to invasive pulmonary aspergillosis (IPA). The objective of this study was to determine the frequency of Aspergillus colonization, or disease, in a cohort of COPD patients. A prospective observational study was undertaken to determine Aspergillus colonization, or disease, in consecutive COPD patients undergoing bronchoscopy. Fungal culture as well as galactomannan antigen (GM) and Aspergillus nucleic acid detection (PCR) were performed on bronchoalveolar lavage fluid (BAL) samples. One hundred and fifty patients were recruited. One hundred and twelve (74.7%) were outpatients, 38 (25.33%) were inpatients, of whom 6 (4%) were in the intensive care unit. Most patients (N = 122, 81.3%) were either COPD GOLD (Global Initiative for Chronic Obstructive Lung Disease) stages 1 or 2. Nine (6%) patients were on systemic steroids, 64 (42.7%) on inhaled steroids, and 9 (6%) on both. Seventeen patients (11.3%) had at least one positive test for Aspergillus detection (culture ± galactomannan ± polymerase chain reaction [PCR]), 13 (76.4%) of whom were COPD GOLD stages 1 or 2.  Five patients had probable or putative IPA. Aspergillus sp. was detected in five patients (3.3%) by culture, but detection increased to 17 (11.3%) by the additional testing for GM or Aspergillus DNA. The frequency of Aspergillus detection in this cohort of COPD patients may reflect the predominance of early GOLD stages among the study population but deserves further investigation to determine its relevance as a predictive risk factor for IPA.

LAY SUMMARY

COPD is a risk factor for Aspergillus spp. colonization. Bronchoalveolar lavage samples of 150 COPD patients were tested for presence of Aspergillus fumigatus, which was detected in five patients (3.3%) by culture, but detection of Aspergillus increased to 17 (11.3%) by additional GM and PCR testing.

Evaluation of quantitative real-time PCR and Platelia galactomannan assays for the diagnosis of disseminated Talaromyces marneffei infection

Talaromyces (Penicillium) marneffei is an emerging pathogen that causes significant morbidity and mortality in immunocompromised patients in endemic regions such as southeast Asia. The diagnosis of disseminated T. marneffei infection remains challenging in clinical practice. In the study, a well-validated real-time quantitative polymerase chain reaction (qPCR) target region of ITS1-5.8S-ITS2 and a Platelia galactomannan (GM) assay were compared for their diagnostic performance using serum samples from patients with or without human immunodeficiency virus (HIV). The results showed that this novel qPCR method is highly sensitive and specific for T. marneffei DNA detection in serum samples, and the limit of detection and species-specificity of qPCR were five copies of DNA and 100%, respectively. For detection in serum samples from 36 talaromycosis patients, the sensitivity of qPCR was 86.11% (31/36), including 20/20 (100%) patients with fungemia and 11/16 (68.75%) patients without fungemia. For the GM assay, the sensitivity was 80.56% (29/36) when the GM optical density cutoff index was ≥0.5, including 19/20 (95%) patients with fungemia and 10/16 (62.5%) patients without fungemia. These results indicate that the novel qPCR and GM assays can be used as a valuable tool in the diagnosis of T. marneffei infection. Serum samples are convenient hematological specimens for T. marneffei DNA quantification. Combining the GM assay and qPCR is more scientific and appropriate for diagnosing T. marneffei infection in endemic areas.

Revision and Update of the Consensus Definitions of Invasive Fungal Disease From the European Organization for Research and Treatment of Cancer and the Mycoses Study Group Education and Research Consortium

BACKGROUND

Invasive fungal diseases (IFDs) remain important causes of morbidity and mortality. The consensus definitions of the Infectious Diseases Group of the European Organization for Research and Treatment of Cancer and the Mycoses Study Group have been of immense value to researchers who conduct clinical trials of antifungals, assess diagnostic tests, and undertake epidemiologic studies. However, their utility has not extended beyond patients with cancer or recipients of stem cell or solid organ transplants. With newer diagnostic techniques available, it was clear that an update of these definitions was essential.

METHODS

To achieve this, 10 working groups looked closely at imaging, laboratory diagnosis, and special populations at risk of IFD. A final version of the manuscript was agreed upon after the groups' findings were presented at a scientific symposium and after a 3-month period for public comment. There were several rounds of discussion before a final version of the manuscript was approved.

RESULTS

There is no change in the classifications of "proven," "probable," and "possible" IFD, although the definition of "probable" has been expanded and the scope of the category "possible" has been diminished. The category of proven IFD can apply to any patient, regardless of whether the patient is immunocompromised. The probable and possible categories are proposed for immunocompromised patients only, except for endemic mycoses.

CONCLUSIONS

These updated definitions of IFDs should prove applicable in clinical, diagnostic, and epidemiologic research of a broader range of patients at high-risk.

Digestive enzymes of fungal origin as a relevant cause of false positive Aspergillus antigen testing in intensive care unit patients

Background

Galactomannan antigen (GM) testing is widely used in the diagnosis of invasive aspergillosis (IA). Digestive enzymes play an important role in enzyme substitution therapy in exocrine pancreatic insufficiency. As digestive enzymes of fungal origin like Nortase contain enzymes from Aspergillus, a false-positive result of the test might be possible because of cross-reacting antigens of the cell wall of the producing fungi. We, therefore, asked whether the administration of fungal enzymes is a relevant cause of false-positive GM antigen test results.

Methods

Patients with a positive GM antigen test between January 2016 and April 2020 were included in the evaluation and divided into two groups: group 1—Nortase-therapy, group 2—no Nortase-therapy. In addition, dissolved Nortase samples were analyzed in vitro for GM and β-1,3-D-glucan. For statistical analysis, the chi-squared and Mann‒Whitney U tests were used.

Results

Sixty-five patients were included in this evaluation (30 patients receiving Nortase and 35 patients not receiving Nortase). The overall false positivity rate of GM testing was 43.1%. Notably, false-positive results were detected significantly more often in the Nortase group (73.3%) than in the control group (17.1%, p < 0.001). While the positive predictive value of GM testing was 0.83 in the control group, there was a dramatic decline to 0.27 in the Nortase group. In vitro analysis proved that the Nortase enzyme preparation was highly positive for the fungal antigens GM and β-1,3-D-glucan.

Conclusions

Our data demonstrate that the administration of digestive enzymes of fungal origin like Nortase leads to a significantly higher rate of false-positive GM test results compared to that in patients without digestive enzyme treatment.

Clinical Characteristics and Treatment Outcomes of Pathologically Confirmed Aspergillus Nodules

Aspergillus nodules represent a subtype of chronic pulmonary aspergillosis, but details on their characteristics and outcomes are limited. We evaluated 80 patients with pathologically confirmed Aspergillus nodules between January 2009 and December 2016. The median age of the patients was 59 years, and 46 (58%) were women. Seventy-three (91%) patients were surgically diagnosed with Aspergillus nodules and the remaining seven (9%) patients were diagnosed by percutaneous transthoracic needle biopsy. The median long-axis diameter of nodules was 22 mm, and nodules had an internal cavity in 49 (61%) patients. Spiculation and calcification were observed in 20% and 39% of patients, respectively. Ninety percent (18/20) of nodules showed uptake on positron emission tomography. Serum Aspergillus precipitin IgG antibody was positive in 42% (10/24) of tested patients. Seventy-three (91%) patients underwent surgery without (n = 58) or with (n = 15) adjuvant antifungal therapy, and the remaining seven (9%) patients received antifungal therapy alone (n = 5) or no treatment (n = 2). Three patients experienced postoperative pulmonary complications: pneumothorax, hemoptysis, and acute lung injury (n = 1 each). There was no recurrence during the median follow-up period of 36.8 months. In conclusion, surgery could be a treatment strategy worth considering for most Aspergillus nodules. However, given that our study population was heterogeneous, further well-designed studies are need.

Fungal Rhinosinusitis and Disseminated Invasive Aspergillosis in Cats

Fungal rhinosinusitis, including sinonasal aspergillosis (SNA) and sino-orbital aspergillosis (SOA), is the most common type of aspergillosis encountered in cats. Other focal forms of aspergillosis including disseminated invasive aspergillosis occur less frequently. SOA is an invasive mycosis that is increasingly recognized and is most commonly caused by Aspergillus felis, a close relative of Aspergillus fumigatus. SNA can be invasive or noninvasive and is most commonly caused by A fumigatus and Aspergillus niger. Molecular methods are required to correctly identify the fungi that cause SNA and SOA. SNA has a favorable prognosis with treatment, whereas the prognosis for SOA remains poor.

A consensus document for the clinical management of invasive fungal diseases in pediatric patients with hematologic cancer and/or undergoing hematopoietic stem cell transplantation in Brazilian medical centers

In the present paper we summarize the suggestions of a multidisciplinary group including experts in pediatric oncology and infectious diseases who reviewed the medical literature to elaborate a consensus document (CD) for the diagnosis and clinical management of invasive fungal diseases (IFDs) in children with hematologic cancer and those who underwent hematopoietic stem-cell transplantation. All major multicenter studies designed to characterize the epidemiology of IFDs in children with cancer, as well as all randomized clinical trials addressing empirical and targeted antifungal therapy were reviewed. In the absence of randomized clinical trials, the best evidence available to support the recommendations were selected. Algorithms for early diagnosis and best clinical management of IFDs are also presented. This document summarizes practical recommendations that will certainly help pediatricians to best treat their patients suffering of invasive fungal diseases.

Development of a nano-gold immunodiagnostic assay for rapid on-site detection of invasive aspergillosis

Introduction. Timely detection of invasive aspergillosis (IA) caused by fungal pathogens, i.e. Aspergillus fumigatus and Aspergillus flavus, in immunocompromised patients is crucial in preventing high mortality.Aim. To develop a simple immunoassay for the detection of galactomannan (GM), an IA biomarker.Methodology. GM from A. fumigatus and A. flavus clinical strains was purified and characterized by X-ray diffraction, IR spectroscopy and ¹³C/¹H nuclear magnetic resonance (NMR) for polyclonal antibody (pAb) production in rabbits. An enzyme-linked immunosorbent assay (ELISA) was standardized using concanavalin A to capture Aspergillus GM and pAbs to detect it. Gold nanoparticles (AuNPs) were synthesized and conjugated to pAbs for the development of a dot-blot immunoassay. The developed dot-blot was evaluated with 109 clinical serum and bronchoalveolar lavage samples.Results. Spectroscopy studies characterized the d-galactofuranosyl groups of GM responsible for the immune response and generation of pAbs. The ELISA employing pAbs showed a sensitivity of 1 ng ml^-1 for Aspergillus GM. Furthermore, a sensitive, visual, rapid dot-blot assay developed by the conjugation of pAbs to AuNPs (~24±5 nm size, -36±2 mV zeta potential) had a detection limit of 1 pg ml^-1 in serum. The pAbs interacted with Aspergillus spp. but did not cross-react with other fungal pathogen genera such as Penicillium and Candida. Evaluation of the dot-blot with 109 clinical samples showed high sensitivity (80 %) and specificity (93.2 %), with an overall assay accuracy of 89%.Conclusion. The developed nano-gold immunodiagnostic assay has immense potential for practical use in rapid, specific and sensitive on-site diagnosis of IA, even under resource-limited settings.

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.

Hypoxia Decreases Diagnostic Biomarkers for Aspergillosis In Vitro

The aim of the study was to evaluate the influence of hypoxia on galactomannan and (1,3)-β-d-glucan release of clinically relevant Aspergilli in vitro. Hypoxia decreased biomass and consequently led to lower biomarker release. However, when normalized to biomass, hypoxia led to increased levels of biomarkers at early growth stages (24 h). Antifungals (amphotericin B and voriconazole) decreased the galactomannan amount of A. fumigatus, even more prominently in hypoxia.

Absence of cutaneous involvement in disseminated Talaromyces marneffei infection in an AIDS patient: a case report and literature review

Background

Talaromyces marneffei (T. marneffei) is an important opportunistic pathogen found in human immunodeficiency virus-positive individuals in Southeast Asia, Southern China, and Northeastern India. Patients with disseminated talaromycosis commonly develop multi-organ involvement including the skin. In this report, we describe the clinical presentation, investigation, management, and clinical outcome of an acquired immune deficiency syndrome (AIDS) patient with newly diagnosed disseminated talaromycosis without skin involvement.

Case presentation

A 27-year-old male with AIDS presented with acute onset of abdominal pain for 4 days and fever for 2 days. He had been diagnosed with AIDS, pneumocystis pneumonia, and presumptive smear-negative pulmonary tuberculosis 2 months previously. His initial CD4 count was 91 cells/mm³. After a 3-week course of trimethoprim/sulfamethoxazole and anti-tuberculosis treatment, anti-retroviral therapy was initiated. Physical examination revealed left upper quadrant tenderness but no abnormal skin lesions. On this visit, his CD4 count rose to 272 cells/mm³ (19%). Computed tomography of the abdomen showed evidence of a small hypodense lesion with a thin enhancing rim at the spleen and extensive intra-abdominal lymphadenopathy. Empirical amphotericin B deoxycholate was administered in response to positive serum galactomannan, although this was switched to intravenous liposomal amphotericin B 1 week later because of acute kidney injury. Blood and bone marrow cultures for fungus grew T. marneffei on days 9 and 12, respectively. After 21 days of treatment, oral itraconazole replaced intravenous therapy. The patient was discharged home after 29 days in the hospital and continued to improve clinically at a follow-up visit as an outpatient.

Conclusion

Talaromycosis is a fairly common opportunistic infection among AIDS patients in Thailand, despite a rise in CD4 count which may reflect a change in immune status. To a lesser extent, a systemic disease without skin involvement can be expected in real clinical practice.

Galactomannan detection in broncho-alveolar lavage fluid for invasive aspergillosis in immunocompromised patients

BACKGROUND

Invasive aspergillosis (IA) is a life-threatening opportunistic mycosis that occurs in some people with a compromised immune system. The serum galactomannan enzyme-linked immunosorbent assay (ELISA) rapidly gained widespread acceptance as part of the diagnostic work-up of a patient suspected of IA. Due to its non-invasive nature, it can be used as a routine screening test. The ELISA can also be performed on bronchoalveolar lavage (BAL), allowing sampling of the immediate vicinity of the infection. The invasive nature of acquiring BAL, however, changes the role of the galactomannan test significantly, for example by precluding its use as a routine screening test.

OBJECTIVES

To assess the diagnostic accuracy of galactomannan detection in BAL for the diagnosis of IA in people who are immunocompromised, at different cut-off values for test positivity, in accordance with the Cochrane Diagnostic Test Accuracy Handbook.

SEARCH METHODS

We searched three bibliographic databases including MEDLINE on 9 September 2016 for aspergillosis and galactomannan as text words and subject headings where appropriate. We checked reference lists of included studies for additional studies.

SELECTION CRITERIA

We included cohort studies that examined the accuracy of BAL galactomannan for the diagnosis of IA in immunocompromised patients if they used the European Organization for Research and Treatment of Cancer/Invasive Fungal Infections Cooperative Group and the National Institute of Allergy and Infectious Diseases Mycoses Study Group (EORTC/MSG) classification as reference standard.

DATA COLLECTION AND ANALYSIS

Two review authors assessed study quality and extracted data. Quality Assessment of Diagnostic Accuracy Studies-2 (QUADAS-2) was used for quality assessment.

MAIN RESULTS

We included 17 studies in our review. All studies except one had a high risk of bias in two or more domains. The diagnostic performance of an optical density index (ODI) of 0.5 as cut-off value was reported in 12 studies (with 1123 patients). The estimated sensitivity was 0.88 (95% confidence interval (CI) 0.75 to 1.00) and specificity 0.81 (95% CI 0.71 to 0.91). The performance of an ODI of 1.0 as cut-off value could be determined in 11 studies (with 648 patients). The sensitivity was 0.78 (95% CI 0.61 to 0.95) and specificity 0.93 (95% CI 0.87 to 0.98). At a cut-off ODI of 1.5 or higher, the heterogeneity in specificity decreased significantly and was invariably >90%.

AUTHORS' CONCLUSIONS

The optimal cut-off value depends on the local incidence and clinical pathway. At a prevalence of 12% a hypothetical population of 1000 patients will consist of 120 patients with IA. At a cut-off value of 0.5 14 patients with IA will be missed and there will be 167 patients incorrectly diagnosed with IA. If we use the test at a cut-off value of 1.0, we will miss 26 patients with IA. And there will be 62 patients incorrectly diagnosed with invasive aspergillosis. The populations and results were very heterogeneous. Therefore, interpretation and extrapolation of these results has to be performed with caution. A test result of 1.5 ODI or higher appears a strong indicator of IA.

An Autopsy Case with Cerebral Hemorrhaging due to disseminated Aspergillosis During Glucocorticoid Therapy for Overlap Syndrome of Systemic Lupus Erythematosus and Systemic Sclerosis

We encountered a 60-year-old female patient who died of cerebral hemorrhage caused by disseminated aspergillosis during massive steroid therapy for overlap syndrome of systemic lupus erythematosus (SLE) and systemic sclerosis (SSc) and performed autopsy. Histologically, necrotizing vasculitis accompanied by Aspergillus hyphae was noted in the arterial wall of the region with cerebral hemorrhage and an abscess containing Aspergillus clumps was present in the lung, therefor we considered the cerebral hemorrhage caused by disseminated aspergillosis. For immunocompromised patients, it is desirable to perform treatment taking the possibility of deep mycosis into consideration, and when it is suspected, early therapeutic intervention may be useful.

Invasive fungal infections amongst patients with acute-on-chronic liver failure at high risk for fungal infections

AIMS

To study the prevalence, risk factors, role of serum biomarkers for diagnosis and impact of invasive fungal infections (IFIs) in patients with acute-on-chronic liver failure (ACLF).

METHODS

An analysis of IFI in patients with ACLF (EASL criteria) was conducted retrospectively. The diagnosis of IFI in clinically suspected patients was based on EORTC/MSG criteria. The demographical, clinical, laboratory details and outcomes were analysed.

RESULTS

Out of 264 patients with ACLF, 54 (20.4%) patients with suspicion of IFI were evaluated and IFI was diagnosed in 39 (14.7%). Invasive candidiasis was documented in 25 (64.1%) and invasive aspergillosis in 14 (35.8%). The most common source of infection was respiratory (n = 13) followed by renal (n = 7) and spontaneous fungal peritonitis (n = 6). On univariate analysis, diabetes mellitus, hemodialysis, prior antibiotic use, cerebral and respiratory organ failures, Chronic Liver Failure Consortium (CLIF-OF and CLIF-C ACLF) scores were predictors for development of IFI (P < 0.05). On multivariate analysis, hemodialysis and prior antibiotics use predicted the development of IFI (P < 0.05). Non-survivors were more likely to have IFI (P = 0.029), high CLIF-OF and CLIF-C ACLF scores (P < 0.001; for both) and higher 1,3-β D Glucan (BDG) levels (P = 0.009). The sensitivity, specificity, and AUROC of BDG (80 pg/mL) and Galactomannan index (GMI [0.5]) for diagnosing IFI were 97.4%, 60%, 0.770% and 43.6%, 100%, 0.745 respectively.

CONCLUSIONS

Invasive fungal infections constitutes an important cause of mortality in ACLF patients. BDG and GMI can be useful markers to guide antifungal therapy in patients at high risk for IFI.

Reinvestigation of carbohydrate specificity of EB-A2 monoclonal antibody used in the immune detection of Aspergillus fumigatus galactomannan

Great progresses have been made in the recent years in the detection of circulating galactofuranose-bearing molecules for the diagnosis of aspergillosis. However, the test used in the clinical practice is hampered by the occurrence of false positives. A glycoarray with dozens of oligosaccharides structurally related to the Aspergillus fumigatus galactomannan has allowed us to reinvestigate the carbohydrate specificity of the EB-A2 monoclonal antibody used in the Platelia^TM Aspergillus sandwich immune assay. We have now demonstrated that the mAb can recognize shorter oligosaccharides than the previously reported tetrasaccharide Galf-β-(1→5)-Galf-β-(1→5)-Galf-β-(1→5)-Galf-β and oligosaccharides which contains alternating β-(1→5)/β-(1→6)-linkages. This result could explain the occurrence of false-positive signals due to the presence of the abovementioned epitopes not only in A. fumigatus galactomannan but also in other bacteria and fungi.

New Concepts in Diagnostics for Invasive Mycoses: Non-Culture-Based Methodologies

Non-culture-based diagnostics have been developed to help establish an early diagnosis of invasive fungal infection. Studies have shown that these tests can significantly impact the diagnosis of infection in high risk patients. Aspergillus galactomannan EIA testing is well-recognized as an important adjunct to the diagnosis of invasive aspergillosis and can be detected in serum, bronchoalveolar lavage and other fluids. Galactomannan testing used along with PCR testing has been shown to be effective when integrated into care paths for high risk patients for both diagnoses and as a surrogate marker for outcome when used in serial testing. Beta-d-glucan assays are non-specific for several fungal genera including Aspergillus and Candida and in high risk patients have been an important tool to augment the diagnosis. Lateral flow technology using monoclonal antibodies to Aspergillus are available that allow rapid testing of clinical samples. While standard PCR for Candida remains investigational, T2 magnetic resonance allows for the rapid diagnosis of Candida species from blood cultures. Aspergillus PCR has been extensively validated with standardized approaches established for these methods and will be included in the diagnostic criteria in the revised European Organization for Research and Treatment of Cancer/Mycoses Study Group (EORTC-MSG) definitions. Finally, these non-culture-based tests can be used in combination to significantly increase the detection of invasive mycoses with the ultimate aim of establishing an early diagnosis of infection.

Current State of the Diagnosis of Invasive Pulmonary Aspergillosis in Lung Transplantation

As the number of lung transplants performed worldwide each year continues to grow, the success of this procedure is threatened by the incidence of non-CMV infections such as invasive aspergillosis. Despite tremendous efforts and the availability of numerous diagnostic tests (especially in hematological malignancies) the diagnosis of invasive aspergillosis continues to be a challenge. Lung transplantation remains a unique clinical scenario, where additional host defenses are immunocompromized, making many of the available tests unsuitable. In this review we will navigate through the myriad of diagnostic tests currently available and how they apply to this unique patient population, as well as have a look into what the future holds.

Development of a Fluorescently Labeled Aptamer Structure-Switching Assay for Sensitive and Rapid Detection of Gliotoxin

Gliotoxin, one of the most toxic metabolites produced during the growth of Aspergillus fumigatus, can cause direct damage to the immune system and results in infection and spread of Aspergillus, or even leads to invasive aspergillosis. Accurate, rapid, and sensitive detection of the disease-specific marker gliotoxin, particularly in serum, urine, or other body fluids, is therefore an important approach to achieving early and rapid diagnosis of Invasive Aspergillus Fumigatus Infection (IAFI). In this study, aptamers that specifically bind to gliotoxin were successfully obtained using immobilization-free GO-SELEX technology. Furthermore, the performance of the aptamer, including binding affinity, targeting specificity, and structural stability, was further improved by optimizing through truncation and mutation. Finally, the optimized aptamer APT8T1M was used to develop a novel fluorescently labeled aptamer structure-switching assay (FLASSA) for the detection of gliotoxin. The method exhibited a good linear range from 0.1 nM to 100 nM of gliotoxin, with a lower detection limit of 0.05 nM. Moreover, FLASSA was applied to the detection of gliotoxin in spiked serum and urine samples. A good mean recovery of 98.76-110.85% and a low coefficient of variation (5.45-14.59%) were obtained, indicating a high degree of selectivity for gliotoxin, good reproducibility, and stability. These results show that the developed FLASSA has significant potential and offers an alternative to the traditional analytical methods for the rapid, sensitive, and efficient detection of gliotoxin, thus, providing an effective tool for the early and rapid diagnosis of IAFI.

Treating invasive aspergillosis in patients with hematologic malignancy: diagnostic-driven approach versus empiric therapies

BACKGROUND

Early antifungal therapy for invasive aspergillosis (IA) has been associated with improved outcome. Traditionally, of empiric antifungal therapy has been used for clinically suspected IA. We compared outcomes of patients with hematologic malignancy and IA who were treated with voriconazole using the diagnostic driven DDA (DDA-Vori) that includes galactomannan testing vs. empiric therapy with a non-voriconazole-containing regimen (EMP-non-Vori) or empiric therapy with voriconazole (EMP-Vori).

METHODS

We retrospectively reviewed the medical records of 342 hematologic malignancy patients diagnosed with proven, or probable IA between July 1993 and February 2016 at our medical center who received at least 7 days of DDA-Vori, EMP-Vori, or EMP-non-Vori. Outcome assessment included response to therapy (clinical and radiographic), all-cause mortality, and IA-attributable mortality.

RESULTS

By multivariate analysis, factors predictive of a favorable response included localized/sinus IA vs. disseminated/pulmonary IA (p <  0.0001), not receiving white blood cell transfusion (p <  0.01), and DDA-Vori vs. EMP-non-Vori (p < 0.0001). In contrast, predictors of mortality within 6 weeks of initiating IA therapy included disseminated/pulmonary infection vs. localized/sinus IA (p < 0.01), not undergoing stem cell transplantation within 1 year before IA (p = 0.01), and EMP-non-Vori vs. DDA-Vori (p < 0.001).

CONCLUSIONS

DDA-Vori was associated with better outcome (response and survival) compared with EMP-non-Vori and with equivalent outcome to EMP-Vori in hematologic malignancy patients. These outcomes associated with the implementation of DDA could lead to a reduction in the unnecessary costs and adverse events associated with the widespread use of empiric therapy.

False positive bronchoalveolar lavage galactomannan: Effect of host and cut-off value

OBJECTIVES

Bronchoalveolar lavage galactomannan (BAL-GM) is a mycological criterion for diagnosis of probable invasive aspergillosis (IA) per European Organization for Research and Treatment of Cancer/Mycoses Study Group (EORT-MSG) consensus criteria, but its real-world positive predictive value (PPV) has not been well-studied. Our aim was to estimate the PPV of BAL-GM in a contemporary cohort of patients with positive BAL-GM.

METHODS

We identified consecutive patients with ≥1 positive BAL-GM value (index ≥ 0.5) at Brigham and Women's Hospital from 11/2009 to 3/2016. We classified patients as having no, possible, probable, or proven IA, excluding BAL-GM as mycological criterion.

RESULTS

We studied 134 patients: 54% had hematologic malignancy (HM), and 10% were solid organ transplant (SOT) recipients. A total of 42% of positive (≥0.5) BAL-GM results were falsely positive (PPV 58%). The number of probable IA cases was increased by 23% using positive BAL-GM as mycologic criterion alone. PPV was higher in patients with HM or SOT (P < 0.001) and with use of higher thresholds for positivity (BAL-GM ≥ 1 vs 1-0.8 vs 0.8-0.5: P = 0.002).

CONCLUSIONS

42% of positive BAL-GM values were falsely positive. We propose a critical reassessment of BAL-GM cutoff values in different patient populations. Accurate noninvasive tests for diagnosis of IA are urgently needed.

Genotyping of Aspergillus fumigatus in Formalin-Fixed Paraffin-Embedded Tissues and Serum Samples From Patients With Invasive Aspergillosis

Invasive aspergillosis (IA) is a deep tissue infection with a high mortality occurring mostly in immunocompromised patients. To investigate the pathology of patients with IA it may be important to determine the genotype of the invasive isolate of Aspergillus, however available tissues for study are often formalin fixed paraffin embedded (FFPE). Although DNA has been successfully isolated from such tissues for species identification, genotyping of Aspergillus species on such tissues has not yet been performed. In this study we aimed to determine the genotype of Aspergillus fumigatus in FFPE tissue and serum samples from five patients with invasive aspergillosis using nine highly polymorphic short tandem repeat (STRAf) loci. FFPE lung and bronchial biopsies from all patients were successfully typed. By comparing the latter result with non-FFPE materials from non-sterile samples such as sputum, bronchoalveolar lavage and lung abscess, we found identical genotypes within three patients, while the two other patients had a dominant genotype shared among all sample types. Genotyping of serum samples was successful in two serum samples with galactomannan ratios of 4 and 5.6, but failed in serum samples with galactomannan levels <0.5. In addition, testing a subset of these materials with the AsperGenius multiplex qPCR assay, we did not find azole resistance mutations. With this STRAf assay, A. fumigatus from FFPE tissue and serum was successfully genotyped, allowing retrospective examination of A. fumigatus in culture negative patients with IA.