Autopsy-controlled prospective evaluation of serial screening for circulating galactomannan by a sandwich enzyme-linked immunosorbent assay for hematological patients at risk for invasive Aspergillosis

Invasive Fungal Infections in Inpatient Solid Organ Transplant Recipients With COVID-19: A Multicenter Retrospective Cohort

BACKGROUND

The prevalence and outcomes of COVID-19-associated invasive fungal infections (CAIFIs) in solid organ transplant recipients (SOTRs) remain poorly understood.

METHODS

A retrospective cohort study of SOTRs with COVID-19 admitted to 5 hospitals within Johns Hopkins Medicine was performed between March 2020 and March 2022. Cox regression multilevel mixed-effects ordinal logistic regression was used.

RESULTS

In the cohort of 276 SOTRs, 22 (8%) developed IFIs. The prevalence of CAIFIs was highest in lung transplant recipients (20%), followed by recipients of heart (2/28; 7.1%), liver (3/46; 6.5%), and kidney (7/149; 4.7%) transplants. In the overall cohort, only 42 of 276 SOTRs (15.2%) required mechanical ventilation; these included 11 of 22 SOTRs (50%) of the CAIFI group and 31 of 254 SOTRs (12.2%) of the no-CAIFI group. Compared with those without IFIs, SOTs with IFIs had worse outcomes and required more advanced life support (high-flow oxygen, vasopressor, and dialysis). SOTRs with CAIFIs had higher 1-y death-censored allograft failure (hazard ratio 1.6 5.1 16.4 , P  = 0.006) and 1-y mortality adjusting for oxygen requirement (adjusted hazard ratio 1.1 2.4 5.1 , P  < 0.001), compared with SOTRs without CAIFIs.

CONCLUSIONS

The prevalence of CAIFIs in inpatient SOTRs with COVID-19 is substantial. Clinicians should be alert to the possibility of CAIFIs in SOTRs with COVID-19, particularly those requiring supplemental oxygen, regardless of their intubation status.

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.

Diagnosis and Antifungal Prophylaxis for COVID-19 Associated Pulmonary Aspergillosis

The COVID-19 pandemic has redemonstrated the importance of the fungal-after-viral phenomenon, and the question of whether prophylaxis should be used to prevent COVID-19-associated pulmonary aspergillosis (CAPA). A distinct pathophysiology from invasive pulmonary aspergillosis (IPA), CAPA has an incidence that ranges from 5% to 30%, with significant mortality. The aim of this work was to describe the current diagnostic landscape of CAPA and review the existing literature on antifungal prophylaxis. A variety of definitions for CAPA have been described in the literature and the performance of the diagnostic tests for CAPA is limited, making diagnosis a challenge. There are only six studies that have investigated antifungal prophylaxis for CAPA. The two studied drugs have been posaconazole, either a liquid formulation via an oral gastric tube or an intravenous formulation, and inhaled amphotericin. While some studies have revealed promising results, they are limited by small sample sizes and bias inherent to retrospective studies. Additionally, as the COVID-19 pandemic changes and we see fewer intubated and critically ill patients, it will be more important to recognize these fungal-after-viral complications among non-critically ill, immunocompromised patients. Randomized controlled trials are needed to better understand the role of antifungal prophylaxis.

Fungal infections diagnosis - Past, present and future

Despite the scientific advances observed in the recent decades and the emergence of new methodologies, the diagnosis of systemic fungal infections persists as a problematic issue. Fungal cultivation, the standard method that allows a proven diagnosis, has numerous disadvantages, as low sensitivity (only 50% of the patients present positive fungal cultures), and long growth time. These are factors that delay the patient's treatment and, consequently, lead to higher hospital costs. To improve the accuracy and quickness of fungal infections diagnosis, several new methodologies attempt to be implemented in clinical microbiology laboratories. Most of these innovative methods are independent of pathogen isolation, which means that the diagnosis goes from being considered proven to probable. In spite of the advantage of being culture-independent, the majority of the methods lack standardization. PCR-based methods are becoming more and more commonly used, which has earned them an important place in hospital laboratories. This can be perceived now, as PCR-based methodologies have proved to be an essential tool fighting against the COVID-19 pandemic. This review aims to go through the main steps of the diagnosis for systemic fungal infection, from diagnostic classifications, through methodologies considered as "gold standard", to the molecular methods currently used, and finally mentioning some of the more futuristic approaches.

Two Monoclonal Antibodies That Specifically Recognize Aspergillus Cell Wall Antigens and Can Detect Circulating Antigens in Infected Mice

Invasive aspergillosis (IA) is a life-threatening disease mainly caused by Aspergillus fumigatus and Aspergillus flavus. Early diagnosis of this condition is crucial for patient treatment and survival. As current diagnostic techniques for IA lack sufficient accuracy, we have raised two monoclonal antibodies (1D2 and 4E4) against A. fumigatus cell wall fragments that may provide a platform for a new diagnostic approach. The immunoreactivity of these antibodies was tested by immunofluorescence and ELISA against various Aspergillus and Candida species in vitro and by immunohistochemistry in A. fumigatus infected mouse tissues. Both monoclonal antibodies (mAbs) showed intensive fluorescence with the hyphae wall of A. fumigatus and A. flavus, but there was no staining with other Aspergillus species or Candida species. Both mAbs also showed strong immunoreactivity to the cell wall of A. fumigatus hyphae in the infected liver, spleen and kidney of mice with IA. The antigens identified by 1D2 and 4E4 might be glycoproteins and the epitopes are most likely a protein or peptide rather than a carbohydrate. An antibody-based antigen capture ELISA detected the extracellular antigens released by A. fumigatus, A. flavus, A. niger and A. terreus, but not in Candida species. The antigen could be detected in the plasma of mice after 48 h of infection by double-sandwich ELISA. In conclusion, both 1D2 and 4E4 mAbs are potentially promising diagnostic tools to investigate invasive aspergillosis.

Utility of Panfungal PCR in the diagnosis of invasive fungal infections in febrile neutropenia

Background:

The prevalence of invasive fungal infections (IFIs) is increasing due to the increasing population of immunocompromised patients. Fungal culture is the gold standard for diagnosis but not sensitive and the turnaround time is long. Samples for histopathology are difficult to obtain because of profound cytopenias. We conducted this study with the aim to evaluate panfungal PCR for the diagnosis of IFIs in patients of febrile neutropenia.

Methods:

This was a single-centre, cross-sectional observational study. Patients of febrile neutropenia suspected of having IFI were included in the study. Panfungal PCR was performed on the blood of included patients along with other investigations for diagnosis of IFI. The sensitivity, specificity, positive predictive value, and negative predictive value of panfungal PCR were calculated using EORTC/MSG 2008 criteria as the gold standard.

Results:

Fifty patients of febrile neutropenia were included in the study, of which 52% were diagnosed positive by panfungal PCR assay. The sensitivity, specificity, positive predictive value, and negative predictive value of panfungal PCR assay was found to be 82.76%, 90.48%, 92.31% and 79.17% respectively.

Conclusion:

Panfungal PCR is a promising and highly sensitive diagnostic test for screening at-risk patients suspected to have IFIs. The use of panfungal PCR assay in combination with other diagnostic modalities and clinical judgment can be very helpful in the early diagnosis of IFI.

Role of Nasal Lavage Fluid Galactomannan Levels For Diagnosis of Invasive Aspergillosis in Patients with Leukemia

Background: Invasive aspergillosis (IA) is the most prevalent invasive infection with high mortality among patients with leukemia. Early diagnosis of IA has been a challenging topic in this group of patients. Objectives: In this study, we evaluated the galactomannan levels of nasal lavage fluid (NALF) as a possible auxiliary method for IA diagnosis in patients with leukemia. Methods: In a prospective study, 32 adult patients with leukemia who were taking induction and/or consolidation chemotherapy with fever and neutropenia were included. In all patients, galactomannan (GM) levels of serum and NALF, and mycological examinations were evaluated before the first dose of antifungal therapy. Results: Fourteen (43.7%) patients had NALF GM ≥ 0.5; however, in 16 (50%) patients the level of serum GM was ≥ 0.5. The elevated level of NALF GM had a significant association with the proven IA cases (P = 0.048). The GM level of NALF with a cut-off value of 0.45 (by receiver operating characteristic curve analysis) had 78% sensitivity and 64% specificity for the diagnosis of invasive aspergillosis (P = 0.033). Conclusions: Due to its non-invasive nature, GM level of NALF may be contributory to be used as part of the diagnostic work‐up of IA particularly in leukemic patients with thrombocytopenia which prohibits acquiring bronchoalveolar lavage.

Comparison of β-D-Glucan and Galactomannan in Serum for Detection of Invasive Aspergillosis: Retrospective Analysis with Focus on Early Diagnosis

The early diagnosis of invasive aspergillosis (IA) relies mainly on computed tomography imaging and testing for fungal biomarkers such as galactomannan (GM). We compared an established ELISA for the detection of GM with a turbidimetric assay for detection of the panfungal biomarker β-D-glucan (BDG) for early diagnosis of IA. A total of 226 serum specimens from 47 proven and seven probable IA cases were analysed. Sensitivity was calculated for samples obtained closest to the day of IA-diagnosis (d0). Additional analyses were performed by including samples obtained during the presumed course of disease. Most IA cases involved the respiratory system (63%), and Aspergillus fumigatus was the most frequently isolated species (59%). For proven cases, sensitivity of BDG/GM analysis was 57%/40%. Including all samples dating from –6 to +1 weeks from d0 increased sensitivities to 74%/51%. Sensitivity of BDG testing was as high as or higher than GM testing for all subgroups and time intervals analysed. BDG testing was less specific (90–93%) than GM testing (99–100%). Combining BDG and GM testing resulted in sensitivity/specificity of 70%/91%. Often, BDG testing was positive before GM testing. Our study backs the use of BDG for diagnosis of suspected IA. We suggest combining BDG and GM to improve the overall sensitivity.

Study on invasive aspergillosis using galactomannan enzyme immunoassay and determining antifungal drug susceptibility among hospitalized patients with hematologic malignancies or candidates for organ transplantation

The incidence of invasive aspergillosis (IA) has dramatically increased during the last decade. This infection is associated with high morbidity and mortality, ranging from 30% to 70%, especially in immunocompromised patients. Delay in diagnosis and treatment is usually associated with high mortality rates. This study was aimed to assess the diagnostic value of Galactomannan EIA (GM) for early diagnosis of aspergillosis in hospitalized patients with underlying conditions. Also, the antifungal drug susceptibility profiles of causative agents were investigated. In this descriptive cross-sectional study, during the period of 18 months starting from September 2017 until February 2019, 22 bronchoalveolar lavage (BAL) and 13 biopsies from infected sinuses were obtained from a total of 150 patients suffering from different types of hematologic malignancies. All the samples were subjected to microscopic examination and fungal culture. Also, serum specimens were obtained from all patients (n = 135). 22 serum and 17 BAL specimens were tested for the GM level. Fungal identified were confirmed through the PCR-sequencing of the β-tubulin gene. The susceptibility to amphotericin B, itraconazole, voriconazole, posaconazole, ravuconazole, and caspofungin was evaluated according to the Clinical and Laboratory Standards Institute document M38-A2 (CLSI M38-A2) broth microdilution protocol. The results showed that the incident rate of IA was 23.33% and 35 patients with IA (12 proven cases and 23 probable cases) were diagnosed according to the European Organization for Research and Treatment of Cancer and Mycoses Study Group criteria. The 35 patients with IA in the current study comprised 19 men (54.29%) and 16 women (45.71%) with the median age of 42 years. AML (31.5%) was documented as the most prevalent risk factor among our subjects with IA and Aspergillus flavus (65.7%) was the most prevailing causal agent in this study. Among patients with IA, ague (71%) and cough (60%) were the most common symptoms. In the present study, a sensitivity of 94% and a specificity of 98% was reported for GM ELISA in BAL specimens. Also, a sensitivity of 58% and a specificity of 98% was reported for GM ELISA in serum samples. Among 6 tested antifungal drugs, the lowest minimum inhibitory concentration (MIC) values were observed for posaconazole and ravuconazole which showed the range of 0.008-0.0062 μgml and 0.031-0.125 μgml, respectively. The current study has demonstrated that determining the value of GM investigation in BAL and serum specimens can be promising in early diagnosis of IA, also molecular identification of the agents causing IA and their antifungal susceptibility patterns are essential issues for the targeted antifungal therapy and outcome improvement of patients with this life-threatening disease.

Invasive Pulmonary Aspergillosis in Chronic Obstructive Pulmonary Disease Exacerbations

Nowadays, reports in the literature support that patients with severe chronic obstructive pulmonary disease (COPD) are at higher risk to develop invasive pulmonary aspergillosis (IPA). However, the interpretation of Aspergillus-positive cultures from the airways in critically ill COPD is still a challenge. Indeed, as the patient could be merely colonized, tissue samples are required to ascertain IPA diagnosis but they are rarely obtained before death. Consequently, diagnosis is often only suspected on the basis of a combination of three elements: clinical characteristics, radiological images (mostly thoracic CT scan), and microbiological, and occasionally serological, results. To facilitate the analysis of these data, several algorithms have been developed, and the best effectiveness has been demonstrated by the Clinical algorithm. This is of importance as IPA prognosis in these patients remains presently very poor and using such an algorithm could promote prompter diagnosis, early initiation of treatment, and subsequently improved outcome.While the most classical presentation of IPA in critically ill COPD patients features a combination of obstructive respiratory failure, antibiotic-resistant pneumonia, recent or chronic corticosteroid therapy, and positive Aspergillus cultures from the lower respiratory tract, the present article will also address less typical presentations and discuss the most appropriate treatments which could alter prognosis.

Enhanced paper-based ELISA for simultaneous EVs/exosome isolation and detection using streptavidin agarose-based immobilization

EVs/exosomes are considered as the next generation of biomarkers, including for liquid biopsies. Consequently, the quantification of EVs/exosomes is crucial for facilitating EV/exosome research and applications. Paper-based enzyme-linked immunosorbent assay (p-ELISA) is a portable diagnostic system with low cost that is simple and easy to use; however, it shows low sensitivity and linearity. In this study, we develop p-ELISA for targeting EVs/exosomes by using streptavidin agarose resin-based immobilization (SARBI). This method reduces assay preparation times, provides strong binding, and retains good sensitivity and linearity. The time required for the total assay, including preparation steps and surface immobilization, was shortened to ∼2 h. We evaluated SARBI p-ELISA systems with/without CD63 capture Ab and then with fetal bovine serum (FBS) and EVs/exosome-depleted fetal bovine serum (dFBS). The results provide evidence supporting the selective capture ability of SARBI p-ELISA. We obtain semiquantitative p-ELISA results using an exosome standard (ES) and human serum (HS), with R2 values of 0.95 and 0.92, respectively.

Strategies for the management of invasive fungal infections due to filamentous fungi in high-risk hemato-oncological patients

OBJECTIVE

In recent years, the introduction of new antifungals for the prevention of invasive fungal infections (IFIs) in hemato- oncological patients, particularly extended-spectrum azoles, has led to a change in the diagnostic and therapeutic strategies for established or suspected breakthrough IFI. The aim of the study was to identify the diagnostic and therapeutic strategies used in the management of IFIs in hemato-oncological patients in Spain, and to assess compliance with the recommendations of the consensus documents and clinical practice guidelines.

METHODS

An online, anonymous, cross-sectional survey was conducted between January and September 2016 involving 137 specialists from third-level hospitals in Spain with Departments of Hematology that regularly deal with IFIs.

RESULTS

Galactomannan test was available to 95.6% of specialists, and was used in 61.7% of the cases for diagnostic confirmation and early treatment. The (1 → 3) β-D-glucan test was only available to 10.2%. A total of 75.3% of the participants estimated the incidence of breakthrough IFI due to filamentous fungus as being 1-10%. In turn, 83.3% of the participants decided a change in antifungal class after failure of prophylaxis, in concordance with the recommendations of the national and international consensus documents.

CONCLUSIONS

The present study, the first of its kind conducted in Spain, shows that a high percentage of the medical professionals implicated in the management of hemato-oncological patients at high risk of suffering IFIs follow the recommendations of the national and international consensus documents and guidelines.

Diagnosis of invasive fungal diseases in haematology and oncology: 2018 update of the recommendations of the infectious diseases working party of the German society for hematology and medical oncology (AGIHO)

Invasive fungal diseases (IFD) are a primary cause of morbidity and mortality in patients with haematological malignancies. These infections are mostly life-threatening and an early diagnosis and initiation of appropriate antifungal therapy are essential for the clinical outcome. Most commonly, Aspergillus and Candida species are involved. However, other Non-Aspergillus moulds are increasingly identified in case of documented IFD. For definite diagnosis of IFD, a combination of diagnostic tools have to be applied, including conventional mycological culture and non-conventional microbiological tests such as antibody/antigen and molecular tests, as well as histopathology and radiology. Although varying widely in cancer patients, the risk of invasive fungal infection is highest in those with allogeneic stem cell transplantation and those with acute leukaemia and markedly lower in patients with solid cancer. Since the last edition of Diagnosis of Invasive Fungal Diseases recommendations of the German Society for Hematology and Oncology in 2012, integrated care pathways have been proposed for the management and therapy of IFDs with either a diagnostic driven strategy as opposed to a clinical or empirical driven strategy. This update discusses the impact of this additional evidence and effective revisions.

Diagnosis of invasive mold diseases in patients with hematological malignancies using Aspergillus, Mucorales, and panfungal PCR in BAL

BACKGROUND

Accurate diagnosis of invasive mold diseases (IMD) remains challenging. Here, the performance of panfungal PCR, Aspergillus and MucoralesPCR in bronchoalveolar lavage (BAL) was evaluated.

METHODS

We conducted a single-center study including 167 hematologic patients at risk for IMD with BAL performed 2011-2014. Diagnostic performance of single tests (Aspergillus-, Mucorales-, and panfungal PCR, galactomannan (GM)≥0.5 and ≥1, culture/cytology) or in combination was calculated for predicting IMD comparing proven/probable or proven/probable/possible IMD vs no IMD, respectively.

RESULTS

IMD was classified as proven (n = 6), probable (n = 31), possible (n = 29) and no IMD (n = 101) according to EORTC/MSG criteria. GM ≥ 0.5 in BAL showed the highest sensitivity with 81% for diagnosing IMD whereas the other tests only 5%-35%. By contrast, specificity was highest for panfungal PCR with 99% and GM ≥ 1, Mucorales and AspergillusPCR reached specificity ≥91%. When combining the tests, GM ≥ 0.5 and panfungal PCR show a sensitivity and specificity of 87% and 78% for IMD or with AspergillusPCR a sensitivity and specificity of 88% and 72% for invasive pulmonary aspergillosis, respectively. Including possible IMD patients did not improve the sensitivity of PCRs. In probable/proven IMD patients, the addition of panfungal PCR resulted further in detection of Fusarium species and Alternaria species, and the MucoralesPCR was positive in 2 probable IMD cases.

CONCLUSION

This study illustrates that the diagnosis of IMD is still very problematic and lacks objectivity. Together with GM in BAL, the PCRs may prove an addition to the current available diagnostic armamentarium in IMD because of their ability to identify molds on a species level.

Production of the Invasive Aspergillosis Biomarker Bis(methylthio)gliotoxin Within the Genus Aspergillus: In Vitro and in Vivo Metabolite Quantification and Genomic Analysis

Gliotoxin (GT) is a fungal secondary metabolite that has attracted great interest due to its high biological activity since it was discovered by the 1930s. An inactive derivative of this molecule, bis(methylthio)gliotoxin (bmGT), has been proposed as an invasive aspergillosis (IA) biomarker. Nevertheless, studies regarding bmGT production among common opportunistic fungi, including the Aspergillus genus, are scarce and sometimes discordant. As previously reported, bmGT is produced from GT by a methyl-transferase, named as GtmA, as a negative feedback regulatory system of GT production. In order to analyze the potential of bmGT detection to enable identification of infections caused by different members of the Aspergillus genus we have assessed bmGT production within the genus Aspergillus, including A, fumigatus, A. niger, A. nidulans, and A. flavus, and its correlation with gtmA presence. In order to validate the relevance of our in vitro findings, we compared bmGT during in vitro culture with the presence of bmGT in sera of patients from whom the Aspergillus spp. were isolated. Our results indicate that most A. fumigatus isolates produce GT and bmGT both in vitro and in vivo. In contrast, A. niger and A. nidulans were not able to produce GT or bmGT, although A. niger produced bmGT from a exogenous GT source. The frequency and amount of bmGT production in A. terreus and A. flavus isolates in vitro was lower than in A. fumigatus. Our results suggest that this defect could be related to the in vitro culture conditions, since isolates that did not produce bmGT in vitro were able to synthetize it in vivo. In summary, our study indicates that bmGT could be very useful to specifically detect the presence of A. fumigatus, the most prevalent agent causing IA. Concerning A. terreus and A. flavus a higher number of analyses from sera from infected patients will be required to reach a useful conclusion.

Diagnostic Approaches for Invasive Aspergillosis-Specific Considerations in the Pediatric Population

Invasive aspergillosis (IA) is a major cause of morbidity and mortality in children with hematological malignancies and those undergoing hematopoietic stem cell transplantation. Similar to immunocompromised adults, clinical signs, and symptoms of IA are unspecific in the pediatric patient population. As early diagnosis and prompt treatment of IA is associated with better outcome, imaging and non-invasive antigen-based such as galactomannan or ß-D-glucan and molecular biomarkers in peripheral blood may facilitate institution and choice of antifungal compounds and guide duration of therapy. In patients in whom imaging studies suggest IA or another mold infection, invasive diagnostics such as bronchoalveolar lavage and/or bioptic procedures should be considered. Here we review the current data of diagnostic approaches for IA in the pediatric setting and highlight the major differences of performance and clinical utility of the tests between children and adults.

Evaluation of serum galactomannan enzyme immunoassay at two different cut-offs for the diagnosis of invasive aspergillosis in patients with febrile neutropenia

BACKGROUND

Invasive aspergillosis (IA) is an increasingly common and fatal opportunistic fungal infection in patients with haematological diseases. Early diagnosis is difficult as mycological culture techniques have low sensitivity and the radiological tools have low specificity. Galactomannan enzyme immunoassay (GEI) detects galactomannan in the human serum with a reported sensitivity and specificity between 30% and 100%.

AIMS

The aim of this study was to analyse the role of GEI in diagnosis of IA in patients with febrile neutropenia and to evaluate the role of GEI in the diagnosis of IA as per the revised (2008) European Organization for Research and Treatment of Cancer-Mycoses Study Group (EORTC-MSG) criteria at two different optical density (OD) cut-offs of 0.5 and 1.0.

SETTING

This prospective study was conducted in Safdarjung Hospital, New Delhi, India.

METHODS

GEI testing was performed in adult patients of febrile neutropenia with evidence of IA. Results at two different OD indices (ODIs) of 0.5 and 1.0 were analysed. The evaluation of the diagnostic parameter, that is, GEI was measured in terms of sensitivity, specificity and positive and negative predictive value and was validated with the revised (2008) EORTC-MSG diagnostic criteria of IA.

RESULTS

One hundred and eleven patients had evidence of IA, of which 79 patients were GEI positive when cut-off ODI was 0.5, whereas with cut-off ODI 1.0, 55 patients were GEI positive.

CONCLUSION

ODI of 1.0 should be considered as positive while in patients with OD between 0.5 and 1.0, repeat sampling from the patient is recommended.

Translational Development and Application of (1→3)-β-d-Glucan for Diagnosis and Therapeutic Monitoring of Invasive Mycoses

Early diagnosis and prompt initiation of appropriate antimicrobial therapy are crucial steps in the management of patients with invasive fungal infections. However, the diagnosis of invasive mycoses remains a major challenge in clinical practice, because presenting symptoms may be subtle and non-invasive diagnostic assays often lack sensitivity and specificity. Diagnosis is often expressed on a scale of probability (proven, probable and possible) based on a constellation of imaging findings, microbiological tools and histopathology, as there is no stand-alone assay for diagnosis. Recent data suggest that the carbohydrate biomarker (1→3)-β-d-glucan may be useful in both the diagnosis and therapeutic monitoring of invasive fungal infections due to some yeasts, molds, and dimorphic fungi. In this paper, we review recent advances in the use of (1→3)-β-d-glucan to monitor clinical response to antifungal therapy and explore how this assay may be used in the future.

A Review of Diagnostic Methods for Invasive Fungal Diseases: Challenges and Perspectives

Invasive fungal diseases are associated with a high morbidity and mortality, particularly in the context of immunosuppression. Diagnosis of invasive fungal diseases is usually complicated by factors such as poor clinical suspicion and unspecific clinical findings. Access to modern diagnostic tools is frequently limited in developing countries. Here, we describe five real-life clinical cases from a Brazilian tertiary hospital, in order to illustrate how to best select diagnostic tests in patients with different fungal infections.

Current Algorithms in Fungal Diagnosis in the Immunocompromised Host

Invasive fungal diseases (IFDs) are a major cause of morbidity and mortality in immunocompromised patients such as patients with hematological malignancies or allogeneic hematopoietic stem cell transplant recipients. Whereas the definite diagnosis of IFD requires invasive diagnostic procedures, imaging and noninvasive diagnostic assays may help in decision making with regard to the institution and the choice of antifungal agents, the duration of therapy, surgical intervention, and monitoring of fungal manifestations.Unfortunately, signs and symptoms of IFD are often nonspecific in the immunocompromised patient. Therefore, in immunocompromised patients with suspected IFD, all samples collected need to be cultured for fungi, and, in the case of specimens obtained by invasive diagnostic procedures, also microscopically examined. For high sensitivity of the cultural and microscopic approaches, specific media and stains, respectively, are crucial. Non-culture based method such as the detection of galactomannan or ß-d-glucan and molecular tools such as polymerase chain reaction may help in the early diagnosis of IFD. Imaging studies may be indicative for IFD, but invasive diagnostics such as bronchoalveolar lavage and/or biopsy should be pursued in order to identify the causative pathogen. This chapter summarizes the current knowledge on diagnosing IFD and proposes practical help in the use of diagnostic tools.

Comparison of 1,3-β-d-glucan with galactomannan in serum and bronchoalveolar fluid for the detection of Aspergillus species in immunosuppressed mechanical ventilated critically ill patients

PURPOSE

Invasive pulmonary aspergillosis (IPA) is an important cause of morbidity/mortality in immunocompromised critically ill patients. New diagnostic strategies for early detection of IPA include the noninvasive biomarkers 1,3-β-d-glucan (BDG), serum, and bronchoalveolar (BAL) fluid galactomannan (GM). The aim of this study was to compare these markers for early detection of IPA in immunosuppressed critically ill patients.

METHODS

Between December 2014 and December 2015, 49 immunosuppressed patients with respiratory failure were treated at our intensive care unit (ICU). We compared the BDG Fungitell assay with GM Platelia assay in serum and BAL for early detection of IPA. All tests were performed initially after admission at the ICU.

RESULTS

In our study with 49 patients, 13 (26%) had probable IPA. These patients had a higher Acute Physiology And Chronic Health Evaluation II score (28 vs 23, P<.001), Sequential Organ Failure Assessment score (16 vs 14, P<.001), more neutropenia (77% vs 30%, P<.001), worse Horowitz Index (99 vs 73 P<.020), a longer ICU stay (26 vs 17 days, P<.044), and a higher mortality rate (77% vs 58%, P<.001) as compared with patients without probable IPA. The used biomarker BDG presented in patients with probable IPA showed significantly higher levels as compared with patients without probable IPA (375 [103-1000 pg/mL; P<.001] vs 64 [30-105 pg/mL; P < .001]). Comparison of BDG with GM showed that positive serum GM could be detected in only 4 (30%), whereas positive BAL GM could be detected in 12 (92%; mean optical density index, 3.7) of 13 probable IPA cases. These results can be expressed as an overall sensitivity of 88% and a specificity of 82% for probable IPA using the BDG Fungitell assay, a sensitivity of 35% and a specificity of 70% using the serum GM Platelia assay, and a sensitivity of 70% and a specificity of 94% using the BAL GM Platelia assay. The negative predictive values of the used tests were 94% for the BDG Fungitell assay, 94% for the serum GM Platelia assay, and 90% for the BAL GM Platelia assay.

CONCLUSION

1,3-β-d-Glucan may be a useful marker for patients under surveillance at risk for IPA. In critically ill patients with immunosuppression, early diagnosis of IPA may be improved by BDG as compared with serum GM. However, diagnostic performance and accuracy increase when BDG is run in parallel with GM from BAL; moreover, the association of the 2 parameters has also the advantage of detecting early and reliable IPA.

Analysis of peritoneal galactomannan for the diagnosis of Aspergillus peritonitis

Here, we report a patient developing a postoperative peritoneal infection by Aspergillus fumigatus. While galactomannan serum levels were negative throughout the time course, galactomannan levels in peritoneal fluids yielded high results. Serological testing of peritoneal fluids for fungal antigens might be a useful and easily applicable tool to support diagnosis of intraabdominal aspergillosis, which represents a rare type of invasive fungal infection.

Comparison of Serum Galactomannan and 1,3-Beta-D-Glucan Determination for Early Detection of Invasive Pulmonary Aspergillosis in Critically Ill Patients with Hematological Malignancies and Septic Shock

INTRODUCTION

Invasive pulmonary aspergillosis (IPA) is an important cause of morbidity/mortality in critically ill patients with hematological malignancies. New diagnosis strategies include the noninvasive biomarkers 1,3-beta-D-glucan (BDG) and serum galactomannan (GM).

METHODS

For early detection of IPA, we compared BDG Fungitell assay with GM Platelia assay.

RESULTS

Twenty-two out of 30 patients (74 %) had elevated BDG levels (mean 306 pg/ml) beyond the cutoff of 80 pg/ml. GM levels were elevated in only 3 patients (10 %) over the ODI cutoff of >0.5. Following the BDG/GM and microbiological findings, 10 (34 %) cases were classified as probable IPA and 12 (40 %) as possible IPA. Eight (26 %) were classified as no IPA. An overall sensitivity of 90 % (95 % CI 86-96 %) and specificity of 85 % (95 % CI 79-86 %) was found for the BDG Fungitell assay in IPA. In contrast, an overall sensitivity of 30 % (95 % CI 26-38 %) and specificity of 98 % (95 % CI 94-100 %) was found for the GM Platelia assay. A false-negative rate of 70 % for probable IPA and 85 % for probable/possible IPA was detected for GM. The false-negative rate for BDG was 0 % in cases of probable IPA and 45 % in cases of possible cases.

CONCLUSION

BDG is a sensitive marker for patients' surveillance at risk of IPA. In patients with hematological malignancies and septic shock, early diagnosis of IPA might be significantly improved by BDG compared to GM, also considering that BDG has the advantage of detecting fungal diseases other than IPA.

Comparison of galactomannan, beta-D-glucan, and Aspergillus DNA in sera of high-risk adult patients with hematological malignancies for the diagnosis of invasive aspergillosis

BACKGROUND/AIM

Invasive aspergillosis (IA) is a fatal infection that is difficult to diagnose in immunocompromised patients. In this study, Aspergillus-specific DNA was searched using real-time PCR (RT-PCR) in serum samples. Galactomannan (GM) and/or beta-D-glucan (BDG) tests were previously performed on these samples for 70 neutropenic patients with hematological malignancy.

MATERIALS AND METHODS

The patients were categorized according to the criteria of the European Organization for Research and Treatment of Cancer/Mycoses Study Group (EORTC/MSG). Among the patient serum samples, the first positive GM or BDG test sample and the median sample of GM or BDG test for negative patients were used to detect DNA levels by RT-PCR method (Light Cycler 480, Roche Molecular Biochemicals, Meylan, France) using a commercial kit (Way2Gene Fungi; Genmar, İzmir, Turkey).

RESULTS

When the proven and probable IA group were considered as real patients, sensitivity of Aspergillus-specific DNA test was 90%, specificity was 73.3%, positive predictive value was 81.8%, and negative predictive value was 84.6%.

CONCLUSION

This study found that searching for specific DNA by RT-PCR method has a sensitivity as high as the GM test. Although specificity was rather low, it was concluded that it can be used jointly with GM and BDG tests after decreasing contamination by severe laboratory applications.

How to manage lung infiltrates in adults suffering from haematological malignancies outside allogeneic haematopoietic stem cell transplantation

Pulmonary complications affect up to 40% of patients with severe neutropenia lasting for more than 10 d. As they are frequently associated with fever and elevation of C‐reactive protein or other signs of inflammation, they are mostly handled as pneumonia. However, the differential diagnosis is broad, and a causative microbial agent remains undetected in the majority of cases. Pulmonary side effects from cytotoxic treatment or pulmonary involvement by the underlying malignancy must always be taken into account and may provide grounds for invasive diagnostic procedures in selected patients. Pneumocystis jirovecii (in patients not receiving co‐trimoxazole as prophylaxis), multi‐resistant gram‐negative bacilli, mycobacteria or respiratory viruses may be involved. High‐risk patients may be infected by filamentous fungi, such as Aspergillus spp., but these infections are seldom proven when treatment is initiated. Microorganisms isolated from cultures of blood, bronchoalveolar lavage or respiratory secretions need careful interpretation as they may be irrelevant for determining the aetiology of pulmonary infiltrates, particularly when cultures yield coagulase‐negative staphylococci, enterococci or Candida species. Non‐culture based diagnostics for detecting Aspergillus galactomannan, beta‐D‐glucan or DNA from blood, bronchoalveolar lavage or tissue samples can facilitate the diagnosis, but must always be interpreted in the context of clinical and imaging findings. Systemic antifungal treatment with mould‐active agents, given in combination with broad‐spectrum antibiotics, improves clinical outcome when given pre‐emptively. Co‐trimoxazole remains the first‐line treatment for Pneumocystis pneumonia, while cytomegalovirus pneumonia will respond to ganciclovir or foscarnet in most cases. The clinical outcome of acute respiratory failure can also be successful with proper intensive care, when indicated.

Clinical validity of bis(methylthio)gliotoxin for the diagnosis of invasive aspergillosis

Early and accurate diagnosis of invasive aspergillosis (IA) is one of the most critical steps needed to efficiently treat the infection and reduce the high mortality rates that can occur. We have previously found that the Aspergillus spp. secondary metabolite, bis(methylthio)gliotoxin (bmGT), can be detected in the serum from patients with possible/probable IA. Thus, it could be used as a diagnosis marker of the infection. However, there is no data available concerning the sensitivity, specificity and performance of bmGT to detect the infection. Here, we have performed a prospective study comparing bmGT detection with galactomannan (GM), the most frequently used and adopted approach for IA diagnosis, in 357 sera from 90 episodes of patients at risk of IA. Our results, involving 79 patients that finally met inclusion criteria, suggest that bmGT presents higher sensitivity and positive predictive value (PPV) than GM and similar specificity and negative predictive value (NPV). Importantly, the combination of GM and bmGT increased the PPV (100 %) and NPV (97.5 %) of the individual biomarkers, demonstrating its potential utility in empirical antifungal treatment guidance and withdrawal. These results indicate that bmGT could be a good biomarker candidate for IA diagnosis and, in combination with GM, could result in highly specific diagnosis of IA and management of patients at risk of infection.

Direct comparison of galactomannan performance in concurrent serum and bronchoalveolar lavage samples in immunocompromised patients at risk for invasive pulmonary aspergillosis

Invasive pulmonary aspergillosis (IPA) is a life-threatening infection mainly affecting immunocompromised patients. Early diagnosis is critical, but the diagnostic gold standard (histopathology and culture) is time consuming and cannot offer early confirmation of IPA. Fungal biomarkers like galactomannan (GM) are a promising extension to the diagnostic repertoire. However, it still remains under discussion if biomarker analysis from the site of the infection is superior to testing blood samples. We retrospectively evaluated the diagnostic performance of concurrent serum GM and bronchoalveolar lavage (BAL) GM (obtained within 24 h) of immunocompromised patients at high risk of IPA. Twenty-six proven/probable patients and eight patients with no IPA according to the EORTC/MSG 2008 criteria were included in this study. Sensitivity, specificity, positive predictive value, negative predictive value and diagnostic odds ratio were for BAL GM: 85%, 88%, 96%, 64% and 38.5, and for serum GM: 23%, 88%, 88%, 26% and 2.1 respectively. BAL GM proved to be significantly more sensitive for the detection of IPA compared to same-day serum GM in patients at high risk of IPA (P < 0.0001). Our data show that BAL GM testing is significantly superior to serum GM implying that diagnostic efforts should focus on specimens from the site of infection.

Serum galactomannan levels in the diagnosis of invasive aspergillosis

BACKGROUND/AIMS

In this study, the sensitivity-specificity of galactomannan-enzyme immunoassay (GM-EIA) with a cut-off value of 0.5 for a single, two, or three consecutive positivity in the diagnosis of invasive pulmonary aspergillosis (IPA) in neutropenic patients with hematological malignancy was investigated.

METHODS

IPA was classified as "proven," "probable," or "possible" as described in the guidelines prepared by the European Organization for Research and Treatment of Cancer and Mycoses Study Group." Serum samples were collected from the patients twice a week throughout their hospitalization. A total of 1,385 serum samples, with an average of 8.3 samples per episode, were examined.

RESULTS

Based on the 165 febrile episodes in 106 patients, 80 (48.5%) were classified as IPA (4 proven, 11 probable, 65 possible) and 85 (51.5%) as non-IPA. The sensitivity/ specificity was 100%/27.1% for a single proven/probable IPA with the cut of value of GM-EIA ≥ 0.5, 86.7%/71.8% for two consecutive positive results, and 73.3%/85.9% for three consecutive positive results.

CONCLUSIONS

With the galactomannan levels measured twice a week, consecutive sensitivity decreased and specificity increased. Therefore, an increase may be obtained in sensitivity-specificity by more frequent monitoring of GM-EIA starting from the first day of positivity is detected.

Aspergillus Polymerase Chain Reaction: Systematic Review of Evidence for Clinical Use in Comparison With Antigen Testing

BACKGROUND

Aspergillus polymerase chain reaction (PCR) was excluded from the European Organisation for the Research and Treatment of Cancer/Mycoses Study Group (EORTC/MSG) definitions of invasive fungal disease because of limited standardization and validation. The definitions are being revised.

METHODS

A systematic literature review was performed to identify analytical and clinical information available on inclusion of galactomannan enzyme immunoassay (GM-EIA) (2002) and β-d-glucan (2008), providing a minimal threshold when considering PCR. Categorical parameters and statistical performance were compared.

RESULTS

When incorporated, GM-EIA and β-d-glucan sensitivities and specificities for diagnosing invasive aspergillosis were 81.6% and 91.6%, and 76.9% and 89.4%, respectively. Aspergillus PCR has similar sensitivity and specificity (76.8%-88.0% and 75.0%-94.5%, respectively) and comparable utility. Methodological recommendations and commercial PCR assays assist standardization. Although all tests have limitations, currently, PCR is the only test with independent quality control.

CONCLUSIONS

We propose that there is sufficient evidence that is at least equivalent to that used to include GM-EIA and β-d-glucan testing, and that PCR is now mature enough for inclusion in the EORTC/MSG definitions.

Aspergillus and aspergilloses in wild and domestic animals: a global health concern with parallels to human disease

The importance of aspergillosis in humans and various animal species has increased over the last decades. Aspergillus species are found worldwide in humans and in almost all domestic animals and birds as well as in many wild species, causing a wide range of diseases from localized infections to fatal disseminated diseases, as well as allergic responses to inhaled conidia. Some prevalent forms of animal aspergillosis are invasive fatal infections in sea fan corals, stonebrood mummification in honey bees, pulmonary and air sac infection in birds, mycotic abortion and mammary gland infections in cattle, guttural pouch mycoses in horses, sinonasal infections in dogs and cats, and invasive pulmonary and cerebral infections in marine mammals and nonhuman primates. This article represents a comprehensive overview of the most common infections reported by Aspergillus species and the corresponding diseases in various types of animals.

Diagnosis and antimicrobial therapy of lung infiltrates in febrile neutropenic patients (allogeneic SCT excluded): updated guidelines of the Infectious Diseases Working Party (AGIHO) of the German Society of Hematology and Medical Oncology (DGHO)

Up to 25% of patients with profound neutropenia lasting for >10 days develop lung infiltrates, which frequently do not respond to broad-spectrum antibacterial therapy. While a causative pathogen remains undetected in the majority of cases, Aspergillus spp., Pneumocystis jirovecii, multi-resistant Gram-negative pathogens, mycobacteria or respiratory viruses may be involved. In at-risk patients who have received trimethoprim-sulfamethoxazole (TMP/SMX) prophylaxis, filamentous fungal pathogens appear to be predominant, yet commonly not proven at the time of treatment initiation. Pathogens isolated from blood cultures, bronchoalveolar lavage (BAL) or respiratory secretions are not always relevant for the etiology of pulmonary infiltrates and should therefore be interpreted critically. Laboratory tests for detecting Aspergillus galactomannan, β-D-glucan or DNA from blood, BAL or tissue samples may facilitate the diagnosis; however, most polymerase chain reaction assays are not yet standardized and validated. Apart from infectious agents, pulmonary side-effects from cytotoxic drugs, radiotherapy or pulmonary involvement by the underlying malignancy should be included into differential diagnosis and eventually be clarified by invasive diagnostic procedures. Pre-emptive treatment with mold-active systemic antifungal agents improves clinical outcome, while other microorganisms are preferably treated only when microbiologically documented. High-dose TMP/SMX is first choice for treatment of Pneumocystis pneumonia, while cytomegalovirus pneumonia is treated primarily with ganciclovir or foscarnet in most patients. In a considerable number of patients, clinical outcome may be favorable despite respiratory failure, so that intensive care should be unrestrictedly provided in patients whose prognosis is not desperate due to other reasons.

Detection of Aspergillus-specific antibodies by agar gel double immunodiffusion and IgG ELISA in feline upper respiratory tract aspergillosis

Feline upper respiratory tract aspergillosis (URTA) is an emerging infectious disease. The aims of this study were: (1) to assess the diagnostic value of detection of Aspergillus-specific antibodies using an agar gel double immunodiffusion (AGID) assay and an indirect immunoglobulin G (IgG) ELISA; and (2) to determine if an aspergillin derived from mycelia of Aspergillus fumigatus, Aspergillus niger and Aspergillus flavus can be used to detect serum antibodies against cryptic Aspergillus spp. in Aspergillus section Fumigati. Sera from cats with URTA (group 1: n = 21) and two control groups (group 2: cats with other upper respiratory tract diseases, n = 25; group 3: healthy cats and cats with non-respiratory, non-fungal illness, n = 84) were tested. Isolates from cats with URTA comprised A. fumigatus (n = 5), A. flavus (n = 1) and four cryptic species: Aspergillus felis (n = 12), Aspergillus thermomutatus (Neosartorya pseudofischeri, n = 1), Aspergillus lentulus (n = 1) and Aspergillus udagawae (n = 1). Brachycephalic purebred cats were significantly more likely to develop URTA than other breeds (P = 0.013). The sensitivity (Se) of the AGID was 43% and the specificity (Sp) was 100%. At a cut-off value of 6 ELISA units/mL, the Se of the IgG ELISA was 95.2% and the Sp was 92% and 92.9% for groups 2 and 3 cats, respectively. Aspergillus-specific antibodies against all four cryptic species were detected in one or both assays. Assay Se was not associated with species identity. Detection of Aspergillus-specific antibodies by IgG ELISA has high Se and Sp for diagnosis of feline URTA.

How we treat invasive fungal diseases in patients with acute leukemia: the importance of an individualized approach

Invasive fungal diseases (IFDs) represent an important cause of treatment failure in adults with acute leukemia. Because of leukemia’s heterogeneity, the risk for IFDs is highly variable. We therefore apply a risk-adapted antifungal strategy with strong emphasis on pretreatment and day-15 posttreatment to allow earlier and more individualized interventions. We determine pretreatment risks for IFDs based on 4 factors: (1) host fitness for standard therapy (ie, fit, unfit, or frail); (2) leukemia resistance (high vs low probability of achieving complete remission [CR]); (3) anticipated treatment-related toxicity such as neutropenia, mucositis, and steroid-induced immunosuppression; and (4) patient exposure to opportunistic fungi. Accordingly, we stratify patients as high, intermediate, or low risk for IFDs and apply risk-adapted antifungal strategies, including primary or secondary prophylaxis and diagnostic-based preemptive or empiric therapy. Prevention of IFDs also relies on optimizing organ function, decreasing exposure to opportunistic fungi, and improving net state of immunosuppression with use of better-tolerated and investigational agents for unfit patients and those with adverse leukemia biology. Novel targeted and safe therapies that can achieve higher rates of sustained CR among patients with adverse genetics offer the best promise for reducing the burden of IFDs in these patients.

Aspergillus fumigatus and related species

The genus Aspergillus contains etiologic agents of aspergillosis. The clinical manifestations of the disease range from allergic reaction to invasive pulmonary infection. Among the pathogenic aspergilli, Aspergillus fumigatus is most ubiquitous in the environment and is the major cause of the disease, followed by Aspergillus flavus, Aspergillus niger, Aspergillus terreus, Aspergillus nidulans, and several species in the section Fumigati that morphologically resemble A. fumigatus. Patients that are at risk for acquiring aspergillosis are those with an altered immune system. Early diagnosis, species identification, and adequate antifungal therapy are key elements for treatment of the disease, especially in cases of pulmonary invasive aspergillosis that often advance very rapidly. Incorporating knowledge of the basic biology of Aspergillus species to that of the diseases that they cause is fundamental for further progress in the field.

Use and limits of (1-3)-β-d-glucan assay (Fungitell), compared to galactomannan determination (Platelia Aspergillus), for diagnosis of invasive aspergillosis

This study was undertaken to examine the performance of the Fungitell β-glucan (BG) assay, to compare it with that of the galactomannan (GM) test for the diagnosis of invasive aspergillosis (IA) in patients with hematological malignancies, and to examine the rates of false-positive BG and GM test results due to β-lactam antibiotics among sera of patients with Gram-positive or Gram-negative bacteremia and selected sera with false-positive results from the GM test. Serum samples from 105 patients with proven (n = 14) or probable (n = 91) IA, 97 hematology patients at risk for invasive fungal infections, 50 healthy blood donors, and 60 patients with bacteremia were used to study the sensitivities and specificities of the assays. The GM test was more specific than the BG assay (97% versus 82%, respectively; P = 0.0001) and the BG assay was more sensitive than the GM test (81% versus 49%, respectively; P < 0.0001) for IA diagnosis. The study of 49 separate batches of β-lactam antibiotics showed high and very similar rates of false-positive results for the GM and BG assays (29 and 33%, respectively; P = 0.82) but with an almost complete lack of concordance between the 2 assays. For patients with bacteremia, the rate of false-positive results was much higher with the BG test than with the GM test (37% versus 2%, respectively; P < 0.0001), with no significant difference between Gram-positive and Gram-negative bacteremia. In conclusion, the BG test may be useful for the diagnosis of IA because of its high sensitivity in comparison with the GM test, but the overall benefit of this assay remains limited because of its inadequate specificity and its cost.

Fungal diagnostics

Early diagnosis of fungal infection is critical to effective treatment. There are many impediments to diagnosis such as a diminishing number of clinical mycologists, cost, time to result, and requirements for sensitivity and specificity. In addition, fungal diagnostics must meet the contrasting needs presented by the increasing diversity of fungi found in association with the use of immunosuppressive agents in countries with high levels of medical care and the need for diagnostics in resource-limited countries where large numbers of opportunistic infections occur in patients with AIDS. Traditional approaches to diagnosis include direct microscopic examination of clinical samples, histopathology, culture, and serology. Emerging technologies include molecular diagnostics and antigen detection in clinical samples. Innovative new technologies that use molecular and immunoassay platforms have the potential to meet the needs of both resource-rich and resource-limited clinical environments.

Antifungal pre-emptive strategy for high-risk neutropenic patients: why the story is still ongoing

Neutropenic patients with haematological malignancies are at high risk of invasive fungal disease (IFD). Due to limitations in specific procedures to establish an early diagnosis of IFD, two historical unpowered studies suggested, three decades ago, that giving an empirical antifungal treatment to patients with persistent or recurrent fever under broad-spectrum antibacterials, could reduce the risk of IFD. For cost and toxicity reasons, this strategy became debated when modern imaging and indirect biological markers became available. Different pre-emptive strategies, either based on lung imaging, galactomannan antigenaemia, fungal PCR, or a combination of several parameters, were designed with the goal of restricting the administration of antifungals to the more at-risk patients with early signs of IFD. Almost all pre-emptive studies showed or suggested a reduction of administration and cost of antifungals during neutropenic phases. However, the clinical pertinence and safety of the strategy, and mainly its optimal design, are still pending. This paper reviews the evolution of these strategies and how they may be implemented in the haematology ward.

Invasive pulmonary aspergillosis

In susceptible patients, invasive aspergillosis has a high incidence and a mortality of up to 80%. The diagnosis of this condition is difficult, especially in the early stages of the disease and, as a consequence, antifungal therapy, despite its expense and toxicity, is often initiated empirically. Until recently, there were very few effective antifungal agents for established invasive aspergillosis, but the introduction of two new drugs, voriconazole and caspofungin, has increased the treatment options. These newer antifungal therapies, combined with improved early diagnosis due to the introduction of newer microbiologic techniques, offer the hope that there will be a significant improvement in the substantial morbidity and mortality associated with invasive aspergillosis over the next 5 years.

Galactomannan antigen detection in the diagnosis of invasive aspergillosis

Invasive aspergillosis is a serious and lethal infection among immunocompromised patients, with reported mortality rates as high as 74-92%. The high mortality is related to the severe immunosuppression experienced by these patients as well as the difficulties for physicians in arriving at a timely diagnosis. Definitive diagnostic procedures (tissue biopsy for histopathology and culture) are often precluded by severe cytopenias and coagulation abnormalities. The development of minimally invasive, nonculture diagnostic methods is a major advance in the early diagnosis of invasive aspergillosis. Galactomannan is a heteropolysaccharide (mannan core and side residues of galactofuranosyl units) present in the cell wall of Aspergillus spp. The double sandwich enzyme immunoassay, which detects galactomannan in serum samples, has been available in Europe for almost a decade and in the USA since May 2003, for the diagnosis of invasive aspergillosis. However, availability of the double galactomannan enzyme immunoassay is center variable in the USA and, although its analytical performance in the diagnosis of invasive aspergillosis is well documented, its routine use in clinical practice is limited. As an adjunct in the diagnosis and management of invasive aspergillosis, incorporation of the galactomannan enzyme immunoassay into clinical trials will help to further define its role.

Fungal infections of the central nervous system

The epidemiology of invasive fungal infections in immunocompromised patients is rapidly changing. Several of the fungi have worldwide distribution. However, some have specific geographical distribution. Sinocranial aspergillosis, mostly described from countries with temperate climates, occurs mostly in otherwise immunocompetent individuals Most of the systemic fungal pathogens have been associated with central nervous system (CNS) involvement. The major advances in CNS fungal infections are in the pathobiology, new diagnostic tools, and new therapies. In spite of these developments, there is still considerable delay in the diagnosis of CNS fungal infection. CNS fungal infections are associated with considerable morbidity and mortality. To achieve good outcomes early diagnosis and early institution of appropriate therapies are the key issues.

Aspergillus colonization in patients with bronchogenic carcinoma

Background

Aspergillus antigens such as galactomannan antigen, a cell wall polysaccharide, can be detected in patient’s serum or bronchoalveolar lavage. To study the prevalence of Aspergillus infection in patients with bronchogenic carcinoma, we measured galactomannan antigen in serum and bronchoalveolar lavage samples of patients with bronchogenic carcinoma.

Methods

The study was conducted on 45 bronchogenic carcinoma patients. The diagnosis of lung cancer was confirmed by bronchoscopy, histopathological and radiological examinations. Bronchoalveolar lavage fluid collected from each patient by fiberoptic bronchoscopy was subjected to direct microscopy and culture on Sabouraud’s dextrose agar and Czapek-Dox agar, and Aspergillus galactomannan antigen was measured in serum and bronchoalveolar lavage samples.

Results

The majority of patients were male (93.3%) in the age group 51–60 years, 88.9% were addicted to gutka chewing, and 82.1% were addicted to smoking. Most patients complained of cough (73%) and shortness of breath (51.1%). Squamous cell carcinoma (64.4%) was the most common malignancy, followed by adenocarcinoma (13.3%). On culture of bronchoalveolar lavage samples, 35.5% showed growth of Aspergillus spp. ( Aspergillus fumigatus in 17.8%, Aspergillus flavus in 13.3%, and Aspergillus niger in 4.4%). Galactomannan antigen was detected in 58.3% of bronchoalveolar lavage samples and 47.2% of serum samples.

Conclusions

There is a high prevalence of aspergillosis in patients with lung carcinoma, especially among smokers and gutka chewers.