Beta-D-glucan detection as a diagnostic test for invasive aspergillosis in immunocompromised critically ill patients with symptoms of respiratory infection: an autopsy-based study

Diagnostic limitations and challenges in current clinical guidelines and potential application of metagenomic sequencing to manage pulmonary invasive fungal infections in patients with haematological malignancies

BACKGROUND

Pulmonary invasive fungal infections (pIFI) disproportionately affect patients with haematological malignancies (HM). Establishing a rapid and accurate diagnosis of pIFI is challenging. Multiple guidelines recommend diagnostic testing of invasive fungal infections but lack consensus and may contribute to inconsistent diagnostic approaches.

OBJECTIVE

To identify key diagnostic challenges and review metagenomic sequencing data.

SOURCES

PubMed, professional consortium, and scientific society websites search to identify relevant, published, evidence-based clinical guidelines within the past 5 years. PubMed searchs for papers describing clinically relevant novel diagnostic technologies.

CONTENT

Current guidelines for patients with HM and suspected pIFI recommend chest computed tomography imaging and specimen testing with microscopic examination (including calcofluor white stain, histopathology, cytopathology, etc.), Aspergillus galactomannan, β-D-glucan, PCR, and culture, each with certain limitations. Emerging real-world data support the adjunctive use of metagenomic sequencing-based tests for the timely diagnosis of pIFI.

IMPLICATIONS

High-quality evidence from robust clinical trials is needed to determine whether guidelines should be updated to include novel diagnostic technologies. Trials should ask whether the combination of powerful novel diagnostics, such as pathogen-agnostic metagenomic sequencing technologies in conjunction with conventional testing can optimize the diagnostic yield for all potential pIFI pathogens that impact the health of patients with HM.

Fungal Abscess of Anterior Nasal Septum Complicating Maxillary Sinus Fungal Ball Rhinosinusitis Caused by Aspergillus flavus: Case Report and Review of Literature

Anterior nasal septum abscess is not a rare clinical disease entity. In terms of the etiologies of the disease, bacteria are obviously more common than fungi. Fungal culture and pathological examination are essential for diagnosis of a fungal abscess of the anterior nasal septum and the basis of prescription of antifungal agents. We report a 57-year-old male patient who came to our outpatient clinic due to refractory nasal congestion for 3 weeks despite receiving treatments by a local medical doctor. Radical surgery with postoperative adjuvant radiotherapy for the right buccal cancer was carried out 14 years ago. The patient has diabetes mellitus and the blood sugar level has been well controlled by oral hypoglycemic agents over the past several years. Computed tomography revealed an abscess in the anterior septum along with rhinosinusitis. Incision and drainage of the nasal septum abscess and functional endoscopic sinus surgery were carried out. Fungal culture and pathological examination confirmed a fungal abscess in the anterior nasal septum and fungal ball rhinosinusitis. Antibiotics and an antifungal agent were given, and the postoperative course was uneventful. A dialectical argument was made regarding the causal relationship between the fungal abscess of the anterior nasal septum and maxillary fungal ball sinusitis. A literature review of the previous case reports was carried out to elucidate the immune status of patients of this disease. In order to reach a rapid establishment of a fungal abscess of the anterior nasal septum, clinicians should keep this disease in mind and remain vigilant. An immuno-compromised status is more commonly found in patients with fungal abscess of the anterior nasal septum and is another important characteristic of this disease. Prompt diagnosis and effective treatment are equally important in patients with lower immune status of this kind, and the latter is based on the former.

Fungal infections in liver cirrhosis

Liver cirrhosis is a chronic condition that is associated with a variety of complications across organ systems. Patients with cirrhosis also suffer from immune dysfunction, which may predispose them to catastrophic bacterial and fungal infections. Bacterial infections in liver cirrhosis have been well-documented, however, data remains scarce regarding fungal infections. Candida and Aspergillus have been reported as the most common pathogens among patients with cirrhosis, causing both invasive and non-invasive infections. However, other pathogens such as Coccidioides, Pneumocystis, Cryptococcus, and Rhizopus have been increasing in incidence. Diagnosis of fungal infection is often difficult, particularly in regards to distinguishing colonization from invasive infection. Serum markers such as beta-D-glucan (BDG) and galactomannan are beneficial diagnostic tools in conjunction with fungal cultures and imaging modalities. Bronchoscopy with bronchoalveolar lavage (BAL) or lung biopsy can be useful adjuncts as well. Liver transplantation is another important consideration as invasive fungal infection (IFI) is a contraindication to transplant surgery. Additionally, patients are at increased risk for infection due to immunosuppression in the post-transplant period. We aim to discuss the mechanisms responsible for immune dysfunction in advanced liver disease, the epidemiology of fungal infections in this population, as well as presentations and management considerations pertaining to specific pathogens and antifungal regimens.

Acute lymphoblastic leukemia with central nervous system Aspergillus infection: A case report and literature review

Ubiquitous in nature, Aspergillus rarely invades the brain to induce infection in general. However, in clinical practice, some patients with hematological malignancies or immunosuppression may suffer from Aspergillus infection of the central nervous system, which arises most commonly as a result of hematogenous dissemination from a pulmonary focus or direct extension from the paranasal sinus infection. Treatment is clinically challenging and the mortality rate is relatively high. Recently, a case diagnosed with acute lymphocytic leukemia was admitted to the Department of Neurosurgery, The First People's Hospital of Huzhou (First Affiliated Hospital of Huzhou University, Huzhou, China). During chemotherapy, space-occupying lesions were observed in the right occipital lobe of the patient, and lesion progression was captured. After treatment with surgery, an analysis of specimens collected from the patient was performed and was suggestive of Aspergillus infection. Following the symptomatic therapy with voriconazole, the patient's disease prognosis was favorable. The focus of infection due to pulmonary aspergillosis or Aspergillus sinusitis was not detected in the patient and the focus was not a common site of hematogenous infection. In addition, the patient exhibited no obvious clinical symptoms. In view of the above observations, the possibility of hospital-acquired infection was considered, to which clinicians should be alert.

Impact of intravenous immunoglobulins on serum (1-3)-β-D-Glucan

BACKGROUND

The purpose of this study was to evaluate the changes in serum (1-3)-β-D-glucan (BDG) in adults due to intravenous immunoglobulins (IVIG) infusion and the factors that affect these changes.

METHODS

Patients who had BDG tests both before and after IVIG infusion during hospitalization were retrospectively included, and trends in BDG values were analyzed before and after IVIG infusion. Factors associated with false-positive BDG were then explored using univariate analysis.

RESULTS

A total of 347 serum BDG tests from 131 patients were included in the analysis, and 71.8% (94/131) patients had false positive serum BDG after IVIG infusion. All BDG values on day 7 were negative. Univariate analysis showed that patients with false positive BDG tests had higher daily IVIG doses (P = 0.043) and higher levels of serum IgG increments (P = 0.001). The median peak blood BDG on day 1 after completion of IVIG infusion was 199.6 (154.5-277.7, inter-quartile ranges (IQR)) pg/mL, and both the peak BDG and incremental BDG values (ΔBDG, BDG at the first day after IVIG infusion minus BDG before infusion) were slightly and positively correlated with ΔIgG (BDG vs. ΔIgG, P = 0.0016; ΔBDG vs. ΔIgG, P = 0.0003).

CONCLUSION

Most adults showed false positive BDG tests after IVIG infusion and negative BDG tests within 1 week. Daily IVIG dosage may contribute to the evaluation of ΔBDG.

Assessment of the Role of 1,3-β-d-Glucan Testing for the Diagnosis of Invasive Fungal Infections in Adults

Detection of 1,3-β-d-glucan (BDG) in serum has been evaluated for its inclusion as a mycological criterion of invasive fungal infections (IFI) according to EORTC and Mycoses Study Group (MSG) definitions. BDG testing may be useful for the diagnosis of both invasive aspergillosis and invasive candidiasis, when interpreted in conjunction with other clinical/radiological signs and microbiological markers of IFI. However, its performance and utility vary according to patient population (hematologic cancer patients, solid-organ transplant recipients, intensive care unit patients) and pretest likelihood of IFI. The objectives of this article are to provide a systematic review of the performance of BDG testing and to assess recommendations for its use and interpretation in different clinical settings.

Clinical Usefulness of Serum (1,3)-β-D-glucan to predict invasive candidiasis in patients with severe burn trauma

BACKGROUND

(1,3)-β-D-glucan (BD) assays were developed as a method to rapidly diagnose invasive candidiasis (IC). The incidence of fungal infections and the demands for BD assay are gradually increasing in patients with severe trauma and under intensive care. However, the ideal BD cut-off value to predict IC has not been clarified. In this study, we evaluate the predictability of the BD assay and investigate the optimal cut-off value in patients with severe burn injuries.

METHODS

From July to December 2018, 134 samples from 86 patients with severe burns were analyzed. Serum BD levels were measured utilizing a Fungitell (Cape Cod Inc.) assay. A receiver operator characteristic (ROC) curve was generated, and the cumulative progression of IC was studied using a Cox proportional hazards model. Partial dependence plots (PDP) was applied to predict the risk of IC.

RESULTS

Eleven patients were diagnosed with IC. BD over 120 pg/mL (HR = 5.11; P = 0.001) was found to be independent predictor of the occurrence of IC, when the multivariable Cox model was adjusted for age, total body surface area, and inhalation injury. The area under the ROC curve was 0.658 (95% CI, 0.513-0.803), at an optimal cut-off value of 124.7 pg/mL. PDP analysis showed the higher predicted IC occurrence at a BD level of ∼120-150 pg/mL and TBSA over 60%.

CONCLUSION

Our findings suggest that BD is an independent predictor for IC, and that a BD level between 120 and 150 pg/mL could be utilized for IC prediction.

Occurrence of Invasive Pulmonary Fungal Infections in Patients with Severe COVID-19 Admitted to the ICU

Rationale: Whether severe coronavirus disease (COVID-19) is a significant risk factor for the development of invasive fungal superinfections is of great medical interest and remains, for now, an open question.Objectives: We aim to assess the occurrence of invasive fungal respiratory superinfections in patients with severe COVID-19.Methods: We conducted the study on patients with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-related pneumonia admitted to five ICUs in France who had respiratory and serum sampling performed for specific screening of fungal complications.Measurements and Main Results: The study population included a total of 145 patients; the median age was 55 years old. Most of them were male (n = 104; 72%), were overweight (n = 99; 68%), and had hypertension (n = 83; 57%) and diabetes (n = 46; 32%). Few patients presented preexisting host risk factors for invasive fungal infection (n = 20; 14%). Their global severity was high; all patients were on invasive mechanical ventilation, and half (n = 73, 54%) were on extracorporeal membrane oxygenation support. Mycological analysis included 2,815 mycological tests (culture, galactomannan, β-glucan, and PCR) performed on 475 respiratory samples and 532 sera. A probable/putative invasive pulmonary mold infection was diagnosed in 7 (4.8%) patients and linked to high mortality. Multivariate analysis indicates a significantly higher risk for solid organ transplant recipients (odds ratio,  = 4.66; interquartile range, 1.98-7.34; P = 0.004). False-positive fungal test and clinically irrelevant colonization, which did not require the initiation of antifungal treatment, was observed in 25 patients (17.2%).Conclusions: In patients with no underlying immunosuppression, severe SARS-CoV-2-related pneumonia seems at low risk of invasive fungal secondary infection, especially aspergillosis.

Johnson E, Littlechild J, Winlove CP, Vollmer F, Gow NAR. Biosensors and Diagnostics for Fungal Detection

Early detection is critical to the successful treatment of life-threatening infections caused by fungal pathogens, as late diagnosis of systemic infection almost always equates with a poor prognosis. The field of fungal diagnostics has some tests that are relatively simple, rapid to perform and are potentially suitable at the point of care. However, there are also more complex high-technology methodologies that offer new opportunities regarding the scale and precision of fungal diagnosis, but may be more limited in their portability and affordability. Future developments in this field are increasingly incorporating new technologies provided by the use of new format biosensors. This overview provides a critical review of current fungal diagnostics and the development of new biophysical technologies that are being applied for selective new sensitive fungal biosensors to augment traditional diagnostic methodologies.

Confronting and mitigating the risk of COVID-19 associated pulmonary aspergillosis

The coronavirus disease 2019 (COVID-19) virus caused a wide spectrum of disease in healthy individuals, as well as those with common comorbidities [1]. Severe COVID-19 is characterised by acute respiratory distress syndrome (ARDS) secondary to viral pneumonitis, treatment of which may require mechanical ventilation or extracorporeal membrane oxygenation [2]. Clinicians are alert to the possibility of bacterial co-infection as a complication of lower respiratory tract viral infection; for example, a recent review found that 72% of patients with COVID-19 received antimicrobial therapy [3]. However, the risk of fungal co-infection, in particular COVID-19 associated pulmonary aspergillosis (CAPA), remains underappreciated.

Cases of COVID-19 associated pulmonary aspergillosis (CAPA) are being increasingly reported and physicians treating patients with COVID-19-related lung disease need to actively consider these fungal co-infections https://bit.ly/3feuGsQ

(1→3)-β-D-glucan testing for the detection of invasive fungal infections in immunocompromised or critically ill people

BACKGROUND

Invasive fungal infections (IFIs) are life-threatening opportunistic infections that occur in immunocompromised or critically ill people. Early detection and treatment of IFIs is essential to reduce morbidity and mortality in these populations. (1→3)-β-D-glucan (BDG) is a component of the fungal cell wall that can be detected in the serum of infected individuals. The serum BDG test is a way to quickly detect these infections and initiate treatment before they become life-threatening. Five different versions of the BDG test are commercially available: Fungitell, Glucatell, Wako, Fungitec-G, and Dynamiker Fungus.

OBJECTIVES

To compare the diagnostic accuracy of commercially available tests for serum BDG to detect selected invasive fungal infections (IFIs) among immunocompromised or critically ill people.

SEARCH METHODS

We searched MEDLINE (via Ovid) and Embase (via Ovid) up to 26 June 2019. We used SCOPUS to perform a forward and backward citation search of relevant articles. We placed no restriction on language or study design.

SELECTION CRITERIA

We included all references published on or after 1995, which is when the first commercial BDG assays became available. We considered published, peer-reviewed studies on the diagnostic test accuracy of BDG for diagnosis of fungal infections in immunocompromised people or people in intensive care that used the European Organization for Research and Treatment of Cancer (EORTC) criteria or equivalent as a reference standard. We considered all study designs (case-control, prospective consecutive cohort, and retrospective cohort studies). We excluded case studies and studies with fewer than ten participants. We also excluded animal and laboratory studies. We excluded meeting abstracts because they provided insufficient information.

DATA COLLECTION AND ANALYSIS

We followed the standard procedures outlined in the Cochrane Handbook for Diagnostic Test Accuracy Reviews. Two review authors independently screened studies, extracted data, and performed a quality assessment for each study. For each study, we created a 2 × 2 matrix and calculated sensitivity and specificity, as well as a 95% confidence interval (CI). We evaluated the quality of included studies using the Quality Assessment of Studies of Diagnostic Accuracy-Revised (QUADAS-2). We were unable to perform a meta-analysis due to considerable variation between studies, with the exception of Candida, so we have provided descriptive statistics such as receiver operating characteristics (ROCs) and forest plots by test brand to show variation in study results.

MAIN RESULTS

We included in the review 49 studies with a total of 6244 participants. About half of these studies (24/49; 49%) were conducted with people who had cancer or hematologic malignancies. Most studies (36/49; 73%) focused on the Fungitell BDG test. This was followed by Glucatell (5 studies; 10%), Wako (3 studies; 6%), Fungitec-G (3 studies; 6%), and Dynamiker (2 studies; 4%). About three-quarters of studies (79%) utilized either a prospective or a retrospective consecutive study design; the remainder used a case-control design. Based on the manufacturer's recommended cut-off levels for the Fungitell test, sensitivity ranged from 27% to 100%, and specificity from 0% to 100%. For the Glucatell assay, sensitivity ranged from 50% to 92%, and specificity ranged from 41% to 94%. Limited studies have used the Dynamiker, Wako, and Fungitec-G assays, but individual sensitivities and specificities ranged from 50% to 88%, and from 60% to 100%, respectively. Results show considerable differences between studies, even by manufacturer, which prevented a formal meta-analysis. Most studies (32/49; 65%) had no reported high risk of bias in any of the QUADAS-2 domains. The QUADAS-2 domains that had higher risk of bias included participant selection and flow and timing.

AUTHORS' CONCLUSIONS

We noted considerable heterogeneity between studies, and these differences precluded a formal meta-analysis. Because of wide variation in the results, it is not possible to estimate the diagnostic accuracy of the BDG test in specific settings. Future studies estimating the accuracy of BDG tests should be linked to the way the test is used in clinical practice and should clearly describe the sampling protocol and the relationship of time of testing to time of diagnosis.

Azole-Resistant COVID-19-Associated Pulmonary Aspergillosis in an Immunocompetent Host: A Case Report

COVID-19-associated pulmonary aspergillosis (CAPA) is a recently described disease entity affecting patients with severe pulmonary abnormalities treated in intensive care units. Delays in diagnosis contribute to a delayed start of antifungal therapy. In addition, the emergence of resistance to triazole antifungal agents puts emphasis on early surveillance for azole-resistant Aspergillus species. We present a patient with putative CAPA due to Aspergillus fumigatus with identification of a triazole-resistant isolate during therapy. We underline the challenges faced in the management of these cases, the importance of early diagnosis and need for surveillance given the emergence of triazole resistance.

Gut leakage enhances sepsis susceptibility in iron-overloaded β-thalassemia mice through macrophage hyperinflammatory responses

Iron overload induces intestinal-permeability defect (gut leakage), and gut translocation of organismal molecules might enhance systemic inflammation and sepsis severity in patients with thalassemia (Thal). Hence, iron administration in Hbb^th3/+ mice, heterozygous β-globin-deficient Thal mice, was explored. Oral iron administration induced more severe secondary hemochromatosis and gut leakage in Thal mice compared with wild-type (WT) mice. Gut leakage was determined by 1) FITC-dextran assay, 2) spontaneous serum elevation of endotoxin (LPS) and (1→3)-β-d-glucan (BG), molecular structures of gut-organisms, and 3) reduction of tight-junction molecules with increased enterocyte apoptosis (activated caspase-3) by immunofluorescent staining. Iron overload also enhanced serum cytokines and increased Bacteroides spp. (gram-negative bacteria) in feces as analyzed by microbiome analysis. LPS injection in iron-overloaded Thal mice produced higher mortality and prominent cytokine responses. Additionally, stimulation with LPS plus iron in macrophage from Thal mice induced higher cytokines production with lower β-globin gene expression compared with WT. Furthermore, possible gut leakage as determined by elevated LPS or BG (>60 pg/mL) in serum without systemic infection was demonstrated in 18 out of 41 patients with β-thalassemia major. Finally, enhanced LPS-induced cytokine responses of mononuclear cells from these patients compared with cells from healthy volunteers were demonstrated. In conclusion, oral iron administration in Thal mice induced more severe gut leakage and increased fecal gram-negative bacteria, resulting in higher levels of endotoxemia and serum inflammatory cytokines compared with WT. Preexisting hyperinflammatory cytokines in iron-overloaded Thal enhanced susceptibility toward infection.NEW & NOTEWORTHY Although the impact of iron accumulation in several organs of patients with thalassemia is well known, the adverse effect of iron accumulation in gut is not frequently mentioned. Here, we demonstrated iron-induced gut-permeability defect, impact of organismal molecules from gut translocation of, and macrophage functional defect upon the increased sepsis susceptibility in thalassemia mice.

Paediatric mucormycosis: tailoring surgical strategies to compliment antifungal chemotherapy. Different strokes for different folks

Children manifesting soft-tissue fungal infections are uncommonly seen, more so the subgroup of invasive soft-tissue mucormycosis. Invasive fungal infections in various organs respond differently and are often complicated by an immune-compromised host. Repeated and aggressive clearance of disease till an infection-clear margin is obtained is the mainstay of surgical therapy. This is coupled with appropriate antifungal therapy and the management of any underlying medical conditions. From our experience, we propose a surgical algorithm for therapy of soft-tissue mucormycosis in children.

Acute Pulmonary Aspergillosis as a Severe Complication of Influenza, Pneumococcal Pneumonia, and Staphylococcus aureus Bacteremia in ICU

Background. Acute aspergillosis is a disease with dramatic progression and high mortality if not treated rapidly. However, diagnosing and treating is challenging, as the risk factors are not fully understood. Case Presentation. A fifty-three-year-old woman without any comorbidities was admitted to hospital due to high fever. Infections with influenza and pneumonia and Staphylococcus aureus bacteremia were diagnosed. The patient improved at first due to antimicrobial therapy; nine days after admission, her clinical condition deteriorated again, and she was transferred to ICU due to septic shock accompanied by respiratory failure, necessitating mechanical ventilation and high-dose catecholamine support. A CT scan showed a resolving inflammatory infiltrate bilateral caverns with markedly thickened walls. A culture from a bronchoalveolar lavage grew Aspergillus fumigatus. Galactomannan testing was positive in a bronchoalveolar lavage sample, and beta-D-glucan was positive in serum. Antifungal therapy with voriconazole and intermittent isavuconazole due to renal failure was performed, followed by a surgical resection of the caverns. Patient’s recovery was complicated by several severe bleeding episodes in the lungs. However, the patient showed full recovery and was discharged after 109 days in hospital. Conclusions. This case report highlights multiple complications of influenza and the difficulties of diagnosing and treating acute pulmonary aspergillosis. Furthermore, it stresses the importance for further studies to deepen the understanding about the association between influenza and aspergillosis and to shed further light on adequate therapy.

Invasive aspergillosis in critically ill patients: An autopsy study

Autopsy studies show that IA is among the most commonly missed diagnoses in critically ill patients. And, because of lack of unequivocal diagnostic criteria, a timely diagnosis remains challenging. We investigate the epidemiology of and the clinical risk factors for IA in critically ill patients. We conducted a retrospective, observational study of all consecutive ICU patients with evidence of IA in the postmortem examination. During the period of the study (25 years), 893 postmortem examinations were performed in the ICU. Twenty-five patients (2.8%) were diagnosed with IA in autopsy. Only ten (40%) were classified as IA ante-mortem, based on the initiation of antifungal treatment. The most common comorbid conditions were corticosteroid treatment (n = 14, 56%), chronic obstructive pulmonary disease (COPD) (n = 11, 44%), immunosuppression (n = 6, 24%) and haematological malignancy (n = 5, 20%). Twenty-three patients (92%) had three or more risk factors for IA. Critically ill patients with pulmonary infiltrates, treated with high doses intravenous corticosteroids (even for a short period of time), particularly COPD patients who developed worsening respiratory insufficiency despite appropriate treatment were at the highest risk of IA.

Diagnostic Efficacy of Serum 1,3-β-D-glucan for Invasive Fungal Infection: An Update Meta-Analysis Based on 37 Case Or Cohort Studies

Objective

The aim of this study was to investigate the diagnostic performance of serum 1,3-β-D-gluan as biomarker for invasive fungal infection through meta-analysis.

Methods

The electronic databases of Medline, Cochrane, Embase, Web of Science, OVID and CNKI were systematic searched to identified the case-control or Cohort studies relevant to diagnostic efficacy of serum 1,3-β-D-glucan for invasive fungal infection. The data of true positive (tp), false positive (fp), false negative (fn) and true negative (tn) patients number were extracted from each of the original included studies. The diagnostic sensitivity, specificity and systematic receiver operating characteristic (SROC) curve were calculated and pooled through random or fixed effect method. The publication bias was evaluated by the Deek's funnel plot.

Results

Thirty-seven relevant studies were fulfilled the inclusion criteria and included in our present meta-analysis. The combined sensitivity, specificity, positive likely hood ratio (+lr), negative likely hood ratio (-lr) and diagnostic odds ratio(dor) for 1,3-β-D-glucan in diagnosis of invasive fungal infectionwere 0.83 (95%CI:0.38-0.61), 0.81 (95%CI:0.80-0.82), 5.13 (95%CI:3.98-6.62), 0.23 (95%CI:0.18-0.30), and 29.68 (95%CI:18.94-46.52) respectively. The pooled area under the ROC curve (AUC) was 0.91.The Deek's funnel plot asymmetry test showed there was no publication bias for 1,3-β-D-glucan in diagnosis of invasive fungal infection of the included 37 studies.

Conclusion

Serum 1,3-β-D-glucan assay was a promising biomarker for invasive fungal infection diagnosis.

Role of serum (1,3)-β-d-glucan assay in early diagnosis of invasive fungal infections in a neonatal intensive care unit

OBJECTIVES

To study the microbiological pattern of late onset neonatal sepsis cultures and to assess the diagnostic performance of serum (1,3)-β-d-glucan level for early diagnosis of invasive fungemia in high-risk infants admitted to a neonatal intensive care unit.

METHODS

A prospective multicenter clinical trial conducted on infants at high risk for invasive fungal infections, with suspected late onset sepsis, admitted to a neonatal intensive care unit at Mansoura University Children's Hospital and Mansoura General Hospital between March 2014 and February 2016.

RESULTS

A total of 77 newborn infants with high risk of invasive fungal infection were classified based on blood culture into three groups: no fungemia (41 neonates with proven bacterial sepsis), suspected fungemia (25 neonates with negative blood culture), and definite fungemia group (11 neonates with culture-proven Candida). The growing organisms were Klebsiella spp. (14/54); Escherichia coli (12/54); Staphylococcus spp. (12/54; coagulase-negative Staphylococcus [9/54]; Staphylococcus aureus [3/54]); Pseudomonas aerouginosa (3/54); and Proteus spp. (2/54). Moreover, 11/54 presented Candida. Serum (1,3)-β-d-glucan concentration was significantly lower in the no fungemia group when compared with the definite fungemia group. The best cut-off value of (1,3)-β-d-glucan was 99pg/mL with sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of 63.6%, 95.1%, 77.8%, 90.7%, and 88.5%, respectively.

CONCLUSION

(1,3)-β-d-glucan assay has a limited sensitivity with excellent specificity and negative predictive value, which allow its use as an aid in exclusion of invasive neonatal fungal infection. Accurate diagnosis and therapeutic decisions should be based on combining (1,3)-β-d-glucan assay with other clinical, radiological, and microbiological findings.

Detection of invasive pulmonary aspergillosis in critically ill patients by combined use of conventional culture, galactomannan, 1-3-beta-D-glucan and Aspergillus specific nested polymerase chain reaction in a prospective pilot study

Invasive pulmonary aspergillosis (IPA) is an emerging and life-threatening infectious disease in patients admitted to the intensive care unit (ICU). Most diagnostic studies are conducted in hematological patients and results cannot readily be transferred to ICU patients lacking classical host factors. In a multicenter, prospective clinical trial including 44 ICU patients, hematological (n = 14) and non-hematological patients (n = 30), concurrent serum and bronchoalveolar lavage (BAL) samples were analyzed by conventional culture, galactomannan (GM), 1-3-beta-D-glucan (BDG) as well as an Aspergillus specific nested polymerase chain reaction (PCR). Nine patients (20%) had putative IPA according to AspICU classification. GM and PCR showed superior performance in BAL with sensitivity/specificity of 56%/94% and 44%/94% compared to 33%/97% and 11%/94% in serum. Despite better sensitivity of 89%, BDG showed poor specificity of only 31% (BAL) and 26% (serum). Combination of GM and PCR (BAL) with BDG (serum) resulted in 100% sensitivity, but also reduced specificity to 23%. Whereas mean GM levels were significantly higher in hematological patients BDG and PCR did not differ between hematological and non-hematological patients. Under present clinical conditions test combinations integrating both BAL and blood samples are advantageous. BDG might best serve as possible indicator for ruling out IPA.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT01695499. First posted: September 28, 2012, last update posted: May 8, 2017.

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

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

(1, 3)-β-D-glucan assay for diagnosing invasive fungal infections in critically ill patients with hematological malignancies

Invasive fungal infections (IFIs) are life-threatening complications of hematological malignancies that must be diagnosed early to allow effective treatment. Few data are available on the performance of serum (1–3)-β-D-glucan (BG) assays for diagnosing IFI in patients with hematological malignancies admitted to the intensive care unit (ICU). In this study, 737 consecutive patients with hematological malignancies admitted to 17 ICUs routinely underwent a BG assay at ICU admission. IFIs were diagnosed using standard criteria applied by three independent specialists. Among the 737 patients, 439 (60%) required mechanical ventilation and 273 (37%) died before hospital discharge. Factors known to alter BG concentrations were identified in most patients. IFIs were documented in 78 (10.6%) patients (invasive pulmonary aspergillosis, n = 54; Pneumocystis jirovecii pneumonia, n = 13; candidemia, n = 13; and fusarium infections, n = 3). BG concentrations (pg/mL) were higher in patients with than without IFI (144 (77–510) vs. 50 (30–125), < 0.0001). With 80 pg/mL as the cutoff, sensitivity was 72%, specificity 65%, and area-under-the-curve 0.74 (0.68–0.79). Assuming a prevalence of 10%, the negative and positive predictive values were 94% and 21%. By multivariable analysis, factors independently associated with BG > 80 pg/mL were IFI, admission SOFA score, autologous bone-marrow or hematopoietic stem-cell transplantation, and microbiologically documented bacterial infection. In conclusion, in unselected critically ill hematology patients with factors known to affect serum BG, this biomarker showed only moderate diagnostic performance and rarely detected IFI. However, the negative predictive value was high. Studies are needed to assess whether a negative BG test indicates that antifungal de-escalation is safe.

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 prospective study of fungal biomarkers to improve management of invasive fungal diseases in a mixed specialty critical care unit

PURPOSE

The diagnosis of invasive fungal diseases (IFD) in critical care patients (CrCP) is difficult. The study investigated the performance of a set of biomarkers for diagnosis of IFD in a mixed specialty critical care unit (CrCU).

METHODS

A prospective observational study in patients receiving critical care for ≥7days was performed. Serum samples were tested for the presence of: (1-3) - β-d-glucan (BDG), galactomannan (GM), and Aspergillus fumigatus DNA. GM antigen detection was also performed on bronchoalveolar lavage (BAL) samples. The patients were classified using published definitions for IFD and a diagnostic algorithm for invasive pulmonary aspergillosis. Performance parameters of the assays were determined.

RESULTS

In patients with proven and probable IFD, the sensitivity, specificity, PPV and NPV of a single positive BDG were 63%, 83%, 65% and 83% respectively. Specificity increased to 86% with 2 consecutive positive results. The mean BDG value of patients with proven and probable IFD was significantly higher compared to those with fungal colonization and no IFD (p value<0.0001).

CONCLUSION

New diagnostic criteria which incorporate these biomarkers, in particular BDG, and host factors unique to critical care patients should enhance diagnosis of IFD and positively impact antifungal stewardship programs.

Challenges in microbiological diagnosis of invasive Aspergillus infections

Invasive aspergillosis (IA) has been increasingly reported in populations other than the historical hematology patients and there are new questions about the performance of microbiological tools. Microscopy and culture have been completed by biomarkers, either antigens or DNA, and in blood or respiratory specimens or both. First studied in hematology, the antigen galactomannan performance in serum is low in other patient populations where the pathophysiology of the infection can be different and the prevalence of IA is much lower. DNA detection with polymerase chain reaction (PCR) in blood or serum (or both) has reached a certain level of acceptance thanks to consensus methods based on real-time quantitative PCR (qPCR). When used on respiratory specimens, galactomannan and qPCR depend on standardization of the sampling and the diverse mycological procedures. Thus, culture remains the main diagnostic criterion in critically ill patients. The current trend toward more effective anti-mold prophylaxis in hematology hampers the yield of a screening strategy, as is usually performed in hematology. Therefore, circulating biomarkers as confirmatory tests should be considered and their performance should be reappraised in each new setting. The use of azole prophylaxis also raises the issue of selecting azole-resistance Aspergillus fumigatus isolates. Ideally, the biomarkers will be more efficient when individual genetic risks of IA are defined. Culture, though not standardized, remains a key element for the diagnosis of IA and has the advantage to easily detect molds other than A. fumigatus. It is still unclear whether next-generation sequencing will replace culture in the future.

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.

Diagnostic performance of 1,3-beta-D-glucan serum screening in patients receiving hematopoietic stem cell transplantation

BACKGROUND

The polysaccharide cell wall component, 1,3-beta-D-glucan (BDG), is used as a serum biomarker for invasive fungal infection (IFI). Patients receiving hematopoietic stem cell transplantation (HSCT) are considered a highly vulnerable group for IFI development. We evaluated the diagnostic performance of serum BDG screening in HSCT recipients.

METHODS

HSCT recipients were prospectively enrolled in this study between September 2014 and August 2015. Routine serum BDG screening was performed 2-3 times weekly by using the Fungitell(®) assay. All samples were classified according to the 2008 EORTC/MSG criteria, with serum BDG results not being considered for classification. The diagnostic performance of BDG testing for IFI was calculated. BDG values ≥80 pg/mL were considered positive.

RESULTS

A total of 308 serum samples were collected in 45 patients. The majority of 172 samples (55.8%) were obtained at the early phase (within 30 days) after allogeneic HSCT. BDG levels were significantly higher in 16 possible/probable IFI samples when compared to no evidence for IFI samples (median 170 pg/mL, interquartile range [IQR] 100-274 pg/mL vs. median 15 pg/mL, IQR 15-15 pg/mL; P < 0.001, Mann-Whitney U-test). Diagnostic performance of serum BDG screening for possible IFI/probable invasive pulmonary aspergillosis vs. no evidence for IFI was as follows: sensitivity 81%, specificity 98%, positive predictive value 65%, negative predictive value (NPV) 99%, and diagnostic odds ratio 176 (95% confidence interval 41-761).

CONCLUSIONS

Our data suggest that serum BDG testing in HSCT patients may be highly specific and associated with a very high NPV of >99%. Therefore, serum BDG may be a helpful tool to rule out IFI in HSCT patients.

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.

Detection of a Serum Siderophore by LC-MS/MS as a Potential Biomarker of Invasive Aspergillosis

Invasive aspergillosis (IA) is a life-threatening systemic mycosis caused primarily by Aspergillus fumigatus. Early diagnosis of IA is based, in part, on an immunoassay for circulating fungal cell wall carbohydrate, galactomannan (GM). However, a wide range of sensitivity and specificity rates have been reported for the GM test across various patient populations. To obtain iron in vivo, A. fumigatus secretes the siderophore, N,N',N"-triacetylfusarinine C (TAFC) and we hypothesize that TAFC may represent a possible biomarker for early detection of IA. We developed an ultra performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) method for TAFC analysis from serum, and measured TAFC in serum samples collected from patients at risk for IA. The method showed lower and upper limits of quantitation (LOQ) of 5 ng/ml and 750 ng/ml, respectively, and complete TAFC recovery from spiked serum. As proof of concept, we evaluated 76 serum samples from 58 patients with suspected IA that were investigated for the presence of GM. Fourteen serum samples obtained from 11 patients diagnosed with probable or proven IA were also analyzed for the presence of TAFC. Control sera (n = 16) were analyzed to establish a TAFC cut-off value (≥6 ng/ml). Of the 36 GM-positive samples (≥0.5 GM index) from suspected IA patients, TAFC was considered positive in 25 (69%). TAFC was also found in 28 additional GM-negative samples. TAFC was detected in 4 of the 14 samples (28%) from patients with proven/probable aspergillosis. Log-transformed TAFC and GM values from patients with proven/probable IA, healthy individuals and SLE patients showed a significant correlation with a Pearson r value of 0.77. In summary, we have developed a method for the detection of TAFC in serum that revealed this fungal product in the sera of patients at risk for invasive aspergillosis. A prospective study is warranted to determine whether this method provides improved early detection of IA.

Platelet parameters and (1, 3)-β-D-glucan as a diagnostic and prognostic marker of invasive fungal disease in preterm infants

The diagnosis of neonatal invasive fungal disease (IFD) is difficult and often delayed. The platelet parameters and (1, 3)-β-D-Glucan (BG) may be useful for diagnosing IFD, but their diagnostic performance are not well characterized in neonates. We studied 63 preterm infants with IFD, 160 preterm infants without sepsis (preterm control), and 41 preterm infants with bacterial sepsis. Platelet parameters at the first day of onset of IFD and at the fourteenth day after antifungal treatment were evaluated. Serum BG was measured. Platelet count (PC), plateletcrit (PCT), and platelet distribution width (PDW) values were significantly lower, and mean platelet volume (MPV) values significantly higher in the IFD versus preterm control infants. PC and PCT values were much lower in infants with IFD versus bacterial sepsis, and there were significant differences in BG value between the two groups. After 14 days of antifungal treatment, significant elevations in PC, PCT, PDW and reductions in MPV levels in IFD group were observed. Receiver operating characteristic (ROC) curves showed that PC and PCT were strong predictors of IFD. The PC and PCT cut-offs for predicting IFD were 119.5 (sensitivity 78%, specificity 95%) and 0.21 (sensitivity 83%, specificity 85%), respectively. There were significant differences in PC and PCT levels between deceased and survived patients. The PC and PCT cut-offs for predicting deceased IFD were 39 (sensitivity 62%, specificity 86%) and 0.04 (sensitivity 50%, specificity 95%), respectively. The sensitivity in diagnosing IFD by a BG cutoff of ≥10pg/ml was 68.3% and specificity was 75.6%. PC and PCT levels in the BG ≥400 pg/ml group were significantly lower compared to the BG<400 pg/ml group. Platelet parameters and BG could be useful biomarkers for the diagnosis and prognosis of neonatal IFD.

How to interpret serum levels of beta-glucan for the diagnosis of invasive fungal infections in adult high-risk hematology patients: optimal cut-off levels and confounding factors

Detection of the fungal cell wall component beta-glucan (BG) in serum is increasingly used to diagnose invasive fungal infections (IFI), but its optimal use in hematology patients with high risk of IFI is not well defined. We retrospectively analyzed the diagnostic accuracy, optimal cut-off level, and potential confounding factors of BG reactivity. The inclusion criteria were: adult patients with hematologic disease who were admitted to the hematology ward during the 2-year study period and who had two or more consecutive BG assays performed. In total, 127 patients were enrolled. Thirteen patients with proven or probable IFI, as defined by the 2008 European Organization for Research and Treatment of Cancer/Mycoses Study Group (EORTC/MSG) criteria, were identified. Receiver operating characteristic (ROC) curve analysis showed a high overall diagnostic performance (area under the ROC curve = 0.98) and suggested an optimal cut-off level of 158 pg/ml, with a sensitivity and a specificity of 92 % and 96 %, respectively. Multiway analysis of variance indicated that treatment with pegylated asparaginase (p < 0.001), admission to the intensive care unit (ICU; p = 0.0007), and treatment with albumin, plasma, or coagulation factors (p = 0.01) are potential confounding factors of BG reactivity. We propose that a higher cut-off level than that recommended by the manufacturer should be used to monitor adult hematology patients at high risk for IFI. Our results also suggest that elevated BG levels in patients treated with pegylated asparaginase, albumin, plasma, or coagulation factors, or those admitted to the ICU should be interpreted with caution.

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.

Performance of galactomannan, beta-d-glucan, Aspergillus lateral-flow device, conventional culture, and PCR tests with bronchoalveolar lavage fluid for diagnosis of invasive pulmonary aspergillosis

Galactomannan detection in bronchoalveolar lavage (BAL) fluid samples (GM test) is currently considered the gold standard test for diagnosing invasive pulmonary aspergillosis (IPA). The limitations, however, are the various turnaround times and availability of testing. We compared the performance of GM testing with that of conventional culture, an Aspergillus lateral-flow-device (LFD) test, a beta-d-glucan (BDG) test, and an Aspergillus PCR assay by using BAL fluid samples from immunocompromised patients. A total of 78 BAL fluid samples from 78 patients at risk for IPA (74 samples from Graz and 4 from Mannheim) collected between December 2012 and May 2013 at two university hospitals in Austria and Germany were included. Three patients had proven IPA, 14 probable IPA, and 17 possible IPA, and 44 patients had no IPA. The diagnostic accuracies of the different methods for probable/proven IPA were evaluated. The diagnostic odds ratios were the highest for the GM, PCR, and LFD tests. The sensitivities for the four methods (except culture) were between 70 and 88%. The combination of the GM (cutoff optical density index [ODI], >1.0) and LFD tests increased the sensitivity to 94%, while the combination of the GM test (>1.0) and PCR resulted in 100% sensitivity (specificity for probable/proven IPA, 95 to 98%). The performance of conventional culture was limited by low sensitivity, while that of the BDG test was limited by low specificity. We evaluated established and novel diagnostic methods for IPA and found that the Aspergillus PCR, LFD, and GM tests were the most useful methods for diagnosing the disease by using BAL fluid samples. In particular, the combination of the GM test and PCR or, if PCR is not available, the LFD test, allows for sensitive and specific diagnosis of IPA.

β-D-glucan testing is important for diagnosis of invasive fungal infections

Invasive fungal infections are a significant cause of morbidity and mortality in patients who receive immunosuppressive therapy, such as solid organ and hematopoietic stem cell transplant (HSCT) recipients. Many of the fungi associated with these infections are angioinvasive and are best diagnosed by visualizing the organism in or culturing the organism from deep tissue. However, obtaining such tissue often requires an invasive procedure. Many HSCT recipients are thrombocytopenic, making such procedure too risky because of potential bleeding complications. Additionally, positive blood cultures are rare for patients with angioinvasive fungal infections, making this diagnostic strategy of little value. Undiagnosed fungal infections in these patient populations are a significant cause of mortality. Prophylactic use of antifungal agents, such as the echinocandins, during periods of neutropenia or graft-versus-host disease may prevent some fungal infections but increase the risk for others. Detection of fungal antigens in body fluids, including cryptococcus capsular polysaccharide, histoplasma antigen, galactomannan, and β-d-glucan, is viewed as being clinically useful for at least the presumptive diagnosis of invasive fungal infections. β-d-Glucan is an attractive antigen in that it is found in a broad range of fungal agents, including the commonly encountered agents Candida spp., Aspergillus spp., and Pneumocystis jirovecii. Cross-reactions with certain hemodialysis filters, beta-lactam antimicrobials, and immunoglobulins, which raise concerns about false-positive tests, have also been described. As a result, the use of this testing must be closely monitored. In this point-counterpoint, we have asked Elitza Theel, who directs the Infectious Disease Serology Laboratory at the Mayo Clinic, to address why she believes that this test has value in the diagnosis of invasive fungal infections. We have asked Christopher Doern, Director of Clinical Microbiology at Children's Medical Center of Dallas, why he questions the clinical value of β-d-glucan testing.

Infection in neutropenic patients with cancer

Neutropenic fever sepsis syndromes are common among patients with cancer who are receiving intensive cytotoxic systemic therapy. Recognition of the syndromes and timely initial antibacterial therapy is critical for survival and treatment success. Outcomes are linked to myeloid reconstitution and recovery from neutropenia, control of active comorbidities, and appropriate treatment of the infections that underlie the sepsis syndrome. Hematologists and oncologists must be clear about the prognosis and treatment goals to work effectively with critical care physicians toward the best outcomes for patients with cancer who develop neutropenic sepsis syndromes.

ESCMID* guideline for the diagnosis and management of Candida diseases 2012: adults with haematological malignancies and after haematopoietic stem cell transplantation (HCT)

Fungal diseases still play a major role in morbidity and mortality in patients with haematological malignancies, including those undergoing haematopoietic stem cell transplantation. Although Aspergillus and other filamentous fungal diseases remain a major concern, Candida infections are still a major cause of mortality. This part of the ESCMID guidelines focuses on this patient population and reviews pertaining to prophylaxis, empirical/pre-emptive and targeted therapy of Candida diseases. Anti-Candida prophylaxis is only recommended for patients receiving allogeneic stem cell transplantation. The authors recognize that the recommendations would have most likely been different if the purpose would have been prevention of all fungal infections (e.g. aspergillosis). In targeted treatment of candidaemia, recommendations for treatment are available for all echinocandins, that is anidulafungin (AI), caspofungin (AI) and micafungin (AI), although a warning for resistance is expressed. Liposomal amphotericin B received a BI recommendation due to higher number of reported adverse events in the trials. Amphotericin B deoxycholate should not be used (DII); and fluconazole was rated CI because of a change in epidemiology in some areas in Europe. Removal of central venous catheters is recommended during candidaemia but if catheter retention is a clinical necessity, treatment with an echinocandin is an option (CII(t) ). In chronic disseminated candidiasis therapy, recommendations are liposomal amphotericin B for 8 weeks (AIII), fluconazole for >3 months or other azoles (BIII). Granulocyte transfusions are only an option in desperate cases of patients with Candida disease and neutropenia (CIII).

Invasive fungal infections in patients with cancer in the Intensive Care Unit

Invasive fungal infections (IFIs) have emerged as a major cause of morbidity and mortality amongst critically ill patients. Cancer patients admitted to the Intensive Care Unit (ICU) have multiple risk factors for IFIs. The vast majority of IFIs in the ICU are due to Candida spp. The incidence of invasive candidiasis (IC) has increased over recent decades, especially in the ICU. A shift in the distribution of Candida spp. from Candida albicans to non-albicans Candida spp. has been observed both in ICUs and oncology units in the last two decades. Timely diagnosis of IC remains a challenge despite the introduction of new microbiology techniques. Delayed initiation of antifungal therapy is associated with increased mortality. Therefore, prediction rules have been developed and validated prospectively in order to identify those ICU patients at high risk for IC and likely to benefit from early treatment. These rules, however, have not been validated in cancer patients. Similarly, major clinical studies on the efficacy of newer antifungals typically do not include cancer patients. Despite the introduction of more potent and less toxic antifungals, mortality from IFIs amongst cancer patients remains high. In recent years, aspergillosis and mucormycosis have also emerged as significant causes of morbidity and mortality amongst ICU patients with haematological cancer.