ECIL recommendations for the use of biological markers for the diagnosis of invasive fungal diseases in leukemic patients and hematopoietic SCT recipients

Evaluation of a genus-specific ELISA and a commercial Aspergillus Western blot IgG® immunoblot kit for the diagnosis of aspergillosis in common bottlenose dolphins (Tursiops truncatus)

Aspergillosis is a fungal infection with high mortality and morbidity rates. As in humans, its definitive diagnosis is difficult in animals, and thus new laboratory tools are required to overcome the diagnostic limitations due to low specificity and lack of standardization. In this study of common bottlenose dolphins (Tursiops truncatus), we evaluated the diagnostic performance of a new commercial immunoblot kit that had been initially developed for the serologic diagnosis of chronic aspergillosis in humans. Using this in a quantitative approach, we first established its positive cutoff within an observation cohort of 32 serum samples from dolphins with "proven" or "probable" diagnosis of aspergillosis and 55 negative controls. A novel enzyme-linked immunosorbent assay (ELISA) test was also developed for detecting anti-Aspergillus antibodies, and results were compared between the two assays. Overall, the diagnostic performance of immunoblot and ELISA were strongly correlated (P < .0001). The former showed lower sensitivity (65.6% versus 90.6%), but higher specificity (92.7% vs. 69.1%), with no cross-reaction with other fungal infections caused by miscellaneous non-Aspergillus genera. When assessing their use in a validation cohort, the immunoblot kit and the ELISA enabled positive diagnosis before mycological cultures in 42.9% and 33.3% subjects addressed for suspicion of aspergillosis, respectively. There was also significant impact of antifungal treatment on the results of the two tests (P < .05). In all, these new serological methods show promise in aiding in the diagnosis of aspergillosis in dolphins, and illustrate the opportunity to adapt commercial reagents directed for human diagnostics to detect similar changes in other animals.

Comparative Analysis of the Wako β-Glucan Test and the Fungitell Assay for Diagnosis of Candidemia and Pneumocystis jirovecii Pneumonia

(1→3)-β-d-Glucan (BDG) is a biomarker for invasive fungal disease. Until now, all BDG data in the Western Hemisphere were obtained using the Fungitell assay (FA). How it compares to the Wako β-glucan test (GT), which was recently launched in Europe, is largely unknown. We conducted a case-control study to compare the two assays in serum samples from 120 candidemia and 63 Pneumocystis jirovecii pneumonia (PCP) patients. Two hundred patients with bacteremia or negative blood cultures served as candidemia control group. In patients with candidemia the median BDG values of the FA and the GT were 351 and 8.4 pg/ml, respectively. With both assays, the BDG levels in candidemia were significantly higher than those measured in the control group (P < 0.001). The sensitivity, specificity, and positive and negative predictive values for the diagnosis of candidemia were 86.7%, 85.0%, 6.0%, and 99.8% for the FA and 42.5%, 98.0%, 19.0%, and 99.4% for the GT, respectively. In PCP patients the median BDG values of the FA and the GT were 963 and 57.7 pg/ml, respectively. The sensitivities for PCP diagnosis were 100% for the FA and 88.9% for the GT. In practical terms, the GT proved to be robust and applicable for testing single samples, whereas for economic reasons the FA required the samples to be tested in batch. The sensitivity of the FA is superior to that of the GT. However, the GT is a valuable alternative to the FA, especially for patients with suspected PCP and in laboratories with low sample throughput.

Translational proteomic study to address host protein changes during aspergillosis

Aspergillosis is a fungal disease due to Aspergillus molds that can affect both humans and animals. As routine diagnosis remains difficult, improvement of basic knowledge with respect to its pathophysiology is critical to search for new biomarkers of infection and new therapeutic targets. Large-scale proteomics allows assessment of protein changes during various disease processes. In the present study, mass spectrometry iTRAQ® (isobaric tags for relative and absolute quantitation) protocol was used for direct identification and relative quantitation of host proteins in diseased fluids and tissues collected from an experimental rat model challenged with Aspergillus, as well as in blood obtained from naturally-infected penguins. In all, mass spectrometry analysis revealed that proteome during aspergillosis was mostly represented by proteins that usually express role in metabolic processes and biological process regulation. Ten and 17 proteins were significantly ≥4.0-fold overrepresented in blood of Aspergillus-diseased rats and penguins, respectively, while five and 39 were negatively ≥4.0-fold depleted within the same samples. In rat lungs, 33 proteins were identified with positive or negative relative changes versus controls and were quite different from those identified in the blood. Except for some zinc finger proteins, kinases, and histone transferases, and while three pathways were common (Wnt, cadherin and FGF), great inter-species variabilities were observed regarding the identity of the differentially-represented proteins. Thus, this finding confirmed how difficult it is to define a unique biomarker of infection. iTRAQ® protocol appears as a convenient proteomic tool that is greatly suited to ex vivo exploratory studies and should be considered as preliminary step before validation of new diagnostic markers and new therapeutic targets in humans.

Evaluation of the (1,3)-β-D-glucan assay for the diagnosis of neonatal invasive yeast infections

Most newborns in the neonatal intensive care unit (NICU) are premature and at risk of invasive fungal infections (IFIs). Invasive yeast infections (IYIs) are the most common fungal infections in this population. These infections are difficult to diagnose because symptoms are nonspecific, and the sensitivity of blood cultures is low. The serum (1,3)-β-D-glucan (BDG) assay provides a reliable marker for the diagnosis of IFIs in adults with haematological malignancies. We assessed the diagnostic performance of this test in neonatal IYIs and its contribution to the monitoring of antifungal treatment. A retrospective study was performed in the NICU of the French University Hospital of Amiens from February 2012 to February 2014. Forty-seven neonates (33 males, 14 females) with a median gestational age of 30 weeks (IQR: 27-31) and median birth weight of 1200 g (IQR: 968-1700) were included and divided into three groups: 21 control neonates (CTRL), 20 neonates with probable IYI (PB), and six with proven IYI (PV). Median BDG levels were significantly higher in the global IYI group (PB + PV): 149 pg/ml (IQR: 85-364) vs. CTRL group: 39 pg/ml (IQR: 20-94) (P < .001). The optimal cut-off was 106 pg/ml (sensitivity 61.5%; specificity 81%). BDG levels decreased with antifungal treatment. BDG was detectable in cerebrospinal fluid, but the interest of this for diagnostic purposes remains unclear. Our results suggest that the BDG assay may be useful for the early identification of IYIs in neonates and for monitoring antifungal therapy efficacy.

Performance of serum (1,3)-ß-d-glucan screening for the diagnosis of invasive aspergillosis in neutropenic patients with haematological malignancies

We report our experience with the use of (1,3)-ß-d-glucan (BDG) screening for the diagnosis of invasive aspergillosis (IA) in neutropenic patients with haematological malignancies. The performance of BDG screening was assessed retrospectively in per patient and per sample analyses. Overall, 20 among 167 patients developed IA (12%). In the per patient analysis, BDG showed 60% sensitivity and 78% specificity when the criterion for positivity was the presence of at least one BDG value ≥80 pg/mL. For 2 consecutive positive results, sensitivity decreased to 40%, while specificity increased to 93% and was similar to that of a positive galactomannan (GM; 90%). The highest specificity (97%) was observed for combined positivity of at least one BDG and at least one GM. In the per sample analysis, the specificity of BDG was 100% in the best scenario, 96% in the median scenario and 89% in the worst scenario. BDG became positive before GM in 33% of IA patients with both markers positive (n = 12). Despite good specificity for 2 consecutive positive results, the BDG test offered unsatisfactory performance for the diagnosis of IA due to low sensitivity. The combination of BDG and GM showed the potential for increasing specificity.

Risk Adapted Management of Febrile Neutrepenia and Early Cessation of Empirical Antibiotherapy in Hematopoietic Stem Cell Transplantation Setting

Background:

Haematopoietic stem cell transplantation is a curative treatment option for many haematological disorders. Infection following haematopoietic stem cell transplantation is one of the major causes of mortality.

Aims:

To investigate the outcomes of early cessation of empirical antibiotic treatment per protocol in febrile neutropenia patients who have undergone haematopoietic stem cell transplantation at our clinic.

Study Design:

Descriptive study.

Methods:

The present study retrospectively evaluated febrile neutropenia attacks in haematopoietic stem cell transplantation recipients during the period June 2014 - January 2015 at our haematopoietic stem cell transplantation clinic.

Results:

A total of 72 febrile neutropenia attacks were evaluated in 53 patients. In 46 febrile neutropenia attacks, microbiologic cultures revealed positive results. In culture-positive febrile neutropenia episodes a single bacterium was isolated in 32 cases and multiple strains were isolated in 14. In 15 patients, empirical antibiotic therapy was discontinued after 72 hours. These patients were clinically stable, without evident focus of infection and had negative culture results. Only 4 recurrent episodes were observed (27%) after cessation of antibiotherapy. No patient died as a result of recurrent infection. The 30-day and 100-day post-transplantation mortality rates of patients with febrile neutropenia episodes were 11.3% (6/53) and 3.8% (2/53), respectively. Infection-related 30-day and 100-day mortality rates were 7.5% (4/53) and 0% (0/53), respectively.

Conclusion:

The main message of our study is that early cessation of empirical antibiotherapy seems to be feasible in eligible patients without increasing febrile neutropenia mortality rates.

Utility of posaconazole therapeutic drug monitoring and assessment of plasma concentration threshold for effective prophylaxis of invasive fungal infections: a meta-analysis with trial sequential analysis

Background

Posaconazole therapeutic drug monitoring (TDM) is increasingly used in clinical practice. However, the utility of posaconazole TDM and the target of posaconazole plasma concentration for clinical successful prophylaxis remain uncertain and controversial. The aim of this study was to evaluate posaconazole exposure-response relationship and determine an optimum posaconazole concentration for prophylaxis against invasive fungal infections (IFIs).

Methods

Bibliographic databases were searched (from inception to September 2017) to select studies including the clinical outcomes below and above concentration cut-off value of 0.5 mg/L and 0.7 mg/L. The reliability of the results were evaluated with trial sequential analysis (TSA).

Results

Twenty-eight studies with 1930 patients included were analyzed. The results of our pooled analysis demonstrated that patients with posaconazole plasma concentrations over 0.5 mg/L were twice more likely to achieve successful responses compared with those with lower concentrations (odds ratio, OR = 1.98, 95% confidence interval, CI 1.09–3.58, P = 0.02) while the threshold, 0.7 mg/L showed no significant difference (OR = 1.84, 95% CI 0.94–3.63, P = 0.08). The TSA results showed that there was sufficient information to support these findings.

Conclusions

An optimal posaconazole concentration target of 0.5 mg/L is suggested to ensure the clinical prophylactic efficacy and may help reduce the dosage and dose-dependent toxicity comparing with the target of 0.7 mg/L.

Electronic supplementary material

The online version of this article (10.1186/s12879-018-3055-3) contains supplementary material, which is available to authorized users.

Infectious complications after hematopoietic stem cell transplantation: current status and future perspectives in Korea

Hematopoietic stem cell transplantation (HSCT) is a treatment for hematologic malignancies, immune deficiencies, or genetic diseases, ect. Recently, the number of HSCTs performed in Korea has increased and the outcomes have improved. However, infectious complications account for most of the morbidity and mortality after HSCT. Post-HSCT infectious complications are usually classified according to the time after HSCT: pre-engraftment, immediate post-engraftment, and late post-engraftment period. In addition, the types and risk factors of infectious complications differ according to the stem cell source, donor type, conditioning intensity, region, prophylaxis strategy, and comorbidities, such as graft-versushost disease and invasive fungal infection. In this review, we summarize infectious complications after HSCT, focusing on the Korean perspectives.

[Invasive pulmonary aspergillosis]

INTRODUCTION

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

BACKGROUND

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

OUTLOOK

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

CONCLUSIONS

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

Cryptococcal Pleuritis Presenting with Lymphocyte-predominant and High Levels of Adenosine Deaminase in Pleural Effusions Coincident with Pulmonary Tuberculosis

Co-infection with cryptococcus and tuberculosis has rarely been reported. We herein report a case of an 80-year-old man with cryptococcal pleuritis concurrent with pulmonary tuberculosis. He was admitted for progression of left pleural effusion and consolidation in the left upper lobe. Culture for Mycobacterium tuberculosis was positive in sputum, and analyses of pleural effusion revealed lymphocyte-predominant high levels of adenosine deaminase (ADA). Medical thoracoscopy revealed massive infiltration of Cryptococcus neoformans in pleura without granuloma. This is the first case report of cryptococcal pleuritis coincident with pulmonary tuberculosis. Cryptococcal pleuritis should be ruled out when the adenosine deaminase levels are elevated in pleural effusion.

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

Background

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

Methods

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

Results

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

Conclusion

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

Primary antifungal prophylaxis: decrease of invasive fungal disease incidence and reduction of risk factors in haematological patients in a 5-year retrospective study

BACKGROUND

Invasive fungal disease (IFD) is a major cause of morbidity and mortality in patients with haematological malignancies.

AIM

To evaluate the efficacy and rationality of primary antifungal prophylaxis (PAP) in a 5-year real-life setting and choose an appropriate PAP strategy.

METHODS

Clinical data of patients were retrospectively reviewed and IFD was diagnosed using the revised diagnostic criteria. The efficacy of PAP and the risk factors for IFD, especially the rationality of PAP, were evaluated.

RESULTS

Of the 1340 patients enrolled, 749 patients received PAP (55.9%), and IFD occurred in 157 patients: 51 (6.8%) in the PAP group and 106 (17.9%) in the non-PAP group (P = 0.000). The IFD-related mortality was 10.1 and 29.7% in the PAP group and non-PAP group (P = 0.000) respectively. PAP was an independent protective factor for IFD (odds ratio = 0.183, 95% confidence interval: 0.122-0.274, P = 0.000) and could reduce the effect of risk factors, such as allogeneic haemopoietic stem cell transplantation, prolonged neutropenia and corticosteroid. The IFD incidence was not significantly different among different PAP regimens and PAP start time subgroups, and it was lowest (4.2%) when PAP started after a short period of neutropenia (1-10 days).

CONCLUSION

PAP is necessary and efficient to prevent IFD in haematological patients, and the real-life PAP strategy is reasonable. Different drugs can be chosen, and it is better to start PAP as soon as neutropenia begins.

Cryptococcal meningitis in apparently immunocompetent patients: association with idiopathic CD4+ lymphopenia

We present two cases of cryptococcal meningitis in people subsequently diagnosed with idiopathic CD4+ lymphopenia. Both presented with new onset headaches without sinister features and were sent home on multiple occasions from emergency departments. Cryptococcal meningitis in HIV-negative patients poses major diagnostic and management problems; the associated mortality is 9%-27%. We suggest performing blood and cerebrospinal fluid cryptococcal antigen tests in all people with lymphocytic meningitis.

(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.

Characteristics of culture-positive invasive pulmonary aspergillosis in patients with hematologic diseases: Comparison between Aspergillus fumigatus and non-fumigatus Aspergillus species

While the epidemiology and clinical differences of various Candida spp. has been relatively well-identified, data regarding invasive aspergillosis (IA) caused by different Aspergillus spp. are insufficient.We aimed to determine the epidemiology of culture-positive invasive pulmonary aspergillosis (IPA) and to compare the characteristics and outcomes of Aspergillus fumigatus IPA with those of non-fumigatus IPA in patients with hematologic diseases. All consecutive cases of IPA from 2011 to 2015 were reviewed retrospectively.There were 430 proven/probable IPA and 76 culture-positive proven/probable IPA. Excluding cases of multiple species of fungi or cases having difficulties in species-level identification, 41 A fumigatus and 22 non-fumigatus IPA (Aspergillus flavus [n = 11], Aspergillus niger [n = 6], and Aspergillus terreus [n = 5]) were compared. There were no significant differences in baseline characteristics between the 2 groups. However, disseminated IA was more common in non-fumigatus IPA (2.4% vs 18.2%; P = .046). Paranasal sinus (PNS) involvement was more common in non-fumigatus IPA. There was a trend towards higher peak serum galactomannan values in non-fumigatus IPA than in A fumigatus IPA group (median 1.33 [interquartile 0.98-3.29] vs 0.97 [0.66-1.97]; P = .084). Clinical response and mortality did not differ between groups.The culture-positive rate of proven/probable IPA was 17.7%, of which non-fumigatus Aspergillus accounted for about one-third. Disseminated IA, especially involving the PNS, was more frequent in non-fumigatus IPA than in A fumigatus IPA.

Fungal Pneumonia in Patients with Hematologic Malignancies and Hematopoietic Cell Transplantation

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

Use of 1,3-β-D-glucan in invasive fungal diseases in hematology patients

INTRODUCTION

Invasive fungal diseases (IFD) remain a leading cause of morbidity and mortality in hematology patients. Within a diagnostic-driven approach, the use of the serum (1,3)-ß-D-glucan (BDG) test represents a valid tool for the early diagnosis and treatment of IFD. Areas covered: The available literature on the use of BDG in hematology patients was systematically retrieved. Then, it was reviewed and discussed, to identify key issues pertaining to a clinically-oriented narrative presentation of the topic. Expert commentary: The use of BDG in hematology patients at risk for invasive aspergillosis (IA) is secondary to the use of galactomannan. However, since BDG is not specific for IA, it offers an advantage of diagnosing also other IFD, such as candidiasis and pneumocystosis. The limitations of BDG include high costs and lower sensitivity in hematology patients compared to other cohorts. The risk of false positive results is possibly lower in real life than in theory, since glucan-free equipment is available and modern dialysis membranes and blood products usually do not release BDG. Thus, in experienced hands and selected clinical situations, BDG is a useful diagnostic tool, particularly due to short turnover time to results and versatility in diagnosing different IFD.

Circulating Aspergillus fumigatus DNA Is Quantitatively Correlated to Galactomannan in Serum

The performance of antigen galactomannan (GM) for diagnosing invasive aspergillosis (IA) is hampered by the occurrence of false-positive results. Quantitative PCR has been proposed to improve the diagnosis of IA. Therefore, we analyzed the value of performing a PCR test to the GM-positive serum sample. Using a quantitative PCR assay specific for Aspergillus fumigatus 28S ribosomal DNA, we retrospectively tested 422 GM-positive (Platelia Bio-Rad kit) serum samples collected over 1 year from 147 patients. The cases were classified based on EORTC criteria as “proven,” “probable,” and “no–IA” before availability of the PCR results. After exclusion of 65 samples for non-reproducibility of GM positivity (n = 62) or PCR inhibition (n = 3), 75 (21.0%) of the remaining 357 samples were PCR-positive. GM and fungal DNA showed a significantly positive correlation (p < 0.0001, R² = 0.27, slope = 0.98 ± 0.19). At least one PCR-positive result was observed in 63.3% (31/49) of IA patients and in 13.2% (13/98) of non-IA patients (p < 0.0001). The PCR positivity was also associated with the presence of other microbiological criteria among the 44 patients with IA and complete mycological workup (p = 0.014), as well as a higher mortality rate at six months among the 135 patients with hematological conditions (p = 0.0198). Overall, we found a quantitative correlation between serum GM and circulating DNA with an increased likelihood of IA when both were positive. A PCR-positive result also supported a higher fungal load when GM was already positive. We advocate adding a PCR test for every confirmed GM-positive serum sample.

Diagnosis and treatment of community-acquired pneumonia in adults: 2016 clinical practice guidelines by the Chinese Thoracic Society, Chinese Medical Association

Community‐acquired pneumonia (CAP) in adults is an infectious disease with high morbidity in China and the rest of the world. With the changing pattern in the etiological profile of CAP and advances in medical techniques in diagnosis and treatment over time, Chinese Thoracic Society of Chinese Medical Association updated its CAP guideline in 2016 to address the standard management of CAP in Chinese adults. Extensive and comprehensive literature search was made to collect the data and evidence for experts to review and evaluate the level of evidence. Corresponding recommendations are provided appropriately based on the level of evidence. This updated guideline covers comprehensive topics on CAP, including aetiology, antimicrobial resistance profile, diagnosis, empirical and targeted treatments, adjunctive and supportive therapies, as well as prophylaxis. The recommendations may help clinicians manage CAP patients more effectively and efficiently. CAP in pediatric patients and immunocompromised adults is beyond the scope of this guideline. This guideline is only applicable for the immunocompetent CAP patients aged 18 years and older. The recommendations on selection of antimicrobial agents and the dosing regimens are not mandatory. The clinicians are recommended to prescribe and adjust antimicrobial therapies primarily based on their local etiological profile and results of susceptibility testing, with reference to this guideline.

Invasive candidiasis: future directions in non-culture based diagnosis

INTRODUCTION

Delayed initial antifungal therapy is associated with high mortality rates caused by invasive candida infections, since accurate detection of the opportunistic pathogenic yeast and its identification display a diagnostic challenge. diagnosis of candida infections relies on time-consuming methods such as blood cultures, serologic and histopathologic examination. to allow for fast detection and characterization of invasive candidiasis, there is a need to improve diagnostic tools. trends in diagnostics switch to non-culture-based methods, which allow specified diagnosis within significantly shorter periods of time in order to provide early and appropriate antifungal treatment. Areas covered: within this review comprise novel pathogen- and host-related testing methods, e.g. multiplex-PCR analyses, T2 magnetic resonance, fungus-specific DNA microarrays, microRNA characterization or analyses of IL-17 as biomarker for early detection of invasive candidiasis. Expert commentary: Early recognition and diagnosis of fungal infections is a key issue for improved patient management. As shown in this review, a broad range of novel molecular based tests for the detection and identification of Candida species is available. However, several assays are in-house assays and lack standardization, clinical validation as well as data on sensitivity and specificity. This underscores the need for the development of faster and more accurate diagnostic tests.

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

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

New therapeutic strategies for invasive aspergillosis in the era of azole resistance: how should the prevalence of azole resistance be defined?

Given reports showing a high prevalence of azole resistance in Aspergillus fumigatus, alternatives to azole therapy are discussed when a threshold of 10% of azole-resistant environmental isolates is reached. This raises the issue of calculation of this threshold, either on the prevalence of azole-resistant isolates as a whole or on the prevalence of azole-resistant cases in populations at risk of invasive aspergillosis (IA). For isolate evaluation, there are high disparities in routine microbiological procedures for the isolation of A. fumigatus and azole resistance detection. There are also huge differences between the microbiological work-up for diagnosing IA. Some centres rely on galactomannan detection alone without actively trying to culture appropriate samples, which affects reliability of the figures on the prevalence of resistance and thus the threshold of resistance. Moreover, reports from the laboratory could mix up figures from completely different patient populations: frequent azole-resistant isolates from pneumology patients and rare azole-resistant isolates from haematology patients. Therefore, to sum isolates from different specimens and different wards can lead to erroneous calculations for the restricted populations at risk of developing IA. In conclusion, assessing the incidence of azole resistance in A. fumigatus should be based on harmonized consensual microbiological methods and reports should be restricted to IA episodes in identified populations at risk of IA when the issue is to define an operational threshold for modifying recommendations.

New pharmacological opportunities for the treatment of invasive mould diseases

Recently, several randomized studies have been published that will shape treatment decisions in the prevention and management of invasive mould infections. Liposomal amphotericin B is an option for empirical or targeted treatment of invasive aspergillosis or mucormycosis, but for prophylaxis therapy, the triazole class now predominates. The triazole voriconazole is currently regarded as a drug of choice for the treatment of proven or probable invasive aspergillosis, and has shown significantly higher response rates than amphotericin B deoxycholate in this setting, with fewer severe drug-related adverse events. Isavuconazole, the newest triazole agent, offers the advantages of once-daily dosing, a wider spectrum of antifungal activity than voriconazole, predictable pharmacokinetics and fewer CYP enzyme-mediated drug interactions. A recent large randomized clinical trial showed mortality to be similar under isavuconazole or voriconazole in patients with invasive mould disease, with fewer drug-related adverse events in isavuconazole-treated patients. Another study has indicated that isavuconazole is also effective in mucormycosis infections but patient numbers were small and confirmation is awaited. Experimental studies combining different drug classes with antimould activity have been promising, but the clinical database is limited. A large randomized trial of combination therapy compared voriconazole plus the echinocandin anidulafungin versus voriconazole monotherapy in patients with invasive aspergillosis. Results showed the overall response rate to be similar, but combination therapy improved survival for the subpopulation of patients in whom the diagnosis was confirmed by serum and/or bronchoalveolar lavage fluid galactomannan positivity. This active field of research is likely to continue evolving rapidly in the coming years.

The current management landscape: aspergillosis

Diagnosing invasive aspergillosis (IA) has long been challenging due to the inability to culture the causal Aspergillus agent from blood or other body fluids. This shortcoming has fuelled an interest in non-culture-based diagnostic techniques such as the detection of galactomannan (GM) in blood and bronchoalveolar lavage fluid, the detection of 1,3-β-d-glucan (BDG) in blood and the detection of Aspergillus DNA by PCR-based techniques. Past decades have witnessed important improvements in our understanding of the strengths and limitations of antigen assays and in the standardization of PCR-based DNA techniques. These assays are now being incorporated into care pathways and diagnostic algorithms; they help us to steward and monitor antifungal therapies and to predict treatment outcomes.

Complications of hematopoietic stem transplantation: Fungal infections

Patients undergoing allogeneic hematopoietic stem cell transplantation (HSCT) are at increased risk of invasive fungal infections, especially during the early neutropenic phase and severe graft-versus-host disease. Mold-active prophylaxis should be limited to the highest risk groups. Empiric antifungal therapy for HSCT with persistent febrile neutropenia is associated with unacceptable response rates, unnecessary antifungal therapy, increased risk of toxicity, and inflated costs. Empiric therapy should not be a substitute for detailed work up to identify the cause of fever in such patients. The improved diagnostic performance of serum biomarkers such as galactomannan and β-D-glucan, as well as polymerase chain reaction assays has allowed the development of diagnostic-driven antifungal therapy strategies for high risk patients. Diagnostic-driven approaches have resulted in reduced unnecessary antifungal exposure, improved diagnosis of invasive fungal disease, and reduced costs without increased risk of mortality. The appropriateness of diagnostic-driven antifungal strategy for individual HSCT centers depends on the availability and turnaround times for diagnostics, multidisciplinary expertise, and the local epidemiology of invasive fungal infections. Echinocandins are the treatment of choice for invasive candidiasis in most HSCT recipients. Fluconazole may be used for the treatment of invasive candidiasis in hemodynamically stable patients with no prior azole exposure. The primary treatment of choice for invasive aspergillosis is voriconazole. Alternatives include isavuconazole and lipid formulations of amphotericin. Currently available evidence does not support routine primary combination antifungal therapy for invasive aspergillosis. However, combination salvage antifungal therapy may be considered in selected patients. Therapeutic drug monitoring is recommended for the majority of HSCT recipients on itraconazole, posaconazole, or voriconazole.

Invasive Aspergillosis in Hematological Patients

Invasive aspergillosis (IA) is still one of the leading causes of morbidity and mortality in hematological patients, although its outcome has been improving. Prolonged and profound neutropenia in patients receiving intensive chemotherapy for acute leukemia and stem cell transplantation is a major risk factor for IA. Allogeneic stem cell transplant recipients with graft-versus-host disease and corticosteroid use are also at high risk. Management in a protective environment with high efficiency particular air (HEPA) filter is generally recommended to prevent aspergillosis in patients with prolonged and profound neutropenia. Antifungal prophylaxis against Aspergillus species should be considered in patients with past history of aspergillosis or colonization of Aspergillus species, at facilities with high incidence of IA and those without a protective environment. Early diagnosis and prompt antifungal treatment is important to improve outcome. Imaging studies such as computed tomography and biomarkers such as galactomannan antigen and β-D-glucan are useful for early diagnosis. Empirical antifungal treatment based on persistent or recurrent fever during neutropenia despite broad-spectrum antibiotic therapy is generally recommended in high-risk patients. Alternatively, a preemptive treatment strategy has recently been proposed in the context of progress in the early diagnosis of IA based on the results of imaging studies and biomarkers. Voriconazole is recommended for initial therapy for IA. Liposomal amphotericin B is considered as alternative initial therapy. Combination antifungal therapy of echinocandin with voriconazole or liposomal amphotericin B could be a choice for refractory cases.

Management of infection during chemotherapy for acute leukemia in Japan: a nationwide questionnaire-based survey by the Japan Adult Leukemia Study Group

PURPOSE

We performed a nationwide questionnaire-based survey to evaluate the current clinical practices of infectious complications during chemotherapy for acute leukemia in Japan.

METHODS

We e-mailed a questionnaire to member institutions of the Japan Adult Leukemia Study Group in September, 2013. The questionnaire consisted of 50 multiple-choice questions covering therapeutic environment, antimicrobial prophylaxis, screening test during neutropenia, empirical therapy for febrile neutropenia, and the use of granulocyte-colony stimulating factor. The results were compared to those of previous surveys conducted in 2001 and 2007, and also to the recommendations described in the guidelines.

RESULTS

Usable responses were received from 141 out of 222 (63.5%) institutions. Chemotherapy for acute myeloid leukemia was performed in protective environment in 90% of the institutions, which increased compared to previous survey (76%). Fluoroquinolones and fluconazole were the most commonly used antimicrobial agents for antibacterial and antifungal prophylaxis, followed by sulfamethoxazole-trimethoprim and itraconazole, respectively. In empirical therapy for febrile neutropenia, monotherapy with β-lactum antibiotics was the first-line therapy in most of the institutions. While empirical antifungal therapy was adopted for persistent fever in more than half of the institutions, preemptive/presumptive therapy was also used in approximately 40% of the institutions. Most of the clinicians were reluctant to use granulocyte-colony stimulating factor routinely in chemotherapy for acute myeloid leukemia.

CONCLUSIONS

This study clarified the current clinical practices of infectious complications during chemotherapy for acute leukemia and would provide important information for the development of a suitable guideline in Japan.

Laboratory Diagnostics for Fungal Infections: A Review of Current and Future Diagnostic Assays

This article reviews the current diagnostic approaches, both serologic and molecular, for the detection of fungi associated with pulmonary disease. Classic serologic techniques, including immunodiffusion and complement fixation, both of which remain a cornerstone for fungal diagnostic testing, are reviewed and their performance characteristics presented. More recent advances in this field, including novel lateral-flow assays for fungal antigen detection, are also described. Molecular techniques for fungal identification both from culture and directly from patient specimens, including nucleic acid probes, mass spectrometry-based methods, nucleic acid amplification testing, and traditional and broad-range sequencing, are discussed and their performance evaluated.

The misleading effect of serum galactomannan testing in high-risk haematology patients receiving prophylaxis with micafungin

OBJECTIVES

To investigate the performance of the routine serum galactomannan (sGM) assay in the diagnosis of invasive aspergillosis (IA) in high-risk haematology patients receiving prophylaxis with micafungin.

METHODS

Retrospective study including all haematological patients who received prophylaxis with micafungin during high-risk IA episodes (neutropenic patients after chemotherapy for acute myeloid leukaemia/myelodysplastic syndrome; allogeneic haematopoietic stem-cell transplantation during early neutropenic phase or graft-versus-host disease requiring high prednisone doses) and for whom at least one sGM result was available. Episodes were classified as follows: true-positive (positive GM in the context of IA), false-positive (positive GM result in patients who had no evidence of IA), true-negative (negative GM test results and no IA), or false-negative (negative GM test in the context of IA). Non-evaluable patients were excluded.

RESULTS

Among 146 evaluable episodes, four were true-positive in the context of probable breakthrough IA (incidence of breakthrough IA, 2.7%); 111/146 high-risk episodes (76%) were considered true-negative and 31/146 (21.2%) were considered false-positive. No false-negative episodes were detected. All but one of the false-positive episodes were detected in surveillance GM tests, leading to high-resolution CT scans in eight cases (8/31; 25.8%), all of which were negative. The positive predictive and negative predictive values of sGM for surveillance and diagnostic approaches were 3.2% (1/31) and 100% (110/110) and 75% (3/4) and 100% (1/1), respectively.

CONCLUSIONS

Surveillance of asymptomatic patients receiving prophylaxis with micafungin using sGM is unnecessary, because the results are either negative or false-positive. However, sGM remains useful in the diagnosis of breakthrough IA in symptomatic patients during prophylaxis.

Performance of Galactomannan Antigen, Beta-d-Glucan, and Aspergillus-Lateral-Flow Device for the Diagnosis of Invasive Aspergillosis

Aspergillus lateral-flow device (LFD) was recently introduced as a practical tool for the diagnosis of invasive aspergillosis (IA). We investigated the performance of Aspergillus-LFD as a point-of-care test for the diagnosis of IA. Serum samples were collected twice weekly from patients who received intensive chemotherapy for acute leukemia, or recepients of allogeneic stem cell transplantation. Aspergillus galactomannan (GM) antigen, 1,3-beta-d-glucan and Aspergillus-LFD tests were carried out according to manufacturers' recommendations. GM testing was repeated with a modified procedure which was proven to increase the sensitivity. Aspergillus-LFD was performed without applying any pretreatment procedure to allow the kit to fit as a point-of-care test. Fungal infections were categorized according to European Organization for Research and Treatment of Cancer/Invasive Fungal Infections Cooperative Group and the National Institute of Allergy and Infectious Diseases Mycoses Study Group (EORTC/MSG) criteria. A total of 75 neutropenia episodes in 64 patients were prospectively followed between February 2012 and January 2013. Probable IA was diagnosed in 11 patients, probable pulmonary fungal disease was diagnosed in one patient, and rhinocerebral aspergillosis was diagnosed in one patient. Fungemia was detected in two patients. Aspergillus-LFD was positive in serum of a patient with probable IA and in the bronchoalveolar lavage fluid of an other patient with probable IA. Aspergillus-LFD was false positive in serum of two patients. Although there was no radiological finding of IA or documented fungemia, fever resolved after empirical caspofungin therapy in one of these patients. The sensitivity of Aspergillus-LFD as a point-of-care test without any pretreatment of serum sample is low.

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.

Immunity status of invasive pulmonary aspergillosis patients with structural lung diseases in Chinese adults

BACKGROUND

Invasive pulmonary aspergillosis (IPA) is a fungal infection frequently observed in patients with immune dysfunction, such as those suffering from structural lung diseases. Nevertheless, studies assessing IPA combined with other common respiratory diseases remain scarce, particularly those regarding the immune status of its patients. Different structural lung diseases are known to differently affect patient immune status; however, the mechanisms by which this is conferred have yet to be determined. Thus, our study aims to compare the immune status of IPA patients with the structural lung diseases chronic obstructive pulmonary diseases (COPD), interstitial lung disease (ILD) and non-cystic fibrosis bronchiectasis (NCFB).

METHODS

This study was performed retrospectively with data collected over the years 2004 to 2013 at Shanghai Pulmonary Hospital, Tongji University, and included 77 patients whose lower respiratory tract (LRT) samples tested positive for. Our analysis considered blood examinations of CD3+, CD4+, CD8+, CD4+/CD8+, IgG, IgA and IgM levels.

RESULTS

CD4+/CD8+ double positive cells, representing cell-mediated immunity, were less abundant in IPA patients with COPD than those with ILD and NCFB (0.81±0.09 vs. 1.39±0.25 and 0.81±0.09 vs. 1.57±0.06, respectively, P<0.001). In agreement with this result, corticosteroid and broad-spectrum antibiotic use were most common in individuals with COPD (57%). IgA levels, which indicate humoral immunity, were lower in IPA patients with NCFB than those with COPD or ILD (0.95±0.28 vs. 1.64±0.40 g/L and 0.95±0.28 vs. 3.16±0.83 g/L, respectively, P<0.001).

CONCLUSIONS

Immunity status differs between IPA patients with different structural lung diseases. Among IPA patients with COPD, ILD and NCFB, those with COPD have the lowest cell-mediated immunity, while those with NCFB have the lowest humoral immunity.

Recommendations for Risk Categorization and Prophylaxis of Invasive Fungal Diseases in Hematological Malignancies: A Critical Review of Evidence and Expert Opinion (TEO-4)

This is the last of a series of articles on invasive fungal infections prepared by opinion leaders in Turkey. The aim of these articles is to guide clinicians in managing invasive fungal diseases in hematological malignancies and stem cell transplantation based on the available best evidence in this field. The previous articles summarized the diagnosis and treatment of invasive fungal disease and this article aims to explain the risk categorization and guide the antifungal prophylaxis in invasive fungal disease.

Serological Approaches

The diagnosis of invasive fungal diseases (IFD) based on clinical, radiological, and conventional microbiological findings is not reliable and is often delayed. Non-culture-based methods with higher sensitivity and specificity may reduce diagnostic time and result in decreased IFD morbidity and mortality. These methods are now increasingly used to manage patients at risk of IFD. Among available biomarkers, fungal antigens have been investigated as an aid to early diagnosis and are predominantly used as screening tests to prompt antifungal treatment mainly in patients with hematological malignancies. The revised version of the European Organization for Research and Treatment of Cancer/Mycoses Study Group (EORTC/MSG) consensus definitions includes some of these biological markers (galactomannan, 1,3-beta-D-glucan, cryptococcus antigen).

EPICO 3.0. Empirical antifungal therapy in critically-ill hematology patients

BACKGROUND

Although in the past decade the management of invasive fungal infections has improved, a number of controversies persist regarding empirical antifungal treatment in critically-ill hematology patients.

AIMS

To identify key clinical knowledge to elaborate a set of recommendations, with a high level of consensus, necessary for the approach to fungal infections in critically-ill hematology patients.

METHODS

A Spanish prospective questionnaire, which measures consensus through the Delphi technique, was anonymously answered and e-mailed by 30 multidisciplinary national experts, all specialists in fungal invasive infections from six scientific national societies; intensivists, anesthesiologists, microbiologists, pharmacologists and specialists in infectious diseases. They responded to 10 questions prepared by the coordination group after a thorough review of the literature published in the last few years. For a category to be selected, the level of agreement among the experts in each category must be equal to or greater than 70%. In a second round, 73 specialists attended a face-to-face meeting held after extracting the recommendations from the chosen topics, and validated the pre-selected recommendations and derived algorithm.

RESULTS

Assess administering antifungal treatment to patients with high/medium risk factors and fever for over 4 days after onset of antibiotic therapy, and in the event of negative galactomannan or if no detection analysis has been performed and no relevant findings in the sinus and chest computed tomography (CT) have been detected, (1) in the case the patient did not receive prophylaxis, or was administered fluconazole, caspofungin treatment is recommended; (2) in the event the patient received prophylaxis with an azole with activity against filamentous fungi, the administration of liposomal amphotericin B is recommended and caspofungin as second choice therapy; (3) in the event that the prophylaxis received was an echinocandin, liposomal amphotericin B therapy is recommended and voriconazole as second choice. Assess administering antifungal treatment in patients with high/medium risk factors and fever for more than 4 days after onset of antibiotic therapy, and in the event of a positive galactomannan and/or sinus and chest CT suggests fungal infection caused by filamentous fungi, (1) in the event the patient did not receive antifungal prophylaxis or was administered fluconazole, the recommended treatment of choice is voriconazole or liposomal amphotericin B; (2) if the patient received prophylaxis with an azole with activity against filamentous fungi, the administration of liposomal amphotericin B with caspofungin is recommended and monotherapy with liposomal amphotericin B or the combination of voriconazole and anidulafungin are recommended as second choice therapies; (3) in the event an echinocandin was administered as prophylaxis, liposomal amphotericin B or voriconazole are the recommended treatments of choice. Consider the administration of antifungal treatment in patients with high/medium risk factors and fever for more than 4 days after onset of antibiotic therapy, and in the event of a negative galactomannan and the sinus and chest CT suggests fungal infection caused by filamentous fungi, (1) if the patient did not receive prophylaxis or was administered fluconazole, the recommended treatment of choice is liposomal amphotericin B or voriconazole; (2) in the case the patient received prophylaxis with an azole with activity against filamentous fungi, the administration of liposomal amphotericin B is recommended as first choice therapy and liposomal amphotericin B combined with caspofungin as second choice; (3) in the event an echinocandin was administered as prophylaxis, liposomal amphotericin B or voriconazole are the recommended treatments of choice.

CONCLUSIONS

The empirical antifungal approach in critically-ill hematology patients requires the application of the broad range of knowledge and skills described in our recommendations and algorithm. These recommendations, based on the DELPHI methodology, may help to identify potential patients, standardize their management and improve overall prognosis.

1,3-ß-d-Glucan testing is highly specific in patients undergoing dialysis treatment

BACKGROUND

The aim of this combined in-vitro and in-vivo study was to investigate whether state of the art dialysis modalities produce false positive serum 1,3-ß-d-Glucan (BDG) levels.

METHODS

Dialysis fluid for simulated dialysis treatments was spiked with BDG from different sources. Samples were taken from the dialysate and dialyzer blood compartments at various time points. In addition, serum samples were obtained in three groups of patients without invasive fungal disease: a.) twelve patients on chronic hemodialysis (HD)/hemodiafiltration (HDF); b.) ten patients on continuous ambulatory peritoneal dialysis (CAPD); and c.) ten patients with stable chronic kidney disease (CKD) but without dialysis.

RESULTS

Median BDG levels in BDG spiked dialysate were 3250.9, 2050.4, and 390.1 pg/ml respectively. All corresponding samples from the blood compartments were BDG negative. In HD/HDF patients no increase of serum BDG levels could be observed over the duration of treatment. 71/72 BDG tests in this group remained negative. BDG tests were also negative in 9/10 CAPD patients, both in in- and outflow dialysates as well as in all ten patients with CKD.

CONCLUSION

We conclude that state of the art renal replacement therapies using up-to-date treatments are not a cause of falsely elevated serum BDG levels.

Laboratory Diagnosis of Central Nervous System Infection

Central nervous system (CNS) infections are potentially life threatening if not diagnosed and treated early. The initial clinical presentations of many CNS infections are non-specific, making a definitive etiologic diagnosis challenging. Nucleic acid in vitro amplification-based molecular methods are increasingly being applied for routine microbial detection. These methods are a vast improvement over conventional techniques with the advantage of rapid turnaround and higher sensitivity and specificity. Additionally, molecular methods performed on cerebrospinal fluid samples are considered the new gold standard for diagnosis of CNS infection caused by pathogens, which are otherwise difficult to detect. Commercial diagnostic platforms offer various monoplex and multiplex PCR assays for convenient testing of targets that cause similar clinical illness. Pan-omic molecular platforms possess potential for use in this area. Although molecular methods are predicted to be widely used in diagnosing and monitoring CNS infections, results generated by these methods need to be carefully interpreted in combination with clinical findings. This review summarizes the currently available armamentarium of molecular assays for diagnosis of central nervous system infections, their application, and future approaches.

Performance evaluation of multiplex PCR including Aspergillus-not so simple!

Multiplex PCRs have been designed for including species other than Aspergillus fumigatus for the diagnosis of invasive aspergillosis, such as microarrays, liquid-phase array, and electrospray-ionization mass spectrometry (PCR/ESI MS). These methods are based on the selection of multiple primers to amplify different species with the specificity checked by hybridization to a probe or by base composition of the amplicon for the PCR/ESI MS. When testing complex samples such as respiratory specimens, some clinically relevant species can be missed. Indeed, it is impossible to design primers able to amplify all the known fungal species with the same efficiency. Therefore, the best amplified species may not be the most clinically relevant. Multiplex assays have also been proposed to detect A. fumigatus DNA and azole resistance. Since the gene responsible for azole resistance is single copy and the gene used for detection is multicopy, only the high fungal loads can be evaluated. Thus, although interesting for investigating mycobiome, the multiplex assays should be used with cautious for the diagnosis of IA or the detection of resistance. For the diagnosis of invasive aspergillosis, validated quantitative PCRs specifically targeting A. fumigatus or a limited set of species to increase sensitivity is a safer option.

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

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

PCR Technology for Detection of Invasive Aspergillosis

The application of molecular technologies to aid diagnosis and management of infectious diseases has had a major impact and many assays are in routine use. Diagnosis of aspergillosis has lagged behind. Lack of standardization and limited commercial interest have meant that PCR was not included in consensus diagnostic criteria for invasive fungal disease. In the last ten years careful evaluation and validation by the Aspergillus European PCR initiative with the development of standardized extraction, amplification and detection protocols for various specimen types, has provided the opportunity for clinical utility to be investigated. PCR has the potential to not only exclude a diagnosis of invasive aspergillosis but in combination with antigen testing may offer an approach for the early diagnosis and treatment of invasive aspergillosis in high-risk populations, with the added benefit of detection of genetic markers associated with antifungal resistance.

Fungal infections in the ICU: advances in treatment and diagnosis

PURPOSE OF REVIEW

The aim of this review is to give an update on the available diagnostic approaches and currently adopted therapeutic management of severe fungal diseases in the ICU setting.

RECENT FINDINGS

In order to reduce the clinical impact of life-threatening Candida infections, prompt diagnosis and appropriate treatment are strictly required. Preemptive strategies, mainly based on serological markers [i.e., (1-3)-β-D-glucan assay] are progressively replacing prophylactic and empirical approaches, limiting inadequate antifungal use. For the diagnosis of aspergillosis new algorithm has been recently validated, supported by the better knowledge of galactomannan antigen kinetic as a clinical marker. Echinocandins and voriconazole are the first choice drugs for the treatment of invasive Candida and Aspergillus infections, respectively. Although rare, other fungal infections (i.e., Pneumocystis jirovecii, Cryptococcus spp., and Mucorales spp.) may be responsible for life-threatening diseases in ICU patients, and early diagnosis and appropriate treatment are also important.

SUMMARY

Critically ill patients may frequently experience severe invasive fungal infections. Biomarkers-based diagnostic approaches give, at the same time, the possibility to early detect the ongoing infection and reduce inappropriate antifungal therapy in nonconfirmed cases. Potent and well tolerated drugs are now available for the treatment of proven cases but clinicians should carefully consider the risk of treatment failure and the availability of new monitoring and therapeutic 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.

Galactomannan and 1,3-β-d-Glucan Testing for the Diagnosis of Invasive Aspergillosis

Invasive aspergillosis (IA) is a severe complication among hematopoietic stem cell transplant recipients or patients with hematological malignancies and neutropenia following anti-cancer therapy. Moreover, IA is increasingly observed in other populations, such as solid-organ transplant recipients, patients with solid tumors or auto-immune diseases, and among intensive care unit patients. Frequent delay in diagnosis is associated with high mortality rates. Cultures from clinical specimens remain sterile in many cases and the diagnosis of IA often only relies on non-specific radiological signs in the presence of host risk factors. Tests for detection of galactomannan- (GM) and 1,3-β-d-glucan (BDG) are useful adjunctive tools for the early diagnosis of IA and may have a role in monitoring response to therapy. However, the sensitivity and specificity of these fungal biomarkers are not optimal and variations between patient populations are observed. This review discusses the role and interpretation of GM and BDG testing for the diagnosis of IA in different clinical samples (serum, bronchoalveolar lavage fluid, cerebrospinal fluid) and different groups of patients (onco-hematological patients, solid-organ transplant recipients, other patients at risk of IA).

Recent developments in the management of invasive fungal infections in patients with oncohematological diseases

Patients with hematological cancer have a high risk of invasive fungal diseases (IFDs). 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 molds are increasingly be identified in cases of documented IFDs. Important risk factors are long lasting granulocytopenia with neutrophil counts below 500/μl for more than 10 days or graft-versus-host disease resulting from allogeneic stem-cell transplantation. For definite diagnosis of IFD, various diagnostic tools have to be applied, including conventional mycological culture and nonconventional microbiological tests such as antibody/antigen and molecular tests, as well as histopathology and radiology. In the last few years, various laboratory methods, like the Aspergillus GM immunoassay (Aspergillus GM EIA), 1,3-ß-D-glucan (BG) assay or polymerase chain reaction (PCR) techniques have been developed for better diagnosis. Since no single indirect test, including radiological methods, provides the definite diagnosis of an invasive fungal infection, the combination of different diagnostic procedures, which include microbiological cultures, histological, serological and molecular methods like PCR together with the pattern of clinical presentation, may currently be the best strategy for the prompt diagnosis, initiation and monitoring of IFDs. Early start of antifungal therapy is mandatory, but clinical diagnostics often do not provide clear evidence of IFD. Integrated care pathways have been proposed for management and therapy of IFDs with either the diagnostic driven strategy using the preemptive antifungal therapy as opposed to the clinical or empirical driven strategy using the 'traditional' empirical antifungal therapy. Antifungal agents preferentially used for systemic therapy of invasive fungal infections are amphotericin B preparations, fluconazole, voriconazole, posaconazole, caspofungin, anidulafungin, micafungin, and most recently isavuconazole. Clinical decision making must consider licensing status, local experience and availability, pharmacological and economic aspects.

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

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