The current management landscape: aspergillosis

Identification and validation of diagnostic cut-offs of the ELISpot assay for the diagnosis of invasive aspergillosis in high-risk patients

OBJECTIVE

We investigated the performance of enzyme linked immunospot (ELISpot) assay for the diagnosis of invasive aspergillosis (IA) in high-risk patients with hematologic malignancies.

METHODS

We prospectively enrolled two cohorts of patients undergoing intensive myelosuppressive or immunosuppressive treatments at high risk for IA. ELISpot was performed to detect Aspergillus-specific T cells producing Interleukin-10.

RESULTS

In the discovery cohort, a derived cut-off of 40 spot forming cells (SFCs)/106 PBMCs has shown to correctly classify IA cases with a sensitivity and specificity of 89.5% and 88.6%, respectively. This cut-off is lowered to 25 SFC when considering the subset of possible IA patients, with sensitivity and specificity of 76% and 93%, respectively. The application of the 40 SFCs cut-off to the validation cohort resulted in a positivity rate of 83.3% in proven/probable cases and a negativity rate of 92.5% in possible/non-IA cases. Adopting the 25 SCFs cut-off, the assay resulted positive in 83.3% of proven/probable cases while it resulted negative in 66.7% of possible/non-IA cases.

CONCLUSIONS

ELISpot shows promises in the diagnosis of IA and the possibility to use two distinct cut-offs with similar diagnostic performances according to patients' different pre-test probability of infection can widen its use in patients at risk.

Invasive Pulmonary Aspergillosis in Coronavirus Disease 2019 Patients Lights and Shadows in the Current Landscape

Invasive pulmonary aspergillosis (IPA) presents a known risk to critically ill patients with SARS-CoV-2; quantifying the global burden of IPA in SARS-CoV-2 is extremely challenging. The true incidence of COVID-19-associated pulmonary aspergillosis (CAPA) and the impact on mortality is difficult to define because of indiscriminate clinical signs, low culture sensitivity and specificity and variability in clinical practice between centers. While positive cultures of upper airway samples are considered indicative for the diagnosis of probable CAPA, conventional microscopic examination and qualitative culture of respiratory tract samples have quite low sensitivity and specificity. Thus, the diagnosis should be confirmed with serum and BAL GM test or positive BAL culture to mitigate the risk of overdiagnosis and over-treatment. Bronchoscopy has a limited role in these patients and should only be considered when diagnosis confirmation would significantly change clinical management. Varying diagnostic performance, availability, and time-to-results turnaround time are important limitations of currently approved biomarkers and molecular assays for the diagnosis of IA. The use of CT scans for diagnostic purposes is controversial due to practical concerns and the complex character of lesions presented in SARS-CoV-2 patients. The key objective of management is to improve survival by avoiding misdiagnosis and by initiating early, targeted antifungal treatment. The main factors that should be considered upon selection of treatment options include the severity of the infection, concomitant renal or hepatic injury, possible drug interactions, requirement for therapeutic drug monitoring, and cost of therapy. The optimal duration of antifungal therapy for CAPA is still under debate.

Should serum biomarker monitoring replace primary antifungal chemoprophylaxis in patients with acute leukaemia receiving systemic anti-cancer therapy? A PRO/CON debate

Fungal infection exacts a severe burden on patients with acute leukaemia. Azole prophylaxis attempts to mitigate this impact but is associated with toxicity and cost as well as the potential to select for resistance. The development of biomarkers including galactomannan and β-1,3-d-glucan may improve detection of early disease and thus reduce the need for prophylaxis, though these assays also have their limitations. In this debate, Howard et al. argue in favour of continuing chemoprophylaxis in patients with acute leukaemia receiving systemic chemotherapy, citing the multiple randomized control trials and meta-analyses that demonstrate its efficacy. Taynton et al. argue that fungal biomarker surveillance in the absence of primary antifungal chemoprophylaxis is a safe alternative that could reduce antifungal use and the development of resistance.

Future challenges and chances in the diagnosis and management of invasive mould infections in cancer patients

Diagnosis, treatment, and management of invasive mould infections (IMI) are challenged by several risk factors, including local epidemiological characteristics, the emergence of fungal resistance and the innate resistance of emerging pathogens, the use of new immunosuppressants, as well as off-target effects of new oncological drugs. The presence of specific host genetic variants and the patient's immune system status may also influence the establishment of an IMI and the outcome of its therapy. Immunological components can thus be expected to play a pivotal role not only in the risk assessment and diagnosis, but also in the treatment of IMI. Cytokines could improve the reliability of an invasive aspergillosis diagnosis by serving as biomarkers as do serological and molecular assays, since they can be easily measured, and the turnaround time is short. The use of immunological markers in the assessment of treatment response could be helpful to reduce overtreatment in high risk patients and allow prompt escalation of antifungal treatment. Mould-active prophylaxis could be better targeted to individual host needs, leading to a targeted prophylaxis in patients with known immunological profiles associated with high susceptibility for IMI, in particular invasive aspergillosis. The alteration of cellular antifungal immune response through oncological drugs and immunosuppressants heavily influences the outcome and may be even more important than the choice of the antifungal treatment. There is a need for the development of new antifungal strategies, including individualized approaches for prevention and treatment of IMI that consider genetic traits of the patients.

Lay Abstract

Anticancer and immunosuppressive drugs may alter the ability of the immune system to fight invasive mould infections and may be more important than the choice of the antifungal treatment. Individualized approaches for prevention and treatment of invasive mold infections are needed.

Clinical study on empirical and diagnostic-driven (pre-emptive) therapy of voriconazole in severe aplastic anaemia patients with invasive fungal disease after intensive immunosuppressive therapy

The aim of this study is to compare the curative effect of empirical with diagnostic-driven (pre-emptive) therapy of voriconazole in severe aplastic anaemia patients (SAAs) with invasive fungal disease (IFD) after intensive immunosuppressive therapy (IST). Patients undergoing voriconazole antifungal therapy were randomized to empirical therapy group and diagnostic-driven therapy group. Empirical therapy group accounted for 48.5% of all cases, and diagnostic-driven therapy group accounted for 51.5%. The morbidity of IFD (probable and proven cases) was slightly increased in diagnostic-driven therapy group compared with empirical therapy group (P > 0.05). The total effective rate was 62.1%. The effective rate in empirical therapy group was 78.1%, which was significantly increased compared with diagnostic-driven therapy group (47.1%) (P < 0.05). This value was especially significant in possible IFD cases (P < 0.05). The efficacy of possible IFD cases in empirical therapy group was the best (84%) followed by the probable and proven cases in empirical therapy group (57.1%). In diagnostic-driven therapy group, the efficacy of possible IFD cases was 50%, and the efficacy of probable and proven cases was only 37.5%. The difference was statistically significant (P < 0.05). Absolute neutrophil count (ANC) is the key anti-infection factor. The efficacy of patients whose ANC ˂ 0.1 × 10⁹/L was 39.28%, which was significantly reduced compared with that of patients whose ANC ≥ 0.1 × 10⁹/L (78.95%) (P < 0.05). This finding was especially obvious in diagnostic-driven therapy group. As empirical therapy is superior to diagnostic-driven therapy, we recommend that empirical therapy should be started for high-risk patients, and efforts should be made to definitively diagnose the disease.

Pulmonary Aspergillosis: An Evolving Challenge for Diagnosis and Treatment

Aspergillus is a mold that may lead to different clinical pictures, from allergic to invasive disease, depending on the patient’s immune status and structural lung diseases. Chronic pulmonary aspergillosis is an infection with a locally invasive presentation, reported especially in patients with chronic pulmonary disease, while aspergilloma is typically found in patients with previously formed cavities in the lungs. Allergic bronchopulmonary aspergillosis is due to a hypersensitivity reaction to Aspergillus antigens and is more frequently described in patients with moderate-severe asthma or cystic fibrosis. Invasive pulmonary aspergillosis mainly occurs in patients with neutropenia or immunodeficiency, but has increasingly been recognized as an emerging disease of non-neutropenic patients. The significance of this infection has dramatically increased in recent years, considering the high number of patients with an impaired immune state associated with the management and treatment of neoplasm, solid or hematological transplantation, autoimmune diseases, and inflammatory conditions. Moreover, prolonged steroid treatment is recognized as an important risk factor, especially for invasive disease. In this setting, critically ill patients admitted to intensive care units and/or with chronic obstructive pulmonary disease could be at higher risk for invasive infection. This review provides an update on the clinical features and risk factors of pulmonary aspergillosis. Current approaches for the diagnosis, management, and treatment of these different forms of pulmonary aspergillosis are discussed.

Pre-transplant sTIM-3 levels may have a predictive impact on transplant outcome in acute leukemia patients

Objectives: T-cell immunoglobulin and mucin domain-containing protein-3 (TIM-3) is considered as a negative regulator of T-cell driven immune response. This study is planned to investigate the prognostic role of pre-transplant soluble TIM-3 (sTIM-3) levels in allogeneic hematopoietic stem cell transplantation (allo-HSCT) recipients. Methods: Pre-transplant serum sTIM-3 levels were measured in 177 allo-HSCT recipients [median age: 36(16-66) years; male/female: 111/66]. Results: Pre-transplant sTIM-3 levels were significantly higher in acute myeloid leukemia (AML) patients compared to acute lymphoblastic leukemia (ALL) patients (p = 0.01). Pre-transplant sTIM-3 levels were significantly lower in patients with abnormal cytogenetics (p = 0.017). Pre-transplant sTIM-3 levels were significantly higher in patients who developed viral hemorrhagic cystitis (p = 0.034). A positive correlation was demonstrated between sTIM-3 levels and acute graft versus host disease (GvHD) grade (p = 0.013; r = 0.299). Overall survival (OS) was not statistically different between low- and high-TIM-3 groups (%35.2 vs %20.4; p > 0.05). Primary diagnosis (p = 0.042), sinusoidal obstruction syndrome (p < 0.001), acute GvHD (p = 0.001), chronic GvHD (p = 0.009) and post-transplant relapse (p = 0.003) represented significant impact on OS. Discussion: Increased sTIM-3 levels in AML patients seem to be compatible with the previous reports. The inhibitor role of TIM-3 in cellular immune response may be a possible explanation for the association of sTIM-3 with viral infections and GvHD. However, the main challenge remains to be the ambiguous association of pre-transplant sTIM-3 levels and post-transplant complications, as allo-HSCT recipients are expected to represent donor genetic features in the post-transplant setting. Conclusion: Further studies are warranted to clarify the particular role of sTIM-3 in the allo-HSCT setting.

Aspergillus fumigatus and Aspergillosis in 2019

Aspergillus fumigatus is a saprotrophic fungus; its primary habitat is the soil. In its ecological niche, the fungus has learned how to adapt and proliferate in hostile environments. This capacity has helped the fungus to resist and survive against human host defenses and, further, to be responsible for one of the most devastating lung infections in terms of morbidity and mortality. In this review, we will provide (i) a description of the biological cycle of A. fumigatus; (ii) a historical perspective of the spectrum of aspergillus disease and the current epidemiological status of these infections; (iii) an analysis of the modes of immune response against Aspergillus in immunocompetent and immunocompromised patients; (iv) an understanding of the pathways responsible for fungal virulence and their host molecular targets, with a specific focus on the cell wall; (v) the current status of the diagnosis of different clinical syndromes; and (vi) an overview of the available antifungal armamentarium and the therapeutic strategies in the clinical context. In addition, the emergence of new concepts, such as nutritional immunity and the integration and rewiring of multiple fungal metabolic activities occurring during lung invasion, has helped us to redefine the opportunistic pathogenesis of A. fumigatus.

Effect of benomyl and diazinon on acquired azole resistance in Aspergillus flavus and expression of mdr1 and cyp51c genes

Background and Purpose:

Aspergillus flavus is an important pathogen in immunodeficient patients. Due to the abundance of this fungus in nature, fungicides are commonly used to preserve and maintain agricultural products. Long-term exposure to these pesticides can lead to the induction of drug resistance in this fungus.

Materials and Methods:

For the purpose of the study, 10 strains of A. flavus ATCC 204304 were cultured in benomyl and diazinon pesticides at the concentrations of 62.5, 125, 250.500, 750, 1000, 1500, 2000, and 2500 mg/L in nine steps. Morphological changes and resistance to voriconazole, itraconazole, and amphotericin B were evaluated at the end of each step. Subsequently, changes in the expression of mdr1 and cyp51C genes were studied in the strains showing drug resistance.

Results:

The results showed that during the nine stages of the adjacency of strains with benomyl and diazinon at different concentrations, resistance to voriconazole, itraconazole, and amphotericin B in these toxins increased by 30% and 10%, respectively. In addition, the microscopic examination of resistant strains revealed the absence of sporulation, and only mycelium was found. Macroscopically, the color of the colonies changed from green to white. Furthermore, the investigation of the expression of mdr1 and cyp51c genes in these strains showed a decrease and increase in adjacency with diazinon and benomyl, respectively.

Conclusion:

As the findings indicated, exposure to agricultural pesticides can lead to the incidence of morphological changes and resistance to amphotericin B, itraconazole, and voriconazole in the sensitive species of A. flavus by altering the expression of genes involved in drug resistance.

[Invasive aspergillosis in the patient with oncohematologic disease]

Invasive aspergillosis is the most common invasive fungal infection in patients with acute hematological malignancies or treated with hematopoietic stem cell transplantation due to the marked alteration of the physiological mechanisms of antifungal immunity that takes place in these situations. For this reason, antifungal prophylaxis has a relevant role in these patients. The introduction of new antifungal agents has motivated the updating of recommendations for prophylaxis and treatment in different guidelines. The objectives of this chapter are a brief review of the mechanisms of immunity against fungi, the definition of risk for developing an invasive fungal infection and an update of the prophylaxis recommendations and treatment of invasive aspergillosis in the group of patients with hematological diseases.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Fungal infections in solid organ transplantation: An update on diagnosis and treatment

Invasive fungal infections constitute an important cause of morbidity and mortality in solid organ transplantation recipients. Since solid organ transplantation is an effective therapy for many patients with end-stage organ failure, prevention and treatment of fungal infections are of vital importance. Diagnosis and management of these infections, however, remain difficult due to the variety of clinical symptoms in addition to the lack of accurate diagnostic methods. The use of fungal biomarkers can lead to an increased diagnostic accuracy, resulting in improved clinical outcomes. The evidence for optimal prophylactic approaches remains inconclusive, which results in considerable variation in the administration of prophylaxis. The implementation of a standard protocol for prophylaxis remains difficult as previous treatment regimens, which can alter the distribution of different pathogens, affect the outcome of antifungal susceptibility testing. Furthermore, the increasing use of antifungals also contributes to incremental costs and the risk of development of drug resistance. This review will highlight risk factors, clinical manifestations and timing of fungal infections and will focus predominately on the current evidence for diagnosis and management of fungal infections.

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

OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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

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

Morphological changes and induction of antifungal resistance in Aspergillus fumigatus due to different CO2 levels

Background and Purpose

Aspergillosis is one of the most common opportunistic fungal infections in immunocompromised and neutropenic patients. Aspergillus fumigatus (A. fumigatus) is the most common causative agent of this infection. Due to variable CO₂ concentrations that pathogens are exposed to during the infection process and to understand the role of CO₂, we examined the effects of various CO₂ concentrations as one of the environmental factors on morphological changes and induction of antifungal resistance in A. fumigatus.

Materials and Methods

A. fumigatus strains were cultured and incubated under 1%, 3%, 5%, and 12% CO₂ atmospheres, each time for one, two, and four weeks. The control culture was maintained for one week without CO₂ atmosphere. Morphological changes were investigated and antifungal susceptibility test was performed according to the recommendations of the Clinical and Laboratory Standards Institute (CLSI) M38-A2 document. The results of different CO₂ atmospheres were compared with that of the control sample.

Results

We found that 1%, 3%, 5%, and 12% CO₂ atmospheres were associated with morphological colony changes. Macroscopically, the colonies were shallow dark green, smooth, crisp to powdery with reduced growth; microscopic examination revealed the absence of conidiation. The induction of antifungal resistance in the susceptible strains to itraconazole, voriconazole, and amphotericin B increased after exposure to 12% CO₂ atmosphere and four weeks of incubation. The MIC values for itraconazole, voriconazole, and amphotericin B were 16 g/ml, 1 g/ml, and 16 g/ml, respectively. These values for the control group were 0.125 g/ml, 0.125 g/ml, and 2 g/ml, respectively.

Conclusion

Exposure to different CO₂ atmospheres induced morphological changes in A. fumigatus, it seems to increase the MIC values, as well. In parallel, resistance to both itraconazole and voriconazole was also observed.

Challenges in the Diagnosis of Invasive Fungal Infections in Immunocompromised Hosts

Purpose of review

The expanding population of immunocompromised patients coupled with the recognition of a growing number of different species of fungi responsible for diseases in such hosts makes the diagnosis of invasive fungal infection (IFI) a challenging task. The recent advances and challenges in the diagnosis of IFI in the setting of immunocompromised hosts are reviewed. The advantages and limitations of histopathology and the role of culture-independent methods, such as those based on the use of nucleic acids applied to fresh and formalin-fixed, paraffin-embedded sections, besides culture- and non-culture-based diagnostic methods, to obtain a timely and correct diagnosis of IFI are highlighted.

Recent findings

The therapeutic implications of identifying the genus and species of the fungus present in the specimen with the molecular diagnostics applied to tissue specimens are reviewed. No method alone is efficient in correctly identifying fungi and it is essential to combine the traditional histochemical staining with molecular methods to achieve a rapid and genus-/species-specific diagnosis of IFI.

Summary

We review the recent findings and challenges in the hystopathologic diagnosis of IFI in the setting of immunocompromised hosts. Non method alone is efficient in correctly identify fungi and pathologists should combine classic staining with molecular methods to achieve a rapid and genus/species fungal diagnosis.

Challenges and Solution of Invasive Aspergillosis in Non-neutropenic Patients: A Review

Invasive aspergillosis (IA) is a serious opportunistic infection, which has increasingly been recognized as an emerging disease of non-neutropenic patients. In this group of patients, the diagnosis of IA can be challenging owing to the lack of specificity of symptoms, the difficulty in discriminating colonization from infection, and the lower sensitivity of microbiological and radiological tests compared with immunocompromised patients. The aim of this article is to present to clinicians a critical review on the management of IA in non-neutropenic patients.

Nucleic acid amplification methodologies for the detection of pulmonary mold infections

INTRODUCTION

The detection of pulmonary mold infections has historically required technically demanding methods obtained through invasive procedures. Nucleic acid amplification assays have the potential to circumvent the technical hurdles associated with diagnosis, but are not without potential pitfalls. Areas covered: In this paper, the authors review new assays for the diagnosis of pulmonary mold infections due to aspergillosis, mucormycosis, and hyalohyphomycoses as well as uncommon infections caused by dematiaceous molds. Expert commentary: Nucleic acid amplification assays have the potential to rapidly identify patients with invasive mycoses and could shorten the time to implementation of appropriate antimicrobial therapy. However, selection of appropriate patient populations will be crucial to ensure the highest Bayesian positive predictive value for any novel diagnostic platform.

Special considerations for the diagnosis and treatment of invasive pulmonary aspergillosis

INTRODUCTION

The diagnosis and treatment of invasive pulmonary aspergillosis (IPA) are ongoing challenges in clinical practice. While important advances have recently been made, including enhanced diagnostic modalities as well as novel therapeutic and prophylactic options, more effective options are urgently needed as the population of immunocompromised patients continues to expand. Areas covered: In this paper, we review novel approaches to diagnosis of IPA, including multiplex PCR, Matrix Assisted Laser Desorption/Ionization-Time of Flight Mass Spectrometry and provide a detailed review of the extended-spectrum triazole isavuconazole, which was approved in 2015 to treat IPA. Expert commentary: We explore burgeoning approaches to diagnosis, including the lateral flow assay, volatile organic compounds, and artificial olfactory technology, as well as novel antifungal agents to treat IPA such as SCY-078 and F901318.

Molecular diagnosis of invasive mycoses of the central nervous system

INTRODUCTION

In September 2012, the Centers for Disease Control and Prevention (CDC) began investigating an outbreak of fungal meningitis among patients who had received contaminated preservative-free methyl prednisolone acetate injections from the New England Compounding Center in Framingham, Massachusetts. Thousands of patients were potentially exposed to tainted corticosteroids, but establishing the diagnosis of fungal meningitis during the nationwide outbreak was difficult because little was known about the natural history of the disease. Areas covered: The challenges associated with this outbreak highlighted the need for rapid and reliable methodologies to assist in the diagnosis of invasive mycoses of the central nervous system (IMCNS), which may be devastating and difficult to treat. In this paper, we review the causative agents of these potentially-lethal infections, which include cryptococcal meningitis, cerebral aspergillosis, and hematogenous Candida meningoencephalitis. Expert commentary: While microscopy, culture, and histopathologic identification of fungal pathogens remain the gold standard for diagnosis, new platforms and species-specific assays have recently emerged, including lateral flow immunoassays (LFA), matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS), and multiplex PCR in conjunction with magnetic resonance (MR) to potentially aid in the diagnosis of IMCNS.