ß-D-Glucan Assay in the Cerebrospinal Fluid for the Diagnosis of Non-cryptococcal Fungal Infection of the Central Nervous System: A Retrospective Multicentric Analysis and a Comprehensive Review of the Literature

BACKGROUND

Except for cryptococcosis, fungal infection of the central nervous system (FI-CNS) is a rare but severe complication. Clinical and radiological signs are non-specific, and the value of conventional mycological diagnosis is very low. This study aimed to assess the value of β1,3-D-glucan (BDG) detection in the cerebrospinal fluid (CSF) of non-neonatal non-cryptococcosis patients.

METHODS

Cases associated with BDG assay in the CSF performed in 3 French University Hospitals over 5 years were included. Clinical, radiological, and mycological results were used to classify the episodes as proven/highly probable, probable, excluded, and unclassified FI-CNS. Sensitivity and specificity were compared to that calculated from an exhaustive review of the literature.

RESULTS

In total, 228 episodes consisting of 4, 7, 177, and 40 proven/highly probable, probable, excluded, and unclassified FI-CNS, respectively, were analysed. The sensitivity of BDG assay in CSF to diagnose proven/highly probable/probable FI-CNS ranged from 72.7% [95% confidence interval {CI}: 43.4%‒90.2%] to 100% [95% CI: 51%‒100%] in our study and was 82% in the literature. For the first time, specificity could be calculated over a large panel of pertinent controls and was found at 81.8% [95% CI: 75.3%‒86.8%]. Bacterial neurologic infections were associated with several false positive results.

CONCLUSIONS

Despite its sub-optimal performance, BDG assay in the CSF should be added to the diagnostic armamentarium for FI-CNS.

Clinical characteristics of central nervous system candidiasis due to Candida albicans in children: a single-center experience

BACKGROUND

Central nervous system candidiasis due to Candida albicans (CNSC) in children is easily misdiagnosed and is associated with poor outcomes and a high mortality rate. There is no big data research or systematic review of CNSC.

METHODS

Patients diagnosed as CNSC with positive culture results of Candida albicans in Beijing Children's Hospital affiliated to Capital Medical University from March 2010 to March 2019 were included. Patients receiving immunosuppressive therapy or transplantation, or with malignant tumours were excluded. We analysed the clinical characteristics, follow-up results, drug susceptibility tests and whole-exome sequencing (WES) results.

RESULTS

Thirty-three definitive patients were enrolled, including 22 males and 11 females. Twenty-five patients suffered from CNSC when they were less than 1 year old, and a total of 29 patients had high-risk factors. The main clinical manifestations were fever, convulsions, and positive neurological signs. Twenty-two patients had CNS infections alone, and 11 patients had CNS infections combined with invasive infections involving multiple sites. Twenty-seven cases had a positive CSF and/or blood culture at our hospital. All strains were susceptible to fluconazole, and 2 strains had intermediate susceptibility to voriconazole. As for amphotericin B, all the strains were wild type (WT). WES of 16 patients revealed 2 cases with CARD9 mutations, who suffered from recurrent onychomycosis or thrush before.

CONCLUSION

CNSC mostly existed in children younger than 1 year old, who all had underlying risk factors. CNSC patients with onset at an older age or with recurrent superficial fungal infections might have primary immunodeficiency.

Risk Prediction of Central Nervous System Infection Secondary to Intraventricular Drainage in Patients with Intracerebral Hemorrhage: Development and Evaluation of a New Predictive Model Nomogram

BACKGROUND

Currently no reliable tools are available for predicting the risk of central nervous system (CNS) infections in patients with intracerebral hemorrhage after undergoing ventriculostomy drainage. The current study sought to develop and validate a nomogram to identify high-risk factors of CNS infection after ventriculomegaly drain placement for intracerebral hemorrhage.

METHODS

A total of 185 patients with intracerebral hemorrhage who underwent ventriculoperitoneal drainage were enrolled to the current study. Patients were divided into a CNS infection group (20 patients) and a non-CNS infection group (165 patients). The baseline data from both groups was used to develop and evaluate a model for predicting the likelihood of developing CNS infection after ventriculoperitoneal drain placement for intracerebral hemorrhage.

RESULTS

The finding showed that operative time, intraventricular drainage duration, postoperative temperature, white blood cell count in cerebrospinal fluid (CSF), neutrophils ratio in CSF, Red blood cell count in CSF, and glucose content in CSF were correlated with CNS infection. A nomogram for predicting the risk of CNS infection was constructed based on these variables. The c-index and the AUC of the ROC curve was 0.961, showing good discrimination. Clinical decision curve analysis indicated that the nomogram clinical application ranged between 1 and 100%. The clinical impact curve was generated to set with a threshold probability of 0.5.

CONCLUSION

The nomogram reported in the current study can be used by clinicians to identify patients likely to have secondary CNS infections, so that clinicians can better treat these patients at earlier stages.

Neuroinfectious Disease Emergencies

Neuroinfectious diseases can affect immunocompetent and immunosuppressed individuals and cause a variety of emergencies including meningitis, encephalitis, and abscess. Neurologic infections are frequently complicated by secondary injuries that also present emergently such as cerebrovascular disease, acute obstructive hydrocephalus, and seizure. In most cases, timely recognition and early treatment of infection can improve the morbidity and mortality of infectious neurologic emergencies.

Cell wall polysaccharides from pathogenic fungi for diagnosis of fungal infectious disease

Invasive fungal diseases are associated with significant morbidity and mortality, particularly in immunocompromised individuals. Early and accurate diagnosis is crucial for effective treatment. Despite traditional methods such as microbiological culture, histopathology, radiology and direct microscopy are available, antigen/antibody-based diagnostics are emerging for diagnosis of invasive fungal infections (IFI). Fungal cell wall is a unique structure composed of polysaccharides that are well correlated with fungal burden during fungal infections. Based on this feature, cell wall polysaccharides have been explored as antigens in IFIs diagnostics such as the galactomannan assay, mannan test, β-glucan assay and cryptococcal CrAg test. Herein, we provide an overview on the cell wall polysaccharides from three opportunistic pathogens: Aspergillus fumigatus, Candida albicans and Cryptococcus neoformans, and their applications for IFIs diagnosis. The clinical outcome of newly developed cell wall polysaccharides-based diagnostics is also discussed.

Efficacy of Cerebrospinal Fluid Beta-d-Glucan Diagnostic Testing for Fungal Meningitis: a Systematic Review

Several case reports and cohort studies have examined the use of (1,3)-beta-d-glucan measurement with cerebrospinal fluid to diagnose fungal meningitis. This systematic review aims to characterize the evidence regarding cerebrospinal fluid (1,3)-beta-d-glucan measurement to detect fungal meningitis. We searched PubMed for (1,3)-beta-d-glucan and each of several distinct fungi, cerebrospinal fluid, and meningitis. Summary data including diagnostic performance (where applicable) were recorded. A total of 939 records were examined via a PubMed search. One hundred eighteen records remained after duplicates were removed, and 104 records were excluded, as they did not examine cerebrospinal fluid, included animals, or focused on nonfungal infections. Fourteen studies were included in this systematic review. A variety of fungi, including species of Candida, Aspergillus, Exserohilum, Cryptococcus, Histoplasma, and Coccidioides, were studied, although most were case reports. Diagnostic accuracy was examined in 5 studies. Cerebrospinal fluid (CSF) (1,3)-beta-d-glucan measurement showed >95% sensitivity in the corticosteroid injection-related outbreak of Exserohilum rostratum One study in Histoplasma meningitis found 53% (53/87) sensitivity and 87% (133/153) specificity, while another study of Cryptococcus meningitis found 89% (69/78) sensitivity and 85% (33/39) specificity. CSF (1,3)-beta-d-glucan testing may be useful, primarily as a nonspecific marker of fungal meningitis. Although the FDA black box warning states that Cryptococcus spp. do not make (1,3)-beta-d-glucan, the current evidence shows that (1,3)-beta-d-glucan is detectable in cryptococcal meningitis. Organism-specific testing should be used in conjunction with (1,3)-beta-d-glucan measurement.

Fungal infections of the central nervous system and paranasal sinuses in onco-haematologic patients. Epidemiological study reporting the diagnostic-therapeutic approach and outcome in 89 cases

Invasive fungal infections (IFI) of the Central Nervous System (IFI-CNS) and Paranasal Sinuses (IFI-PS) are rare, life-threatening infections in haematologic patients, and their management remains a challenge despite the availability of new diagnostic techniques and novel antifungal agents. In addition, analyses of large cohorts of patients focusing on these rare IFI are still lacking. Between January 2010 and December 2016, 89 consecutive cases of Proven (53) or Probable (36) IFI-CNS (71/89) and IFI-PS (18/89) were collected in 34 haematological centres. The median age was 40 years (range 5-79); acute leukaemia was the most common underlying disease (69%) and 29% of cases received a previous allogeneic stem cell transplant. Aspergillus spp. were the most common pathogens (69%), followed by mucormycetes (22%), Cryptococcus spp. (4%) and Fusarium spp. (2%). The lung was the primary focus of fungal infection (48% of cases). The nervous system biopsy was performed in 10% of IFI-CNS, and a sinus biopsy was performed in 56% of IFI-PS (P = 0.03). The Galactomannan test on cerebrospinal fluid has been performed in 42% of IFI-CNS (30/71), and it was positive in 67%. Eighty-four pts received a first-line antifungal therapy with Amphotericine B in 58% of cases, Voriconazole in 31% and both in 11%. Moreover, 58% of patients received 2 or more lines of therapy and 38% were treated with a combination of 2 or more antifungal drugs. The median duration of antifungal therapy was 60 days (range 5-835). A surgical intervention was performed in 26% of cases but only 10% of IFI-CNS underwent neurosurgical intervention. The overall response rate to antifungal therapy (complete or partial response) was 57%, and 1-year overall survival was 32% without significant differences between IFI-CNS and IFI-PS. The overall mortality was 69% but the IFI attributable mortality was 33%. Mortality of IFI-CNS/PS remains high but, compared to previous historical data, it seems to be reduced probably due to the availability of newer antifungal drugs. The results arising from this large contemporary cohort of cases may allow a more effective diagnostic and therapeutic management of these very rare IFI complications in haematologic patients.

Detection of (1,3)-β-d-Glucan in Cerebrospinal Fluid in Histoplasma Meningitis

The diagnosis of central nervous system (CNS) histoplasmosis is often difficult. Although cerebrospinal fluid (CSF) (1,3)-β-d-glucan (BDG) is available as a biological marker for the diagnosis of fungal meningitis, there are limited data on its use for the diagnosis of Histoplasma meningitis. We evaluated CSF BDG detection, using the Fungitell assay, in patients with CNS histoplasmosis and controls. A total of 47 cases and 153 controls were identified. The control group included 13 patients with a CNS fungal infection other than histoplasmosis. Forty-nine percent of patients with CNS histoplasmosis and 43.8% of controls were immunocompromised. The median CSF BDG level was 85 pg/ml for cases, compared to <31 pg/ml for all controls (P < 0.05) and 82 pg/ml for controls with other causes of fungal meningitis (P = 0.27). The sensitivity for detection of BDG in CSF was 53.2%, whereas the specificity was 86.9% versus all controls and 46% versus other CNS fungal infections. CSF BDG levels of ≥80 pg/ml are neither sensitive nor specific to support a diagnosis of Histoplasma meningitis.

Innate Immune and Fungal Model of Alzheimer's Disease

Various fungi and bacteria can colonize in the brain and produce physical alterations seen in Alzheimer’s disease (AD). Environmental and genetic factors affect the occurrence of fungal colonization, and how fungi can grow, enter the brain, and interact with the innate immune system. The essence of AD development is the defeat of the innate immune system, whether through vulnerable patient health status or treatment that suppresses inflammation by suppressing the innate immune system. External and mechanical factors that lead to inflammation are a door for pathogenic opportunity. Current research associates the presence of fungi in the etiology of AD and is shown in cerebral tissue at autopsy. From the time of the discovery of AD, much speculation exists for an infective cause. Identifying any AD disease organism is obscured by processes that can take place over years. Amyloid protein deposits are generally considered to be evidence of an intrinsic response to stress or imbalance, but instead amyloid may be evidence of the innate immune response which exists to destroy fungal colonization through structural interference and cytotoxicity. Fungi can remain ensconced for a long time in niches or inside cells, and it is the harboring of fungi that leads to repeated reinfection and slow wider colonization that eventually leads to a grave outcome. Although many fungi and bacteria are associated with AD affected tissues, discussion here focuses on Candida albicans as the archetype of human fungal pathology because of its wide proliferation as a commensal fungus, extensive published research, numerous fungal morphologies, and majority proliferation in AD tissues.

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.

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.

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.

Cerebrospinal Fluid (1,3)-Beta-d-Glucan Testing Is Useful in Diagnosis of Coccidioidal Meningitis

Diagnosing coccidioidal meningitis (CM) can be problematic owing to its infrequency and/or a delay in the positivity of a cerebrospinal fluid (CSF) culture or CSF antibody, particularly if the primary coccidioidal infection is unrecognized. We tested 37 CSF specimens, 26 from patients with confirmed CM and 11 from patients with suspected microbial meningitis without fungal diagnosis, for (1,3)-beta-glucan (BG). BG in CM CSF specimens ranged from 18 to 3,300 pg/ml and in controls ranged from <3.9 to 103 pg/ml. Diagnostic performance was determined using a 31-pg/ml cutoff (the bottom of the serum range according to the directions for the commercial kit, although further serial dilutions of the standard indicated linearity to 3.9). Sensitivity was 96%, specificity was 82%, positive and negative predictive values were 93% and 90%, and the area under the receiver operating characteristic curve was 0.937. Fifteen of 15 samples of >103 pg/ml were CM. The one false-negative specimen was from a patient with a pseudosyrinx, without inflammatory evidence of meningitis activity. Serial samples from some patients were positive at ≤8 years, indicating no loss of positivity with chronicity. Samples stored frozen since 2000 included those with 2 of the 3 highest values, indicating that fresh samples not required. A previous study indicated serum sensitivities of 53% in acute, 50% in resolved, and 83% in disseminated and meningeal coccidioidomycosis. Three studies of other fungal meningitides ranged from 86 to 1,524 pg/ml CSF, with 37 controls of <4 to 115 pg/ml CSF. CSF BG analysis had good diagnostic performance in CM. CSF BG testing can be useful in CM, and a commercial kit is available. It will be of interest to correlate this with course, treatment, outcome, inflammation, and antigen. The only mycoses with common central nervous system (CNS) involvement are cryptococcal and coccidioidal, so CSF BG screening can be useful in meningitis diagnosis.

Voriconazole treatment of Candida tropicalis meningitis: persistence of (1,3)-β-D-glucan in the cerebrospinal fluid is a marker of clinical and microbiological failure: A case report

INTRODUCTION

Infections are still the most common complications of cerebral shunt procedures. Even though fungal etiologies are considered to be rare, they are associated with significant morbidity and mortality. Due to their uncommonness, diagnostic procedures and optimal therapy are poorly defined. We report a case of Candida tropicalis infection of ventriculo-peritoneal cerebrospinal fluid (CSF) shunt in a 49-year-old immune competent male treated with voriconazole (VOR).

METHODS

Microbiological and CSF markers (1,3-b-D-glucan-BDG) of fungal infection, biofilm production capacity, sensitivity of serial isolates of the pathogen, and the concentration of the antifungal drug have been monitored and related to the clinical course of this infection.

RESULTS

Despite appropriate treatment with VOR, in terms of adequate achieved CSF drug concentrations and initial effective therapeutic response, loss of VOR susceptibility of the C tropicalis and treatment failure were observed.

CONCLUSION

Biofilm production of the C. tropicalis isolate might have had a significant role in treatment failure. Of interest, clinical and microbiological unfavorable outcome was anticipated by persistence of BDG in CSF. Rising titers of this marker were associated with relapse of fungal infection.

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.

CNS infections in patients with hematological disorders (including allogeneic stem-cell transplantation)-Guidelines of the Infectious Diseases Working Party (AGIHO) of the German Society of Hematology and Medical Oncology (DGHO)

Diagnosis of CNS infections remains a great challenge in patients with hematological disorders since symptoms might both be masked and be mimicked by other conditions such as metabolic disturbances or consequences from antineoplastic treatment. Thus, awareness of this complication is crucial and any suspicion of a CNS infection should lead to timely and adequate diagnostics and treatment to improve the outcome in this population.

Infections of the central nervous system (CNS) are infrequently diagnosed in immunocompetent patients, but they do occur in a significant proportion of patients with hematological disorders. In particular, patients undergoing allogeneic hematopoietic stem-cell transplantation carry a high risk for CNS infections of up to 15%. Fungi and Toxoplasma gondii are the predominant causative agents. The diagnosis of CNS infections is based on neuroimaging, cerebrospinal fluid examination and biopsy of suspicious lesions in selected patients. However, identification of CNS infections in immunocompromised patients could represent a major challenge since metabolic disturbances, side-effects of antineoplastic or immunosuppressive drugs and CNS involvement of the underlying hematological disorder may mimic symptoms of a CNS infection. The prognosis of CNS infections is generally poor in these patients, albeit the introduction of novel substances (e.g. voriconazole) has improved the outcome in distinct patient subgroups. This guideline has been developed by the Infectious Diseases Working Party (AGIHO) of the German Society of Hematology and Medical Oncology (DGHO) with the contribution of a panel of 14 experts certified in internal medicine, hematology/oncology, infectious diseases, intensive care, neurology and neuroradiology. Grades of recommendation and levels of evidence were categorized by using novel criteria, as recently published by the European Society of Clinical Microbiology and Infectious Diseases.

Clinical Practice Guideline for the Management of Candidiasis: 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.

Chronic Invasive Aspergillus Sinusitis and Otitis with Meningeal Extension Successfully Treated with Voriconazole

Invasive aspergillosis (IA) is a severe disseminated fungal disease that occurs mostly in immunocompromised patients. However, central nervous system IA, combining meningitis and skull base involvement, does not occur only in groups with classic risk factors for IA; patients with chronic renal failure and diabetes mellitus are also at risk for more chronic forms. In both of our proven IA cases, voriconazole monotherapy was effective without surgery, and cerebrospinal fluid and serum 1,3-β-d-glucan test results were initially positive, in contrast to galactomannan antigen results.

Methods of rapid diagnosis for the etiology of meningitis in adults

Infectious meningitis may be due to bacterial, mycobacterial, fungal or viral agents. Diagnosis of meningitis must take into account numerous items of patient history and symptomatology along with regional epidemiology and basic cerebrospinal fluid testing (protein, etc.) to allow the clinician to stratify the likelihood of etiology possibilities and rationally select additional diagnostic tests. Culture is the mainstay for diagnosis in many cases, but technology is evolving to provide more rapid, reliable diagnosis. The cryptococcal antigen lateral flow assay (Immuno-Mycologics) has revolutionized diagnosis of cryptococcosis and automated nucleic acid amplification assays hold promise for improving diagnosis of bacterial and mycobacterial meningitis. This review will focus on a holistic approach to diagnosis of meningitis as well as recent technological advances.

Detection of High Cerebrospinal Fluid Levels of (1→3)-β-d-Glucan in Cryptococcal Meningitis

(1→3)-Beta-D-glucan was detected in high levels in cerebrospinal fluid, and to lesser extent in serum, among HIV-infected persons with cryptococcal meningitis.

Background

 (1→3)-β-d-Glucan (BDG) is a helpful diagnostic marker for many invasive fungal infections. However, BDG is not thought to be useful in diagnosing cryptococcosis. We evaluated the utility of BDG as an adjunct diagnostic tool for patients infected with human immunodeficiency virus (HIV) and presenting with suspected cryptococcal meningitis.

Methods

 The Fungitell assay was used to measure BDG concentrations in cerebrospinal fluid (CSF) (n = 177) and serum (n = 109) of HIV-infected Ugandans and South Africans with suspected meningitis. Correlations between BDG concentrations and quantitative CSF cryptococcal cultures, CSF cryptococcal antigen (CRAG) titers, and 18 different CSF cytokine concentrations were assessed using non-parametric tests. Mixed models evaluated longitudinal changes in CSF BDG concentrations. Survival analyses were used to evaluate BDG's relationship with mortality.

Results

 The Fungitell BDG assay provided 89% sensitivity and 85% specificity in CSF for cryptococcal meningitis. Serum sensitivity was suboptimal (79%). Cerebrospinal fluid BDG concentrations at diagnosis were median (interquartile range) 343 (200–597) pg/mL in cryptococcal patients and 37 (23–46) pg/mL in patients without cryptococcosis. Sensitivity in CSF improved to 98% (53 of 54) when initial fungal burdens were ≥10 000 colony-forming units/mL. (1→3)-β-d-Glucan normalized rapidly after initiating antifungal therapy. Baseline BDG concentrations correlated with CSF fungal burden (rho = 0.820; P < .001), CSF CRAG lateral flow assay titers (rho = 0.780, P < .001), and monocyte chemotactic protein-1 levels in CSF (P = .047). In patients with cryptococcal meningitis, BDG ≥500 pg/mL at diagnosis was associated with increased 10-week mortality.

Conclusions

 (1→3)-β-d-Glucan is detectable in the CSF of HIV-infected patients with Cryptococcus, and it may provide useful prognostic information. Sensitivity is less than CRAG; however, BDG normalizes rapidly, unlike CRAG, making BDG potentially useful in diagnosing recurrent episodes.

Non-cultural methods for the diagnosis of invasive fungal disease

Invasive fungal diseases carry a high mortality risk which can be reduced by early treatment. Diagnosing invasive fungal diseases is challenging, because invasive methods for obtaining histological samples are frequently not feasible in thrombocytopenic immunocompromised patients, while fungal cultures have low sensitivity and a long turn-around time. Non-cultural methods are fundamental for a rapid diagnosis of invasive fungal diseases and they include assays based on the detection of fungal antigens (galactomannan, Aspergillus-lateral flow device, [1,3]-β-D-glucan, mannan), antibodies, such as anti-mannan, and molecular tests. With the exception of some molecular methods for rare fungi, the non-cultural assays are usually applied to the diagnosis of invasive aspergillosis, invasive candidiasis and pneumocystosis. The performance of a single test or a combination of tests will be discussed, with particular focus on choosing the most appropriate marker(s) for every specific patient population. Reasons for potential false-positive or false-negative results will be discussed.

Utility of measuring (1,3)-β-d-glucan in cerebrospinal fluid for diagnosis of fungal central nervous system infection

(1-3)-β-d-Glucan (BDG) from cerebrospinal fluid (CSF) is a promising marker for diagnostic and prognostic aid of central nervous system (CNS) fungal infection, but its relationship to serum values has not been studied. Herein, we detected BDG from CSF at levels 2-fold lower than those in serum in patients without evidence of fungal disease but 25-fold higher than those in in serum in noncryptococcal CNS fungal infections. CSF BDG may be a useful biomarker in the evaluation of fungal CNS disease.

Cerebral aspergillosis in a patient with leprosy and diabetes: a case report

Background

Opportunistic fungi are dispersed as airborne, ground and decaying matter. The second most frequent extra-pulmonary disease by Aspergillus is in the central nervous system.

Case presentation

The case subject was 55 years old, male, mulatto, and an assistant surveyor residing in Teresina, Piauí. He presented with headache, seizures, confusion, fever and left hemiparesis upon hospitalization in 2006 at Hospital São Marcos. Five years previously, he was diagnosed with diabetes mellitus, and 17 months previously he had acne margined by hyperpigmented areas and was diagnosed with leprosy. Laboratory tests indicated leukocytosis and magnetic resonance imaging showed an infarction in the right cerebral hemisphere. Cerebrospinal fluid examination showed 120 cells/mm³ and was alcohol-resistant bacilli negative. Trans-sphenoidal surgery with biopsy showed inflammation was caused by infection with Aspergillus fumigatus. We initiated use of parenteral amphotericin B, but his condition worsened. He underwent another surgery to implant a reservoir of Ommaya–Hickmann, a subcutaneous catheter. We started liposomal amphotericin B 5 mg/kg in the reservoir on alternate days. He was discharged with a prescription of tegretol and fluconazole.

Conclusion

This report has scientific interest because of the occurrence of angioinvasive cerebral aspergillosis in a diabetic patient, which is rarely reported. In conclusion, we suggest a definitive diagnosis of cerebral aspergillosis should not postpone quick effective treatment.

Serum 1,3-beta-d-glucan for antifungal treatment stratification at the intensive care unit and the influence of surgery

The purpose of this study was to evaluate a preemptive approach with serum 1,3-beta-d-glucan (BDG) as a marker for treatment stratification of systemic antifungal (AF) therapy in patients with clinical suspected invasive fungal infections (IFI) at intensive care units (ICU), and the impact of surgical procedures. A total of 66 ICU patients with clinical suspected IFI were included in this retrospective analysis. Serum BDG testing was performed prior to initiation of AF treatment and in addition to routine diagnostic measures. Based on the BDG results the initial clinical decision whether or not to start systemic AF therapy was re-evaluated. Impact of surgical procedures on clinical utility of serum BDG was evaluated in a sub-group of 25 patients who had undergone surgical procedures prior to BDG evaluation. BDG test results led to discontinuation of AF therapy in 13 patients, and initiation of AF therapy in seven patients. In 46 patients the clinical decision was confirmed by BDG. The majority of suspected, probable and proven IFI cases (10/13, 77%) was predicted by the test. BDG testing turned out positive in 9/25 (36%) of patients that had undergone recent surgery and levels correlated with clinical findings. Serum BDG evaluation seems to be a promising tool to guide AF therapy in ICU patients even after recent surgical procedures.

Mold infections of the central nervous system

The recent outbreak of exserohilum rostratum meningitis linked to epidural injections of methylprednisolone acetate has brought renewed attention to mold infections of the central nervous system (CNS). Although uncommon, these infections are often devastating and difficult to treat. This focused review of the epidemiologic aspects, clinical characteristics, and treatment of mold infections of the CNS covers a group of common pathogens: aspergillus, fusarium, and scedosporium species, molds in the order Mucorales, and dematiaceous molds. Infections caused by these pathogen groups have distinctive epidemiologic profiles, clinical manifestations, microbiologic characteristics, and therapeutic implications, all of which clinicians should understand.

Resolution of a fungal mycotic aneurysm after a contaminated steroid injection: a case report

BACKGROUND

In the past ten years there have been three separate outbreaks of fungal contaminated steroid injections from compounding pharmacies. The 2012 outbreak of central nervous system fungal infections associated with contaminated methylprednisolone produced by a United States compounding pharmacy has led to 750 infections (151 with meningitis and paraspinal infections and 325 cases with paraspinal infections without meningitis) and 64 deaths as of October 23, 2013. Exserohilum rostratum has been the predominant pathogen identified by culture, polymerase chain reaction or antibody tests. According to previous reports, cerebral involvement with phaeohyphomycosis has a high risk of morbidity and mortality.

CASE PRESENTATION

We report a 41 year-old Caucasian woman who received a lumbar methylprednisolone injection from a contaminated lot in August 2012. She was diagnosed with fungal meningitis by cerebrospinal fluid pleocytosis and positive (1, 3) beta-D-glucan after cultures and polymerase chain reaction were negative. Two weeks after onset of therapy, she developed a 4.1 mm superior cerebellar artery mycotic aneurysm associated with new stroke symptoms, which resolved with thirty-two weeks of antifungal treatment.

CONCLUSIONS

This is the rare case report of successful medical management of a cerebral mycotic aneurysm with stroke symptoms related to a presumed phaeohyphomycosis in an immunocompetent individual. Further studies are needed to determine the utility of cerebrospinal fluid (1, 3) beta-D-glucan in diagnosing and monitoring patients with meningitis thought to be related to fungal infection.

Fungal central nervous system infections: prevalence and diagnosis

Fungal infections of the central nervous system (CNS) are rare but they pose a significant challenge. Their prevalence spans a wide array of hosts including immunosuppressed and immunocompetent individuals, patients undergoing neurosurgical procedures and those carrying implantable CNS devices. Cryptococcus neoformans and Aspergillus spp. remain the most common pathogens. Magnetic resonance imaging can help localize the lesions, but diagnosis is challenging since invasive procedures may be needed for the retrieval of tissue, especially in cases of fungal abscesses. Antigen and antibody tests are available and approved for use in the cerebrospinal fluid (CSF). PCR-based techniques are promising but they are not validated for use in the CSF. This review provides an overview on the differential diagnosis of the fungal CNS disease based on the host and the clinical syndrome and suggests the optimal use of diagnostic techniques. It also summarizes the emergence of Cryptococcus gatti and an unanticipated outbreak caused by Exserohilum rostratum.

Utility of (1-3)-β-D-glucan testing for diagnostics and monitoring response to treatment during the multistate outbreak of fungal meningitis and other infections

BACKGROUND

 The 2012 outbreak of fungal meningitis associated with contaminated methylprednisolone produced by a compounding pharmacy has resulted in >750 infections. An important question facing patients and clinicians is the duration of antifungal therapy. We evaluated (1-3)-β-d-glucan (BDG) as a marker for monitoring response to treatment.

METHODS

 We determined sensitivity and specificity of BDG testing using the Fungitell assay, by testing 41 cerebrospinal fluid (CSF) specimens from confirmed cases of fungal meningitis and 66 negative control CSF specimens. We also assessed whether BDG levels correlate with clinical status by using incident samples from 108 case patients with meningitis and 20 patients with serially collected CSF.

RESULTS

 A cutoff value of 138 pg/mL provided 100% sensitivity and 98% specificity for diagnosis of fungal meningitis in this outbreak. Patients with serially collected CSF were divided into 2 groups: those in whom BDG levels declined with treatment and those in whom BDG remained elevated. Whereas most patients with a decline in CSF BDG had clinical improvement, all 3 patients with continually elevated BDG had poor clinical outcomes (stroke, meningitis relapse, or development of new disease).

CONCLUSIONS

 Our data suggest that measuring BDG in CSF is a highly sensitive test for diagnosis of fungal meningitis in this outbreak. Analysis of BDG levels in serially collected CSF demonstrated that BDG may correlate with clinical response. Routine measurement of BDG in CSF may provide useful adjunctive data for the clinical management of patients with outbreak-associated meningitis.

CNS Mold Infections

Mold infections of the central nervous system (CNS) present as abscesses, infarcts, hemorrhages, and, less commonly, meningitis. These invasive infections are difficult both to identify and to eradicate given low-sensitivity diagnostics and high-toxicity, low-efficacy antifungal therapies, hence resulting in high rates of morbidity and mortality. Herein, the recent literature on CNS mold infections is reviewed, and updates in diagnosis and management are discussed.