CNS aspergillosis: recognition, diagnosis and management

Cerebrospinal fluid galactomannan detection for the diagnosis of central nervous system aspergillosis: a diagnostic test accuracy systematic review and meta-analysis

BACKGROUND

Cerebrospinal fluid (CSF) galactomannan is an adjunctive test for central nervous system (CNS) aspergillosis diagnosis with unclear diagnostic test characteristics.

OBJECTIVES

To evaluate the diagnostic test characteristics of CSF galactomannan in CNS aspergillosis.

METHODS

Systematic review and meta-analysis.

DATA SOURCES

MEDLINE, Embase, Web of Science, and Scopus, from inception to 24 February 2023.

STUDY ELIGIBILITY CRITERIA

Prospective and retrospective studies with 1-group and 2-group designs using any galactomannan assay on CSF to diagnose CNS aspergillosis.

PARTICIPANTS

Adult and/or paediatric patients with CNS aspergillosis.

TEST(S)

Galactomannan testing on CSF specimens.

REFERENCE STANDARD

European Organization for Research and Treatment of Cancer and the Mycoses Study Group Education and Research Consortium (EORTC/MSGERC) diagnostic criteria, or equivalent.

ASSESSMENT OF RISK OF BIAS

QUADAS-2 assessment in duplicate.

METHODS OF DATA SYNTHESIS

Bivariate restricted maximum likelihood estimation random-effects meta-analysis, summarized using forest and summary receiver operating characteristic plots; bivariate meta-regression models to investigate heterogeneity; and subgroup and sensitivity analyses to explore subgroup effects and methodologic choices (PROSPERO registration: CRD42022296331; funding: none).

RESULTS

We included eight studies (n = 342 participants). The summary estimates of CSF galactomannan sensitivity and specificity were 69.0% (95% CI, 57.2-78.7%) and 94.4% (95% CI, 82.8-98.3%), respectively. Using meta-regression, galactomannan cut-off (p = 0.38), EORTC/MSGERC criteria version (p = 0.48), or whether the reference standard was defined as both proven and probable or only proven aspergillosis (p = 0.48) did not explain observed heterogeneity. No subgroup effects were demonstrated by analysing the EORTC/MSGERC criteria reference standard used (e.g. 2002 vs. 2008 definitions) or whether paediatric patients were included. Diagnostic sensitivity was improved using a galactomannan cut-off of 1.0, and by excluding high risk of bias and 1-group design studies.

DISCUSSION

CSF galactomannan is a highly specific but insensitive test for use as a component of CNS aspergillosis diagnosis. Few included studies, no prospective studies, and a high risk of bias are study limitations.

Imaging Findings in Aspergillosis: From Head to Toe

Aspergillosis is a mycotic infection induced by airborne fungi that are ubiquitous. Inhalation of Aspergillus conidia results in transmission through the respiratory tract. The clinical presentation is dependent on organism and host specifics, with immunodeficiency, allergies, and preexisting pulmonary disease constituting the most important risk factors. In recent decades, the incidence of fungal infections has increased dramatically, due in part to the increased number of transplants and the pervasive use of chemotherapy and immunosuppressive drugs. The spectrum of clinical manifestations can range from an asymptomatic or mild infection to a swiftly progressive, life-threatening illness. Additionally, invasive infections can migrate to extrapulmonary sites, causing infections in distant organs. Recognition and familiarity with the various radiological findings in the appropriate clinical context are essential for patient management and the prompt initiation of life-saving treatment. We discuss the radiological characteristics of chronic and invasive pulmonary aspergillosis, as well as some of the typically unexpected extrapulmonary manifestations of disseminated disease.

Immunosuppressive Therapy in Solid Organ Transplantation: Primer for Radiologists and Potential Complications

The availability of effective immunosuppressive medication is primarily responsible for the dramatic improvement in long-term graft survival rates after solid organ transplantation. The commonly used drugs include monoclonal/polyclonal antibodies, corticosteroids, calcineurin inhibitors (cyclosporine and tacrolimus), antimetabolites, mammalian target of rapamycin, and many novel drugs. Prolonged immunosuppression is accompanied by several well-described potentially life-threatening complications. In addition to drug-related side effects, recipients of solid organs are unavoidably at a higher risk for infections and malignancies. Select infections and malignancies in solid organ transplant patients have distinctive imaging findings, and radiologists play a crucial role in the timely diagnosis and management of these conditions.

Disseminated Aspergillosis in a Patient With Neurosarcoidosis: Persistent Contrast Enhancement in CNS Despite Prolonged Antifungal Treatment: A Case Report

A 56-year-old Caucasian man was diagnosed with definite neurosarcoidosis after he presented with progressive bilateral lower extremity weakness and dysesthesia. He was started on a combination immunosuppressant regimen of dexamethasone, methotrexate and infliximab. Two months into treatment with immunosuppressants, he developed devastating disseminated aspergillosis which clinically stabilized with aggressive antifungal treatment however had a protracted radiological course despite prolonged anti-fungal treatment for over two years. Interestingly, he remained in remission from neurosarcoidosis off immunosuppression during the same period. This case emphasizes need for vigilance for fungal infections in patients treated with combination immunosuppressive therapy particularly TNF-α inhibitors such as infliximab.

Case Report and Clinical Reasoning: Fulminant Liver Failure and Invasive Aspergillosis Following Ocrelizumab Treatment in a 21 Year-Old Woman

We present the case of a 21 year-old woman with newly diagnosed relapsing-remitting multiple sclerosis who is given a single dose of ocrelizumab and placed on moderate-dose steroids with subsequent development of hepatic failure who goes on to develop highly fulminant systemic and central nervous system (CNS) aspergillosis. Ocrelizumab has no documented association with aspergillus infection, and moderate-dose steroids less often lead to such fulminant disease, but liver failure is associated with often-fatal aspergillus infection. We emphasize that liver failure is an underrecognized immune dysregulated state that predisposes to bacterial and fungal infections and suggest changes in diagnostic reasoning that could be considered in patients with multiple modalities of immunosuppression.

Invasive aspergillosis in the patient with focal segmental glomerulosclerosis initiating hemodialysis: a case report and mini-review

Background

Invasive aspergillosis (IA) is a severe form of fungal infection caused by the genus Aspergillus in immunocompromised hosts and has a high mortality rate. End-stage kidney disease (ESKD) is one of the risk factors for developing fungal infection; however, the detailed clinical and treatment course of ESKD patients with IA has been scarcely reported, especially for the patient initiating hemodialysis (HD). Here, we experienced a patient under immunosuppressive therapy for focal segmental glomerulosclerosis (FSGS) who suffered from IA involving lung and brain and resulted in initiating HD.

Case presentation

A 66-year-old male patient with a history of suspected non-tuberculosis mycobacterial lung disease was initially admitted to the hospital with minimal change disease and subsequently diagnosed as FSGS with worsening urinary protein levels. The combined treatment including immunosuppressive treatments of cyclosporin and glucocorticoids and low-density lipoprotein apheresis was initiated, and then, he experienced the symptoms of dry cough, somnolence, and disorientation, which were subsequently diagnosed as IA involving lung and brain. The patient required renal replacement therapy, and maintenance HD was continued. Despite the intensive treatment with multiple antifungals of liposomal amphotericin B, voriconazole, micafungin, and amphotericin B, the pneumonia of the patient did not improve, and he subsequently passed away.

Conclusions

We report the case of the IA under immunosuppressive treatment, who was subsequently initiated maintenance HD. The detailed clinical course of medications used to treat the patient is presented with the literature review of IA in ESKD and HD patients and those with past acid-fast bacterial infections. The careful determination of the intensity of immunosuppression and monitoring of the patient’s symptoms and early definitive diagnosis is crucial in treating IA in immunocompromised hosts with ESKD or in HD under immunosuppressive treatment, as the mortality for these patients is suspected to be high despite the intensive treatment.

Isavuconazole Treatment of Spinal Cord Invasive Aspergillosis Guided by Cerebrospinal Fluid (1,3)-β-d-Glucan Levels in a Patient with Low Interferon-Gamma and Ulcerative Colitis

This case highlights the use of (1,3)-beta-d glucan to direct treatment of a cervical spinal cord Aspergillus fumigatus infection in a 22-year-old woman immunocompromised due to steroid and anti-TNF therapy in the context of ulcerative colitis and interferon gamma deficiency. A 4-year treatment course requiring neurosurgical intervention on four occasions and prolonged antifungal therapy, including isavuconazole, resulted in clinical cure with a corresponding decrease in CSF beta-d-glucan to <30 pg/mL. Serum and CSF galactomannan levels were not elevated at any point during the clinical course.

Metagenomic Next-Generation Sequencing of Cerebrospinal Fluid for the Diagnosis of Cerebral Aspergillosis

Purpose: Cerebral aspergillosis (CA) is a rare but often fatal, difficult-to-diagnose, opportunistic infection. The utility of metagenomic next-generation sequencing (mNGS) for diagnosis of CA is unclear. We evaluated the usefulness of mNGS of the cerebrospinal fluid (CSF) for the diagnosis of CA. Methods: This prospective study involved seven consecutive patients with confirmed CA in whom CSF mNGS was performed. Serum (1→3)-β-D-glucan and galactomannan levels were determined, and histopathological examination and mNGS of the CSF were conducted. CSF specimens from three non-infected patients were used as positive controls. Results: mNGS of the CSF was positive in six of the seven confirmed CA cases (85.71% sensitivity). In the cryptococcal meningitis group (control), mNGS of the CSF was positive for Aspergillus in two patients (84.62% specificity). The positive likelihood ratio, negative likelihood ratio, and Youden's index of mNGS for CA in the CSF were 5.565, 0.169, and 0.7, respectively. Among the six mNGS-positive cases, more than two Aspergillus species were found in four (4/6, 66.67%). In the positive controls, the addition of one A. fumigatus spore yielded a standardised species-specific read number (SDSSRN) of 25.45 by mNGS; the detection rate would be 0.98 if SDSSRN was 2. Conclusion: mNGS facilitates the diagnosis of CA and may reduce the need for cerebral biopsy in patients with suspected CA. Trial Registration Number: Chinese Clinical Trial Registry, ChiCTR1800020442.

Approach to Neurologic Complications in the Immunocompromised Patient

Neurologic complications are common in immunocompromised patients, including those with advanced human immunodeficiency virus, transplant recipients, and patients on immunomodulatory medications. In addition to the standard differential diagnosis, specific pathogens and other conditions unique to the immunocompromised state should be considered in the evaluation of neurologic complaints in this patient population. A thorough understanding of these considerations is critical to the inpatient neurologist in contemporary practice, as increasing numbers of patients are exposed to immunomodulatory therapies. In this review, we provide a chief complaint-based approach to the clinical presentations and diagnosis of both infectious and noninfectious complications particular to immunocompromised patients.

Interaction Between the Complement System and Infectious Agents - A Potential Mechanistic Link to Neurodegeneration and Dementia

As part of the innate immune system, complement plays a critical role in the elimination of pathogens and mobilization of cellular immune responses. In the central nervous system (CNS), many complement proteins are locally produced and regulate nervous system development and physiological processes such as neural plasticity. However, aberrant complement activation has been implicated in neurodegeneration, including Alzheimer's disease. There is a growing list of pathogens that have been shown to interact with the complement system in the brain but the short- and long-term consequences of infection-induced complement activation for neuronal functioning are largely elusive. Available evidence suggests that the infection-induced complement activation could be protective or harmful, depending on the context. Here we summarize how various infectious agents, including bacteria (e.g., Streptococcus spp.), viruses (e.g., HIV and measles virus), fungi (e.g., Candida spp.), parasites (e.g., Toxoplasma gondii and Plasmodium spp.), and prion proteins activate and manipulate the complement system in the CNS. We also discuss the potential mechanisms by which the interaction between the infectious agents and the complement system can play a role in neurodegeneration and dementia.

Clinical manifestations, diagnosis, and treatment outcome of CNS aspergillosis: A systematic review of 235 cases

Aspergillus is a ubiquitous ascomycete that can cause a variety of clinical presentations depending on immune status. Central nervous system aspergillosis is a fatal disease with non-specific clinical features. The aim of this systematic review was to evaluate the epidemiology, clinical features, diagnosis and therapeutic interventions in CNS aspergillosis patients. We also aimed to examine the possible predictors of mortality in neuroaspergillosis. Literature search was performed in Medline, PubMed, and Google scholar and all patients≥18 years with proven CNS aspergillosis were included. A total of 175 articles (235 patients) were included in the final analysis. Their mean age was 51 years and the majority were male (57.4%). Overall case-fatality was 45.1%. Aspergillus fumigatus was the most common species (70.8%) followed by A. flavus (18.6%). Corticosteroids (22.6%), malignancy (19.1%) and diabetes mellitus (14%) were the most common risk factors. Neuroimaging findings included cerebral abscess (70.2%), meningitis (14%), infarction (13.2%) and mycotic aneurysm (8.9%). Disseminated disease (29.2% vs 17.8%, p 0.03), CSF hypoglycorrhachia (48.1% vs 22.2%, P: 0.001) and heightened CSF galactomannan (3.62 vs 2.0ng/ml, p 0.05), were the factors associated with poor outcome in neuroaspergillosis. Persons infected with Aspergillus flavus (13.1% vs 3.1%, P: 0.01), and having been treated with Voriconazole (51.9% vs 29.2%, P: 0.004) were more likely to survive. Our review will provide insight into the different spectrums of CNS aspergillosis. Notwithstanding the promising role of Voriconazole, future work is required to ascertain the role of combination antifungal therapy.

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.

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.

Diagnosis of Vitreoretinal Aspergillosis with Transvitreal Retinochoroidal Biopsy

Diagnosing culture-proven endophthalmitis is complicated by the insufficient yield of intraocular samples and the variety of etiologies which mimic true endophthalmitis. In cases of impending vision loss where vitreous biopsy cannot provide a definitive diagnosis, transvitreal retinochoroidal biopsy can be an effective next step. Our case is a 48-year-old male with B-cell acute lymphoblastic leukemia that presented with counting fingers vision, redness, and tearing of the left eye. Exam showed cell and flare with hypopyon as well as dense vitritis. The patient underwent diagnostic pars plana vitrectomy and vitreous culture was negative at the time. Flow cytometry demonstrated no malignant cells. However, the patient's vision and mental status continued to clinically decline despite being started on intravitreal and systemic antibiotic and antifungal therapy. Neuroimaging revealed rim-enhancing brain lesions. Transvitreal retinochoroidal biopsy was performed in an elevated area of the retina. The biopsy helped rule out malignancy and showed acute-angle, septate, branching hyphae characteristic of Aspergillus fumigatus. Ultimately, the vitreous biopsy, cultures, and a biopsy from the left frontal lobe brain abscess all confirmed this diagnosis as well. Transvitreal retinochoroidal biopsy can play a role in the diagnosis of a case of posterior uveitis and can be particularly effective in diagnosing a fungal endophthalmitis.

[Aspergillus in airway material : Ignore or treat?]

Fungi of the genus Aspergillus are ubiquitously present. Even though humans inhale Aspergillus spores daily under natural conditions, Aspergillus-associated pulmonary diseases only occur under special circumstances. Whether an Aspergillus-associated disease develops and which type of Aspergillus-associated disease develops depends on the constitution of the host. The spectrum of Aspergillus-associated pulmonary diseases ranges from allergic diseases, such as hypersensitivity pneumonitis to allergic infectious diseases, such as allergic bronchopulmonary aspergillosis (ABPA) and bronchocentric granulomatosis (BG) to infectious diseases, such as invasive (IA) or semi-invasive aspergillosis (SIA) and chronic pulmonary aspergillosis (CPA). Identification of Aspergillus spp. from sputum or bronchopulmonary secretions is not sufficient for a definitive diagnosis of Aspergillus-associated infections. The gold standard is the identification of Aspergillus spp. from lung tissue by culture or by histopathological methods; however, in clinical practice the decision to initiate antifungal therapy is more often based on immunological methods, such as the detection of Aspergillus-specific IgG antibodies from peripheral blood or galactomannan antigens from bronchoalveolar lavages. Acute IA or SIA infections have a high mortality and require immediate antifungal therapy. With rare exceptions CPA cannot be cured by medicinal therapy alone; however, active CPA can be brought into remission with antifungal therapy. Eradication of Aspergillus in CPA can as a rule only be successful using a combined antimycotic and surgical intervention.

Fungal infections in pediatric neurosurgery

INTRODUCTION

Invasive mycosis of the central nervous system represent a diverse group of diseases that have gradually emerged as not only opportunistic infections in patients with immune susceptibility due to congenital and acquired deficiency, immunomodulation, solid organ and stem cell transplantation, hematological malignancies, and chronic steroid use but also in selected risk populations such as low weight preterm infants, patients with shunted hydrocephalus and external ventricular drainages, skull base surgery, and head injury.

OBJECTIVES

The purpose of this review is to familiarize the pediatric neurosurgeon with the most common mycosis and their clinical scenarios which can be encountered in the clinical practice, with special emphasis on clinical, radiological, and laboratory diagnosis beyond classical microorganism cultures as well as options in medical and surgical treatment given the high incidence of morbidity and mortality associated with these challenging entities.

METHODS

We conducted an online database review (Ovid, PubMed) gathering relevant English language literature published in the last 20 years with special emphasis on recent breakthroughs in the diagnosis and treatment of invasive mycosis of the CNS as well as reported cases within the pediatric neurosurgical literature and their surgical management.

RESULTS

Fungal agents capable of invading the CNS can behave as aggressive entities with rapid progression manifesting as overwhelming meningoencephalitis with vascular compromise or can lead to space-occupying lesions with abscess formation which require prompt diagnosis by either laboratory identification of the components of these biological agents and their host response or by obtaining tissue specimens for microbiological identification which may not be straightforward due to prolonged culture time.

CONCLUSION

Following a high degree of suspicion with prompt initiation of antifungal agents and reversal of potential immunosuppressant therapies along with neurosurgical evacuation of intracranial collections or removal of infected hardware (CSF shunts) can lead to more optimistic outcomes of these complex clinical scenarios.

Infections in the immunocompromised child

Prevention and management of opportunistic infections in children is particularly relevant in an era demonstrating an increased prevalence of immunocompromising conditions. The presence of an unusual organism which results in serious infection in a child should therefore always raise the consideration of immune compromise. The more common opportunistic infections have become easier to recognize in recent times due to improved awareness and more refined diagnostic testing. Targeted treatment is usually followed by long-term prophylactic medication. The impact of these conditions on patient outcome is of clear significance and certainly warrants further discussion.

Intracranial Aspergillosis in an Immunocompetent Young Woman

Intracranial aspergillosis (ICA) is very rare in the immunocompetent individuals, usually misdiagnosed as a tumor or an abscess. A high index of clinical suspicion is required in patients who present with focal neurological deficits, headache, or seizures. We report the case of a 25-year-old immunocompetent female, who presented with a 15-month history of headache, seizures, left-sided proptosis and ophthalmoplegia, and right hemiparesis. Recovery from the symptoms and decrease in the lesion size seen on the radiological assessment were achieved through two decompressive craniotomies followed by prolonged combined systemic antifungal therapies. Although the initial neuroimaging suggested a mitotic pathology, the surgical sample confirmed ICA. Now the patient is on single antifungal therapy (Tab. voriconazole, 200 mg twice daily) and doing her daily activities, but with a reduced intelligent quotient. We report a challenging case of ICA where multiple courses of combined antifungal therapies and repeat surgeries paved the way for a good prognosis.

Role of microglia in fungal infections of the central nervous system

Most fungi are capable of disseminating into the central nervous system (CNS) commonly being observed in immunocompromised hosts. Microglia play a critical role in responding to these infections regulating inflammatory processes proficient at controlling CNS colonization by these eukaryotic microorganisms. Nonetheless, it is this inflammatory state that paradoxically yields cerebral mycotic meningoencephalitis and abscess formation. As peripheral macrophages and fungi have been investigated aiding our understanding of peripheral disease, ascertaining the key interactions between fungi and microglia may uncover greater abilities to treat invasive fungal infections of the brain. Here, we present the current knowledge of microglial physiology. Due to the existing literature, we have described to greater extent the opportunistic mycotic interactions with these surveillance cells of the CNS, highlighting the need for greater efforts to study other cerebral fungal infections such as those caused by geographically restricted dimorphic and rare fungi.

True mycotic aneurysm in a patient with gonadotropinoma after trans-sphenoidal surgery

Background:

Immunosuppressive therapy, prolonged antibiotic use, and intrathecal injections are known risk factors for the development of invasive aspergillosis. Central nervous system (CNS) aspergillosis can manifest in many forms, including mycotic aneurysm formation. The majority of the mycotic aneurysms presents with subarachnoid hemorrhage after rupture and are associated with high mortality. Only 3 cases of true mycotic aneurysms have been reported following trans-sphenoidal surgery.

Case Description:

A 38-year-old man was admitted with nonfunctioning pituitary adenoma for which he underwent trans-sphenoidal surgery. Three weeks later, he presented with cerebrospinal fluid (CSF) rhinorrhea and meningitis. He was treated with intrathecal and intravenous antibiotics, stress dose of glucocorticoids, and lumbar drain. The defect in the sphenoid bone was closed endoscopically. After 3 weeks of therapy, he suddenly became unresponsive, and computed tomography of the head showed subarachnoid hemorrhage. He succumbed to illness on the next day, and a limited autopsy of the brain was performed. The autopsy revealed extensive subarachnoid hemorrhage and aneurysmal dilatation, thrombosis of the basilar artery (BA), multiple hemorrhagic infarcts in the midbrain, and pons. Histopathology of the BA revealed the loss of internal elastic lamina and septate hyphae with an acute angle branching on Grocott's methenamine silver stain, conforming to the morphology of Aspergillus.

Conclusion:

The possibility of intracranial fungal infection should be strongly considered in any patient receiving intrathecal antibiotics who fails to improve in 1–2 weeks, and frequent CSF culture for fungi should be performed to confirm the diagnosis. Since CSF culture has poor sensitivity in the diagnosis of fungal infections of CNS; empirical institution of antifungal therapy may be considered in this scenario.

[Cervical aspergillosis with dissemination to the central nervous system: Case reports and review of the literature]

BACKGROUND

Invasive aspergillosis (IA) of the central nervous system (CNS) is an uncommon condition that usually occurs in immunocompromised patients. This illness can manifest as meningitis, or as a micotic aneurism, stroke or abscess. The infection affects the CNS either primarily or, more often, secondarily via blood dissemination from a distant focus, and has a poor prognosis. We present a patient with IA primarily affecting the cervical bones, with later spread into the brain.

CASE DESCRIPTION

A 25-year old male was receiving chemotherapy for acute lymphocytic leukemia when he developed pneumonitis secondary to methotrexate and was started on corticosteroids. He subsequently developed cervicalgia, prompting a needle biopsy of the fourth vertebrae, after which a diagnosis of osteomyelitis was made. Even though the biopsy culture was negative, empirical antibiotics were initiated. A parietal lobe lesion was treated surgically months later after the patient presented with three episodes of transient aphasia. After A. fumigatus grew in culture, the patient's antibiotic regimen was changed to treat the specific agent with a good response.

CONCLUSION

IA must be considered a possibility whenever an immunocompromised patient presents with a new brain lesion. These lesions require surgical evacuation, a procedure that allows for diagnostic confirmation and enhances prognosis. Appropriate anti-fungal therapy must be started as soon as the diagnosis is confirmed. In addition, the patient's neurological exam must be repeated and images obtained periodically to monitor treatment and detect possible recurrences.

Efficacy and toxicity evaluation of new amphotericin B micelle systems for brain fungal infections

The aim of this work is to study the micelle systems of amphotericin B (AmB) and surfactant sodium deoxycholate (NaDC) as possible formulations to treat brain fungal infections. Fungizone(®) and Ambisome(®) were used as AmB references. The particle size, aggregation state, toxicity and efficacy of AmB:NaDC micelles were studied with increasing proportions of NaDC. Differences in the size and aggregation state of the reference formulations and micellar NaDC formulations might explain the differences in their distribution and therefore in their toxicity and efficacy. AmB:NaDC 1:0.8 and 1:1.5 nano-sized micelle systems showed a poly-aggregated form of AmB and small mean particle size (450-750 nm). The AmB:NaDC 1:0.8 and AmB:NaDC 1:1.5 micelle systems studied showed an 8-fold lower toxicity than Fungizone(®). Efficacy was examined in a murine candidiasis model by determining the survival rate and tissue burden reduction in kidneys and brain. The AmB:NaDC 1:1.5 micellar system at 5mg/kg of AmB and the highest amount of NaDC (7.5 mg/kg) presented a good survival rate, and induced a major clearance of brain infection. The new AmB:NaDC 1:1.5 nano-sized micelle system is a promising formulation with a good efficacy/toxicity ratio, which can be attributed to its particle size, AmB aggregation state and NaDC content.

Dramatic response to itraconazole in central nervous system aspergillosis complicating acute promyelocytic leukemia

Abstract Fungal infection is a rare complication of acute leukemia, in which a combination of voriconazole and amphotericin B is a first-line regimen of treatment. Here administration of itraconazole plus caspofungin resulted in a dramatic response in a patient with acute promyelocytic leukemia (APL).

Treatment of invasive fungal infections in cancer patients-updated recommendations of the Infectious Diseases Working Party (AGIHO) of the German Society of Hematology and Oncology (DGHO)

The Infectious Diseases Working Party (AGIHO) of the German Society of Hematology and Oncology (DGHO) here presents its updated recommendations for the treatment of documented fungal infections. Invasive fungal infections are a main cause of morbidity and mortality in cancer patients undergoing intensive chemotherapy regimens. In recent years, new antifungal agents have been licensed, and agents already approved have been studied in new indications. The choice of the most appropriate antifungal treatment depends on the fungal species suspected or identified, the patient's risk factors (e.g., length and depth of neutropenia), and the expected side effects. This guideline reviews the clinical studies that served as a basis for the following recommendations. All recommendations including the levels of evidence are summarized in tables to give the reader rapid access to the information.

Cerebral aspergillosis with multiple enhancing nodules in the right cerebral hemisphere in the immune-competent patient

Aspergillosis in the central nervous system (CNS) is a very rare disease in immune-competent patients. There was a case of a healthy man without a history of immune-compromised disease who had invasive aspergillosis with unusual radiologic findings. A 48-year-old healthy man with diabetes mellitus, presented with complaints of blurred vision that persisted for one month. Brain magnetic resonance imaging (MRI) showed multiple nodular enhancing lesions on the right cerebral hemisphere. The diffusion image appeared in a high-signal intensity in these areas. Cerebrospinal fluid examination did not show any infection signs. An open biopsy was done and intraoperative findings showed grayish inflammatory and necrotic tissue without a definitive mass lesion. The pathologic result was a brain abscess caused by fungal infection, morphologically aspergillus. Antifungal agents (Amphotericin B, Ambisome and Voriconazole) were used for treatment for 3 months. The visual symptoms improved. There was no recurrence or abscess pocket, but the remaining focal enhanced lesions were visible in the right temporal and occipital area at a one year follow-up MRI. This immune-competent patient showed multiple enhancing CNS aspergillosis in the cerebral hemisphere, which had a good outcome with antifungal agents.

47 year-old man with HIV infection and hemiplegia

CNS aspergillosis is often missed in the setting of advanced HIV infection, especially in the absence of presumed risk factors such as neutropenia or prior steroid treatment. We describe the postmortem evaluation of the brain of a patient with AIDS that developed progressive neurologic deterioration. Sequence brain MRIs, CSF analysis, and multiple presumed treatments failed to reveal the possible causes or improve his ongoing condition. His brain autopsy showed numerous abscesses with septated hyphae consistent with CNS angioinvasive aspergillosis.

Invasive fungal infection of the central nervous system in a patient with acute myeloid leukaemia

Background:

Although the new intensive chemotherapeutic programs introduced recently into hematooncological therapies have led to a higher number of recoveries, persistent neutropenia favours the spread of severe infections, frequently fungal infections. Systemic fungal infections in patients treated for proliferative diseases of the hematopoietic system are characterised by a severe, progressing course and high morbidity.

Case Reports:

We present a case report that demonstrates the diagnostic problem of lesions in the central nervous system which developed following the fourth block of chemotherapy in an eight-year-old boy treated for acute myeloid leukaemia. The risk factors, high values of the inflammatory parameters and imaging results enabled us to diagnose a fungal infection of the central nervous system.

Results:

A fast improvement in the clinical condition of the patient after the applied antifungal therapy and the regression of lesions in the central nervous system shown in the imaging studies confirmed our final diagnosis.

Complement Attack against Aspergillus and Corresponding Evasion Mechanisms

Invasive aspergillosis shows a high mortality rate particularly in immunocompromised patients. Perpetually increasing numbers of affected patients highlight the importance of a clearer understanding of interactions between innate immunity and fungi. Innate immunity is considered to be the most significant host defence against invasive fungal infections. Complement represents a crucial part of this first line defence and comprises direct effects against invading pathogens as well as bridging functions to other parts of the immune network. However, despite the potency of complement to attack foreign pathogens, the prevalence of invasive fungal infections is increasing. Two possible reasons may explain that phenomenon: First, complement activation might be insufficient for an effective antifungal defence in risk patients (due to, e.g., low complement levels, poor recognition of fungal surface, or missing interplay with other immune elements in immunocompromised patients). On the other hand, fungi may have developed evasion strategies to avoid recognition and/or eradication by complement. In this review, we summarize the most important interactions between Aspergillus and the complement system. We describe the various ways of complement activation by Aspergillus and the antifungal effects of the system, and also show proven and probable mechanisms of Aspergillus for complement evasion.

Invasive intracranial aspergillosis in an immunocompetent patient after dental extraction

Invasive intracranial aspergillosis in immunocompetent patients remains a rarity. We report such a case in a male who developed symptoms after a dental extraction. Attention should be paid to atypical central nervous system symptoms after dental procedures; early diagnosis and management are of great importance to improve outcomes.

[Infections of the central nervous system in the immuno-compromised]

Infections of the central nervous system (CNS) can be caused by a variety of pathogens, depending on whether the number and function of T-cells or monocytes are impaired (as in HIV patients) or whether the number and function of polymorphonuclear granulocytes are reduced or impaired, as typically seen in patients on immunosuppressive therapy, post transplantation, etc.. The first part of the chapter deals with CNS infections associated with reduced or abnormal T-cell (or monocytic) function and number, mainly seen in HIV patients, such as cerebral toxoplasmosis, CNS cryptococcosis, cytomegalovirus encephalitis, and progressive multifocal leukoencephalopathy. The clinical presentation, diagnostic procedures, as well as therapeutic and prophylactic management of these diseases are described in detail. The second part of the chapter deals with diseases usually seen in patients with impaired or reduced number and function of polymorphonuclear granulocytes. Such CNS infections are frequently caused by viral, bacterial, or fungal pathogens and are described in their clinical presentation, their diagnostic procedures and the best possible therapeutic and prophylactic management.

Magnetic resonance methods and applications in pharmaceutical research

This review presents an overview of some recent magnetic resonance (MR) techniques for pharmaceutical research. MR is noninvasive, and does not expose subjects to ionizing radiation. Some methods that have been used in pharmaceutical research MR include magnetic resonance spectroscopy (MRS) and magnetic resonance imaging (MRI) methods, among them, diffusion-weighted MRI, perfusion-weighted MRI, functional MRI, molecular imaging and contrast-enhance MRI. Some applications of MR in pharmaceutical research include MR in metabonomics, in vivo MRS, studies in cerebral ischemia and infarction, degenerative joint diseases, oncology, cardiovascular disorders, respiratory diseases and skin diseases. Some of these techniques, such as cardiac and joint imaging, or brain fMRI are standard, and are providing relevant data routinely. Skin MR and hyperpolarized gas lung MRI are still experimental. In conclusion, considering the importance of finding and characterizing biomarkers for improved drug evaluation, it can be expected that the use of MR techniques in pharmaceutical research is going to increase in the near future.

Recommendations for the treatment of established fungal infections

Evidence-based guidelines for the treatment of established fungal infections in the adult haematology/oncology setting were developed by a national consensus working group representing clinicians, pharmacists and microbiologists. These updated guidelines replace the previous guidelines published in the Internal Medicine Journal by Slavin et al. in 2004. The guidelines are pathogen-specific and cover the treatment of the most common fungal infections including candidiasis, aspergillosis, cryptococcosis, zygomycosis, fusariosis, scedosporiosis, and dermatophytosis. Recommendations are provided for management of refractory disease or salvage therapies, and special sites of infections such as the cerebral nervous system and the eye. Because of the widespread use newer broad-spectrum triazoles in prophylaxis and empiric therapy, these guidelines should be implemented in concert with the updated prophylaxis and empiric therapy guidelines published by this group.

Complement induction and complement evasion in patients with cerebral aspergillosis

Cerebral aspergillosis is a mostly lethal infection of the central nervous system. Former results identified low cerebral complement levels as one cause for insufficient immune reaction. Therefore we studied cerebral complement expression after fungal invasion and investigated putative mechanisms of Aspergillus spp to cope with the complement-induced selection pressure. Brain tissue derived from patients with cerebral aspergillosis or non-infected individuals was analyzed immunohistochemically for complement synthesis. Correlations between expression levels were determined statistically. Increased complement synthesis, a prerequisite for strengthened antifungal potency, was visible in resident astrocytes, neurons, oligodendrocytes as well as in infiltrating macrophages after fungal infection. Surprisingly, microglia, although regarded as major immune cells, only marginally participated in synthesis of most complement proteins. Several evasion mechanisms were found that help the fungus to establish a cerebral infection even in the presence of complement: Fungal hyphae limit the surface deposition of C3 and thus interfere with complement-dependent phagocytosis. Furthermore, the "sealing off" in brain abscesses not only inhibits fungal spreading but also forms protection shields against complement attack. Complement indeed seems to represent an important selection pressure and evokes the development of fungal evasion mechanisms. Counteractions for these evasion processes might represent interesting therapeutic approaches.