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.

Aspergillus galactomannan antigen for diagnosis and treatment monitoring in cerebral aspergillosis.

Invasive aspergillosis, especially neuroaspergillosis, predominantly affects immunocompromised patients such as transplant recipients. Early diagnosis and subsequent early initiation of therapy may improve final outcome. In cerebral aspergillosis, samples for culture or histopathology, the diagnostic reference standard, are often impossible to obtain without risk. Because of these limitations, serological, nucleic acid amplification tests such as polymerase chain reaction or enzyme immunoassay from cerebrospinal fluid appear advantageous for early diagnosis and probably also for therapy monitoring. We report on the successful detection and treatment monitoring by serial testing of galactomannan in cerebrospinal fluid in a patient with neuroaspergillosis after heart transplant.

Central nervous system aspergillosis in immunocompetent patients: Case series and literature review.

The aim of this study was to investigate the clinical characteristics of central nervous system (CNS) aspergillosis in immunocompetent patients.This study enrolled six immunocompetent patients diagnosed with CNS aspergillosis. Additionally, we reviewed the clinical profiles for 28 cases reported in the literature. The age, gender, etiology of Aspergillus infection, clinical manifestations, location of the lesion, treatment, and prognosis were analyzed.There were 19 men (average age, 54.6 ±â€Š14.3 years) and 15 women (average age, 47.0 ±â€Š19.4 years). The clinical manifestations included headache (55.9%; n = 19), visual impairment (32.4%; n = 11), diplopia (32.4%; n = 11), hemiplegia (20.6%; n = 7), fever (17.6%; n = 6), and epilepsy (8.8%; n = 3). According to the radiological features, CNS aspergillosis lesions were divided into two subtypes: parenchymal lesions in the cerebral lobes (n = 11), and meningeal lesions in the meninges (n = 23). The patients with meningeal lesions are easy to be complicated with more serious cerebrovascular diseases, such as subarachnoid hemorrhage and massive infarction. Most of the lesions in brain parenchyma were abscess formation, and magnetic resonance imaging showed ring enhancement. The clinical diagnosis of Aspergillus infection was mainly based on brain biopsy (n = 14), autopsy (n = 8), pathological examination of adjacent brain tissues (n = 7), cerebrospinal fluid (CSF) or tissue culture (n = 3), and second-generation sequencing analysis of the CSF (n = 3). Clinical improvement was achieved in 23 cases, and 11 patients succumbed to the disease. Voriconazole treatment was effective in 24 (70.6%) cases.Immunocompetent subjects are also at risk for Aspergillus infections. Concomitant cerebrovascular diseases are common in patients with CNS aspergillosis, especially in patients with meningeal aspergillosis. Parenchymal aspergillosis lesions are usually localized and manifest as brain abscesses with annular enhancement on magnetic resonance imaging. Biopsy, CSF culture, and next-generation sequencing are mainstream diagnostic modalities. Voriconazole is an effective treatment for Aspergillus infection, and early diagnosis and treatment should be highlighted.

Chronic Meningitis Investigated via Metagenomic Next-Generation Sequencing.

Importance: Identifying infectious causes of subacute or chronic meningitis can be challenging. Enhanced, unbiased diagnostic approaches are needed. Objective: To present a case series of patients with diagnostically challenging subacute or chronic meningitis using metagenomic next-generation sequencing (mNGS) of cerebrospinal fluid (CSF) supported by a statistical framework generated from mNGS of control samples from the environment and from patients who were noninfectious. Design, Setting, and Participants: In this case series, mNGS data obtained from the CSF of 94 patients with noninfectious neuroinflammatory disorders and from 24 water and reagent control samples were used to develop and implement a weighted scoring metric based on z scores at the species and genus levels for both nucleotide and protein alignments to prioritize and rank the mNGS results. Total RNA was extracted for mNGS from the CSF of 7 participants with subacute or chronic meningitis who were recruited between September 2013 and March 2017 as part of a multicenter study of mNGS pathogen discovery among patients with suspected neuroinflammatory conditions. The neurologic infections identified by mNGS in these 7 participants represented a diverse array of pathogens. The patients were referred from the University of California, San Francisco Medical Center (n = 2), Zuckerberg San Francisco General Hospital and Trauma Center (n = 2), Cleveland Clinic (n = 1), University of Washington (n = 1), and Kaiser Permanente (n = 1). A weighted z score was used to filter out environmental contaminants and facilitate efficient data triage and analysis. Main Outcomes and Measures: Pathogens identified by mNGS and the ability of a statistical model to prioritize, rank, and simplify mNGS results. Results: The 7 participants ranged in age from 10 to 55 years, and 3 (43%) were female. A parasitic worm (Taenia solium, in 2 participants), a virus (HIV-1), and 4 fungi (Cryptococcus neoformans, Aspergillus oryzae, Histoplasma capsulatum, and Candida dubliniensis) were identified among the 7 participants by using mNGS. Evaluating mNGS data with a weighted z score-based scoring algorithm reduced the reported microbial taxa by a mean of 87% (range, 41%-99%) when taxa with a combined score of 0 or less were removed, effectively separating bona fide pathogen sequences from spurious environmental sequences so that, in each case, the causative pathogen was found within the top 2 scoring microbes identified using the algorithm. Conclusions and Relevance: Diverse microbial pathogens were identified by mNGS in the CSF of patients with diagnostically challenging subacute or chronic meningitis, including a case of subarachnoid neurocysticercosis that defied diagnosis for 1 year, the first reported case of CNS vasculitis caused by Aspergillus oryzae, and the fourth reported case of C dubliniensis meningitis. Prioritizing metagenomic data with a scoring algorithm greatly clarified data interpretation and highlighted the problem of attributing biological significance to organisms present in control samples used for metagenomic sequencing studies.

Two rare cases of central nervous system opportunistic mycoses.

This article presents two cases of opportunistic mycoses (OMs) of the central nervous system (CNS) caused by Cryptococcus neoformans and Aspergillus nidulans, respectively. The patients were hospitalised in local hospitals between 2009 and 2011 because of unspecific symptoms (fever, headache, and/or weight lost). Duration of symptoms varied from 4 days to over 2 weeks. The patients were treated with antibiotics and symptomatically. OM was not suspected in any of them. The patients became critically ill with symptoms of CNS involvement and were transferred to the Intensive Care Unit (ICU) of the University Hospital for Infectious diseases (UHID) in Zagreb. None of the patients belonged to the high-risk population for developing OMs. They were not HIV-infected, had no transplantation of bone marrow or solid organ, and were not on severe immunosuppressive chemotherapy. Fungi were isolated from cerebrospinal fluid (CSF) samples and, in one patient, from aspirate of cerebral abscess. Isolation and mycological identification of all fungal isolates and in vitro antifungal susceptibility testing of these isolates were done at the Reference Centre for Mycological Diagnostics of Systemic and Disseminated Infections (RCMDSDI) in Zagreb. The patient with cryptococcal meningitis was treated with amphotericin B and fluconazole and the patient with cerebral aspergilloma with voriconazole.