Special scenarios in the management of central nervous system aspergillosis: a case series and review of literature

A case of intracranial infection caused by Aspergillus flavus originating from chronic otitis media

Central nervous system (CNS) aspergillosis is uncommon in immunocompetent patients. We present a 64-year-old man with chronic otitis media and uncontrolled diabetes. Aspergillus flavus was identified in cerebrospinal fluid via metagenomics next-generation sequencing technology. Initial voriconazole treatment offered limited relief, but personalized dosage adjustments, guided by drug concentration, led to remission. This case underscores the importance of diverse diagnostic approaches and tailored therapy for CNS Aspergillus infections.

Antifungal Drugs TDM: Trends and Update

PURPOSE

The increasing burden of invasive fungal infections results in growing challenges to antifungal (AF) therapeutic drug monitoring (TDM). This review aims to provide an overview of recent advances in AF TDM.

METHODS

We conducted a PubMed search for articles during 2016-2020 using "TDM" or "pharmacokinetics" or "drug-drug-interaction" with "antifungal," consolidated for each AF. Selection was limited to English language articles with human data on drug exposure.

RESULTS

More than 1000 articles matched the search terms. We selected 566 publications. The latest findings tend to confirm previous observations in real-life clinical settings. The pharmacokinetic variability related to special populations is not specific but must be considered. AF benefit-to-risk ratio, drug-drug interaction (DDI) profiles, and minimal inhibitory concentrations for pathogens must be known to manage at-risk situations and patients. Itraconazole has replaced ketoconazole in healthy volunteers DDI studies. Physiologically based pharmacokinetic modeling is widely used to assess metabolic azole DDI. AF prophylactic use was studied more for Aspergillus spp. and Mucorales in oncohematology and solid organ transplantation than for Candida (already studied). Emergence of central nervous system infection and severe infections in immunocompetent individuals both merit special attention. TDM is more challenging for azoles than amphotericin B and echinocandins. Fewer TDM requirements exist for fluconazole and isavuconazole (ISZ); however, ISZ is frequently used in clinical situations in which TDM is recommended. Voriconazole remains the most challenging of the AF, with toxicity limiting high-dose treatments. Moreover, alternative treatments (posaconazole tablets, ISZ) are now available.

CONCLUSIONS

TDM seems to be crucial for curative and/or long-term maintenance treatment in highly variable patients. TDM poses fewer cost issues than the drugs themselves or subsequent treatment issues. The integration of clinical pharmacology into multidisciplinary management is now increasingly seen as a part of patient care.

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.

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 ± 14.3 years) and 15 women (average age, 47.0 ± 19.4 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.

Fatal Case of Cerebral Aspergillum in an Immunocompetent Patient

Introduction: Cerebral aspergillum is rare and usually misdiagnosed because its presentation mimics tuberculous meningitis, brain abscess, or tumor. The diagnosis and treatment of central nervous system (CNS) infections due to Aspergillus are very difficult because accurate diagnosis is often made intra-operatively. Case Presentation: Here, we report a case of cerebral aspergilloma in an immunocompetent host. A 35-year-old man admitted with progressive left hemifacial paresthesia followed by severe pain in trigeminal nerve territory. On physical examination, except for fifth nerve palsy and difficult mastication, there was not any sensory and motor deficit. Magnetic resonance imaging (MRI) of the brain showed T1 iso and T2 low signal lesion in the left parasellar region with enhancement. The lesion is extended to the left side of the prepontine cistern in the course of trigeminal nerve, craniotomy, and total surgical resection of the mass was performed. Isolated brain lesion and the pathology from stereotactic biopsy confirmed cerebral aspergillosis. The result of testing for human immunodeficiency virus (HIV) was negative. Although the patient had two subsequent recurrences, at first, good outcome was achieved by treatment with a combination of surgical intervention, and antifungal amphotericin B deoxycholate was administered, then changed to voriconazole. Unfortunately, after two years, he experienced new progressive symptoms, and the patient died despite several reoperations due to malfunctioning of external ventricle devices as well as the treatment of recurrent post-operation meningitis and voriconazole therapy. Conclusions: Most cases of intracranial aspergillosis show that this infection is pathogenic in immunocompromised hosts; however, in some cases, invasive Aspergillus was reported as an opportunistic infection in immunocompetent patients. In these patients, though primary cranial aspergillosis is very rare, it is possible that isolated brain involvement in a previously healthy case may be explained by unknown defects in immune pathways or massive exposure to spores.