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

Challenging Treatment of Disseminated Aspergillosis in a Child With Nephrotic Syndrome

INTRODUCTION

Central nervous system (CNS) aspergillosis is an opportunistic infection with an increasing incidence and a high mortality rate. It is seen in immunocompromised patients as well as in immunocompetent patients. Here, we present disseminated aspergillosis in a child with nephrotic syndrome treated with long-term and aggressive systemic antifungal treatment and intraventricular (IVent) liposomal amphotericin B (L-AmB) as well as surgical excision and drainage due to difficulty in management.

CASE REPORT

A 10-year-old boy with nephrotic syndrome on steroid therapy was admitted with limping and weakness. The cranial magnetic resonance imaging showed multiple intraparenchymal scattered abscesses. The largest one was excised and drained. Abscess culture revealed Aspergillus fumigatus and histopathological examination revealed septate hyphae compatible with Aspergillosis. Intravenous (IV) voriconazole was started, and IV L-AmB was added. The size of lesions and perilesional edema continued to increase, and then IVent L-AmB was added. With IVent and systemic antifungal treatment, regression of the lesions was observed. He was followed up with oral voriconazole and weekly IVent L-AmB. After 2 and a half months, he was re-operated because of increased lesion size, number and perilesional edema, and IV voriconazole and other salvage antifungal therapies were started. Since the lesions had decreased and remained stable, IV voriconazole was switched to oral therapy, and he was followed up as an outpatient. Immunodeficiency diseases were excluded by immunological and genetic tests.

CONCLUSION

Management of central nervous system aspergillosis can be challenging despite long-term and aggressive systemic and IVent antifungal treatment as well as surgical excision and drainage.

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.

Invasive pulmonary and central nervous system aspergillosis in a child: A case report and literature review

RATIONALE

Children with haematological malignancies have a higher risk of developing aggressive pulmonary aspergillosis and a higher mortality rate. The most common site of extrapulmonary aspergillosis in children is the central nervous system (CNS), and the death rate is higher when CNS is affected. Therefore, early diagnosis and treatment of invasive aspergillosis are essential for reducing mortality.

PATIENT CONCERNS

We report a case of an 8-year-old girl with acute lymphoblastic leukaemia who developed invasive pulmonary aspergillosis complicated by CNS aspergillosis. Aspergillus was confirmed by metagenomic sequencing of pathogenic microorganisms.

DIAGNOSES

Invasive pulmonary and central nervous system aspergillosis.

INTERVENTIONS

The patient was treated with combined systemic antifungal agents (voriconazole and liposomal amphotericin B) and intrathecal injection of amphotericin B.

OUTCOMES

The treatment was well tolerated and resulted in remarkable clinical and radiological head improvements.

LESSONS

Invasive aspergillosis has a high mortality rate and requires early diagnosis and treatment. Pathogenic microbial metagenomic sequencing is a convenient method to assist in the early diagnosis of aspergillosis. Voriconazole is the drug of choice for the treatment of invasive aspergillosis. When CNS aspergillosis occurs, it can be combined with other systemic antifungal drugs and intrathecal injection of amphotericin B.

Infection due to Aspergillus flavus and Rhizopus oryzae complex in a patient with diabetes mellitus

Fungal sinusitis is a pathology that can occur in patients with diabetes mellitus and be associated with a hyperglycemic crisis. It is an aggressive entity with local complications that include involvement of the orbit or the central nervous system, and vascular involvement. Despite surgical and antifungal treatment, mortality raises up to 75%. We report the case of a female patient with a diagnosis of diabetic ketoacidosis and signs of unilateral ophthalmoplegia, which led to the study with magnetic resonance imaging of the central nervous system, finding signs of sinusitis, meningitis, and cerebritis. Initial microbiological studies were negative, and biomarkers such as serum galactomannan and Cryptococcus antigen were also negative. After surgical management and the identification of Aspergillus flavus and Rhizopus spp. in sinus tissue, the patient received treatment with posaconazole and after two months of follow-up she presented clinical improvement. Dual fungal infection and infection by A. flavus are uncommon and clinically relevant entities, with no cases previously reported in our country, therefore this corresponds to a case of clinical interest.

Invasive Cerebral Aspergillosis in Non-Neutropenic Patients: A Case Series from Western India

PURPOSE

Invasive cerebral aspergillosis (ICA) is a rare but fatal infection affecting neutropenic immunocompromised patients. Recently cases have been reported in non-neutropenic settings also. We hereby present a series of ICA cases in non-neutropenic patients diagnosed at our tertiary care centre in Western India between March to October 2021.

METHODS

All patients with clinico-radiological suspicion of CNS infections were analysed. Data regarding Clinico-radiological features, diagnosis, treatment and outcome were collected. After ruling out bacterial, viral and mycobacterial causes, appropriate samples were sent for KOH (potassium hydroxide) wet mount, fungal culture, histopathology and serum/CSF galactomannan.

RESULTS

A total of four patients were diagnosed with ICA with a mean age of 43.5 years. Three patients had significant comorbidities; Diabetes mellitus, chronic liver disease and COVID-19 pneumonia treated with dexamethasone, respectively. One patient had no known predisposing factor. Radiologically, one patient presented with a frontal brain abscess and two patients had multiple subcortical hyperintensities. Three patients were diagnosed based on CSF galactomannan (Platelia™ Aspergillus antigen, Bio-Rad, France) with OD >1 and one patient had high serum galactomannan (OD >2). CSF culture grew Aspergillus species in two patients. All patients were treated with Voriconazole. One patient recovered, and the remaining three succumbed due to delayed presentation and extensive cerebral involvement.

CONCLUSION

Even in non-neutropenic patients, a high index of suspicion is warranted for cerebral aspergillosis. CSF galactomannan can be considered a reliable marker for diagnosing ICA in non-neutropenic settings. Early diagnosis allows timely antifungal therapy, which could be a key to improving the outcomes.

Rare case of aspergillus brain abscess in an immunocompromised patient

We present a case of aspergillus brain abscess in a 48‐year‐old woman with a history of kidney transplantation and no underlying central nervous system (CNS) disease. Follow‐up of the patient for 4 years shows normal findings. Early diagnosis and aggressive treatment could improve the prognosis of this fatal complication.

Serologic biomarkers in Candida and Aspergillus infections of the central nervous system: a comparison of galactomannan, mannan, and β-1,3-D-gucan testing from serum and cerebrospinal fluid

BACKGROUND

The incidence of Aspergillus and Candida CNS infection, which are characterized by high mortality rates, is underestimated. This underdiagnosis presumably results from the limitations of available diagnostic tools and the need for invasive sampling. Little is known about the role of serologic biomarkers in the setting of CNS aspergillosis and candidiasis.

PATIENTS, MATERIALS, METHODS

Serum (19) and cerebrospinal fluid (CSF; 10) samples of 19 patients, whose CNS specimens yielded growth of Aspergillus or Candida, were analyzed for different biomarkers for fungal infection, i.e., galactomannan (GM), galactomannoprotein (GP), mannan, anti-mannan-antibodies, and β-1,3-D-glucan (BDG). Serum and CSF specimens of time-matched patients (two each for every case of fungal CNS infection) were included as controls.

RESULTS

GM, GP, and BDG seropositivity was found in one, two, and three of five cases of CNS aspergillosis. BDG and mannan / anti-mannan-antibody sensitivity in proven CNS candidiasis was 40 % and 20 %, respectively. Applying the serum cut off, sensitivity in CSF testing was 100 % for GM and BDG, and 50 % for mannans. While serum specificity for all assays ranged from 89 - 97 %, specificity for CSF BDG was only 70 %. No false positive GM results from CSF were obtained.

CONCLUSION

Sensitivity for diagnosing CNS aspergillosis and CNS candidiasis from serum is mediocre for all serological biomarkers. GM testing in CSF proved excellent performance. With a sensitivity of 100 % but a specificity of only 70 %, CSF BDG might be most useful when used in patients with a high pre-test probability.

A case of influenza-associated invasive aspergillosis with cerebral hemorrhage due to infectious vasculopathy

An invasive aspergillosis (IA) primarily occurs among immunocompromised patients. Recently with an influenzae infection prevalently spreading, influenzae-associated invasive aspergillosis (IAIA) has been reported occasionally. By contrast, neuroleptic malignant syndrome (NMS) occurs rarely in psychiatric patients who are treated with Olanzapine. We report a 43 years old male with psychiatric disorder who had developed IAIA followed by NMS and cerebral hemorrhage as the result of aspergillus invasion to cerebral vessels. He had also super-infection of COVID-19, 13 months later to be saved completely after invasive mechanical respiratory supports. From clinical aspects, we would emphasize that it is of importance to find earlier co-occurrence of IAIA patients with cerebral hemorrhage due to secondary infectious vasculopathy of IA.

Development and validation of a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for the quantification of voriconazole in human cerebrospinal fluid

Background: A liquid chromatography-tandem mass spectrometry (LC-MS/MS). Method: For the quantification of voriconazole in human cerebrospinal fluid (CSF) was developed and validated, to guide the clinical use of voriconazole in the treatment of central nervous system infections. CSF samples were treated by protein precipitation with methanol containing fluconazole as the internal standard (IS). The supernatant was analyzed by LC-MS/MS using an Agilent EclipsePlus C18 column eluted with a methanol and water mobile phase at a flow rate of 0.4 mL min^-1. Quantification was performed by multiple-reaction monitoring using the precursor and product ion pair 350/280.9 for voriconazole and 307/219.9 for fluconazole. Results: The calibration curve was linear over the range of 0.1-10.0 μg mL^-1 (R² = 0.9991). The inter-day and intra-day precisions were <4.20% and <9.97%, respectively. The recoveries for the three concentrations (0.2, 1.0, and 8.0 μg mL^-1) were 99.96%, 107.00%, and 99.85%, and the matrix effects were 99.35%, 103.41%, and 99.64%, respectively. The stability under various conditions was also acceptable. The study also demonstrated that the CSF matrix could be replaced by plasma and artificial CSF. Conclusion: A simple and accurate method for the determination of voriconazole concentrations in human CSF was developed and validated, which can be used for drug monitoring in the treatment of central nervous system infections.

Rapid Genomic Diagnosis of Fungal Infections in the Age of Next-Generation Sequencing

Next-generation sequencing (NGS) technologies have recently developed beyond the research realm and started to mature into clinical applications. Here, we review the current use of NGS for laboratory diagnosis of fungal infections. Since the first reported case in 2014, >300 cases of fungal infections diagnosed by NGS were described. Pneumocystis jirovecii is the predominant fungus reported, constituting ~25% of the fungi detected. In ~12.5% of the cases, more than one fungus was detected by NGS. For P. jirovecii infections diagnosed by NGS, all 91 patients suffered from pneumonia and only 1 was HIV-positive. This is very different from the general epidemiology of P. jirovecii infections, of which HIV infection is the most important risk factor. The epidemiology of Talaromyces marneffei infection diagnosed by NGS is also different from its general epidemiology, in that only 3/11 patients were HIV-positive. The major advantage of using NGS for laboratory diagnosis is that it can pick up all pathogens, particularly when initial microbiological investigations are unfruitful. When the cost of NGS is further reduced, expertise more widely available and other obstacles overcome, NGS would be a useful tool for laboratory diagnosis of fungal infections, particularly for difficult-to-grow fungi and cases with low fungal loads.

Marine Bioactive Compounds against Aspergillus fumigatus: Challenges and Future Prospects

With the mortality rate of invasive aspergillosis caused by Aspergillus fumigatus reaching almost 100% among some groups of patients, and with the rapidly increasing resistance of A. fumigatus to available antifungal drugs, new antifungal agents have never been more desirable than now. Numerous bioactive compounds were isolated and characterized from marine resources. However, only a few exhibited a potent activity against A. fumigatus when compared to the multitude that did against some other pathogens. Here, we review the marine bioactive compounds that display a bioactivity against A. fumigatus. The challenges hampering the discovery of antifungal agents from this rich habitat are also critically analyzed. Further, we propose strategies that could speed up an efficient discovery and broaden the dimensions of screening in order to obtain promising in vivo antifungal agents with new modes of action.