Cryptococcosis Research Articles

Tuberculous meningitis and cryptococcal meningitis co-infection in hospitalised patients in Durban, Kwa Zulu Natal (KZN), South Africa

Tuberculous meningitis and cryptococcal meningitis co-infection in hospitalised patients in Durban, Kwa Zulu Natal (KZN), South Africa

3D Printable Alginate-Chitosan Hydrogel Loaded With Ketoconazole Exhibits Anticryptococcal Activity.

Natural polymers have recently been investigated for various applications, such as 3D printing and healthcare, including treating infections. Among microbial infections, fungal diseases remain overlooked, with limited therapeutic options and high recurrence. Cutaneous cryptococcosis is an opportunistic fungal infection triggered by mechanical inoculation or hematogenous dissemination of the yeast that causes cryptococcal pneumonia and meningitis. Every year, Cryptococcus neoformans endanger the lives of immunosuppressed hosts, resulting in 180,000 deaths per year. Nonetheless, healthy individuals can also be affected by this fungal infection. Cryptococcosis has a restricted and expensive therapeutic regimen with no topical approach to skin manifestations. This study sought to create a 3D printable biodegradable polymeric hydrogel carrying ketoconazole, a low-cost antifungal drug with reported anticryptococcal activity. The developed hydrogel exhibited good 3D printability and rheological properties, including a pseudoplastic behavior. The FTIR spectra of cross-linked hydrogels revealed interactions between alginate and Ca+2, referred to as the egg-box model, indicated by the decrease in peaks at 1600 and 1410 cm-1. Furthermore, the hydrogel loaded with ketoconazole showed remarkable antifungal activity against C. neoformans strains indicated by inhibition zones, which cross-linking did not seem to affect its antifungal performance. The developed material remained structurally stable for up to 12 days (288 h) in swelling studies, and preliminary cytotoxicity performed with V79 cells indicates potential for invivo studies and topical application.

Unusual late presentation of cryptococcal meningitis with simultaneous CMV antigenemia in a kidney transplant recipient.

Cryptococcosis is the third most common invasive fungal infection in solid-organ transplant (SOT) recipients after candidiasis and aspergillosis. These patients are at risk of disseminated cryptococcosis because of immuosuppressive therapy. The median time to disease onset after kidney transplantation is approximately 35months and it rarely occurs more than 10years after transplantation. Herein, we report a case of 64-year-old kidney transplant recipient suffering from coexisting disseminated cryptococcosis with brain and skin involvement, together with cytomegalovirus (CMV) antigenemia more than 20years after transplant. She presented with frontal headache and bilateral hand tremor, in addition to multiple nodular lesions over bilateral lower limbs. The diagnosis was made after lumbar puncture and skin biopsy. She was successfully treated with a course of anti-fungal and anti-CMV regimen without any relapse of central nervous system infection. Our case illustrates that disseminated cryptococcosis can occur very late after organ transplant. It is thus important to watch out for late-onset opportunistic infections and strike the balance between risks of infections and rejections in SOT patients.

Post-infectious Inflammatory Response Syndrome after Cryptococcal Meningitis in a Patient with Sarcoidosis

Post-infectious Inflammatory Response Syndrome after Cryptococcal Meningitis in a Patient with Sarcoidosis

Cryptococcal Meningitis in HIV: A Comparative Study Between Asymptomatic and Symptomatic Cases and Mortality Parameters

Cryptococcal Meningitis in HIV: A Comparative Study Between Asymptomatic and Symptomatic Cases and Mortality Parameters

Implications of Undiagnosed Subclinical Cryptococcal Meningitis in Clinically Asymptomatic Low-Titer Cryptococcal Antigenemia Among PLWH: More Questions to Answer.

Implications of Undiagnosed Subclinical Cryptococcal Meningitis in Clinically Asymptomatic Low-Titer Cryptococcal Antigenemia Among PLWH: More Questions to Answer.

Clinical importance of cerebrospinal fluid protein levels in HIV-associated cryptococcal meningitis: Insights from a prospective cohort study in Uganda.

Cerebrospinal fluid (CSF) protein levels exhibit high variability in HIV-associated cryptococcal meningitis; however, its clinical implications remain unclear. We analyzed data from 890 adults with HIV-associated cryptococcal meningitis randomized into two clinical trials in Uganda between 2015 and 2021. CSF protein was grouped into < 100mg/dl (72%, n =641) and ≥ 100mg/dl (28%, n =249). We described baseline clinical variables and 18-week mortality by CSF protein groups. Those with CSF protein ≥ 100mg/dl were more likely to present with Glasgow coma scale score<15 (P < .01), self-reported seizures at baseline (P = .02), higher CD4 T-cell count (P < .001), and higher CSF white blood cells (P < .001). Moreover, those with a baseline CSF protein ≥ 100mg/dl also had a lower baseline CSF fungal burden (P < .001) and a higher percentage of sterile CSF cultures at day 14 (P = .02). Individuals with CSF protein ≥ 100mg/dl demonstrated a more pronounced immune response consisting of upregulation of immune effector molecules, pro-inflammatory cytokines, T-helper cell type 1 and 17 cytokines, and immune-exhaustion marker (P < .05). 18-week mortality risk in individuals with a CSF protein < 100mg/dl was 34% higher (unadjusted Hazard Ratio 1.34; 95% Confidence Interval, 1.05-1.70; P = .02) than those with CSF protein ≥ 100mg/dl. In HIV-associated cryptococcal meningitis, individuals with baseline CSF protein ≥ 100mg/dl more frequently presented with neurological symptoms, higher CSF inflammatory cytokines, reduced fungal burden, and lower mortality risk. The findings underscore the prognostic significance of baseline CSF protein levels in predicting disease severity and mortality risk in cryptococcal meningitis.

The molecular mechanisms by which the NLRP3 inflammasome regulates blood-brain barrier permeability following cryptococcal meningitis

ObjectiveTo investigate the mechanism underlying the regulation of blood-brain barrier permeability changes during cryptococcal meningitis by NLRP3 and Vimentin. MethodsSprague-Dawley rats were treated with WT Cryptococcus neoformans (Cn) or CPS1-/- Cn. Neuronal apoptosis was assessed using TUNEL staining, and pathological changes were observed using electron microscopy and HE staining. The expressions of NLRP3, Vimentin, and NF-κB in the cerebral cortex and human brain microvascular endothelial cells (HBMECs) were examined through Western blot and qRT-PCR. siNLRP3 and siVimentin were separately transfected into HBMECs, the expressions of specific factors were assessed. NF-κB and Vimentin levels were detected through immunofluorescence, apoptosis was measured using flow cytometry, and changes in the optical density (OD) of HRP were determined using ELISA. ResultsThe expressions of NLRP3, Vimentin, and NF-κB were upregulated following intervention with WT Cn in vivo and in vitro. Electron microscopy revealed loose nuclear membranes in neurons and increased apoptosis in the cerebral cortex and hippocampus induced by WT Cn, accompanied by a reduction in the OD of HRP in vitro. siNLRP3 decreased the expressions of Vimentin, nuclear NF-κB, and β-Tubulin in HBMECs, while siVimentin downregulated total NLRP3 and nuclear NF-κB levels. Both siNLRP3 and siVimentin reduced cell apoptosis after WT Cn infection. HBMECs displayed a reduced monolayer permeability to HRP and improved cell structure arrangement. ConclusionVimentin and the NLRP3 inflammasome are both implicated in the pathological process of cryptococcal meningitis. An interaction between Vimentin and the NLRP3 inflammasome is evident, likely mediated through the NF-κB signaling pathway.

A Patient With Cryptococcal Meningitis Accompanied With Acute Intracranial Hypertension Treated by Ventricular Abdominal-wall Drainage.

Intracranial hypertension is considered a common and severe complication of cryptococcal meningitis (CM), contributing to early mortality and neurological sequelae. Timely and effective control of elevated intracranial pressure is crucial for the management of CM. Herein, the authors present a case of ventricular abdominal wall drainage for CM accompanied with acute intracranial hypertension. Notably, the patient has a history of taking immunosuppressants for thoracic and abdominal diffuse lymphangiomatosis. After continuous drainage of cerebrospinal fluid combined with standardized antifungal treatment, the patient recovered well.

Navigating the Dual Threat: Cryptococcal and Tubercular Co-infections in PLHIV

Co-infections of Cryptococcosis and tuberculosis (TB) represent a significant clinical challenge, particularly in people living with HIV, due to their compounded impact on an already compromised immune system. Cryptococcus neoformans and Mycobacterium tuberculosis exploit immune dysfunction, often resulting in severe, disseminated infections with overlapping clinical symptoms, which complicates diagnosis and delays appropriate treatment. A 55-year-old HIV-positive male, recently initiated on ART (TLD regimen) was admitted with fever, headache, vomiting, irritability, and altered behavior. Poor adherence to ART and a CD4 count of 210 cells/cumm raised concerns about a CNS opportunistic infection, possibly cryptococcal meningitis and immune reconstitution inflammatory syndrome (IRIS). Examination revealed fever, irritability, neck stiffness, and positive Kernig's signs. Cryptococcal antigen was positive, and imaging suggested both cryptococcal and tubercular meningitis. Bronchoalveolar lavage confirmed tuberculosis. The patient was treated with liposomal amphotericin B, fluconazole, and rifampicin-sparing antitubercular therapy. After showing clinical improvement, he was discharged with dual therapy and stabilized after 3 weeks of hospitalization. Our findings emphasize the importance of comprehensive clinical guidelines and multidisciplinary management to address the complexities of treating this co-infection. Our case review underscores the need for integrated

Safety of different amphotericin B formulations among AIDS patients with invasive fungal disease: a retrospective observational study

We conducted a retrospective, observational study among acquired immune deficiency syndrome (AIDS) patients with cryptococcal meningitis or talaromycosis to assess AmB formulations-related adverse events (AEs). Total 205 eligible patients were enrolled. Of them, 139 received AmB therapy, 51 received liposomal AmB (L-AmB) therapy, and 15 received AmB cholesteryl sulfate complex (ABCD) therapy. The incidences of total AEs between the AmB, L-AmB and ABCD group had no significant differences. The ABCD group had significantly higher incidences of hepatotoxicity and hematological toxicity than the AmB and L-AmB groups. The incidence of grade 3–4 hematological toxicity in the ABCD group was significantly higher than that in the AmB and L-AmB groups. Multinomial logistic regression models showed that compared with AmB, ABCD had a higher risk for the occurrence of grade 3–4 hematological toxicity (aOR = 43.924, 95%CI 6.296-306.418; p < 0.001). We demonstrated that ABCD was more prone to hepatotoxicity and hematological toxicity than AmB and L-AmB among AIDS patients, which is worth noting.

Clinical Characteristics and Risk Factors for Cryptococcal Meningitis in Diverse Patient Populations in New York City.

Cryptococcal meningitis (CM) is responsible for 15%-20% of human immunodeficiency virus (HIV)-associated mortalities. CM prevalence has also increased in other immunocompromised populations of transplant recipients, patients with cancer, and individuals on immunomodulatory medication. This retrospective review included 51 definitive patients with CM hospitalized at a tertiary academic medical center in New York City between 2010 and 2023. We assessed clinical features and outcomes of CM, with additional analysis of factors related to antiretroviral therapy (ART) adherence in HIV-infected cases and immunomodulatory medication history of HIV-negative cases. The cohort had a mean (standard deviation) age of 47.1 ± 15.1 years, and was predominantly male (37, 72.5%). Of 32 patients with HIV, 3 (9.4%) were newly diagnosed with HIV at the time of CM hospitalization, 5 (15.6%) had recurrent CM, and 2 (6.3%) had a CM relapse. The majority (30, 93.8%) of patients with HIV were ART nonadherent. Of 19 HIV-negative patients, 8 (42.1%) were solid-organ transplant recipients, 5 (26.3%) had autoimmune conditions of sarcoidosis or systemic lupus erythematosus, and 3 (15.8%) had chronic lymphocytic leukemia. Six (11.8%) patients died during hospitalization, 4 of whom had HIV. The burden of CM in people with HIV and immunocompromised patients continues even in settings with accessible standard antifungal treatment though interventions of increased ART adherence for those with HIV and antifungal prophylaxis may improve morbidity and mortality.

Cerebrospinal Fluid Lactate Levels as a Prognostic Indicator in Patients With Cryptococcal Meningitis Who Are HIV Negative: A Retrospective Cohort Study.

Cryptococcal meningitis (CM) is a severe central nervous system infection. In patients with HIV infections and coexisting CM, elevated baseline cerebrospinal fluid (CSF) lactate levels can predict increased mortality. However, the CSF lactate level's significance in patients with CM who are HIV negative remains unclear, necessitating further investigation to elucidate the potential distinctions and enhance patient management. This study investigated the significance of CSF lactate levels in patients with CM who were HIV negative. This retrospective study utilized data from the clinical databases of patients who underwent lumbar punctures at a medical center in Kaohsiung City, southern Taiwan. Demographic data, CSF lactate levels, routine CSF analyses, and hematologic and neurologic findings were evaluated. The optimal CSF lactate threshold value was determined by the Youden index. This retrospective study included 70 patients with CM, among whom 44 (63%) and 26 (37%) tested negative and positive for HIV, respectively. The group without HIV exhibited higher CSF lactate levels, with an optimal CSF lactate cutoff point of 7.935 mmol/L for predicting 90-day mortality, resulting in significant predictive accuracies (area under the curve, 0.755; sensitivity, 57.1%; specificity, 100%); this value was an independent mortality predictor in patients who were HIV negative. In patients with CM who were HIV negative, CSF lactate levels ≥7.935 mmol/L correlated with higher mortality rates but without statistical significance. All patients with CM who were HIV negative and had CSF lactate levels ≥7.935 mmol/L died within 3 months of admission. Patients with CM who were HIV negative had elevated CSF lactate levels that correlated with adverse outcomes, enabling early identification of high-risk individuals.

Laboratory diagnosis of cryptococcal meningitis in an HIV-infected patient

Laboratory diagnosis of cryptococcal meningitis in an HIV-infected patient

Reassessment of the role of combination antifungal therapy in the current era.

Given the high mortality and morbidity associated with invasive fungal diseases (IFDs), the use of combination antifungal therapies is often considered despite the dearth of data. This review aims to summarize the current state of literature of combination antifungal therapies, discussing the potential roles of newer antifungal combinations and key considerations for their clinical use. In infections other than cryptococcal meningitis or in the setting of empirical treatment for suspected azole-resistant Aspergillus infections, the utility of the combination antifungal approaches remains controversial given the paucity of well designed randomized controlled trials. Data on potential combined antifungal treatments have been primarily limited to in-vitro studies, animal models, case reports and/or observational studies. With availability of novel antifungal agents (e.g. ibrexafungerp, fosmanogepix), combination therapy to treat mould infections should be re-visited. A phase 2 clinical trial of ibrexafungerp combined with voriconazole to treat invasive pulmonary aspergillosis is on-going. There is a need to investigate the use of combination antifungal agents. This includes delineating the indication of these combined antifungal therapies and determining how to use them most appropriately in the clinical setting.

Genetic mutations in Cryptococcus neoformans pyrimidine salvage pathway enzymes contribute to reduced susceptibility against 5-fluorocytosine

Cryptococcal meningitis is a high-mortality infection. Adding 5-fluorocytosine (5-FC) to its treatment improves outcomes, but resistance to 5-FC presents a significant challenge. We conducted whole-genome sequencing on seven C. neoformans isolates with varying 5-FC susceptibility, along with proteomic and in silico analyses. Our findings indicate that mutations in genes of the pyrimidine salvage pathway are responsible for 5-FC resistance. Specifically, we identified an E64G missense mutation in the FUR1 gene, a large deletion in the FCY1 gene, and a point mutation in FCY1 leading to a truncated protein. The proteomic data indicated that these mutations resulted in the absence or reduction of crucial enzymes in resistant isolates. Genetic transformations confirmed the association between these mutations and 5-FC resistance. Resistance to 5-FC can develop during treatment and is closely tied to mutations in key metabolic enzymes. Understanding in vivo resistance development is crucial for combating resistance and enhancing patient outcomes.

Batf3-cDC1 control Th1 and fungicidal responses during cryptococcal meningitis: is this enough to control meningitis?

Dendritic cells are crucial for bridging innate and adaptive immunity. Cryptococcosis, caused by Cryptococcus neoformans and Cryptococcus gattii, is responsible for >15% of AIDS-related deaths. A recent study by Xu et al. showed that Batf3-dependent conventional type 1 dendritic (cDC1) cells are key players in generating IFNγ+ CD4+ T cell and fungicidal lung and brain tissue-resident responses during murine cryptococcosis, contributing to fungal clearance in the lungs and brain of mice (J. Xu, R. Hissong, R. Bareis, A. Creech, et al., mBio 15:e02853-23, 2024, https://doi.org/10.1128/mbio.02853-23). However, despite their critical role, the depletion of Batf3-dependent cDC1 cells did not significantly alter overall mouse survival or disease progression, highlighting the complex immune regulation required to survive cryptococcal infection and the need for further research in medical mycology.

Cerebrospinal fluid-induced stable and reproducible SERS sensing for various meningitis discrimination assisted with machine learning

Cerebrospinal fluid (CSF)-based pathogen or biochemical testing is the standard approach for clinical diagnosis of various meningitis. However, misdiagnosis and missed diagnosis always occur due to the shortages of unusual clinical manifestations and time-consuming shortcomings, low sensitivity, and poor specificity. Here, for the first time, we propose a simple and reliable CSF-induced SERS platform assisted with machine learning (ML) for the diagnosis and identification of various meningitis. Stable and reproducible SERS spectra are obtained within 30 s by simply mixing the colloidal silver nanoparticles (Ag NPs) with CSF sample, and the relative standard deviation of signal intensity is achieved as low as 2.1%. In contrast to conventional salt agglomeration agent-induced irreversible aggregation for achieving Raman enhancement, a homogeneous and dispersed colloidal solution is observed within 1 h for the mixture of Ag NPs/CSF (containing 110–140 mM chloride), contributing to excellent SERS stability and reproducibility. In addition, the interaction processes and potential enhancement mechanisms of different Ag colloids-based SERS detection induced by CSF sample or conventional NaCl agglomeration agents are studied in detail through in-situ UV–vis absorption spectra, SERS analysis, SEM and optical imaging. Finally, an ML-assisted meningitis classification model is established based on the spectral feature fusion of characteristic peaks and baseline. By using an optimized KNN algorithm, the classification accuracy of autoimmune encephalitis, novel cryptococcal meningitis, viral meningitis, or tuberculous meningitis could be reached 99%, while an accuracy value of 68.74% is achieved for baseline-corrected spectral data. The CSF-induced SERS detection has the potential to provide a new type of liquid biopsy approach in the fields of diagnosis and early detection of various cerebral ailments.

Deciphering prognostic indicators in non-HIV cryptococcal meningitis: Constructing and validating a predictive Nomogram model.

Cryptococcal meningitis (CM) is a well-recognized fungal infection, with substantial mortality in individuals infected with the human immunodeficiency virus (HIV). However, the incidence, risk factors, and outcomes in non-HIV adults remain poorly understood. This study aims to investigate the characteristics and prognostic indicators of CM in non-HIV adult patients, integrating a novel predictive model to guide clinical decision-making. A retrospective cohort of 64 non-HIV adult CM patients, including 51 patients from previous studies and 13 from the First Hospital of Shanxi Medical University, was analyzed. We assessed demographic features, underlying diseases, intracranial pressure, cerebrospinal fluid characteristics, and brain imaging. Using the least absolute shrinkage and selection operator (LASSO) method, and multivariate logistic regression, we identified significant variables and constructed a Nomogram prediction model. The model's calibration, discrimination, and clinical value were evaluated using the Bootstrap method, calibration curve, C index, goodness-of-fit test, receiver operating characteristic (ROC) analysis, and decision curve analysis. Age, brain imaging showing parenchymal involvement, meningeal and ventricular involvement, and previous use of immunosuppressive agents were identified as significant variables. The Nomogram prediction model displayed satisfactory performance with an akaike information criterion (AIC) value of 72.326, C index of 0.723 (0.592-0.854), and area under the curve (AUC) of 0.723, goodness-of-fit test P = 0.995. This study summarizes the clinical and imaging features of adult non-HIV CM and introduces a tailored Nomogram prediction model to aid in patient management. The identification of predictive factors and the development of the nomogram enhance our understanding and capacity to treat this patient population. The insights derived have potential clinical implications, contributing to personalized care and improved patient outcomes.

Bioavailability of a novel sustained-release pellet formulation of 5-flucytosine in healthy-fed participants for use in patients with cryptococcal meningitis.

Cryptococcal meningoencephalitis (CM) is an opportunistic fungal infection and a major cause of death among people living with human immunodeficiency virus in sub-Saharan Africa. 5-flucytosine (5-FC) is a unique, brain-permeable antifungal agent used to reduce mortality from CM and to prevent disease in individuals carrying cryptococcal antigen. 5-FC has a short plasma half-life, requiring 6-hourly oral dosing with an immediate-release (IR) formulation, a significant challenge in hospital and outpatient settings, risking a lack of compliance. We recently reported the relative bioavailability in fasting conditions of a sustained release (SR) oral pellet formulation of 5-FC. In this phase I study, we assessed the safety and pharmacokinetic profiles of the new 5-FC SR formulation in a single dose (2 × 3000 mg), relative to 5-FC IR tablets (Ancotil®; 1500 mg b.i.d.) in healthy participants in fed conditions. This randomized, two-period crossover study was conducted in South Africa to confirm the dose of the identified 5-FC SR formulation for a twice-daily 5-FC regimen in patients. Thirty-six healthy participants were included. All treatments were well tolerated and no serious adverse event was reported. Cmax and AUC(0-t) for the SR formulation (49.2 ± 10.49 μg/mL and 640.4 ± 126.4 h.μg/mL, respectively) were significantly higher than for the IR formulation (36.8 ± 7.61 μg/mL and 456.6 ± 72.8 h.μg/mL, respectively). A physiological based pharmacokinetic model (PBPK) predicted that under fasting conditions, 6000 mg SR pellets would show a good overlap with the IR product (3000 mg b.i.d), thus 6000 mg SR 5-FC b.i.d. in fasting conditions is recommended.