HIV-Related Cerebral Toxoplasmosis Revisited: Current Concepts and Controversies of an Old Disease

Risk factors for toxoplasmosis in people living with HIV in the Asia-Pacific region

INTRODUCTION

Toxoplasma gondii can cause symptomatic toxoplasmosis in immunodeficient hosts, including in people living with human immunodeficiency virus (PLWH), mainly because of the reactivation of latent infection. We assessed the prevalence of toxoplasmosis and its associated risk factors in PLWH in the Asia-Pacific region using data from the TREAT Asia Human Immunodeficiency Virus (HIV) Observational Database (TAHOD) of the International Epidemiology Databases to Evaluate AIDS (IeDEA) Asia-Pacific.

METHODS

This study included both retrospective and prospective cases of toxoplasmosis reported between 1997 and 2020. A matched case-control method was employed, where PLWH diagnosed with toxoplasmosis (cases) were each matched to two PLWH without a toxoplasmosis diagnosis (controls) from the same site. Sites without toxoplasmosis were excluded. Risk factors for toxoplasmosis were analyzed using conditional logistic regression.

RESULTS

A total of 269/9576 (2.8%) PLWH were diagnosed with toxoplasmosis in 19 TAHOD sites. Of these, 227 (84%) were reported retrospectively and 42 (16%) were prospective diagnoses after cohort enrollment. At the time of toxoplasmosis diagnosis, the median age was 33 years (interquartile range 28-38), and 80% participants were male, 75% were not on antiretroviral therapy (ART). Excluding 63 out of 269 people without CD4 values, 192 (93.2%) had CD4 ≤200 cells/μL and 162 (78.6%) had CD4 ≤100 cells/μL. By employing 538 matched controls, we found that factors associated with toxoplasmosis included abstaining from ART (odds ratio [OR] 3.62, 95% CI 1.81-7.24), in comparison to receiving nucleoside reverse transcriptase inhibitors plus non-nucleoside reverse transcriptase inhibitors, HIV exposure through injection drug use (OR 2.27, 95% CI 1.15-4.47) as opposed to engaging in heterosexual intercourse and testing positive for hepatitis B virus surface antigen (OR 3.19, 95% CI 1.41-7.21). Toxoplasmosis was less likely with increasing CD4 counts (51-100 cells/μL: OR 0.41, 95% CI 0.18-0.96; 101-200 cells/μL: OR 0.14, 95% CI 0.06-0.34; >200 cells/μL: OR 0.02, 95% CI 0.01-0.06), when compared to CD4 ≤50 cells/μL. Moreover, the use of prophylactic cotrimoxazole was not associated with toxoplasmosis.

CONCLUSIONS

Symptomatic toxoplasmosis is rare but still occurs in PLWH in the Asia-Pacific region, especially in the context of delayed diagnosis, causing advanced HIV disease. Immune reconstitution through early diagnosis and ART administration remains a priority in Asian PLWH.

Molecular diagnosis of human toxoplasmosis: the state of the art

Toxoplasma gondii (T. gondii) is an obligate intracellular apicomplexan protozoan that causes toxoplasmosis. Approximately one-third of the world's population is currently T. gondii-seropositive. Although most infections are symptomless, a few can produce retinal lesions and, in immunocompromised persons or when congenitally contracted, can progress to life-threatening central nervous system disseminated infections. Therefore, quick, and precise diagnosis is a must. Molecular techniques nowadays play a crucial role in toxoplasmosis diagnosis, particularly in immunocompromised patients or congenital toxoplasmosis. This review aimed to detail recent advancements in molecular diagnostics of T. gondii infections. The terms "Toxoplasmosis," "Molecular diagnostics," "PCR," "qPCR," "B1," and "rep529" were used to search the English-language literature. In developed nations, conventional PCR (PCR) and nested PCR have been supplanted by quantitative PCR (qPCR), although they are still widely employed in poor nations. The diagnosis of toxoplasmosis has been revolutionized by the emergence of molecular diagnostics. Unfortunately, there is still substantial interlaboratory variability. There is an immediate need for standardization to increase the comparability of results between laboratories and clinical trials.

Graphical abstract

A graphical abstract highlighting the summary of Toxoplasma molecular diagnostics, created using Biorender.com.

Primary central nervous system lymphoma: Imaging features and differential diagnosis

Primary central nervous system lymphoma (PCNSL) represents 5% of malignant primary brain tumors. The clinical presentation typically includes focal neurological symptoms, increased intracranial pressure, seizures, and psychiatric symptoms. Although histological examination remains the gold standard for diagnostic confirmation, non-invasive imaging plays a crucial role for the diagnosis. In immunocompetent individuals, PCNSL usually appears as a single, well-defined, supratentorial lesion with a predilection for periventricular areas, iso- or hypointense on T1- and T2-weighted magnetic resonance imaging, with restricted diffusion, slightly increased perfusion, and homogenous gadolinium-enhancement. Differential diagnoses include high-grade glioma and pseudotumoral demyelinating disease. In immunocompromised patients, PCNSL may present as multiple lesions, with a higher likelihood of hemorrhage and necrosis and less restricted diffusion than immunocompetent individuals. Differential diagnoses include neurotoxoplasmosis, progressive multifocal leukoencephalopathy, and cerebral abscess. Atypical forms of lymphoma are characterized by extra-axial lymphoma, lymphomatosis cerebri, and intravascular lymphoma. Extra-axial lymphoma presents as single or multiple extra-axial dural lesions with diffuse leptomeningeal contrast-enhancement. Lymphomatosis cerebri appears as an infiltrative and symmetric lesion, primarily affecting deep white matter and basal ganglia, appearing hyperintense on T2-weighted imaging, without significant contrast-enhancement or perfusion changes. Intravascular lymphoma presents as multiple rounded or oval-shaped "infarct-like" lesions, located cortically or subcortically. This study aims to highlight the imaging characteristics of PCNSL, focusing on magnetic resonance imaging and its differential diagnosis.

A Blast From the Past: Toxoplasmic Encephalitis As the Initial Presentation of HIV/AIDS

Many opportunistic infections (OIs) seen early in the human immunodeficiency virus (HIV) epidemic receded in prevalence with the advent of antiretroviral therapy (ART). Despite the availability of early detection and treatment of HIV as well as guidelines for near-universal screening, there remains a sizable population of individuals living with HIV who are not yet aware of their HIV status. These individuals are at risk for OIs such as toxoplasmosis, which would otherwise be preventable with ART and appropriate prophylaxis. Toxoplasmic encephalitis (TE) usually occurs in the late stages of HIV with acquired immunodeficiency syndrome (AIDS), but we present a case of a 38-year-old female with TE as the initial presentation of HIV/AIDS. Testing for the presence of an immunocompromising condition such as HIV is important in patients presenting with focal brain lesions as the differential diagnosis will change, and proper workup may spare invasive procedures such as a brain biopsy.

Calcified cerebral toxoplasmosis associated with recurrent perilesional edema causing neurological manifestations in an HIV-infected individual: case report with a decade-long follow-up

Four cases of people living with HIV/AIDS (PLWHA) with calcified cerebral toxoplasmosis associated with perilesional edema causing a single episode of neurological manifestations have recently been reported. Here, we describe the first detailed description of perilesional edema associated with calcified cerebral toxoplasmosis causing three episodes of neurological manifestations in a PLWHA, including seizures in two of them. These recurrences occurred over approximately a decade. Throughout this period, the patient showed immunological and virological control of the HIV infection, while using antiretroviral therapy regularly. This case broadens the spectrum of an emerging presentation of calcified cerebral toxoplasmosis, mimicking a well-described finding of neurocysticercosis in immunocompetent hosts.

Clinical profile of central nervous system space-occupying lesions and their association with CD4 counts in patients with HIV: A prospective observational study

Background

Neurological manifestations are one of the major concerns for patients with human immunodeficiency virus (HIV). The secondary spectrum includes space-occupying lesions (SOL), including tuberculoma, cryptococcosis, candidiasis, toxoplasmosis, primary central nervous system lymphoma (PCNSL), and progressive multifocal leukoencephalopathy (PML).

Aim

To assess the neurological manifestations, disease outcome, and their associations with cluster of differentiation 4 (CD4) counts in patients with HIV.

Materials and Methods

This single-center, prospective, observational study was performed in the Department of General Medicine of a tertiary care institute, over a period of 2 years (January 2017 to December 2018). The study included 150 known or newly diagnosed HIV patients with CNS SOL. The physical examination, laboratory investigations, and imaging were conducted on every patient, and the findings were noted.

Results

The patients mainly presented with hemiparesis (52%), had involvement of the frontal region (38.7%), and were diagnosed with tuberculoma (29.3%). Other diagnoses were toxoplasmosis (22.7%), PML (17.3%), PCNSL (15.3%), brain abscess (10%), and neurocysticercosis (5.3%). Of 150 patients, 136 (90.7%) were survivors, while 14 (9.3%) were non-survivors. The mean CD4 count was significantly less in patients with toxoplasmosis (P < 0.0001) and PCNSL (P = 0.02), and significantly higher in patients with tuberculoma (P < 0.0001) and brain abscess (P = 0.0009) relative to other causes of SOL. Moreover, the mean CD4 count was not significantly associated with survivors and non-survivors (P = 0.28).

Conclusion

In patients with HIV, CD4 count was significantly low in toxoplasmosis and PCNSL, and high in tuberculoma and brain abscess.

Anti-toxoplasma activity and DNA-binding of copper(II) and zinc(II) coordination compounds with 5-nitroimidazole-based ligands

Tetrahedral copper(II) and zinc(II) coordination compounds from 5-nitroimidazole derivatives, viz. 1-(2-chloroethyl)-2-methyl-5-nitroimidazole (cenz) and ornidazole 1-(3-chloro-2-hydroxypropyl)-2-methyl-5-nitroimidazole (onz), were synthesized and spectroscopically characterized. Their molecular structures were determined by X-ray diffraction studies. The complexes [Cu(onz)2X2], [Zn(onz)2X2], [Cu(cenz)2X2] and [Zn(cenz)2X2] (X- = Cl, Br), are stable in solution and exhibit positive LogD7.4 values that are in the range for molecules capable of crossing the cell membrane via passive difussion. Their biological activity against Toxoplasma gondi was investigated, and IC50 and lethal dose (LD50) values were determined. The ornidazole copper(II) compounds showed very good antiparasitic activity in its tachyzoite morphology. The interaction of the coordination compounds with DNA was examined by circular dichroism, fluorescence (using intercalating ethidium bromide and minor groove binding Hoechst 33258) and UV-Vis spectroscopy. The copper(II) compounds interact with the minor groove of the biomolecule, whereas weaker electrostatic interactions take place with the zinc(II) compounds. The spectroscopic data achieved for the two series of complexes (namely with copper(II) and zinc(II) as metal center) agree with the respective DNA-damage features observed by gel electrophoresis.

DeepBiomarker2: Prediction of Alcohol and Substance Use Disorder Risk in Post-Traumatic Stress Disorder Patients Using Electronic Medical Records and Multiple Social Determinants of Health

Prediction of high-risk events amongst patients with mental disorders is critical for personalized interventions. We developed DeepBiomarker2 by leveraging deep learning and natural language processing to analyze lab tests, medication use, diagnosis, social determinants of health (SDoH) parameters, and psychotherapy for outcome prediction. To increase the model's interpretability, we further refined our contribution analysis to identify key features by scaling with a factor from a reference feature. We applied DeepBiomarker2 to analyze the EMR data of 38,807 patients from the University of Pittsburgh Medical Center diagnosed with post-traumatic stress disorder (PTSD) to determine their risk of developing alcohol and substance use disorder (ASUD). DeepBiomarker2 predicted whether a PTSD patient would have a diagnosis of ASUD within the following 3 months with an average c-statistic (receiver operating characteristic AUC) of 0.93 and average F1 score, precision, and recall of 0.880, 0.895, and 0.866 in the test sets, respectively. Our study found that the medications clindamycin, enalapril, penicillin, valacyclovir, Xarelto/rivaroxaban, moxifloxacin, and atropine and the SDoH parameters access to psychotherapy, living in zip codes with a high normalized vegetative index, Gini index, and low-income segregation may have potential to reduce the risk of ASUDs in PTSD. In conclusion, the integration of SDoH information, coupled with the refined feature contribution analysis, empowers DeepBiomarker2 to accurately predict ASUD risk. Moreover, the model can further identify potential indicators of increased risk along with medications with beneficial effects.

Molecular diagnosis of opportunistic infections in the central nervous system of HIV-infected adults in Manaus, Amazonas

Background

Opportunistic infections in the central nervous system (CNS) of people with HIV/AIDS (PLWHA) remain significant contributors to morbidity and mortality, especially in resource-limited scenarios. Diagnosing these infections can be challenging, as brain imaging is non-specific and expensive. Therefore, molecular analysis of cerebrospinal fluid (CSF) may offer a more accurate and affordable method for diagnosing pathogens.

Methods

We conducted extensive real-time PCR testing (qPCR) on CSF to evaluate etiological agents in PLWHA with neurological manifestations. Primers targeting DNA from specific pathogens, including cytomegalovirus (CMV), herpes simplex virus (HSV), varicella-zoster virus (VZV), Epstein-Barr virus (EBV), John Cunningham virus (JCV), Toxoplasma gondii, and human T-lymphotropic virus types 1 and 2 (HTLV-1 and HTLV-2), were used.

Results

Cerebrospinal fluid samples revealed 90 pathogens (36.7%). Toxoplasma gondii was the most frequently detected pathogen, found in 22 samples (30.5%). Other pathogens included Cryptococcus sp. (7.7%), EBV (5.3%), CMV, VZV, and JCV (4.0% each).

Conclusion

Despite antiretroviral therapy and medical follow-up, opportunistic central nervous system infections remain frequent in PLWHA. Herpesviruses are commonly detected, but T. gondii is the most prevalent opportunistic pathogen in our study population. Therefore, molecular diagnosis is a crucial tool for identifying opportunistic infections, even in patients undergoing treatment.

Understanding the mechanisms underlying the disruption of the blood-brain barrier in parasitic infections

Parasites have a significant impact on the neurological, cognitive, and mental well-being of humans, with a global population of over 1 billion individuals affected. The pathogenesis of central nervous system (CNS) injury in parasitic diseases remains limited, and prevention and control of parasitic CNS infections remain significant areas of research. Parasites, encompassing both unicellular and multicellular organisms, have intricate life cycles and possess the ability to infect a diverse range of hosts, including the human population. Parasitic illnesses that impact the central and peripheral nervous systems are a significant contributor to morbidity and mortality in low- to middle-income nations. The precise pathways through which neurotropic parasites infiltrate the CNS by crossing the blood-brain barrier (BBB) and cause neurological harm remain incompletely understood. Investigating brain infections caused by parasites is closely linked to studying neuroinflammation and cerebral impairment. The exact molecular and cellular mechanisms involved in this process remain incomplete, but understanding the exact mechanisms could provide insight into their pathogenesis and potentially reveal novel therapeutic targets. This review paper explores the underlying mechanisms involved in the development of neurological disorders caused by parasites, including parasite-derived elements, host immune responses, and modifications in tight junctions (TJs) proteins.

A multimodality therapeutic application on Toxoplasma gondii encephalitis utilizing Spiramycin and 'de novo' Ferula asafetida in immunodeficient mice

This study investigated a 'de Novo' medicinal herb, Ferula asafetida (FA), against toxoplasma encephalitis either alone or combined with spiramycin (SP). Female Swiss-Webster mice (n = 72) were divided into three batches. Batch-I received no DMS to serve as an immunocompetent control, batch-II was immune-suppressed with the DMS (0.25 mg/g/day) for 14 days pre-infection, whilst batch-III was immune-suppressed with the DMS on the same day of infection. All experimental mice were inoculated with Toxoplasma gondii ME49 cysts (n = 75). Each batch was split into four subgroups: Mono-SP, mono-FA, combined drug (SP + FA), or neither. Therapies were administered on day zero of infection in batches (I and II) and 35 days post-infection in batch (III). Treatments lasted for 14 days, and mice were sacrificed 60 days post-infection. Histopathological changes, cysts load, and CD4 and CD8 T-cells were counted in brain tissues. The cyst-load count in mice receiving SP + FA was significantly (p < .0001) the least compared to the mono treatments in all protocols. Interestingly, the combined therapy demolished the T-cell subsets to zero in immunocompetent and immunocompromised infected mice. In conclusion, F. asafetida might be a powerfully natural, safe vehicle of SP in the digestive system and/or across the brain-blood barrier to control toxoplasmosis even through immunodeficient conditions.

Seroepidemiology of toxoplasmosis in pregnant women and detection of infection acquired during pregnancy in Cotonou, Benin

Assessing the prevalence of toxoplasmosis in pregnant women and the associated risk factors is the first step in defining policy for the prevention of congenital toxoplasmosis in a given population. An epidemiological study was conducted during prenatal consultations at the CHU-MEL of Cotonou (Benin) between September 2018 and April 2021 and recruited 549 pregnant women to determine the seroprevalence and potential factors associated with Toxoplasma gondii infection. Toxoplasma gondii IgG/IgM antibodies were detected using an enzyme-linked fluorescence assay (ELFA) technique, an IgG avidity test and an IgG/IgM comparative Western blot to diagnose the maternal toxoplasmosis serological status, the possibility of an infection acquired during pregnancy and congenital infection, respectively. Concomitantly, the participants answered a questionnaire investigating potential risk factors. Toxoplasmosis seroprevalence was estimated at 44.4% (95% CI 40.3-48.6) and the factors significantly associated with T. gondii seropositivity were: age over 30 years, multigravid women and contact with cats. The possibility of an infection acquired during the periconceptional period or the first trimester of pregnancy concerned six women [1.1% (95% CI 0.5-2.0)]. However, due to the low rate of serological controls in seronegative women, a significant proportion of women first tested during the 3rd trimester of pregnancy, and an insufficient sample size, the incidence of primary infection during pregnancy could not be determined. No cases of congenital transmission occurred in the newborns from the suspected cases of primary infection.

Differential Diagnosis of Tumor-like Brain Lesions

Purpose of Review

Tumor-like brain lesions are rare and commonly suggest a neoplastic etiology. Failure to rapidly identify non-neoplastic causes can lead to increased morbidity and mortality. In this review, we describe 10 patients who presented with atypical, non-neoplastic tumor-like brain lesions in which brain biopsy was essential for a correct diagnosis and treatment.

Recent Findings

There has been increasing recognition of autoimmune conditions affecting the nervous system, and many of those diseases can cause tumor-like brain lesions. Currently available reports of non-neoplastic tumor-like brain lesions are scarce. Most case series focus on tumefactive demyelinating lesions, and a comprehensive review including other neuroimmunological conditions such as CNS vasculitis, neurosarcoidosis, histiocytic and infectious etiologies is lacking.

Summary

We review the literature on tumor-like brain lesions intending to increase the awareness and differential diagnosis of non-neoplastic brain tumor mimics. We advocate for earlier brain biopsies, which, in our case series, significantly changed diagnosis, management, and outcomes.

Multiparametric imaging in the evaluation of intracerebral abscesses

Cerebral abscesses are uncommon space occupying lesions; they are associated with high morbidity and mortality, though are potentially treatable. Patients often present with non-specific symptoms and may have few clinical signs. Routine clinical imaging may not give a definite diagnosis, as the findings can be indistinguishable from those of other intracranial mass lesions. We review the role of advanced MR techniques to characterise brain abscesses and discuss the role of imaging in monitoring their response to the treatment.

Case report: A toxoplasmic encephalitis in an immunocompromised child detected through metagenomic next-generation sequencing

There exist numerous pathogens that are capable of causing infections within the central nervous system (CNS); however, conventional detection and analysis methods prove to be challenging. Clinical diagnosis of CNS infections often depends on clinical characteristics, cerebrospinal fluid (CSF) analysis, imaging, and molecular detection assays. Unfortunately, these methods can be both insensitive and time consuming, which can lead to missed diagnoses and catastrophic outcomes, especially in the case of infrequent diseases. Despite the application of appropriate prophylactic regimens and evidence-based antimicrobial agents, CNS infections continue to result in significant morbidity and mortality in hospital settings. Metagenomic next-generation sequencing (mNGS) is a novel tool that enables the identification of thousands of pathogens in a target-independent manner in a single run. The role of this innovative detection method in clinical pathogen diagnostics has matured over time. In this particular research, clinicians employed mNGS to investigate a suspected CNS infection in a child with leukemia, and unexpectedly detected Toxoplasma gondii.

Case

A 3-year-old child diagnosed with T-cell lymphoblastic lymphoma was admitted to our hospital due to a 2-day history of fever and headache, along with 1 day of altered consciousness. Upon admission, the patient's Glasgow Coma Scale score was 14. Brain magnetic resonance imaging revealed multiple abnormal signals. Due to the patient's atypical clinical symptoms and laboratory test results, determining the etiology and treatment plan was difficulty.Subsequently, the patient underwent next-generation sequencing examination of cerebrospinal fluid. The following day, the results indicated the presence of Toxoplasma gondii. The patient received treatment with a combination of sulfamethoxazole (SMZ) and azithromycin. After approximately 7 days, the patient's symptoms significantly improved, and they were discharged from the hospital with oral medication to continue at home. A follow-up polymerase chain reaction (PCR) testing after about 6 weeks revealed the absence of Toxoplasma.

Conclusion

This case highlights the potential of mNGS as an effective method for detecting toxoplasmic encephalitis (TE). Since mNGS can identify thousands of pathogens in a single run, it may be a promising detection method for investigating the causative pathogens of central nervous system infections with atypical features.

Evaluation of imaging methods in cerebral toxoplasmosis

Cerebral toxoplasmosis is a parasitic disease resulting, in most cases, from a reactivation of a latent cyst with Toxoplasma gondii. The disease mainly affects immunosuppressed individuals, such as HIV (human immunodeficiency virus)-infected patients. Diagnosis is based on specialized antibody testing, clinical symptoms, neuroimaging methods, and histological examination. The gold standard for diagnosis is a brain biopsy, but more often the response to treatment seen in clinical symptoms and neuroimaging studies is sufficient. The imaging features support the diagnosis of cerebral toxoplasmosis and help assess the effectiveness of treatment.

Concurrent Ocular and Cerebral Toxoplasmosis in a Liver Transplant Patient Treated with Anti-CD40 Monoclonal Antibody

Toxoplasma gondii, an obligate intracellular parasitic protozoon, usually causes a mild, acute infection followed by a latent asymptomatic phase with tissue cysts or a chronic form with recurrent retinochoroiditis. However, immunocompromised patients can cause disseminated disease due to the reactivation of the latent tissue cysts or due to a primary infection. Here, we present a rare case of bilateral ocular toxoplasmosis and concurrent subacute toxoplasma encephalitis in a 70-year-old patient on anti-CD40 treatment following his liver transplant. The diagnosis was confirmed by PCR of anterior chamber fluid and brain biopsy, and no other sites of disseminated disease were detected on PET-CT. The patient has been treated with sulfamethoxazole-trimethoprim 800/160 mg with virtually complete resolution of the neurological and ocular symptoms. Iatrogenic blockade of the CD40 pathway may elicit a particular susceptibility for CNS reactivation of T. gondii.

Application of Silver Nanoparticles in Parasite Treatment

Silver nanoparticles (AgNPs) are ultra-small silver particles with a size from 1 to 100 nanometers. Unlike bulk silver, they have unique physical and chemical properties. Numerous studies have shown that AgNPs have beneficial biological effects on various diseases, including antibacterial, anti-inflammatory, antioxidant, antiparasitic, and antiviruses. One of the most well-known applications is in the field of antibacterial applications, where AgNPs have strong abilities to kill multi-drug resistant bacteria, making them a potential candidate as an antibacterial drug. Recently, AgNPs synthesized from plant extracts have exhibited outstanding antiparasitic effects, with a shorter duration of use and enhanced ability to inhibit parasite multiplication compared to traditional antiparasitic drugs. This review summarizes the types, characteristics, and the mechanism of action of AgNPs in anti-parasitism, mainly focusing on their effects in leishmaniasis, flukes, cryptosporidiosis, toxoplasmosis, Haemonchus, Blastocystis hominis, and Strongylides. The aim is to provide a reference for the application of AgNPs in the prevention and control of parasitic diseases.

Metallic Nanoparticles and Core-Shell Nanosystems in the Treatment, Diagnosis, and Prevention of Parasitic Diseases

The usage of nanotechnology in the fight against parasitic diseases is in the early stages of development, but it brings hopes that this new field will provide a solution to target the early stages of parasitosis, compensate for the lack of vaccines for most parasitic diseases, and also provide new treatment options for diseases in which parasites show increased resistance to current drugs. The huge physicochemical diversity of nanomaterials developed so far, mainly for antibacterial and anti-cancer therapies, requires additional studies to determine their antiparasitic potential. When designing metallic nanoparticles (MeNPs) and specific nanosystems, such as complexes of MeNPs, with the shell of attached drugs, several physicochemical properties need to be considered. The most important are: size, shape, surface charge, type of surfactants that control their dispersion, and shell molecules that should assure specific molecular interaction with targeted molecules of parasites' cells. Therefore, it can be expected that the development of antiparasitic drugs using strategies provided by nanotechnology and the use of nanomaterials for diagnostic purposes will soon provide new and effective methods of antiparasitic therapy and effective diagnostic tools that will improve the prevention and reduce the morbidity and mortality caused by these diseases.

DeepBiomarker2: Prediction of alcohol and substance use disorder risk in post-traumatic stress disorder patients using electronic medical records and multiple social determinants of health

Introduction

Prediction of high-risk events amongst patients with mental disorders is critical for personalized interventions. In our previous study, we developed a deep learning-based model, DeepBiomarker by utilizing electronic medical records (EMR) to predict the outcomes of patients with suicide-related events in post-traumatic stress disorder (PTSD) patients.

Methods

We improved our deep learning model to develop DeepBiomarker2 through data integration of multimodal information: lab tests, medication use, diagnosis, and social determinants of health (SDoH) parameters (both individual and neighborhood level) from EMR data for outcome prediction. We further refined our contribution analysis for identifying key factors. We applied DeepBiomarker2 to analyze EMR data of 38,807 patients from University of Pittsburgh Medical Center diagnosed with PTSD to determine their risk of developing alcohol and substance use disorder (ASUD).

Results

DeepBiomarker2 predicted whether a PTSD patient will have a diagnosis of ASUD within the following 3 months with a c-statistic (receiver operating characteristic AUC) of 0·93. We used contribution analysis technology to identify key lab tests, medication use and diagnosis for ASUD prediction. These identified factors imply that the regulation of the energy metabolism, blood circulation, inflammation, and microbiome is involved in shaping the pathophysiological pathways promoting ASUD risks in PTSD patients. Our study found protective medications such as oxybutynin, magnesium oxide, clindamycin, cetirizine, montelukast and venlafaxine all have a potential to reduce risk of ASUDs.

Discussion

DeepBiomarker2 can predict ASUD risk with high accuracy and can further identify potential risk factors along with medications with beneficial effects. We believe that our approach will help in personalized interventions of PTSD for a variety of clinical scenarios.

The use of azithromycin and pyrimethamine for treatment of cerebral toxoplasmosis in human immunodeficiency virus-infected patients: a systematic review

Purpose

Toxoplasma gondii is a parasite that is widely distributed around the globe and can cause brain inflammation, particularly in immunosuppressed patients such as those diagnosed with human immunodeficiency virus (HIV). This paper reviews the efficacy of azithromycin and pyrimethamine combination therapy for cerebral toxoplasmosis in patients with HIV.

Methods

The scope of the studies included in this review was limited from 1992 to 2022, with studies primarily being randomized, controlled clinical trials available on online scientific journal databases. The authors screened eligible records for review, removing those that did not fit the inclusion and exclusion criteria. The risk of bias of the extracted data was analyzed through the Cochrane risk-of-bias tool for randomized trials.

Results

A broad search of major online databases such as PubMed, Medline, Google Scholar, and Cochrane using keywords, limit fields, and Boolean operators yielded 3,130 articles. After thoroughly screening the search results, two studies were included in this review. Results from the studies included in the review demonstrate that the combination therapy of azithromycin and pyrimethamine is favorable for cerebral toxoplasmosis. However, the net response is less effective than the standard treatment regimen (pyrimethamine and sulfadiazine).

Conclusion

The combination therapy of azithromycin and pyrimethamine is less effective than the standard treatment regimen for maintenance therapy for cerebral toxoplasmosis; thus, administering these medications for this indication must be met with caution.

Significant clinical outcome using pyrimethamine and clindamycin in cerebral toxoplasmosis with severe edema: a case report

Cerebral toxoplasmosis is a complication in HIV/AIDS patients that has recently increased in new cases due to increased HIV/AIDS incidents.

Case Presentation

An Indonesian male, 26-year old, complained of severe headache, left hemiparesis, and tremors. A brain computed tomography scan with contrast showed a large mass, extensive edema, and a significant midline shift resembling a brain tumor. The HIV test was positive, and CD4 decreased. The patient was treated with dexamethasone, mannitol, and pyrimethamine-clindamycin as therapy. After 2 weeks of treatment, the headache, hemiparesis, and tremor were clinically improved. Two months later, a brain computed tomography scan and MRI showed a good prognosis.

Clinical Discussion

The diagnosis of cerebral toxoplasmosis is based on a radiological examination and an HIV/AIDS test. Management of cerebral toxoplasmosis using pyrimethamine-clindamycin, while steroids are not recommended unless disproportionate cytotoxic edema is displayed and life-threatening.

Conclusion

A combination of pyrimethamine-clindamycin, and steroids can improve the prognosis of cerebral toxoplasmosis with severe edema.

Neurotoxoplasmosis in the Immunocompetent: A Rare Occurrence

Cerebral toxoplasmosis is a rare condition that predominantly affects immunocompromised people and is relatively uncommon in immunocompetent individuals. Acute toxoplasmosis primarily presents with focal and diffuse neurological signs and symptoms depending on the site of the lesion, the degree of local damage, and the severity of inflammation. In this report, we present a case of cerebral toxoplasmosis in an immunocompetent adult female who presented with an altered level of consciousness, fever, headache, and shortness of breath. This case highlights the diagnostic challenges that may arise when dealing with patients who have a wide range of clinical manifestations.

Single thalamic localization of brain toxoplasmosis mimicking brain tumors: Radiological and clinical findings

Background:

Cerebral toxoplasmosis is a relatively rare disorder that usually affects immunocompromised patients. The most common scenario occurs among human immunodeficiency virus (HIV)-positive patients. In those patients, toxoplasmosis is the most frequent cause of expansive brain lesion and continues to cause elevated morbidity and mortality. In typical cases of toxoplasmosis, both computed tomography and magnetic resonance imaging reveal single/ multiple nodular or ring-enhancing lesions with surrounding edema. Nevertheless, cases of cerebral toxoplasmosis with atypical radiological features have been reported. Diagnosis can be obtained by finding organisms in the cerebrospinal fluid or in stereotactic biopsy samples of the brain lesion. If untreated, cerebral toxoplasmosis is uniformly fatal, so prompt diagnosis is mandatory. A prompt diagnosis is necessary, as untreated cerebral toxoplasmosis is uniformly fatal.

Case Description:

We discuss imaging and clinical findings of a patient – not aware of being HIV-positive – with a solitary atypical brain localization of toxoplasmosis mimicking a brain tumor.

Conclusion:

Although relatively uncommon, neurosurgeons should be aware of the potential occurrence of cerebral toxoplasmosis. High index of suspicion is needed for timely diagnosis and prompt initiation of therapy.

Revisiting the Evidence Base for Modern-Day Practice of the Treatment of Toxoplasmic Encephalitis: A Systematic Review and Meta-Analysis

BACKGROUND

Toxoplasmic encephalitis (TE) is an opportunistic infection of people with human immunodeficiency virus (HIV) or other causes of immunosuppression. Guideline-recommended treatments for TE are pyrimethamine and sulfadiazine (P-S) or pyrimethamine and clindamycin (P-C); however, a substantial price increase has limited access to pyrimethamine. Consequently, some centers have transitioned to trimethoprim-sulfamethoxazole (TMP-SMX), an inexpensive alternative treatment. We aimed to review the evidence on the efficacy and safety of pyrimethamine-containing therapies vs TMP-SMX.

METHODS

We searched for and included randomized controlled trials (RCTs) and observational studies of TE treatments, regardless of HIV status. Data for each therapy were pooled by meta-analysis to assess the proportions of patients who experienced clinical and radiologic responses to treatment, all-cause mortality, and discontinuation due to toxicity. Sensitivity analyses limited to RCTs directly compared therapies.

RESULTS

We identified 6 RCTs/dose-escalation studies and 26 single-arm/observational studies. Identified studies included only persons with HIV, and most predated modern antiretroviral treatment. Pooled proportions of clinical and radiologic response and mortality were not significantly different between TMP-SMX and pyrimethamine-containing regimens (P > .05). Treatment discontinuation due to toxicity was significantly lower in TMP-SMX (7.3%; 95% confidence interval [CI], 4.7-11.4; I2 = 0.0%) vs P-S (30.5%; 95% CI, 27.1-34.2; I2 = 0.0%; P < .01) or P-C (13.7%; 95% CI, 9.8-18.8; I2 = 32.0%; P = .031). These results were consistent in analyses restricted to RCT data.

CONCLUSIONS

TMP-SMX appears to be as effective and safer than pyrimethamine-containing regimens for TE. These findings support modern RCTs comparing TMP-SMX to pyrimethamine-based therapies and a revisiting of the guidelines.

Cerebral toxoplasmosis in HIV-infected patients: a review

Toxoplasma gondii infection in the central nervous system commonly occurs among immunodeficient patients. Its prevalence is high in countries with a high burden of HIV and low coverage of antiretroviral drugs. The brain is one of the predilections for T. gondii infection due to its low inflammatory reaction, and cerebral toxoplasmosis occurs solely due to the reactivation of a latent infection rather than a new infection. Several immune elements have recently been recognized to have an essential role in the immunopathogenesis of cerebral toxoplasmosis. Although real-time isothermal amplification, next-generation sequencing, and enzyme-linked aptamer assays from blood samples have been the recommended diagnostic tools in some in-vivo studies, a combination of clinical symptoms, serology examination, and neuroimaging are still the daily standard for the presumptive diagnosis of cerebral toxoplasmosis and early anti-toxoplasma administration. Clinical trials are needed to find a new therapy that is less likely to affect folate synthesis, have neuroprotective properties, or cure the latent phase of infection. The development of a vaccine is being extensively tested in animals, but its efficacy and safety for humans are still not proven.

Advances and Challenges in Diagnostics of Toxoplasmosis in HIV-Infected Patients

Toxoplasma gondii is a worldwide distributed protozoan parasite. This apicomplexan parasite infects one-third of the population worldwide, causing toxoplasmosis, considered one of the neglected parasitic infections. In healthy humans, most infections are asymptomatic. However, in immunocompromised patients, the course of the disease can be life-threatening. Human immunodeficiency virus (HIV)-infected patients have a very high burden of Toxoplasma gondii co-infection. Thus, it is essential to use modern, sensitive, and specific methods to properly monitor the course of toxoplasmosis in immunodeficient patients.

CEREBRAL TOXOPLASMOSIS IN THE COURSE OF HIV INFECTION - CASE STUDY

OBJECTIVE

Aim: To the aim of our study is to draw attention to the need to take into account HIV infection and its complications, such as CNS toxoplasmosis, in the differential diagnosis of people presenting with impaired consciousness. We analyzed our patient's medical records and available statistical data on HIV infection, as well as literature on nervous system involvement in the course of AIDS.

PATIENTS AND METHODS

Materials and Methods: In our paper, we present the case of a 43-year-old male who was admitted to a neurological ward due to impaired consciousness. Diagnostic imaging and laboratory tests were conducted, and patient was diagnosed with toxoplasmosis in the course of AIDS.

CONCLUSION

Conclusions: HIV infection is a global public health problem. In the absence or ineffectiveness of treatment, it leads to profound immunodeficiency and, consequently, opportunistic infections. One of them is the reactivation of the latent Toxoplasma gondii infection. It is the most common cause of extensive cerebral lesions in patients infected with the HIV virus. In these cases, MRI reveals numerous scattered ring-enhancing lesions. The symptoms are non-specific: headaches, impaired consciousness, convulsions, behavioral changes, and focal neurological deficits. The onset of neurological symptoms may be the first clinically relevant manifestation of AIDS. It is key to diagnose such patients as soon as possible and treat them accordingly.

Inhibition of Toxoplasma gondii by 1,2,4-triazole-based compounds: marked improvement in selectivity relative to the standard therapy pyrimethamine and sulfadiazine

A safer treatment for toxoplasmosis would be achieved by improving the selectivity profile of novel chemotherapeutics compared to the standard therapy pyrimethamine (PYR) and sulfadiazine (SDZ). We previously reported on the identification of the compounds with imidazole-thiosemicarbazide scaffold as potent and selective anti-Toxoplasma gondii (T. gondii) agents. In our current research, we report on the optimisation of this chemical scaffold leading to the discovery cyclic analogue 20 b with s-triazole core structure. This compound displayed prominent CC₃₀ to IC₅₀ selectivity index (SI) of 70.72, making it 160-fold more selective than SDZ, 11-fold more selective than PYR, and 4-fold more selective than trimethoprim (TRI). Additionally, this compound possesses prerequisite drug-like anti-Toxoplasma properties to advance into preclinical development; it showed ability to cross the BBB, did not induce genotoxic and haemolytic changes in human cells, and as well as it was characterised by low cellular toxicity.

Central nervous system aspergillosis misdiagnosed as Toxoplasma gondii encephalitis in a patient with AIDS: a case report

Background

Patients with acquired immunodeficiency syndrome (AIDS) tend to suffer from several central nervous system (CNS) infections due to hypoimmunity. However, CNS aspergillosis (CNSAG) is extremely rare and difficult to diagnose. Thus, it is easily misdiagnosed.

Case presentation

We reported a 47-year-old male AIDS patient with ghosting vision and anhidrosis on the left head and face. He was accordingly diagnosed with Toxoplasma gondii encephalitis (TE) at other hospitals, for which he received regular anti-Toxoplasma gondii and anti-human immunodeficiency virus (anti-HIV) treatment. Then, the patient was transferred to our hospital due to a lack of any improvement with the prescribed treatment. The patient's neurological examination revealed no abnormalities at admission, only a slight change in the cerebrospinal fluid. His cranial magnetic resonance imaging (MRI) revealed multiple abnormal signals in the brain parenchyma, and his blood was positive for Toxoplasma gondii IgG antibody. The initial diagnosis at our hospital was also TE. Considering the poor efficacy of anti-TE treatment, cerebrospinal fluid metagenomics next-generation sequencing (mNGS) was performed, but no pathogenic bacteria were detected. However, Aspergillus fumigatus was detected in the cerebrospinal fluid via targeted next-generation sequencing (tNGS) and bronchoalveolar alveolar lavage fluid via mNGS. The diagnosis was accordingly revised to CNSAG combined with his other clinical manifestations. After administering voriconazole antifungal therapy, the patient’s symptoms were relieved, with improved absorption of the intracranial lesions.

Conclusions

The present case experience indicates the need for clinicians to strengthen their understanding of CNSAG. Moreover, for patients with diagnostic difficulties, early mNGS and tNGS (using biological samples with only a few pathogens) are helpful for early diagnosis and treatment, potentially allowing patients to achieve favorable outcomes.

Dynamic immune profile in French toxoplasmosis patients

BACKGROUND

Toxoplasma gondii infection is usually benign in Europe due to the strong predominance of type II strains. Few studies have been conducted to examine the immunological course of infection in humans and have yielded conflicting results, maybe influenced by heterogeneous parasite strains.

METHODS

We measured 23 immune mediators in 39, 40, and 29 sera of French non-infected, acutely infected, and chronically infected immunocompetent pregnant women, respectively.

RESULTS

Four different cytokine patterns were identified regarding their dynamics through infection phases. For eleven of the cytokines, IFN-β, IFN-γ, IL-4, IL5, IL-6, IL-10, IL-12, IL-15, CXCL9, CCL2 and CSF2, the serum levels were significantly elevated during acute infection. The inflammatory mediators IL-1β, IL-17A, IL-18, TNF-α and CSF3 remained unchanged during acute infection, while they were significantly lower in chronically infected compared to non-infected patients. As for the anti-inflammatory cytokines TGF-β and CCL5, their levels remained significantly elevated during chronic infection. We also observed a significant negative correlation of several cytokine concentrations with IgG levels, indicating a rapid decline of serum concentrations during the acute phase.

DISCUSSION

These results indicate an anti-inflammatory pattern in chronically infected patients in a type II dominated setting and demonstrate the highly dynamic immune situation during acute infection.

Cerebral toxoplasmosis in a patient with combined variable immunodeficiency

Background:

Cerebral toxoplasmosis is an opportunistic infection in patients but has rarely been described in the setting of compromised humoral immunodeficiency. Prompt diagnosis and treatment of the infection is critical in the care of these patients. Medical management is the mainstay of treatment of the infection. There have been very few reports of surgical management of cerebral toxoplasmosis.

Case Description:

We describe the case of a 40-year-old male who presented with headache, memory deficits, weight loss, and left-sided weakness in the setting of a known but undiagnosed brain lesion identified 1 month prior. Imaging demonstrated a right basal ganglia lesion which was initially presumed to be malignancy. On further workup including a positive serum test and biopsy including polymerase chain reaction analysis, diagnosis was confirmed as toxoplasmosis. On further investigation, he was found to have deficiencies in immunoglobulins consistent with common variable immunodeficiency (CVID). The patient underwent craniotomy with surgical debulking as repeat imaging showed increased size of mass with new satellite lesions and worsening hydrocephalus.

Conclusion:

Cerebral toxoplasmosis is an important differential to consider in cases of intracerebral lesions and should not necessarily be excluded in the absence of compromised cellular immunity. In cases where there is no immunocompromised state and malignancy cannot immediately be established, CVID should be considered as an etiology. Due to the subtlety of CVID diagnosis, careful attention should be paid to history taking and workup for CVID should be considered as soon as possible. Surgical removal of these lesions in conjunction with medications is an effective treatment option.

PLGA Nanoparticles as an Efficient Platform in Protein Vaccines Against Toxoplasma gondii

BACKGROUND

Toxoplasma gondii (T. gondii) as an obligatory intracellular is widespread all over the world and causes considerable concerns in immunocompromised patients by developing toxoplasmic encephalitis and in pregnancy because of serious consequences in the fetus. Although vaccination is the only approach to overcome toxoplasmosis, there is no commercially available human vaccine against T. gondii.

PURPOSE

The remarkable features of poly (lactic-co-glycolic acid) (PLGA) particles have brought up the application of PLGA as a promising vaccine delivery vehicle against T. gondii and other intracellular parasites. This review focuses on the application of the PLGA delivery system in the development of preventive vaccines against T. gondii.

METHODS

In this study, all required data were collected from articles indexed in English databases, including Scopus, PubMed, Web of Science, Science Direct, and Google Scholar.

RESULT

Immunity against T. gondii, characteristics of PLGA particles as a delivery vehicle, and all researches on particulate PLGA vaccines with different T. gondii antigens and DNA against were discussed and their efficacies in conferring protection against a lethal challenge based on increased survival or reduced brain cyst loads have been shown.

CONCLUSION

Although various levels of protection against lethal challenge have been achieved through PLGA-based vaccinations, there is still no complete protection against T. gondii infection. Surprisingly, the application of surface modifications of PLGA particles by mucoadhesive polymers, cationic agents, DCs (dendritic cells) targeting receptors, specialized membranous epithelial cells (M-cells), and co-delivery of the desired antigen along with toll-like receptor ligands would be a revolutionized vaccine strategy against T. gondii.

Hemorrhagic Lesions in the Central Nervous System: Toxoplasmosis in a Person Living With Human Immunodeficiency Virus Infection and Acquired Immunodeficiency Syndrome

Central nervous system (CNS) toxoplasmosis is one of the common causes of hemorrhagic brain lesions in people living with HIV and AIDS (PLWHA), resulting in high mortality and morbidity. It has a broad clinical and neuro-radiological spectrum, which may or may not be limited to typical findings of focal and subacute neurological deficits or ring-enhancing lesions in the basal ganglia. Here, we present a case of a patient who is a newly detected person living with HIV and AIDS with a low CD₄ cell count and classical imaging findings of central nervous system toxoplasmosis on his magnetic resonance imaging (MRI) of the brain. The incidence of opportunistic infections has been reduced after introducing highly active antiretroviral therapy (HAART); this case will be helpful to clinicians in identifying CNS toxoplasmosis as it has classical imaging findings on the MRI brain.

Biogenic silver nanoparticles reduce Toxoplasma gondii infection and proliferation in RAW 264.7 macrophages by inducing tumor necrosis factor-alpha and reactive oxygen species production in the cells

Owing to the serious adverse effects caused by pyrimethamine and sulfadiazine, the drugs commonly used to treat toxoplasmosis, there is a need for treatment alternatives for this disease. Nanotechnology has enabled significant advances toward this goal. This study was conducted to evaluate the activity of biogenic silver nanoparticles (AgNp-Bio) in RAW 264.7 murine macrophages infected with the RH strain of Toxoplasma gondii. The macrophages were infected with T. gondii tachyzoites and then treated with various concentrations of AgNp-Bio. The cells were evaluated by microscopy, and culture supernatants were collected for ELISA determination of their cytokine concentration. Treatment with 6 μM AgNp-Bio reduced the infection and parasite load in infected RAW 264.7 macrophages without being toxic to the cells. The treatment also induced the synthesis of reactive oxygen species and tumor necrosis factor-alpha (both pro-inflammatory mediators), which resulted in ultrastructural changes in the tachyzoites and their intramacrophagic destruction. Our findings suggest that AgNp-Bio affect T. gondii tachyzoites by activating microbicidal and pro-inflammatory mechanisms and may be a potential alternative treatment for toxoplasmosis.

Cerebral Toxoplasmosis As the Initial Presentation of HIV: A Case Series

The HIV epidemic afflicts millions across the globe, and Sub-Saharan countries bear a disproportionately high burden. Cerebral toxoplasmosis is commonly seen as the disease progresses but is rarely ever reported as the initial manifestation of HIV. The clinical presentation, co-existing risk factors, and outcomes remain underreported. The objective of this article is to report cerebral toxoplasmosis as the initial manifestation of HIV. This is a consecutive series of three patients that presented to a community hospital in Pennsylvania, United States, with a variety of neuropsychiatric symptoms and were found to have cerebral toxoplasmosis. The findings are compared with existing literature on cerebral toxoplasmosis as the initial manifestation of HIV. Cerebral toxoplasmosis as the initial manifestation of HIV is a rarely reported phenomenon. Hyponatremia may be linked with this disease-complex, although further studies are warranted to establish a causal relationship. Co-infection with hepatitis viruses is also a common finding in these patients.

Case Report: Calcified Cerebral Toxoplasmosis Associated with Perilesional Edema in People Living with HIV/AIDS: Case Series of a Presentation Mimicking Neurocysticercosis

Perilesional edema, associated or not with neurological manifestations, is a well-characterized finding in cases of calcified neurocysticercosis. There are no previous reports of HIV-related calcified toxoplasmosis that mimics this presentation of neurocysticercosis. We report on five patients, four of them with new-onset neurological manifestations, who showed brain calcifications associated with perilesional edema. All cases had a history of HIV-related toxoplasmosis and current virological and immunological control of HIV infection. Similar to neurocysticercosis, brain calcified toxoplasmosis may cause perilesional edema and symptoms in people living with HIV/AIDS.

Early Antiretroviral Therapy in AIDS Patients Presenting With Toxoplasma gondii Encephalitis Is Associated With More Sequelae but Not Increased Mortality

Background

Evidence on the optimal time to initiate antiretroviral therapy (ART) in the presence of toxoplasmic encephalitis (TE) is scarce. We compared the impact of early vs. delayed ART initiation on mortality and neurologic complications at discharge in a Brazilian population co-infected with HIV and TE.

Methods

We retrospectively evaluated data from 9 years of hospitalizations at a referral center in Manaus, Amazonas. All ART-naïve hospitalized patients were divided into early initiation treatment (EIT) (0-4 weeks) and delayed initiation treatment (DIT) (>4 weeks). The groups were compared using chi-square test and mortality at 16 weeks.

Results

Four hundred sixty nine patients were included, of whom 357 (76.1%) belonged to the EIT group. The median CD4⁺ lymphocyte count and CD4⁺/CD8⁺ ratio were 53 cells/mm³ and 0.09, respectively. Mortality rate and presence of sequelae were 4.9% (n = 23) and 41.6% (n = 195), respectively. Mortality was similar between groups (p = 0.18), although the EIT group had the highest prevalence of sequelae at discharge (p = 0.04). The hazard ratio for death at 16 weeks with DIT was 2.3 (p = 0.18). The necessity for intensive care unit admission, mechanical ventilation, and cardiopulmonary resuscitation were similar between groups.

Conclusion

In patients with AIDS and TE, early ART initiation might have a detrimental influence on the occurrence of sequelae.

Impact of Plant-Based Foods and Nutraceuticals on Toxoplasma gondii Cysts: Nutritional Therapy as a Viable Approach for Managing Chronic Brain Toxoplasmosis

Toxoplasma gondii is an obligate intracellular parasite that mainly infects warm-blooded animals including humans. T. gondii can encyst and persist chronically in the brain, leading to a broad spectrum of neurological sequelae. Despite the associated health threats, no clinical drug is currently available to eliminate T. gondii cysts. In a continuous effort to uncover novel therapeutic agents for these cysts, the potential of nutritional products has been explored. Herein, we describe findings from in vitro and in vivo studies that support the efficacy of plant-based foods and nutraceuticals against brain cyst burden and cerebral pathologies associated with chronic toxoplasmosis. Finally, we discuss strategies to increase the translatability of preclinical studies and nutritional products to address whether nutritional therapy can be beneficial for coping with chronic T. gondii infections in humans.

Analysis of Deaths among HIV-Infected Patients Hospitalized in 2009–2018 in Main Centre of Infectious Disease in Region of Lower Silesia in Poland, Detailing Lesions in the Central Nervous System

Background and Objectives: Patients living with HIV (PLWH), especially those diagnosed too late or not receiving treatment with antiretroviral drugs in the stage of advanced immunodeficiency AIDS for various reasons, develop additional opportunistic infections or AIDS-defining diseases that may contribute directly to the death of these patients. Material and Methods: In this work, we focused on disorders of the central nervous system (CNS) by retrospectively analyzing the symptoms, clinical and autopsy diagnoses of patients diagnosed with HIV infection who died in the provincial specialist hospital in the Lower Silesia region in Poland. Results: The autopsy was performed in 27.4% cases. The cause of death was determined to be HIV-related/AIDS-associated in 78% patients. The most common AIDS-defining CNS diseases in our cohort were toxoplasmosis and cryptococcosis. Conslusions: The presented results of the most common causes of changes in the central nervous system among deceased HIV-infected patients are comparable to the results of studies by other scientists cited in the publication.

Eight-and-a-Half Syndrome Secondary to Neurotoxoplasmosis: A Rare Case Report

Eight-and-a-half syndrome (EHS) is a neuro-ophthalmological condition characterised by horizontal gaze palsy, internuclear ophthalmoplegia, and ipsilateral facial palsy. Albeit rare, EHS is a well reported condition in the literature, with several reports presenting multiple aetiologies. Infarcts are the cause in more than half the cases. Human immunodeficiency virus (HIV)-related cases are rare, and are probably underreported in low- and middle-income countries. In this report, we describe EHS secondary to neurotoxoplasmosis in a 40-year-old HIV-positive Brazilian man. EHS secondary to neurotoxoplasmosis is a challenging diagnosis, with important differential diagnoses, notably for HIV patients.

microRNA-155 Expression and Butyrylcholinesterase Activity in the Liver Tissue of Mice Infected with Toxoplasma gondii (Avirulent and Virulent Strains)

PURPOSE

Toxoplasma gondii is an apicomplexan parasite that exhibits distinct strain-related virulence patterns in mice. It can induce hepatic inflammation. The present study investigated MicroRNA-155 (miRNA-155) expression and butyrylcholinesterase (BChE) activity in the liver tissue of mice infected with virulent and avirulent strains of T. gondii.

METHODS

Mice groups included: Group (A), uninfected controls; Group (B), infected with T. gondii avirulent strain (ME-49) and euthanized 7, 27, 47, or 67 days post-infection (pi); Group (C), infected by T. gondii virulent strain (RH) and euthanized 7 days pi; and Group (D), infected by T. gondii virulent strain (RH), treated 24 h pi with sulfamethoxazole-trimethoprim (150 mg/Kg/day and 30 mg/Kg/day, respectively) and euthanized 5, 10, or 20 days pi. miRNA-155 expression was estimated in the liver tissue using the reverse transcription real-time polymerase chain reaction and the ΔΔC_t method. BChE activity was estimated in liver homogenates by Ellman's colorimetric method. Liver sections were examined histopathologically.

RESULTS

revealed a significant elevation in miRNA-155 expression and a significant reduction of BChE activity in all the infected untreated groups compared to the uninfected mice. In group B, the maximum upregulation of miRNA-155 expression and the least reduction in BChE activity were detected 7 days pi. In group D, complete restoration of normal levels occurred 20 days pi. Liver sections showed distinct histopathological patterns with detection of intracellular tachyzoites in group B.

CONCLUSION

miRNA-155 and BChE play a role in regulating host-parasite interaction in toxoplasmosis and may contribute to the pathogenesis of T. gondii induced hepatic damage.

Differentiation of Acquired Immune Deficiency Syndrome Related Primary Central Nervous System Lymphoma from Cerebral toxoplasmosis with Use of Susceptibility-Weighted Imaging and Contrast Enhanced 3D-T1WI

BACKGROUND

We aimed to investigate whether susceptibility-weighted imaging (SWI) and contrast-enhanced 3D-T1WI can differentiate Acquired Immune Deficiency Syndrome-Related Primary Central Nervous System Lymphoma (AR-PCNSL) from cerebral toxoplasmosis.

METHODS

This was a prospective cohort study. 20 AIDS patients were divided into AR-PCNSL group (13 cases) and cerebral toxoplasmosis group (7 cases) based on pathology results. We analyzed the appearance of lesions on SWI and enhanced 3D T1WI and ROC curves in the diagnosis of AR-PCNSL and cerebral toxoplasmosis.

RESULTS

Cerebral toxoplasmosis was more likely to show annular enhancement (p = 0.002) and complete smooth ring enhancement (p = 0.002). It was also more likely to present a complete, smooth low signal intensity rim (LSIR) (p = 0.002) and an incomplete, smooth LSIR (p = 0.019) on SWI. AR-PCNSL was more likely to present an incomplete, irregular LSIR (p < 0.001) and irregular central low signal intensity (CLSI) (p<0.001) on SWI. The areas under the ROC curve of the SWI-ILSS grade and enhanced volume on 3D-T1WI were 0.872 and 0.862, respectively.

CONCLUSION

A higher SWI-ILSS grade and larger 3D-T1WI volume enhancement were diagnostic for AR-PCNSL. SWI and CE 3D-T1WI were useful in the differential diagnosis of AR-PCNSL and cerebral toxoplasmosis.

Evaluation of neuroimaging findings in thalamic lesions: what can we think?

The diseases that affect the thalamus are heterogeneous in their etiologies, including infectious, inflammatory, vascular, toxic-metabolic, and neoplastic causes. It is often difficult to make the clinical differentiation between different entities. Within this context, computed tomography and magnetic resonance imaging have come to be of fundamental importance for defining the etiology and planning the treatment. In this pictorial essay, we will illustrate the main causes of diseases affecting the thalamus, discussing the possible differential diagnoses, as well as the most relevant imaging aspects.

Biogenic silver nanoparticles (AgNp-Bio) reduce Toxoplasma gondii infection and proliferation in HeLa cells, and induce autophagy and death of tachyzoites by apoptosis-like mechanism

Toxoplasma gondii is a protozoan parasite that can cause severe and debilitating diseases, especially in immunocompromised individuals. The available treatment is based on drugs that have low efficacy, high toxicity, several adverse effects, and need long periods of treatment. Thus, the search for therapeutic alternatives is urgently needed. Biogenic silver nanoparticles (AgNp-Bio) have been associated with several biological effects, as antiproliferative, pro-apoptotic, antioxidant, antiviral, antifungal, and antiprotozoal activity. Thus, the objective was evaluating AgNp-Bio effect on HeLa cells infected with T. gondii (RH strain). First, nontoxic AgNp-Bio concentrations for HeLa cells (1.5 - 6 µM) were determined, which were tested on cells infected with T. gondii. A significant reduction in infection, proliferation, and intracellular parasitic load was observed, also an increase in ROS and IL-6. Additionally, the evaluation of the action mechanisms of the parasite showed that AgNp-Bio acts directly on tachyzoites, inducing depolarization of the mitochondrial membrane, ROS increase, and lipid bodies accumulation, as well as triggering an autophagic process, causing damage to the parasite membrane, and phosphatidylserine exposure. Based on this, it was inferred that AgNp-Bio affects T. gondii by inducing immunomodulation and microbicidal molecules produced by infected cells, and acts on parasites, by inducing autophagy and apoptosis.

Molecular diagnosis of toxoplasmosis: recent advances and a look to the future

INTRODUCTION

Toxoplasmosis is a globally distributed parasitic infection that can be particularly severe when opportunistic or congenital. Its diagnosis requires accurate and rapid techniques that rely mainly on serology and molecular methods.

AREAS COVERED

The aim of this review was to discuss the positioning of the molecular diagnosis of toxoplasmosis according to the different clinical situations possibly resulting from infection with T. gondii, and to detail recent developments in this technique. The English and French literature were searched with the following keywords: 'Toxoplasmosis', "Molecular diagnosis" and 'PCR'.

EXPERT OPINION

Molecular techniques have revolutionized the diagnosis of toxoplasmosis, and practices have considerably evolved over the past decades. However, there is still a high degree of inter-laboratory heterogeneity which impairs comparisons between results and studies. Efforts to standardize practices are underway.