Toxoplasmosis In Immunocompromised Patients Research Articles

Development of a LAMP method with lateral flow DNA chromatography to diagnose toxoplasmosis in immunocompromised patients

BackgroundRapid and accurate diagnosis of toxoplasmosis is critical, particularly for immunocompromised patients. Several molecular methods could have value for toxoplasmosis diagnosis, but often require sophisticated and expensive equipment, and as such are impractical for use in resource-limited countries. Our study aimed to develop a new rapid diagnostic test for toxoplasmosis that can be used in developed countries as well as low- or middle-income countries.MethodsCommon primers for conventional loop-mediated isothermal amplification (LAMP) and the new LAMP DNA chromatography method were designed based on a 529-bp repeat present in Toxoplasma gondii genomic DNA. A total of 91 clinical samples from 44 patients suspected of having toxoplasmosis who were treated at several hospitals across Japan were tested using the new LAMP DNA chromatography method, conventional LAMP, and nested PCR and the sensitivity and specificity of the methods was compared.ResultsThe LAMP DNA chromatography method showed better sensitivity and specificity (68.2% and 100%, respectively) compared with the nested PCR (45.4% and 100%, respectively) and conventional LAMP (63.6% and 100%, respectively) methods for diagnosis of toxoplasmosis in immunocompromised patients. LAMP DNA chromatography also has better sensitivity and specificity (75% and 100%, respectively) than nested PCR (50.0% and 93.5%, respectively) and conventional LAMP (62.5% and 100%, respectively) to diagnose toxoplasma encephalitis using CSF samples.ConclusionWe developed a LAMP DNA chromatography method to detect T. gondii DNA in clinical samples. This method also successfully detected T. gondii DNA in CSF from patients with toxoplasma encephalitis. This newly developed method can be a valuable rapid diagnostic test for toxoplasmosis in a range of settings, including resource-limited areas like those in low- or middle-income countries.

Imaging Aspects of Cerebral Toxoplasmosis in Immunocompromised Patients

This is the first hypothesis to be raised, especially if the patient is not taking prophylactic treatment. Lesions are generally multiple, localized in the grey nuclei and cortico-subcortical regions (hematogenous dissemination), and may bleed spontaneously. The mass effect associated with peri lesional edema is often major, even if the lesion is small. Contrast is often annular, with the center of the lesion in hypersignal or T2 hyposignal, often remaining in diffusion hyposignal. After treatment, a scar in the form of a small, stable annular contrast pattern may persist for years.

Toxoplasma gondii infection positively associated with schizophrenia: Evidences from UK Biobank cohort and case-controlled studies

Toxoplasma gondii (T. gondii) is an opportunistic pathogen affecting about 1/3 of world population. While often asymptomatic in immunocompetent individuals, it can lead to severe toxoplasmosis in immunocompromised patients. Recent research has unveiled a potential link between T. gondii infection and neuropsychiatric diseases. We implemented both a cohort study and a case control study to further identify this association. In the cohort study, we analyzed data from the UK Biobank database, which included 8814 individuals tested for T. gondii SAG1 antibodies and free of neuropsychiatric disorders at baseline. Among them, 22.52% (n = 1985) tested positive for SAG1 antibody. Over an average follow-up period of 12.26 years, Cox proportional hazards models and logistic regression analysis revealed a significant association between the SAG1 seropositivity at baseline and the incidence of schizophrenia (HR: 5.89; 95% CI: 1.69–20.53). In our case-control study, 239 patients diagnosed with schizophrenia and 455 healthy individuals were involved. Using the modified agglutination test (MAT) to detect T. gondii antibodies, logistic regression analysis showed a higher prevalence of T. gondii infection among schizophrenia patients (10.04%) compared to healthy controls (3.74%). T. gondii infection emerged as a significant risk factor for schizophrenia (OR: 3.33; 95% CI: 1.68–6.61). However, our investigations did not reveal a robust association between T. gondii infection and other neuropsychiatric conditions, including Alzheimer's disease, dementia, anxiety, depression, neurodegenerative disorders, and peripheral neurological disorders such as neurological and plexus disorders.

The problem of toxoplasmosis in outpatient practice. Part I. Toxoplasmosis in immunocompromised patients

Toxoplasmosis remains one of the most common opportunistic infections in immunocompromised patients, primarily in people living with HIV. An increase in the number of requests for medical care by patients with HIV infection as the disease progresses determines the need for knowledge of outpatient therapists and general practitioners of decision-making algorithms for suspected toxoplasmosis in such patients. The main clinical manifestations of toxoplasmosis in patients with immunodeficiency states, the formulation of a preliminary diagnosis, and the routing algorithm are given.

Seroepidemiology of Toxoplasmosis in Hemodialysis Patients in Senegal

Toxoplasmosis in immunocompromised patients results in either reactivation of latent toxoplasmosis or acute infection. In the framework of the kidney transplantation program in Senegal, the serological screening of potential pre-transplant and transplanted patients can prevent the disease. This study aimed to assess the seroprevalence of toxoplasmosis in a cohort of hemodialysis patients, candidates for kidney transplantation. To this end, a multicentre cross-sectional study was conducted in 2020 in six dialysis units from five regions. Blood samples and sociodemographic data were collected from each patient. IgG and IgM against T. gondii antibodies were assessed by a chemiluminescent method using Architect ci4100, and statistical analysis was performed using R software. Overall, 211 hemodialysis patients aged from 18 to 77 years were enrolled. The mean age was 42.62 years ± 13.6, and the sex ratio M/F was 1.24. The overall seroprevalence of T. gondii was 41.7%, with the highest value being recorded in the region of Kaolack (44.4%). Patients aged over 60 years were more typically infected, at a proportion of 56.0%. Regarding sex, males elicited a higher prevalence (44.4.%) than females did. Patients of an upper socioeconomic status were less affected, and contact with cats was not associated with toxoplasmosis. By education level, the illiterate group was most affected one. Overall, this first study of toxoplasmosis among Senegalese hemodialysis patients indicates high seroprevalence.

Toxoplasma gondii infection induces cell apoptosis via multiple pathways revealed by transcriptome analysis

Toxoplasma gondii is a worldwide parasite that can infect almost all kinds of mammals and cause fatal toxoplasmosis in immunocompromised patients. Apoptosis is one of the principal strategies of host cells to clear pathogens and maintain organismal homeostasis, but the mechanism of cell apoptosis induced by T. gondii remains obscure. To explore the apoptosis influenced by T. gondii, Vero cells infected or uninfected with the parasite were subjected to apoptosis detection and subsequent dual RNA sequencing (RNA-seq). Using high-throughput Illumina sequencing and bioinformatics analysis, we found that pro-apoptosis genes such as DNA damage-inducible transcript 3 (DDIT3), growth arrest and DNA damage-inducible α (GADD45A), caspase-3 (CASP3), and high-temperature requirement protease A2 (HtrA2) were upregulated, and anti-apoptosis genes such as poly(adenosine diphosphate (ADP)-ribose) polymerase family member 3 (PARP3), B-cell lymphoma 2 (Bcl-2), and baculoviral inhibitor of apoptosis protein (IAP) repeat containing 5 (BIRC5) were downregulated. Besides, tumor necrosis factor (TNF) receptor-associated factor 1 (TRAF1), TRAF2, TNF receptor superfamily member 10b (TNFRSF10b), disabled homolog 2 (DAB2)‍-interacting protein (DAB2IP), and inositol 1,4,5-trisphosphate receptor type 3 (ITPR3) were enriched in the upstream of TNF, TNF-related apoptosis-inducing ligand (TRAIL), and endoplasmic reticulum (ER) stress pathways, and TRAIL-receptor 2 (TRAIL-R2) was regarded as an important membrane receptor influenced by T. gondii that had not been previously considered. In conclusion, the T. gondii RH strain could promote and mediate apoptosis through multiple pathways mentioned above in Vero cells. Our findings improve the understanding of the T. gondii infection process through providing new insights into the related cellular apoptosis mechanisms.

Anti-infection roles of miR-155-5p packaged in exosomes secreted by dendritic cells infected with Toxoplasma gondii

BackgroundToxoplasma gondii is a zoonotic intracellular protozoon that is estimated to infect about 30% of the world’s population, resulting in toxoplasmosis in immunocompromised patients and adverse outcomes in cases of primary infection during pregnancy. Exosomes are tubular vesicles secreted by cells, and function in intercellular communication. It has been reported that the exosomes secreted by T. gondii-infected immune cells transmit infection signals to the uninfected cells. However, the mechanism and effect of the exosome transmission are still vague. We therefore investigated the function of the exosomes transmitted from DC2.4 cells infected with the T. gondii RH strain (Tg-DC-Exo) to the uninfected cells, as well as their roles in anti-infection.MethodsWe conducted exosome isolation and identification with ultracentrifugation, transmission electron microscopy (TEM), nanoparticle tracking analysis (NTA), and western blot (WB) analysis. Exosome uptake by recipient cells was identified by PKH67 assay. The signal transmission and the abundance of miR-155-5p were determined using transwell assay and qRT-PCR. For detection of immune responses, cytokine secretion was evaluated. The T. gondii B1 gene was determined to evaluate tachyzoite proliferation.ResultsWe observed that Toxoplasma infection upregulated miR-155-5p expression in DC2.4 cell-secreted exosomes, and those exosomes could be ingested by murine macrophage RAW264.7 cells. Tg-DC-Exo and miR-155-5p stimulated host proinflammatory immune responses including increased production of proinflammatory cytokines IL-6 and TNF-α, and proinflammatory marker-inducible nitric oxide synthase (iNOS). The NF-κB pathway was activated by downregulation of SOCS1, leading to inhibition of T. gondii tachyzoite proliferation in RAW264.7 cells.ConclusionsOur findings provide a novel mechanism for how infected cells transmit infection signals to the uninfected cells through exosome secretion after T. gondii infection, followed by inflammatory responses and anti-infection reactions, which may help us develop a new strategy for toxoplasmosis prevention, especially in immunocompromised patients.Graphical

Multicenter Comparative Assessment of the TIB MolBiol Toxoplasma gondii Detection Kit and Four Laboratory-Developed PCR Assays for Molecular Diagnosis of Toxoplasmosis

Toxoplasmosis can be a life-threatening infection, particularly during pregnancy and in immunocompromised patients. The biological diagnosis of toxoplasmosis is challenging and has been revolutionized by molecular detection methods. This article summarizes the data of a multicenter study involving four centers to assess the performances of a commercial PCR assay as compared with four in-house PCR assays using Toxoplasma gondii standards, 20 external quality control specimens, and 133 clinical samples. This clinical cohort includes well-characterized clinical samples corresponding to different clinical situations: confirmed congenital toxoplasmosis (44 samples), toxoplasmosis in immunocompromised patients (25samples), and chorioretinitis (5 samples). Furthermore, 59 samples from patients without toxoplasmosis were included as negative controls. The analytical sensitivities of the five methods tested were very similar; and the limit of Toxoplasma DNA detection was around 0.01 T. gondii genome per reaction for all the methods. The overall concordance between the commercial PCR and the four in-house PCR assays was 97.7% (130/133). The clinical sensitivity and specificity were >98% and could be increased for the commercial kit when PCR was performed in multiplicate to detect low parasitic loads. In conclusion, thecommercial PCR assay shows suitable performances to diagnose the different clinical forms of toxoplasmosis.

Toxoplasmosis cerebral luego de un trasplante renal

Se reporta el caso de un paciente masculino de 29 años con antecedente de diabetes mellitus tipo 1, con enfermedad renal crónica estadio 5 secundaria a enfermedad renal diabética que requirió de trasplante renal de donante vivo en el año 2018 y en tratamiento inmunosupresor con prednisolona, tacrolimus y micofenolato desde dicho procedimiento, quien ingresó al servicio de urgencias por crisis epiléptica focal con generalización secundaria. El enfoque diagnóstico de toxoplasmosis cerebral en pacientes inmunocomprometidos es un reto clínico debido a la gran variabilidad de signos y síntomas asociados en esta población y a la alta frecuencia de complicaciones, lo cual puede confundir el diagnostico.

Multicentric Evaluation of the Bio-Evolution Toxoplasma gondii Assay for the Detection of Toxoplasma DNA in Immunocompromised Patients.

PCR-based methods are a key tool for the diagnosis of toxoplasmosis in immunocompromised patients. Laboratory-developed protocols lack standardization. This study aimed to assess the performances of a commercial kit for the detection of Toxoplasma DNA in different specimens drawn from immunocompromised patients. This multicentric retrospective study included 227 DNA specimens (157 blood specimens, 22 bronchoalveolar fluid [BALF] specimens, 39 cerebrospinal fluid [CSF] specimens, and 9 miscellaneous specimens) collected between 2010 and 2015 from 126 immunocompromised patients. The specimens were selected based on previous laboratory-developed quantitative PCR (qPCR) analyses targeting either the rep529 element or the B1 gene, and the results were classified as positive, negative, and "negative of interest," where the latter was defined as representing either the last specimen with a negative result before a positive one or the first with a negative result following a positive result(s). All specimens were secondary tested using the Bio-Evolution Toxoplasma DNA assay targeting the T. gondii rep529 element. We found a 95.6% concordance rate for qualitative results obtained with laboratory-developed qPCR techniques and the commercial kit. The rate reached 99.3% in comparisons of rep529-based laboratory-developed PCR methods and the commercial kit. The quantifications obtained with the commercial kit and the rep529 laboratory-developed PCRs were in very good agreement. Sensitivity and specificity of the commercial kit were calculated at 98.8% and 100%, respectively. The Bio-Evolution Toxoplasma DNA assay appears to be a valuable method for the detection of Toxoplasma DNA in blood, BALF, and CSF specimens from immunocompromised patients.

Novel Molecules To Treat Chronic Central Nervous System Toxoplasmosis.

A major challenge in treating toxoplasmosis in immunocompromised patients is lack of therapeutic agents to clear chronic infection and stop the recrudescence of infection after therapy. CDKP1 has emerged as a novel target for treating chronic infections and eliminating latent bradyzoites in the brain. In a mouse model of toxoplasmosis, pyrazolopyrimidine inhibitors of Toxoplasma gondii CDPK1 demonstrated in vitro and in vivo efficacy.

Toxoplasmosis in Immunocompromised Patients: Laboratory Diagnosis

Toxoplasmosis in Immunocompromised Patients: Laboratory Diagnosis

Molecular diagnosis of toxoplasmosis in immunocompromised patients.

Toxoplasmosis in immunocompromised patients is associated with a high mortality rate. Molecular techniques are important tools to diagnose acute disease in immunocompromised patients, but there are various methods with variable efficiency. Some of them have been validated for the diagnosis of congenital toxoplasmosis, but the impact of their use has not been evaluated in immunocompromised patients. Toxoplasmosis is of increasing importance in non-HIV immunocompromised patients. In addition, the picture of disease shows greater severity in South America, both in immunocompetent study participants and in congenitally infected infants. These epidemiological differences could influence the sensitivity of diagnostic methods. This review analyzes recent data on molecular diagnosis and compares them with older ones, in light of progress gained in molecular techniques and of recent epidemiological findings. Most recent studies were conducted in South America and used PCR targeting the B1 gene. PCR on blood could allow diagnosing a significant proportion of patients with ocular toxoplasmosis in Brazil. Quantitative PCR methods with specific probes should be used to improve sensitivity and warrant specificity. Performance of quantitative PCR targeting the repeated 529 bp sequence for the diagnosis of toxoplasmosis in immunocompromised patients needs evaluation in field studies in South America and in western countries.

Pulmonary toxoplasmosis in immunocompromised patients with interstitial pneumonia: a single-centre prospective study assessing PCR-based diagnosis

AimsPulmonary toxoplasmosis has become a very rare parasitic infection since the advent of highly active antiretroviral therapies. It is generally diagnosed by the direct microscopic observation of Toxoplasma gondii tachyzoites...

PATHOGENESI S, DI AGNOSTI C AND MANAGEMENT OF TOXOPLASMOSIS

Toxoplasma gondii is an obligate intracellular parasite of protozoa groups, can infect humans and all warm-blooded animals, are found in almost all locations around the world. Infection generally occurs orally through the consumption of animal products that are not perfectly cooked infected oocyst, parasite containing foods in the form of bradyzoite, contact with cat’s feces containing oocysts or vertical transmission occurring through hematogenous placenta. Toxoplamosis can occur in acute or chronic. It divided into five categories, namely, toxoplasmosis in patients immunocompetent, toxoplasmosis in pregnancy, congenital toxoplasmosis, toxoplasmosis in immunocompromised patients and ocular toxoplasmosis. In each category of clinical manifestations of toxoplasmosis are often non-specific. Methods of diagnosis and interpretation are often different for each category. Toxoplasmosis can be diagnosed through a series of tests such as serology, PCR, histology parasites and parasite isolation. Treatment management of this disease requires a long time. Therapy depends on the category of infections as well as individual therapeutic response. The combination of pyrimethamine with sulfadiazine is the drug choice for toxoplasmosis.

Eukaryotic Plasmids with Toxoplasma gondii Dense Granule Antigen(GRA 5) and Microneme 3 (MIC3) Genes as a Cocktail DNA Vaccine and Evaluation of Immune Responses in BALB/C Mice

Toxoplasma gondii is an obligate intracellular protozoan that causes toxoplasmosis in human and animal. This parasite is worldwide spread and about one third of people are seropositive. Toxoplasmosis in immuno compromised patients causes serious symptoms. Toxoplasma gondii has a lot of various immunogenic antigens. Excreted/secreted antigens could stimulate of the cell mediated immune response and hence it appears to be a good candidate for vaccine in toxoplasmosis. In this study Microneme3 (MIC3) and GRA5 of Toxoplasma gondii are used as DNA vaccine. The results indicated that survival rate of mice that immunized by recombinant plasmid have significant differences with control groups. IgG and IgG2a assay approved significant different between case and control groups (P<0.05). Cytokine assay indicated high level of IFN-γ and low level of IL4 for immunized groups.These results indicated DNA vaccine encoded MIC3 and GRA5 genes of Toxoplasma gondii capable to induced partially protection against toxoplasmosis.

Toxoplasmosis in immunocompromised patients in Iran: a systematic review and meta-analysis.

Although toxoplasmosis in immunocompetent individuals is generally asymptomatic, in immunocompromised patients (HIV/AIDS, cancer, and transplant patients), it can lead to serious pathological effects. This study included a systematic review and meta-analysis to comprehensively assess the seroprevalence rate of Toxoplasma infection in immunocompromised patients in Iran. Electronic English and Persian databases (PubMed, Google Scholar, ScienceDirect, Scopus, Magiran, Scientific Information Database [SID], IranMedex, and IranDoc), parasitology congresses, and projects and theses of Iranian medical universities, were systematically searched from 1997 to 2013 (published or unpublished data). In this paper, several studies that used serological methods for diagnosis of toxoplasmosis were selected. Analysis of seroprevalence estimates was pooled using a random-effects meta-analysis. Twenty-two studies, comprising 2,805 individuals, were included in the meta-analysis. Overall seroprevalence rate of Toxoplasma infection in Iranian immunocompromised patients was 50.01% (95% confidence interval, 43.85 to 56.17); however, there was significant heterogeneity among study groups. The results showed that seroprevalence rate of toxoplasmosis among transplant recipients, HIV/AIDS, and cancer patients in Iran was 55.1%, 50.05%, and 45.06%, respectively. In addition, IgM seroprevalence rate was estimated to be 4.85% (95% confidence interval, 2.22 to 8.41). This systematic review and meta-analysis identified a high seroprevalence rate of Toxoplasma infection among immunocompromised patients (50%). Consideration of management, design and provision of appropriate control measures of toxoplasmosis is highly recommended.

Role of advanced magnetic resonance imaging techniques in diagnosis of cerebral toxoplasmosis in immunocompromised patients: A case report

Cerebral toxoplasmosis commonly affects patients with advanced HIV infection. Toxoplasmosis can be severe and debilitating in patients with Central Nervous System (CNS) involvement and the condition may be fatal in patients if not suspected and treated early and adequately. Hence, imaging plays an important role in diagnosis and following during treatment in cases of suspected toxoplasmosis. We report a case of a 51-years-old man who was a known sero-positive since 2 years and presented with altered sensorium. Magnetic Resonance Imaging (MRI) scan of the brain showed multiple heterogeneously enhancing lesions in bilateral cerebral as well as cerebellar hemispheres and some of them showed eccentric target sign. MR spectroscopy showed features of reduced NAA, mildly increased choline, and lipid lactate peak. MR perfusion study showed reduced perfusion favoring diagnosis of cerebellar toxoplasmosis. Patient was started on a combination of pyrimethamine plus sulfadiazine for toxoplasmosis. Follow up MRI after 20 days and 45 days from start of treatment showed significant resolution of the lesions supporting our radiological diagnosis.

MRI findings in toxoplasmosis cerebralis

We present the case of a 25 years-old HIV infected patient with low CD4 count who presented seizures and receptive language disturbances. The MRI findings were highly suggestive for cerebral Toxoplasmosis. An empirical treatment for Toxoplasma gondii was started, with favorable outcome. We discuss the MRI findings in cerebral toxoplasmosis in immunocompromised patients.

Genotype of 88Toxoplasma gondiiIsolates Associated with Toxoplasmosis in Immunocompromised Patients and Correlation with Clinical Findings

We report the genotyping analysis of Toxoplasma gondii isolates in samples collected from 88 immunocompromised patients, along with clinical and epidemiological data. Most of these samples were collected in France during the current decade by the Toxoplasma Biological Resource Center. Lack of specific anti-Toxoplasma treatment, pulmonary toxoplasmosis, and involvement of multiple organs were the 3 main risk factors associated with death for this patient group. Genotyping results with 6 microsatellite markers showed that type II isolates were predominant among patients who acquired toxoplasmic infection in Europe. Non-type II isolates included 13 different genotypes and were mainly collected from patients who acquired toxoplasmosis outside Europe. Type III was the second most common genotype recovered from patients, whereas type I was rare in our population. Three nonarchetypal genotypes were repeatedly recovered from different patients who acquired the infection in sub-Saharan Africa (genotypes Africa 1 and Africa 2) and in the French West Indies (genotype Caribbean 1). The distribution of genotypes (type II vs. non-type II) was not significantly different when patients were stratified by underlying cause of immunosuppression, site of infection, or outcome. We conclude that in immunocompromised patients, host factors are much more involved than parasite factors in patients' resistance or susceptibility to toxoplasmosis.