Assessment of tissue levels of miR-146a and proinflammatory cytokines in experimental cerebral toxoplasmosis following atovaquone and clindamycin treatment: An in vivo study

BACKGROUND

Despite recent advances for treating cerebral toxoplasmosis (CT), monitoring the parasite burden and treatment response is still challenging. miRNAs are small non-coding RNAs with regulatory functions that can be used in diagnosis and treatment monitoring. We investigated the changes in miR-146a, BAG-1 gene, IL-6, and IL-10 tissue levels in the brain of BALB/c mice with chronic CT caused by the PRU strain of T. gondii following anti-parasitic and antibiotic treatment.

METHOD

Fifty-three 6-to 8-week-old BALB/c mice were infected using intraperitoneal inoculation of cerebral cysts of T. gondii PRU strain and then divided into five groups as follows: group 1 included mice treated with 100 mg/kg/d Atovaquone (AT), group 2 included mice treated with 400 mg/kg/d clindamycin (CL), group 3 included mice treated with combination therapy (AT + CL), group 4 included infected untreated mice as a positive control (PC), and; group 5 included uninfected untreated mice as negative control (NC). After the completion of the treatment course, tissue level of mir-146a, miR-155, BAG-1 gene, IL-6, and IL-10 was investigated with real-time polymerase chain reaction. The IL-6/IL-10 ratio was calculated as an indicator of immune response. Moreover, brain cyst numbers were counted on autopsy samples.

RESULTS

miR-146a, IL-6, IL-10, and BAG-1 genes were expressed in PC, but not in the NC group; miR-146a, IL-6, IL-10, and BAG-1 gene expression were significantly lower in AT, CL, and AT + CL compared with PC. MiR-146a and BAG-1 levels in AT and CL were not different statistically, however, they both had lower levels compared to AT + CL (P < 0.01). There was no difference in the expression of IL-6 and IL-10 between treatment groups. BAG-1 expression was significantly lower in AT, than in CL and AT + CL (P < 0.0089 and < 0.002, respectively). The PC group showed a higher ratio of IL-6/IL-10, although this increase was not statistically significant. It is noteworthy that the treatment with AT reduced this ratio; in the inter-group comparison, this ratio showed a decrease in the AT and AT + CL compared to the PC. The number of brain tissue cysts was significantly lower in AT, CL, and AT + CL, than in PC (p < 0.0001). AT had significantly lower brain cysts than CL and AT + CL (P < 0.0001).

CONCLUSION

It seems that the factors studied in the current research (microRNA and cytokines) are a suitable index for evaluating the response to antiparasitic and antibiotic treatment. However, more studies should be conducted in the future to confirm our findings.

Iron-overload-induced ferroptosis in mouse cerebral toxoplasmosis promotes brain injury and could be inhibited by Deferiprone

Iron is a trace metal element that is essential for the survival of cells and parasites. The role of iron in cerebral toxoplasmosis (CT) is still unclear. Deferiprone (DFP) is the orally active iron chelator that binds iron in a molar ratio of 3:1 (ligand:iron) and promotes urinary iron excretion to remove excess iron from the body. The aims of this experiment were to observe the alterations in iron in brains with Toxoplasma gondii (T. gondii) acute infections and to investigate the mechanism of ferroptosis in CT using DFP. We established a cerebral toxoplasmosis model in vivo using TgCtwh3, the dominant strains of which are prevalent in China, and treated the mice with DFP at a dose of 75 mg/kg/d. Meanwhile, we treated the HT-22 cells with 100 μM DFP for half an hour and then infected cells with TgCtwh3 in vitro. A qRT-PCR assay of TgSAG1 levels showed a response to the T. gondii burden. We used inductively coupled plasma mass spectrometry, an iron ion assay kit, Western blot analysis, glutathione and glutathione disulfide assay kits, a malonaldehyde assay kit, and immunofluorescence to detect the ferroptosis-related indexes in the mouse hippocampus and HT-22 cells. The inflammatory factors interferon-γ, tumor necrosis factor-α, transforming growth factor-β, and arginase 1 in the hippocampus and cells were detected using the Western blot assay. Hematoxylin and eosin staining, electron microscopy, and the Morris water maze experiment were used to evaluate the brain injuries of the mice. The results showed that TgCtwh3 infection is followed by the activation of ferroptosis-related signaling pathways and hippocampal pathological damage in mice. The use of DFP led to ferroptosis resistance and attenuated pathological changes, inflammatory reactions and T. gondii burden of the mice, prolonging their survival time. The HT-22 cells with TgCtwh3 activated the ferroptosis pathway and was inhibit by DFP in vitro. In TgCtwh3-infected cells, inflammatory response and mitochondrial damage were severe, but these effects could be reduced by DFP. Our study elucidates the mechanism by which T. gondii interferes with the host's iron metabolism and activates ferroptosis, complementing the pathogenic mechanism of CT and further demonstrating the potential value of DFP for the treatment of CT.

[Cerebral toxoplasmosis developed after unrelated bone marrow transplantation for acute myeloid leukemia]

A 16-year-old boy received an unrelated bone marrow transplant while in second remission of acute myeloid leukemia. He suffered from severe oral mucosal complications and had difficulty taking oral drugs such as sulfamethoxazole/trimethoprim (ST). Engraftment was obtained on transplant day 35, and blurred vision and headache appeared around transplant day 60. Funduscopy revealed retinal hemorrhage and macular edema, and an MRI scan of the head revealed a nodular lesion in the left putamen. Toxoplasma gondii was detected by CSF PCR, and cerebral toxoplasmosis was diagnosed. Following therapy with ST and clindamycin, the patient was administered pyrimethamine, sulfadiazine, and leucovorin. Symptoms improved promptly, and CSF PCR was negative 45 days after the start of treatment. Since the prevalence of toxoplasma antibodies increases with age, it is crucial to avoid toxoplasma reactivation by ST after hematopoietic cell transplantation in postpubescent patients.

Synergistic sulfonamides plus clindamycin as an alternative therapeutic regimen for HIV-associated Toxoplasma encephalitis: a randomized controlled trial

BACKGROUND

The preferred therapeutic regimen for Toxoplasma encephalitis (TE) is a combination of pyrimethamine and sulfadiazine, and trimethoprim-sulfamethoxazole (TMP-SMX) plus azithromycin is the widespread alternative therapeutic regimen. The synergistic sulfonamides tablet contains TMP, sulfadiazine, and SMX and hypothetically could be used for TE treatment. This study aimed to compare the efficacy and safety of synergistic sulfonamides plus clindamycin (regimen B) with TMP-SMX plus azithromycin (regimen A) for the treatment of human immunodeficiency virus (HIV) associated TE.

METHODS

This was an open-labeled, multi-center randomized controlled trial recruited from 11 centers. Each recruited patient was randomly assigned to receive regimen A or regimen B for at least 6 weeks. The overall response was evaluated by assessment of the clinical response of TE-associated clinical features and the radiological response of TE-associated radiological findings. The overall response rate, clinical response rate, radiological response rate, and adverse events were assessed at 2, 6, and 12 weeks. Death events were compared between the two regimens at 6, 12, and 24 weeks.

RESULTS

A total of 91 acquired immunodeficiency syndrome (AIDS)/TE patients were included in the final analysis (44 in regimen A vs . 47 in regimen B). The overall response rate, which refers to the combined clinical and radiological response, was 18.2% (8/44) for regimen A and 21.3% (10/47) for regimen B at week 6. The results of clinical response showed that, in comparison with regimen A, regimen B may perform better with regards to its effect on the relief of clinical manifestations (50.0% [22/44] vs . 70.2% [33/47], P = 0.049). However, no significant differences in radiological response, mortality events, and adverse events were found between the two regimens at week 6.

CONCLUSIONS

Synergistic sulfonamides plus clindamycin, as a novel treatment regimen, showed no significantly different efficacy and comparable safety in comparison with the TMP-SMX plus azithromycin regimen. In addition, the regimen containing synergistic sulfonamides may exhibit advantages in terms of clinical symptom alleviation.

TRIAL REGISTRATION

ChiCTR.org.cn, ChiCTR1900021195.

Brief Report: Financial Burden of Toxoplasmosis Encephalitis Treatment at a Safety Net Hospital

BACKGROUND

Although the price increase of pyrimethamine in 2015 received heavy media coverage, there are little data regarding specific implications to hospitals and the total costs of treating inpatients with toxoplasmosis encephalitis (TE).

METHODS

Using average drug wholesale costs, we estimated the inpatient drug costs of TE drugs 3 years prepyrimethamine and postpyrimethamine price increase in August 2015. The drug regimens and total doses were determined through retrospective chart review of patients living with HIV who received treatment for TE while inpatient during this period.

RESULTS

The 3-year pre-increase TE drug costs for 66 admissions were estimated at $50,310 compared with a total drug cost of $1,026,006 for 61 admissions postincrease. Pyrimethamine made up 98% of the drug costs postincrease, compared with 57% pre-increase. Pyrimethamine-based regimens were the most frequently used throughout the study period.

CONCLUSIONS

The price increase of pyrimethamine in 2015 led to a substantial and unnecessary financial burden to hospitals. This required health care systems to shift valuable resources to continue to provide medications to a vulnerable patient population. There has been more focus on providing high-value care in recent years. Our study highlights the need for further examination of pharmaceutical companies' arbitrary determination of medication costs and how they contribute to patient care.

Four Chemotherapeutic Compounds That Limit Blood-Brain-Barrier Invasion by Toxoplasma gondii

Background: Toxoplasma gondii, an intracellular protozoan parasite, exists in the host brain as cysts, which can result in Toxoplasmic Encephalitis (TE) and neurological diseases. However, few studies have been conducted on TE, particularly on how to prevent it. Previous proteomics studies have showed that the expression of C3 in rat brains was up-regulated after T. gondii infection. Methods: In this study, we used T. gondii to infect mice and bEnd 3 cells to confirm the relation between T. gondii and the expression of C3. BEnd3 cells membrane proteins which directly interacted with C3a were screened by pull down. Finally, animal behavior experiments were conducted to compare the differences in the inhibitory ability of TE by four chemotherapeutic compounds (SB290157, CVF, NSC23766, and Anxa1). Results: All chemotherapeutic compounds in this study can inhibit TE and cognitive behavior in the host. However, Anxa 1 is the most suitable material to inhibit mice TE. Conclusion: T. gondii infection promotes TE by promoting host C3 production. Anxa1 was selected as the most appropriate material to prevent TE among four chemotherapeutic compounds closely related to C3.

Delayed Cerebral Toxoplasmosis in a Kidney Transplant Patient: a Case Report

Cerebral toxoplasmosis is often life-threatening in an immunocompromised patient due to delayed diagnosis and treatment. Several differential diagnoses could be possible only with preoperative brain images of cerebral toxoplasmosis which show multiple rim-enhancing lesions. Due to the rarity of cerebral toxoplasmosis cases in Korea, the diagnosis and treatment are often delayed. This paper concerns a male patient whose cerebral toxoplasmosis was activated 21 years post kidney transplantation. Brain open biopsy was decided to make an exact diagnosis. Cerebral toxoplasmosis was confirmed by immunohistochemistry and PCR analyses of the tissue samples. Although cerebral toxoplasmosis was under control with medication, the patient did not recover clinically and died due to sepsis and recurrent gastrointestinal bleeding.

Determination of parasitic burden in the brain tissue of infected mice in acute toxoplasmosis after treatment by fluconazole combined with sulfadiazine and pyrimethamine

BACKGROUND/AIMS

One of the opportunistic pathogens which cause serious problems in the human immune system is Toxoplasma gondii, with toxoplasma encephalitis (TE) seen in patients affected by it. The treatment of these patients is limited, and if not treated on time, death will be possible.

METHODS

In this study, the effects of the treatment with different doses of fluconazole (FLZ) in combination with the current treatment of acute toxoplasmosis on reducing the mortality rate and the parasitic load in the murine model in vivo were studied. The mice were treated with different doses of fluconazole alone, sulfadiazine, and pyrimethamine plus fluconazole. A day after the end of the treatment and 1 day before death, the mice's brains were collected, and after DNA extraction and molecular tests, the parasite burden was detected.

RESULTS

This study showed that a 10-day treatment with 20 mg/kg of fluconazole combined with sulfadiazine and pyrimethamine 1.40 mg/kg per day affected acute toxoplasmosis and reduced the parasitic load significantly in brain tissues and also increased the survival rate of all mice in this group until the last day of the study, in contrast to other treatment groups. These results also indicate the positive effects of combined therapy on Toxoplasma gondii and the prevention of relapse.

CONCLUSIONS

Reducing the parasitic burden and increasing the survival rate were more effective against acute toxoplasmosis in the combined treatment of different doses of fluconazole with current treatments than current treatments without fluconazole. In other words, combination therapy with fluconazole plus pyrimethamine reduced the parasitic burden in the brain significantly, so it could be a replacement therapy in patients with intolerance sulfadiazine.

Diffuse encephalitic toxoplasmosis in HIV

This case demonstrates an atypical radiological presentation of cerebral toxoplasmosis in a 62-year-old HIV-positive patient. The diagnosis is discussed alongside MRI imaging, laboratory results and treatment. Central nervous system toxoplasmosis is typically associated with ring enhancing lesions on neuroimaging with contrast, but the radiology for this patient shows diffuse white matter changes and ependymal enhancement, which would normally suggest an alternative diagnosis.

Hypericum perforatum extract and hyperforin inhibit the growth of neurotropic parasite Toxoplasma gondii and infection-induced inflammatory responses of glial cells in vitro

ETHNOPHARMACOLOGICAL RELEVANCE

Hypericum perforatum L. has been widely used as a natural antidepressant. However, it is unknown whether it is effective in treating infection-induced neuropsychiatric disorders.

AIM OF THE STUDY

In order to evaluate the effectiveness of H. perforatum against infection with neurotropic parasite Toxoplasma gondii, which has been linked to neuropsychiatric disorders, this study investigated the anti-Toxoplasma activity using in vitro models.

MATERIALS AND METHODS

Dried alcoholic extracts were prepared from three Hypericum species: H. perforatum, H. erectum, and H. ascyron. H. perforatum extract was further separated by solvent-partitioning. Hyperforin and hypericin levels in the extracts and fractions were analyzed by high resolution LC-MS. Anti-Toxoplasma activities were tested in vitro, using cell lines (Vero and Raw264), murine primary mixed glia, and primary neuron-glia. Toxoplasma proliferation and stage conversion were analyzed by qPCR. Infection-induced damages to the host cells were analyzed by Sulforhodamine B cytotoxicity assay (Vero) and immunofluorescent microscopy (neurons). Infection-induced inflammatory responses in glial cells were analysed by qPCR and immunofluorescent microscopy.

RESULTS

Hyperforin was identified only in H. perforatum among the three tested species, whereas hypericin was present in H. perforatum and H. erectum. H. perforatum extract and hyperforin-enriched fraction, as well as hyperforin, exhibited significant anti-Toxoplasma property as well as inhibitory activity against infection-induced inflammatory responses in glial cells. In addition, H. perforatum-derived hyperforin-enriched fraction restored neuro-supportive environment in mixed neuron-glia culture.

CONCLUSIONS

H. perforatum and its major constituent hyperforin are promising anti-Toxoplasma agents that could potentially protect neurons and glial cells against infection-induced damages. Further study is warranted to establish in vivo efficacy.

A study for precision diagnosing and treatment strategies in difficult-to-treat AIDS cases and HIV-infected patients with highly fatal or highly disabling opportunistic infections: Study protocol for antiretroviral therapy timing in AIDS patients with toxoplasma encephalitis

BACKGROUND

Toxoplasma encephalitis (TE) is one of the main opportunistic infections in acquired immunodeficiency syndrome (AIDS) patients, and represents a social burden due to its high prevalence and morbidity. Concomitant antiretroviral therapy (ART), together with effective anti- toxoplasma combination therapy, is an effective strategy to treat AIDS-associated TE (AIDS/TE) patients. However, the timing for the initiation of ART after diagnosis of TE remains controversial. We therefore designed the present study to determine the optimal timing for ART initiation in AIDS/TE patients.

METHODS/DESIGN

This trial is a 17-center, randomized, prospective clinical study with 2 parallel arms. A total of 200 participants will be randomized at a 1:1 ratio into the 2 arms: the early ART initiation (≤14 days after TE diagnosis) arm and the deferred ART (>14 days after TE diagnosis) arm. The primary outcome will be the difference of mortality between the 2 arms at 48 weeks. The secondary outcomes will be the differences between the 2 arms in the changes of CD4+ counts from baseline to week 48, the rate of virologic suppression (HIV ribonucleic acid <50 copies/mL) from baseline to week 48, the incidence of TE-associated immune reconstitution inflammatory syndrome during the study period, and the incidence of adverse effects during the study period.

DISCUSSION

This present trial aims to evaluate the optimal timing for ART initiation in AIDS/TE patients, and will provide strong evidence for AIDS/TE treatment should it be successful.

TRIAL REGISTRATION

This trial was registered as one of the 12 trials under the name of a general project at the chictr.gov (http://www.chictr.org.cn/showproj.aspx?proj=35362) on February 1, 2019, and the registration number of the general project is ChiCTR1900021195.

A study for precision diagnosing and treatment strategies in difficult-to-treat AIDS cases and HIV-infected patients with highly fatal or highly disabling opportunistic infections

BACKGROUND

An increased frequency of toxoplasma encephalitis, caused by Toxoplasma gondii, has been reported in AIDS patients, especially in those with CD4+ T cell counts <100 cells/μL. Several guidelines recommend the combination of pyrimethamine, sulfadiazine, and leucovorin as the preferred regimen for AIDS-associated toxoplasma encephalitis. However, it is not commonly used in China due to limited access to pyrimethamine and sulfadiazine. The synergistic sulfonamides tablet formulation is a combination of trimethoprim (TMP), sulfadiazine and sulfamethoxazole (SMX), and is readily available in China. Considering its constituent components, we hypothesize that this drug may be used as a substitute for sulfadiazine and TMP-SMX. We have therefore designed the present trial, and propose to investigate the efficacy and safety of synergistic sulfonamides combined with clindamycin for the treatment of toxoplasma encephalitis.

METHODS/DESIGN

This study will be an open-labeled, multi-center, prospective, randomized, and controlled trial. A total of 200 patients will be randomized into TMP-SMX plus azithromycin group, and synergistic sulfonamides plus clindamycin group at a ratio of 1:1. All participants will be invited to participate in a 48-week follow-up schedule once enrolled. The primary outcomes will be clinical response rate and all-cause mortality at 12 weeks. The secondary outcomes will be clinical response rate and all-cause mortality at 48 weeks, and adverse events at each visit during the follow-up period.

DISCUSSION

We hope that the results of this study will be able to provide reliable evidence for the efficacy and safety of synergistic sulfonamides for its use in AIDS patients with toxoplasma encephalitis.

TRIAL REGISTRATION

This study was registered as one of 12 clinical trials under the name of a general project at chictr.gov on February 1, 2019, and the registration number of the general project is ChiCTR1900021195. This study is still recruiting now, and the first patient was screened on March 22, 2019.

Combination of Clindamycin and Azithromycin as Alternative Treatment for Toxoplasma gondii Encephalitis

Current standard therapies for toxoplasmic encephalitis often cause severe adverse events. A 57-year-old HIV-positive man in Japan who had toxoplasmic encephalitis but was intolerant to trimethoprim/sulfamethoxazole, pyrimethamine, sulfadiazine, and atovaquone was successfully treated with the combination of clindamycin and azithromycin. This drug combination can be an alternative treatment for this condition.

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

Cerebral toxoplasmosis is the most common cause of expansive brain lesions in people living with HIV/AIDS (PLWHA) and continues to cause high morbidity and mortality. The most frequent characteristics are focal subacute neurological deficits and ring-enhancing brain lesions in the basal ganglia, but the spectrum of clinical and neuroradiological manifestations is broad. Early initiation of antitoxoplasma therapy is an important feature of the diagnostic approach of expansive brain lesions in PLWHA. Pyrimethamine-based regimens and trimethoprim-sulfamethoxazole (TMP-SMX) seem to present similar efficacy, but TMP-SMX shows potential practical advantages. The immune reconstitution inflammatory syndrome is uncommon in cerebral toxoplasmosis, and we now have more effective, safe, and friendly combined antiretroviral therapy (cART) options. As a consequence of these 2 variables, the initiation of cART can be performed within 2 weeks after initiation of antitoxoplasma therapy. Herein, we will review historical and current concepts of epidemiology, diagnosis, and treatment of HIV-related cerebral toxoplasmosis.

Cerebral Toxoplasmosis Diagnosed by Nested-polymerase Chain Reaction in a Patient with Rheumatoid Arthritis

A 65-year-old woman with rheumatoid arthritis (RA) visited our hospital because of right facial sensory hypoesthesia. Cerebral toxoplasmosis was suspected on brain magnetic resonance imaging. We discontinued methotrexate for RA and started a sulfamethoxazole/trimethoprim (ST) mixture. Although ST treatment was interrupted because of adverse reactions, her prognosis was favorable. The Toxoplasma 18S rDNA gene was detected by nested-polymerase chain reaction (PCR) from blood and cerebrospinal fluid. Detecting the Toxoplasma 18S rDNA gene by nested-PCR is useful for the diagnosis and safer than a brain biopsy. In addition, the discontinuation of immunosuppressants may be recommended in patients compromised by those immunosuppressants.

Anti-N-methyl-D-aspartate receptor encephalitis associated with acute Toxoplasma gondii infection: A case report

RATIONALE

Anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis has been recognized as the most frequent autoimmune encephalitis in children. Several infectious agents have been implicated in anti-NMDA encephalitis.

PATIENT CONCERNS

A previously healthy immunocompetent 9-year-old girl first presented with seizures, headaches and vomiting. Cerebrospinal fluid and brain magnetic resonance imaging were normal. After one week onset, the patient gradually developed unexplained personality and behavior changes, accompanied by fever and seizures again. Repeated CSF analysis revealed a slightly lymphocytic predominant pleocytosis and positive anti-NMDAR antibody. A variety of pathogenic examinations were negative, except for positive toxoplasma IgM and IgG.

DIAGNOSES

The patient was diagnoses for anti-NMDA encephalitis associated with acute acquired toxoplasma gondii infection.

INTERVENTIONS

The patient received 10 days azithromycin for treatment of acquired toxoplasma infection. The parents refuse immunotherapy because substantial recovery from clinical symptoms.

OUTCOMES

The patient was substantially recovered with residual mild agitation after therapy for acquired toxoplasma gondii infection. Two months later, the patient was completely devoid of symptoms, and the levels of serum IgM and IgG of toxoplasma gondii were decreased.

LESSONS

Acquired toxoplasma gondii infection may trigger anti-NMDAR encephalitis in children, which has not been reported previously. Clinicians should assess the possibility of toxoplasma gondii infection when evaluating a patient with anti-NMDA encephalitis.

Relationship between toxoplasmosis and schizophrenia: A review

A growing body of evidence suggests a correlation between schizophrenia and exposure to infectious agents. The majority of studied cases concerns the infection caused by T. gondii, an obligatory intracellular parasite that infects about 1/3 of the entire human population, according to the available data. The acute stage of the disease, predominantly short-lived and transient, transforms into the latent and chronic phase in which the parasite localizes within tissue cysts, mainly in the central nervous system. The chronic toxoplasmosis, primarily regarded as benign and asymptomatic, might be responsible, in light of current scientific evidence, for a vast array of neuropsychiatric symptoms. Numerous epidemiological case-control studies show a higher prevalence of T. gondii infestation in individuals with various psychiatric and behavior disorders, including schizophrenia. This paper tends to review the relevant studies that demonstrate links between schizophrenia and T. gondii infestation, of which the latter may be acquired in different developmental phases. Apart from epidemiological correlation studies, some papers on other associations were also presented, describing putative patophysiological mechanisms that might be at least partly responsible for chronic infection-induced neuromediator disturbances, together with morphological and functional alterations, e.g., low-grade neuroinflammation, which are likely to induce psychopathological symptoms. Toxoplasmosis is only one of the putative infectious agents that derange correct brain growth and differentiation, alongside genetic and environmental factors. All of them may lead eventually to schizophrenia. A better knowledge of infection mechanisms and its influence on neurobiochemical and neuropathological pathways may enable more efficient therapy and the prevention of this devastating disease.

Contribution of arterial spin-labelling MRI in a case with immune reconstitution inflammatory syndrome

Central nervous system immune reconstitution inflammatory syndrome (CNS-IRIS), which occurs most often in HIV-infected patients, is an exacerbation of inflammatory reactions related to opportunistic infections as well as primary CNS malignancies both of which mostly occur in HIV-infected patients. However, differential diagnoses are challenging both clinically and radiologically. We describe a patient with CNS-IRIS due to toxoplasmosis whose ¹¹C-methionine uptake suggested lymphoma but whose arterial spin-labelling MRI led to the correct diagnosis.

Life-Threatening Complications of HIV Infection

Few modern diseases have experienced as rapid and dramatic change in prognosis and treatment as HIV infection. The introduction of active antiretroviral therapy (ART) and effective prophylaxis of opportunistic infections ushered in a new era in the treatment of HIV infection and changed dramatically the natural history of this disease. The rates of admission to the intensive care unit (ICU) and intensive care mortality in patients with HIV infection have shifted repeatedly during the AIDS epidemic, influenced by attitudes of patients and providers toward utility of care. In the ART era, patients with HIV infection admitted to the ICU fall into 3 general categories: those with AIDS-related opportunistic infections, those who are experiencing complications related to ART, and those with medical problems unrelated to HIV infection. In this article, the authors provide a review of the most common life-threatening complications in patients with HIV infection.

Toxoplasmic Encephalitis with Untreated Hairy Cell Leukemia Variant

Toxoplasmic encephalitis is a rare infectious complication in patients with hematological malignancy except for allogeneic hematopoietic stem cell transplantation (HSCT). We herein report a case of possible toxoplasmic encephalitis with untreated hairy cell leukemia variant. Magnetic resonance imaging showed multiple nodules with surrounding edema in the entire cerebrum. A polymerase chain reaction analysis for Toxoplasma gondii was negative. Her signs and symptoms fully recovered by empirical therapy with sulfadiazine and pyrimethamine. Toxoplasmic encephalitis may occur in patients who undergo non-allogeneic HSCT for hematological malignancies, even in those who have not been treated.

Multiple intracerebral lesions in a young male

BACKGROUND

As the incidence of HIV infection has increased its neurological complications are being encountered in our clinical practice. Toxoplasmosis is a common cerebral opportunistic infection seen in HIV-infected patients, even though the incidence has declined with the use of antiretroviral therapy. Establishing a definitive diagnosis of cerebral toxoplasmosis is difficult in resource limited settings.

CLINICAL CASE

A 20 year old gentleman was referred to our institute as a case of stroke. Magnetic resonance imaging (MRI) of his brain showed multiple ill-defined and nodular enhancing lesions in bilateral supratentorial and infratentorial neuroparenchyma. Test for HIV-1 was reactive. Toxoplasma serology revealed raised IgG antibody levels. Based on the MRI features and positive toxoplasma serology a diagnosis of cerebral toxoplasmosis was made. He was treated with trimethoprim/sulfamethoxazole and pyrimethamine/ Sulfadoxine for 3 weeks. After 2 weeks of treatment, repeat MRI of brain was done which showed significant resolution of the lesions.

CONCLUSION

We are presenting this case to highlight the fact that cerebral toxoplasmosis should be considered in the differential diagnosis of multiple neuroparenchymal lesions in young individuals who present with neurological deficits.

[Cerebral toxoplasmosis after umbilical cord blood transplantation diagnosed by the detection of anti-toxoplasma specific IgM antibody in cerebrospinal fluid]

Cerebral toxoplasmosis is a rare, potentially fatal, complication of hematopoietic cell transplantation. Early definitive diagnosis is very difficult and it may be associated with a poor prognosis. Herein, we describe a 60-year-old woman who developed cerebral toxoplasmosis after cord blood transplantation for myelodysplastic syndrome. During treatment with tacrolimus and methylprednisolone for relapsed grade 2 acute gut GVHD, fever and disturbance of consciousness occurred on day 210. Brain MRI showed multiple ring-enhancing nodular lesions in the thalamus, basal ganglia, brainstem, and subcortical white matter. Cerebrospinal fluid (CSF) assessment revealed elevations of both anti-to-xoplasma IgM and IgG, which were also elevated in serum, but no evidence of other infections or malignancies. Notably, the IgM level was higher in the CSF than in serum. Thus, cerebral toxoplasmosis was diagnosed. Soon after administration of oral sulfamethoxazole/trimethoprim and intravenous clindamycin in combination with short-term dexamethasone for the cerebral edema, her symptoms and signs began to improve. On day 229, both IgM and IgG titers in CSF had clearly decreased but remained essentially constant in serum. She was discharged without clinically significant neurological disorders. This case suggests that CSF specific anti-toxoplasma IgM titers might be useful for early diagnosis of cerebral toxoplasmosis after transplantation.

CNS toxoplasmosis presenting with obstructive hydrocephalus in patients of retroviral disease--a case series

CNS toxoplasmosis presenting as hydrocephalus is a very rare entity. We present three cases of HIV positive patients whose brain imaging revealed hydrocephalus and who improved with anti toxoplasma medication along with intravenous steroids and did not require any CSF shunting procedures. The mechanism of hydrocephalus in CNS toxoplasmosis is usually due to compression of CSF outflow pathway by ring enhancing lesions but even in their absence hydrocephalus can be rarely seen due to ventriculitis. Hence in HIV positive patients with unexplained hydrocephalus CNS toxoplasmosis should be considered and such patients if started on treatment early have a good prognosis without requiring neurosurgical intervention.

[Cerebral toxoplasmosis during AIDS in the infectious diseases department of Point-G Teaching Hospital, Bamako, Mali]

Cerebral toxoplasmosis is common opportunistic infections of central nervous system in AIDS. It occurs most often in case of severe immunosuppression. The aim of this study is to investigate the general characteristics of cerebral toxoplasmosis during HIV infection and AIDS in hospital area in Bamako. It is a retrospective study of 5 years (form January 2001 to December 2005), conducted in the infectious diseases department of Point G Teaching Hospital of Bamako. It concerned all patients infected with HIV, hospitalized for cerebral toxoplasmosis. The diagnosis of cerebral toxoplasmosis was based on clinical, C T and therapeutic arguments. A total of 745 patients investigated, 26 met cerebral toxoplasmosis diagnostic criteria (14 men and 12 women). The rate of cerebral toxoplasmosis in the study population was 3.5%. The average age was 38.1 years (18-58 years). Focused neurological deficit (73.07%), intracranial hypertension signs (69.20%), meningeal syndrome (15.40%), seizures (57.69%) and consciousness disorders (30.80%) were the clinical characteristics. Hypodensity with or without peripheral enhancement images (93.75%) were found on CT. The average rate of CD4 T cells was 98.7cells/mm3 (5-473 cells/mm3). Oropharyngeal candidiasis in 61.53% of cases, intestinal cryptosporidiosis (11.53%), herpes zoster (3.84%) and Pott's disease (3.84%) were the opportunistic infections associated. Cotrimoxazole was used in 88.46% of patients and 3 patients (11.54%) received the standard treatment (Sulfadiazine-Pyrimethamine). Antitoxoplasmic treatment led to a clinical improvement in 84.61% and 4 deaths (15.39%). were recorded. The technical platform for etiological diagnosis of toxoplasmosis is not available at the Point-G Teaching Hospital, so in case of encephalitis signs in a HIV positive patient, CT should be urgently perform and a treatment trial must begin without delay.

Cerebral toxoplasmosis in systemic lupus erythematosus following intravenous methylprednisolone

Cerebral toxoplasmosis is a rare complication of systemic lupus erythematosus (SLE). An 18 year old male student, newly diagnosed to have SLE, developed neurological symptoms two days after completing intravenous methylprednisolone. Computed tomography (CT) scan showed features consistent with a diagnosis of probable cerebral toxoplasmosis. He responded dramatically to antitoxoplasma therapy. To our knowledge, this is the first case report in the literature that presents a newly diagnosed SLE patient who rapidly developed cerebral toxoplasmosis following administration of intravenous methylprednisolone. Our case illustrates that this drug is potentially fatal and the importance of differentiating cerebral infection from neuropsychiatric lupus.

An analysis of three opportunistic infections in an outpatient HIV clinic in Jamaica

OBJECTIVES

To determine the occurrence of opportunistic infection (OI) in HIV-positive patients and to identify any risk factors which may be associated with such.

METHODS

A cross-sectional study of all patients attending the HIV out-patient clinic was conducted. Their hospital notes were examined between January 1 and December 31, 2007 inclusive, to identify any occurrence of opportunistic infection. In addition, the patient list was also cross-referenced with all patients hospitalized on the medical wards during the same time period. Clinical and demographic data were collected for all participants. The occurrence of opportunistic infections and the variables of age, gender CD4 counts and viral loads: (first ever last in 2007 and at diagnosis of OI [or within six months]), the use of primary and secondary prophylaxis, the discontinuation of prophylactic regimens and the HAART regime at diagnosis of an OI and the diagnostic and treatment protocols of these infections were calculated.

RESULTS

Six hundred and three patients participated in the study and 4.7% (n = 28) were found to have experienced at least one opportunistic infection in 2007. Significant associations were found between first and last CD4 cell count, viral load in 2007, year of entry into the clinic and death (p < 0.05).

CONCLUSIONS

Opportunistic infections continue to cause significant morbidity and mortality in the HIV-patient population in this study. Earlier entry to treatment facilities and the use of HAART and appropriate prophylaxis can reduce this impact and lead to improved quality of life for HIV-positive individuals.

Trimethoprim as adjuvant treatment in schizophrenia: a double-blind, randomized, placebo-controlled clinical trial

Various infectious agents, such as Toxoplasma gondii, have been hypothesized to be potentially relevant etiological factors in the onset of some cases of schizophrenia. We conducted a randomized, double-blind, placebo-controlled treatment trial in an attempt to explore the hypothesis that the symptoms of schizophrenia may be related to infection of the central nervous system with toxoplasma gondii. Systematically selected patients with ongoing and at least moderately severe schizophrenia from Butajira, in rural Ethiopia, were randomly allocated to trimethoprim or placebo, which were added on to participants' regular antipsychotic treatments. Trial treatments were given for 6 months. The Positive and Negative Syndrome Scale (PANSS) was used to assess outcome. Ninety-one patients were included in the study, with 80 cases (87.9%) positive for T. gondii immunoglobulin G antibody. Seventy-nine subjects (87.0%) completed the trial. The mean age of subjects was 35.3 (SD = 8.0) years, with a mean duration of illness of 13.2 (SD = 6.7) years. Both treatment groups showed significant reduction in the overall PANSS score with no significant between-group difference. In this sample of patients with chronic schizophrenia, trimethoprim used as adjuvant treatment is not superior to placebo. However, it is not possible to draw firm conclusion regarding the etiological role of toxoplasmosis on schizophrenia based on this study because the timing and the postulated mechanisms through which toxoplasmosis produces schizophrenia are variable.

[Cerebral toxoplasmosis complicating an allograft with hematopoietic stem cells from peripheral blood]

We report the occurrence of a cerebral toxoplasmosis 52 days after a non-myeloablative allogeneic stem cell transplantation as treatment for acute myeloid leukemia.

Cotrimoxazole for treatment of cerebral toxoplasmosis: an observational cohort study during 1994-2006

Cotrimoxazole (trimethoprim/sulfamethoxazole [TMP-SMX]) is an alternative treatment for toxoplasmic encephalitis because it is inexpensive, well-tolerated, and as effective as pyrimethamine-sulfadiazine, which is the first-line drug regimen). We report results of a large cohort study of patients with acquired immunodeficiency syndrome who were treated for toxoplasmic encephalitis with cotrimoxazole. The mean follow-up period was more than three years. Our results confirm that cotrimoxazole is effective (85.5%), with a relatively low incidence of side effects (22%; 7.4% requiring treatment interruption). Relapse occurred in 30.1% of the patients at a mean +/- SD of 7.8 +/- 16.2 months after the first episode. The only risk factor for relapse was poor treatment and/or prophylaxis adherence. Mortality was significantly higher (P < 0.05) before 1996 than after 1996 (the era of highly active antiretroviral therapy). There was a non-significant trend towards a higher rate of relapse among patients treated before 1996 (P = 0.06). Consequently, cotrimoxazole could be a first-line drug regimen for curative treatment and prophylaxis of toxoplasmic encephalitis.

Subacute onset of paralysis in a person with AIDS

We report a case of subacute onset of paraparesis in a patient with AIDS. Empiric treatment for toxoplasmosis of the brain and the spinal cord resulted in resolution of the paraparesis. This case highlights the differential diagnosis of toxoplasmosis of the spinal cord and reviews its management in HIV-infected patients.

Clinical presentation and outcome of toxoplasmic encephalitis in patients with human immunodeficiency virus type 1 infection

BACKGROUND AND PURPOSE

Clinical manifestations and outcome of toxoplasmic encephalitis (TE) in patients at late stage of human immunodeficiency virus (HIV) infection have not been previously reported in Taiwan. The aim of this study was to describe the clinical and radioimaging characteristics and treatment response in HIV-infected patients with TE in Taiwan.

METHODS

Medical records of all HIV-infected patients who were diagnosed as having TE between June 1994 and December 2006 at the National Taiwan University Hospital, Taipei, Taiwan, were reviewed by use of a standardized case record form. Diagnosis of TE was based on clinical manifestations, serology, and radioimaging findings plus clinical and radiographic response to anti-toxoplasmosis therapy.

RESULTS

During the 12-year study period, 18 patients (1.2%) with 19 episodes of TE were identified. The median CD4+ lymphocyte count was 15 cells/microL and plasma HIV RNA load was 179,000 copies/mL at the diagnosis of TE. TE was the initial presentation of HIV infection in around two-thirds of the patients. Fever, focal neurological deficit, cognitive dysfunction, and altered mental status were the most common presenting symptoms. The typical radioimaging findings, multiple enhanced lesions with mass effect, were most common in the cerebral cortex, followed by the basal ganglia, cerebellum and brain stem. Compared with those who survived TE, the 3 patients who died of TE were older (52 vs 37 years, p=0.016) and had a higher incidence of cognitive impairment (100.0% vs 37.5%, p=0.063) and altered mental status (100.0% vs 18.8%, p=0.025).

CONCLUSIONS

TE was a rare HIV-related infectious complication in our cohort. Advanced age and altered mental status were associated with an increased mortality in HIV-infected patients with TE.

Clinical and diagnostic management of toxoplasmosis in the immunocompromised patient

With the advent of the highly active antiretroviral therapy (HAART), the natural course of HIV infection has markedly changed and opportunistic infections including toxoplasmosis have declined and modified in presentation, outcome and incidence. However, TE is a major cause of morbidity and mortality especially in resource-poor settings but also a common neurological complication in some countries despite the availability of HAART and effective prophylaxis. In most cases toxoplasmosis occurs in brain and toxoplasmic encephalitis (TE) is the most common presentation of toxoplasmosis in immunocompromised patients with or without AIDS. The need of a definitive diagnosis is substantial because other brain diseases could share similar findings. Rapid and specific diagnosis is thus crucial as early treatment may improve the clinical outcome. Classical serological diagnosis is often inconclusive as immunodeficient individuals fail to produce significant titres of specific antibodies. Polymerase chain reaction (PCR) has a high diagnostic value in the acute disease, but like many 'in-house' PCR assays, suffers from lack of standardization and variable performance according to the laboratory. Molecular diagnosis of toxoplasmosis can be improved by performing real-time PCR protocols. This article summarises the clinical manifestations, diagnostic procedures and management strategies for this condition.

Toxoplasma gondii brain granuloma in a cat: diagnosis using cytology from an intraoperative sample and sequential magnetic resonance imaging

A cat with a history of seizures and clinical suspicion of forebrain disorder underwent a brain magnetic resonance imaging. A space-occupying lesion was identified in the left temporal lobe. The mass was surgically removed, and cytological, histological and immunohistochemical examinations documented the presence of Toxoplasma gondii. A definitive diagnosis of an intracranial T gondii granuloma was made. The cat was treated with clindamycin and phenobarbital and the seizures did not recur. After 10 months, a second magnetic resonance imaging showed severe brain atrophy, but T gondii granuloma recurrence was not noted. Twenty-one months after surgery, the cat's condition deteriorated, and another magnetic resonance imaging showed a presumptive recurrence of T gondii granuloma. In cats, T gondii granuloma must be considered as a differential diagnosis even when only a single intracranial mass is present. Cytology and magnetic resonance imaging can be useful in making a definitive diagnosis and to follow the evolution of the lesion.

Cerebral toxoplasmosis in an allogeneic peripheral stem cell transplant recipient: case report and review of literature

We present a patient who underwent allogeneic peripheral stem cell transplantation (PSCT) for chronic myelocytic leukemia. Twenty months after the PSCT he experienced status epilepticus. Magnetic resonance imaging (MRI) revealed a focus in the ventral thalamus-hypothalamus region. Using stereotactic biopsy with histology and specific polymerase chain reaction investigation from brain tissue, cerebral toxoplasmosis was diagnosed and treated with antiparasitic therapy. Early recognition of such serious and potentially lethal disease enabled prompt specific treatment. This case report emphasizes the role of stereotactic biopsy in diagnosis of cerebral toxoplasmosis. Other methods such as MRI are non-invasive but not sufficiently specific and sensitive.

Disseminated Balamuthia mandrillaris amoeba infection in an AIDS patient from Brazil

This report describes a 32-year-old male AIDS patient. He presented with a clinical picture characterized by severe headache, blurred vision, and fever that had lasted for 10 days. At admission, no remarkable neurologic abnormalities were observed. Cranial tomography showed a ring-enhanced lesion with edema and a mass effect in the right occipital lobe. The initial diagnosis was toxoplasmosis, and treatment of this was administered. However, 5 days later, the patient's clinical status worsened and he died. The necropsy showed necrotizing and hemorrhagic encephalitis, with trophozoites similar to an amoeba species. Furthermore, the kidneys, adrenal glands, thyroid gland, and liver were also involved. The amoeba Balamuthia mandrillaris was identified by an immunofluorescence test.

Treating AIDS-associated cerebral toxoplasmosis - pyrimethamine plus sulfadiazine compared with cotrimoxazole, and outcome with adjunctive glucocorticoids

We conducted a retrospective study of AIDS-associated cerebral toxoplasmosis. Eighteen patients received pyrimethamine plus sulfadiazine and 25 co-trimoxazole, with comparable baseline characteristics. There were no differences in clinical outcomes, but co-trimoxazole was better tolerated (p = 0.066). There was also a trend towards more deaths among patients who received glucocorticoids.

The timing of sulfadiazine therapy impacts the reactivation of latent Toxoplasma infection in IRF-8−/− mice

The process of reactivation of latent infection with Toxoplasma gondii in immunosuppressed hosts is yet not fully understood. In the past, a number of murine models of reactivation in immunocompromised mice have been described using sulfadiazine to establish latent infection before withdrawal and subsequent reactivation. We studied the process of reactivation in brains of mice with a targeted mutation in the interferon-regulatory factor (IRF)-8 gene after withdrawal of sulfadiazine therapy. IRF-8(-/-) mice were orally infected with five cysts of the ME 49 strain of T. gondii. To allow establishment of latent infection with cyst formation, mice were treated with sulfadiazine starting either 3, 5, 6, or 7 days postinfection. Sulfadiazine was withdrawn after 14-21 days to allow reactivation. We observed that timing of sulfadiazine therapy had a marked impact on the course of infection and reactivation. Mice treated late after infection (days 5-7) showed increased mortality and decreased time to death compared to mice treated early after infection (group A). In the blood of mice with late (days 5-7) but not early (day 3) initiation of treatment, T. gondii-specific deoxyribonucleic acid was detected by polymerase chain reaction. Using double staining with stage-specific antibodies, tachyzoites were detectable in brains of mice with late initiation of sulfadiazine treatment but rarely within cysts thus indicating continued invasion of parasites across the blood-brain barrier. Intracerebral cyst rupture or bradyzoite-tachyzoite conversion was not detectable in IRF-8(-/-) mice when sulfadiazine therapy was initiated late after infection. These results indicate that continued invasion of tachyzoites rather than reactivation of latent cerebral infection impacts the course of infection in this model of reactivated toxoplasmosis. In conclusion, the timing of sulfadiazine therapy is of utmost importance for the course of infection in immunocompromised mice.

Toxoplasmosis encephalitis following severe graft-vs.-host disease after allogeneic hematopoietic stem cell transplantation: 17 yr experience in Fukuoka BMT group

Toxoplasmosis is a rare but rapidly fatal complication that can occur following hematopoietic stem cell transplantation (HSCT). Over a 17-yr period at our institutions, a definite diagnosis of toxoplasmosis was made in only two of 925 allogeneic HSCT recipients (0.22%) and none of 641 autologous HSCT recipients. These two patients received a conventional conditioning regimen followed by transplantation from an HLA-matched donor; however, they developed severe graft-vs.-host disease, which required intensive immunosuppressive therapy. Despite prophylactic treatment with trimethoprim/sulfamethoxazole, their immunosuppressive state, as indicated by a low CD4(+) cell count, might have resulted in toxoplasmosis encephalitis. Rapid and non-invasive methods such as a polymerase chain reaction (PCR) test of their cerebrospinal fluid for Toxoplasma gondii and magnetic resonance imaging of the brain were useful for providing a definitive diagnosis and prompt therapy in these patients: one patient stabilized and survived after responding to treatment with pyrimethamine/sulfodiazine whereas the other died of bacterial infection. In addition, retrospective PCR analyses of the frozen stored peripheral blood samples disclosed that detection of T. gondii preceded the onset of disease, indicating routine PCR testing of peripheral blood specimens may be an early diagnostic tool. It should be noted that when patients receiving HSCT have an unexplained fever and/or neurological complications, PCR tests should be considered to avoid cerebral lesions and improve the outcome of the patients.

Severe Toxoplasma gondii I/III recombinant-genotype encephalitis in a human immunodeficiency virus patient

The reactivation of an uncommon type I/III recombinant-genotype Toxoplasma gondii strain resulted in unusually severe encephalitis and chorioretinitis associated with a cerebral salt wasting syndrome in an African human immunodeficiency virus patient. This observation suggests an influence of the parasite genotype on disease expression in immunocompromised patients.

Randomized Controlled Trial of Pyrimethamine Plus Sulfadiazine Versus Trimethoprim Plus Sulfamethoxazole for Treatment of Toxoplasmic Encephalitis in AIDS Patients

Background: Toxoplasmic encephalitis (TE), caused by Toxoplasma gondii, is common in AIDS patients. TE can result in tissue destruction via massive inflammation and brain abscess formation. Methods: Randomized controlled trials were performed in AIDS patients to assess which drug regimen was optimally effective for the treatment of TE. AIDS patients with TE were randomly divided into 3 groups that received a 6-week course of either pyrimethamine (50 mg/ day or 100 mg/day) plus sulfadiazine (4 g/day) and folinic acid (25 mg/day) or trimethoprim (10 mg/kg/day) plus sulfamethoxazole (50 mg/kg/day) (TMP-SMX), and results were evaluated with respect to clinical response, mortality, morbidity, and serious adverse events. The primary outcome was defined as death in the first 6-week period. The secondary outcome was successful treatment within 6 weeks without severe adverse events, bone marrow suppression, drug-induced rash, or any other event that caused a change in the treatment regimen. Results: The results from this study showed that in AIDS patients, TE was most successfully treated with the combination of pyrimethamine (50 mg/day) plus sulfadiazidine (4 g/day) and folinic acid (25 mg/day); failure rates were not significantly different among the 3 treatment groups. Conclusions: Available data suggest that of the currently available options, treatment of TE with pyrimethamine at 50 mg/day plus sulfadiazidine at 4 g/day provides the best primary outcome for AIDS patients with TE; however, because this study was terminated prematurely, we suggest that treatment with intravenous TMP-SMX be further evaluated to determine its efficacy.

[Acute renal failure due to sulfadiazine crystalluria]

Focal necrotizing encephalitis due to Toxoplasma gondii infection represents one of the most common opportunistic infection in patients with the acquired inmunodeficiency syndrome (AIDS), and the treatment is commonly with a combination sulphadiazine, and pyrimethamine. A major side effect of sulfadiazine therapy is the occurrence of crystallization in the urinary collecting system. We report a patient with AIDS and Toxoplasmic encephalitis treated with sulfadiazine who developed acute renal failure. Renal ultrasound demonstrated echogenic areas within the renal parenchyma, presumed to be sulfa crystals. Renal failure and ultrasound findings resolved rapidly with hydratation and administration of alkali. Patients infected with AIDS frequently have characteristic that increase intratubular crystal precipitation and they require treatment with one or more of the drugs that are associated with crystal-induced renal failure. Controlled alkalinization of the urine and high fluid intake are recommended for prophylaxis of crystalluria. The literature concerning crystalluria and renal failure due to sulfadiazine is reviewed.