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.

An unusual cause of isolated secondary ovarian failure due to cerebral toxoplasmosis in an African woman with AIDS.

Primary ovarian failure is common. However, isolated secondary ovarian failure due to gonadotrophin deficiency is rare. A few cases of isolated gonadotrophin deficiency, due to congenital cerebral toxoplasmosis, have been described in children. We report the case of a 34-year-old African woman positive for HIV, who developed secondary amenorrhoea following the successful treatment of cerebral toxoplasmosis. Investigations revealed that she developed an isolated gonadotrophin deficiency due to pituitary lesion. The rest of the pituitary function dynamic tests were normal.

Clinical presentation and outcome of toxoplasma encephalitis in HIV-infected patients from Zaria, Northern Nigeria: a case series of 9 patients.

Toxoplasma encephalitis (TE) is the most common cause of focal deficits in patients living with HIV/AIDS. Among 257 HIV-infected adult patients seen between January 2006 and December 2010 in a tertiary hospital in Zaria, northern Nigeria, 9 (3.5%) patients had clinical, serological, and brain imaging evidence of TE. All 9 patients had CD4 count of less than 50 cells/mm(3). Of the 9 patients, 7 were antiretroviral therapy (ART)-naive, while 2 were cases of ART-induced TE-immune reconstitution inflammatory syndrome. After administering intravenous dexamethasone for cerebral decompression and specific antitoxoplasma therapy, symptoms and signs resolved in 8 patients within 4 to 14 days, but 1 patient died. Our data suggest that even in the ART era in Nigeria, TE remains a fairly common cause of morbidity among HIV-infected patients due to late HIV diagnosis and significant immunosuppression at diagnosis. Early HIV diagnosis, early initiation of highly active ART, and routine prophylaxis against TE are imperative in combating the challenge of HIV/AIDS-related TE in Nigeria.

Toxoplasma encephalitis in an HIV-infected patient on highly active antiretroviral therapy despite sustained immune response.

Toxoplasma encephalitis (TE) is usually diagnosed in advanced stages of HIV infection when the CD4+ count is <100-200 cells/µl. A 55-year-old woman with HIV/AIDS, well controlled on antiretroviral therapy (ART), CD4+ count in the 300 cells/µl range for >1 year presented with acute onset of headache, nausea and vomiting. She had been on her current ART regimen consisting of raltegravir, co-formulated emtricitabine/tenofovir and etravirine for three years and had been off Pneumocystis prophylaxis for 10 months (trimethoprim-sulfamethoxazole). Brain MRI showed multiple ring-enhancing, supratentorial and infra-tentorial parenchymal lesions suspicious for metastases. She had no other evidence of metastatic disease in her body. The possibilities of TE and primary CNS lymphoma were considered but deemed unlikely given the high CD4+ count. A brain biopsy demonstrated Toxoplasma tachyzoites. There was no evidence of lymphoma or carcinoma. Anti-toxoplasma treatment yielded good initial clinical and radiographic responses. While on TE maintenance therapy, she developed similar symptoms. Repeat MRI showed progression of lesions. Further work-up including CSF Epstein-Barr virus PCR and SPECT Th 201 imaging was not conclusive for CNS lymphoma. The patient's clinical condition deteriorated and she died. We postulate that functional immunological dysfunction is a possible mechanism by which our patient developed TE despite demonstrating sustained immune response on ART.

High-intensity signals in the basal ganglia from gadolinium-enhanced T1-weighted MRI as an early change in toxoplasma encephalitis in an AIDS patient.

A 30-year-old Brazilian man hospitalized with AIDS developed a high-grade fever. Neither culture studies nor radiological examinations revealed the cause; small yet highly intense signals in the basal ganglia were detected upon gadolinium (Gd)-enhanced T1-weighted magnetic resonance imaging (MRI) of the head. This finding was equivocal at that time but obviously abnormal for his age. A week later, he developed a movement disorder in his right arm, speech apraxia, and a worsening disturbance of consciousness. Repeated Gd-enhanced T1-weighted MRI demonstrated incredible changes in the brain; enhanced lesions in the basal ganglia deteriorated over time, multiple nodular and ring-enhanced lesions were observed in almost the entire brain. A diagnosis of toxoplasma encephalitis (TE) was confirmed by the detection of Toxoplasma gondii DNA in the cerebrospinal fluid. After initiation of intravenous trimethoprim-sulfamethoxazole (TMP-SMX; 10 mg/kg/day of TMP and 50 mg/kg/day of SMX) treatment, his symptoms and radiological findings improved dramatically. Our case suggests that high-intensity signals seen in the basal ganglia of a Gd-enhanced T1-weighted MRI, even at the preclinical stage, is indicative of TE. Because the use of MRI in general has become more widespread, it is predicted that preclinical lesions of TE will be found in various clinical settings more frequently.

Drug-to-drug interaction between dapsone and minocycline: an unusual cause of relapse of toxoplasmic encephalitis in an HIV-infected patient.

HIV-infected patients with opportunistic infections receive therapeutic regimens that often contain numerous drugs and are then exposed to potential drug-to-drug interactions. We report here an unusual case of relapse of toxoplasmic encephalitis in an HIV-infected patient, possibly due to a drug-to-drug interaction between dapsone and minocycline.

Impaired CD4-cell immune reconstitution upon HIV therapy in patients with toxoplasmic encephalitis compared to patients with pneumocystis pneumonia as AIDS indicating disease.

OBJECTIVES: There is only little data on immune reconstitution in antiretroviral naive AIDS-patients with toxoplasmosis. The observation of several cases with reduced increase of CD4-cells upon start of antiretroviral treatment (ART) prompted us to investigate the topic using the ClinSurv cohort. METHODS: 17 German HIV treatment centers contribute to ClinSurv, a multicentre observational cohort under the auspices of the Robert Koch Institute. We retrospectively selected all antiretroviral-naive patients with toxoplasmic encephalitis (TE) and - as comparator group - with pneumocystosis (PCP) between January 1999 and December 2005. RESULTS: A total of 257 patients were included in the analysis, 61 with TE and 196 with PCP. Demographic baseline data showed differences with regard to gender, transmission group, and baseline CD4 superset+ counts (60.9 vs. 44.7/microl, p = 0.022). After ART-initiation the increase in CD4 superset+ lymphocytes was lower in the TE- versus the PCP-group in the first, second and fourth three-month-period (74.4 vs. 120.3/microl, p = 0.006; 96.6 vs. 136.2/microl, p = 0.021; 156.5 vs. 211.5/microl, p = 0.013). Viral load (VL) was higher in the PCP-group at baseline (4.46 log subset10cop/ml vs. 5.00 log subset10cop/ml, p = 0.008), while virological success of ART was equal. CONCLUSIONS: Our data show for the first time that the average CD4 superset+ T-cell increase of patients with toxoplasmosis is impaired compared to PCP-patients. Most clinicians would not be prepared to discontinue follow-up TE-therapy unless CD4 superset+ counts of 200/microl are reached. Explanation for our finding might be the myelosuppressive side effect of pyrimethamine, possible interactions of toxoplasmosis therapy with ART, or an unknown direct biological influence of toxoplasmosis on immune restoration.

An exploratory study of long-term neurocognitive outcomes following recovery from opportunistic brain infections in HIV+ adults.

Central nervous system opportunistic infections (CNS-OI) are a significant cause of morbidity and mortality in AIDS. While current interventions are increasingly successful in treating CNS-OI, little information exists regarding long-term behavioral outcomes among survivors. In this exploratory study we examined neurocognitive data among three groups of adults with different AIDS-related CNS-OI: 15 with past cryptococcal meningitis (CM), 8 with toxoplasmosis encephalitis (TE), and 8 with progressive multifocal leukoencephalopathy (PML). A group of 61 individuals with AIDS, but without CNS-OI, was used as a comparison group. A battery of standardized neuropsychological tests assessing a variety of cognitive domains was administered upon entry. Results indicate that individuals with a history of CNS-OI were most impaired on measures of cognitive and psychomotor speed relative to the HIV+ comparison group. Among the CNS-OI groups, individuals with history of TE had the most severe and varied deficits. The results are discussed in relation to what is known about the neuropathological consequences of the various CNS-OIs. While this is the first systematic group study of residual CNS-OI effects on neurocognitive function, future studies employing more participants, perhaps focusing on specific CNS-OIs, will further characterize the long-term outcomes in AIDS-related CNS-OI.

Factors influencing cerebrospinal fluid and plasma HIV-1 RNA detection rate in patients with and without opportunistic neurological disease during the HAART era.

BACKGROUND: In the central nervous system, HIV replication can occur relatively independent of systemic infection, and intrathecal replication of HIV-1 has been observed in patients with HIV-related and opportunistic neurological diseases. The clinical usefulness of HIV-1 RNA detection in the cerebrospinal fluid (CSF) of patients with opportunistic neurological diseases, or the effect of opportunistic diseases on CSF HIV levels in patients under HAART has not been well defined. We quantified CSF and plasma viral load in HIV-infected patients with and without different active opportunistic neurological diseases, determined the characteristics that led to a higher detection rate of HIV RNA in CSF, and compared these two compartments. METHODS: A prospective study was conducted on 90 HIV-infected patients submitted to lumbar puncture as part of a work-up for suspected neurological disease. Seventy-one patients had active neurological diseases while the remaining 19 did not. RESULTS: HIV-1 RNA was quantified in 90 CSF and 70 plasma samples. The HIV-1 RNA detection rate in CSF was higher in patients with neurological diseases, in those with a CD4 count lower than 200 cells/mm3, and in those not receiving antiretroviral therapy, as well as in patients with detectable plasma HIV-1 RNA. Median viral load was lower in CSF than in plasma in the total population, in patients without neurological diseases, and in patients with toxoplasmic encephalitis, while no significant difference between the two compartments was observed for patients with cryptococcal meningitis and HIV-associated dementia. CSF viral load was lower in patients with cryptococcal meningitis and neurotoxoplasmosis under HAART than in those not receiving HAART. CONCLUSION: Detection of HIV-1 RNA in CSF was more frequent in patients with neurological disease, a CD4 count lower than 200 cells/mm3 and detectable plasma HIV-1. Median HIV-1 RNA levels were generally lower in CSF than in plasma but some patients showed higher CSF levels, and no difference between these two compartments was observed in patients with cryptococcal meningitis and HIV-associated dementia, suggesting the presence of intrathecal viral replication in these patients. HAART played a role in the control of CSF HIV levels even in patients with cryptococcal meningitis and neurotoxoplasmosis in whom viral replication is potentially higher.

HIV infection with concomitant cerebral toxoplasmosis and disseminated histoplasmosis in a 45-year-old man.

Although disseminated histoplasmosis is a common opportunistic infection in HIV patients in endemic areas, it is not widely known in Japan. We report a rare case of a man from Ghana infected with HIV who was hospitalized in Japan and who suffered from coinfection with cerebral toxoplasmosis and disseminated histoplasmosis. The diagnosis of cerebral toxoplasmosis was confirmed by a brain biopsy, and the therapy for the disease resulted in almost complete resolution of the brain lesion. However, fever of unknown origin continued for 2 weeks, and disseminated histoplasmosis was diagnosed by examination of a blood smear and by the detection of the histoplasma genome in the peripheral blood by means of polymerase chain reaction. The isolate was confirmed to be Histoplasma capsulatum var. duboisii. Therapy with amphotericin B was initiated, and no histoplasma genome in the peripheral blood was detected 3 days later. Unfortunately, the patient died after 10 days from acute respiratory syndrome. This case highlights that histoplasmosis should be included in the differential diagnosis of opportunistic infections in AIDS patients when patients have a history of travel to or arrival from endemic areas.

Maintenance therapy with cotrimoxazole for toxoplasmic encephalitis in the era of highly active antiretroviral therapy.

To reduce the number of daily pills for improving adherence to antiretrovirals, 17 protease inhibitor-treated patients receiving toxoplasmic encephalitis (TE) standard maintenance therapy were instead given cotrimoxazole 960 mg twice daily. After a median follow-up of 31 months, one relapsed after three months, TE relapse incidence = 2.1 cases per 100 patient-years (95% confidence interval, 0.05-11.3). This strategy could be useful for patients awaiting immune reconstitution which allows the interruption of TE maintenance therapy.

HIV and the central nervous system.

Neurological complications of HIV infection are common with clinically recognized disorders ultimately affecting between 40% and 75% of patients. The spectrum of neurological disease is broad. This article highlights the common disorders of the central nervous system associated with HIV/AIDS.

Chorea in patients with AIDS.

OBJECTIVE: To describe differing etiologies and possible anatomoclinical correlates of choreic movements in a series of AIDS patients. METHODS: We analyzed the clinical records and neuroimaging data of 5 consecutive AIDS patients who developed choreic movements at our center from January, 1994 to December, 1996. RESULTS: There were 2 cases of focal choreic dyskinesias, 1 of right hemichorea, and 2 of generalized chorea. Onset was acute and febrile in 1 case, and subacute in the other 4. In 1 patient the chorea was the AIDS onset symptom; in another choreic movements were the first neurological symptom following AIDS diagnosis; in 2 patients AIDS had a neurological onset other than chorea; and in the fifth patient buccofacial dyskinesias appeared following the development of bacterial encephalitis. CONCLUSION: Chorea was associated with cerebral toxoplasmosis in 2 patients, progressive multifocal leukoencephalopathy in 1, subacute HIV encephalopathy in another, and was probably iatrogenic in the last. Chorea is not unusual in AIDS, however the causes are variable and careful neuroradiological and clinical evaluation is required to identify them. AIDS-related disease should be considered in young patients presenting with chorea without a family history of movement disorders.

Localised 1H-MR spectroscopy for metabolic characterisation of diffuse and focal brain lesions in patients infected with HIV.

OBJECTIVES: To evaluate the role of proton MR spectroscopy (1H-MRS) in detecting metabolic changes in diffuse or focal lesions in the brain of patients infected with HIV. METHODS: Sixty HIV seropositive patients (25 with HIV related encephalopathies, 20 with toxoplasmosis, eight with progressive multifocal leukoencephalopathies (PMLs), and seven with lymphomas) and 22 HIV seronegative neurological controls were examined with a combined MRI and 1H-MRS technique using a Siemens 1.5 Tesla Magnetom. Spectra (Spin Echo sequence, TE 135 ms) were acquired by single voxel, localised on focal lesions in toxoplasmosis, PML, lymphomas, and HIV encephalopathies and on the centrum semiovale of neurological controls. Choline (Cho), creatine (Cr), N-acetyl aspartate (NAA), lactate, and lipids were evaluated in each spectrum and NAA/Cr, NAA/Cho, and Cho/Cr ratios were calculated. RESULTS: A significant decrease in NAA/Cr and NAA/Cho ratios were found in all HIV diagnostic groups in comparison with neurological controls (p<0.003), suggesting neuronal or axonal damage independent of brain lesion aetiology. However, the NAA/Cr ratio was significantly lower in PML and lymphomas than in HIV encephalopathies (p<0.02) and toxoplasmosis (p<0.05). HIV encephalopathies, lymphomas, and toxoplasmosis showed a significant increase in the Cho/Cr ratio in comparison with neurological controls (p<0.03) without between group differences. The presence of a lipid signal was more frequent in lymphomas (71%) than in other HIV groups (Fisher's test, p=0.00003). The presence of mobile lipid resonance together with a high Cho/Cr ratio in lymphomas may be related to an increased membrane synthesis and turnover in tumour cells. A lactate signal (marker of inflammatory reaction), was found in all but one patient with PML lesions (75%), but had a lower incidence in the other HIV diagnostic groups (Fisher's test, p=0.00024). CONCLUSION: 1H-MRS shows a high sensitivity in detecting brain involvement in HIV related diseases, but a poor specificity in differential diagnosis of HIV brain lesions. Nevertheless, the homogeneous metabolic pattern that characterises PML suggests the usefulness of 1H-MRS as an adjunct to MRI in differentiating CNS white matter lesions, such as HIV encephalopathies, from PML.

Twice-weekly maintenance therapy with sulfadiazine-pyrimethamine to prevent recurrent toxoplasmic encephalitis in patients with AIDS. Spanish Toxoplasmosis Study Group.

OBJECTIVE: To evaluate the efficacy of twice-weekly maintenance therapy with sulfadiazine-pyrimethamine to prevent toxoplasmic encephalitis relapse in patients with the acquired immunodeficiency syndrome (AIDS). DESIGN: Randomized, open, multicenter trial. Patients were randomly assigned to receive sulfadiazine (500 mg) four times per day plus pyrimethamine (25 mg) plus folinic acid (15 mg) either daily (n = 60) or twice weekly (n = 45). SETTING: 8 university teaching hospitals. PATIENTS: Between February 1990 and June 1993, 105 patients with HIV infection were enrolled after each had had resolution of an acute episode of toxoplasmic encephalitis treated with sulfadiazine (1 g four times per day) plus pyrimethamine (50 mg/d) plus folinic acid (15 mg/d) for 4 to 8 weeks. MEASUREMENTS: Clinical and biological evaluations done every 30 to 60 days. End points were toxoplasmic encephalitis relapse, death, and interruption of therapy due to adverse reactions. RESULTS: After a median follow-up period of 11 months (range, 1 to 39 months), patients receiving the twice-weekly regimen had a higher rate of relapse then patients receiving the daily regimen (19.5 compared with 4.4 per 100 patient-years; incidence rate ratio, 4.36 [95% CI, 1.05 to 25.5]; P = 0.024). The estimated cumulative percentages of relapse at 12 months were 30% and 6%, respectively (P = 0.029), with an adjusted risk ratio (adjusted for age, sex, risk behavior, previous diagnosis of AIDS, Pneumocystis carinii pneumonia prophylaxis before initial episode of toxoplasmosis, CD4 cell count, baseline number of brain lesions, radiologic sequelae, and antiretroviral therapy during follow-up) of 5.6 (CI, 1.2 to 25.6; P = 0.028). Patients receiving the twice-weekly regimen had 1.6 times (CI, 0.9 to 2.9 times; P = 0.11) the adjusted risk for death of patients receiving the daily regimen. No statistical differences were found in the patients who stopped receiving the regimens due to adverse effects. No patient developed P. carinii pneumonia during the study period, even though 17 patients (10 receiving the daily regimen and 7 receiving the twice-weekly regimen) had had an episode of P. carinii pneumonia before study entry. CONCLUSIONS: At the given doses, a combination of sulfadiazine, pyrimethamine, and folinic acid was less effective when administered twice weekly than when administered daily, although the twice-weekly regimen was much more effective than historic controls.