Neurological complications of HIV infection in pre-HAART and HAART era: a retrospective study

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

Background

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

Methods

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

Results

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

Conclusion

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

Occludin Regulates HIV-1 Infection by Modulation of the Interferon Stimulated OAS Gene Family

HIV-1-associated blood brain barrier (BBB) alterations and neurocognitive disorders are frequent clinical manifestations in HIV-1 infected patients. The BBB is formed by cells of the neurovascular unit (NVU) and sealed together by tight junction proteins, such as occludin (ocln). Pericytes are a key cell type of NVU that can harbor HIV-1 infection via a mechanism that is regulated, at least in part, by ocln. After viral infection, the immune system starts the production of interferons, which induce the expression of the 2'-5'-oligoadenylate synthetase (OAS) family of interferon stimulated genes and activate the endoribonuclease RNaseL that provides antiviral protection by viral RNA degradation. The current study evaluated the involvement of the OAS genes in HIV-1 infection of cells of NVU and the role of ocln in controlling OAS antiviral signaling pathway. We identified that ocln modulates the expression levels of the OAS1, OAS2, OAS3, and OASL genes and proteins and, in turn, that the members of the OAS family can influence HIV replication in human brain pericytes. Mechanistically, this effect was regulated via the STAT signaling. HIV-1 infection of pericytes significantly upregulated expression of all OAS genes at the mRNA level but selectively OAS1, OAS2, and OAS3 at the protein level. Interestingly no changes were found in RNaseL after HIV-1 infection. Overall, these results contribute to a better understanding of the molecular mechanisms implicated in the regulation of HIV-1 infection in human brain pericytes and suggest a novel role for ocln in controlling of this process.

Brain opportunistic infections and tumors in people living with HIV - still a challenge in efficient antiretroviral therapy era

The aim of the study was to evaluate the incidence of brain opportunistic pathologies and survival in patients living with HIV from a Romanian tertiary center. A 15-year prospective observational study of brain opportunistic infections diagnosed in HIV-infected patients was performed at Victor Babes Hospital, Bucharest, between January 2006 and December 2021. Characteristics and survival were compared related to modes of HIV acquisition and type of opportunistic infection. A total of 320 patients were diagnosed with 342 brain opportunistic infections (incidence 9.79 per 1000 person-years), 60.2% males with median age at diagnosis of 31 years (IQR 25, 40). Median CD4 cell count and VL were 36/μL (IQR 14, 96) and 5.1 log10 copies/mL (IQR 4, 5.7) respectively. The routes of HIV acquisition were heterosexual (52.6%), parenteral route in early childhood (31.6%), injecting drug use (12.9%), men having sex with men (1.8%), and vertical (1.2%). The most common brain infections were progressive multifocal leukoencephalopathy (31.3%), cerebral toxoplasmosis (26.9%), tuberculous meningitis (19.3%), and cryptococcal meningitis (16.7%). Patients infected by parenteral mode in early childhood were younger at diagnosis of both opportunistic infection and HIV (p < 0.001 and p < 0.001, respectively), developed more frequently PML (p < 0.001), and had the lowest early (p = 0.002) and late (p = 0.019) mortality rates. Risk factors for shorter survival were age > 30 years (p = 0.001), injecting drug use (p = 0.003), CD4 +  < 100/μL (p = 0.007), and VL > 5 log10 copies/mL at diagnosis (p < 0.001). The incidence and mortality rate of brain opportunistic infections were high and did not decrease significantly during the study period, due to late presentation or non-adherence to ART.

Neurologic Care of Forcibly Displaced Persons: Emerging Issues in Neurology

There is a growing number of forcibly displaced persons (FDPs) worldwide. With more than 100 million people forcibly displaced today, there is an urgent mandate to understand the neurologic care needs of this population and how neurologists and other health care workers can most effectively provide that care. In this Emerging Issues in Neurology article, we attempt to (1) define the scope of the problem of providing neurologic care to FDPs, (2) highlight commonly encountered clinical challenges related to neurologic care of FDPs, and (3) provide useful clinical information for neurologists and other clinicians who deliver care to FDPs with neurologic needs. We address the terminology of forcible displacement and how terms may differ across a person's migration journey. Common challenges encountered by FDPs with neurologic needs across settings include loss of support systems, loss of personal health information, language barriers and differing expression of symptoms, differing belief systems, epidemiologic patterns of disease unfamiliar to the clinician, and patients' fear and perceived risks of engaging with health systems. Practical approaches are shared for clinicians who encounter an FDP with a neurologic presentation. Finally, the article discusses many unmet neurologic needs of FDPs, which require significant investment. These include addressing lapses in neurologic care during displacement and understanding the effects of forcible displacement on people with chronic neurologic conditions. Future research and educational resources should focus on improving epidemiologic intelligence for neurologic conditions across geographies, developing curricula for optimizing the neurologic care of FDPs, and evaluating the most appropriate and effective uses of health technologies in humanitarian settings.

Sequelae and mortality in patients with HIV/AIDS and Progressive Multifocal Leukoencephalopathy: Systematic review and case series in the Brazilian Amazon

Background

Progressive Multifocal Leukoencephalopathy (PML) is an opportunistic neurological disease that mainly affects individuals with HIV/AIDS and has high morbidity and mortality, due to its demyelinating characteristic. This co-infection has been reported since the begging of HIV/Aids epidemic with increasing unfavorable outcomes, however, factors associated to sequelae and death are greatly unknown. In this study we aimed to understand factors associated with the main outcomes of individuals diagnosed with PML and HIV/AIDS, in addition to reporting the characteristics of patients presenting to a referral center in infectious diseases in the Brazilian Amazon.

Methods

A systematic review was performed until July 2022, following the PRISMA guidelines, at Medline/Pubmed, Web of Science, Lilacs and Scielo databases using combinations of HIV, Aids, JC Virus and Progressive Multifocal Leukoencephalopathy, with no restriction to publication date. Additional cases, meeting the eligibility criteria, were added from our hospital database, which consisted of patients presenting PML/HIV between 2010 and 2022. A meta-analysis aiming to explore factors associated to sequelae and death was performed. Baseline characteristics were described using mean and standard deviation, or median and interquartile range when appropriate; multivariate analysis was performed to study factors associated to death and sequelae outcomes.

Results

Eighteen patients were diagnosed between 2010 and 2022, of these, 10 had positive PCR for JC virus. In the Systematic Review, 216 studies yielded 235 confirmed cases of co-infection. A total of 245 were included for analysis. The rates of death and sequelae were, respectively, 47.1% (114/242) and 41.2% (54/131). The use of antiretroviral therapy was more associated with a lower chance of death (OR 0.30, 95% CI: 0.11-0.83), while muscle weakness (OR 4.82, 95% CI: 2.07-11.21) and muscle spasms (OR 6.12, 95% CI: 1.05-35.76) were associated with greater chances of sequelae.

Conclusion

Those on antiretroviral therapy appear to be less likely to die, and among those who survive, those who have muscle weakness as a symptom on admission are more likely to develop sequelae. Adherence to ART, as well as a comprehensive clinical evaluation and follow-up may help to improve clinical outcomes and awareness of morbidities.

Occludin regulates HIV-1 infection by modulation of the interferon stimulated OAS gene family

HIV-1-associated blood brain barrier (BBB) alterations and neurocognitive disorders are frequent clinical manifestations in HIV-1 infected patients. The BBB is formed by cells of the neurovascular unit (NVU) and sealed together by tight junction (TJ) proteins, such as occludin (ocln). Pericytes are a key cell type of NVU that can harbor HIV-1 infection via a mechanism that is regulated, at least in part, by ocln. After viral infection, the immune system starts the production of interferons, which induce the expression of the 2'-5'-oligoadenylate synthetase (OAS) family of interferon stimulated genes and activate the endoribonuclease RNaseL that provides antiviral protection by viral RNA degradation. The current study evaluated the involvement of the OAS genes in HIV-1 infection of cells of NVU and the role of ocln in controlling OAS antiviral signaling pathway. We identified that ocln modulates the expression levels of the OAS1, OAS2, OAS3, and OASL genes and proteins and, in turn, that the members of the OAS family can influence HIV replication in human brain pericytes. Mechanistically, this effect was regulated via the STAT signaling. HIV-1 infection of pericytes significantly upregulated expression of all OAS genes at the mRNA level but selectively OAS1, OAS2 and OAS3 at the protein level. Interestingly no changes were found in RNaseL after HIV-1 infection. Overall, these results contribute to a better understanding of the molecular mechanisms implicated in the regulation of HIV-1 infection in human brain pericytes and suggest a novel role for ocln in controlling of this process.

Clinical value of 18F-FDG PET/CT in the management of HIV-associated lymphoma

HIV is still a major public health problem. At present, HIV-associated lymphoma remains the leading cause of deaths among people living with HIV, which should be paid more attention to. ¹⁸F-fluorodeoxglucose (FDG) PET/CT has been recommended in the initial staging, restaging, response assessment and prognostic prediction of lymphomas in general population. HIV-associated lymphoma is, however, a different entity from lymphoma in HIV-negative with a poorer prognosis. The ability to accurately risk-stratify HIV-infected patients with lymphoma will help guide treatment strategy and improve the prognosis. In the review, the current clinical applications of ¹⁸F-FDG PET/CT in HIV-associated lymphoma will be discussed, such as diagnosis, initial staging, response evaluation, prognostic prediction, PET-guided radiotherapy decision, and surveillance for recurrence. Moreover, future perspectives will also be presented.

Pericyte infection by HIV-1: a fatal attraction

While HIV-1 is primarily an infection of CD4 + T cells, there is an emerging interest towards understanding how infection of other cell types can contribute to HIV-associated comorbidities. For HIV-1 to cross from the blood stream into tissues, the virus must come in direct contact with the vascular endothelium, including pericytes that envelope vascular endothelial cells. Pericytes are multifunctional cells that have been recognized for their essential role in angiogenesis, vessel maintenance, and blood flow rate. Most importantly, recent evidence has shown that pericytes can be a target of HIV-1 infection and support an active stage of the viral life cycle, with latency also suggested by in vitro data. Pericyte infection by HIV-1 has been confirmed in the postmortem human brains and in lungs from SIV-infected macaques. Moreover, pericyte dysfunction has been implicated in a variety of pathologies ranging from ischemic stroke to diabetes, which are common comorbidities among people with HIV-1. In this review, we discuss the role of pericytes during HIV-1 infection and their contribution to the progression of HIV-associated comorbidities.

CD8 Encephalitis: A Diagnostic Dilemma

CD8+ encephalitis is a subacute encephalopathy associated with HIV infection. Pathophysiology is thought to be auto-reactive CD8+ cells attacking on HIV infected CD4+ cells and ‘viral escape’ phenomena (replication of CD8+ cells in CSF). We present a case of a 45-year-old man with well controlled HIV who developed CD8 encephalitis following Herpes simplex encephalitis. He had persistent encephalopathy for several weeks with status epilepticus and agitated delirium, and diagnosis remained elusive until a brain biopsy confirmed the diagnosis.

Glutamine antagonist JHU083 improves psychosocial behavior and sleep deficits in EcoHIV-infected mice

Combined antiretroviral therapy ushered an era of survivable HIV infection in which people living with HIV (PLH) conduct normal life activities and enjoy measurably extended lifespans. However, despite viral control, PLH often experience a variety of cognitive, emotional, and physical phenotypes that diminish their quality of life, including cognitive impairment, depression, and sleep disruption. Recently, accumulating evidence has linked persistent CNS immune activation to the overproduction of glutamate and upregulation of glutaminase (GLS) activity, particularly in microglial cells, driving glutamatergic imbalance with neurological consequences. Our lab has developed a brain-penetrant prodrug of the glutamine antagonist 6-diazo-5-oxo-L-norleucine (DON), JHU083, that potently inhibits brain GLS activity in mice following oral administration. To assess the therapeutic potential of JHU083, we infected mice with EcoHIV and characterized their neurobehavioral phenotypes. EcoHIV-infected mice exhibited decreased social interaction, suppressed sucrose preference, disrupted sleep during the early rest period, and increased sleep fragmentation, similar to what has been reported in PLH but not yet observed in murine models. At doses shown to inhibit microglial GLS, JHU083 treatment ameliorated all of the abnormal neurobehavioral phenotypes. To explore potential mechanisms underlying this effect, hippocampal microglia were isolated for RNA sequencing. The dysregulated genes and pathways in EcoHIV-infected hippocampal microglia pointed to disruptions in immune functions of these cells, which were partially restored by JHU083 treatment. These findings suggest that upregulation of microglial GLS may affect immune functions of these cells. Thus, brain-penetrable GLS inhibitors like JHU083 could act as a potential therapeutic modality for both glutamate excitotoxicity and aberrant immune activation in microglia in chronic HIV infection.

Clinical and Therapeutic Implications of Epstein-Barr Virus in HIV-Related Lymphomas

The incidence of lymphomas is increased in people living with HIV (PLWH). Aggressive B-cell non-Hodgkin lymphomas (NHLs) are the most common and are considered an AIDS-defining cancer (ADC). Although Hodgkin lymphoma (HL) is not considered an ADC, its incidence is also increased in PLWH. Among all HIV-related lymphomas (HRL), the prevalence of Epstein-Barr virus (EBV) is high. It has been shown that EBV is involved in different lymphomagenic mechanisms mediated by some of its proteins, contributing to the development of different lymphoma subtypes. Additionally, cooperation between both HIV and EBV can lead to the proliferation of aberrant B-cells, thereby being an additional lymphomagenic mechanism in EBV-associated HRL. Despite the close relationship between EBV and HRL, the impact of EBV on clinical aspects has not been extensively studied. These lymphomas are treated with the same therapeutic regimens as the general population in combination with cART. Nevertheless, new therapeutic strategies targeting EBV are promising for these lymphomas. In this article, the different types of HRL are extensively reviewed, focusing on the influence of EBV on the epidemiology, pathogenesis, clinical presentation, and pathological characteristics of each lymphoma subtype. Moreover, novel therapies targeting EBV and future strategies to treat HRL harboring EBV are discussed.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Diagnosis, prevention and treatment of central nervous system involvement in peripheral t-cell lymphomas

Non-Hodgkin lymphomas with T-cell immunophenotype encompass a heterogeneous group of infrequent neoplasms that follow variable clinical courses but prevalently include aggressive behavior and high mortality rates. The involvement of the central nervous system (CNS) is an uncommon event in T-cell lymphomas, with wide variability among the different disease entities. CNS can be affected either at initial diagnosis or at recurrence, and both forms are considered "secondary CNS T-cell lymphoma". Given the low incidence of secondary CNS T-cell lymphoma, related literature is sparse, contradictory, and primarily constituted by small case series and single case reports. However, reported studies uniformly suggest high mortality rates related to this event. Therefore, to improve our ability to identify high-risk patients and offer them successful CNS prophylaxis or timely and effective treatment once the event has occurred may prevent CNS-related T-cell lymphomas deaths. For example, some entities like aggressive adult T-cell leukemia/lymphoma, extranodal natural killer/T-cell lymphoma, and other peripheral T-cell lymphomas with involvement of two or more extranodal organs are prone to CNS dissemination and should be considered for personalized CNS prophylaxis. The level of evidence suggesting an increased risk of CNS recurrence for other T-cell lymphomas and for other risk factors is lower. Published case series show that, following the example of aggressive B-cell lymphomas, patients with T-cell lymphomas and putative increased CNS risk receive different forms of prophylaxis, mostly methotrexate and cytarabine delivered by intrathecal and/or intravenous routes, with varied success. To date, achievements in the treatment of CNS involvement in patients with aggressive B-cell lymphoma were not replicated in secondary CNS T-cell lymphomas, and identification of effective therapies remains an urgent research target. This review is focused on clinical findings, diagnosis, treatment, and prognosis of patients with T-cell lymphoma experiencing CNS dissemination either at presentation or relapse. It aims to provide logical and, oftentimes, evidence-based answers to the most common questions on the most probable risk factors to CNS involvement in patients with T-cell lymphoma, the indications and strategies to prevent this life-threating event, and the management of patients with CNS disease.

Suspected Central Nervous System Infections in HIV-Infected Adults

Objectives: To study the differential diagnosis of HIV-infected patients with suspected central nervous system (CNS) infections and the association of CD4 counts with the final diagnosis. Methods: We analyzed HIV-infected patients from a prospective cohort study on the diagnostic accuracy of clinical and laboratory characteristics in adults with suspected CNS infections in an academic hospital in Amsterdam, the Netherlands, who underwent cerebrospinal fluid (CSF) examination. Results: Thirty-four (9.4%) out of 363 patients with suspected CNS infections were HIV-positive of whom 18 (53%) were diagnosed to have CNS infection, with median CD4 counts of 255 cells/μl. The spectrum of CNS infections consisted of progressive multifocal leukoencephalopathy in three patients (17%); cryptococcal meningoencephalitis, toxoplasma encephalitis, angiostrongylus eosinophilic meningitis, and HIV encephalitis each in two (11%); and cytomegalovirus encephalitis, neurosyphilis, tuberculous meningoencephalitis, histoplasma encephalitis, and varicella-zoster virus meningitis each in one (6%). Clinical characteristics and blood parameters did not differ between HIV-infected patients with CNS infections and other diagnoses. The best predictor for CNS infections was the CSF leukocyte count (AUC = 0.77, 95 CI% 0.61-0.94). The diagnosis of CNS infection was not associated with the CD4 count (median 205 vs. 370, p = 0.21). Two patients (11%) with CNS infections died and two (11%) had neurological sequelae. Conclusions: Half of the patients with suspected CNS infections are diagnosed with a CNS infection, and this was not related to CD4 counts. The best predictor for CNS infections was the CSF leukocyte count.

A comparative study of multimodal magnetic resonance in the differential diagnosis of acquired immune deficiency syndrome related primary central nervous system lymphoma and infection

Background

Patients with acquired immune deficiency syndrome (AIDS) often suffer from opportunistic infections and related primary central nervous system lymphoma (AR-PCNSL). Both diseases showed multiple ring enhancement lesions in conventional magnetic resonance (MR). It is very difficult to make the differential diagnosis. We aimed to investigate whether multimodal MR (diffusion weighted imaging (DWI)/ apparent diffusion coefficient (ADC), 3D pseudo-continuous arterial spin labeling (3D-pCASL) and susceptibility-weighted imaging (SWI)) combined with conventional MR can differentiate AR-PCNSL from infections.

Methods

This was a prospective study. We recruited 19 AIDS patients who were divided into AR-PCNSL group (9 cases) and infection group (10 cases) by pathological results. We analyzed whether there was statistical (Fisher’s method) difference in multimodal MR between the two groups. We analyzed whether multimodal MR combined with conventional MR could improve the diagnosis of AR-PCNSL.

Results

The lesions were more likely involved the paraventricular (0.020) and corpus callosum (0.033) in AR-PCNSL group in conventional MR. In multimodal MR, AR-PCNSL group showed low ADC value, with p values of 0.001. Infection group more inclined to high ADC value, with p was 0.003. In multimodal MR, AR-PCNSL group had more low signal intensity (grade 2–3) in the degree of intratumoral susceptibility signal intensity in SWI (SWI-ITSS), with p values of 0.001. The sensitivity, specificity of conventional MR in the diagnosis of AR-PCNSL was 88.9 and 70.0%. The conventional MR sequence combined with DWI/ADC sequence in the diagnosis of AR-PCNSL had a sensitivity of 100.0%, and a specificity of 60.0%. The sensitivity and specificity of the conventional MR sequence combined with the SWI-ITSS sequence in the diagnosis of AR-PCNSL were 100 and 70.0%. The conventional MR combined with ADC or SWI-ITSS improved the diagnosis of AR-PCNSL.

Conclusion

Multimodal MR could distinguish AR-PCNSL from infectious lesions. The multimodal MR (DWI/ADC or SWI-ITSS) combined with conventional MR could improve the diagnosis of AR-PCNSL. The ADC value should be attached importance in clinical work. When distinguishing AR-PCNSL from toxoplasmosis or tuberculoma, SWI should be used to obtain a correct diagnosis.

Diagnosis, prognosis and treatment of primary central nervous system lymphoma in the elderly population (Review)

Primary central nervous system lymphoma (PCNSL) is a rare subtype of extranodal non-Hodgkin lymphoma that is unique and different from systemic diffuse large B-cell lymphomas. The median age at diagnosis of PCNSL is 65 years and its incidence is rising rapidly in the elderly population. A total of ≥20% of all patients with PCNSL are ≥80 years old. Notably, age has been identified as an independent poor prognostic factor for PCNSL. Elderly patients have an inferior prognosis to that of younger patients and are more severely affected by iatrogenic toxicity; therefore, elderly patients represent a unique and vulnerable treatment subgroup. The present review summarized the available literature to provide an improved understanding of the epidemiology, clinical characteristics, diagnosis, prognosis and management of PCNSL in the elderly population. Notably, the incidence of PCNSL in immunocompetent elderly patients, predominantly in men, is increasing. For the diagnosis of CNSL, imaging-guided stereotactic biopsy is considered the gold standard. When stereotactic biopsy is not possible or conclusive, certain biomarkers have been described that can help establish a diagnosis. PCNSL has a very poor prognosis in the elderly, even though several prognostic scoring systems exist and several prognostic markers have been reported in patients with PCNSL. Furthermore, the treatment of elderly patients remains challenging; it is unlikely that a novel agent could be used as a curative monotherapy; however, a combination of novel agents with polychemotherapy or its combination with other novel drugs may have therapeutic potential.

Serological Responses to Toxoplasma gondii and Matrix Antigen 1 Predict the Risk of Subsequent Toxoplasmic Encephalitis in People Living with HIV

BACKGROUND

Clinically useful predictors for fatal toxoplasmosis are lacking. We investigated the value of serological assays for antibodies to whole Toxoplasma antigens and to peptide antigens of the Toxoplasma cyst protein MAG1, for predicting incident toxoplasmic encephalitis (TE) in people living with HIV (PLWH).

METHODS

We performed a nested case control study, conducted within the Multicenter AIDS Cohort Study (MACS), using serum samples obtained 2 years prior to diagnosis of TE from 28 cases, and 37 HIV disease-matched Toxoplasma seropositive controls at matched time-points. Sera were tested for Toxoplasma antibodies using a commercial assay and for antibodies to MAG1_4.2 and MAG1_5.2 peptides in ELISA.

RESULTS

Two years prior to clinical diagnosis, 68% of TE cases were MAG1_4.2 seropositive compared with 16% of controls (OR 25.0, 95% CI 3.14-199.18). Corresponding results for MAG1_5.2 seropositivity were 36% and 14% (OR 3.6, 95% CI 0.95-13.42). Higher levels of antibody to MAG1_4.2 (OR 18.5 per doubling of the OD value, 95% CI 1.41-242) and to Toxoplasma (OR 2.91 for each OD unit increase, 95% CI 1.48-5.72) were also associated with the risk of TE. When seropositivity was defined as the presence of MAG1 antibody or relatively high levels of Toxoplasma antibody, the sensitivity was 89% and specificity was 68% for subsequent TE.

CONCLUSIONS

Antibodies to MAG1 showed predictive value on the occurrence of TE in PLWH, and the predictive performance was further improved by adding the levels of Toxoplasma antibody. These measures could be clinically useful for predicting subsequent diseases in multiple at-risk populations.

Primary Central Nervous System Lymphomas: A Diagnostic Overview of Key Histomorphologic, Immunophenotypic, and Genetic Features

Primary central nervous system lymphoma (PCNSL) is a rare form of extranodal non-Hodgkin lymphoma that primarily arises in the brain, spinal cord, leptomeninges, and vitreoretinal compartment of the eye. The term is sometimes used interchangeably with primary central nervous system diffuse large B-cell lymphoma (PCNS DLBCL) because DLBCL comprises a great majority (90–95%) of PCNSL. Although rare, other types of lymphomas can be seen in the central nervous system (CNS), and familiarity with these entities will help their recognition and further workup in order to establish the diagnosis. The latter is especially important in the case of PCNSL where procurement of diagnostic specimen is often challenging and yields scant tissue. In this review, we will discuss the most common types of primary lymphomas that can be seen in the CNS with emphasis on the diagnostic histomorphologic, immunophenotypic, and molecular genetic features. The differential diagnostic approach to these cases and potential pitfalls will also be discussed.

Cross-talk between lipid homeostasis and endoplasmic reticulum stress in neurodegeneration: Insights for HIV-1 associated neurocognitive disorders (HAND)

The dysregulation of lipid homeostasis is emerging as a hallmark of many CNS diseases. As aberrant protein regulation is suggested to be a shared pathological feature amongst many neurodegenerative conditions, such as Alzheimer's disease (AD), Parkinson's disease (PD), and Huntington's disease (HD), disruptions in neuronal lipid processing may contribute to disease progression in the CNS. Specifically, given the endoplasmic reticulum (ER) dual role in lipid homeostasis as well as protein quality control (PQC) via unfolded protein response (UPR), lipid dysregulation in the CNS may converge on ER functioning and constitute a crucial mechanism underlying aberrant protein aggregation. In the current review, we discuss the diverse roles of lipid species as essential components of the CNS. Moreover, given the importance of both lipid dysregulation and protein aggregation in pathology of CNS diseases, we attempt to assess the potential downstream cross-talk between lipid dysregulation and ER dependent PQC mechanisms, with special focus on HIV-associated neurodegenerative disorders (HAND).

HIV prevalence in primary central nervous system lymphoma: A systematic review and meta-analysis

HIV infection is considered a major risk factor for primary central nervous system lymphoma (PCNSL). However, the percentage of PCNSL that occurs in HIV + patients is not well defined. We aimed to assess the prevalence of HIV infection in patients with PCNSL through a systematic review and meta-analysis. Electronic databases were searched for studies assessing the presence of HIV infection in series of patients with PCNSL. Pooled prevalence of HIV infection in PCNSL was calculated, with a subgroup analysis based on the geographic area. Twenty-seven studies with 6422 patients were included. Overall, pooled prevalence of HIV infection among PCNSL patients was 6.1 % with high heterogeneity. In the subgroup analysis, pooled prevalence was 3.6 % in India with low heterogeneity, 30.2 % (overall) and 16.5 % (after 2000) in the USA with high heterogeneity, 5.7 % in Europe with high heterogeneity, 2.2 % in East Asia with null heterogeneity, 7.3 % in South America with moderate heterogeneity. In conclusion, only a minor part of PCNSL occurs in patients with HIV. The results stratified by geographic area reflect the different prevalence of HIV infection in the general population, except for India, probably due to the shorter life expectancy of HIV + patients.

Approach to an Intracranial Mass in Patients With HIV

PURPOSE OF REVIEW

Space-occupying lesions represent a diagnostic challenge among people with the human immunodeficiency virus, acquired immunodeficiency syndrome (HIV/AIDS). To determine the best diagnostic approach to the wide array of possible etiologies and provide a thorough interpretation of neuroimaging in order to narrow a hierarchical differential diagnosis among these patients. Given that there is no pathognomonic neuroimaging pattern in this clinical setting, we searched results from brain biopsies to best determine the etiology of commonly found lesions.

RECENT FINDINGS

Multimodal brain MRI and MRI spectroscopy (MRS) often provide the most valuable information in the study of focal masses among people with HIV/AIDS. Brain biopsy appears safe and provides high diagnostic yields in these patients. Among patients with HIV/AIDS who present with space-occupying intracranial lesions, brain MRI and MRS are useful tests. However, in cases of diagnostic uncertainty, brain biopsy is a safe procedure and should be performed. The role of metabolic studies like ²⁰¹Th-SPECT or PET is useful in the detection of primary central nervous system lymphoma.

Excess mortality risk from sepsis in patients with HIV - A meta-analysis

PURPOSE

Differences in HIV prevalence, access to antiretrovirals and ICU resources may result in wide variation in sepsis mortality in HIV patients. The aim of this study was to perform a meta-analysis to quantify the excess risk of sepsis mortality in HIV patients.

MATERIALS AND METHODS

A systematic review was performed using three databases. The systemic inflammatory response syndrome criteria was used for the presumptive diagnosis of sepsis. We only included studies that stratified sepsis mortality by HIV serostatus. A meta-analysis was performed using random effects models, with subgroup analyses performed using country income, sepsis severity, and time periods.

RESULTS

17 studies were included, containing 82,905 patients. Sepsis mortality was found to be 28% higher in the HIV positive patients (95% CI 1.13-1.46, p < .01). Relative risk of mortality was higher in patients treated in low-income countries (RR 1.43 in low-income vs. 1.29 in high-income countries). Mortality was more pronounced in HIV patients with severe sepsis (RR 1.32 in severe sepsis vs. RR 1.15 in sepsis).

CONCLUSIONS

HIV increases the risk of sepsis mortality compared to seronegative individuals across all time periods and geographic areas. We note that this effect is more pronounced in patients with organ dysfunction.

The far-reaching HAND of cART: cART effects on astrocytes

Following the introduction of combination antiretroviral therapy (cART), the morbidity and mortality from human immunodeficiency virus (HIV) infection has been drastically curtailed and HIV has now become a chronic manageable disease. Persons living with HIV (PLWH) are living longer and experiencing significant co-morbidities and conditions of aging. NeuroHIV, clinically defined as HIV-Associated Neurocognitive Disorders (HAND) and pathologically manifested by persistent inflammation in the CNS despite cART, is a significant co-morbid condition for PLWH. In the pre-cART era, HIV mediated much of the pathogenesis in the Central Nervous System (CNS); in the cART era, with low to undetectable viremia, other mechanisms may be contributing to persistent neuroinflammation. Emerging data point to the adverse effects at the cellular level of cART, independent of HIV. Astrocytes are the most abundant cells in the CNS, playing vital roles in maintaining CNS homeostasis (e.g. metabolic support to neurons, clearance of neurotransmitters, ion balance, modulation of synaptic functions and maintaining the structural integrity of the blood brain barrier (BBB). Therefore, any disruption of their function will have wide repercussions in the CNS. In this review, we will address current knowledge and gaps on the impact of antiretrovirals (ARVs) on astrocytes and physiologic consequences in the CNS. Understanding the status of this field, will provide a practical framework to elucidate the potential role of cART-mediated dysregulation of astrocytes in neuroHIV pathogenesis and inform therapeutic strategies that are "neuro-friendly". Graphical abstract CNS-penetrating cART have the potential to cause resting astrocytes to become activated into an A1 or neurotoxic phenotype. These cells can in turn secrete inflammatory cytokines that affect surrounding microglia macrophages, as well as neurotoxic factors that impact nearby neurons. In addition, impairment in the physiologic functions of astrocytes will result in altered BBB permeability and disrupted metabolic homeostasis. CNS=Central Nervous System; cART=combined antiretroviral therapy; BBB=blood brain barrier.

Epstein-Barr Virus Infection in the Development of Neurological Disorders

Epstein-Barr Virus (EBV) is a ubiquitous human herpesvirus that contributes to the etiology of diverse human cancers and auto-immune diseases. EBV establishes a relatively benign, long-term latent infection in over 90 percent of the adult population. Yet, it also increases risk for certain cancers and auto-immune disorders depending on complex viral, host, and environmental factors that are only partly understood. EBV latent infection is found predominantly in memory B-cells, but the natural infection cycle and pathological aberrations enable EBV to infect numerous other cell types, including oral, nasopharyngeal, and gastric epithelia, B-, T-, and NK-lymphoid cells, myocytes, adipocytes, astrocytes, and neurons. EBV infected cells, free virus, and gene products can also be found in the CNS. In addition to the direct effects of EBV on infected cells and tissue, the effect of chronic EBV infection on the immune system is also thought to contribute to pathogenesis, especially auto-immune disease. Here, we review properties of EBV infection that may shed light on its potential pathogenic role in neurological disorders.

Hemostasis in elderly patients with human immunodeficiency virus (HIV) infection-Cross-sectional study

Introduction: Aging and chronic HIV infection are clinical conditions that share the states of inflammation and hypercoagulability. The life expectancy of the world population has increased in the last decades, bringing as complications the occurrence of diseases that undergoing metabolic, bone, cardiological, vascular and neurological alterations. HIV-infected patients experience these changes early and are living longer due to the success of antiretroviral therapy. The objectives of this study was to evaluate some changes in the plasma hemostatic profile of 115 HIV-reactive elderly individuals over 60 years old in the chronic phase of infection, and compare with 88 healthy uninfected elderly individuals. Plasma determinations of D-dimers, Fibrinogen, von Willebrand Factor, Antithrombin, Prothrombin Time, Activated Partial Thromboplastin Time, and platelet count were performed. In the HIV-reactive group, these variables were analyzed according to viral load, protease inhibitor use and CD4⁺ T lymphocyte values. After adjusted values for age and sex, the results showed higher levels of Antithrombin (103%; 88%, p = 0.0001) and Prothrombin Time activities (92.4%; 88.2%, p = 0.019) in the HIV group compared to the control group. We observed higher values of Fibrinogen in protease inhibitor users in both the male (p = 0.043) and female (p = 0.004) groups, and in the female HIV group with detected viral load (p = 0.015). The male HIV group with a CD4⁺ count> 400 cells / mm³ presented higher von Willebrand Factor values (p = 0.036). D-Dimers had higher values in the older age groups (p = 0.003; p = 0.042, respectively). Conclusion: Our results suggest that the elderly with chronic HIV infection with few comorbidities had a better hemostatic profile than negative control group, reflecting the success of treatment. Protease inhibitor use and age punctually altered this profile.

Multiple primary central nervous system lymphoma in the elderly: A case report

RATIONALE

Multiple primary central nervous system lymphoma (MPCNSL) is a rare disease with differential diagnosis and treatment. As the underlying pathogenesis is not yet clarified, the early-stage clinical manifestations are occult and atypical. Also, the imaging manifestations are not specific, which is challenging for the clinical diagnosis and treatment. Therefore, additional clinical research is essential to understand the etiology of the disease.

PATIENT CONCERNS

A 63-year-old male patient suffered from MPCNSLs but without typical clinical manifestations. The findings of the imaging examination were as follows. Magnetic resonance imaging (MRI) showed long T1 and T2 signal shadows in the right frontal lobe, right hippocampus, right cerebellar hemisphere, and the left occipital lobe. In addition, patchy T1-enhanced signal shadows were observed in the right frontal lobe and around the midline. Frontal lesions were detected in the magnetic resonance spectroscopy (MRS), Cho peak increased, and N-acetylaspartate (NAA) peak decreased. On the other hand, in the diffusion weighted imaging (DWI), apparent dispersion coefficient (ADC) showed low-value changes and high signal changes. The positron emission tomography-computed tomography (PET-CT) displayed radioactive accumulation in the right frontal lobe.

DIAGNOSIS

Multiple primary central nervous system lymphoma.

INTERVENTIONS

The patient received some conservative medical treatment, but his condition continued to worsen. Finally, he received a pathological biopsy, and refused further treatment after the result was reported.

OUTCOMES

The patient died 1 week after biopsy, and the course of disease was about 100 days.

LESSONS

PCNSL is a primary intracranial malignancy with low incidence and a high degree of malignancy and specificity in clinical manifestations. To facilitate early clinical treatment and improve the long-term survival of patients, it is necessary to master the imaging diagnostic methods and its features. The comprehensive application of multiple imaging examinations, such as CT, MRI, PET/CT, and PET/MRI, as well as, cerebrospinal fluid cytology can greatly improve the diagnosis of PCNSL.

HIV-1 Tat enhances purinergic P2Y4 receptor signaling to mediate inflammatory cytokine production and neuronal damage via PI3K/Akt and ERK MAPK pathways

Background

HIV-associated neurocognitive disorders (HANDs) afflict more than half of HIV-1-positive individuals. The transactivator of transcription (Tat) produced by HIV virus elicits inflammatory process and is a major neurotoxic mediator that induce neuron damage during HAND pathogenesis. Activated astrocytes are important cells involved in neuroinflammation and neuronal damage. Purinergic receptors expressed in astrocytes participate in a positive feedback loop in virus-induced neurotoxicity. Here, we investigated that whether P2Y4R, a P2Y receptor subtype, that expressed in astrocyte participates in Tat-induced neuronal death in vitro and in vivo.

Methods

Soluble Tat protein was performed to determine the expression of P2Y4R and proinflammatory cytokines in astrocytes using siRNA technique via real-time PCR, Western blot, and immunofluorescence assays. Cytometric bead array was used to measure proinflammatory cytokine release. The TUNEL staining and MTT cell viability assay were analyzed for HT22 cell apoptosis and viability, and the ApopTag® peroxidase in situ apoptosis detection kit and cresyl violet staining for apoptosis and death of hippocampal neuron in vivo.

Results

We found that Tat challenge increased the expression of P2Y4R in astrocytes. P2Y4R signaling in astrocytes was involved in Tat-induced inflammatory cytokine production via PI3K/Akt- and ERK1/2-dependent pathways. Knockdown of P2Y4R expression significantly reduced inflammatory cytokine production and relieved Tat-mediated neuronal apoptosis in vitro. Furthermore, in vivo challenged with Tat, P2Y4R knockdown mice showed decreased inflammation and neuronal damage, especially in hippocampal CA1 region.

Conclusions

Our data provide novel insights into astrocyte-mediated neuron damage during HIV-1 infection and suggest a potential therapeutic target for HANDs.

Electronic supplementary material

The online version of this article (10.1186/s12974-019-1466-8) contains supplementary material, which is available to authorized users.

Primary central nervous system lymphoma in patients with and without HIV infection: a multicenter study and comparison with U.S national data

PURPOSE

Primary central nervous system lymphoma (PCNSL) in patients living with HIV (PLWH) is a distinct entity; however, the management is adopted from patients without HIV. The study aims to examine the differences in presentation, treatment, and outcomes of PCNSL patients with or without HIV.

METHODS

We retrospectively compared the characteristics of 144 patients with PCNSL with and without HIV, and analyzed factors associated with overall and progression-free survival. Results were compared to the Central Brain Tumor Registry of the United States (CBTRUS) and the National Cancer Institute's Surveillance, Epidemiology, and End Results (SEER) system.

RESULTS

Among all patients with PCNSL, 19% had HIV. PLWH were younger (38 vs. 63 years; p < 0.01) and more likely to be African American (59% vs. 7%; p < 0.01) and male (74% vs. 49%; p = 0.02) than patients without HIV. PLWH were more likely to have multiple lesions (67% vs. 43%; p = 0.02), hemorrhage (59 vs. 37%; p = 0.03), and peripheral rim enhancement (57% vs. 7%; p < 0.01) on imaging; to receive palliative care (15% vs. 2%) or whole brain radiation (63% vs. 3%); and less likely to receive chemotherapy (22% vs. 95%) (p < 0.01). Twenty-four patients, none PLWH, underwent stem cell transplant. Not receiving transplant was an independent factor in mortality and disease progression. Our cohort of patients, compared to the national database, were younger (60 vs. 65 years), 58% were white vs. 75%, and had longer median overall survival 43 vs. 25 months.

CONCLUSION

Epidemiology, imaging, and treatment options for patients with PCNSL with and without HIV differ, but HIV was not an independent factor of mortality or disease progression. More efforts are needed to improve access to research and treatment options for PLWH with PCNSL.

Effective in Vivo Targeting of Influenza Virus through a Cell-Penetrating/Fusion Inhibitor Tandem Peptide Anchored to the Plasma Membrane

The impact of influenza virus infection is felt each year on a global scale when approximately 5-10% of adults and 20-30% of children globally are infected. While vaccination is the primary strategy for influenza prevention, there are a number of likely scenarios for which vaccination is inadequate, making the development of effective antiviral agents of utmost importance. Anti-influenza treatments with innovative mechanisms of action are critical in the face of emerging viral resistance to the existing drugs. These new antiviral agents are urgently needed to address future epidemic (or pandemic) influenza and are critical for the immune-compromised cohort who cannot be vaccinated. We have previously shown that lipid tagged peptides derived from the C-terminal region of influenza hemagglutinin (HA) were effective influenza fusion inhibitors. In this study, we modified the influenza fusion inhibitors by adding a cell penetrating peptide sequence to promote intracellular targeting. These fusion-inhibiting peptides self-assemble into ∼15-30 nm nanoparticles (NPs), target relevant infectious tissues in vivo, and reduce viral infectivity upon interaction with the cell membrane. Overall, our data show that the CPP and the lipid moiety are both required for efficient biodistribution, fusion inhibition, and efficacy in vivo.

The role of brain biopsy in the clinical management of HIV-related focal brain lesions

OBJECTIVES

Up to 20% of HIV-related focal brain lesion (FBL) diagnoses cannot be determined without invasive procedures. In such cases, brain biopsy is an important step in the evaluation algorithm. The aims of this study were to describe the clinical outcomes of patients with FBL, the proportion of diagnoses confirmed by brain biopsies and their aetiologies, and to analyse the proportion of patients in whom the biopsy motivated a change in therapeutic management.

METHODS

A retrospective cohort study was performed. The data from clinical records of patients with HIV-related FBL admitted between January 2005 and December 2015 were reviewed.

RESULTS

A total of 137 patients were included in the study. The median age was 39 years [interquartile range (IQR) 33-44.5 years]. The median CD4 count was 54 cells/μL (IQR 21-124 cells/μL). Cerebral brain biopsy was performed in 21.16% of patients (29 of 137); 68.9% of these individuals (20 of 29) were diagnosed by histology, with results of central nervous system (CNS) lymphoma in 20.6% (six of 29), progressive multifocal leucoencephalopathy in 6.8% (two of 29), toxoplasmosis in 6.8% (two of 29), tuberculoma in 6.8% (two of 29), and other diagnoses in 27.6% (eight of 29). In nine patients, the histology was nonspecific. In 75.8% of patients (22 of 29), the result of the biopsy led to a change in the therapeutic management. We did not observe higher rates of mortality related to the procedure. Overall mortality at 30 and 90 days was similar in patients who were and were not biopsied.

CONCLUSIONS

In this retrospective cohort study, cerebral biopsy was associated with significant adjustments in therapeutic management for a high percentage of patients.

Methamphetamine increases HIV infectivity in neural progenitor cells

HIV-1 infection and methamphetamine (METH) abuse frequently occur simultaneously and may have synergistic pathological effects. Although HIV-positive/active METH users have been shown to have higher HIV viral loads and experience more severe neurological complications than non-users, the direct impact of METH on HIV infection and its link to the development of neurocognitive alternations are still poorly understood. In the present study, we hypothesized that METH impacts HIV infection of neural progenitor cells (NPCs) by a mechanism encompassing NFκB/SP1-mediated HIV LTR activation. Mouse and human NPCs were infected with EcoHIV (modified HIV virus infectious to mice) and HIV, respectively, in the presence or absence of METH (50 or 100 μm). Pretreatment with METH, but not simultaneous exposure, significantly increased HIV production in both mouse and human NPCs. To determine the mechanisms underlying these effects, cells were transfected with different variants of HIV LTR promoters and then exposed to METH. METH treatment induced transcriptional activity of the HIV LTR promotor, an effect that required both NFκB and SP1 signaling. Pretreatment with METH also decreased neuronal differentiation of HIV-infected NPCs in both in vitro and in vivo settings. Importantly, NPC-derived daughter cells appeared to be latently infected with HIV. This study indicates that METH increases HIV infectivity of NPCs, through the NFκB/SP1-dependent activation of the HIV LTR and with the subsequent alterations of NPC neurogenesis. Such events may underlie METH- exacerbated neurocognitive dysfunction in HIV-infected patients.

Cerebrospinal fluid biomarkers of malignancies located in the central nervous system

CNS malignancies include primary tumors that originate within the CNS as well as secondary tumors that develop as a result of metastatic cancer. The delicate nature of the nervous systems makes tumors located in the CNS notoriously difficult to reach, which poses several problems during diagnosis and treatment. CSF can be acquired relatively easy through lumbar puncture and offers an important compartment for analysis of cells and molecules that carry information about the malignant process. Such techniques have opened up a new field of research focused on the identification of specific biomarkers for several types of CNS malignancies, which may help in diagnosis and monitoring of tumor progression or treatment response. Biomarkers are sought in DNA, (micro)RNA, proteins, exosomes and circulating tumor cells in the CSF. Techniques are rapidly progressing to assess these markers with increasing sensitivity and specificity, and correlations with clinical parameters are being investigated. It is expected that these efforts will, in the near future, yield clinically relevant markers that aid in diagnosis, monitoring and (tailored) treatment of patients bearing CNS tumors. This chapter provides a summary of the current state of affairs of the field of biomarkers of different types of CNS tumors.

HIV-1-associated inflammation and antiretroviral therapy regulate astrocyte endoplasmic reticulum stress responses

Antiretroviral (ARV) therapy (ART) has effectively suppressed the incidence of human immunodeficiency virus (HIV)-associated dementia in HIV-1 positive individuals. However, the prevalence of more subtle forms of neurocognitive dysfunction continues to escalate. Recently, endoplasmic reticulum (ER) stress has been linked to many neurological diseases; yet, its role in HIV/neuroAIDS remains largely unexplored. Furthermore, upregulation of astrocyte elevated gene-1 (AEG-1), a novel HIV-1 inducible gene, along with ER stress markers in a Huntington’s disease model, suggests a possible role in HIV-associated ER stress. The current study is focused on unfolded protein responses (UPRs) and AEG-1 regulation in primary human astrocytes exposed to HIV-associated neurocognitive disorders (HAND)-relevant stimuli (HIV-1 virions, inflammation and ARV drugs). Interleukin (IL)-1β and the nucleoside reverse transcriptase inhibitor abacavir upregulated expression of ER stress markers in human astrocytes, including binding immunoglobulin protein (BiP), C/EBP homologous protein (CHOP), and calnexin. In addition, IL-1β activated all three well-known UPR pathways: protein kinase RNA-like ER kinase (PERK); activating transcription factor 6 (ATF-6); and inositol-requiring enzyme 1α (IRE1α). AEG-1 upregulation correlated to ER stress and demonstrated astrocyte AEG-1 interaction with the calcium-binding chaperone, calnexin. IL-1β and abacavir enhanced intracellular calcium signaling in astrocytes in the absence of extracellular calcium, illustrating ER-associated calcium release. Alternatively, calcium evoked in response to HAND-relevant stimuli led to mitochondrial permeability transition pore (mPTP) opening in human astrocytes. Importantly, IL-1β- and abacavir-induced UPR and mPTP opening were inhibited by the intracellular calcium chelation, indicating the critical role of calcium signaling in HAND-relevant ER stress in astrocytes. In summary, our study highlights that ARV drugs and IL-1β induced UPR, AEG-1 expression, intracellular calcium, and mitochondrial depolarization in astrocytes. This study uncovers astrocyte ER stress as a novel therapeutic target in the management of HIV-1-associated neurotoxicity and possibly in the treatment of neuroAIDS.

Pyogenic Brain Abscess Caused by Peptostreptococcus in a Patient with HIV-1 Infection

In the setting of HIV, cerebral lesions are usually secondary to lymphoma and opportunistic infections; however, in patients with CD4 counts above 200 cells/uL, other pathologies such as pyogenic brain abscess could gain importance. The microbiology of pyogenic brain abscess has Staphylococcus and Streptococcus as the leading etiologic pathogens in immunocompetent individuals. Peptostreptococcus is also recognized as a common cause of brain abscess in this patient population. In HIV-infected individuals, there have been sporadic reports of Peptostreptococcus infections but none of brain abscess. We describe the case of a 43-years-old HIV-infected patient with a CD4 count of 350 cells/uL that developed a Peptostreptococcus brain abscess presumably from hematogenous spread of an odontogenic source. Treatment with stereotactic needle aspiration in two opportunities and four weeks of intravenous antibiotics led to a complete resolution of this infection. This case highlights the importance of a multidisciplinary approach for an effective treatment of pyogenic brain abscess in HIV-1 patients.

Incidence of Neurological Disorders Among HIV-Infected Individuals With Universal Health Care in Taiwan From 2000 to 2010

OBJECTIVE

To determine the incidence of and factors associated with neurological disorders in a large Taiwanese cohort of HIV-infected persons with free access to highly active antiretroviral therapy (HAART).

DESIGN

A retrospective population-based cohort study was conducted using the National Health Insurance Research Database for the years 2000-2010.

METHODS

We identified 13,316 HIV-positive persons from 2000 through 2010. We used direct standardization to calculate age-adjusted and sex-adjusted incidence rates based on the 2000 World Health Organization world standard population. Factors associated with neurological disorders were analyzed using a Cox proportional hazards model.

RESULTS

The standardized incidence of neurological disorders among HIV-infected persons increased from 22.16 per 1000 person-years in 2000 to 25.23 per 1000 person-years in 2010. Cognitive disorders increased significantly from 0.36 per 1000 person-years in 2001 to 7.44 per 1000 person-years in 2010 (trend P < 0.001). The rate of neurological disorders increased with age ≥55 years [adjusted hazard ratios (AHRs) 2.54, 95% confidence interval (CI): 1.89 to 3.40], hypertension (AHR 1.41, 95% CI: 1.12 to 1.76), substance abuse (AHR 1.65, 95% CI: 1.36 to 2.02), opportunistic infection (AHR 1.76, 95% CI: 1.47 to 2.11), syphilis (AHR 1.27, 95% CI: 1.10 to 1.47), and emergency department visits >5 (AHR 2.41, 95% CI: 1.96 to 2.97). The incidence of neurological disorders was negatively associated with adherence to HAART (adherence ≥85% AHR: 0.79, 95% CI: 0.64 to 0.97).

CONCLUSIONS

The rising incidence of cognitive disorders among HIV-positive persons highlights the need to provide routine neurological evaluations at clinical visits. Receiving HAART with adherence ≥85% contributes to a reduced risk of neurological disorders.

Multiple cause-of-death data among people with AIDS in Italy: a nationwide cross-sectional study

Background

Multiple cause-of-death (MCOD) data allow analyzing the contribution to mortality of conditions reported on the death certificate that are not selected as the underlying cause of death. Using MCOD data, this study aimed to fully describe the cause-specific mortality of people with AIDS (PWA) compared to people without AIDS.

Methods

We conducted a nationwide investigation based on death certificates of 2,515 Italian PWA and 123,224 people without AIDS who had died between 2006 and 2010. The conditions most frequently associated with PWA mortality, compared to people without AIDS, were identified using an age-standardized proportion ratio (ASPR) calculated as the ratio between the age-standardized proportion of a specific cause among PWA and the same proportion among people without AIDS.

Results

The most frequently reported conditions at death among PWA were infectious/parasitic diseases (52%), digestive (36%), respiratory (33%), and circulatory (32%) system diseases, and neoplasms (29%). All AIDS-defining conditions resulted highly associated (ASPR significantly greater than unity) with PWA deaths. Significant associations also emerged for leishmaniasis (ASPR = 188.0), encephalitis/myelitis/encephalomyelitis (ASPR = 14.3), dementia (ASPR = 13.1), chronic viral hepatitis (ASPR = 13.1), liver fibrosis/cirrhosis (ASPR = 4.4), pneumonia (ASPR = 4.4), anal (ASPR = 12.1) and liver (ASPR = 1.9) cancers, and Hodgkin’s disease (ASPR = 3.1).

Conclusions

Study findings identified the contribution of several non-AIDS-defining conditions on PWA mortality, emphasizing the need of preventive public health interventions targeting this population.

Toxoplasmosis with chorioretinitis in an HIV-infected child with no visual complaints-importance of fundus examination

Central nervous system lesions are common in HIV-infected patients. In the combination anti-retroviral therapy (ART) era, Toxoplasma reactivation has been observed only in patients with unrecognized HIV infection or refusing therapy. We present the case of 10-year-old girl with AIDS who initially presented with pneumonia. She was treated for pneumonia and thereafter started on ART as her CD4 count was low. However, 5 days after starting ART she presented with left ptosis and right-sided monoparesis. She was diagnosed with neurotoxoplasmosis and responded successfully to pyrimethamine–sulfadoxine therapy. Though she had no vision difficulties, her fundus examination revealed chorioretinitis during the hospital stay. We emphasize the importance of routine fundus examination prior to starting ART to rule out chorioretinitis even in an older child with no visual complaints.

Toxoplasmosis versus lymphoma: Cerebral lesion characterization using DSC-MRI revisited

OBJECTIVE

CNS toxoplasmosis and lymphoma are often indistinguishable by conventional contrast-enhanced MRI. There is limited literature on the diagnostic efficacy of dynamic susceptibility contrast (DSC) MRI for differentiating these entities. This study assesses the clinical utility of relative cerebral blood volume (rCBV) for making a diagnosis and determines rCBV thresholds for differentiation using contemporary DSC-MRI.

PATIENTS AND METHODS

Thirteen patients with 25 lesions (13 toxoplasmosis and 12 lymphoma) and pre-treatment DSC-MRI were identified retrospectively. Volumetric regions of interest of segmented enhancement were used to extract mean rCBV normalized to normal-appearing white matter for each lesion. We compared average mean rCBV between all toxoplasmosis and lymphoma lesions using a general mixed model. Three models were also compared for evaluating rCBV-based disease status in each patient: 1) mean rCBV of each lesion using a generalized estimating equation, 2) volume-weighted mean rCBV, and 3) maximum mean rCBV of all lesions using logistic regression.

RESULTS

The average mean rCBV for all toxoplasmosis lesions was 0.98 (95% CI 0.55-1.41) compared to 2.07 (95% CI 1.71-2.43) for all lymphoma lesions, a significant difference (1.09, 95% CI 0.53-1.65, p=0.0013). For the three models used to evaluate rCBV-based disease status in each patient, a significant relationship was observed, with an optimal rCBV threshold of approximately 1.5 for distinguishing lymphoma from toxoplasmosis in each model.

CONCLUSION

RCBV derived from contemporary DSC-MRI is helpful for distinguishing between cerebral toxoplasmosis and cerebral lymphoma on an individual patient basis and may facilitate more timely initiation of appropriate directed therapy.

Adolescent and young adult non-Hodgkin lymphoma

Non-Hodgkin lymphoma (NHL) is a heterogeneous group of lymphoid malignancies accounting for a significant portion of cancers occurring in children, adolescents and young adults with an increasing incidence with age. The adolescent and young adult (AYA) population presents a specific set of characteristics and challenges. The most common diseases occurring in adolescents and young adults include Burkitt lymphoma, lymphoblastic lymphoma, diffuse large B-cell lymphoma, anaplastic large cell lymphoma and primary mediastinal B-cell lymphoma. There is also a higher incidence of primary central nervous system lymphoma in AYA patients. Cure rates largely depend on risk-stratification, and are generally superior to outcomes in comparison to older adult data but less than in younger children. Here, we review the unique clinical and biological characteristics of NHL occurring in the AYA population with a focus on how to achieve similar curative outcomes in AYA that have been established in younger cohorts.

Brain Invasion by CD4(+) T Cells Infected with a Transmitted/Founder HIV-1BJZS7 During Acute Stage in Humanized Mice

Human immunodeficiency virus (HIV)-associated neurocognitive disorder (HAND) is one of the common causes of cognitive dysfunction and morbidity among infected patients. However, to date, it remains unknown if a transmitted/founder (T/F) HIV-1 leads to neurological disorders during acute phase of infection. Since it is impossible to answer this question in humans, we studied NOD.Cg-Prkdc scid Il2rgtm1Wjl/SzJ mice (NSG) reconstituted with human PBMC (NSG-HuPBL), followed by the peritoneal challenge with the chronic HIV-1JR-FL and the T/F HIV-1BJZS7, respectively. By measuring viral load, P24 antigenemia and P24(+) cells in peripheral blood and various tissue compartments, we found that systemic infections were rapidly established in NSG-HuPBL mice by both HIV-1 strains. Although comparable peripheral viral loads were detected during acute infection, the T/F virus appeared to cause less CD4(+) T cell loss and less numbers of infected cells in different organs and tissue compartments. Both viruses, however, invaded brains with P24(+)/CD3(+) T cells detected primarily in meninges, cerebral cortex and perivascular areas. Critically, brain infections with HIV-1JR-FL but not with HIV-1BJZS7 resulted in damaged neurons together with activated microgliosis and astrocytosis as determined by significantly increased numbers of Iba1(+) microglial cells and GFAP(+) astrocytes, respectively. The increased Iba1(+) microglia was correlated positively with levels of P24 antigenemia and negatively with numbers of NeuN(+) neurons in brains of infected animals. Our findings, therefore, indicate the establishment of two useful NSG-HuPBL models, which may facilitate future investigation of mechanisms underlying HIV-1-induced microgliosis and astrocytosis.

HIV-1, methamphetamine and astrocytes at neuroinflammatory Crossroads

As a popular psychostimulant, methamphetamine (METH) use leads to long-lasting, strong euphoric effects. While METH abuse is common in the general population, between 10 and 15% of human immunodeficiency virus-1 (HIV-1) patients report having abused METH. METH exacerbates the severity and onset of HIV-1-associated neurocognitive disorders (HAND) through direct and indirect mechanisms. Repetitive METH use impedes adherence to antiretroviral drug regimens, increasing the likelihood of HIV-1 disease progression toward AIDS. METH exposure also directly affects both innate and adaptive immunity, altering lymphocyte numbers and activity, cytokine signaling, phagocytic function and infiltration through the blood brain barrier. Further, METH triggers the dopamine reward pathway and leads to impaired neuronal activity and direct toxicity. Concurrently, METH and HIV-1 alter the neuroimmune balance and induce neuroinflammation, which modulates a wide range of brain functions including neuronal signaling and activity, glial activation, viral infection, oxidative stress, and excitotoxicity. Pathologically, reactive gliosis is a hallmark of both HIV-1- and METH-associated neuroinflammation. Significant commonality exists in the neurotoxic mechanisms for both METH and HAND; however, the pathways dysregulated in astroglia during METH exposure are less clear. Thus, this review highlights alterations in astrocyte intracellular signaling pathways, gene expression and function during METH and HIV-1 comorbidity, with special emphasis on HAND-associated neuroinflammation. Importantly, this review carefully evaluates interventions targeting astrocytes in HAND and METH as potential novel therapeutic approaches. This comprehensive overview indicates, without a doubt, that during HIV-1 infection and METH abuse, a complex dialog between all neural cells is orchestrated through astrocyte regulated neuroinflammation.