Neurosarcoidosis of the trigeminal nerve: clinical accompaniments, radiographic findings, and association with neuralgia.

BACKGROUND: Cranial neuropathy is a principal disease manifestation of neurosarcoidosis, but many forms remain poorly described, including trigeminal nerve disease despite its frequency in reported cohorts (5-12%). Herein, we characterize the clinical course of patients with neurosarcoidosis involving the trigeminal nerve. METHODS: A single-center retrospective cohort analysis of patients with biopsy-proven sarcoidosis involving the trigeminal nerve was conducted between 1/1/2000-3/7/2023. RESULTS: The trigeminal nerve was affected in 14/245 (5.7%) patients, being clinically symptomatic in 5/245 (2.0%) and asymptomatic with radiographic involvement in 9/245 (3.7%). 14/14 (100.0%) patients had systemic sarcoidosis. In the symptomatic group, trigeminal neuropathy was an inaugural feature in 4/5 (80.0%), unilateral in 5/5 (100.0%) with the V1 subdivision most affected (4/5, 80.0%), and associated with neuralgia in 2/5 (40.0%). On MRI, the cisternal nerve roots (9/14, 64.3%), Meckel's cave (7/14, 50.0%), and cavernous sinus (5/14, 35.7%) were most commonly affected, and 14/14 (100.0%) patients had extra-trigeminal neuroinflammation on cranial MRI. CSF was abnormal in at least one dimension in 11/12 (91.7%) tested. All three treated patients with symptomatic trigeminal neuropathy responded to immunomodulatory treatment, and symptomatic treatments for trigeminal neuralgia were helpful in two patients. After a median follow-up period of 63 months, the median modified Rankin scale score was 1 for both subgroups. CONCLUSION: Neurosarcoidosis may involve any portion of the trigeminal apparatus, and when affected, it frequently demonstrates a mismatch in radiographic involvement from its clinical manifestations of facial numbness and pain, and typically occurs in association with other clinical or radiographic manifestations of neurosarcoidosis.

The identification of intact HIV proviral DNA from human cerebrospinal fluid.

We evaluated the HIV-1 DNA reservoir in peripheral blood mononuclear cells (PBMC) and cerebrospinal fluid (CSF) in people with HIV (PWH) and associations to cognitive dysfunction. Using the intact proviral DNA assay (IPDA), an emerging technique to identify provirus that may be the source of viral rebound, we assessed HIV DNA in CSF and PBMC in PWH regardless of antiretroviral therapy (ART). CSF was used as a sampling surrogate for the central nervous system (CNS) as opposed to tissue. IDPA results (3' defective, 5' defective, and intact HIV DNA) were analyzed by compartment (Wilcoxon signed rank; matched and unmatched pairs). Cognitive performance, measured via a battery of nine neuropsychological (NP) tests, were analyzed for correlation to HIV DNA (Spearman's rho). 11 CSF and 8 PBMC samples from PWH were evaluated both unmatched and matched. Total CSF HIV DNA was detectable in all participants and was significantly higher than in matched PBMCs (p â€‹= â€‹0.0039). Intact CSF HIV DNA was detected in 7/11 participants and correlated closely with those in PBMCs but tended to be higher in CSF than in PBMC. CSF HIV DNA did not correlate with global NP performance, but higher values did correlate with worse executive function (p â€‹= â€‹0.0440). Intact HIV DNA is frequently present in the CSF of PWH regardless of ART. This further supports the presence of an HIV CNS reservoir and provides a method to study CNS reservoirs during HIV cure studies. Larger studies are needed to evaluate relationships with CNS clinical outcomes.

Exploration of potential immune mechanisms in cervical dystonia.

BACKGROUND: Although there are many possible causes for cervical dystonia (CD), a specific etiology cannot be identified in most cases. Prior studies have suggested a relationship between autoimmune disease and some cases of CD, pointing to possible immunological mechanisms. OBJECTIVE: The goal was to explore the potential role of multiple different immunological mechanisms in CD. METHODS: First, a broad screening test compared neuronal antibodies in controls and CD. Second, unbiased blood plasma proteomics provided a broad screen for potential biologic differences between controls and CD. Third, a multiplex immunoassay compared 37 markers associated with immunological processes in controls and CD. Fourth, relative immune cell frequencies were investigated in blood samples of controls and CD. Finally, sequencing studies investigated the association of HLA DQB1 and DRB1 alleles in controls versus CD. RESULTS: Screens for anti-neuronal antibodies did not reveal any obvious abnormalities. Plasma proteomics pointed towards certain abnormalities of immune mechanisms, and the multiplex assay pointed more specifically towards abnormalities in T lymphocytes. Abnormal immune cell frequencies were identified for some CD cases, and these cases clustered together as a potential subgroup. Studies of HLA alleles indicated a possible association between CD and DRB1*15:03, which is reported to mediate the penetrance of autoimmune disorders. CONCLUSIONS: Altogether, the association of CD with multiple different blood-based immune measures point to abnormalities in cell-mediated immunity that may play a pathogenic role for a subgroup of individuals with CD.

Honokiol hexafluoro confers reversal of neuropathological markers of HIV infection in a murine SCID model.

Cognitive impairment remains a persistent challenge in people living with HIV (PWLH) despite antiretroviral therapy (ART) due to ART's inability to eliminate brain HIV. HIV-induced cognitive dysfunction results from immune dysregulation, ongoing neuroinflammation, and the continuous virus presence, collectively contributing to cognitive deficits. Therefore, adjunctive therapies are needed to reduce cerebral HIV reservoirs, mitigate neuroinflammation, and impede cognitive dysfunction progression. Our study focused on Honokiol, known for its anti-inflammatory and neuroprotective properties, in an experimental mouse model simulating HIV-induced cognitive dysfunction. Using Honokiol Hexafluoro (HH), a synthetic analogue, we comprehensively evaluated its potential to ameliorate cognitive dysfunction and cerebral pathology in HIV-associated cognitive dysfunction. Our findings showed that HH treatment effectively reversed HIV-induced cognitive dysfunction, concurrently suppressing astrocyte activation, restoring neuronal dendritic arborization, and reducing microglial activation. Furthermore, HH remodeled the metabolic profile of HIV-infected human monocyte-derived macrophages, resulting in decreased activation and the promotion of a quiescent state in vitro.

A Rationale and Approach to the Development of Specific Treatments for HIV Associated Neurocognitive Impairment.

Neurocognitive impairment (NCI) associated with HIV infection of the brain impacts a large proportion of people with HIV (PWH) regardless of antiretroviral therapy (ART). While the number of PWH and severe NCI has dropped considerably with the introduction of ART, the sole use of ART is not sufficient to prevent or arrest NCI in many PWH. As the HIV field continues to investigate cure strategies, adjunctive therapies are greatly needed. HIV imaging, cerebrospinal fluid, and pathological studies point to the presence of continual inflammation, and the presence of HIV RNA, DNA, and proteins in the brain despite ART. Clinical trials exploring potential adjunctive therapeutics for the treatment of HIV NCI over the last few decades have had limited success. Ideally, future research and development of novel compounds need to address both the HIV replication and neuroinflammation associated with HIV infection in the brain. Brain mononuclear phagocytes (MPs) are the primary instigators of inflammation and HIV protein expression; therefore, adjunctive treatments that act on MPs, such as immunomodulating agents, look promising. In this review, we will highlight recent developments of innovative therapies and discuss future approaches for HIV NCI treatment.

Neurological Complications in Children Hospitalized With Seizures and Respiratory Infections: A Comparison Between SARS-CoV-2 and Other Respiratory Infections.

BACKGROUND: Children with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection can experience neurological symptoms, but limited data are available on neurological symptoms associated with other respiratory infections. We compared proportions of neurological symptoms in children hospitalized with seizures and respiratory infections, including SARS-CoV-2, influenza, and endemic coronaviruses. METHODS: A retrospective cohort study was performed on children admitted for seizures who had positive respiratory polymerase chain reactions for SARS-CoV-2, coronavirus NL63, coronavirus OC34, influenza (A and B), adenovirus, Mycoplasma pneumoniae, or parainfluenza 3 or 4. Primary outcomes were rates of new neurological diagnoses and mortality. RESULTS: A total of 883 children were included. Mortality rates ranged from 0% with M. pneumoniae to 4.9% with parainfluenza 4. Strokes were observed with all infections except for coronavirus OC43 and M. pneumoniae, with the highest rates in parainfluenza 4 (4.9%) and SARS-CoV-2 (5.9%). Compared with other infections, children with SARS-CoV-2 were older, had higher rates of stroke, and lower rates of intubation. The most common brain magnetic resonance imaging (MRI) abnormality was diffusion restriction. Abnormal MRI rates were lower in SARS-CoV-2, compared with patients with other coronavirus (OC). However, rates of stroke, encephalopathy, hypoxic-ischemic encephalopathy, and meningoencephalitis were similar between SARS-CoV-2 and influenza cohorts. CONCLUSIONS: In children hospitalized with seizures, higher rates of stroke were observed in SARS-CoV-2 versus OC. Similar rates of neurological symptoms were observed in patients with SARS-CoV-2 and those with influenza. Strokes can occur in children with these viral infections, particularly SARS-CoV-2.

Immune responses to SARS-CoV-2 vaccination in multiple sclerosis: a systematic review/meta-analysis.

INTRODUCTION: Responses to SARS-CoV-2 vaccination in patients with MS (pwMS) varies by disease-modifying therapies (DMTs). We perform a meta-analysis and systematic review of immune response to SARS-CoV-2 vaccines in pwMS. METHODS: Two independent reviewers searched PubMed, Google Scholar, and Embase from January 1, 2019-December 31, 2021, excluding prior SARS-CoV-2 infections. The meta-analysis of observational studies in epidemiology (MOOSE) guidelines were applied. The data were pooled using a fixed-effects model. RESULTS: Eight-hundred sixty-four healthy controls and 2203 pwMS from 31 studies were included. Antibodies were detected in 93% healthy controls (HCs), and 77% pwMS, with >93% responses in all DMTs (interferon-beta, glatiramer acetate, cladribine, natalizumab, dimethyl fumarate, alemtuzumab, and teriflunomide) except for 72% sphingosine-1-phosphate modulators (S1PM) and 44% anti-CD20 monoclonal antibodies (mAbs). T-cell responses were detected in most anti-CD20 and decreased in S1PM. Higher antibody response was observed in mRNA vaccines (99.7% HCs) versus non-mRNA vaccines (HCs: 72% inactivated virus; pwMS: 86% vector, 59% inactivated virus). A multivariate logistic regression model to predict vaccine response demonstrated that mRNA versus non-mRNA vaccines had a 3.4 odds ratio (OR) for developing immunity in anti-CD20 (p = 0.0052) and 7.9 OR in pwMS on S1PM or CD20 mAbs (p < 0.0001). Antibody testing timing did not affect antibody detection. CONCLUSION: Antibody responses are decreased in S1PM and anti-CD20; however, cellular responses were positive in most anti-CD20 with decreased T cell responses in S1PM. mRNA vaccines had increased seroconversion rates compared to non-RNA vaccines. Further investigation in how DMTs affect vaccine immunity are needed.

Novel method to quantify phenotypic markers of HIV-associated neurocognitive disorder in a murine SCID model.

Despite combined antiretroviral therapy (cART), HIV infection in the CNS persists with reported increases in activation of macrophages (MΦ), microglia, and surrounding astrocytes/neurons, conferring HIV-induced inflammation. Chronic inflammation results in HIV-associated neurocognitive disorders (HAND) with reported occurrence of up to half of individuals with HIV infection. The existing HAND mouse model used by laboratories including ours, and the effect of novel agents on its pathology present with labor-intensive and time-consuming limitations since brain sections and immunohistochemistry assays have to be performed and analyzed. A novel flow cytometry-based system to objectively quantify phenotypic effects of HIV using a SCID mouse HAND model was developed which demonstrated that the HIV-infected mice had significant increases in astrogliosis, loss of neuronal dendritic marker, activation of murine microglia, and human macrophage explants compared to uninfected control mice. HIV p24 could also be quantified in the brains of the infected mice. Correlation of these impairments with HIV-induced brain inflammation and previous behavioral abnormalities studies in mice suggests that this model can be used as a fast and relevant throughput methodology to quantify preclinical testing of novel treatments for HAND.

HIV X4 Variants Increase Arachidonate 5-Lipoxygenase in the Pulmonary Microenvironment and are associated with Pulmonary Arterial Hypertension.

Pulmonary Arterial Hypertension (PAH) is overrepresented in People Living with Human Immunodeficiency Virus (PLWH). HIV protein gp120 plays a key role in the pathogenesis of HIV-PAH. Genetic changes in HIV gp120 determine viral interactions with chemokine receptors; specifically, HIV-X4 viruses interact with CXCR4 while HIV-R5 interact with CCR5 co-receptors. Herein, we leveraged banked samples from patients enrolled in the NIH Lung HIV studies and used bioinformatic analyses to investigate whether signature sequences in HIV-gp120 that predict tropism also predict PAH. Further biological assays were conducted in pulmonary endothelial cells in vitro and in HIV-transgenic rats. We found that significantly more persons living with HIV-PAH harbor HIV-X4 variants. Multiple HIV models showed that recombinant gp120-X4 as well as infectious HIV-X4 remarkably increase arachidonate 5-lipoxygenase (ALOX5) expression. ALOX5 is essential for the production of leukotrienes; we confirmed that leukotriene levels are increased in bronchoalveolar lavage fluid of HIV-infected patients. This is the first report associating HIV-gp120 genotype to a pulmonary disease phenotype, as we uncovered X4 viruses as potential agents in the pathophysiology of HIV-PAH. Altogether, our results allude to the supplementation of antiretroviral therapy with ALOX5 antagonists to rescue patients with HIV-X4 variants from fatal PAH.

Development and Validation of the Rasch-Built Overall Amyotrophic Lateral Sclerosis Disability Scale (ROADS).

Importance: A new outcome measure for overall disability level with improved responsiveness is needed for amyotrophic lateral sclerosis (ALS) clinical trials. Objective: To describe the creation and development of a new self-reported ALS disability scale with improved item targeting and psychometric properties that used a mathematically rigorous Rasch methodology. Design, Setting, and Participants: A preliminary ALS disability questionnaire with 119 questions was created based on literature review, clinical judgement of an expert panel, and patient input. Patients with ALS were recruited from January 2017 to June 2019 from the Emory University and Atlanta VA Medical Center ALS clinics, both in Atlanta, Georgia, during regularly scheduled clinic appointments to complete the draft questionnaire and standard ALS outcome measures. All consecutive patients seen at the Emory University and Atlanta VA Medical Center ALS clinics during the recruitment period with a diagnosis of ALS who were able to provide informed consent were invited to participate in the study. Rasch analyses were performed, and items were systematically removed based on missing data, model fit, disordered thresholds, item bias, and clinical judgment. A total of 509 patients with ALS were seen at the 2 sites during the recruitment period, and 264 patients provided informed consent. Interventions: Participants completed the draft Rasch questionnaire and the revised Amyotrophic Lateral Sclerosis Functional Rating Scale (ALSFRS-R). Main Outcomes and Measures: Rasch analyses and standard scale metrics were performed to create the new scale, and Rasch analyses were performed on the ALSFRS-R for comparison. Results: Overall, 243 participants with ALS completed the draft questionnaire, and 230 participants were included for Rasch analyses. The mean (SD) age for study participants was 61.9 (11.1) years, 146 (60.1%) were men, and site of onset was 23.0% bulbar (n = 56), 36.2% upper extremity (n = 88), and 39.5% lower extremity (n = 96). A 28-question Rasch-Built Overall ALS Disability Scale (ROADS) was constructed with each item scored 0, 1, or 2. The ROADS fulfilled Rasch model requirements, demonstrated improved item targeting compared with the ALSFRS-R, and had test-retest reliability of 0.97. Individual question fit statistics demonstrated infit values from 0.68 to 1.37 and outfit values from 0.66 to 1.43. The difference between the empirical variance explained by the measures and the modeled variance was 0.1%. The ALSFRS-R violated Rasch model expectations and demonstrated disordered thresholds for 9 of 12 questions; 13 of 48 answer choices on the ALSFRS-R were never the most probable answer choice for any overall disability level. Conclusions and Relevance: In this study, the 28-question, self-reported ROADS, which is linearly weighted, had improved item targeting compared with the ALSFRS-R, had high test-retest reliability, and was validated. ROADS may serve as a valuable and easily accessible outcome measure for use in ALS trials and in the clinic with improved responsiveness compared with the ALSFRS-R.

CNS inflammatory demyelinating disorders: MS, NMOSD and MOG antibody associated disease.

Although Multiple Sclerosis is the most common central nervous system (CNS) inflammatory demyelinating disorder, other CNS inflammatory disorders should be included as diagnostic considerations. Neuromyelitis Optica Spectrum Disorder (NMOSD) and myelin oligodendrocyte glycoprotein (MOG) antibody-associated disease are less common but share some clinical characteristics, such as optic neuritis and myelitis, which can make a specific diagnosis challenging. However, these disorders have distinctive and generally different clinical phenotypes, prognosis and management. It is imperative to distinguish each from one another, especially since the treatments (not discussed in this review) can be different. The advent of reliable testing for anti-aquaporin-4 for NMOSD and anti-MOG antibodies has helped significantly; however, diagnosis can remain challenging, especially in sero-negative cases. Clinical indicators are important to guide diagnostic work-up. Careful review of the history, neurological exam, imaging, and/or spinal fluid results are essential to making an accurate diagnosis. In this review, we will examine the clinical presentation, diagnosis, and natural history of these inflammatory CNS disorders.

Baricitinib reverses HIV-associated neurocognitive disorders in a SCID mouse model and reservoir seeding in vitro.

BACKGROUND: Since HIV-associated neurocognitive disorders (HANDs) occur in up to half of HIV-positive individuals, even with combined antiretroviral therapy (cART), adjunctive therapies are needed. Chronic CNS inflammation contributes to HAND and HIV encephalitis (HIVE). Baricitinib is a JAK 1/2 inhibitor approved in the USA, EU, and Japan for rheumatoid arthritis, demonstrating potent inhibition of IL-6, D-dimer, CRP, TNF-α, IFN-α/ß, and other pro-inflammatory cytokines. METHODS: Our modified murine HAND model was used to evaluate the ability of baricitinib to cross the blood-brain barrier (BBB) and modulate monocyte/macrophage-driven HAND. Severity of HAND was measured by assessing cognitive performance of low- and high-dose baricitinib treated versus untreated HAND mice. The severity of brain neuroinflammation was evaluated in these mouse groups after flow cytometric analyses. We also assessed the ability of baricitinib to block events in myeloid and lymphoid cells in vitro that may undergird the persistence of HIV in the central nervous system (CNS) in primary human macrophages (Mϕ) and lymphocytes including HIV replication, HIV-induced activation, reservoir expansion, and reservoir maintenance. RESULTS: In vivo, both doses of 10 and 50 mg/kg qd baricitinib crossed the BBB and reversed behavioral abnormalities conferred by HIV infection. Moreover, baricitinib significantly reduced HIV-induced neuroinflammation marked by glial activation: activated microglia (MHCII+/CD45+) and astrogliosis (GFAP). Baricitinib also significantly reduced the percentage of p24+ human macrophages in mouse brains (p < 0.05 versus HAND mice; t test). In vitro, baricitinib significantly reduced markers of persistence, reservoir size, and reseeding in Mϕ. CONCLUSION: These results show that blocking the JAK/STAT pathway reverses cognitive deficits and curtails inflammatory markers in HAND in mice. Our group recently reported safety and tolerability of ruxolitinib in HIV-infected individuals (Marconi et al., Safety, tolerability and immunologic activity of ruxolitinib added to suppressive ART, 2019), underscoring potential safety and utility of JAK inhibitors for additional human trials. The data reported herein coupled with our recent human trial with JAK inhibitors provide compelling preclinical data and impetus for considering a trial of baricitinib in HAND individuals treated with cART to reverse cognitive deficits and key events driving viral persistence.

Linked CSF reduction of phosphorylated tau and IL-8 in HIV associated neurocognitive disorder.

HIV-associated neurocognitive disorder (HAND) is a common condition in both developed and developing nations, but its cause is largely unknown. Previous research has inconsistently linked Alzheimer's disease (AD), viral burden, and inflammation to the onset of HAND in HIV-infected individuals. Here we simultaneously measured cerebrospinal fluid (CSF) levels of established amyloid and tau biomarkers for AD, viral copy numbers, and six key cytokines in 41 HIV-infected individuals off combination anti-retroviral therapy (14 with HAND) who underwent detailed clinical and neuropsychological characterization, and compared their CSF patterns with those from young healthy subjects, older healthy subjects with normal cognition, and older people with AD. HAND was associated with the lowest CSF levels of phosphorylated tau (p-Tau181) after accounting for age and race. We also found very high CSF levels of the pro-inflammatory interferon gamma-induced protein 10 (IP-10/CXCL10) in HIV regardless of cognition, but elevated CSF interleukin 8 (IL-8/CXCL8) only in HIV-NC but not HAND. Eleven HIV-infected subjects underwent repeat CSF collection six months later and showed strongly correlated longitudinal changes in p-Tau181 and IL-8 levels (R = 0.841). These data suggest reduced IL-8 relative to IP-10 and reduced p-Tau181 to characterize HAND.

CSF Cytokines in Aging, Multiple Sclerosis, and Dementia.

Inflammation is a common process involved in aging, multiple sclerosis (MS), and age-related neurodegenerative disorders such as Alzheimer's disease (AD) and Parkinson's disease (PD), but there is limited evidence for the effects of aging on inflammation in the central nervous system. We collected cerebrospinal fluid (CSF) from 105 healthy control subjects representing a wide age range (23-86), and analyzed levels of cytokines associated innate immunity (TNF-α) and different T-helper subtypes: interferon-gamma induced protein 10 (IP-10) for Th1, interleukin-10 (IL-10) for Th2, and interleukin 8 (IL-8/CXCL8) for Th17. We show that CSF levels of TNF-α, IP-10, and IL-8 all increased linearly with age, but levels of IL-10 demonstrated a U-shaped relationship with age. We further found greater age-related increases in TNF-α, IL-10, and IL-8 relative to increases in IP-10 levels, consistent with a shift from Th1 to other inflammatory phenotypes. Finally, when we analyzed the same four cytokines in people with neurological disorders, we found that MS and AD, but not PD or dementia with Lewy bodies, further accentuated the age-related shift from Th1- to non-Th1-related cytokines. We propose that CSF cytokine levels represent powerful surrogates of brain inflammation and aging, and some, but not all, neurological disorders accelerate the shift away from Th1 phenotypes.

Aging, comorbidities, and the importance of finding biomarkers for HIV-associated neurocognitive disorders.

HIV-associated neurocognitive disorders (HAND) continue to affect a large proportion of persons living with HIV despite effective viral suppression with combined antiretroviral therapy (cART). Importantly, milder versions of HAND have become more prevalent. The pathogenesis of HAND in the era of cART appears to be multifactorial with contributions from central nervous system (CNS) damage that occur prior to starting cART, chronic immune activation, cART neurotoxicity, and various age-related comorbidities (i.e., cardiovascular and cerebrovascular disease, diabetes, hyperlipidemia). Individuals with HIV may experience premature aging, which could also contribute to cognitive impairment. Likewise, degenerative disorders aside from HAND increase with age and there is evidence of shared pathology between HAND and other neurodegenerative diseases, such as Alzheimer's disease, which can occur with or without co-existing HAND. Given the aforementioned complex interactions associated with HIV, cognitive impairment, and aging, it is important to consider an age-appropriate differential diagnosis for HAND as the HIV-positive population continues to grow older. These factors make the accuracy and reliability of the diagnosis of mild forms of HAND in an aging population of HIV-infected individuals challenging. The complexity of current diagnosis of mild HAND also highlights the need to develop reliable biomarkers. Ultimately, the identification of a set of specific biomarkers will be required to achieve early and accurate diagnosis, which will be necessary assuming specific treatments for HAND are developed.

Reversing interferon-alpha neurotoxicity in a HIV-associated neurocognitive disorder mouse model.

OBJECTIVE: Increased brain interferon-alpha (IFNα) is associated with neurodegenerative disorders, including HIV-associated neurocognitive disorders (HAND). HAND occurs in approximately 50% of individuals with HIV despite combined antiretroviral therapy (cART). Therefore, adjunctive therapies must be developed that prevent progression of mild forms of HAND to HIV-associated dementia. Increased IFNα in the CNS has been associated with HAND in patients and in a HAND mouse model. DESIGN AND METHODS: B18R binds IFNα and ameliorates HAND mouse brain histopathology (HIV encephalitis). The HAND model was used to determine if B18R with cART is superior to cART. Behavioral testing [Object recognition Test (ORT)] was used to show that B18R can reverse behavioral deficits. Rat neuronal cultures were used to investigate mechanisms of IFNα neurotoxicity. RESULTS: Mouse brain immunohistochemistry and densitometry suggests that B18R with a common cART regimen improve histopathological markers better than cART alone. B18R reverses ORT behavioral abnormalities in HAND mice. IFNα-treated rat neurons show decreases in PSD-95, suggesting that dendritic spine architecture is disrupted. Decreases in Arf1, a GTP-binding protein, and AMPA receptors on the surface of rat neurons exposed to IFNα suggest the mechanism of IFNα neurotoxicity may relate to decreased Arf1 resulting in destabilization of dendritic spines, decreased PSD-95 expression, and internalization of AMPA receptors. CONCLUSION: B18R reversal of HAND in the mouse model is further evidence that the treatment of IFNα in individuals with HAND could be a viable adjunctive treatment. Investigating pathways of IFNα neurotoxicity may lead to more specific treatments.

Measurement of Human Immunodeficiency Virus p24 Antigen in Human Cerebrospinal Fluid With Digital Enzyme-Linked Immunosorbent Assay and Association With Decreased Neuropsychological Performance.

New tools are needed to understand human immunodeficiency virus central nervous system involvement. Testing 15 cerebrospinal fluid (CSF) samples for p24 antigen, using a high-sensitivity assay, we found a strong correlation trend between CSF p24 concentration and worse neuropsychological performance.

A mouse model of HIV-associated neurocognitive disorders: a brain-behavior approach to discover disease mechanisms and novel treatments.

HIV-associated neurocognitive disorders (HAND) remain highly prevalent despite combined antiretroviral therapy (cART). Although the most common forms of HAND are mild and identified through neuropsychological testing, there is evidence that with aging these mild forms become more prevalent and may advance to the most severe form of HAND, HIV-associated dementia. Therefore, novel therapies must be developed that can be used adjunctively with cART to prevent deterioration or restore normal cognitive function. In order to develop innovative treatments, animal models are used for preclinical testing. Ideally, a HAND animal model should portray similar mild cognitive deficits that are found in humans. A mouse model of HAND is discussed, which demonstrates mild behavioral deficits and has been used to investigate cART and novel treatments for HAND. This model also shows correlations between abnormal mouse behavior due to HIV in the brain and pathological parameters such as gliosis and neuronal abnormalities. A recent advancement utilizes the object recognition test to monitor mouse behavior before and after treatment. It is postulated that this model is well suited for preclinical testing of novel therapies and provides correlations of mild cognitive impairment with pathological markers that can give further insight into the pathophysiology of HAND.

In vitro and Ex vivo Neurotoxic Effects of Efavirenz are Greater than Those of Other Common Antiretrovirals.

Although antiretroviral (ARV) therapy has reduced the incidence of severe dementia associated with HIV infection, there has been a rise in milder neurocognitive complaints. Data from HIV patients taking ARVs have shown measurable neurocognitive improvements during drug cessation, suggesting a neurotoxic role of the therapy itself. Mechanisms underlying potential ARV neurotoxicity have not been thoroughly investigated, however pathologic oxidative stress and mitochondrial dysfunction have been suspected. Using DIV 16 primary rat cortical neuron culture, we tested eight ARVs from the three most commonly prescribed ARV classes: nucleoside/nucleotide reverse transcriptase inhibitors (NRTIs/NtRTIs), non-nucleoside reverse transcriptase inhibitors (NNRTIs), and protease inhibitors (PIs) for effects on neuron viability and morphology after 24 h of drug exposure. Of the tested NRTIs, only stavudine at nearly 100 times the target plasma concentration affected neuron viability with no appreciable change in morphology. Dideoxyinosine induced dendritic simplification at 100 times target plasma concentrations, but did not adversely affect viability. The sole NtRTI, tenofovir, induced dendritic simplification at approximately 3-4 times target plasma concentration, but did not affect viability. Of the tested PIs, only amprenavir decreased neuron viability at nearly 100 times the target plasma concentration. The non-nucleoside reverse transcriptase inhibitor, efavirenz, consistently reduced viability (at 50 µM) and induced dendritic simplification (at 20 µM) nearest the target plasma concentration. Probing mitochondrial energetics of DIV16 cortical neurons after exposure to 20 µM efavirenz showed rapid diminution of mitochondrial-dependent oxygen consumption. Further, 20 µM efavirenz decreased excitability in ex vivo slice culture whereas 2 µM had no effect.

Peroxisome proliferator-activated receptor-γ agonists attenuate biofilm formation by Pseudomonas aeruginosa.

Pseudomonas aeruginosa is a significant contributor to recalcitrant multidrug-resistant infections, especially in immunocompromised and hospitalized patients. The pathogenic profile of P. aeruginosa is related to its ability to secrete a variety of virulence factors and to promote biofilm formation. Quorum sensing (QS) is a mechanism wherein P. aeruginosa secretes small diffusible molecules, specifically acyl homo serine lactones, such as N-(3-oxo-dodecanoyl)-l-homoserine lactone (3O-C12-HSL), that promote biofilm formation and virulence via interbacterial communication. Strategies that strengthen the host's ability to inhibit bacterial virulence would enhance host defenses and improve the treatment of resistant infections. We have recently shown that peroxisome proliferator-activated receptor γ (PPARγ) agonists are potent immunostimulators that play a pivotal role in host response to virulent P. aeruginosa Here, we show that QS genes in P. aeruginosa (strain PAO1) and 3O-C12-HSL attenuate PPARγ expression in bronchial epithelial cells. PAO1 and 3O-C12-HSL induce barrier derangements in bronchial epithelial cells by lowering the expression of junctional proteins, such as zonula occludens-1, occludin, and claudin-4. Expression of these proteins was restored in cells that were treated with pioglitazone, a PPARγ agonist, before infection with PAO1 and 3O-C12-HSL. Barrier function and bacterial permeation studies that have been performed in primary human epithelial cells showed that PPARγ agonists are able to restore barrier integrity and function that are disrupted by PAO1 and 3O-C12-HSL. Mechanistically, we show that these effects are dependent on the induction of paraoxonase-2, a QS hydrolyzing enzyme, that mitigates the effects of QS molecules. Importantly, our data show that pioglitazone, a PPARγ agonist, significantly inhibits biofilm formation on epithelial cells by a mechanism that is mediated via paraoxonase-2. These findings elucidate a novel role for PPARγ in host defense against P. aeruginosa Strategies that activate PPARγ can provide a therapeutic complement for treatment of resistant P. aeruginosa infections.-Bedi, B., Maurice, N. M., Ciavatta, V. T., Lynn, K. S., Yuan, Z., Molina, S. A., Joo, M., Tyor, W. R., Goldberg, J. B., Koval, M., Hart, C. M., Sadikot, R. T. Peroxisome proliferator-activated receptor-γ agonists attenuate biofilm formation by Pseudomonas aeruginosa.