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

Health and sociodemographic factors associated with low muscle strength, muscle mass, and physical performance among people living with HIV

ABSTRACTThis study examined the factors associated with low muscle strength, muscle mass, and physical performance in 331 people living with HIV. Participants completed handgrip as a strength measure, appendicular skeletal muscle mass using bioimpedance analysis, and chair rise was a physical performance measure. Multivariate logistic regression was used to analyze the association between low values on these measures with sociodemographic, HIV-related factors, and comorbidities. Higher body mass index (BMI) (OR = 0.91; CI = 0.86-0.97) and higher CD4/CD8 ratio (OR = 0.38; 95% CI = 0.18-0.82) were associated with decreased likelihood of low handgrip strength. Being non-employed (OR = 2.08; 95% CI = 1.07-4.06), having hypertension (OR = 2.27; 95% CI = 1.13-4.54) and rheumatism (OR = 5.46; 95% CI = 1.68-17.74) increased the chance of low handgrip strength. Higher BMI (OR = 0.43; 95% CI = 0.34-0.56), CD4/CD8 ratio (OR = 0.29; 95% CI = 0.09-0.93), and bioimpedance phase angle (OR = 0.22; 95% CI = 0.12-0.40) were associated with decreased likelihood of low muscle mass. Lastly, having less than eight years of education (OR = 1.87; 95% CI = 1.02-3.41) and being non-employed (OR = 8.18; 95% CI = 3.09-21.61) increased the chance of low chair stand performance. In addition, higher CD4 + lymphocytes count (OR = 0.99; 95% CI = 0.99-0.99) was associated with a decreased likelihood of low chair stand performance. In conclusion, specific and non-specific HIV-related factors are associated with low handgrip strength, low muscle mass, and/or low chair stand performance.

Outcome of Lenalidomide Treatment for Cognitive Impairment Caused by Immune Reconstitution Inflammatory Syndrome in Patients with HIV-Related Cryptococcal Meningitis

Purpose

Cognitive impairment associated with human immunodeficiency virus (HIV)-related cryptococcal meningitis (HCM) in the context of immune reconstitution inflammatory syndrome is difficult to address. This study was a follow-up of lenalidomide treatment outcomes in patients with HCM and cognitive impairment after complete cryptococcal clearance.

Patients and Methods

Seven HCM patients with neuroinflammation and cognitive impairment after complete cryptococcal clearance were enrolled in this prospective study. Neurocognitive assessment, clinical examination and cerebrospinal fluid (CSF) assays were performed before and after lenalidomide treatment.

Results

After lenalidomide treatment, the Montreal Cognitive Assessment [week (W) 0 (median [interquartile range]: 23.0 (13.0–24.0) vs W24: 26.0 (24.0–28.00), P=0.018] and International HIV Dementia Scale scores [W0: 9.0 (2.5–10.5) vs W24: 11.0 (10.00–12.0), P=0.028] improved significantly, mainly in the domain of memory function. There was no significant difference in the Center for Epidemiological Research Depression scores for anxiety and depression before and after treatment. Further stratified analyses revealed that the patients with cognitive improvement group had higher levels of CSF white blood cells [94.0 (44.0–180.0) vs 0 (0–1.5), P=0.032], CSF protein [4.9 (3.0–6.6) vs 0.6 (0.5–0.7), P=0.034], CSF albumin [318.5 (190.9–346.5) vs 33.5 (30.4–46.2), P=0.034], and CSF IgG [160.5 (73.8–256. 0) vs 4.7 (4.3–7.4), P=0.034] but a lower CSF glucose level [2.4 (2.0–2.7) vs 2.8 (2.8–3.9), P=0.032] than the patients with cognitive non-improvement group before treatment. CSF inflammatory cytokines of the growth-related oncogene, interleukin [IL]-10, granulocyte-colony stimulating factor, IL-6, IL-8, complement factor H, tumor necrosis factor-α, and α-2 macroglobulin were obviously decreased in patients with cognitive improvement group after lenalidomide treatment.

Conclusion

Lenalidomide potentially reduces cognitive impairment caused by immune reconstitution inflammatory syndrome in patients with HCM after cryptococcal clearance by inhibiting intracranial inflammation.

Lenalidomide Improves Cognitive Function and Reduces Immune Reconstitution Inflammatory Syndrome in HIV-1-Related Cryptococcal Meningitis

Cryptococcal meningitis (CM) is a common opportunistic infection in patients with acquired immune deficiency syndrome. Although there is a standardized treatment for CM, some patients still have CM-associated immune reconstitution inflammatory syndrome (IRIS) after anti-cryptococcal and antiretroviral therapy, which manifests as cognitive impairment. We report two cases of CM-associated IRIS in human immunodeficiency virus (HIV) patients that were treated with lenalidomide. The treatment yielded a rapid clinical remission and improved cognitive function in both patients; their Montreal Cognitive Assessment (MoCA) and International HIV Dementia Scale (IHDS) scores improved. Furthermore, we evaluated changes in 32 cytokines in the cerebrospinal fluid of two patients and found that both MoCA and IHDS were significantly negatively correlated with inflammation-related factors (growth-related oncogene, interleukin [IL]-10, IL-2, IL-8, macrophage inflammatory protein-1β, tumor necrosis factor [TNF]-α) and significantly positively correlated with dementia-related factors (αβ42 and total tau). Our study reveals the potential of lenalidomide in treating cognitive impairment caused by immune-mediated inflammation in patients with HIV-CM. Moreover, we speculate that lenalidomide improves cognitive function by regulating intracranial inflammation via multiple pathways, not only by TNF-α blocking.

Early Antiretroviral Therapy in AIDS Patients Presenting With Toxoplasma gondii Encephalitis Is Associated With More Sequelae but Not Increased Mortality

Background

Evidence on the optimal time to initiate antiretroviral therapy (ART) in the presence of toxoplasmic encephalitis (TE) is scarce. We compared the impact of early vs. delayed ART initiation on mortality and neurologic complications at discharge in a Brazilian population co-infected with HIV and TE.

Methods

We retrospectively evaluated data from 9 years of hospitalizations at a referral center in Manaus, Amazonas. All ART-naïve hospitalized patients were divided into early initiation treatment (EIT) (0-4 weeks) and delayed initiation treatment (DIT) (>4 weeks). The groups were compared using chi-square test and mortality at 16 weeks.

Results

Four hundred sixty nine patients were included, of whom 357 (76.1%) belonged to the EIT group. The median CD4⁺ lymphocyte count and CD4⁺/CD8⁺ ratio were 53 cells/mm³ and 0.09, respectively. Mortality rate and presence of sequelae were 4.9% (n = 23) and 41.6% (n = 195), respectively. Mortality was similar between groups (p = 0.18), although the EIT group had the highest prevalence of sequelae at discharge (p = 0.04). The hazard ratio for death at 16 weeks with DIT was 2.3 (p = 0.18). The necessity for intensive care unit admission, mechanical ventilation, and cardiopulmonary resuscitation were similar between groups.

Conclusion

In patients with AIDS and TE, early ART initiation might have a detrimental influence on the occurrence of sequelae.

Epidemiology, Pathophysiology, Diagnosis, and Management of Cerebral Toxoplasmosis

Toxoplasma gondii is known to infect a considerable number of mammalian and avian species and a substantial proportion of the world's human population. The parasite has an impressive ability to disseminate within the host's body and employs various tactics to overcome the highly regulatory blood-brain barrier and reside in the brain. In healthy individuals, T. gondii infection is largely tolerated without any obvious ill effects. However, primary infection in immunosuppressed patients can result in acute cerebral or systemic disease, and reactivation of latent tissue cysts can lead to a deadly outcome. It is imperative that treatment of life-threatening toxoplasmic encephalitis is timely and effective. Several therapeutic and prophylactic regimens have been used in clinical practice. Current approaches can control infection caused by the invasive and highly proliferative tachyzoites but cannot eliminate the dormant tissue cysts. Adverse events and other limitations are associated with the standard pyrimethamine-based therapy, and effective vaccines are unavailable. In this review, the epidemiology, economic impact, pathophysiology, diagnosis, and management of cerebral toxoplasmosis are discussed, and critical areas for future research are highlighted.

Assessing and mitigating risk of infection in patients with multiple sclerosis on disease modifying treatment

Introduction: The important development that the multiple sclerosis (MS) treatment field has experienced in the last years comes along with the need of dealing with new adverse events such as the increase risk of infections. In the shared therapeutic decision-making process, the MS expert neurologist should also balance the risks of specific infections under each particular treatment and be familiar with new mitigation strategies.Areas covered: In this review, the authors provide an up-to-date review of the infection risk associated with MS treatments with a specific focus on risk mitigating strategies. The search was conducted using Pubmed® database (2000 - present) to identify publications that reported infection rates and infection complications for each treatment (interferon beta, glatiramer acetate, teriflunomide, dimethyl fumarate, fingolimod, cladribine, natalizumab, alemtuzumab, rituximab, and ocrelizumab).Expert opinion: Since the emergence of the first natalizumab-related PML case, the arrival of new MS therapies has come hand in hand with new infectious complications. MS-specialist neurologist has to face new challenges regarding the management of immunosuppression-related infectious complications. The implementation of patient-centered management focus on preventive and mitigating strategies with a multidisciplinary approach should be seen in the future as a marker of excellence of MS management.

Cerebral toxoplasmosis in HIV-infected patients over 2015-2018 (a case study of Russia)

Cerebral toxoplasmosis is a leading cause of the central nervous system disorders in acquired immune deficiency syndrome. This study aimed to investigate the clinical course of cerebral toxoplasmosis in human immunodeficiency virus (HIV)-infected individuals. The study included 90 HIV-infected patients with cerebral toxoplasmosis, who underwent inpatient treatment. In case of positive enzyme immunoassay, HIV infection was confirmed with the immunoblot test. The HIV-1 ribonucleic acid level was determined using the polymerase chain reaction method. The flow cytometry was used for counting CD4 (cluster of differentiation 4 cells). Pathomorphological examination included the autopsy, gross and microscopic examination of internal organs, histological and other methods. The incidence of cerebral toxoplasmosis significantly increases at the CD4 count below 100 cells/μl, P < 0.001, and at the HIV viral load above 50 copies/ml, P < 0.05. The clinical picture of cerebral toxoplasmosis included focal symptoms, cognitive impairment, toxic syndrome, mild cerebral symptoms and a meningeal symptom. Given the absence of a specific clinical picture and the absence of abnormal laboratory and instrumental findings, the cerebral toxoplasmosis needs to be diagnosed with a number diagnostic methods combined: clinical examination, laboratory testing, immunological examination, molecular genetic testing and neuroradiological imaging.

HIV-Negative Cryptococcal Meningoencephalitis Results in a Persistent Frontal-Subcortical Syndrome

Twenty-seven previously healthy (of 36 consecutive eligible patients), HIV-negative cryptococcal meningoencephalitis (CM) patients underwent comprehensive neuropsychological evaluation during the late post-treatment period (1.3-4 years post diagnosis), assessing attention, language, learning, memory, visuospatial, executive function, information processing, psychomotor functioning, as well as mood symptoms. Seven of eight domains (all except attention) showed increased percentages of CM patients scoring in the less than 16^th percentile range compared to standardized normative test averages, adjusted for education level and age. Comparison with a matched archival dataset of mild cognitive impairment/Alzheimer's disease patients showed that CM patients exhibited relative deficits in psychomotor and executive function with fewer deficits in memory and learning, consistent with a frontal-subcortical syndrome. MRI evaluation at the time of testing demonstrated an association of lower neuropsychological functioning with ventriculomegaly. These studies suggest that CM should be included in the list of treatable causes of dementia in neurological work ups. Future studies are needed to identify diagnostic and treatment regimens that may enhance neurological function after therapy.

Neurocognitive and functional impairment in adult and paediatric tuberculous meningitis

In those who survive tuberculous meningitis (TBM), the long-term outcome is uncertain; individuals may suffer neurocognitive, functional and psychiatric impairment, which may significantly affect their ability to lead their lives as they did prior to their diagnosis of TBM. In children who survive, severe illness has occurred at a crucial timepoint in their development, which can lead to behavioural and cognitive delay. The extent and nature of this impairment is poorly understood, particularly in adults. This is in part due to a lack of observational studies in this area but also inconsistent inclusion of outcome measures which can quantify these deficits in clinical studies. This leads to a paucity of appropriate rehabilitative therapies available for these individuals and their caregivers, as well as burden at a socioeconomic level. In this review, we discuss what is known about neurocognitive impairment in TBM, draw on lessons learnt from other neurological infections and discuss currently available and emerging tools to evaluate function and cognition and their value in TBM. We make recommendations on which measures should be used at what timepoints to assess for impairment, with a view to optimising and standardising assessment of neurocognitive and functional impairment in TBM research.

Human Immunodeficiency Virus in the Brain-Culprit or Facilitator?

Introduction:

Human immunodeficiency virus (HIV) enters the brain early, where it can persist, evolve, and become compartmentalized. Central nervous system (CNS) disease can be attributed to HIV alone or to the complex interplay between the virus and other neurotropic pathogens.

Aim:

The current review aims to describe the direct impact of HIV on the brain as well as its relationship with other pathogens from a practitioner’s perspective, to provide a general clinical overview, brief workup, and, whenever possible, treatment guidance.

Methods:

A review of PubMed was conducted to identify studies on neuropathogenesis of HIV in relation to host responses. Furthermore, the interaction between the CNS pathogens and the host damage responses were revised in the setting of advanced and also well-controlled HIV infection.

Results:

Similar to other pathogens, HIV leads to CNS immune activation, inflammation, and viral persistence. Therefore, almost half of the infected individuals present with neurocognitive disorders, albeit mild. Compartmentalized HIV in the CNS can be responsible in a minority of cases for the dramatic presentation of symptomatic HIV escape. Disruption of the immune system secondary to HIV may reactivate latent infections or allow new pathogens to enter the CNS. Opportunistic infections with an inflammatory component are associated with elevated HIV loads in the cerebrospinal fluid and also with greater cognitive impairment. The inflammatory immune reconstitution syndrome associated with CNS opportunistic infections can be a life-threatening condition, which needs to be recognized and managed by efficiently controlling the pathogen burden and timely balanced combination antiretroviral therapy. Latent neurotropic pathogens can reactivate in the brain and mimic HIV-associated severe neurological diseases or contribute to neurocognitive impairment in the setting of stable HIV infection.

Conclusions:

As HIV can be responsible for considerable brain damage directly or by facilitating other pathogens, more effort is needed to recognize and manage HIV-associated CNS disorders and to eventually target HIV eradication from the brain.

Central nervous system infection with Toxoplasma gondii

Central nervous system infection by Toxoplasma gondii, or Toxoplasma encephalitis, is the most common cause of brain mass lesions in human immunodeficiency virus (HIV)-infected patients. It usually presents as one or more brain abscesses, but it can also cause a diffuse encephalitis or ventriculitis. Individuals who are Toxoplasma immunoglobulin G-seropositive, who have peripheral blood CD4+ T-cell concentrations below 200/μL, are not on antiretroviral therapy, and are not taking trimethoprim-sulfamethoxazole to prevent Pneumocystis pneumonia, are at particular risk for Toxoplasma encephalitis. Neuroimaging typically shows round, isodense or hyperdense lesions in the hemispheric gray-white junction, deep white matter, or basal ganglia that enhance with contrast in a ring, nodular, or homogeneous pattern. In appropriate patients, response to an empiric treatment trial can establish the diagnosis. Immune reconstitution inflammatory syndrome is uncommon in HIV-infected patients treated for Toxoplasma encephalitis and combination antiretroviral therapy is an integral part of toxoplasmosis treatment.

Neurocognitive function in HIV-infected persons with asymptomatic cryptococcal antigenemia: a comparison of three prospective cohorts

BACKGROUND

HIV-infected persons with detectable cryptococcal antigen (CrAg) in blood have increased morbidity and mortality compared with HIV-infected persons who are CrAg-negative. This study examined neurocognitive function among persons with asymptomatic cryptococcal antigenemia.

METHODS

Participants from three prospective HIV cohorts underwent neurocognitive testing at the time of antiretroviral therapy (ART) initiation. Cohorts included persons with cryptococcal meningitis (N = 90), asymptomatic CrAg + (N = 87), and HIV-infected persons without central nervous system infection (N = 125). Z-scores for each neurocognitive test were calculated relative to an HIV-negative Ugandan population with a composite quantitative neurocognitive performance Z-score (QNPZ-8) created from eight tested domains. Neurocognitive function was measured pre-ART for all three cohorts and additionally after 4 weeks of ART (and 6 weeks of pre-emptive fluconazole) treatment among asymptomatic CrAg + participants.

RESULTS

Cryptococcal meningitis and asymptomatic CrAg + participants had lower median CD4 counts (17 and 26 cells/μL, respectively) than the HIV-infected control cohort (233 cells/μL) as well as lower Karnofsky performance status (60 and 70 vs. 90, respectively). The composite QNPZ-8 for asymptomatic CrAg + (-1.80 Z-score) fell between the cryptococcal meningitis cohort (-2.22 Z-score, P = 0.02) and HIV-infected controls (-1.36, P = 0.003). After four weeks of ART and six weeks of fluconazole, the asymptomatic CrAg + cohort neurocognitive performance improved (-1.0 Z-score, P < 0.001).

CONCLUSION

Significant deficits in neurocognitive function were identified in asymptomatic CrAg + persons with advanced HIV/AIDS even without signs or sequelae of meningitis. Neurocognitive function in this group improves over time after initiation of pre-emptive fluconazole treatment and ART, but short term adherence support may be necessary.

Neurobehavioral Manifestations of Human Immunodeficiency Virus/AIDS: Diagnosis and Treatment

Behavioral disorders are common in persons infected with human immunodeficiency virus (HIV). The differential includes preexisting psychiatric diseases, substance abuse, direct effects of HIV infection, opportunistic infection, and the adverse effects of medical therapies. Many patients have more than one contributing or comorbid problem to explain these behavioral changes. The differential should always include consideration of psychosocial, genetic, and medical causes of disease. Treatment strategies must take into account the coadministration of antiretroviral therapy and the specific neurologic problems common in patients infected with HIV.

Cognitive impairment in patients with AIDS - prevalence and severity

The advent of highly active antiretroviral therapy has prolonged the life expectancy of HIV patients and decreased the number of adults who progress to AIDS and HIV-associated dementia. However, neurocognitive deficits remain a pronounced consequence of HIV/AIDS. HIV-1 infection targets the central nervous system in subcortical brain areas and leads to high rates of delirium, depression, opportunistic central nervous system infections, and dementia. Long-term HIV replication in the brain occurs in astrocytes and microglia, allowing the virus to hide from antiviral medication and later compromise neuronal function. The associated cognitive disturbance is linked to both viral activity and inflammatory and other mediators from these immune cells that lead to the damage associated with HIV-associated neurocognitive disorders, a general term given for these disturbances. We review the severity and prevalence of the neuropsychiatric complications of HIV including delirium, neurobehavioral impairments (depression), minor cognitive-motor dysfunction, and HIV-associated dementia.

Predictors of neurocognitive outcomes on antiretroviral therapy after cryptococcal meningitis: a prospective cohort study

Cryptococcal meningitis is the most common cause of adult meningitis in Africa, yet neurocognitive outcomes are unknown. We investigated the incidence and predictors of neurologic impairment among cryptococcal survivors. HIV-infected, antiretroviral-naive Ugandans with cryptococcal meningitis underwent standardized neuropsychological testing at 1, 3, 6, and 12 months. A quantitative neurocognitive performance z-score (QNPZ) was calculated based on population z-scores from HIV-negative Ugandans (n = 100). Comparison was made with an HIV-infected, non-meningitis cohort (n = 110). Among 78 cryptococcal meningitis survivors with median CD4 count of 13 cells/μL (interquartile range: 6-44), decreased global cognitive function occurred through 12 months compared with the HIV-infected, non-cryptococcosis cohort (QNPZ-6 at 12 months, P = 0.036). Tests of performance in eight cognitive domains was impaired 1 month after cryptococcal diagnosis; however, cryptococcal meningitis survivors improved their global neurocognitive function over 12 months with residual impairment (mean z-scores < -1), only in domains of motor speed, gross motor and executive function at 12 months. There was no evidence that neurocognitive outcome was associated with initial demographics, HIV parameters, or meningitis severity. Paradoxically, persons with sterile CSF cultures after 14 days of induction amphotericin therapy had worse neurocognitive outcomes than those still culture-positive at 14 days (P = 0.002). Cryptococcal meningitis survivors have significant short-term neurocognitive impairment with marked improvement over the first 12 months. Few characteristics related to severity of cryptococcosis, including Cryptococcus burden, were associated with neurocognitive outcome.

An algorithmic approach to structural imaging in dementia

Accurate and timely diagnosis of dementia is important to guide management and provide appropriate information and support to patients and families. Currently, with the exception of individuals with genetic mutations, postmortem examination of brain tissue remains the only definitive means of establishing diagnosis in most cases, however, structural neuroimaging, in combination with clinical assessment, has value in improving diagnostic accuracy during life. Beyond the exclusion of surgical pathology, signal change and cerebral atrophy visible on structural MRI can be used to identify diagnostically relevant imaging features, which provide support for clinical diagnosis of neurodegenerative dementias. While no structural imaging feature has perfect sensitivity and specificity for a given diagnosis, there are a number of imaging characteristics which provide positive predictive value and help to narrow the differential diagnosis. While neuroradiological expertise is invaluable in accurate scan interpretation, there is much that a non-radiologist can gain from a focused and structured approach to scan analysis. In this article we describe the characteristic MRI findings of the various dementias and provide a structured algorithm with the aim of providing clinicians with a practical guide to assessing scans.

Neurocognitive impairment in HIV-infected individuals with previous syphilis

Cognitive impairment is common in HIV-infected individuals, as is syphilis. Treponema pallidum, the bacterium that causes syphilis, invades the central nervous system early in disease. We hypothesized that HIV-infected patients with a history of syphilis or neurosyphilis would have more cognitive impairment than HIV-infected individuals without these infections. Eighty-two of 1574 enrollees in CHARTER, a prospective, observational study, had reactive serum rapid plasma reagin (RPR) tests. They were matched to 84 controls with non-reactive RPR by age, gender, ethnicity and HIV risk factor. Participants underwent comprehensive neuropsychological (NP) evaluations. RPR results were confirmed and serum fluorescent treponemal antibody absorption (FTA-ABS) test reactivity determined at a central laboratory. Sera from 101 of 166 participants were FTA-ABS reactive, indicating past or current syphilis. Among the 136 individuals without confounding conditions, compared with patients who had never had syphilis, those with prior syphilis had a greater number of impaired NP test domains (1.90 SD [1.77] versus 1.25 [1.52], P = 0.03), a higher global deficit score (0.47 [0.46] versus 0.31 [0.33], P = 0.03), and more were impaired in the NP learning domain (36 [42.9%] of 84 versus 13 [25.0%] of 52, P = 0.04). These effects of prior syphilis remained after controlling for education and premorbid intelligence.

Cerebral β-amyloid deposition predicts HIV-associated neurocognitive disorders in APOE ε4 carriers

OBJECTIVE

The apolipoprotein E (APOE) ε4 allele enhances cerebral accumulation of β-amyloid (Aβ) and is a major risk factor for sporadic Alzheimer's disease. We hypothesized that HIV-associated neurocognitive disorders (HAND) would be associated with the APOE ε4 genotype and cerebral Aβ deposition.

DESIGN

Clinicopathological study of HIV-infected adults from four prospective cohorts in the US National NeuroAIDS Tissue Consortium.

METHODS

We used multivariable logistic regressions to model outcomes [Aβ plaques (immunohistochemistry) and HAND (standard criteria)] on predictors [APOE ε4 (allelic discrimination assay), older age (≥50 years), Aβ plaques, and their two-way interactions] and comorbid factors.

RESULTS

Isocortical Aβ deposits generally occurred as diffuse plaques and mild-to-moderate amyloid angiopathy. Isocortical phospho-Tau-immunoreactive neurofibrillary lesions were sparse. The APOE ε4 and older age were independently associated with the presence of Aβ plaques [adjusted odds ratio (OR) 10.16 and 5.77, 95% confidence interval (CI) 2.89 - 35.76 and 1.91-17.48, P = 0.0003 and 0.0019, respectively, n = 96]. The probability of HAND was increased in the presence of Aβ plaques among APOE ε4 carriers (adjusted OR 30.00, 95% CI 1.41-638.63, P = 0.029, n = 15), but not in non-ε4 carriers (n = 57).

CONCLUSION

The APOE ε4 and older age increased the likelihood of cerebral Aβ plaque deposition in HIV-infected adults. Generally, Aβ plaques in HIV brains were immunohistologically different from those in symptomatic Alzheimer's disease brains. Nonetheless, Aβ plaques were associated with HAND among APOE ε4 carriers. The detection of APOE ε4 genotype and cerebral Aβ deposition biomarkers may be useful in identifying living HAND patients who could benefit from Aβ-targeted therapies.

Antioxidant sestrin-2 redistribution to neuronal soma in human immunodeficiency virus-associated neurocognitive disorders

Sestrin-2 is involved in p53-dependent antioxidant defenses and in the maintenance of metabolic homeostasis. We hypothesize that sestrin-2 expression is altered in the brains of subjects diagnosed with human immunodeficiency virus (HIV)-associated neurocognitive disorders (HAND) due to neuronal oxidative stress. We studied sestrin-2 immunoreactivity in 42 isocortex sections from HIV-1-infected subjects compared to 18 age-matched non-HIV controls and 19 advanced Alzheimer's disease (AD) cases. With HIV infection, the sestrin-2 immunoreactivity pattern shifted from neuropil predominance (N) to neuropil and neuronal-soma co-dominance (NS) and neuronal-soma predominance (S; P < 0.0001, Chi-square test for linear trend). Among HIV cases showing the NS or S pattern, HAND cases were preferentially associated with the S pattern (n = 10 of 20) compared to cognitively intact cases (n = 1 of 11; P = 0.047, Fisher's exact test). In AD brains, sestrin-2 immunoreactivity was mostly intense in the neuropil and co-localized with phospho-Tau immunoreactivity in a subset of neurofibrillary lesions. Phospho-Tau-immunoreactive neurofibrillary lesions were rare in HIV cases and their occurrence was not associated with HAND. Levels of isocortical 8-hydroxy-deoxyguanosine (marker of nucleic acid oxidation) immunoreactivity were not significantly altered in HAND cases compared to cognitively intact HIV cases. In conclusion, the sestrin-2 immunoreactivity redistribution to neuronal soma in HAND suggests unique involvement of sestrin-2 in the pathophysiology of HAND, which is different from the role of sestrin-2 in AD pathogenesis. Alternatively, the difference in sestrin-2 immunoreactivity distribution between HAND and AD may be related to different degrees of severity or stages of oxidative stress.

Increased cortical expression of FK506 binding protein-51 in HIV-associated neurocognitive disorders

FK506 binding protein (FKBP)-51 and FKBP52 act as molecular chaperones to control glucocorticoid receptor (GR) sensitivity. Dysregulation of proteins involved in GR-mediated signaling can lead to maladaptive stress response and aging-related cognitive decline. As HIV infection is related to chronic stress, we hypothesized that altered cortical expression of these proteins was associated with HIV-associated neurocognitive disorders (HAND). We used quantitative immunohistochemistry to assess expression levels of these proteins in the mid-frontal gyrus of 55 HIV-infected subjects free of cerebral opportunistic diseases compared to 20 age-matched non-HIV controls. The immunoreactivity normalized to the neuroanatomic area measured (IRn) for FKBP51 was increased in HIV subjects both in the cortex and subcortical white matter (p < 0.0001, U test), while no significant alterations were observed for GR or FKBP52. Notably, the cortical FKBP51 IRn was higher in HAND subjects than in cognitively normal HIV subjects (p = 0.02, U test). There was also a trend for increasing cortical FKBP51 IRn with the increasing severity of HAND (p = 0.08, Kruskal-Wallis test). No significant changes in FKBP51 IRn were found with respect to hepatitis C virus infection, lifetime methamphetamine use, or antiretroviral treatment in HIV subjects. In conclusion, the increased cortical expression of FKBP51 (an inhibitor for GR activity) might represent negative feedback in an attempt to reduce GR sensitivity in the setting of chronic stress-induced elevation of GR-mediated signaling inherent in HIV infection. The further increased FKBP51 expression might lead to maladaptive stress response and HAND.

Neurologic presentations of AIDS

The human immunodeficiency virus (HIV), the cause of AIDS, has infected an estimated 33 million individuals worldwide. HIV is associated with immunodeficiency, neoplasia, and neurologic disease. The continuing evolution of the HIV epidemic has spurred an intense interest in a hitherto neglected area of medicine, neuroinfectious diseases and their consequences. This work has broad applications for the study of central nervous system (CNS) tumors, dementias, neuropathies, and CNS disease in other immunosuppressed individuals. HIV is neuroinvasive (can enter the CNS), neurotrophic (can live in neural tissues), and neurovirulent (causes disease of the nervous system). This article reviews the HIV-associated neurologic syndromes, which can be classified as primary HIV neurologic disease (in which HIV is both necessary and sufficient to cause the illness), secondary or opportunistic neurologic disease (in which HIV interacts with other pathogens, resulting in opportunistic infections and tumors), and treatment-related neurologic disease (such as immune reconstitution inflammatory syndrome).