Neurologic presentations of AIDS

Interplays Between Matrix Metalloproteinases and Neurotropic Viruses: An Overview

Matrix metalloproteinases (MMPs) are a diverse group of proteases involved in various physiological and pathological processes through modulation of extracellular matrix (ECM) components, cytokines, and growth factors. In the central nervous system (CNS), MMPs play a major role in CNS development, plasticity, repair, and reorganisation contributing to learning, memory, and neuroimmune response to injury. MMPs are also linked to various neurological disorders such as Alzheimer's disease, Parkinson's disease, cerebral aneurysm, stroke, epilepsy, multiple sclerosis, and brain cancer suggesting these proteases as key regulatory factors in the nervous system. Moreover, MMPs have been involved in the pathogenesis of neurotropic viral infections via dysregulation of various cellular processes, which may highlight these factors as potential targets for the treatment and control of neurological complications associated with viral pathogens. This review provides an overview of the roles of MMPs in various physiological processes of the CNS and their interactions with neurotropic viral pathogens.

Blood-borne viruses and neurological manifestations: An overview

Infections caused by blood-borne viruses, such as human immunodeficiency virus (HIV), human T-lymphotropic virus (HTLV), hepatitis C virus (HCV), and hepatitis B virus (HBV), are systemic diseases that can lead to a wide range of pathological manifestations. Besides causing severe immune and hepatic disorders, these viral pathogens can also induce neurological dysfunctions via both direct and indirect mechanisms. Neurological dysfunctions are one of the most common manifestations caused by these viruses that can also serve as indicators of their infection, impacting the clinical presentation of the disease. The main neurological manifestations of these blood-borne viral pathogens consist of several central and peripheral nervous system (CNS and PNS, respectively) dysfunctions. The most common neurological manifestations of HIV, HTLV, HCV, and HBV include HIV-associated peripheral neuropathy (PN), HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP), and HCV-/HBV-associated PN, respectively. Nonetheless, patients infected with these viruses may experience other neurological disorders, either associated with these conditions or manifesting in isolation, which can often go unnoticed or undiagnosed by physicians. The present review aims to provide an overview of the latest evidence on the relationship between blood-borne viruses and neurological disorders to highlight neurological conditions that may be somewhat overlooked by mainstream literature and physicians.

Moderate-to-severe cognitive impairment is associated with both recent and chronic alcohol misuse in people with HIV: The New Orleans alcohol use in HIV (NOAH) study

BACKGROUND

Human immunodeficiency virus (HIV) profoundly impacts the nervous system, leading to neurological deficits including HIV-associated neurocognitive disorder (HAND). HAND represents the most common neurological comorbidity among people with HIV (PWH), and alcohol use may exacerbate cognitive deficits, especially in vulnerable populations. This study investigated relationships between alcohol use and cognition in an underserved cohort of PWH, on the hypothesis that alcohol misuse exacerbates cognitive deficits.

METHODS

Data collected from participants (n = 259; 66.7% male; mean age 52 ± 10 years) enrolled in the New Orleans Alcohol Use in HIV (NOAH) study were utilized for cross-sectional analysis. Cognitive function was assessed using the Montreal Cognitive Assessment (MoCA), and alcohol use was comprehensively measured using four metrics: the Alcohol Use Disorders Identification Test (AUDIT), 30-day timeline follow back (TLFB), lifetime drinking history, and phosphatidylethanol (PEth) levels.

RESULTS

The average MoCA score among participants was 20.7 ± 4.5, with 86.5% demonstrating cognitive impairment (MoCA < 26). Individuals with MoCA scores below 18 (moderately or severely cognitively impaired) had a higher frequency of recent severe alcohol misuse and greater lifetime alcohol consumption. Participants at increased risk for AUD (AUDIT ≥ 16) also had worse global cognition and memory task performance than those with lower AUDIT scores; this was particularly true among those aged 50 and older. Analysis of the MoCA sub-score data indicated that participants with increased AUD risk had impairments in the cognitive domains of language and memory.

CONCLUSIONS

Our findings demonstrate a high prevalence of cognitive impairment in the NOAH cohort and suggest that alcohol misuse contributes to global cognitive deficits in PWH, especially among individuals aged 50 and older. Further exploration of the impact of alcohol use on specific cognitive domains, including memory and language, should incorporate additional cognitive tasks. These findings highlight the importance of considering alcohol use and AUD risk as significant factors that may exacerbate cognitive deficits in vulnerable populations, including older PWH.

Unravelling the triad of neuroinvasion, neurodissemination, and neuroinflammation of human immunodeficiency virus type 1 in the central nervous system

Since the identification of human immunodeficiency virus type 1 (HIV-1) in 1983, many improvements have been made to control viral replication in the peripheral blood and to treat opportunistic infections. This has increased life expectancy but also the incidence of age-related central nervous system (CNS) disorders and HIV-associated neurodegeneration/neurocognitive impairment and depression collectively referred to as HIV-associated neurocognitive disorders (HAND). HAND encompasses a spectrum of different clinical presentations ranging from milder forms such as asymptomatic neurocognitive impairment or mild neurocognitive disorder to a severe HIV-associated dementia (HAD). Although control of viral replication and suppression of plasma viral load with combination antiretroviral therapy has reduced the incidence of HAD, it has not reversed milder forms of HAND. The objective of this review, is to describe the mechanisms by which HIV-1 invades and disseminates in the CNS, a crucial event leading to HAND. The review will present the evidence that underlies the relationship between HIV infection and HAND. Additionally, recent findings explaining the role of neuroinflammation in the pathogenesis of HAND will be discussed, along with prospects for treatment and control.

Complete response to front-line therapies is associated with long-term survival in HIV-related lymphomas in Taiwan

BACKGROUND

The prognosis for people living with HIV (PLWH) who develop lymphomas has been greatly improved by combination antiretroviral therapy (cART) and anti-CD20 monoclonal antibodies. However, real-world clinical data on this patient group in Asia are limited.

METHODS

Treatment outcomes were retrospectively examined for 104 PLWH with lymphomas between 2000 and 2019. The cohort comprised five PLWH with Hodgkin lymphoma (HL) and 99 with non-Hodgkin lymphomas, including 61 with diffuse large B-cell lymphoma (DLBCL), 19 with Burkitt lymphoma (BL), nine with primary central nervous system lymphoma (PCNSL) and ten with other subtypes.

RESULTS

The 5-year overall survival (OS) rates were as follows: HL (100%), PCNSL (76.2%), other subtypes (60.0%), BL (57.4%), and DLBCL (55.6%). Individuals who achieved complete response (CR) to front-line therapies had a significantly better 5-year OS rate than those without (96.2% vs. 17.8%, p < 0.001). PLWH who received cART for ≤6 months had significantly lower CD4+ T-cell counts at lymphoma diagnosis than those who received cART for longer periods (p = 0.048). Additionally, the 5-year OS rate was better for PLWH who received cART for ≤6 months before lymphomas diagnosis than those who received cART for longer periods (64.5% vs. 51.9%, p = 0.114).

CONCLUSIONS

PLWH with DLBCL or BL had OS rates compatible to patients without HIV infection. Better outcomes for patients achieving CR to front-line therapy and those with shorter cART duration before lymphoma diagnosis suggest an underlying biological distinction in the lymphomas and the involvement of immunity, which warrants further studies.

Understanding HIV-associated neurocognitive and neurodegenerative disorders (neuroAIDS): enroute to achieve the 95-95-95 target and sustainable development goal for HIV/AIDS response

The world's sustained commitment to the HIV/AIDS response and to reaching the 2030 Sustainable Development Goal (SDG) of "ending AIDS" as a public health issue is indicated by the ambitious 95-95-95 targets for all relevant populations. Neurological conditions of AIDS (neuroAIDS) are the most significant and severe central nervous system complication associated with HIV infection in which viral antigens can enter in the brain by breaching the blood brain barrier and cause dementia, neuroinflammation and encephalopathy. The prevalence of neuroAIDS is 10-50% in people with advanced HIV disease, whereas 5-25% in people on ART. Currently, MRI, CT and other tools are used to diagnose the neuroAIDS/ HIV-associated dementia and antiretroviral therapy is widely used to treat the neuroAIDS. In spite of many advanced tools and pathogenesis of neuroAIDS, developing therapeutics remains a formidable challenge. Long acting cabotegravir type of therapeutics is an advanced stage of research which shows good results for the treatment of neuroAIDS. Therefore, here we are discussing the recent insights of the pathogenesis, possible therapeutics and current strategies and treatment to overcome the neuroAIDS.

Bacterial ribosomal RNA detection in cerebrospinal fluid using a viromics approach

BACKGROUND

In patients with central nervous system (CNS) infections identification of the causative pathogen is important for treatment. Metagenomic next-generation sequencing techniques are increasingly being applied to identify causes of CNS infections, as they can detect any pathogen nucleic acid sequences present. Viromic techniques that enrich samples for virus particles prior to sequencing may simultaneously enrich ribosomes from bacterial pathogens, which are similar in size to small viruses.

METHODS

We studied the performance of a viromic library preparation technique (VIDISCA) combined with low-depth IonTorrent sequencing (median ~ 25,000 reads per sample) for detection of ribosomal RNA from common pathogens, analyzing 89 cerebrospinal fluid samples from patients with culture proven bacterial meningitis.

RESULTS

Sensitivity and specificity to Streptococcus pneumoniae (n = 24) before and after optimizing threshold parameters were 79% and 52%, then 88% and 90%. Corresponding values for Neisseria meningitidis (n = 22) were 73% and 93%, then 67% and 100%, Listeria monocytogenes (n = 24) 21% and 100%, then 27% and 100%, and Haemophilus influenzae (n = 18) 56% and 100%, then 71% and 100%. A higher total sequencing depth, no antibiotic treatment prior to lumbar puncture, increased disease severity, and higher c-reactive protein levels were associated with pathogen detection.

CONCLUSION

We provide proof of principle that a viromic approach can be used to correctly identify bacterial ribosomal RNA in patients with bacterial meningitis. Further work should focus on increasing assay sensitivity, especially for problematic species (e.g. L. monocytogenes), as well as profiling additional pathogens. The technique is most suited to research settings and examination of idiopathic cases, rather than an acute clinical setting.

Epidemiology of HIV-associated peripheral neuropathy in people living with human immunodeficiency virus infection in Greece

BACKGROUND

Peripheral neuropathy is among the most common complications among people with HIV with prevalence rates varying widely among studies (10-58%).

OBJECTIVE

This study aims to assess the prevalence of HIV-associated peripheral neuropathy among HIV-positive people in Northern Greece monitored during the last 5-year period and investigate possible correlations with antiretroviral therapy, disease staging, and potential risk factors, as there is no prior epidemiological record in Greek patients.

METHODS

Four hundred twenty patients were divided into a group with peripheral neuropathy (n = 269), and those without (n = 151). Peripheral neuropathy was assessed with a validated Peripheral Neuropathy Screening tool. Statistical analyses were performed with SPSS, were two-tailed, and p-value was set at 0.05.

RESULTS

The incidence of peripheral neuropathy was estimated at 35.9%. Age was found to correlate with higher odds of developing HIV-peripheral neuropathy, rising by 4%/year. Females encountered 77% higher probability to develop peripheral neuropathy. Stage 3 of the disease associated with higher occurrence of peripheral neuropathy (96% as compared to stage-1 patients). Among patients with peripheral neuropathy, the duration of antiretroviral therapy was found to be longer than in those without.

CONCLUSIONS

Peripheral neuropathy remains one of the most common complications regardless of the antiretroviral-therapy type, indicating the involvement of other risk factors in its occurrence, such as the stage of the disease, age and gender. Therefore, the treating physician should screen patients as early and frequently as possible upon HIV-diagnosis to prevent the progression of this debilitating condition so that prolonged life-expectancy is accompanied by a good quality of life.

Neurological disorders in HIV: Hope despite challenges

Introduction

Human Immunodeficiency virus (HIV) is a virus that causes several diseases by attacking the human immune system. It is transmitted by contact with certain bodily fluids of an infected person, most commonly during unprotected sex, through sharing needles, or from mother to baby during pregnancy, birth or breastfeeding. The central nervous system is not spared from this virus, as HIV has been shown to induce several neurological disorders. However most neurological pathologies (such as dementia, infections, meningitis, and neuropathy) rarely show until late stages, in this case, after the patients develop acquired immunodeficiency syndrome (AIDS). This article aims to review the neurological disorders in the HIV population and the attempts initiated to limit the disease.

Methodology

Data were collected from medical journals published on PubMed, Ovid MEDLINE, Science Direct and Embase bibliographical databases with a predefined search strategy. All articles considering neurological disorders associated with HIV were considered.

Results

To date, the pathogenesis of HIV‐associated neurological complications remains poorly elucidated; thus, imposing a hindrance and limitations on the treatment options. Nevertheless, some studies have reported alterations in dendritic spine as the causative agent for developing brain damage.

Conclusion

HIV remains one of the most serious global health challenges, with neurological manifestations imposing a major concern among patients with HIV. Despite the availability and efficacy of antiretroviral therapies, yet, the risk of developing neurological complications remains relatively high among patients with HIV. Thus, the 2030 HIV vision must focus on further preventive measures to protect HIV patients from developing such neurological complications.

An HIV-1 Positive Woman Without Usual Immunodeficiency

Introduction: Acquired immune deficiency syndrome (AIDS) inflicts severe damage to the immune system. It transmits from one person to another through blood transfusions and vertical and sexual transmission. It should be noted that almost all papers reporting AIDS emphasized that HIV led to immune deficiency. However, this study reported the first HIV-1 seropositive woman who had an active viral load of HIV-1 without any signs or CD4 lymphocyte count depletion. Case Presentation: This study, for the first time, reported a 46-year-old HIV-1 seropositive woman without any signs and symptoms diagnosed 31 years ago by laboratory tests. Also, it is noteworthy that the patient had not received regular therapeutics during the infection period. Our serologic tests showed an active seropositive patient without any CD4 depletion. The viral load of HIV-1 was 132967.2 u/L, which was quantified by a real-time PCR assay. Also, a CBC test was performed and showed no abnormal results. Conclusions: An untreated HIV-1 positive patient without immunodeficiency is a rare condition, and we found no report of it in the literature. This article reported an HIV-1 positive patient in whom the infection was confirmed several times using the real-time PCR method.

Long-term remission of AIDS-related primary central nervous system lymphoma in a patient under antiretroviral therapy: a case report and review of the literature

BACKGROUND

AIDS-related primary central nervous system lymphoma (AR-PCNSL) is an AIDS-defining disease that usually occurs when the CD4 count is less than 50 cells/μl. The frequency of the disease has substantially decreased in the era of highly active antiretroviral therapy (HAART). Prognosis is poor with rapid progression leading to death within 2-3 months if left untreated.

CASE DESCRIPTION

A 65 years old male presented to medical attention with gait disturbance, weight loss and slight left-sided hemiparesis. Human immunodeficiency virus infection was diagnosed with an initial CD4 count of 116 cells/µl and a viral load of 260,000 copies/ml. Magnetic resonance imaging of the brain revealed three brain lesions involving the right frontal lobe and the left parietal lobe, which on biopsy led to a diagnosis of AR-PCNSL. HAART was initiated with whole-brain radiotherapy (WBRT), and the patient declined systemic chemotherapy. Due to poor performance status, he was transferred to palliative care. Under HAART, he slowly recovered with normalization of CD4 count and undetectable viral load. Medical imaging showed complete remission (CR) of the brain lesions. At 3-year follow-up, the patient remains in CR, but presented mild neurocognitive dysfunction possibly secondary to WBRT.

CONCLUSION

Nowadays, treatment paradigm parallels that of primary central nervous system lymphoma in the immunocompetent population based on systemic chemotherapy (primarily high-dose intravenous methotrexate and steroids) in association with HAART. The role of WBRT is questionable because of late neurotoxic effects.

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.

Neurological Manifestations of Acquired Immunodeficiency Syndrome

Objectives 

To determine the neurological manifestations in AIDS patients with a recent diagnosis.

Materials and methods

A descriptive, retrospective study was carried out on 82 patients, admitted to the University Hospital in Curitiba for a period of 30 months, with positive serology for HIV, using the enzyme-linked immunosorbent assay (ELISA) method for diagnosis and confirmation.

Results

Of the 82 patients studied, 28 (34.1%) presented neurological manifestations; 16 were male (57.14%) and 12 female (42.85%). The age ranged from 22 to 79 years, with a median age of 35 years. Neurological manifestations were: headache (19.29%), motor deficit (19.29%), cranial nerve disorders (14.03%), epileptic seizures (10.52%), dementia (8.77%), coma (5.26%), ataxia (5.26%), mental confusion (5.26%), and tremor (3.5%). Cerebrovascular and neuroinfectious diseases (including neurotoxoplasmosis, bacterial and cryptococcal meningitis, and cerebral tuberculosis) were the most frequent diagnosis with 10 cases each (33.33%). Of the 28 patients, 10 (35.7%) died and 18 (64.28%) were discharged.

Conclusion

Based on the results found, it appears that one-third of AIDS patients with up to one year of diagnosis (34.14%) have some type of neurological manifestation, highlighting the importance of performing specific anamnesis and neurological examination in these patients.

Cerebellar Cryptococcoma in an Immunocompetent Adult: A Rare Occurrence Report of a Case and Review of Literature

This study reports a rare case of cryptococcoma of the brain and review the related literature. An intracranial lesion, in a healthy, middle-aged adult who underwent surgery with a preoperative diagnosis of neoplastic/metastatic lesion, which turned out to be cryptococcoma, is being reported. Histopathological examination revealed that this immunocompetent patient had cryptococcoma of the cerebellum. He responded to antifungal chemotherapy (amphotericin B initially for 2 weeks and later oral fluconazole for 10 weeks) very well. Occurrence of cryptococcomas in immunocompetent patients is rare and responds to antifungal chemotherapy very well. Only six cases (including this) have been reported in literature till now.

Establishment and characterisation of a stavudine (d4T)-induced rat model of antiretroviral toxic neuropathy (ATN) using behavioural and pharmacological methods

Human immuno-deficiency virus (HIV) associated sensory neuropathy (SN) is a frequent complication of HIV infection. It is extremely difficult to alleviate and hence the quality of life of affected individuals is severely and adversely impacted. Stavudine (d4T) is an antiretroviral drug that was widely used globally prior to 2010 and that is still used today in resource-limited settings. Its low cost and relatively good efficacy when included in antiretroviral dosing regimens means that there is a large population of patients with d4T-induced antiretroviral toxic neuropathy (ATN). As there are no FDA approved drugs for alleviating ATN, it is important to establish rodent models to probe the pathobiology and to identify potentially efficacious new drug treatments. In the model establishment phase, d4T administered intravenously at a cumulative dose of 375 mg/kg in male Wistar Han rats evoked temporal development of sustained mechanical allodynia in the hindpaws from day 10 to day 30 after initiation of d4T treatment. As this d4T dosing regimen was also well tolerated, it was used for ATN model induction for subsequent pharmacological profiling. Both gabapentin at 30-100 mg/kg and morphine at 0.3-2 mg/kg given subcutaneously produced dose-dependent relief of mechanical allodynia with estimated ED₅₀'s of 19 mg/kg and 0.4 mg/kg, respectively. In contrast, intraperitoneal administration of meloxicam or amitriptyline up to 30 mg/kg and 7 mg/kg, respectively, lacked efficacy. Our rat model of ATN is suitable for investigation of the pathophysiology of d4T-induced SN as well as for profiling novel molecules from analgesic drug discovery programs.

Common gene-network signature of different neurological disorders and their potential implications to neuroAIDS

The neurological complications of AIDS (neuroAIDS) during the infection of human immunodeficiency virus (HIV) are symptomized by non-specific, multifaceted neurological conditions and therefore, defining a specific diagnosis/treatment mechanism(s) for this neuro-complexity at the molecular level remains elusive. Using an in silico based integrated gene network analysis we discovered that HIV infection shares convergent gene networks with each of twelve neurological disorders selected in this study. Importantly, a common gene network was identified among HIV infection, Alzheimer's disease, Parkinson's disease, multiple sclerosis, and age macular degeneration. An mRNA microarray analysis in HIV-infected monocytes showed significant changes in the expression of several genes of this in silico derived common pathway which suggests the possible physiological relevance of this gene-circuit in driving neuroAIDS condition. Further, this unique gene network was compared with another in silico derived novel, convergent gene network which is shared by seven major neurological disorders (Alzheimer's disease, Parkinson's disease, Multiple Sclerosis, Age Macular Degeneration, Amyotrophic Lateral Sclerosis, Vascular Dementia, and Restless Leg Syndrome). These networks differed in their gene circuits; however, in large, they involved innate immunity signaling pathways, which suggests commonalities in the immunological basis of different neuropathogenesis. The common gene circuits reported here can provide a prospective platform to understand how gene-circuits belonging to other neuro-disorders may be convoluted during real-time neuroAIDS condition and it may elucidate the underlying-and so far unknown-genetic overlap between HIV infection and neuroAIDS risk. Also, it may lead to a new paradigm in understanding disease progression, identifying biomarkers, and developing therapies.

Autoimmune diseases and HIV infection: A cross-sectional study

To describe the clinical manifestations, treatments, prognosis, and prevalence of autoimmune diseases (ADs) in human immunodeficiency virus (HIV)-infected patients.All HIV-infected patients managed in the Infectious Diseases Department of the Lyon University Hospitals, France, between January 2003 and December 2013 and presenting an AD were retrospectively included.Thirty-six ADs were found among 5186 HIV-infected patients which represents a prevalence of 0.69% including immune thrombocytopenic purpura (n = 15), inflammatory myositis (IM) (n = 4), sarcoidosis (n = 4), Guillain-Barré syndrome (GBS) (n = 4), myasthenia gravis (n = 2), Graves' disease (n = 2), and 1 case of each following conditions: systemic lupus erythematosus, rheumatoid arthritis, autoimmune hepatitis, Hashimoto thyroiditis and autoimmune hemolytic anemia. One patient presented 2 ADs. Thirty patients were known to be HIV-infected when they developed an AD. The AD preceded HIV infection in 2 patients. GBS and HIV infection were diagnosed simultaneously in 3 cases. At AD diagnosis, CD4 T lymphocytes count were higher than 350/mm in 63% of patients, between 200 and 350/mm in 19% and less than 200/mm in 19%. Twenty patients benefited from immunosuppressant treatments, with a good tolerance.ADs during HIV infection are uncommon in this large French cohort. Immune thrombocytopenic purpura, sarcoidosis, IM, and GBS appear to be more frequent than in the general population. Immunosuppressant treatments seem to be effective and well tolerated.

Getting into the brain: Potential of nanotechnology in the management of NeuroAIDS

In spite of significant advances in antiretroviral (ARV) therapy, the elimination of human immunodeficiency virus (HIV) reservoirs from the periphery and the central nervous system (CNS) remains a formidable task. The incapability of ARV to go across the blood-brain barrier (BBB) after systemic administration makes the brain one of the dominant HIV reservoirs. Thus, screening, monitoring, and elimination of HIV reservoirs from the brain remain a clinically daunting and key task. The practice and investigation of nanomedicine possesses potentials for therapeutics against neuroAIDS. This review highlights the advancements in nanoscience and nanotechnology to design and develop specific size therapeutic cargo for efficient navigation across BBB so as to recognize and eradicate HIV brain reservoirs. Different navigation and drug release strategies, their biocompatibility and efficacy with related challenges and future prospects are also discussed. This review would be an excellent platform to understand nano-enable multidisciplinary research to formulate efficient nanomedicine for the management of neuroAIDS.

Cerebral phaeohyphomycosis by Fonsecaea monophora: Report in a patient with AIDS and a ring enhancing lesion

Fungal infections are infrequent causes of brain abscesses. Fonsecaea monophora is a dematiaceous fungus that appears to be neurotropic. We report a case of Fonsecaea monophora infection in a patient with acquired immunodeficiency syndrome, and review previous reports of brain abscesses by this organism.

A case of primary HIV type 1 and cytomegalovirus coinfection presenting with widespread clinical disease

Coinfection of HIV-1 and cytomegalovirus (CMV) may occur given the shared routes of transmission, and the clinical presentations of each process overlap. We present a case of acute HIV-1 and CMV coinfection presenting with an acute febrile illness complicated by meningitis, hepatitis, and retinopathy. This and other similar cases demonstrate the need to consider CMV coinfection in acute HIV-1 disease, particularly in situations with significant end-organ damage.

Towards nanomedicines for neuroAIDS

Although highly active antiretroviral therapy (HAART) has resulted in remarkable decline in the morbidity and mortality in AIDS patients, controlling HIV infections still remain a global health priority. HIV access to the CNS serves as the natural viral preserve because most antiretroviral (ARV) drugs possess inadequate or zero delivery across the brain barriers. Thus, development of target-specific, effective, safe, and controllable drug-delivery approach is an important health priority for global elimination of AIDS progression. Emergence of nanotechnology in medicine has shown exciting prospect for development of novel drug delivery systems to administer the desired therapeutic levels of ARV drugs in the CNS. Neuron-resuscitating and/or antidependence agents may also be delivered in the brain through nanocarriers to countercheck the rate of neuronal degradation during HIV infection. Several nanovehicles such as liposomes, dendrimers, polymeric nanoparticles, micelles, and solid lipid nanoparticles have been intensively explored. Recently, magnetic nanoparticles and monocytes/macrophages have also been used as carrier to improve the delivery of nanoformulated ARV drugs across the blood-brain barrier. Nevertheless, more rigorous research homework has to be elucidated to sort out the shortcomings that affect the target specificity, delivery, release, and/or bioavailability of desired amount of drugs for treatment of neuroAIDS.

Toxoplasmosis of the spinal cord in an immunocompromised patient: case report and review of the literature

We, herein, describe an HIV-positive patient with toxoplasmosis of the spinal cord. We also carried out a comprehensive literature review of this topic, with emphasis on the diagnostic tools and therapeutic approach.

CNS-immune reconstitution inflammatory syndrome in the setting of HIV infection, part 2: discussion of neuro-immune reconstitution inflammatory syndrome with and without other pathogens

SUMMARY

While the previous review of CNS-IRIS in the HIV-infected patient on highly active antiretroviral therapy (Part 1) dealt with an overview of the biology, pathology, and neurologic presentation of this condition and a discussion of the atypical imaging findings in PML-IRIS and cryptococcal meningitis-IRIS due to the robust inflammatory response, the current review (Part 2) discusses the imaging findings in other commonly encountered organisms seen in association with CNS-IRIS, namely, VZV, CMV, HIV, Candida organisms, Mycobacterium tuberculosis, and Toxoplasma gondii. Also described is the imaging appearance of CNS-IRIS when not associated with a particular organism. Recognition of these imaging findings will give credence to the diagnosis of CNS-IRIS and will allow the clinician to institute changes in medical management, if necessary, so that immune reconstitution and improved patient outcome can occur with time.

[Consensus statement of the National AIDS Plan Secretariat, Spanish Society of Emergency Medicine and AIDS Study Group of the Spanish Society of Infectious Diseases and Clinical Microbiology on Emergency and Human Immunodeficiency Virus Infection]

OBJECTIVE

Supporting non-HIV specialist professionals in the treatment of patients with urgent diseases resulting from HIV infection.

METHODS

These recommendations have been agreed by an expert panel from the National AIDS Plan Secretariat, the Spanish Society of Emergency Medicine, and the AIDS Study Group. A review has been made of the safety and efficacy results of clinical trials and cohort studies published in biomedical journals (PubMed and Embase) or presented at conferences. The strength of each recommendation (A, B, C) and the level of supporting evidence (I, II, III) are based on a modification of the criteria of the Infectious Diseases Society of America.

RESULTS

The data to be collected from the emergency medical history in order to recognize the patient at risk of HIV infection were specified. It stressed the basic knowledge of ART principles and its importance in terms of decline in morbidity and mortality of HIV+ patients and referring to the HIV specialist for follow-up, where appropriate, including drug interactions. Management of different emergency situations that may occur in patients with HIV infection is also mentioned.

CONCLUSIONS

The non-HIV specialist professional, will find the necessary tools to approach HIV patients with an emergency disease.

HIV-Associated Central Nervous System Disease in Patients Admitted at the Douala General Hospital between 2004 and 2009: A Retrospective Study

Background. Studies on HIV-associated central nervous system (CNS) diseases in Cameroon are rare. The aim of this study was to describe the clinical presentation, identify aetiological factors, and determine predictors of mortality in HIV patients with CNS disease. Methods. From January 1, 2004 and December 31, 2009, we did at the Douala General Hospital a clinical case note review of 672 admitted adult (age ≥ 18 years) HIV-1 patients, and 44.6% (300/672) of whom were diagnosed and treated for HIV-associated CNS disease. Results. The mean age of the study population was 38.1 ± 13.5 years, and median CD4 count was 49 cells/mm³ (interquartile range (QR): 17–90). The most common clinical presentations were headache (83%), focal signs (40.6%), and fever (37.7%). Toxoplasma encephalitis and cryptococcal meningitis were the leading aetiologies of HIV-associated CNS disease in 32.3% and 25% of patients, respectively. Overall mortality was 49%. Primary central nervous system lymphoma (PCNSL) and bacterial meningitis had the highest case fatality rates of 100% followed by tuberculous meningitis (79.8%). Low CD4 count was an independent predictor of fatality (AOR: 3.2, 95%CI: 2.0–5.2). Conclusions. HIV-associated CNS disease is common in Douala. CNS symptoms in HIV patients need urgent investigation because of their association with diseases of high case fatality.

Toxoplasma gondii: the effect of fluconazole combined with sulfadiazine and pyrimethamine against acute toxoplasmosis in murine model

Toxoplasma gondii is an important opportunistic pathogen for immunocompromised patients and responsible for toxoplasmic encephalitis, which is often lethal. Treatment for this infection is limited to a restricted therapeutic arsenal. In this work we tested the combination of fluconazole with the current treatment for acute toxoplasmosis on the murine model in vivo. Different experimental groups were treated with combinations of sulfadiazine plus pyrimethamine with fluconazole and pyrimethamine with fluconazole. Fluconazole is an important antifungal triazole used against others CNS related opportunistic pathogens such as Cryptococcus neoformans and Candida spp. The combinations of fluconazole plus sulfadiazine and pyrimethamine or fluconazole plus pyrimethamine were remarkably effective against T. gondii in vivo. The 10-day treatment with 10mg/kg/day of fluconazole combined with 40/1mg/kg/day sulfadiazine and pyrimethamine resulted in 93% survival of CF1 mice acutely infected with the highly virulent T. gondii RH strain, versus 36% of mice treated with just sulfadiazine and pyrimethamine. Combinations of fluconazole with lower doses of sulfadiazine and pyrimethamine or with just pyrimethamine were also efficient in reducing the mortality of mice compared with the treatment without fluconazole. The results obtained are promising for the treatment of human toxoplasmosis and point to the need to extend these studies to other murine models.

Guillain-Barré Syndrome Associated with Primary Parvovirus B19 Infection in an HIV-1-Infected Patient

Parvovirus B19 (B19V) infection has rarely been reported as responsible for Guillain-Barré syndrome (GBS). We present the case of a 63-year-old man with AIDS who presented with rapidly progressing weakness of his inferior limbs and a newly appeared pancytopenia. CSF examination and electromyography were characteristic for GBS. Very high CSF and serum B19V DNA concentrations were present, in the absence of IgG or IgM against B19V. The neurologic and hematologic abnormalities improved after a 5-day course of i.v. immunoglobulins in parallel with a dramatic decrease in the B19V viral load.

CNS-immune reconstitution inflammatory syndrome in the setting of HIV infection, part 1: overview and discussion of progressive multifocal leukoencephalopathy-immune reconstitution inflammatory syndrome and cryptococcal-immune reconstitution inflammatory syndrome

SUMMARY

While uncommon, CNS-IRIS developing after the initiation of HAART in the setting of HIV-related severe immunosuppression is characterized by an intense inflammatory reaction to dead or latent organisms or to self-antigens due to a heightened but dysregulated immune response. While this reaction can range from mild to fulminating, encompassing a very wide clinical spectrum, it is important to recognize because changes in medical management may be necessary to prevent neurologic decline and even death. Once contained, however, this inflammatory response can be associated with improved patient outcome as immune function is restored. Among the infectious organisms that are most commonly associated with CNS-IRIS are the JC virus and Cryptococcus organisms, which will be the subject of this review. CD8 cell infiltration in the leptomeninges, perivascular spaces, blood vessels, and even parenchyma seems to be the pathologic hallmark of CNS-IRIS. While recognition of CNS-IRIS may be difficult, the onset of new or progressive clinical symptoms, despite medical therapy and despite improved laboratory data, and the appearance on neuroimaging studies of contrast enhancement, interstitial edema, mass effect, and restricted diffusion in infections not typically characterized by these findings in the untreated HIV-infected patient should raise the strong suspicion for CNS-IRIS. While CNS-IRIS is a diagnosis of exclusion, the neuroradiologist can play a critical role in alerting the clinician to the possibility of this syndrome.

Influence of antipsychotic drugs on human endogenous retrovirus (HERV) transcription in brain cells

Human endogenous retroviruses (HERVs) have been associated with various neurological and neuropsychiatric disorders. Transcripts and proteins of at least three HERV groups, HERV-W, ERV9 and HERV-K(HML-2) have been detected repeatedly in brain samples or cerebrospinal fluid of patients with schizophrenia suggesting that alterations in HERV activity may play a role in etiopathogenesis. Current therapies otherwise include neuroleptics and/or antidepressants that may induce epigenetic alterations and thus influence HERV expression. To investigate the effects of these drugs on HERV transcriptional activity, HERV expression profiles of a broad range of human brain cell lines treated with valproic acid (VPA), haloperidol, risperidone, and clozapine were analyzed using a retrovirus-specific microarray and qRT-PCR. Investigation of 52 HERV subgroups revealed upregulation of several class I and class II HERV elements by VPA in a dose-dependent manner. The strongest effect was observed on HERV-W and ERV9 groups in the human glioblastoma cell lines SK-N-SH and SK-N-MC, respectively. The transcript level of HERV-K(HML-2) elements was not influenced. Transcription of HERV-W, ERV9 and HERV-K(HML-2) taxa was further quantified in postmortem brain samples of patients with schizophrenia, bipolar disorders and a healthy control group with regard to their medication. Patients with schizophrenia showed a significantly higher HERV-W transcription associated with VPA treatment. However in case of ERV9, enhanced transcript levels could not be explained solely by VPA treatment, since a slight increase was also found in untreated patients compared to healthy controls. HERV-K(HML-2) elements appeared to be upregulated in some patients with bipolar disorders independent from medication. In conclusion, these results suggest that antipsychotic medication may contribute to increased expression of distinct HERV taxa in patients with neuropsychiatric diseases.

Nanoparticle-mediated targeted delivery of antiretrovirals to the brain

Nanotechnology offers a new platform for therapeutic delivery of antiretrovirals to the central nervous system (CNS) where human immunodeficiency virus (HIV-1) is sequestered in patients with HIV-1-associated neurological disorders (HAND). HAND is a spectrum of neurocognitive disorders that continue to persist in HIV-1-infected patients in spite of successful highly active antiretroviral therapy (HAART). Nanoformulated antiretroviral drugs offer multifunctionality, that is, the ability to package multiple diagnostic and therapeutic agents within the same nanocomposite, along with the added provisions of site-directed delivery, delivery across the blood-brain barrier (BBB), and controlled release of therapeutics. We have stably incorporated the antiretroviral drug, Amprenavir, within a transferrin (Tf)-conjugated quantum dot (QD), and evaluated the transversing ability of this Tf-QD-Amprenavir nanoplex across an in vitro BBB model and analyzed its antiviral efficacy in HIV-1-infected monocytes. We describe methods for synthesis of the Tf-QD-Amprenavir nanoplex and approaches to evaluate both its BBB transversing capability and antiviral efficacy.

CNS diseases and uveitis

A number of inflammatory, infectious, neoplastic and idiopathic disorders affect the eye and the central nervous system (CNS) concurrently or at different time frames. These conditions pose a diagnostic challenge to the clinician since they may present with similar ocular and neurological manifestations. The purpose of this review is to describe major neurological syndromes including multiple sclerosis, Vogt-Koyanagi-Harada disease, other autoimmune syndromes, and several infectious diseases which may affect the eye. This article may serve as a guide for the diagnosis and treatment of such disorders. It should be noted that these conditions have been viewed from a neurologist's perspective thereby neurologic involvement is stressed.

HIV-1 Tat activates indoleamine 2,3 dioxygenase in murine organotypic hippocampal slice cultures in a p38 mitogen-activated protein kinase-dependent manner

Background

We have established that activation of the tryptophan degrading enzyme indoleamine 2,3 dioxygenase (IDO) mediates the switch from cytokine-induced sickness behavior to depressive-like behavior. Because human immunodeficiency virus type 1 (HIV-1) Tat protein causes depressive-like behavior in mice, we investigated its ability to activate IDO in organotypic hippocampal slice cultures (OHSCs) derived from neonatal C57BL/6 mice.

Methods

Depressive-like behavior in C57BL/6J mice was assessed by the forced swim test. Expression of cytokines and IDO mRNA in OHSCs was measured by real-time RT-PCR and cytokine protein was measured by enzyme-linked immunosorbent assays (ELISAs). p38 MAPK phosphorylation was analyzed by western blot.

Results

Intracerebroventricular (i.c.v.) administration of Tat (40 ng) induced depressive-like behavior in the absence of sickness. Addition of Tat (40 ng/slice) to the medium of OHSCs induced IDO steady-state mRNA that peaked at 6 h. This effect was potentiated by pretreatment with IFNγ. Tat also induced the synthesis and release of TNFα and IL-6 protein in the supernatant of the slices and increased expression of the inducible isoform of nitric oxide synthase (iNOS) and the serotonin transporter (SERT). Tat had no effect on endogenous synthesis of IFNγ. To explore the mechanisms of Tat-induced IDO expression, slices were pretreated with the p38 mitogen-activated protein kinase (MAPK) inhibitor SB 202190 for 30 min before Tat treatment. SB 202190 significantly decreased IDO expression induced by Tat, and this effect was accompanied by a reduction of Tat-induced expression of TNFα, IL-6, iNOS and SERT.

Conclusion

These data establish that Tat induces IDO expression via an IFNγ-independent mechanism that depends upon activation of p38 MAPK. Targeting IDO itself or the p38 MAPK signaling pathway could provide a novel therapy for comorbid depressive disorders in HIV-1-infected patients.

Neurodegenerative effects of recombinant HIV-1 Tat(1-86) are associated with inhibition of microtubule formation and oxidative stress-related reductions in microtubule-associated protein-2(a,b)

The human immunodeficiency virus 1 (HIV-1) protein Trans-activator of Transcription (Tat) is a nuclear regulatory protein that may contribute to the development of HIV-1 associated dementia by disrupting the neuronal cytoskeleton. The present studies examined effects of recombinant Tat(1-86; 1-100 nM) on microtubule-associated protein (MAP)-dependent and MAP-independent microtubule formation ex vivo and oxidative neuronal injury in rat organotypic hippocampal explants. Acute exposure to Tat(1-86) (≥1 nM) markedly reduced MAP-dependent and -independent microtubule formation ex vivo, as did vincristine sulfate (0.1-10 μM). Cytotoxicity, as measured by propidium iodide uptake, was observed in granule cells of the DG with exposure to 100 nM Tat(1-86) for 24 or 72 h, while significant reductions in MAP-2 immunoreactivity were observed in granule cells and pyramidal cells of the CA1 and CA3 regions at each timepoint. These effects were prevented by co-exposure to the soluble vitamin E analog Trolox (500 μM). Thus, effects of Tat(1-86) on the neuronal viability may be associated with direct interactions with microtubules and generation of oxidative stress.

Inhibition of Nipah virus infection in vivo: targeting an early stage of paramyxovirus fusion activation during viral entry

In the paramyxovirus cell entry process, receptor binding triggers conformational changes in the fusion protein (F) leading to viral and cellular membrane fusion. Peptides derived from C-terminal heptad repeat (HRC) regions in F have been shown to inhibit fusion by preventing formation of the fusogenic six-helix bundle. We recently showed that the addition of a cholesterol group to HRC peptides active against Nipah virus targets these peptides to the membrane where fusion occurs, dramatically increasing their antiviral effect. In this work, we report that unlike the untagged HRC peptides, which bind to the postulated extended intermediate state bridging the viral and cell membranes, the cholesterol tagged HRC-derived peptides interact with F before the fusion peptide inserts into the target cell membrane, thus capturing an earlier stage in the F-activation process. Furthermore, we show that cholesterol tagging renders these peptides active in vivo: the cholesterol-tagged peptides cross the blood brain barrier, and effectively prevent and treat in an established animal model what would otherwise be fatal Nipah virus encephalitis. The in vivo efficacy of cholesterol-tagged peptides, and in particular their ability to penetrate the CNS, suggests that they are promising candidates for the prevention or therapy of infection by Nipah and other lethal paramyxoviruses.

Could differential virological characteristics account for ongoing viral replication and insidious damage of the brain during HIV 1 infection of the central nervous system?

Neurocognitive disorders due to human immunodeficiency virus type 1 (HIV-1) infection have been reported in 25-60% of cases,(1-3) despite a sustained viral response in peripheral blood while on highly active anti-retroviral therapy (HAART). A possible reason may be that the central nervous system (CNS) is less accessible for anti-retroviral agents, therefore this sanctuary site can provide a reservoir for ongoing HIV-1 replication. Mutations conferring resistance to anti-retroviral drugs may predominate in compartments where drug levels are suboptimal. This review provides an overview on the literature regarding the development of resistance mutations and the sensitivity for co-receptors in CNS. Mutations caused by the anti-retroviral drugs with the lowest intracerebral penetration would be expected to be found in higher percentages in the CNS than in the periphery of the human body. However, few studies have been performed that can confirm or reject this claim. Zidovudine, the anti-retroviral drug with the best intracerebral penetration, has been studied to some extent. This drug indeed induces resistance mutations in blood as well as the CNS. HAART induces a switch from HIV that uses co-receptor CRR5 to HIV that uses co-receptor CXCR4. This switch may appear later in the CNS compartment compared to the periphery. However, current literature shows conflicting evidence. In conclusion, the current understanding of HIV-strain evolution under drug pressure in sanctuary sites like CNS is incomplete. Therefore, more research is needed in order to establish the role of these sites in the development of drug resistant mutants under adequate HAART.