Neurological complications of acquired immune deficiency syndrome: analysis of 50 patients

HIV-related neurocognitive impairment--a review

Neurocognitive impairments following central nervous system opportunistic infections and HIV-associated dementia (HAD) were common clinical features of HIV infection prior to anti-retroviral therapy. As HIV infection has evolved from an invariably fatal disease with a poor prognosis to a condition requiring long-term management, HIV-related neurocognitive disorders have been the subject of increasing research. This review will examine the recent changes in the understanding of the HIV-associated neurocognitive disorders (HAND) including the changing epidemiology, risk factors associated with its development, methods for screening for the disorders and evolving treatment options.

Candida pelliculosa meningitis as an opportunistic infection in HIV: the first reported case

We describe the first reported case of Candida pelliculosa meningitis in HIV infection. This case highlights the risk of uncommon opportunistic infections in association with the immunocompromised and the importance of autopsy as a diagnostic tool in HIV infection. We discuss the epidemiology, diagnosis and management of C. pelliculosa, a non-albicans species which is rarely associated with disease, and review current literature.

Progressive multifocal leukoencephalopathy and newer biological agents

Progressive multifocal leukoencephalopathy (PML) is a rare demyelinating disease of the brain due to a polyoma virus, JC virus. Despite the ubiquity of this virus, PML is rare and almost always seen in association with an underlying immunosuppressive condition. In the last 30 years, AIDS has been the most common predisposing factor. The observation of PML attending the use of certain monoclonal antibody therapies and other pharmacological agents has raised concerns about the safety profile of these agents, but has also provided a window into the pathogenesis of PML. Certain agents, such as the monoclonal antibodies natalizumab, an α4β1 and α4β7 integrin inhibitor, and efalizumab, an antibody directed against CD11a, appear to uniquely predispose to PML. Prior to their introduction for multiple sclerosis and Crohn's disease with respect to natalizumab, and psoriasis with respect to efalizumab, PML had never been observed with these disorders. PML occurring with other agents that currently carry US FDA-mandated 'black-box' warnings, such as rituximab, an antibody directed to CD20, or mycophenolate mofetil, a drug that inhibits T- and B-cell proliferation, typically occur in the background of underlying disorders that have already been identified as risks for PML. This review will focus on the available data regarding the risk for PML with monoclonal antibodies and other drugs. A biologically plausible explanation for the increased risk of PML will be proposed, as well as potential strategies for mitigating disease risk.

Urologic aspects of HIV infection

Although lifespan has dramatically improved in the human immunodeficiency virus-positive (HIV+) population, HIV and its treatment continue to be a source of substantial morbidity in many organ systems, including the genitourinary tract. As the number of long-term survivors increases with advances in antiretroviral therapy, age-associated urologic symptoms are also becoming increasingly relevant considerations for people living with HIV. Primary care physicians have a major role to play in maintaining the genitourinary health of their HIV+ patients. This role is of great importance not just for the well-being of the individual patient but for the public health, as the genitourinary tract is a common vector for HIV transmission. In this article the authors review the management of the genitourinary system in patients with HIV infection. Particular consideration is given to urinary tract infections, lower urinary tract symptoms, renal insufficiency, sexual and fertility problems, and cancers of the genitourinary tract. Management algorithms are outlined and indications for referral to a urologist are emphasized.

Monoclonal antibodies and progressive multifocal leukoencephalopathy

Since their introduction, monoclonal antibodies have found an ever expanding role in the treatment of a wide number of disorders. However, the perturbation of the immune system that attends their use may also increase the risk for the development of disorders that arise in the setting of immunosuppressive conditions, such as, opportunistic infection and malignancy. In this paper, we address the association between some monoclonal antibodies and the development of a rare demyelinating disease of the brain, progressive multifocal leukoencephalopathy (PML). PML results from infection with a ubiquitous polyoma virus, JC virus, and typically occurs in the setting of impaired immunity, most commonly, AIDS. It was first recognized as a potential complication of monoclonal antibody therapy in patients with multiple sclerosis and Crohn disease being treated with natalizumab, an alpha 4 beta1 and alpha 4 beta 7 integrin inhibitor. Subsequently, efalizumab, a monoclonal antibody used in the treatment of psoriasis, was also demonstrated to be associated with PML. An increased risk has been suggested for rituximab, although most of the patients developing PML with that monoclonal antibody have been treated for B-cell disorders that predispose to the development of PML. Based on our current understanding of the biology of JC virus and the pathogenesis of PML, we propose an explanation for the increased risk for PML that is observed with natalizumab and certain other monoclonal antibodies.

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).

Encephalitis, acute renal failure, and acute hepatitis triggered by a viral infection in an immunocompetent young adult: a case report

INTRODUCTION

Cytomegalovirus generally causes self-limited, mild and asymptomatic infections in immunocompetent patients. An aggressive course in immunocompetent healthy patients is unusual.

CASE PRESENTATION

We report the case of an immunocompetent 16-year-old Egyptian boy with encephalitis, acute renal failure, and acute hepatitis triggered by viral infection with a complete recovery following antiviral treatment.

CONCLUSION

We believe that this case adds to the understanding of the molecular biology, clinical presentation and increasing index of suspicion of many viral infections.

HIV-related neurocognitive impairment in the HAART era

Neurocognitive impairment is common in people living with HIV and AIDS. Prior to highly active antiretroviral therapy (HAART), cognitive impairment primarily affected patients with advanced disease, and was a more rapidly progressive illness. With the use of HAART, cognitive impairment improved, along with the overall health of HIV-positive patients. However, it is still a prevalent problem, even in patients with desirable CD4+ count and undetectable plasma viral load. In this review, we address the nature of HIV-related neurocognitive impairment in the HAART era, including its etiology, pathology, appropriate diagnostic tools for clinical practice and research, and rational treatment approaches.

Cognitive neuropsychology of HIV-associated neurocognitive disorders

Advances in the treatment of the human immunodeficiency virus (HIV) have dramatically improved survival rates over the past 10 years, but HIV-associated neurocognitive disorders (HAND) remain highly prevalent and continue to represent a significant public health problem. This review provides an update on the nature, extent, and diagnosis of HAND. Particular emphasis is placed on critically evaluating research within the realm of cognitive neuropsychology that aims to elucidate the component processes of HAND across the domains of executive functions, motor skills, speeded information processing, episodic memory, attention/working memory, language, and visuoperception. In addition to clarifying the cognitive mechanisms of HAND (e.g., impaired cognitive control), the cognitive neuropsychology approach may enhance the ecological validity of neuroAIDS research and inform the development of much needed novel, targeted cognitive and behavioral therapies.

Spinal epidural cavernous hemangioma in an HIV-positive patient

BACKGROUND

Spinal epidural cavernous hemangioma is rare.

PURPOSE

Here, we report a case of spinal epidural cavernous hemangioma in an HIV-positive patient.

STUDY DESIGN

Single case report.

METHOD

A 40-year-old known HIV-positive woman presented with a 6-month history of slowly progressive bilateral leg weakness and pain. Neuroimaging showed an epidural mass lesion, which was isointense on T1-WI, hyperintense on T2-WI, and homogenously enhanced with gadolinium diethylenetriamine pentaacetate (Gd-DTPA), from T8 to T10.

RESULTS

The patient underwent T8-T10 laminectomy and removal of this lesion. Pathological diagnosis was cavernous hemangioma.

CONCLUSION

Although soft-tissue tumors such as Kaposi's sarcoma and lymphomas have been well documented in association with HIV infection, this is the first reported case of spinal epidural cavernous hemangioma. This may be an incidental finding or perhaps a causal relationship exists, suggesting that cavernous hemangioma could be a differential diagnosis of a spine lesion in HIV-positive patients.

Cytokine and chemokine regulation of sensory neuron function

Pain normally subserves a vital role in the survival of the organism, prompting the avoidance of situations associated with tissue damage. However, the sensation of pain can become dissociated from its normal physiological role. In conditions of neuropathic pain, spontaneous or hypersensitive pain behavior occurs in the absence of the appropriate stimuli. Our incomplete understanding of the mechanisms underlying chronic pain hypersensitivity accounts for the general ineffectiveness of currently available options for the treatment of chronic pain syndromes. Despite its complex pathophysiological nature, it is clear that neuropathic pain is associated with short- and long-term changes in the excitability of sensory neurons in the dorsal root ganglia (DRG) as well as their central connections. Recent evidence suggests that the upregulated expression of inflammatory cytokines in association with tissue damage or infection triggers the observed hyperexcitability of pain sensory neurons. The actions of inflammatory cytokines synthesized by DRG neurons and associated glial cells, as well as by astrocytes and microglia in the spinal cord, can produce changes in the excitability of nociceptive sensory neurons. These changes include rapid alterations in the properties of ion channels expressed by these neurons, as well as longer-term changes resulting from new gene transcription. In this chapter we review the diverse changes produced by inflammatory cytokines in the behavior of sensory neurons in the context of chronic pain syndromes.

Antiretroviral therapy and central nervous system HIV type 1 infection

Central nervous system (CNS) human immunodeficiency virus type 1 (HIV-1) infection begins during primary viremia and continues throughout the course of untreated systemic infection. Although frequently accompanied by local inflammatory reactions detectable in cerebrospinal fluid (CSF), CNS HIV-1 infection usually is not clinically apparent. In a minority of patients, CNS HIV-1 infection evolves into encephalitis during the late stages of systemic infection, which compromises brain function and presents clinically as acquired immunodeficiency syndrome dementia complex (ADC). Combination antiretroviral therapy (ART) has had a major impact on all aspects of CNS HIV-1 infection and disease. In those with asymptomatic infection, ART usually effectively suppresses HIV-1 in CSF and markedly reduces the incidence of symptomatic ADC. In those presenting with ADC, ART characteristically prevents neurological progression and leads to variable, and at times substantial, recovery. Similarly, treatment has reduced CNS opportunistic infections. With better control of these severe disorders, attention has turned to the possible consequences of chronic silent infection and the issue of whether indolent, low-grade brain injury might require earlier treatment intervention.

Aging sensitizes mice to behavioral deficits induced by central HIV-1 gp120

The number of older adults with HIV-1 disease is increasing but little is known about how age influences behavioral deficits associated with HIV-1 infection. The purpose of this study was to determine in a murine model if aging influenced sickness behavior following central injection of HIV-1 gp120. In initial studies, behavioral deficits induced by acute and repeated intracerebroventricular (ICV) injection of gp120 were greater in aged mice than in adults. Furthermore, repeated ICV injection of gp120 increased hippocampal levels of IL-1 beta and IL-6 mRNA in aged mice but not in adults. To determine if IL-6, which is elevated in aged brain, affects expression of the gp120-binding target, CCR5, microglia (BV-2 cell line) were incubated with increasing concentrations of IL-6. Cell surface expression of CCR5 was increased by IL-6 in a dose-dependent manner. Additionally, IL-6 increased gp120-dependent chemotaxis. These results suggest that aging increases the sensitivity of mice to behavioral deficits caused by ICV gp120, perhaps by increasing expression of CCR5 and augmenting production of cytokines.

Otoneurological findings in human immunodeficiency virus positive patients

OBJECTIVE

To investigate vestibular function in human immunodeficiency virus positive subjects.

METHODS

We studied vestibular function in 60 human immunodeficiency virus positive subjects reporting dizziness. All three Center for Disease Control and Prevention categories of human immunodeficiency virus infection were represented in the study group (30 patients in class A, 20 in class B and 10 in class C). Subjects had had no previous history of acute vertigo. All subjects underwent: neurotological screening for spontaneous, positional and positioning nystagmus, using head-shaking and head-thrust (Halmagyi) tests; audiometrical examination; and electronystagmography with bithermal stimulation (Freyss' method). The results of the 30 class A subjects were compared with those of 30 human immunodeficiency virus negative patients reporting dizziness.

RESULTS

Abnormal otoneurological findings increased progressively from the A to C categories, particularly regarding increased central damage (3.3 per cent of class A, 35 per cent of class B and 100 per cent of class C subjects). In contrast, the incidence of peripheral vestibular disorders remained almost the same, comparing the three categories (33.3 per cent in class A and 50 per cent in classes B and C subjects). Moreover, a higher number of human immunodeficiency virus positive subjects showed abnormal otoneurological findings, compared with the dizzy, human immunodeficiency virus negative subjects.

CONCLUSIONS

In our opinion, a vestibular disorder may occur in human immunodeficiency virus positive patients as a result of direct viral damage, even in the early phase of infection. Central vestibular damage may be established later on, and may be linked to different causes (e.g. superinfections, vascular causes and drug toxicity).

CB2 receptors in the brain: role in central immune function

Recently, it has been recognized that the cannabinoid receptor CB2 may play a functionally relevant role in the central nervous system (CNS). This role is mediated primarily through microglia, a resident population of cells in the CNS that is morphologically, phenotypically, and functionally related to macrophages. These cells also express the cannabinoid receptor CB1. The CB1 receptor (CB1R) is constitutively expressed at low levels while the CB2 receptor (CB2R) is expressed at higher levels and is modulated in relation to cell activation state. The relatively high levels of the CB2R correspond with microglia being in 'responsive' and 'primed' states, suggesting the existence of a 'window' of functional relevance during which activation of the CB2R modulates microglial activities. Signature activities of 'responsive' and 'primed' microglia are chemotaxis and antigen processing, respectively. The endocannabinoid 2-arachidonylglycerol has been reported to stimulate a chemotactic response from these cells through the CB2R. In contrast, we have shown in vivo and in vitro that the exogenous cannabinoids delta-9-tetrahydrocannabinol and CP55940 inhibit the chemotactic response of microglia to Acanthamoeba culbertsoni, an opportunistic pathogen that is the causative agent of Granulomatous Amoebic Encephalitis, through activation of the CB2R. It is postulated that these exogenous cannabinoids superimpose an inhibitory effect on pro-chemotactic endocannabinoids that are elicited in response to Acanthamoeba. Furthermore, the collective results suggest that the CB2R plays a critical immune functional role in the CNS.

Chemokines and the pathophysiology of neuropathic pain

Chemokines and chemokine receptors are widely expressed by cells of the immune and nervous systems. This review focuses on our current knowledge concerning the role of chemokines in the pathophysiology of chronic pain syndromes. Injury- or disease-induced changes in the expression of diverse chemokines and their receptors have been demonstrated in the neural and nonneural elements of pain pathways. Under these circumstances, chemokines have been shown to modulate the electrical activity of neurons by multiple regulatory pathways including increases in neurotransmitter release through Ca-dependent mechanisms and transactivation of transient receptor channels. Either of these mechanisms alone, or in combination, may contribute to sustained excitability of primary afferent and secondary neurons within spinal pain pathways. Another manner in which chemokines may influence sustained neuronal excitability may be their ability to function as excitatory neurotransmitters within the peripheral and central nervous system. As is the case for traditional neurotransmitters, injury-induced up-regulated chemokines are found within synaptic vesicles. Chemokines released after depolarization of the cell membrane can then act on other chemokine receptor-bearing neurons, glia, or immune cells. Because up-regulation of chemokines and their receptors may be one of the mechanisms that directly or indirectly contribute to the development and maintenance of chronic pain, these molecules may then represent novel targets for therapeutic intervention in chronic pain states.

Autonomic dysfunction in HIV patients on antiretroviral therapy: studies of heart rate variability

BACKGROUND

The presence of autonomic dysfunction in HIV patients is largely unknown. Early studies found autonomic dysfunction in patients with AIDS. Introduction of highly active antiretroviral combination therapy (ART) has dramatically changed the course of the disease and improved prognosis and decreased morbidity. At present it is not known whether introduction of ART also has decreased autonomic dysfunction.

AIM

To evaluate whether autonomic dysfunction is present in an ART-treated HIV population.

METHODS

HIV patients receiving ART for at least 3 years (n = 16) and an age-matched control group of healthy volunteers (n = 12) were included. All were non-smokers, non-diabetic and had never received medication for dyslipidaemia or hypertension. Following a 10 min resting period a 5 min ECG recording was performed. Heart rate variability (HRV) analysis was performed in accordance with current guidelines and data reported as median (interquartile range).

RESULTS

The resting heart rate was higher in HIV patients compared with controls [69 (62-74) versus 57 (52-60); P<0.001]. Total HRV measured as standard deviation of normal-to-normal (SONN) was lower in the HIV group compared with the controls [36 (25-55) versus 74 (57-84) ms; P<0.01] as was parasympathetic activity measured as square root of the mean squared difference of successive normal-to-normal intervals (RMSSD) [22 (9-30) versus 35 (24-62) ms; P<0.05]. Low frequency power was lower in the HIV group compared with the control group [294 (161-602) versus 946 (711-1668) ms(2); P<0.01]. High frequency power as well as systolic and diastolic blood pressure did not differ between the groups.

CONCLUSIONS

The HIV patients in ART have increased resting heart rate and decreased short-term heart rate variability indicating parasympathetic dysfunction.

Neuropathologic contributions to understanding AIDS and the central nervous system

This historical review describes the evolution of the pathogenetic concepts associated with infection by the Human Immunodeficiency Virus (HIV), with emphasis on the pathology of the nervous system. Although the first descriptions of damage to the nervous system in the acquired immunodeficiency syndrome (AIDS) only appeared in 1982, the dramatic diffusion of the epidemic worldwide and the invariably rapidly fatal outcome of the disease, before the introduction of efficient treatment, generated from the beginning an enormous amount of research with rethinking on a number of pathogenetic concepts. Less than 25 years after the first autopsy series of AIDS patients were published and the virus responsible for AIDS was identified, satisfactory definition and classification of a number of neuropathological complications of HIV infection have been established, leading to accurate clinical radiological and biological diagnosis of the main neurological complications of the disease, which remain a major cause of disability and death in AIDS patients. Clinical and experimental studies have provided essential insight into the pathogenesis of CNS lesions and natural history of the disease. The relatively recent introduction of highly active antiretroviral therapy (HAART) in 1995-1996 has dramatically improved the course and prognosis of HIV disease. However, there remain a number of unsolved pathogenetic issues, the most puzzling of which remains the precise mechanism of neuronal damage underlying the specific HIV-related cognitive disorders (HIV dementia). In addition, although HAART has changed the course of neurological complications of HIV infection, new issues have emerged such as the lack of improvement or even paradoxical deterioration of the neurological status in treated patients. Interpretation of these latter data remains largely speculative partly because of the small number of neuropathological studies related to the beneficial consequence of this treatment.

Regulation of topoisomerase II alpha and beta in HIV-1 infected and uninfected neuroblastoma and astrocytoma cells: involvement of distinct nordihydroguaretic acid sensitive inflammatory pathways

The activity of Topoisomerase II alpha and beta isoforms is tightly regulated during different phases of cell cycle. In the present study, the action of anti-inflammatory agents, nordihydroguaretic acid (NDGA) is analyzed in HIV-1 infected CXCR4(+), CCR5(+) and CD4(-) SK-N-SH neuroblastoma, CXCR4(+), CCR5(+) and CD4(-) 1321N1 astrocytoma and CXCR4(+), CCR5(+/-) and CD4(-) GO-G-CCM glioblastoma cell lines. In SK-N-SH and 1321N1 the expression of Topoisomerase II alpha is concomitant with that of LOX-5 and is highly sensitive to NDGA, while the Topoisomerase II beta is expressed along with TNFalpha and exhibits low sensitivity to NDGA, suggesting distinct pathways of regulation for the two isoforms. HIV-1 infection in these cells enhanced the expression of Topo II alpha and beta. Further, the regulation of Topo II beta and TNFalpha in infected and uninfected SK cells is distinctly different. HIV-1 gp120 derived peptides could block HIV-1 mediated inflammation and Topoisomerase II alpha and beta expression, suggesting the viral mediated response. A combination of NDGA, gp-120 derived peptides and AZT has completely blocked the viral replication, suggesting the enhancement of potency of AZT under the suppression of inflammatory response. In contrast, the expression of Topo II alpha and beta was stimulated by NDGA in GO-G-CCM cells showing distinct regulatory pathway in these cells that was resistant to HIV-1 infection. This suggests the requirement of inflammatory response for productive viral infection. In summary, an induction of co-receptor mediated inflammatory response can distinctly enhance regulated expression of the cellular Topo II alpha and beta and promote productive infection in neurons and astrocytes.

Infectious Neuropathies

Peripheral neuropathies can result from several infective agents, ranging from viruses, especially retroviruses, to parasites and bacilli. Leprosy, which often is considered a disorder of the past, still is common in dome geographic areas, especially in Africa, South America, and Asia. An increasing number of cases of neuropathies occurs in patients who have HIV or Lyme disease. The important point is that all these neuropathies are treatable and often preventable.

AIDS dementia complex in China

The AIDS dementia complex (ADC) is one of the most common neurological complications in patients with AIDS. However, little is known about the clinical features of ADC in China. We prospectively studied six patients with confirmed ADC out of a total of 36 AIDS patients treated from 1999 to 2003. All patients had short-term memory loss and poor concentration, with preserved alertness. Motor disability was identified in three patients. Of the six ADC patients, two had accompanying vacuolar myelopathy. All of the patients died, with a mean age at death of 41.8 years. The median survival of these ADC patients from the time of diagnosis was 4.7 months. In this context, we suggest that early diagnosis and highly active antiretroviral therapy treatment is an urgent priority in developing countries.

Infective Causes of Facial Nerve Paralysis

OBJECTIVE

To review the functional recovery in a cohort of patients with facial nerve paralysis (FNP) due to infective cause.

STUDY DESIGN

Retrospective review based on patients identified from a prospectively maintained database of patients with FNP. The case notes of identified patients were reviewed.

SETTING

Tertiary referral center.

PATIENTS

The patients were identified from a database of 1074 patients with FNP. One hundred twenty of the 150 patients identified as having FNP due to an infectious disease caused by herpes zoster oticus were excluded from the study. The remaining 30 patients were included in the study.

INTERVENTIONS

Patients were treated both operatively and nonoperatively. Operative treatment included myringotomy and ventilation tube placement, cortical mastoidectomy, modified radical (canal wall down) mastoidectomy, petrous apicectomy, and lateral temporal bone resection.

MAIN OUTCOME MEASURES

This study used the House-Brackmann (HB) grade of facial function at 1 year after initial assessment. The patients were identified from a prospectively maintained database of all patients presenting with FNP to a single specialist otolaryngologist (G.R.C.) between June 1988 and April 2005. The database contains information including demographic details, dates of presentation, diagnostic modalities used, diagnosis, interventions, and HB grade. The patients in this series presented between August 4, 1989 and August 26, 2003.

RESULTS

Twenty-nine patients with 30 facial nerve paralyses were identified. The causes of FNP were acute otitis media (n = 10); cholesteatoma (n = 10 [acquired, 7; congenital, 3]); mastoid cavity infections (n = 2); malignant otitis externa (n = 2); noncholesteatomatous chronic suppurative otitis media (CSOM; n = 2); tuberculous mastoiditis (n = 1); suppurative parotitis (n = 1); and chronic granulomatosis (n = 1). The patients with noncholesteatomatous CSOM who presented sooner after the onset of facial nerve symptoms had greater facial nerve recovery when assessed using the HB grade at 1 year.

CONCLUSION

FNP due to infective causes other than herpes zoster oticus is rare. Patients with noncholesteatomatous CSOM and FNP have a better outcome than those with FNP due to cholesteatoma. Patients with FNP due to acute otitis media tend to have a good prognosis without surgical decompression of the facial nerve being required.

Natalizumab and progressive multifocal leucoencephalopathy

Current data suggest that as many as 1 in 1000 treated individuals may develop progressive multifocal leucoencephalopathy (PML) in concert with the use of natalizumab. Natalizumab was withdrawn in early 2005. The present paper provides a comprehensive description of PML and reviews the role of natalizumab in the pathogenesis of PML. It is likely that use of drugs which cause specific perturbations of the immune system will be accompanied by similar rare infections. Thus researchers should be on the alert when using such agents in clinical trials.

Genetic markers on HIV-1 gp120 C2-V3 region associated with the expression or absence of cognitive motor complex in HIV/AIDS

In the CNS, HIV-1 causes cognitive motor complex (CMC) in about 30-40% of patients. To explain CMC physiopathology: disequilibrium of cytokine networks, calcium influx, free radicals and toxic effects by HIV-1 have been evoked. Neurotropic mutants have not been unambiguously proven nor 'variants' of HIV-1 with biological properties that could cause CMC. By computerized analysis of gp120 C2-V3 subtype B sequences from retroviral databases, and applying stringent criteria, we found: (i) mutations specific for CMC; (ii) mutations associated with the absence of CMC (N-CMC); (iii) mutations with specificity for the geographical region of origin, and finally (iv) shared mutations representing 'hot spots.' We suggest that the capability to cause or not to cause CMC may be present in the virus prior to infection. In the future, these markers could be used to guide treatments with novel neuroprotective regimes.

Affective disorders in patients with HIV infection: impact of antiretroviral therapy

At the beginning of the AIDS pandemic, affective disorders (such as depressed mood) were seen in a considerable number of HIV-1-infected individuals. These disorders were a result of the poor physical condition of the patients, brain involvement by the virus (e.g. encephalopathy) or a reaction to disadvantageous living conditions (losing friends, jobs, etc.). In the era of highly active antiretroviral therapy (HAART), mental illness related to physical weakness is declining, as is the incidence of HIV-1-associated encephalopathy. However, depressed mood and fatigue caused by efavirenz (a standard component of HAART) is becoming increasingly important, particularly in individuals who are infected long-term with HIV-1. Whatever the cause of affective disorders, their presence has been shown to negatively influence adherence to HAART and HIV-1 disease progression. Specialist knowledge of HIV-1 infection, and HAART and its psychiatric complications (particularly in subgroups of patients such as drug abusers and older people), is needed to care adequately for patients. Furthermore, prospective studies are needed to more fully differentiate between the various aetiologies of affective disorders seen in individuals living with HIV/AIDS and to determine their incidence and prevalence. Such information is important to ensure that affective disorders are recognised and adequately treated, which will in turn improve the efficacy of HAART.

Cerebral aneurysmal arteriopathy associated with HIV infection in an adult

Human immunodeficiency virus (HIV)-associated cerebral aneurysmal arteriopathy is described in the pediatric medical literature and features diffuse fusiform aneurysms of the arteries of the circle of Willis. We present the first report (to our knowledge) of this disease entity in an adult, a 29-year-old woman with acquired immunodeficiency syndrome who presented with subarachnoid hemorrhage.

Power spectral analysis of heart rate variability in HIV-infected and AIDS patients

BACKGROUND

In HIV-infected patients the risks for cardiovascular disease are multifactorial. Autonomic dysfunction has been detected in the early phase of HIV infection as well as in AIDS patients with advanced cardiomyopathy.

METHODS

Forty AIDS patients receiving highly active antiretroviral therapy (HAART), 40 HIV+ naïve of HAART, and 40 control subjects were studied. Computerized analysis of heart rate variability was performed using an analog to digital converter. R-R intervals were obtained from a standard ECG, recorded in DII lead in supine rest and after the cold-face and tilt tests. The series of R-R intervals were assessed in time and frequency domains using an autoregressive algorithm.

RESULTS

There was no difference regarding to mean values of R-R intervals and variance in baseline. The normalized power of the low-frequency (LF) component and the low-frequency/high-frequency (HF) ratio (LF/HF) was significantly decreased in the HIV group. Responses of normalized HF and LF/HF ratio during the cold-face test were significantly decreased in the HIV group, as compared to the control. During the tilt test, a higher augmentation of normalized LF and the LF/HF ratio was observed in the HIV group compared with the control. The AIDS group was similar to the control in baseline and after cold-face and tilt tests.

CONCLUSION

The HIV group presented in baseline conditions, a shift of cardiac sympathovagal balance, an exacerbated response of the LF component during the tilt test, and an ineffective cardiac vagal response to the cold-face test suggesting sympathetic and parasympathetic dysfunction. AIDS patients receiving HAART did not present these autonomic alterations.

Neurobiology of multiple insults: HIV-1-associated brain disorders in those who use illicit drugs

Despite two decades of research, certain aspects of HIV-related central nervous system (CNS) disease remain poorly understood. HIV targets microglia and macrophages within the CNS and enters the brain compartment early. However, HIV is there held in check apparently until the onset of significant immune compromise, when viral replication, microglial activation, neuronal damage, and cognitive impairment are likely to ensue. Illicit drug abuse continues to be a significant risk factor for HIV transmission worldwide. Whether HIV-related CNS disease is more prevalent or more severe in this risk group has long been debated. Drugs of abuse can of themselves cause immune suppression, blood-brain barrier breakdown, microglial activation, and neuronal injury. This review presents evidence that HIV associated CNS disorders are indeed accentuated in drug abusers. However, the advent of effective therapy has added a new dimension, which must be taken into consideration. Treated individuals are surviving much longer and HIV encephalitis and HIV-associated dementia have become much less common. However, more subtle forms of CNS damage are emerging. Examination of the brains of individuals who have been treated long term with highly active antiretroviral therapy (HAART) reveals a surprising degree of microglial activation, comparable at times to that seen formerly in milder cases of HIV encephalitis. In addition, these individuals show evidence of increased deposition of neurodegenerative proteins, particularly hyperphosphorylated tau. Similar observations have been made in young opiate abusers who are HIV negative. Taken together, these results suggest that neuroinflammation and neurodegeneration, which are clinically silent at present, may cause problems in the future in HAART-treated subjects.

Neuropsychological Impairment Among Asymptomatic HIV-Positive Former Intravenous Drug Users

OBJECTIVE

To evaluate the influence of human immunodeficiency virus (HIV) infection and situation of drug consumption on neuropsychological impairment in asymptomatic HIV-positive (HIV+) former intravenous drug users (IVDUs) of Spanish nationality.

BACKGROUND

Currently, we have no data about neuropsychological impairment in asymptomatic HIV+ IVDUs taking into account different situations of drug consumption.

METHOD

A neuropsychological evaluation was made of four groups of IVDUs: 33 abstinent HIV+ IVDUs, 21 methadone-maintained HIV+ IVDUs, 27 abstinent HIV-negative (HIV-) IVDUs, and 21 methadone-maintained HIV- IVDUs. Their neuropsychological impairment rates were determined taking as a reference the performance of 23 HIV- subjects without history of drug abuse.

RESULTS

The rate of neuropsychological impairment of methadone-maintained HIV+ patients (48%) and that of those in abstinence (24%) is greater than that of HIV- subjects in a similar condition (19% and 11%). The impairment rate of the methadone-maintained HIV+ group is significantly greater than that of the abstinent HIV+. Methadone-maintained HIV+ subjects with neuropsychological impairment have fewer education years than those not impaired; likewise, the percentages of subjects with significant immunodepression, detectable viral load, and without antiretroviral treatments are higher among methadone-maintained subjects with neuropsychological impairment.

CONCLUSIONS

This study emphasizes the association of asymptomatic HIV infection with neuropsychological impairment in IVDUs and reveals the importance of the drug consumption situation in relation to this risk, being methadone-maintained IVDUs more likely to suffer from it. This fact seems to be related to the worsening of the infection and its treatment and to educational level.

Progressive multifocal leukoencephalopathy: lessons from AIDS and natalizumab

The dramatic increase in the incidence of progressive multifocal leukoencephalopathy (PML) that occurred as a consequence of the AIDS pandemic and the recent association of PML with the administration of natalizumab, a monoclonal antibody to alpha4 integrin that blocks inflammatory cell entry into the brain, has stimulated a great deal of interest in this previously obscure viral demyelinating disease. The etiology of this disorder is JC virus (JCV), a polyoma virus, observed in 80% of the population worldwide. Seroepidemiological studies indicate that infection with this virus typically occurs before the age of 20 years. No primary illness owing to JCV infection has been recognized and the means of spread from person to person remains obscure. Following infection, the virus becomes latent in bone marrow, spleen, tonsils and other tissues. Periodically the virus reactivates during which time it can be demonstrated in circulating peripheral lymphocytes. The latter is significantly more commonly observed in immunosuppressed populations than that in normal subjects. Despite the large pool of people infected with JCV, PML remains a relatively rare disease. It is seldom observed in the absence of an underlying predisposing illness, typically one that results in impaired cellular immunity. A variety of factors are likely responsible for the unique increase in frequency of PML in HIV infection relative to other underling immunosuppressive disorders. Preliminary data suggests that natalizumab appears to distinctively predispose recipients to PML relative to other infectious complications. Studies in these populations will be invaluable in understanding the mechanisms of disease pathogenesis.

Neurological disease in HIV-infected patients in the era of highly active antiretroviral treatment: a Brazilian experience

To study characteristics of neurological disorders in HIV/AIDS patients and their relationship to highly active antiretroviral treatment, a cross-sectional study was conducted in an infectious disease public hospital in Belo Horizonte, Brazil, between February 1999 and March 2000. Of the 417 patients enrolled, neurological disease was observed in 194 (46.5%) and a new AIDS-defining neurological event developed in 23.7% of individuals. Toxoplasmosis (42.3%), cryptococcosis meningitis (12.9%) and tuberculosis (10.8%) were the most common causes of neurological complications. The majority (79.3%) of patients were on highly active antiretroviral treatment and these individuals using HAART showed higher CD4 cell counts (p = 0.014) and presented stable neurological disease (p= 0.0001), although no difference was found with respect to the profile of neurological complications. The neurological diseases continue to be a frequent complication of HIV/AIDS and infections are still its main causes in Brazil, even in the highly active antiretroviral treatment era.

AIDS-related malignancies: changing epidemiology and the impact of highly active antiretroviral therapy

PURPOSE OF REVIEW

Three cancers in people with HIV denote an AIDS diagnosis: Kaposi's sarcoma, high-grade B-cell non-Hodgkin's lymphoma and invasive cervical cancer. In addition a number of other cancers occur at increased frequency in this population group but are not AIDS-defining illnesses. This review discusses the impact of highly active antiretroviral therapy on the epidemiology and outcome of AIDS-defining cancers.

RECENT FINDINGS

The incidence of both Kaposi's sarcoma and non-Hodgkin's lymphoma has declined in the era of highly active antiretroviral therapy and the outcome of both tumours has improved. Moreover, highly active antiretroviral therapy alone produces a response in a majority of antiretroviral-naïve patients with Kaposi's sarcoma. In contrast, highly active antiretroviral therapy has had little impact on the incidence of human papilloma virus-associated tumours (cervical and anal cancer) in people with HIV, although it may improve survival by reducing opportunistic infection deaths. As people with HIV live longer with highly active antiretroviral therapy, an increased incidence of other non AIDS-defining cancers that have no known association with oncogenic infections is becoming apparent.

SUMMARY

For those with access to highly active antiretroviral therapy, the good news from the AIDS-defining cancers - particularly Kaposi's sarcoma and non-Hodgkin's lymphoma - may be balanced by the increasing numbers of non AIDS-defining cancers.

Neurological complications in AIDS patients receiving HAART: a 2-year retrospective study

The positive role of highly active anti-retroviral therapy (HAART) in reducing opportunistic infections in acquired immunodeficiency syndrome (AIDS) patients is well known. However, case reports from around the world have demonstrated that some patients seem to suffer a paradoxical deterioration of health as their immune function improves with treatment. This phenomenon has been called immune restoration inflammatory syndrome (IRIS). In northern Thailand, GPO-vir (Stavudine-D4T + Lamivudine-3TC + Nevirapine-NVP) has been promoted for the treatment of AIDS patients since April 2002, in accordance with the Government Pharmaceutical Organization's guidelines. However, the incidence rates of IRIS affecting nervous system (NIRIS) and non-NIRIS in comparison with the previous incidence of AIDS-defining disease have not been reported. We conducted a retrospective study to review the incidence of NIRIS and non-NIRIS in AIDS patients treated with GPO-vir in Chiang Mai University Hospital, Thailand, between May 2002 and April 2004. We compare these incidence rates with the incidence rates of neurological complications in the pre-HAART era. Altogether 506 AIDS patients were treated with GPO-vir during the specified period. The overall incidence of NIRIS, including progressive multifocal leukoencephalopathy (PML), cerebral toxoplasmosis and cytomegalovirus (CMV) retinitis, was lower than the previous incidence of AIDS-defining disease in the pre-HAART era. However, the incidence of ischemic stroke, hemorrhagic stroke and primary central nervous system (CNS) lymphoma had increased.

JC virus induces altered patterns of cellular gene expression: interferon-inducible genes as major transcriptional targets

Human polyomavirus JC (JCV) infects 80% of the population worldwide. Primary infection, typically occurring during childhood, is asymptomatic in immunocompetent individuals and results in lifelong latency and persistent infection. However, among the severely immunocompromised, JCV may cause a fatal demyelinating disease, progressive multifocal leukoencephalopathy (PML). Virus-host interactions influencing persistence and pathogenicity are not well understood, although significant regulation of JCV activity is thought to occur at the level of transcription. Regulation of the JCV early and late promoters during the lytic cycle is a complex event that requires participation of both viral and cellular factors. We have used cDNA microarray technology to analyze global alterations in gene expression in JCV-permissive primary human fetal glial cells (PHFG). Expression of more than 400 cellular genes was altered, including many that influence cell proliferation, cell communication and interferon (IFN)-mediated host defense responses. Genes in the latter category included signal transducer and activator of transcription 1 (STAT1), interferon stimulating gene 56 (ISG56), myxovirus resistance 1 (MxA), 2'5'-oligoadenylate synthetase (OAS), and cig5. The expression of these genes was further confirmed in JCV-infected PHFG cells and the human glioblastoma cell line U87MG to ensure the specificity of JCV in inducing this strong antiviral response. Results obtained by real-time RT-PCR and Western blot analyses supported the microarray data and provide temporal information related to virus-induced changes in the IFN response pathway. Our data indicate that the induction of an antiviral response may be one of the cellular factors regulating/controlling JCV replication in immunocompetent hosts and therefore constraining the development of PML.

Human immunodeficiency virus-associated peripheral neuropathies

Peripheral neuropathy has emerged as the most common neurologic complication of human immunodeficiency virus (HIV) infection. It will continue to play an Important role in HIV Infection given the fact that HIV-infected Individuals are living longer, are at risk of long-term metabolic complications, and face an Increasing exposure to potentially neurotoxic antiretroviral drugs. We review the various types of peripheral neuropathy that have been associated with HIV infection, including distal symmetrical polyneuropathy, toxic neuropathy from antiretroviral drugs, diffuse infiltrative lymphocytosis syndrome, inflammatory demyelinating polyneuropathies, multifocal mononeuropathies, and progressive polyradiculopathy.

The neuropsychological and neurological impact of hepatitis C virus co-infection in HIV-infected subjects

OBJECTIVE

To evaluate the effect of hepatitis C virus (HCV)/HIV co-infection on neuropsychological performance and neurological status in HIV/HCV treatment-naive HIV-1-infected individuals we conducted a cross-sectional study using baseline data from an HIV therapy trial.

METHODS

HCV status was determined by the presence of anti-HCV antibodies. Neuropsychological function was evaluated by Trailmaking tests, and the Digit Symbol Task. Depression was assessed using the Center for Epidemiologic Studies--Depression Scale. Sleep quality was evaluated by the Pittsburgh Sleep Quality Index and anxiety by the State-Trait Anxiety Inventory for Adults. A questionnaire was designed grading the severity of a variety of symptoms.

RESULTS

Of 264 patients with HCV status data, 30 were HCV positive and 234 were HCV negative. Both groups were comparable except that HCV-positive individuals had a higher prevalence of intravenous drug use and lower educational level. The HCV-positive group had a significantly lower neuropsychological performance overall. Multivariate modeling supported an association between HCV infection status with test performance in the Digit Symbol Task and mood parameters even when controlling for potentially confounding variables. Marginal differences were noted with respect to symptom questionnaire scores and global sleep. No differences were noted with respect to anxiety.

CONCLUSION

The findings suggest that HCV/HIV co-infection has an adverse impact on neuropsychological function. HCV may also be associated with depressed mood, particularly somatic depressive symptoms. Although confounding contributors to neuropsychological performance are difficult to exclude, exploratory modeling supports the association between HCV infection status and some impairment of neuropsychological performance and depressed mood.