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Query: UMLS:C0021051 (immunodeficiency)
 71,517 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Progressive cognitive impairment in human immunodeficiency virus (HIV) infection, called acquired immunodeficiency syndrome (AIDS) dementia complex (ADC), significantly influences the social prognosis of afflicted patients. The frequency and character in different stages of the infection are controversially discussed. In previous studies, differences in the selection of patients and methods of testing led to widely differing results. For these reasons, in the present prospective study on 45 HIV-infected patients, a structured psychiatric interview (SIDAM) was conducted based on the algorithm of diagnosing dementia in DSM-III-R and the ICD-10 guidelines. The psychopathological findings are expressed in syndrome scores; the results are summarized in a total score (SISCO). The interview contains the Mini-Mental State Examination. The degree of psychosocial functioning was estimated on the global assessment of functioning, Axis V of DSM-III-R. In stages preceding AIDS, only slight cognitive dysfunction was found compared with age- and education-matched normal controls, and this caused no relevant disturbance of psychosocial functioning. In 9 patients with manifest AIDS, dementia was diagnosed with DSM-III-R criteria and ICD-10 guidelines (30% of the AIDS patients). They showed marked impairment of intellectual ability, memory, verbal ability and calculation and constructional ability and fewer cortical focal symptoms (aphasia and apraxia). Corresponding to previous studies, major cognitive dysfunction in HIV infection can be characterized as subcortical dementia.
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PMID:Cognitive impairment, dementia and psychosocial functioning in human immunodeficiency virus infection. A prospective study based on DSM-III-R and ICD-10. 842 19

There is controversy over whether cognitive impairment occurs in early human immunodeficiency virus (HIV) disease. When impairment is reported, findings are typically subclinical, affect only a minority, and their relationship to occupational functioning has not been established. Despite such findings, it has been recommended that HIV-seropositive pilots be disqualified from flying. This paper reviews research relevant to measuring performance decrements in HIV-infected aviators. Based upon current data, we conclude that although subtle neurobehavioral dysfunction may occur in some asymptomatic HIV-seropositive individuals, there is no research which has demonstrated associated decrements in aviation-related skills. Thus, it may be premature to recommend medical disqualification of all HIV-seropositive aviators. We propose, instead, that sensitive neurocognitive measures, incorporated into a comprehensive neurodiagnostic evaluation, could be used to evaluate asymptomatic HIV-seropositive aviators. Only those who are impaired on evaluation would be disqualified from flying. Concurrently, research investigating the relationship between abnormalities and aviation abilities would be conducted.
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PMID:Measuring performance decrements in aviation personnel infected with the human immunodeficiency virus. 843 Nov 91

HIV encephalopathy, which is probably primarily caused by human immunodeficiency virus, is the most common neurological disorder in HIV-infected patients and is more frequent than opportunistic diseases of the central nervous system. It is characterized most often by slowly progressing cognitive impairment, psychomotoric slowing and increasing apathy. The syndrome is found almost exclusively in the late stages of HIV infection; its frequency in patients with full-blown AIDS is estimated as being between 40 and 70%. Although numerous studies have demonstrated alterations in the electrophysiological parameters, cerebral perfusion and cerebrospinal fluid in many asymptomatic patients, there are no reliable parameters that can predict the risk of developing HIV encephalopathy. Also, there is no sufficient correlation between the extent of the frequent but mostly subtle neuropathological changes and the clinical degree of the severity of the encephalopathy. The mechanisms causing cerebral injury are poorly understood. Recent studies indicate that the indirect effects of HIV infection of the brain are the most important pathogenetic factors. In particular, certain viral proteins and cytokines produced by infected macrophages or activated microglia seem to induce neuronal dysfunction and finally loss of nerve cells.
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PMID:[HIV encephalopathy--clinical aspects, neuropathology and pathogenesis]. 845 Aug 99

We used magnetic resonance imaging (MRI) and water-suppressed proton magnetic resonance spectroscopic imaging to study the effects of human immunodeficiency virus (HIV) infection on the brains of 10 individuals with cognitive impairment due to HIV and seven normal controls. 1H spectra from nine 2.5-ml volumes in the centrum semiovale and the mesial cortex showed significantly reduced N-acetylaspartate (NAA) relative to choline and creatine in the cognitively impaired HIV-infected subjects. This reduction was due to a nonlocalized decrease of NAA in these patients, only two of whom had moderate atrophy and white matter signal hyperintensities on MRI. Since NAA is a putative neuronal marker, the findings suggest neuronal damage in early stages of HIV infection that is not evident on standard MRI and are consistent with the neuropathologically known neuronal loss.
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PMID:Reduced brain N-acetylaspartate suggests neuronal loss in cognitively impaired human immunodeficiency virus-seropositive individuals: in vivo 1H magnetic resonance spectroscopic imaging. 845 Sep 92

The pattern of expression of GFAP immunoreactivity in astrocytes of the juvenile rhesus monkey cortex was examined following infection with simian immunodeficiency virus (SIV). Blocks of cerebral cortex plus subjacent white matter from saline- and formalin-perfused brain were examined by peroxidase-linked immunochemical and immunofluorescence staining of deparaffinized sections. Strong GFAP immunoreactivity was found in astrocytic cells in both uninfected and SIV-infected juvenile macaque in the subpial cerebral cortex and in subcortical white matter, where GFAP-positive cells were abundant. GFAP staining of cortical layers 2-6 on the other hand was weak or absent in three uninfected controls and one infected animal without cognitive impairment, but moderate to strong in animals productively infected with SIV that demonstrated cognitive and/or motor impairment. These data demonstrate a cortical locus of astrocytic activation in rhesus monkeys infected with primate immunodeficiency virus isolate SIVB670 which, like HIV-1 in man, causes motor/cognitive impairment as well as immunodeficiency disease.
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PMID:Cortical astrocytosis in juvenile rhesus monkeys infected with simian immunodeficiency virus. 847 48

The CNS is frequently involved in human immunodeficiency virus (HIV) infection. In recent studies using proton magnetic resonance spectroscopy, investigators found a significant reduction in N-acetyl aspartate, a metabolic marker of neurons, in late stages of dementia. To further understand the relationship between proton magnetic resonance spectroscopy changes and clinical disease and dementia, we compared 20 HIV-infected patients presenting at varying stages of acquired immunodeficiency syndrome (AIDS) dementia complex and infection to 10 age-matched controls. We found a significant reduction in N-acetyl aspartate/creatine only in patients who had advanced dementia and CD4 counts less that 200/microliter. By contrast, a significant elevation in compounds containing choline was present in patients in the early stages of HIV infection of who had CD4 counts greater than 200/microliter, in patients with normal MRI scans, and in all AIDS dementia complex groups, including subjects with no or minimal cognitive impairment. An elevated choline level also occurred in later stages of HIV infection (CD4 < 200/microliter). Our results suggest that an increase in choline occurs before N-acetyl aspartate decrements, MRI abnormalities, and the onset of dementia, and may therefore provide a useful marker for early detection of brain injury associated with HIV infection.
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PMID:Brain choline-containing compounds are elevated in HIV-positive patients before the onset of AIDS dementia complex: A proton magnetic resonance spectroscopic study. 861 83

An estimated 7-28% of patients infected by the human immunodeficiency virus (HIV) develop dementia and at least 50% develop mild neurocognitive impairment. Past studies have shown odor identification impairments in HIV + neurocognitively impaired patients. It is difficult, however, based on an odor identification test to state with certainty that individuals with cognitive impairment have sensory olfactory deficits, because odor identification tests are known to draw upon cognitive skills. In the present study odor detection sensitivity was evaluated using an ascending, forced-choice, two-alternative, odor threshold test for butanol. Subjects were divided into three groups, HIV seropositive (HIV+) neurocognitively impaired, HIV+ neurocognitively unimpaired, and HIV negative, based on neurological and psychological testing. An analysis of variance revealed significantly poorer odor sensitivity for the HIV+ neurocognitively impaired group than for the two control groups. A significant negative correlation between degree of cognitive impairment and olfactory sensitivity was also found. We suspect that the olfactory deficits found in the HIV+ neurocognitively impaired subjects are primarily due to damage to the central nervous system; however, nasal infection may be a contributing etiology.
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PMID:Odor sensitivity is impaired in HIV-positive cognitively impaired patients. 877 81

Previous studies in patients receiving interferon-alpha (IFN-alpha) therapy and patients with systemic lupus erythematosus have demonstrated that elevated cerebrospinal fluid (CSF) levels of IFN-alpha are associated with cognitive dysfunction. We measured IFN-alpha levels in CSF and blood by ELISA in human immunodeficiency virus (HIV)-positive patients with (n = 21) and without (n = 23) dementia and HIV-negative controls (n = 48). IFN-alpha was significantly elevated in the CSF of HIV-positive patients with dementia compared to those without dementia and controls. An increasing amount of IFN-alpha in the CSF was correlated with the clinical parameter of increasing Memorial Sloan Kettering scores; although these correlations were not statistically significant, they further suggest an association of increased CSF IFN-alpha with neurocognitive dysfunction in AIDS. Immunocytochemical staining of brains demonstrated IFN-alpha-positive macrophages and astrocytes in frontal cortex and white matter and IFN-alpha mRNA was detected by reverse transcriptase-polymerase chain reaction, further indicating that IFN-alpha is made by cells within the brain and suggesting that the significant increases of IFN-alpha protein found in the CSF of patients with HIV-associated dementia complex are derived from intrinsic brain cells such as macrophages and astrocytes. Increased local production of IFN-alpha during HIV infection may contribute directly or indirectly to the pathogenesis of HIV-associated dementia.
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PMID:A potential role for interferon-alpha in the pathogenesis of HIV-associated dementia. 890 53

Indirect mechanisms are implicated in the pathogenesis of the dementia associated with human immunodeficiency virus-type 1 (HIV-1) infection. Proinflammatory molecules such as tumor necrosis factor alpha and eicosanoids are elevated in the central nervous system of patients with HIV-1-related dementia. Nitric oxide (NO) is a potential mediator of neuronal injury, because cytokines may activate the immunologic (type II) isoform of NO synthase (iNOS). The levels of iNOS in severe HIV-1-associated dementia coincided with increased expression of the HIV-1 coat protein gp41. Furthermore, gp41 induced iNOS in primary cultures of mixed rat neuronal and glial cells and killed neurons through a NO-dependent mechanism. Thus, gp41-induced NO formation may contribute to the severe cognitive dysfunction associated with HIV-1 infection.
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PMID:Immunologic NO synthase: elevation in severe AIDS dementia and induction by HIV-1 gp41. 894 6

The spreading of human immunodeficiency virus (HIV) infection and its increasing scientific knowledge keep the medical staff involved with these patients in permanent need of updating themselves. The different neurologic manifestations caused by HIV are related to a variety of pathogenic mechanisms, as follows: immunodeficiency, autoimmunity, direct effects of the virus on the nervous system, and toxic and metabolic effects. The opportunistic infections are caused by the immunodeficiency due to the action of the virus on CD4+ T cells and on cells of the monocytic-macrophage lineage. Demyelinating polyradiculoneuropathy and polymyositis-like syndromes are related to autoimmune mechanisms involving, probably, the non-specific stimulation of T cells by viral proteins. The primary action of the virus on the nervous system brings out aseptic meningitis, cognitive dysfunction, dementia, vacuolar myelopathy and sensory polyneuropathy probably through liberation of neurotoxic products by the infected macrophages. Antiretroviral drugs and others used to treat patients with AIDS may also have neurotoxic effects. The better understanding of the neuropathogenesis of HIV infection will permit the use of new, and more specific, therapeutical options in the future as well as a more precocious control of its neurologic complications.
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PMID:[Neuropathogenesis of HIV infection]. 898 98


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