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Biomedical subjects

L G Epstein

Publications and source records attributed to L G Epstein.

At least 91 records · Page 5Linked to original sources

Human immunodeficiency virus type 1 (HIV-1) infection of the nervous system: a review.

Human immunodeficiency virus type I (HIV-1) is associated with a spectrum of neurological disorders. At the time of primary HIV-1 infection, an acute aseptic meningitis or encephalitis indicates central nervous system invasion. Evidence of HIV-1 infection is found in the CSF of most asymptomatic seropositive individuals, suggesting viral persistence in the nervous system. After a long incubation period, viral activation is signaled by expression of HIV-1 antigen in the CSF, which correlates with a profound dementia in adults or with an analogous progressive encephalopathy in children. The neuropathological substrate of this dementing process consists of multinucleated giant cells and diffuse white matter pallor. Immunocytochemical and in situ hybridization studies demonstrate that antigen presenting cells, including blood derived macrophages and resident brain microglia, are directly infected by HIV-1, and participate in the formation of the syncytial giant cells. Astrocytes and endothelial cells may also be infected, but evidence for infection of oligodendroglia and neurons is lacking. Studies of lentiviral encephalitides in ungulates and non-human primates emphasize the importance of specific viral antigenic stimulation and the role of inflammatory cells as direct or indirect mediators of tissue damage. The disorders of the peripheral nervous system described in patients with HIV-1 infection have not been convincingly linked to direct viral infection. At least two of the neuromuscular complications, the inflammatory motor neuropathy and polymyositis are likely to have an autoimmune pathogenesis.

Acquired Immunodeficiency Syndrome↗

Congenital acquired immunodeficiency syndrome and congenital toxoplasmosis: pathologic support for a chronology of events.

We report a case of congenital acquired immunodeficiency syndrome (AIDS) with congenital opportunistic toxoplasmosis. The thymic histopathology was that seen in childhood AIDS cases and not that seen in primary congenital toxoplasmosis. The toxoplasma infection was selectively localized to the brain and the serum titers were paradoxically low as reported in most adult cases of AIDS with secondary infection by the parasite. These findings strongly suggest that the infection by the human immunodeficiency virus (HIV) preceded the toxoplasma infection in the fetus.

AIDS Serodiagnosis↗

Expression of human immunodeficiency virus in cerebrospinal fluid of children with progressive encephalopathy.

The retrovirus that causes acquired immune deficiency syndrome (AIDS) is now designated the human immunodeficiency virus (HIV). The cerebrospinal fluid (CSF) of 27 children with HIV infection was assayed for intra-blood-brain barrier (IBBB) synthesis of HIV-specific antibodies and for the presence of HIV antigen. In this cohort, 11 children had a progressive encephalopathy (PE), 9 had a static encephalopathy (SE), and 7 had normal neurological findings (N). IBBB synthesis of HIV-specific antibodies was identified (using matched serum and CSF specimens) in 7 of 11 children with PE, 4 of 9 children with SE, and 2 of 7 children with N. HIV antigen was found (using a highly sensitive solid-phase enzyme immunoassay) in the CSF of 8 of 11 children with PE, none of the children with SE, and none of the 7 children with N. On the basis of these data, we conclude that: IBBB synthesis of HIV antibodies indicates invasion of the central nervous system but may reflect prior or current infection; and HIV antigen in CSF indicates viral expression and correlates with the occurrence of PE. These findings strongly implicate HIV as the causative agent of PE in these children. The assay for HIV antigen in the CSF may be of value in determining the prognosis of children with HIV infection and for evaluating the efficacy of therapeutic agents against this retrovirus.

Acquired Immunodeficiency Syndrome↗

Pathogenesis of HIV and its implications for serodiagnosis and monitoring of antiviral therapy.

Human immunodeficiency virus (HIV) is lymphotropic and neurotropic. In vivo clinical and immunological abnormalities develop in a large proportion of long-term HIV antibody seropositive persons. Different stages of HIV infection are marked by expression of HIV genes, production of HIV antibodies, formation of antigen/antibody complexes and clearance of such complexes. Transient HIV antigenemia appearing generally 6-8 wk prior to HIV antibody (HIV-Ab) seroconversion and lasting 3-4 mth is generally seen in acute infection. IgM antibodies predominantly to core proteins may occasionally be detectable when, or just before, IgG antibodies appear. If IgG antibodies to both envelope and core proteins persist in the absence of HIV-Ag the short-term prognosis is relatively good. However, HIV-Ag seroconversion may appear at any time after HIV-Ab seroconversion. Progression to AIDS is strongly associated with declining or absent levels of IgG antibodies to p24. IgG2 and IgG4 antibodies to HIV, which are mainly directed to p24, disappear most dramatically. Titers of antibodies to HIV p24 below 64 are strongly associated with the presence of HIV antigen and a poor clinical outcome. HIV antigen was detected frequently in sera from children in all stages of infection in contrast to adults whose sera were generally HIV-Ag negative when asymptomatic and positive when AIDS was apparent. HIV antigen may be less efficiently detected with the present assays in sera from regions where the prototype strains of HIV (HTLV-III and LAV) are less prevalent, like Central Africa. Persistence of HIV-Ag in cerebrospinal fluid (CSF) appears to be pathognomonic for progressive encephalopathy, particularly in children. Levels of HIV-Ag in serum, and possibly in CSF, can be decreased by nucleoside analogues, such as AZT. This indicates HIV-Ag and possibly antibody to HIV core protein p24 as suitable markers for selecting individuals for antiviral therapy as well as monitoring the efficacy of such therapy.

Acquired Immunodeficiency Syndrome↗

Intra-blood-brain barrier synthesis of human immunodeficiency virus antigen and antibody in humans and chimpanzees.

The presence of human immunodeficiency virus (HIV) antigens in cerebrospinal fluid (CSF) was associated with progressive encephalopathy in adult and pediatric patients with acquired immunodeficiency syndrome (AIDS). HIV antigen was detected in CSF from 6 of 7 AIDS patients with progressive encephalopathy. By contrast, HIV antigen, whether free or complexed, was detected in CSF from only 1 of 18 HIV antibody seropositive patients without progressive encephalopathy and from 0 of 8 experimentally infected chimpanzees without clinical signs. Intra-blood-brain barrier synthesis of HIV-specific antibody was demonstrated in the majority of patients with AIDS (9/12) or at risk for AIDS (8/13) as well as in the experimentally infected chimpanzees, indicating HIV-specific B-cell reactivity in the brain without apparent neurological signs. In 6 of 11 patients with HIV infection, antibodies synthesized in the central nervous system were directed against HIV envelope proteins. Active viral expression appears to be necessary for both the immunodeficiency and progressive encephalopathy associated with HIV infection.

AIDS-Related Complex↗

Ultrastructural morphology and intracellular production of human immunodeficiency virus (HIV) in brain.

This is a comparative ultrastructural study of human immunodeficiency virus (HIV) particles in infected H9 lymphocyte cultures and in the brain of a six-year-old boy with acquired immunodeficiency syndrome (AIDS) encephalopathy. Viral particles in the cultures and the brain were of various sizes and shapes; particles ranged from 70 to over 160 nm in diameter, with a variable position of dense nucleoids and less dense core shells. In the brain, viral particles were located free in the cytoplasm of both multinucleated giant cells and mononuclear macrophage-like cells. There was intracellular budding of HIV particles from unidentified membranes, yielding intracellular immature or recently budded particles, with crescentic densities. By contrast, HIV particles in the infected H9 lymphocytes were not free in the cytoplasm but were instead located either extracellularly or in intracellular vacuoles. A small percentage of cells in the cultures were surrounded by immature particles only. Production (replication) of HIV occurred within infected macrophage-like cells in the brain of the child.

Acquired Immunodeficiency Syndrome↗

Relationship between HTLV-III neutralizing antibody and clinical status of pediatric acquired immunodeficiency syndrome (AIDS) and AIDS-related complex cases.

To investigate a possible protective role of HTLV-III neutralizing antibodies in individuals exposed to the virus, sera of children with acquired immunodeficiency syndrome or acquired immunodeficiency syndrome-related complex were analyzed for neutralizability of HTLV-IIIB infectivity. Twelve pediatric patients (nine acquired immunodeficiency syndrome, three acquired immunodeficiency syndrome-related complex) were clinically stable and had survived more than 2 yr postonset. Their predominant clinical problems included lymphocytic interstitial pneumonia, candidiasis, recurrent bacterial infections, failure to thrive, and lymphadenopathy. Twelve additional children (all acquired immunodeficiency syndrome) were classified as clinically poor; 10 of them had died. Their median length of survival was less than 2 yr, and their disease spectrum included progressive encephalopathy, thymic depletion or atrophy, and Pneumocystis carinii pneumonia in addition to many of the clinical features of the stable children. All (100%) of the stable patients possessed serum neutralizing antibody in contrast to only one of the 12 (8%) clinically poor patients. A simple decline in immunologic reactivity to HTLV-III antigens with disease progression did not account for this difference, since HTLV-III antibody titers of the clinically poor cases (1 X 10(2) to 1 X 10(7)) ranged as high as those of the stable cases (1 X 10(4) to 1 X 10(7)) when measured by the ELISA technique. Although stable cases possessed a higher geometric mean titer (2.8 X 10(5)) by ELISA than the poor cases (4 X 10(4)), this difference was not statistically significant. Serial serum samples from stable children exhibited continual neutralizing antibody activity while two of three clinically poor cases lacked neutralizing activity in serial specimens.(ABSTRACT TRUNCATED AT 250 WORDS)

AIDS-Related Complex↗

Detection of HTLV-III RNA in lungs of patients with AIDS and pulmonary involvement.

A majority of pediatric patients and rare adult patients with the acquired immunodeficiency syndrome (AIDS) develop a chronic respiratory disorder referred to as "lymphocytic interstitial pneumonitis" (LIP). Efforts to identify an infectious agent responsible for this process so far have failed. In this study, frozen sections of lungs from patients with AIDS and pulmonary disease were tested by in situ molecular hybridization for the presence of cells infected with human T-cell lymphotropic virus type III (HTLV-III) and expressing viral RNA. In the case of an infant with LIP, a relatively high frequency (0.1%) of cells in the lung were found to be positive for HTLV-III RNA. This number is the lower limit of total cells infected since the in situ hybridization technique as applied in this study depends on expression of HTLV-III genes, and previous evidence indicates that a proportion of cells infected with HTLV-III may not express viral RNA. Moreover, this degree of infection of the lung is likely limited to LIP, since in ten patients with AIDS and pulmonary diseases other than LIP, only 0% to 0.002% of cells in lung were positive for viral RNA expression. Thus, HTLV-III may play a direct causal role in the development of LIP in infected patients, implicating its involvement in yet another of the diverse clinical diseases associated with this virus.

Acquired Immunodeficiency Syndrome↗

Expression of human immunodeficiency virus antigen (HIV-Ag) in serum and cerebrospinal fluid during acute and chronic infection.

Human immunodeficiency virus antigen (HIV-Ag) was detected in the serum of most adult (13/16) and paediatric (6/6) AIDS patients and rarely in the serum of symptomless seropositive controls (1/13). It was present in the cerebrospinal fluid (CSF) of all 5 children and most (5/9) adults with AIDS-related encephalopathy, but not in the CSF of 13 symptomless seropositive controls, of whom 8 had antibody in the CSF. A longitudinal study of 1 of the controls with antibody in the CSF showed that HIV-Ag in CSF was present transiently before the occurrence of antibody in the CSF. In serial samples of serum from 35 men who seroconverted HIV-Ag was detected in 11 persons--in 5 before seroconversion and in 6 after. 3 of the 6 who became antigenaemic after seroconversion remained so for the rest of the follow-up. AIDS was diagnosed in 1 patient, 3 months after HIV-Ag was first detected in serum and 6 months after seroconversion. The findings suggest that HIV-Ag appears early and transiently in primary HIV infection. Antibody production follows, after which HIV-Ag may disappear. Its persistence or reappearance seems to correlate with clinical, immunological, and neurological deterioration.

Acquired Immunodeficiency Syndrome↗

Hypothesis: AIDS encephalopathy is due to primary and persistent infection of the brain with a human retrovirus of the lentivirus subfamily.

Recent evidence has demonstrated that human T-lymphotropic retroviruses are present in the brain of patients with acquired immunodeficiency syndrome (AIDS). Studies by neuropathological, ultrastructural and nucleic acid hybridization techniques indicate that these human retroviruses are neurotropic as well as lymphotropic. Striking similarities to the animal retroviruses of the lentivirus subfamily provide a rationale to implicate these human retroviruses (lentiviruses) in the pathogenesis of AIDS encephalopathy.

Acquired Immunodeficiency Syndrome↗

Pathologic features of AIDS encephalopathy in children: evidence for LAV/HTLV-III infection of brain.

The neuropathologic findings in 11 children with a new CNS disorder that occurs in children with the acquired immunodeficiency syndrome (AIDS) and is postulated to be due to LAV/HTLV-III, the virus that causes AIDS, are reported. The children, who ranged in age from 4 months to 11 years, died of AIDS complicated by progressive encephalopathy. Ten of the children either had positive serum antibody for LAV/HTLV-III or had received blood products from donors later found to be antibody-positive. Examination of the brains of these children at autopsy revealed a unique constellation of findings, including varying degrees of diminished brain weight in all cases, inflammatory cell infiltrates in nine brains, multinucleated cells in eight, three of which also contained multinucleated giant cells, vascular calcification in ten, vascular and perivascular inflammation in five, and white matter changes in nine. Inflammatory and vascular lesions were most prominent in basal ganglia and pons. LAV/HTLV-III retroviral particles, associated with multinucleated giant cells, were observed in two brains on electron microscopic examination. These two and one additional brain had evidence of the LAV/HTLV-III genome by hybridization studies. Only one brain had a recognizable opportunistic infection.

Acquired Immunodeficiency Syndrome↗

Neurologic manifestations of human immunodeficiency virus infection in children.

This report describes the neurologic manifestations of 36 children with human immunodeficiency virus (HIV) infection. In this cohort, in 16 of 21 children with acquired immunodeficiency syndrome (AIDS), three of 12 children with AIDS-related complex, and one of three asymptomatic seropositive children, a progressive encephalopathy developed. Neurologic signs were often detected early but tended to worsen coincident with progression of the immunodeficiency. The presence of progressive encephalopathy correlated with the absence of serum neutralizing antibodies to HIV and with a poor, usually fatal, outcome. The incubation period from initial HIV infection in the perinatal period to the onset of progressive encephalopathy varied from 2 months to 5 years. Intrablood-brain barrier synthesis of HIV-specific antibodies was demonstrated in eight of 14 children with AIDS and AIDS-related complex, indicating active brain infection with HIV. In three cases this was unassociated with progressive neurologic signs. Unique neuropathologic findings in children who died with HIV infection further suggest that the progressive encephalopathy is the result of primary and persistent infection of the brain with this retrovirus. These findings broaden the spectrum of HIV infection in children and have important implications for the development of antiviral therapy.

Acquired Immunodeficiency Syndrome↗

HTLV-III infection in brains of children and adults with AIDS encephalopathy.

Unexplained debilitating dementia or encephalopathy occurs frequently in adults and children with the acquired immune deficiency syndrome (AIDS). Brains from 15 individuals with AIDS and encephalopathy were examined by Southern analysis and in situ hybridization for the presence of human T-cell leukemia (lymphotropic) virus type III (HTLV-III), the virus believed to be the causative agent of AIDS. HTLV-III DNA was detected in the brains of five patients, and viral-specific RNA was detected in four of these. In view of these findings and the recent demonstration of morphologic and genetic relatedness between HTLV-III and visna virus, a lentivirus that causes a chronic degenerative neurologic disease in sheep, HTLV-III should be evaluated further as a possible cause of AIDS encephalopathy.

Acquired Immunodeficiency Syndrome↗

Progressive encephalopathy in children with acquired immune deficiency syndrome.

We are reporting the cases of four children with a diagnosis of acquired immune deficiency syndrome (AIDS) who demonstrated a progressive encephalopathy manifested by loss of motor milestones or intellectual abilities, and weakness with pyramidal tract signs. Two patients were ataxic. One child was cortically blind and suffered myoclonic jerks before his death. Two of the patients had isolated seizures at some time during the disease course. Two patients developed secondary microcephaly and all four patients showed cortical atrophy on computed tomographic scanning. Three of the patients died. Postmortem neuropathological findings included gross cortical atrophy, microglial nodules, and intranuclear inclusions, as are described in the subacute encephalitis reported in adult AIDS patients. We propose that the possible pathogenetic mechanisms of this encephalopathy include opportunistic or persistent viral infection of the brain.

Acquired Immunodeficiency Syndrome↗