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Biomedical subjects

R L Brey

Publications and source records attributed to R L Brey.

48 records · Page 3Linked to original sources

Cerebrospinal fluid anti-cardiolipin antibodies in patients with HIV-1 infection.

Both cerebrospinal fluid (CSF) immunologic abnormalities and serum anti-cardiolipin antibodies (aCL) have been reported in patients with HIV-1 infection. The antibody specificity of only a small amount of the total CSF IgG in these patients is known, and is directed against a variety of HIV-1 antigens. The specificity of the remaining CSF IgG is unknown. We report the results of the first study of CSF aCL in an HIV-1-infected population. We measured aCL IgG and IgM in the CSF of 21 HIV-1-infected patients without nervous system symptoms or AIDS, and in four HIV-1-negative controls. Twelve HIV-1-infected patients had an abnormal serum aCL value and CSF immunologic abnormalities and 9 HIV-1-infected patients had either abnormal serum aCL or CSF immunologic abnormalities but not both, or were normal in both regards. There was no difference between any HIV-1-infected patient and controls for CSF aCL IgM. Nine of 12 patients with an abnormal serum aCL and CSF immunologic abnormalities had CSF aCL IgG values that were at least 5 SD above normal control values, whereas none of the remaining patients had abnormal CSF aCL IgG values. All patients with abnormal CSF aCL IgG values had an intact blood-brain barrier as evidenced by an albumin index of less than 9, and all had nonreactive CSF VDRL tests. These data demonstrate that aCL IgG is produced intrathecally in some HIV-1-infected patients.

Adult↗

Antiphospholipid antibodies and cerebral ischemia in young people.

The importance of a prothrombotic state as a cause of ischemic stroke in young adults is ill defined. We examined 46 unselected patients under age 50 years with cerebral ischemia for anticardiolipin antibody (aCL) and lupus anticoagulants (LA), over a 3-year-period. Age- and sex-matched patients with other neurologic diseases served as a noncerebral ischemia comparison group to test whether (1) stroke/transient ischemic attacks (TIA) in young people is associated with aCL and/or LA, and (2) their presence is specific to cerebral ischemia. In the stroke/TIA group, 21 patients had aCL or LA and 25 had neither, whereas in the control group, 2 patients had aCL and 24 had neither. Equal numbers of stroke/TIA patients with and without antiphospholipid antibodies (aPL) had other stroke risk factors. Patients with aPL and cerebral ischemia, however, had a more frequent history of multiple events than those without them. These antibodies occur with undue frequency in young patients with stroke/TIA and are not associated with a concurrent diagnosis of systemic lupus in most cases. A coexistent aPL-associated prothrombotic state may be a key determinant of whether patients with atherosclerosis, mitral valve prolapse, or other structural lesions experience recurrent ischemia.

Adult↗

Neuropsychological and neurological function of human immunodeficiency virus seropositive asymptomatic individuals.

Although individuals with acquired immunodeficiency syndrome (AIDS) are often impaired on a variety of neuropsychological tasks, questions remain as to when neuropsychological decline can be reliably detected during the course of human immunodeficiency virus (HIV) infection. Detailed neuropsychological testing was accomplished on a cohort of 83 immunologically and neurologically intact asymptomatic HIV-infected individuals drawn from a larger pool of 649 US Air Force personnel with HIV antibodies. These asymptomatic subjects were compared with a group of HIV-negative subjects, and no significant differences in neuropsychological functioning were found. No significant neuropsychological differences were found as a function of cerebrospinal fluid abnormalities in these asymptomatic subjects. When data from 13 subjects with immune compromise were included in the analyses, those with abnormal cerebrospinal fluid values performed significantly poorer on a task of verbal memory, suggesting that cognitive dysfunction is antedated by immunological decline. Methodological problems that inhibit specification of the incidence, prevalence, and natural history of HIV-related cognitive impairment are discussed, as are data suggesting that previously published high estimates of the frequency of HIV-related dementia may not be representative of all HIV-infected populations.

Central Nervous System↗

Lack of cerebrospinal fluid myelin basic protein in HIV-infected asymptomatic individuals with intrathecal synthesis of IgG.

We evaluated 130 consecutive HIV-infected neurologically asymptomatic individuals for intrathecal IgG production and myelin basic protein (MBP) levels. Although 56.7% of immunologically normal and 68.8% of immunocompromised patients had some CSF abnormality, no patient had an abnormal MBP level. The lack of MBP elevation in the CSF of these patients suggests that the production of intrathecal IgG is not related to active demyelination.

Acquired Immunodeficiency Syndrome↗

Focal and/or lateralized polymorphic delta activity. Association with either 'normal' or 'nonfocal' computed tomographic scans.

Focal continuous polymorphic delta activity (PDA) is classically taught to be associated with destructive lesions of cerebral white matter. One hundred patients with focal or lateralized continuous PDA recorded by an electroencephalogram who also had computed tomographic (CT) scans of the head performed at approximately the same time were studied. Thirty-three percent had normal or "nonfocal" abnormalities on their CT scans. Most of these had a history of either seizures (51%) or transient cerebral ischemia/stroke (27%); however, a wide variety of causes were possible. This high percentage of patients with focal continuous PDA without corresponding CT scan lesions supports the concept that the electroencephalogram is a physiologic study that is complementary to anatomic imaging techniques.

Adolescent↗

Spectrum of cerebrospinal fluid findings in various stages of human immunodeficiency virus infection.

This report summarizes the results of neurologic and cerebrospinal fluid (CSF) study findings in over 400 of the 649 human immunodeficiency virus-infected US Air Force personnel, evaluated as of Dec 31, 1987. Eighty percent of these patients were entirely asymptomatic and immunologically normal, 13% had low T-helper lymphocyte counts and/or cutaneous anergy, and only 7% had opportunistic infection. Sixty-three percent of all patients had some CSF abnormality. Sixty percent of the asymptomatic group had at least one abnormal result, over 25% had three or four CSF abnormalities, and over 7% had five or six abnormal values. When patients with evidence of blood-brain barrier leak were excluded, significant differences were seen between disease groups with regard to CSF glucose, CSF IgG levels, and CSF IgG synthesis. No human immunodeficiency virus-related central nervous system abnormalities were found on neurologic examination in immunologically intact asymptomatic patients regardless of CSF findings. No clear-cut predictor of impending central nervous system complications has, as yet, been identified from the CSF parameters studied.

Acquired Immunodeficiency Syndrome↗

Cerebrospinal fluid abnormalities in patients without AIDS who are seropositive for the human immunodeficiency virus.

Lumbar punctures were done on 114 consecutive active duty patients referred for evaluation of positive tests for antibodies to the human immunodeficiency virus (HIV). Eighty-eight percent of these patients appeared to have early HIV infections, as evidenced by intact delayed hypersensitivity, T helper lymphocyte counts greater than 400/mm3, and lack of constitutional symptoms. Forty-four (38.6%) of the patients met our criteria for abnormal cerebrospinal fluid (CSF); another 13 (11.4%) had borderline elevations of nucleated cells or protein and could not be definitely classified as having normal or abnormal CSF. No significant differences existed between the patients with normal and abnormal CSF with regard to age; sex; race; serum FTA-Abs; clinical staging; absolute T helper lymphocyte counts; or cytomegalovirus, Toxoplasma, or Epstein-Barr virus serologies. Seventy-two percent of the patients with abnormal CSF had evidence of possible viral infection of the central nervous system (CNS), as evidenced by increased CSF IgG, increased IgG synthesis rates, or the presence of oligoclonal bands. We found that a significant percentage of asymptomatic patients with apparent early HIV infections have abnormal CSF that is possibly due to CNS involvement by HIV.

Central Nervous System Diseases↗

Neuromyelitis optica: two new cases and review of the literature.

The clinical features of two recent cases of neuromyelitis optica are reviewed, along with 43 cases from the literature. Severe bilateral visual impairment, thoracic myelitis, prodromal symptoms suggesting a viral syndrome, and moderate pleocytosis of the cerebrospinal fluid (CSF) were characteristic. Respiratory failure developed in 22% of the cases. Seventy percent of patients improved neurologically, 14% had a poor neurological outcome, and 16% died in the acute stages. Predictors of a poor outcome were older age, marked CSF pleocytosis, and severe myelitis. Forty-two percent of patients had a recurrence of demyelinating disease after initial recovery, suggesting a diagnosis of multiple sclerosis. Fifty-eight percent of patients had a self-limited monophasic illness, consistent with a post-infectious encephalomyelitis. No clear predictors of patients at risk for recurrence were identified. CSF oligoclonal bands were absent in three patients with information available.

Adult↗

Antiphospholipid antibodies and ischemic stroke.

Antibodies directed against phospholipids are highly associated with episodes of venous and arterial thrombosis, which are often recurrent. There seems to be a skewed frequency of cerebral thrombosis when the arterial circulation is affected. Clinical clues that should lead to evaluation for aPL include stroke in a young adult, recurrent thrombosis or miscarriage, and thrombocytopenia. Associated laboratory abnormalities include a biologically false-positive test for syphilis, abnormal antinuclear antibody titers, and a high erythrocyte sedimentation rate. If the activated partial thromboplastin time is prolonged on routine screening and does not correct with mixing studies, a lupus anticoagulant should be suspected. However, more sensitive and specific tests are usually necessary to detect aPL. Many in vitro and more recently in vivo systems strongly suggest that aPL may be directly implicated in the pathogenesis of thrombosis. Optimal management of patients with aPL-associated thrombosis is unknown. The use of aggressive therapeutic management schemes with such agents as warfarin or corticosteroids is sometimes required.

Antibodies, Antiphospholipid↗

Antiphospholipid antibodies and complement activation in patients with cerebral ischemia.

Antiphospholipid antibodies (aPL) have been linked to stroke and TIA. The mechanism for aPL-associated thrombosis is uncertain, but could be related to complement-mediated membrane damage. Indirect evidence for complement activation (low C4 levels) has been associated with aPL, with variable correlation with disease manifestations. We measured complement activation directly using an ELISA for SC5b-9 in 26 patients with stroke/TIA; 13 with and 13 without aPL. Patient plasma levels of SC5b-9 were measured along with standard positive and 5 normal control samples. Nine patients with, whereas only one without, aPL had an abnormal SC5b-9 level (p = 0.0018, Fisher's Exact Test). These data confirm a relationship between aPL and complement activation, which argues for an active autoimmune process in aPL-associated thrombosis and suggests that complement activation may play a pathogenic role.

Adult↗