Isolation of HTLV-III from cerebrospinal fluid and neural tissues of patients with neurologic syndromes related to the acquired immunodeficiency syndrome

Management of infectious and immunological complications of acquired immunodeficiency syndrome (AIDS). Current and future prospects

AIDS is caused by a newly recognised virus (human immunodeficiency virus; HIV) which induces a profound defect in cellular immune function associated with increased susceptibility to opportunistic infections and certain malignancies. The clinical presentation of HIV ranges from asymptomatic infection to severe immunodeficiency manifesting as severe life-threatening infectious diseases or malignancies. While major research efforts are being directed toward development of vaccine and discovery of effective antiretroviral drugs, clinicians are faced with AIDS patients with multiple and complicated medical problems including opportunistic infections and certain malignancies. Currently, efforts are directed toward early diagnosis, treatment, and prevention of recurrence of these opportunistic infections. The current approaches are reviewed in this article. Major recent developments in AIDS research include the isolation of the HIV on culture and the availability of the antibody test. Aside from vaccine and antiretroviral drugs, other measures that may be of benefit in the treatment of AIDS patients are immunological enhancement and reconstitution. Several studies are underway to evaluate antiviral agents in the treatment of HIV infection. Those undergoing clinical trial include suramin, ribavirin, antimoniotungstate, phosphonoformate and azidothymidine. Immune enhancers that have been used include alpha- and gamma-interferon and interleukin-2. HLA-matched lymphocyte transfusions and bone marrow transplantations have been used alone and in combination to replace the AIDS patient's defective immune system.

Neuropathology of acquired immune deficiency syndrome (AIDS) in 53 autopsy cases with particular emphasis on microglial nodules and multinucleated giant cells

Brains from 53 autopsied acquired immune deficiency syndrome (AIDS) cases were examined with special attention to microglial nodules and multinucleated giant cells, which are two histological features of AIDS encephalopathy. Twenty-four (45%) of the 53 brains had microglial nodules in varying frequency. Four of these had microglial nodules alone and the rest had other pathological changes, such as opportunistic infections, CNS lymphomas, cerebrovascular lesions, and multinucleated giant cells. Eleven (46%) of the 24 brains with microglial nodules were accompanied by cytomegalovirus infection in the brain (one case) or body (five cases), or both (five cases). However, the remaining 54% of the brains had no morphological evidence of cytomegalovirus infection either in the brain or body. Five brains had multinucleated giant cells and microglial nodules. Two of these brains had numerous multinucleated giant cells, especially in the cerebral white matter, where, in one case, a spectrum of forms included mononuclear macrophages, intermediate forms of binuclear and trinuclear cells, and multinucleated giant cells. Images suggesting cell fusion were also observed. Electron microscopic examination of this area revealed many viral particles (80-130 nm in diameter) with rod-like cores, reminiscent of HTLV-III, in the cytoplasm of one cell.

HTLV-III-like particles within a cell process surrounded by a myelin sheath in an AIDS brain

HTLV-III-like particles were observed within a cell process surrounded by a myelin sheath, in the brain of a 4-year-old boy with AIDS encephalopathy. Similar particles were also observed in the mononuclear macrophage-like cells.

Inflammatory demyelinating peripheral neuropathies associated with human T-cell lymphotropic virus type III infection

Nine patients with inflammatory demyelinating polyneuropathies (IDP) were found to have human T-cell lymphotropic virus type III (HTLV-III) infection. The 8 men, 6 of whom were homosexual, and 1 woman, a former intravenous drug user, presented with progressive weakness. Two had lymphadenopathy but all were otherwise asymptomatic. Six had chronic IDP and 3 had Guillain-Barré syndrome. In addition to an elevated cerebrospinal fluid (CSF) protein level (mean, 193 mg/dl), most patients had cerebrospinal fluid pleocytosis (mean, 23 cells/mm3), a distinctive feature. All had reduced T4:T8 T-cell ratios. Results of nerve conduction studies were characteristic of demyelination. Nerve biopsies revealed intense inflammatory cell infiltrates and macrophage-mediated demyelination. The patients recovered either spontaneously or following treatment with corticosteroids or plasmapheresis. During a mean interval of 20 months after presentation, only 1 patient had developed acquired immune deficiency syndrome. Patients with HTLV-III infection have disordered immune function, and the mechanism of the development of the IDP is likely to be immunopathogenic. As a result of our experience, we suggest that all patients with IDP be tested for evidence of HTLV-III infection. We also found, although in uncontrolled trials, that treatment with either prednisone or plasmapheresis was followed by clinical improvement; since plasmapheresis is not likely to further depress cell-mediated immunity, we suggest that it be the initial therapy.

A human T-cell line resistant to cytopathic effects of the human immunodeficiency virus (HIV)

Infection of human helper T lymphocytes with the human immunodeficiency virus (HIV) results in a rapid induction of cytopathic effects and cell lysis. We isolated a variant of the human T-lymphoblastoid cell line, CEM, that is fully susceptible to HIV infection but resistant to virally induced cytopathic effects. Exposure of the cells, designated CR-10, to HIV resulted in the expression of viral antigens in 100% of cells within 6-9 days. Virus-infected cells remained fully viable and could be cultivated under standard culture conditions for a desired period of time. Parental CEM cells died within 9-12 days after HIV infection. Proviral DNA could be detected in the HIV-infected CR-10 cells by Southern blot and molecular hybridization 4-5 days after infection; the relative amount of proviral DNA reached maximum at Days 6-10 and remained stable during an 8-month follow-up period. Virus production by HIV-infected CR-10 cells was documented by electron microscopy and detection of reverse transcriptase activity in cell culture supernatants. HIV-infected CR-10 cells exhibited a down modulation of the OKT-3, OKT-4, OKT-4A, OKT-8, and OKT-11 T-cell surface markers, but not of the OKT-9 (transferrin receptor). One of the HIV persistently infected CR-10 cell clones has been kept in continuous culture for over 8 months. During this period, the cells remained fully viable, 100% positive for HIV antigens, and negative for most of the T-cell surface markers tested and continued to produce biologically active HIV. The CR-10 and HIV-infected CR-10 cell lines will be useful in studies on the biology of HIV and in the isolation and large-scale propagation of this virus.

CD8+ lymphocytes can control HIV infection in vitro by suppressing virus replication

Lymphocytes bearing the CD8 marker were shown to suppress replication of human immunodeficiency virus (HIV) in peripheral blood mononuclear cells. The effect was dose-dependent and most apparent with autologous lymphocytes; it did not appear to be mediated by a cytotoxic response. This suppression of HIV replication could be demonstrated by the addition of CD8+ cells at the initiation of virus production as well as after several weeks of virus replication by cultured cells. The observations suggest a potential approach to therapy in which autologous CD8 lymphocytes could be administered to individuals to inhibit HIV replication and perhaps progression of disease.

Persistent HIV antigenaemia and decline of HIV core antibodies associated with transition to AIDS

Sequential serum samples from 13 homosexual men who seroconverted for antibodies to human immunodeficiency virus (HIV) were tested for HIV antigen. In one of these men, who developed the acquired immune deficiency syndrome (AIDS), HIV antigenaemia preceded the onset of AIDS by more than a year and persisted throughout the course of the disease. This antigenaemia was accompanied by the disappearance of IgG antibody reactivity to the major HIV core protein p24. In none of the 12 others, who all remained without serious disease, were serum concentrations of HIV antigen detected, except on one occasion in one man. All their serum samples showed strong IgG antibody reactivity to p24. Nine children who were infected with HIV in 1981 by plasma transfusion from a single donor were also followed up for HIV antigenaemia. HIV antigen was almost constantly present in the serum (26 of 28 samples) of five children who developed AIDS related complex or AIDS and less often in the serum (four of 10 samples) of four children who remained free of symptoms. The two children who developed AIDS showed a virtual absence of antibody reactivity to p24. These results indicate that increased HIV gene expression is a contributing factor to the development of AIDS and also provide evidence for a switch from latent to active HIV infection.

Isolation of the human T-cell leukemia/lymphotropic virus type III from aqueous humor in two patients with perivasculitis of the retinal vessels

The human T-cell leukemia/lymphotropic virus type III (HTLV-III) has been isolated from aqueous humor in two patients with perivasculitis of the peripheral retinal vessels, an AIDS-related ocular manifestation. Both patients had antibodies to HTLV-III and although they presented with herpes zoster ophthalmicus, they did not present other symptoms known to be associated with HTLV-III infection. The isolation of HTLV-III from aqueous humor in these two patients with retinal perivasculitis suggests that the virus itself may play a role in the etiology of this ocular sign. The presence of infectious HTLV-III in the anterior chamber further emphasises the necessity to discard corneas from HTLV-III infected donors.

Stimulatory and inhibitory influences of human immunodeficiency virus on normal B lymphocytes

B-lymphocyte dysfunction is a characteristic feature of the acquired immunodeficiency syndrome (AIDS) and of the AIDS-related complex. The aim of the present study was to further examine the influences exercised by the human immunodeficiency virus (HIV; formerly called human T-lymphotropic virus type III or lymphadenopathy-associated virus, HTLV-III/LAV) on normal human B lymphocytes. An unfractionated protein preparation, made from HIV purified by density gradient centrifugation, was previously shown to induce differentiation of normal human B lymphocytes into immunoglobulin-secreting cells. In the present analyses, this B-lymphocyte response peaked on day 6 or 7 after culture initiation and was found to be independent of the requirement for monocytes but to require T cells. Responses could also be elicited in cultures of purified B cells by the addition of T cells that had been exposed to HIV antigen. Inhibitors of protein synthesis (puromycin and cycloheximide) abrogated the responses. In contrast to its stimulatory effects, the same virus preparation was previously shown to inhibit polyclonal responses that are normally elicited in peripheral blood lymphocyte cultures by a T-dependent stimulus (pokeweed mitogen) and T-independent stimulus (Epstein-Barr virus). The present studies suggest that the inhibitory effects of the HIV antigen studied herein are targeted primarily at the B lymphocytes. The role of T lymphocytes in the HIV antigen-mediated inhibitory effects, although demonstrated, could not be conclusively established as an essential pathway. These findings elucidate mechanisms by which components of HIV exert stimulatory as well as inhibitory effects on human B lymphocytes and thereby lead to the dysfunction of these cells in HIV infection.

Neurological complications and concomitants of AIDS

A survey of the literature of neurological manifestations associated with the acquired immune deficiency syndrome (AIDS) shows a broad disease spectrum affecting approximately one third of the patients in large hospital series. The complications include focal cerebral lesions caused by abscesses, lymphomas, leucoencephalopathy or infarcts as well as encephalitis, meningitis and myelitis. Most opportunistic infections of the central nervous system presumably are caused by toxoplasma gondii, cytomegalovirus and cryptococcus neoformans. One tenth of all patients have neurological disease as their initial symptom of AIDS. The diagnosis should always be considered in patients at risk and in males with an unusual neurological history or with a peculiar CT scan of the brain. Besides the opportunistic complications of AIDS, LAV/HTLV-III itself probably attacks the nervous system and gives rise to concomitant lesions of the long tracts of the spinal cord with ataxia, paresis and spasticity and to subacute encephalopathy and peripheral nerve abnormalities as well.

The T4 gene encodes the AIDS virus receptor and is expressed in the immune system and the brain

The isolation of clones encoding the human surface protein T4, and the expression of the T4 gene in new cellular environments, have enabled us to examine the role of this protein in the pathogenesis of AIDS. Our studies support a mechanism of AIDS virus infection that initially involves the specific interaction of the AIDS virus with T4 molecules on the cell surface. This association can be demonstrated on T4+ transformed T and B lymphocytes as well as epithelial cells. Furthermore, the presence of T4 on the surface of all human cells examined is sufficient to render these cells susceptible to AIDS virus infection. Our data suggest that the T4-AIDS virus complex is then internalized by receptor-mediated endocytosis. Finally, we find that the T4 gene is expressed in the brain as well as in lymphoid cells, providing an explanation for the dual neurotropic and lymphotropic character of the AIDS virus. In this manner, a T lymphocyte surface protein important in mediating effector cell-target cell interactions has been exploited by a human retrovirus to specifically target the AIDS virus to populations of T4+ cells.

Effects of mutations within the 3' orf open reading frame region of human T-cell lymphotropic virus type III (HTLV-III/LAV) on replication and cytopathogenicity

Mutations that eliminated the ability of the human T-cell lymphotropic virus type III to produce the 27-kilodalton 3' orf product did not eliminate the ability of the virus to replicate in and kill T4+ cells. A mutant carrying a mutation that deleted carboxy-terminal sequences from the envelope gene as well as the 3' orf sequences retained the ability to kill T4+ lymphocytes, but had a retarded replication rate.

The acquired immune deficiency syndrome: ocular findings and infection control guidelines

The acquired immune deficiency syndrome (AIDS) is characterised by a loss of normal cellular immunity in affected individuals which predisposes them to severe opportunistic infections and neoplasms. These pathological processes may affect the eye, and ocular involvement with an opportunistic infection or malignancy may be the first clue to the presence of AIDS. This article reviews the ocular manifestations of AIDS and concludes with infection control guidelines for ophthalmologists treating patients with AIDS and related conditions.

In vitro modification of human immunodeficiency virus infection by granulocyte-macrophage colony-stimulating factor and gamma interferon

The ability of recombinant human granulocyte-macrophage colony-stimulating factor (GM-CSF) and gamma interferon (IFN-gamma) to modify human immunodeficiency virus (HIV; also called HTLV-III/LAV) infection in the monocytic cell line U-937 was examined. When added to persistently infected cell cultures, GM-CSF at 30-300 units per ml produced maximal reductions in reverse transcriptase activity of 37-55% 10-14 days after its addition, whereas IFN-gamma produced reductions of 64-68% 10-17 days after addition. When used prior to acute HIV infection and maintained in the cell culture system, these cytokines reduced reverse transcriptase activity 90-100% and nearly eliminated viral antigen expression but did not prevent return of productive infection after their removal. These results indicate that, in a monocyte model of HIV infection, GM-CSF and IFN-gamma substantially restrict HIV expression and that these cytokines deserve further evaluation as therapeutic alternatives in HIV-related disorders.

Isolation and sequence of L3T4 complementary DNA clones: expression in T cells and brain

T lymphocytes express on their surface not only a specific receptor for antigen and major histocompatibility complex proteins, but also a number of additional glycoproteins that are thought to play accessory roles in the processes of recognition and signal transduction. L3T4 is one such T-cell surface protein that is expressed on most mouse thymocytes and on mature mouse T cells that recognize class II (Ia) major histocompatibility complex proteins. Such cells are predominantly of the helper/inducer phenotype. In this study, complementary DNA clones encoding L3T4 were isolated and sequenced. The predicted protein sequence shows that L3T4 is a member of the immunoglobulin gene superfamily. It is encoded by a single gene that does not require rearrangement prior to expression. Although the protein has not previously been demonstrated on nonhematopoietic cells, two messenger RNA species specific for L3T4 are found in brain. The minor species comigrates with the L3T4 transcript in T cells, whereas the major species is 1 kilobase smaller.

Neuroleukin: a lymphokine product of lectin-stimulated T cells

Neuroleukin is a lymphokine product of lectin-stimulated T cells that induces immunoglobulin secretion by cultured human peripheral blood mononuclear cells. Neuroleukin acts early in the in vitro response that leads to formation of antibody-secreting cells, but continued production of immunoglobulin by differentiated antibody-secreting cells is neuroleukin-independent. Although the factor is not directly mitogenic, cellular proliferation is a late component of the response to neuroleukin. Neuroleukin does not have B-cell growth factor (BCGF) or B-cell differentiation factor (BCDF) activity in defined assays. Neuroleukin-evoked induction of immunoglobulin secretion is both monocyte- and T-cell-dependent.

Molecular cloning and physical characterization of integrated equine infectious anemia virus: molecular and immunologic evidence of its close relationship to ovine and caprine lentiviruses

Molecular clones of the integrated form of the genome of equine infectious anemia virus (EIAV), the etiologic agent of a naturally occurring, worldwide disease of horses, were obtained. The restriction map of a full-length genome was determined. Additional evidence for the close evolutionary relationship between EIAV and a prototype lentivirus (caprine arthritis encephalitis virus) was acquired by Southern blotting and immunological analyses. An interspecies radioimmunoassay was developed in which EIAV and ovine and caprine lentiviruses could be detected equally well. These studies make available precisely defined reagents to pursue the study of the mechanisms of pathogenesis of lentiviral induced diseases.

Detection of AIDS virus in macrophages in brain tissue from AIDS patients with encephalopathy

One of the common neurological complications in patients with the acquired immune deficiency syndrome (AIDS) is a subacute encephalopathy with progressive dementia. By using the techniques of cocultivation for virus isolation, in situ hybridization, immunocytochemistry, and transmission electron microscopy, the identity of an important cell type that supports replication of the AIDS retrovirus in brain tissue was determined in two affected individuals. These cells were mononucleated and multinucleated macrophages that actively synthesized viral RNA and produced progeny virions in the brains of the patients. Infected brain macrophages may serve as a reservoir for virus and as a vehicle for viral dissemination in the infected host.

Cerebral granulomatous angiitis associated with isolation of human T-lymphotropic virus type III from the central nervous system

A 42-year-old homosexual man without evidence of immune deficiency developed cerebral granulomatous angiitis in association with the isolation of human T-lymphotropic virus type III (HTLV-III) from brain tissue and cerebrospinal fluid. This syndrome may be an additional neurological sequela of HTLV-III infection.

Cellular localization of human immunodeficiency virus infection within the brains of acquired immune deficiency syndrome patients

Dysfunction of the central nervous system (CNS) is a prominent feature of the acquired immune deficiency syndrome (AIDS). Many of these patients have a subacute encephalitis consistent with a viral infection of the CNS. We studied the brains of 12 AIDS patients using in situ hybridization to identify human immunodeficiency virus [HIV, referred to by others as human T-cell lymphotropic virus type III (HTLV-III), lymphadenopathy-associated virus (LAV), AIDS-associated retrovirus (ARV)] nucleic acid sequences and immunocytochemistry to identify viral and cellular proteins. Nine patients had significant HIV infection in the CNS. In all examined brains, the white matter was more severely involved than the grey matter. In most cases the infection was restricted to capillary endothelial cells, mononuclear inflammatory cells, and giant cells. In a single case with severe CNS involvement, a low-level infection was seen in some astrocytes and neurons. These results suggest that CNS dysfunction is due to indirect effects rather than neuronal or glial infection.

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.

Immunohistochemical identification of HTLV-III antigen in brains of patients with AIDS

Human T-cell lymphotropic virus type III (HTLV-III) has been isolated from neural tissues and cerebrospinal fluid (CSF) of patients with neurological syndromes associated with the acquired immune deficiency syndrome (AIDS) and the virus may be directly involved in the pathogenesis of the syndromes. To detect HTLV-III antigen in neural tissues from patients with AIDS, immunoperoxidase studies using a goat anti-HTLV-III serum were performed on frozen tissue sections of brain, spinal cord, and nerve from 13 patients with AIDS or HTLV-III-related neurological syndromes. HTLV-III was cultured from neural tissues or CSF in 11 of 13 of these patients. HTLV-III antigen was detected in the brains of 5 patients with AIDS and in none of the 13 non-AIDS control subjects. Rare positively stained cells were seen, frequently associated with capillaries and often located near microglial nodules. Morphologically, the cells resembled monocyte/macrophages and were found most frequently in the cortex of the frontal, temporal, and parietal lobes. These results provide further evidence that the subacute encephalitis of AIDS is associated with central nervous system infection by HTLV-III and that monocyte/macrophages are among the infected cell populations.

Search for HTLV-I and LAV/HTLV-III antibodies in serum and CSF of multiple sclerosis patients

In order to confirm the findings on the presence of antibodies against human T-lymphotropic retroviruses in subjects affected by multiple sclerosis we studied paired serum and CSF samples from 32 MS patients. Both ELISA and Western blot procedures were employed to detect antibodies against HTLV-I and LAV/HTLV-III antigens. Negative results were obtained in all samples examined, except one which was reactive to HTLV-I in ELISA but not in Western blot.

Management of infectious complications in acquired immunodeficiency syndrome

Infectious complications are the most common cause of death in patients with acquired immunodeficiency syndrome (AIDS). Opportunistic infections associated with defects in both T and B lymphocyte function have been observed. Invasive infections, including those secondary to procedures both in and out of the hospital, must also be considered. Reliance on serologic antibody tests is ill-advised since antibody response is often not effective. Since simultaneous infections frequently develop in patients with AIDS, attempts to identify pathogens by culture and histopathology should be aggressive and thorough. With rapid diagnosis and therapy, many of the infections will respond. Prolonged treatment is indicated as recrudescence is common.

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.

Pathogenesis of lentivirus infections

Following infection of animals or humans, lentiviruses play a prolonged game of hide and seek with the host's immune system which results in a slowly developing multi-system disease. Emerging knowledge of the disease processes is of some relevance to acquired immune deficiency syndrome (AIDS), which is caused by a virus possessing many of the characteristics of a lentivirus.

Identification and characterization of conserved and variable regions in the envelope gene of HTLV-III/LAV, the retrovirus of AIDS

To determine the extent and nature of genetic variation present in independent isolates of HTLV-III/LAV, the nucleotide sequences of the entire envelope gene and parts of gag and pol were determined for two AIDS viruses. The results indicated that variation throughout the viral genome is extensive and that the envelope gene in particular is most highly variable. Within the envelope, changes were most prevalent within the extracellular region where clustered nucleotide substitutions and deletions/insertions were evident. Based on predicted secondary protein structure and hydrophilicity, these hypervariable regions represent potential antigenic sites. In contrast to the hypervariable regions, other sequences in the extracellular envelope and the overall envelope structure (including 18 of 18 cysteine residues), as well as most of the transmembrane region, were highly conserved.

The AIDS dementia complex: I. Clinical features

Of 70 autopsied patients with the acquired immune deficiency syndrome (AIDS), 46 suffered progressive dementia that was frequently accompanied by motor and behavioral dysfunction. Impaired memory and concentration with psychomotor slowing represented the most common early presentation of this disorder, but in nearly one half of the patients either motor or behavioral changes predominated. Early motor deficits commonly included ataxia, leg weakness, tremor, and loss of fine-motor coordination, while behavioral disturbances were manifested most commonly as apathy or withdrawal, but occasionally as a frank organic psychosis. The course of the disease was steadily progressive in most patients, and at times was punctuated by an abrupt acceleration. However, in 20% of patients a more protracted indolent course was observed. In the most advanced stage of this disease, patients exhibited a stereotyped picture of severe dementia, mutism, incontinence, paraplegia, and in some cases, myoclonus. The high incidence and unique clinical presentation of this AIDS dementia complex is consistent with the emerging concept that this complication is due to direct brain infection by the retrovirus that causes AIDS.

Safe disinfection of contact lenses after contamination with HTLV-III

The human T-lymphotropic retrovirus type III (HTLV-III), the etiological agent of AIDS, has recently been detected in tears, cornea, and conjunctiva, raising the possibility of transmission of HTLV-III via contact lens trial sets used in routine fitting. We evaluated the ability of several contact lens cleaning solutions, with or without conditioning or disinfecting solutions, to disinfect contact lenses experimentally contaminated with HTLV-III. Following attempted disinfection, the lenses were cultured for residual HTLV-III on Hg cells for 28 days. Cultures without characteristic cytopathic effects, reverse transcriptase activity, and HTLV-III-specific antigen expression were considered negative. We found that all commercially available cleaning solutions tested were able to disinfect contact lenses exposed to HTLV-III.

The AIDS dementia complex: II. Neuropathology

In order to define the histopathological substrate of the dementia that frequently complicates the acquired immune deficiency syndrome (AIDS), we analyzed the neuropathological findings in 70 autopsied adult AIDS patients, 46 of whom had suffered clinically overt dementia. Less than 10% of the brains were histologically normal. Abnormalities were found predominantly in the white matter and in subcortical structures, with relative sparing of the cortex. Their frequency and severity generally correlated well with the degree and duration of clinical dementia. Most commonly noted was diffuse pallor in the white matter, which in the pathologically milder cases was accompanied by scanty perivascular infiltrates of lymphocytes and brown-pigmented macrophages, and in the most advanced cases by clusters of foamy macrophages and multinucleated cells associated with multifocal rarefaction of the white matter. However, in nearly one third of the demented cases the histopathological findings were remarkably bland in relation to the severity of clinical dysfunction. In addition, similar mild changes were noted in over one half of the nondemented patients, consistent with subclinical involvement. Vacuolar myelopathy was found in 23 patients and was generally more common and severe in patients with advanced brain pathology. Evidence of cytomegalovirus (CMV) infection was noted in nearly one quarter of the brains and was associated with a relative abundance of microglial nodules, but correlated neither with the major subcortical neuropathology nor with the clinical dementia, indicating that CMV infection likely represented a second, superimposed process. This study establishes the AIDS dementia complex as a distinct clinical and pathological entity and, together with accumulating virological evidence, suggests that it is caused by direct LAV/HTLV-III brain infection.