Transient antibody to lymphadenopathy-associated virus/human T-lymphotropic virus type III and T-lymphocyte abnormalities in the wife of a man who developed the acquired immunodeficiency syndrome

Three cases of HIV-1 seroreversion

Three patients were enrolled, two as hemophiliacs, and one with acute EBV infection. Serial serum samples of each patient were tested with at least 3 different HIV antibody EIA tests, an immunofluo-rescent test and two western blots (WB). In the third case, PCR and reverse transcriptase enzyme activity measurement were also done. One of the regularly checked serum samples of hemophiliac patients was reactive with different HIV screening and confirmatory assays. Their next blood samples, two weeks and one month later, respectively, were negative with the same tests. In Case 3. two and a half years after the first examination, the EIA tests results changed to negative, but the WB was still indeterminate. In the case of the two hemophiliac patients, the patients may have been exposed to HIV containing blood products (before 1985), but were not infected. Regular treatment with factor VIII concentrate, in which HIV antigens may be present, can boost the immune response and results in transient seropositivity. In the case of the EBV infected patient, the transient HIV seropositivity may be the consequence of EBV induced proliferation of anti-HIV-antibody producing B cell clones. During our ten year HIV confirmatory practice we tested more than 40000 samples, from which transient seropositivity were observed only in the three cases summarized in this paper.

The effects of early antiretroviral therapy and its discontinuation on the HIV-specific antibody response

HIV-specific antibodies become detectable and continue to increase in frequency during primary infection. The effects of early antiretroviral treatment (ART) and its discontinuation on the evolution of this immune response have not been systematically analyzed. To investigate the associations between antibody titer, viral load, and ART, we used a less-sensitive enzyme-linked immunosorbant assay (LS-EIA) to measure changes in HIV-1-specific antibody levels in treated and untreated subjects undergoing primary infection. In this longitudinal study, antibody levels gradually increased in therapy-naive subjects, reaching a plateau approximately 40 weeks postinfection. In contrast, antibody titers remained low among subjects receiving ART. Subjects who discontinued ART exhibited a more rapid rise in antibody titers than therapy-naive subjects, suggesting the presence of an enhanced B cell response. These results demonstrate that early ART prevents the typical evolution of the HIV-1-specific antibody response and can alter the expected kinetics of this response in subjects discontinuing therapy.

Transient or occult HIV infections may occur more frequently than progressive infections: changing the paradigm about HIV persistence

Evidence of transient HIV infections was found in 8 subjects at high-risk for HIV infection among 47 longitudinally studied over 2-5 (average approximately 3.5) years, whereas only two subjects developed progressive infection. All of these subjects developed serum antibodies (Ab) to conformational epitopes of HIV gp41 (termed "early HIV Ab"), but the 8 transiently infected subjects lost this Ab within 4-18 months, and did not seroconvert to positivity in denatured antigen EIA or Western Blot (WB). However, the two progressively infected subjects eventually seroconverted in the EIA and WB tests within one to two months after the appearance of "early HIV Ab". HIV env and nef sequences were directly PCR amplified from the peripheral blood mononuclear cells (PBMCs) of two of the eight transiently infected subjects during the time of "early HIV Ab"-postivity, and these showed significant sequence divergence from the HIV strains in the laboratory, indicating that they were not laboratory contaminants. Genome identity typing ("paternity-typing") of PBMC samples obtained at the time of "early HIV Ab"-positivity, and later when Ab was absent from each of the 8 subjects, showed that blood samples were not mixed-up. This provides further evidence that transient or occult infection with HIV does occur, and perhaps at a greater frequency than do progressive infections.

Feline immunodeficiency virus clade C mucosal transmission and disease courses

The transmissibility and pathogenicity of a clade C feline immunodeficiency virus (FIV-C) was examined via the oral-nasal, vaginal, or rectal mucosa. FIV-C was transmissible by all three mucosal routes. Vaginal transmission was most efficient (100%), oral exposure resulted in a 80% infection rate, and rectal transmission was least effective (44%). In contrast to previous intravenous passage studies, a broader range of host-virus relationships was observed after mucosal exposure. Three categories of FIV-C infection were defined: (1) rapidly progressive infection marked by high virus burdens and rapid CD4+ cell depletion (43% of vaginally exposed animals); (2) conventional (typical) infection featuring slowly progressive CD4+ cell decline (61% of all exposed animals); and (3) regressive (transient) infection marked by low and then barely detectable virus burdens and no CD4+ cell alterations (22% of rectally inoculated cats). These disease courses appear to have parallels in mucosal HIV and SIV infections, emphasizing the importance of the virus-mucosa interface in lentiviral pathogenesis.

Loss of Gag-specific antibody reactivity in cattle experimentally infected with bovine immunodeficiency-like virus

The development and persistence of virus-specific antibodies were investigated in eight cattle experimentally infected with the R29 isolate of bovine immunodeficiency-like virus (BIV). By 4 weeks postinoculation (p.i.), antibodies reactive to BIV gag- and env-encoded recombinant fusion proteins were detectable by immunoblotting in all animals. By 40 weeks p.i., seven of eight cattle had dramatically decreased Gag-specific antibodies, and anti-Gag reactivity remained very low or undetectable through 190 weeks p.i. Immunoprecipitation experiments revealed a similar loss of reactivity to nondenatured BIV Gag in these animals. In contrast, antibodies to a recombinant BIV Env protein were readily detectable throughout the study in all eight cattle. During the period of declining Gag antibody, infectious virus was recoverable from peripheral blood mononuclear cells of each animal. However, there was no evidence for sufficient amounts of BIV p26-containing immune complexes to explain the loss of anti-Gag reactivity. Interestingly, the single animal that maintained detectable anti-Gag reactivity throughout the study was repeatedly negative for virus recovery beyond 17 weeks p.i. All animals have remained clinically normal for over 4 years p.i., with no evidence of consistent changes in mononuclear cell subsets. These findings provide evidence that in BIV infection an early decline in Gag-specific antibody reactivity can occur without evidence of increasing viral replication or progression to overt clinical disease.

Five myths about AIDS that have misdirected research and treatment

A number of widely repeated and factually incorrect myths have pervaded the AIDS research literature, misdirecting research and treatment. Five of the most outstanding are: 1) that all risk groups develop AIDS at the same rate following HIV infection; 2) that there are no true seroreversions following HIV infection; 3) that antibody is protective against HIV infection; 4) that the only way to treat AIDS effectively is through retroviral therapies; and 5) that since HIV is so highly correlated with AIDS incidence, it must be the sole necessary and sufficient cause of AIDS. A huge body of research, reviewed in this paper, demonstrates the falsity of these myths. 1) The average number of years between HIV infection and AIDS is greater than 20 years for mild hemophiliacs, 14 years for young severe hemophiliacs, 10 years for old severe hemophiliacs, 10 years for homosexual men, 6 years for transfusion patients of all ages, 2 years for transplant patients, and 6 months for perinatally infected infants. These differences can only be explained in terms of risk-group associated cofactors. 2) Seroreversions are common. Between 10 and 20 percent of HIV-seronegative people in high risk groups have T-cell immunity to HIV, and may have had one or more verified positive HIV antibody tests in the past. 3) Antibody, far from being protective against HIV, appears to be highly diagnostic of loss of immune regulation of HIV, and some evidence of antibody-enhancement of infection exists. 4) Non-retroviral treatments of HIV infection, including safer sex practices, elimination of drug use, high nutrient diets, and limited reexposure to HIV and its cofactors have proven to be effective means of preventing or delaying onset of AIDS. 5) Many immunosuppressive factors, including drug use, multiple concurrent infections, and exposure to alloantigens, are as highly correlated with AIDS risk groups as HIV. These data are more consistent with AIDS being a multifactorial or synergistic disease than a monofactorial one.

Is a positive western blot proof of HIV infection?

It is currently accepted that a positive Western blot (WB) HIV antibody test is synonymous with HIV infection and the attendant risk of developing AIDS. In this communication we present a critical evaluation of the presently available data on HIV isolation and antibody testing. This evidence indicates that: (1) the antibody tests are not standardized; (2) the antibody tests are not reproducible; (3) the WB proteins (bands) which are considered to be encoded by the HIV genome and to be specific to HIV may not be encoded by the HIV genome and may in fact represent normal cellular proteins; (4) even if the proteins are specific to HIV, because no gold standard has been used to determine specificity, a positive WB may represent nothing more than cross-reactivity with non-HIV antibodies present in AIDS patients and those at risk. We conclude that the use of antibody tests as a diagnostic and epidemiological tool for HIV infection needs to be reappraised.

Lymphocytes from some long-term seronegative heterosexual partners of HIV-infected individuals proliferate in response to HIV antigens

A comparison of the proliferative responses of lymphocytes to human immunodeficiency virus (HIV) antigens from long-term, seronegative heterosexual partners of HIV-infected subjects, from normal unexposed controls and from healthy seropositive heterosexual partners or seropositive, asymptomatic men, reveals that lymphocytes from healthy seropositive individuals with strong proliferative responses to recall, microbial antigens respond only minimally to HIV proteins or envelope peptides, and that even these low responses do not occur in all individuals. If the frequency of responses to several HIV antigens are analyzed, lymphocytes from both HIV-exposed seropositive and seronegative partners of infected individuals proliferate to HIV antigens to a greater degree than lymphocytes from unexposed, normal control individuals. Although lymphocytes from seropositive partners proliferate to a greater degree than those from seronegative partners, the latter are more similar to seropositive partners than they are to normal controls. This observation suggests that these seronegative partners may have become sensitized to HIV antigens through sexual exposure but without infection, and/or that the presence or development of these small immune responses in some individuals might be associated with a failure to become infected.

Eliminating human immunodeficiency virus (HIV) from infected individuals and cells: is it possible?

The literature from 1984 to 1991 has been searched for reports of patients who have eliminated human immunodeficiency virus (HIV) from their system. While such reports are scarce, it appears that a small number of HIV-positive patients have reverted to a negative state either spontaneously or following radical immunosuppressive regimens for neoplastic disease. Although no carefully planned animal experiments or clinical trials have been reported, it would appear that bone marrow ablation and replacement may eliminate HIV from healthy, asymptomatic HIV-positive individuals. Although much of the clinical experience to date suggests that radical immunosuppression is not indicated in advanced AIDS patients in whom the virus has likely spread beyond the immune system, such cases do not represent evidence that immunosuppression is not indicated in healthy, HIV-positive individuals.

Polymorphic human gene(s) determines differential susceptibility of CD4 lymphocytes to infection by certain HIV-1 isolates

Independent isolates of HIV-1 differ widely in their tropisms for CD4-positive T-cell lines. This study demonstrates that tropisms of 10 different HIV-1 isolates also differ widely, as much as 1000-fold, for normal peripheral blood lymphocytes (PBLs) cultured from any given donor. This could only be reproducibly demonstrated by end point titrations. In addition, the degree of susceptibility of PBLs from 12 random donors to productive infection by any given HIV-1 isolate also varied in a reproducible pattern from donor to donor, with some donors relatively resistant to one or a few isolates. The HIV susceptibility pattern of each donor was manifested at the level of the CD4 lymphocyte and it segregated within a family, conclusively demonstrating that it was genetically determined.

HIV-1 infection in haemophilia

Guidelines have been prepared by the National Hemophilia Foundation, USA, for treating patients with haemophilia, these are: 1. General recommendations. The risks of withholding treatment far outweigh risks of treatment. Patients should however be educated to use appropriate clotting factor doses to minimize overuse and contain costs. 2. Factor VIIIC-deficient patients. DDAVP should be used whenever possible by patients with mild or moderate factor VIIIC deficiency. When feasible, an alternative to concentrates may be the use of cryo-precipitate prepared from one well-screened donor or from a small number of such donors. (a) Prevention of hepatitis. Hepatitis B vaccination is essential for uninfected patients. Preliminary data suggest that products that are pasteurized, solvent/detergent-treated or monoclonal antibody-purified are at a reduced risk of transmitting hepatitis viruses. (b) Prevention of HIV-1. Concentrates pasteurized, treated with solvent/detergent, purified with monoclonal antibody, heated in suspension with organic solvents, or dry heat-treated for long periods are preferred. These products carry a substantially reduced risk of transmitting HIV-1. 3. Factor IX deficiency. For patients with severe deficiency the use of virus-inactivated Factor IX concentrate is recommended. For mild to moderate patients when feasible an alternative would be fresh, frozen plasma prepared from one well-screened and repeatedly-tested donor or from a small number of such donors. In the past few years, significant progress has been made in understanding the nature of the defect in haemophilia both at the molecular and structural levels, such a foundation is necessary for definitive treatments in the future. For now, however, the dark side of replacement therapy must be accepted along with its benefits.

Anti-HIV antibody testing: procedures and precautions

Prudent use of screening tests for infection with human immunodeficiency virus (HIV) and interpretation of test results require an understanding of the body's immune response to HIV infection, the serologic assays currently available, and the problems associated with false-positive and false-negative test results. The methodologies of the enzyme immunoassay (enzyme-linked immunosorbent assay [ELISA]) and the Western blot assay are presented, and efficacies of these tests are evaluated. Tests for the detection of anti-HIV antibodies that are, at this time, primarily restricted to research use but that show promise for adaptation to screening (such as the ELISA with recombinant antigen) also are discussed, as is the alternative of testing for HIV antigens or HIV-specific DNA. From a personal perspective, any test for HIV infection is accompanied by certain benefits and risks. These can be discussed with the patient in the framework of pretest and posttest counseling.

The clinical spectrum of the HIV infection. A working hypothesis

Many clinicians have realised that AIDS is only the most dreadful aspect of HIV infection. Together with the "asymptomatic carrier" condition, other syndromes have been described, including LAS, ARC and Lesser-AIDS. We have developed a working hypothesis to explain the natural history of HIV infection, basing our assumptions on the international literature and our own experience. We have found many analogies and some slight differences between the clinical courses of HIV infection and other chronic infections, especially syphilis. It is possible that, on clinical grounds, the natural histories of both diseases are so similar as to allow us to describe one of them within the scheme of the other. Only careful and prolonged clinical observation will solve the problem of the natural history of HIV infection and solve the problems which are still present in its comprehension.

Seroconversion to human immunodeficiency virus (HIV) in hemophiliacs. Relation to lymphadenopathy

The authors studied the natural history of human immunodeficiency virus (HIV) exposure in 187 hemophiliacs followed for an average of 45 months. Overall, 55 percent developed antibody specific for HIV and 21 percent developed persistent generalized lymphadenopathy. Most patients seroconverted sometime between early 1982 and the end of 1984. Four patients developed acquired immune deficiency syndrome (AIDS) and four seropositive patients developed idiopathic thrombocytopenia (ITP). One of the four patients who developed AIDS and three of the four with ITP had preexisting lymphadenopathy. None of the 10 patients with lymphadenopathy or the 20 asymptomatic patients was seropositive for human T-lymphotropic virus, type I. Although seropositivity and lymphadenopathy have been found in many of the authors' patients, few have developed clinical disease that can be related to HIV infection.

Human-immunodeficiency-virus infections in infants negative for anti-HIV by enzyme-linked immunoassay

Of 85 children with human-immuno-deficiency-virus (HIV) infection based on clinical (opportunistic infection), epidemiological (mother a drug addict or known to be HIV infected), and immunological (helper-T-cell deficiency and impaired proliferative response to pokeweed mitogen) features, 9 were found to lack antibody to HIV as measured by a commercial enzyme-linked immunoassay (ELISA). All 9 children had detectable levels of HIV antigen in simultaneous plasma specimens, measured by a sensitive antigen-capture ELISA. The use of the western blot assay and an ELISA with recombinant HIV antigens was able to identify HIV infection in 4 of the 9 children.

Public awareness of AIDS in Rwanda

AIDS is a rapidly growing epidemic in Kigali, Rwanda. To understand the level of public awareness of AIDS in that city, 33 informants (15 men and 18 women) were interviewed during September, 1985. Most (66.7%) said that they first heard of the disease only within the previous eight months. About half (46.9%) could not mention one or more AIDS symptoms. Younger informants and women reported less knowledge of AIDS symptoms. While nearly everyone recognized AIDS as a stigmatized disease, most informants apparently did not know why it is stigmatized. Only about one-third of the informants (34.4%) could correctly state the mode of AIDS transmission. People who are at greatest risk for the disease, unmarried men and women, were least likely to know how it is transmitted. Half (50.0%) of those informants who responded to the question of the origins of AIDS said that it began in 'America.' While many informants are frightened by the disease, no one has yet changed their sexual behavior as a response to the epidemic. All informants agreed that more information about AIDS should be made available in Rwanda. Preventive measures against the spread of AIDS are urgently needed in central Africa.

Screening for HIV infection: risks, benefits, and the burden of proof

In 1984, scientists isolated a new pathogen, now called human immunodeficiency virus (HIV), that is almost certainly the etiological agent for the acquired immunodeficiency syndrome (AIDS). It has been estimated that there are between 500,000 and 1,750,000 asymptomatic, chronically HIV-infected individuals in the United States. In a remarkably short time, investigators developed a number of blood tests that indicate whether an individual is likely to be infected with this virus. These assays are now being used to test patients with symptoms suggesting AIDS or related syndromes, to screen donated blood, to evaluate individuals concerned about their infection status, and to screen new military recruits, active-duty soldiers, and ROTC students. Almost weekly, new proposals are advanced for screening different subsets of the population.

Persistent infection of chimpanzees with human T-lymphotropic virus type III/lymphadenopathy-associated virus: a potential model for acquired immunodeficiency syndrome

The lymphadenopathy-associated virus (LAV) prototype strain of human T-lymphotropic virus type III/LAV was transmitted to juvenile chimpanzees with no prior immunostimulation by (i) intravenous injection of autologous cells infected in vitro, (ii) intravenous injection of cell-free virus, and (iii) transfusion from a previously infected chimpanzee. All five animals that received more than one 50% tissue culture infective dose were persistently infected with LAV or chimpanzee-passaged LAV for up to 18 months. During this time they developed no illnesses, but they exhibited various degrees of inguinal and axillary lymphadenopathy and significant reductions in rates of weight gain. Detailed blood chemistry and hematologic evaluations revealed no consistent abnormalities, with the exception of immunoglobulin G (IgG) hypergammaglobulinemia, which became apparent in one animal 6 months postinfection and continued at more than 1 year postinfection. Transient depressions followed by increases in the numbers of T4 cells to levels greater than normal were observed in all animals after virus inoculation. However, the number of LAV-infected peripheral blood cells decreased with time after infection. Results of enzyme immunoassays showed that all infected animals seroconverted to IgG anti-LAV within 1 month postinfection and that antibody titers remained high throughout the period of observation. In contrast, only three of the five LAV-infected chimpanzees had detectable IgM antibody responses, and these preceded IgG-specific serum antibodies by 1 to 2 weeks. Virus morphologically and serologically identical to LAV was isolated from peripheral blood mononuclear cells of all infected animals at all times tested and from bone marrow cells taken from one animal 8 months after infection. One chimpanzee that was exposed to LAV only by sharing a cage with an infected chimpanzee developed lymphadenopathy and an IgM response to LAV, both of which were transient; however, no persistent IgG antibody response to LAV developed, and no virus was recovered from peripheral blood cells during a year of follow-up. Thus, LAV readily infected chimpanzees following intravenous inoculation and persisted for extended periods despite the presence of high titers of antiviral antibodies. However, the virus was not easily transmitted from infected to uninfected chimpanzees during daily cage contact.