Perinatal transmission of the human immunodeficiency virus type 1 to infants of seropositive women in Zaire

Human immunodeficiency virus type 1 infection of human placenta: potential route for fetal infection

To determine the potential role of the placenta in transmission of human immunodeficiency virus (HIV) from mother to fetus, the ability of human placental tissue to support HIV type 1 (HIV-1) infection was examined. HIV-1-seronegative first-trimester placentas were maintained in culture and infected with HIV-1. Virus production, measured by HIV-1 antigen release into the supernatant, and HIV-1 DNA, identified by polymerase chain reaction, were detected for at least 12 days postinfection. Western immunoblot analysis showed Gag proteins, precursor p55, and cleavage products p24 and p17 in HIV-1-infected tissues. Double labeling of placental villi with antibodies to CD4 and placental trophoblast-specific alkaline phosphatase indicated that trophoblasts express CD4 antigen. Additionally, immunostaining of HIV-1-infected tissues with anti-p24 antibodies demonstrated HIV-1 protein expression in placental trophoblasts. Evaluation of human chorionic gonadotropin and progesterone production by the placental cultures indicated that there was a 90% decrease in human chorionic gonadotropin and a 70% decrease in progesterone production in HIV-1-infected cultures in comparison with controls. These data demonstrate that trophoblastic cells of human placenta tissue express CD4 and are susceptible to HIV-1 infection; also, placental endocrine function is decreased by HIV-1 infection. Thus, the placenta may serve as a reservoir of HIV-1 infection during pregnancy contributing to infection of the fetus, and decreased placental hormone production may result in impaired fetal development.

A retrospective cohort study of the risk of tuberculosis among women of childbearing age with HIV infection in Zaire

To determine the risk of active tuberculosis associated with HIV infection, we retrospectively studied a cohort of HIV-seropositive and HIV-seronegative women participating in an HIV perinatal transmission study in Kinshasa, Zaire. After a median follow-up of 32 months, new cases of proven pulmonary or clinically diagnosed tuberculosis occurred in 19 of the 249 HIV-seropositive women (7.6%, 3.1 cases per 100 person-years) compared with 1 of the 310 HIV-seronegative women (0.3%, 0.12 cases per 100 person-years), for a relative risk of 26 (95% confidence interval, 5 to 125). Proven pulmonary tuberculosis was diagnosed in 7 HIV-seropositive women (2.8%, 1.2 cases per 100 person-years) and 1 HIV-seronegative woman (0.3%, 0.12 cases per 100 person-years), for a relative risk of 10 (95% confidence interval, 1.5 to 47). We estimated that 66 cases of proven pulmonary tuberculosis in 100,000 person-years of follow-up in women of childbearing age could be attributed to HIV; this is 35% of their estimated total incidence of proven pulmonary tuberculosis. Among those followed for 2 yr, 27 (11%) of 243 HIV-seropositive women died during 2 yr of follow-up compared with none of 296 HIV-seronegative women (p less than 0.001). In HIV-seropositive women with proven or clinically diagnosed tuberculosis mortality was even higher: 5 (26%) of the 19 HIV-seropositive women with proven pulmonary or clinically diagnosed tuberculosis died during follow-up compared with 22 (10%) of the 224 HIV-seropositive women not diagnosed as having tuberculosis (relative risk 2.7; 95% confidence interval, 1.1 to 6.3).(ABSTRACT TRUNCATED AT 250 WORDS)

A hospital-based prospective study of perinatal infection with human immunodeficiency virus type 1

Most infants with pediatric acquired immunodeficiency syndrome and infections with human immunodeficiency virus type 1 (HIV-1) are infected perinatally by their mothers. To determine the proportion of exposed infants who are infected, we conducted a hospital-based prospective study in HIV-1-infected women whose infants were delivered at a single metropolitan hospital in Miami, Fla. A population of uninfected women and their infants was also enrolled and followed longitudinally for 2 years to assess laboratory and clinical measurements. The median follow-up is now 18 months for 82 infants born to HIV-1-infected mothers. The proportion of infected infants in this group is 0.30 (25/82). None of the infants born to 110 HIV-1-seronegative mothers were seropositive. Infected infants were easily distinguished from noninfected infants by virus isolation. No single immunologic or hematologic measure was predictive of infection for all infants at risk for HIV-1 infection who were 6 months of age or younger. As a group, however, infected infants could be distinguished from uninfected index infants by a number of immunologic measures by 6 months of age; the absolute number of CD4+ lymphocytes and the CD4+/CD8+ lymphocyte ratio were the variables most predictive of infection. As in retrospective studies, clinical disease developed in 80% of infected infants within the first 24 months of life. This study provides documentation of HIV-1 perinatal transmission risk and early correlates of infection in young infants from a single hospital.

Repeated polymerase chain reaction complementary to other conventional methods for early detection of HIV infection in infants born to HIV-infected mothers

The efficacy of a polymerase chain reaction (PCR) method for early detection of human immunodeficiency virus (HIV) in infants at risk for HIV infection was assessed. The PCR method was added to the routine laboratory test programme in these patients in 1988. PCR was performed in a total of 26 children at risk (age range 2 days to 58 months), including 17 infants born to HIV-infected mothers, who were followed up clinically from the time of birth for a mean period of 23 months (range 6 to 54) in a prospective study. Twelve children were PCR-positive. Eight had AIDS, ARC or symptoms suggestive of HIV infection. All these patients had at least one culture positive for HIV (6/8) and/or one positive serum p24-antigen test (5/8). One child was repeatedly PCR positive, but asymptomatic as well as virus- and antigen-negative. Three asymptomatic children with a single positive PCR result were PCR negative in subsequent tests. Fourteen children with negative PCR did not show clinical or immunological signs suggestive of HIV infection. Their cultures for HIV and antigen-p24 assays were negative. It is concluded that in addition to clinical and immunological parameters PCR is a useful technique for diagnosis of HIV infection in infants born to HIV-infected mothers. However, in case of negative HIV cultures and/or serum p24-antigen tests, single positive PCR results in asymptomatic patients must be interpreted with caution and should be confirmed by repeated tests.

Replication of human immunodeficiency virus type 1 in primary cultured placental cells

The role of placental cells in transplacental transmission of human immunodeficiency virus type 1 (HIV 1) was investigated. Placental macrophages and trophoblasts, which together represent the main cell components of the placenta, were cultivated separately and then compared to foetal monocyte-derived macrophages for susceptibility to HIV 1 infection. Placental macrophages treated with granulocyte-macrophage colony-stimulating factor (GM-CSF) were less easily infected with HIV 1 than were GM-CSF-treated foetal monocyte-derived macrophages. HIV 1 replication in cocultures consisting of infected placental macrophages together with a highly HIV 1-permissive cell line (CEM) was detected persistently for at least 6 weeks by reverse transcriptase assay, even though placental macrophages expressed no detectable CD4 receptor, as indicated by indirect immunofluorescence. HIV 1-specific DNA sequences were also detected in infected placental macrophages. Trophoblasts exhibited no detectable CD4 expression and did not support the replication of HIV 1, although low levels of HIV 1-specific DNA sequences could be detected in infected trophoblasts. Placental macrophages or trophoblasts (or both) may thus play an important role in transplacental HIV 1 transmission.

Epidemiology of pediatric HIV infection

Perinatal transmission of human immunodeficiency virus (HIV) continues to increase. In 1989 alone, it is estimated that 1750 infected children were born in the United States. Although transmission is spreading to areas outside the cities originally most affected, these cities continue to bear the greatest toll. Adolescents may be particularly vulnerable to HIV infection; education and counseling are critical for controlling the epidemic in this age group.

Pediatric HIV disease. The newest chronic illness of childhood

HIV disease has emerged as a major chronic illness of childhood. Children with HIV infection and children with other chronic health impairments have much in common, including the need for comprehensive, multidisciplinary, coordinated care that includes special attention to the psychosocial effects on the child and family. However, because the mother and often the father and siblings share this lethal viral infection, the impact of HIV disease upon the family surpasses that of virtually all other chronic conditions. This is compounded by the association of the disease with drug use, its preponderance among the most disenfranchised populations in the United States, and the persistent public fear and discrimination surrounding AIDS. We have made substantial progress already in the medical management of this infection, and while we await the development of more effective therapies, we already have the tools and knowledge in hand to help these families.

Medical care of the HIV-infected child

Familiarity with the demographics of pediatric HIV disease and recognition of common and uncommon presentations of infection are keys to diagnosing the HIV-infected child. Subsequent management entails preventative care, including immunizations and nutritional support, as well as management of HIV-related complications.

AIDS-related knowledge, sexual behavior, and condom use among men and women in Kinshasa, Zaire

This study was conducted in 1988 among a random sample of 6,625 men and women of reproductive age in all 24 administrative zones of Kinshasa, the capital city of Zaire, to determine existing levels of knowledge regarding AIDS (acquired immunodeficiency syndrome), sexual behavior, knowledge and use of condoms in marital and extramarital relations; perceived risk of AIDS, and attitudes toward testing for the human immunodeficiency virus (HIV). Awareness of AIDS is almost universal, and the vast majority know the four main modes of transmission. Almost half believed in transmission by mosquitoes and in a vaccine or cure for AIDS. The majority of male respondents knew of condoms, but negative attitudes toward condom use are widespread, and few respondents perceived them to play a central role in combatting AIDS.

Ethical, methodological and political issues of AIDS research in Central Africa

AIDS represents research challenges for anthropology as well as for biomedicine. In many ways the dilemmas of anthropologists appear to be of lesser magnitude than those confronting biomedical researchers charged with the responsibility for treating patients and searching for cures and vaccines. Yet anthropological research is both politically sensitive and policy-relevant. Ethical practice in anthropology is linked to questions of methodology and theory which this article explores based on the author's leadership of CONNAISSIDA, a collaborative action-research team studying the medical anthropology of AIDS in Zaire from 1985 to 1990. The need for a broad approach to social research in support of AIDS prevention is argued.

How can epidemiology assist in guiding interventions for the acquired immunodeficiency syndrome/human immunodeficiency virus?

In a single decade, the pandemic of human immunodeficiency virus (HIV) infection has become an international health, social, and economic emergency. Early and effective intervention is urgently needed for both prevention of HIV infection and for the amelioration of clinical disease. Results of therapeutic trials have suggested expanding the population for which chemotherapy is indicated. In this paper, we first review the findings from selected recent drug trials, using zidovudine and pentamidine as examples. We then discuss six issues that we believe to be crucial for future epidemiologic research in the service of vaccine and drug development: 1. To identify which complications of HIV infection most urgently require development of new therapies, we must characterize the frequency and severity of specific medical events (outcomes) in persons taking a variety of treatments. 2. Currently, acquired immunodeficiency syndrome (AIDS) therapeutic trials gauge the effectiveness of new therapies by their impact on such clinical parameters as the time to development of AIDS or death. These approaches take too long to provide information. We urgently need to identify surrogate markers of clinical outcome that will be useful in the early assessment of treatment efficacy. 3. Progress in vaccine development is being retarded because we do not have enough data from natural history studies on host immunologic responses to suggest that a given response is protective. We therefore need to identify natural correlates of immunity, which can help set priorities in vaccine development. 4. Discovery that a therapy works in the setting of a clinical trial is only a first step in intervention. We must also assess the impact of new therapies on the health of the public, evaluating access to health care, compliance, and other barriers to treatment. 5. Clinical trials are usually associated with the effort to prevent disease in infected persons. However, other trials are needed to assess efforts to interrupt viral transmission through use of condoms, use of virucides, and treatment of sexually transmitted diseases, and by effecting specific behavioral changes. 6. Traditional methods of conducting clinical therapeutic research may not be adequate to address urgent questions in the AIDS/HIV epidemic. We must develop innovative clinical research methods, including better use of data from observational studies, to infer what we can about the effect of treatment on the clinical course.

HIV-1 infection in a cohort of haemophilic patients

The course of HIV infection in 53 haemophilic patients aged 5-20 years was evaluated by clinical examination and laboratory tests. During the evaluation time (median 30 months) two patients died of AIDS and 32 patients (60%) deteriorated when assessed by the Brodt-Helm classification. Nineteen patients (37%) had decreased absolute helper cell counts (less than 500 CD4 positive cells/microliters), and 45 patients (87%) had reduced helper cell to lymphocyte ratios (less than 0.35). HIV-1 was isolated from peripheral lymphocytes in 29 of 46 patients. As the disease progressed the number of positive viral cultures increased. Considerable progression of the HIV infection was seen in haemophilic children and adolescents during the median evaluation period of 30 months. The transition from symptomless HIV infection to immunodeficiency was easily recognised. A lowered ratio of helper cells to lymphocytes seems to be a useful marker of the beginning of the deterioration of the immune system.

Detection of anti-HIV IgA in tears of children born to seropositive mothers is highly specific

In order to improve the diagnosis of HIV infection in children born to seropositive mothers, 86 children were previously tested by Western blotting for anti-HIV IgA in tears and IgG in serum, at a median age of 9.2 months. To determine the exact value of the assay, 68/86 children of the same cohort were retested 9 months later. Nine children (13.4%) were seropositive and all had anti-HIV IgA in tears. Eight of them had possessed lachrymal antibodies 9 months earlier. The ninth child was seronegative when 9 months old and then seroconverted. Four children (6%), known to be seronegative, had an indeterminate Western blot pattern and no HIV IgA in tears. Fifty four (80.6%) were seronegative at 18 months; none of them had ever had anti-HIV IgA in tears. This highlights the fact that only the children without lachrymal HIV IgA at the age of 9 months became seronegative at the age of 18 months. Our results clearly show that the detection of anti-HIV IgA in tears is a highly specific and reliable diagnostic test in children aged less than 15 months, born to seropositive mothers.

Transplacental transfer of zidovudine in the near-term pregnant baboon

Approximately one third of infants born to human immunodeficiency virus type 1 seropositive mothers have evidence of infection or of acquired immunodeficiency syndrome by the age of 18 months. One fifth of infected infants also have died by age 18 months. This prevalence, combined with the demonstration that zidovudine (formerly azidothymidine) can decrease mortality and the frequency of opportunistic infections in patients with acquired immunodeficiency syndrome or acquired immunodeficiency syndrome--related complex, may lead to increasing use of azidothymidine in pregnancy despite a paucity of information regarding its pharmacokinetics. To further investigate the distribution of azidothymidine and its inactive metabolite 5'-glucuronide azidothymidine in the mother, fetus, and amniotic fluid, 12 near-term pregnant baboons were given oral azidothymidine (21 mg/kg/day in four divided doses every 6 hours, equivalent to the usual nonpregnant human dose of 1500 mg/day). Specimens of maternal blood, fetal arterial blood obtained by percutaneous umbilical cord blood sampling, and amniotic fluid were obtained after from one to 17 doses of azidothymidine. Azidothymidine levels were measured by radioimmunoassay with the INCSTAR commercial radioimmunoassay kit and using Escherichia coli beta-glucuronidase for determination of 5'-glucuronide azidothymidine levels. Paired analyses revealed significant concentration gradients between amniotic fluid, fetal serum, and maternal serum for both azidothymidine (p less than 0.019) and 5'-glucuronide azidothymidine (p less than 0.002). The amniotic fluid 5'-glucuronide azidothymidine level increased with increasing doses of azidothymidine despite the fact that the maternal azidothymidine and 5'-glucuronide azidothymidine concentrations were unchanged. This accumulation of amniotic fluid 5'-glucuronide azidothymidine may provide a functional drug reservoir and contribute to the higher fetal concentrations of the medication and its metabolite. Alternatively, the higher fetal levels may represent slower clearance in the fetus than in the mother. Further studies appear warranted with respect to possible adverse fetal effects, especially bone marrow suppression with prolonged and chronic exposure to azidothymidine.

Maternal and perinatal issues regarding HIV infection

A review of the information available regarding maternal and fetal factors involved in both protection from and infection with HIV raises more questions than answers. Although providing prevention of HIV infection in women and infants is the ultimate goal, the recent increases in HIV seroprevalence among women of childbearing age gives little hope that this approach will have an effect in the near future. Early detection of HIV infection in pregnant women may provide the opportunity to counsel, provide routine obstetric care, and consider early therapeutic intervention with antiretroviral therapy and active or passive immunotherapy. Identification of HIV-infected infants before they are symptomatic is an equally important goal, as similar therapeutic options may be used.

The impact and use of written leaflets as a counselling alternative in mass antenatal HIV screening

Pre-test counselling has been seen as a pre-requisite for HIV screening. As HIV moves into the heterosexual community, the role of HIV screening in ante-natal care has increased. As vertical transmission is the major contributor to perinatal infection HIV screening of pregnant women has become a reality. The pregnant population comprises large numbers, the practical difficulties of routine pre-test counselling and the informational demand from pregnant women themselves has necessitated the provision of ante-natal leaflets about HIV infection and AIDS. A survey of 24 London hospitals revealed only three leaflets in use, two from one hospital and one from an AIDS Charity. A content evaluation of the leaflets revealed varying readability, elements of bias and presentation factors which may all affect the usefulness of such leaflets. An in depth qualitative group on the leaflet with highest readability revealed particular concerns and highlighted the fact that the leaflets could be seen as additions and addendums to counselling but were not sufficient in themselves.

Long HIV-1 incubation periods and dynamics of transmission within a family

The incubation period of human immunodeficiency virus type 1 (HIV-1) infection was studied in a family of five in which vertical and heterosexual transmission occurred from one index case. This investigation documented incubation periods of longer than 12 years in a mother and her daughter; although neither has symptoms, both are definitely infected and have very low CD4(+)-lymphocyte counts. The study confirmed the predictions of incubation periods longer than 10 years in a small proportion of infected individuals. It provides evidence that vertically HIV-1-infected teenagers can be expected to appear in the population.

Gastroenterological aspects of AIDS in the Third World

Gastrointestinal disease is the commonest presentation of AIDS in the Third World. Diarrhoea and weight loss are particularly common. Although many pathogens may be found, chronic cryptosporidiosis is the most frequent and there remains no specific effective therapy. Isospora belli is found in less than 10% of cases, but may be treated with cotrimoxazole, and long-term maintenance treatment to prevent relapse is effective. Oral disease, especially with candidiasis, is increasingly recognized and may be controlled with topical antifungal agents. The outlook for patients in the Third World who present with gastrointestinal opportunistic infections associated with HIV infection is particularly dismal. Specific antiviral therapy, which has at least brought some hope and longer survival to patients in developed countries, remains largely unavailable in the Third World.

Vertical transmission of human immunodeficiency virus is correlated with the absence of high-affinity/avidity maternal antibodies to the gp120 principal neutralizing domain

Many, but not all, infants born to mothers infected with the human immunodeficiency virus (HIV) are infected in utero. We have now shown that mothers who have high-affinity/avidity antibodies directed toward the principal neutralizing domain (PND) of gp120 are less likely to transmit HIV to their children. An ELISA that preferentially measures the level of the biologically functioning, high-affinity/avidity antibodies against PND is described. In a retrospective study of 15 maternal/neonatal serum samples, the assay correctly identified the 4 uninfected and the 11 HIV-infected infants. Other clinical and laboratory parameters such as p24 antigen, phytohemagglutinin mitogenic index, and absolute surface antigen T4+ cell counts did not accurately predict HIV fetal transmission. In addition to introducing a promising diagnostic tool, this study provides the in vivo evidence that protective antibodies may prevent infection by HIV.

HIV-specific IgA antibodies in tears of children with AIDS or at risk of AIDS

To improve on the diagnosis of human immunodeficiency virus (HIV) infection, 14 children with clinical evidence of AIDS, 86 children less than 15 months old and born to seropositive mothers, and 29 controls were tested for the presence of IgA antibody in tears directed against HIV antigens on Western blots. IgA antibodies in tears against env- and pol-encoded proteins were present in 13 of 14 children with AIDS and in 13 of 86 children born to seropositive mothers. No HIV-specific IgA was observed in tears of the 29 controls. Among the 86 children less than 15 months old, 11 had clinical evidence of AIDS and 7 of them (64%) had HIV-specific IgA in tears. Results show that the demonstration of lacrimal HIV-specific IgA may help to distinguish between truly infected children and those whose HIV antibodies are passively transferred from the mother. Therefore, this simple method is a good tool for laboratory diagnosis of paediatric AIDS.

Epidemiology and clinical picture of human immunodeficiency virus type 1 infection and the acquired immune deficiency syndrome

Human Immunodeficiency Virus Type 1 (HIV-1) infection which causes the terminal Acquired Immune Deficiency Syndrome (AIDS) is one of the major new pandemics of this millenium. This infection is believed to be a zoonosis which achieved sustained transmission among humans because of recent increases in sexual promiscuity and needle-sharing drug use. Although the HIV-1 epidemic is of relatively recent onset, its modes of transmission have been clearly defined: sexual relations, blood injection, and childbirth. Other possible transmission methods such as non-sexual social interaction and insects have been explicitly excluded. Susceptibility is increased by genital ulcers and lack of male circumcision but probably not by genetic factors or female circumcision. Transmissibility is also increased by genital ulcers and, more importantly, by the stage of disease. Progression by stages to fatal diseases will probably occur in most, if not all, infected individuals, usually within a decade. While HIV-1 has a direct effect on the intestinal track and the central nervous system, its primary effect is suppression of the immune system resulting in overwhelming secondary infections and, less clearly, cancers. Human Immunodeficiency Virus Type 1 infection is incurable and is likely to remain so for the foreseeable future. Although life-prolonging treatments have been developed, a vaccine will likely not be available in the foreseeable future. Like most previous new epidemic diseases, HIV-1 infection is being and will continue to be modified by changing human behavior patterns.

Impact of HIV/AIDS on African children

In Central and East Africa, pediatric human immunodeficiency virus (HIV) infection and acquired immunodeficiency syndrome (AIDS) are becoming increasing threats to child health due to the predominance of heterosexual transmission of HIV, high HIV infection rates in women of reproductive age and high birth rates. This paper examines the potential impact of HIV/AIDS on orphanhood and under-five mortality in 10 Central and East African countries. The author estimates that, in the 10 countries studied, HIV/AIDS in children under age five will cause between one-quarter and half a million child deaths annually by the year 2000. Whereas the United Nations estimate (without AIDS) and target for the under-five mortality rate in this 10-country region by the year 2000 are 132 and 78, respectively, HIV/AIDS will cause the under-five mortality rate to rise to between 159 and 189. Increasing HIV/AIDS-related adult mortality is creating a large and growing number of children under age 15 whose mothers have died of HIV/AIDS. During the 1990s, HIV/AIDS will kill a total of between 1.5 and 2.9 million women of reproductive age in this region, producing between 3.1 and 5.5 million AIDS orphans--which means that between 6 and 11% of the population under age 15 will be orphaned. National and international government and nongovernment service providers in Central and East Africa need to recognize this potential impact of HIV/AIDS on children, expand AIDS-prevention efforts, and develop policies and programs to address children's HIV/AIDS-related needs.

Survival in children with perinatally acquired human immunodeficiency virus type 1 infection

We describe our experience at Jackson Memorial Hospital in Miami, Florida, with 172 children who were given diagnoses of perinatally acquired infection with human immunodeficiency virus type 1 (HIV-1). The 146 mothers of the children acquired HIV-1 through heterosexual contact (69 percent), intravenous drug use (30 percent), or blood transfusion (1 percent). The children presented with symptomatic disease at a median age of eight months; only 21 percent presented after the age of two years. The most common first manifestations of disease were lymphoid interstitial pneumonia (in 17 percent), encephalopathy (in 12 percent), recurrent bacterial infections (in 10 percent), and candida esophagitis (in 8 percent), for which the median survival times from diagnosis were 72, 11, 50, and 12 months, respectively. Nine percent of the children had Pneumocystis carinii pneumonia at a median age of five months and had a median survival of only one month. The median survival for all 172 children was 38 months from the time of diagnosis. Mortality was highest in the first year of life (17 percent), and by proportional-hazard analysis the probability of long-term survival is low. In multivariate analyses, early age at diagnosis and the first identifiable pattern of clinical disease were found to be independently related to survival. We conclude that children with perinatally acquired HIV-1 infection have a very poor prognosis and that most become symptomatic before one year of age. Early diagnosis is important, since there is only a short interval in which to initiate prophylactic or antiviral treatment before progressive disease begins.

Surveillance of AIDS and HIV infection: opportunities and challenges

Surveillance for AIDS/HIV infection is essential for planning, implementing and evaluating AIDS control programs. Each of the different methods used, AIDS surveillance, surveillance for HIV infection and HIV seroprevalence, sero-incidence studies in selected populations, have advantages and disadvantages. A combination of these methods is generally needed to accurately monitor the HIV epidemic, and the methods used will depend on the objectives of the surveillance system. Surveillance data need to be adequately analyzed and made available to the public, public health planners, health care professionals and politicians. Most importantly, surveillance data need to be used for preventive action.

Mother-to-infant transmission of human immunodeficiency virus type 1: association with prematurity or low anti-gp120

In a prospective study of pregnant women infected with human immunodeficiency virus type 1 (HIV-1) in Brooklyn, New York, USA, 16 (29%) of 55 evaluable infants were infected with HIV-1. 9 infants had paediatric acquired immunodeficiency syndrome, 6 had less severe clinical manifestations of HIV-1 infection, and 1 was symptom-free but was seropositive for HIV-1 beyond 15 months of age. The 10 infants born at 37 weeks of gestation or earlier were at higher risk of HIV-1 infection than infants born at 38 weeks of gestation or later (60% vs 22%) but the median age at appearance of disease was approximately 5 months in both groups. The HIV-1 transmission rate was not associated with predelivery levels of maternal T cells, anti-p24, or neutralising antibodies but it was higher, among full-term infants, for those with mothers in the lowest third of the distribution of anti-gp120 levels (53%). On immunoblot, transmitting mothers lacked a gp120 band but not other bands. Protection was not associated with antibody to recombinant peptides from the hypervariable region of the major neutralising gp120 epitope, and the anti-gp120 endpoint dilution titre was similar in transmitting and non-transmitting mothers. Mothers of uninfected full-term infants appear to confer immunological protection against HIV-1 infection of their offspring by way of a high-affinity antibody to a gp120 epitope, whose specificity has importance for vaccine development and possibly perinatal immunotherapy.