In-vitro production of HIV-specific antibody in children at risk of AIDS

Self-prescribed Ivermectin use is associated with a lower rate of seroconversion in health care workers diagnosed with COVID, in a dose-dependent response

Background

Over-the-counter use of ivermectin amongst other drugs as SARS-CoV-2 treatment has been increasingly common, despite the lack of evidence on its clinical efficacy.

Objective

To evaluate the effect of ivermectin use on production of antibodies against SARS-CoV-2 in health care workers (HCW) diagnosed with COVID-19 and of Th1/Th2 cytokines by stimulated peripheral blood mononuclear cells of the same cohort (PBMCs).

Methods

This cross-sectional study evaluated seroconversion and neutralizing antibodies production in HCW at Complexo Hospitalar Universitário Professor Edgard Santos (Salvador, Brazil), diagnosed with COVID-19 from May to July, 2020, as well as in vitro production of antibody against SARS-CoV-2 and Th1/Th2 cytokines. Analyses were performed between December 2020 and February 2021. Participants were stratified according to the use of ivermectin (≤ 1 dose vs. multiple doses) for treatment of COVID-19.

Results

45 HCW were included (62% women). Mean age was 39 years, and disease severity was similar across groups. Neutralizing antibodies were detected less frequently in multiple doses (70%) vs. ≤ 1 dose (97%) groups, p = 0.02). PBMCs of patients in multiple doses group also were less likely to produce antibodies against SARS-CoV-2 following in vitro stimulation with purified spike protein in comparison with patients in ≤ 1 dose group (p < 0.001). PBMC´s production of Th1/Th2 cytokines levels was similar across groups. Abdominal pain (15% vs 46%, p = 0.04), diarrhea (21% vs. 55%, p = 0.05) and taste perversion (0% vs. 18%, p = 0.05) were more frequently reported by participants that used multiple doses of ivermectin.

Conclusions

Although there was no evidence for differential disease severity upon ivermectin use for treatment of COVID-19 it was associated with more gastro-intestinal side-effects and impairment of anti-SARS-CoV2 antibodies production, in a dose dependent manner. This potentially impacts the effectiveness of immune response and the risk of reinfection and warrants additional studies for clarifying the mechanisms and consequences of such immunomodulatory effects.

THE VERTICAL TRANSMISSION OF HUMAN IMMUNODEFICIENCY VIRUS TYPE 1: Molecular and Biological Properties of the Virus

The vertical (mother-to-infant) transmission of human immunodeficiency virus type 1 (HIV-1 ) occurs at an estimated rate of more than 30% and is the major cause of AIDS in children. Numerous maternal parameters, including advanced dinical stages, low CD4+ lymphocte counts, high viral load, immune response, and disease progression have been implicated in an increased risk of vertical transmission. While the use of antiretroviral therapy (ART) during pregnancy has been shown to reduce the risk of vertical transmission, selective transmission of ART-resistant mutants has also been documented. Elucidation of the molecular mechanisms of vertical transmission might provide relevant information for the development of effective strategies for prevention and treatment. By using HIV-1 infected mother-infant pairs as a transmitter-recipient model, the minor genotypes of HIV-1 with macrophage-tropic and non-syncytium-inducing phenotypes (R5 viruses) in infected mothers were found to be transmitted to their infants and were initially maintained in the infants with the same properties. In addition, the transmission of major and multiple genotypes has been suggested. Furthermore, HIV-1 sequences found in non-transmitting mothers (mothers who failed to transmit HIV-1 to their infants in the absence of ART) were less heterogeneous than those from transmitting mothers, suggesting that viral heterogeneity may play an important role in vertical transmission. In the analysis of other regions of the HIV-1 genome, we have shown a high conservation of intact and functional gag p17, vif, vpr, vpu, tat, and nef open reading frames following mother-to-infant transmission. Moreover the accessory genes, vif and vpr, were less functionally conserved in the isolates of non-transmitting mothers than transmitting mothers and their infants. We, therefore, should target the properties of transmitted viruses to develop new and more effective strategies for the prevention and treatment of HIV-1 infection.

Paediatric HIV infection

By the year 2000 there will be six million pregnant women and five to ten million children infected with HIV-1. Intervention strategies have been planned and in some instances already started. A timely and cost-effective strategy needs to take into account that most HIV-1 infected individuals reside in developing countries. Further studies are needed on immunological and virological factors affecting HIV-1 transmission from mother to child, on differential disease progression in affected children, and on transient infection.

Maternal-Fetal Transmission of Human Immunodeficiency Virus

The World Health Organization estimates that by year 2000, 10 million children will be infected with human immunodeficiency virus type 1 (HIV-1) at birth and will subsequently develop AIDS. Perinatally acquired infections account for the majority of all HIV-1 cases in children, with an estimated mother-to-infant transmission rate of more than 30%. It is not clear why more than half of the children born to HIV-1-infected mothers are uninfected. Maternal transmission of HIV-1 occurs at three levels: prepartum, intrapartum, and postpartum. Several maternal parameters including advanced clinical stages of the mother, low CD4+ lymphocyte counts, maternal immune response to HIV-1, recent infection, high level of circulating HIV-1, and maternal disease progression have been implicated in an increased risk of mother-to-infant transmission of HIV-1. Viral factors influencing mother-to-infant transmission are not known. Furthermore, several other factors such as acute infection during pregnancy, presence of other sexually transmitted diseases (STD) or other chronic infections, vaginal bleeding, disruption of placental integrity, premature rupture of membrane (PROM), and preterm PROM have been associated with mother-to-infant transmission of HIV-1. In addition, tobacco and cigarette smoking during pregnancy have been shown to triple the rate of maternal transmission of HIV-1. The AIDS Clinical Trial Group (ACTG) suggested that zidovudine (ZDV) can reduce therate of mother-to-infant transmission of HIV-1 if administered to HIV-1-infected pregnant women with CD4 counts greater than 200. Moreover, this study failed to take into consideration several factors that may influence maternal transmission of HIV-1. However, the molecular mechanisms involved in mother-to-infant transmission of HIV-1 are not understood, which makes it more difficult to define strategies for effective treatment and prevention of HIV-1 infection in children. Several groups are engaged in the understanding of the molecular and biological properties of HIV-1 influencing mother-to-infant transmission. Results from my and several other laboratories suggest that the minor genotypes, subtypes, or variants of HIV-1 found in a genetically heterogeneous virus population of infected mothers are transmitted to their infants. The minor HIV-1 genotype predominates initially as a homogeneous population in the infant and then becomes diverse as the infant matures. Furthermore, transmission of a major or multiple HIV-1 genotypes from mother to infant has been reported. Taken together, these results strongly suggest that there are differences among the molecular and biological properties of the maternal variants that are transmitted to the infants and the maternal variants that are not transmitted to the infants. The understanding of the molecular and biological properties of the transmitted viruses will enable researchers to target a particular subtype in the mothers that is transmitted to the infants. Copyright 1996 S. Karger AG, Basel

Use of the in vitro induced antibody production test (IVIAP) to elucidate inconclusive status of HIV-1 infection

Studies have demonstrated the diagnostic usefulness of in vitro production of virus-specific antibodies by peripheral blood mononuclear cells (PMBC) from HIV-infected subjects. We evaluated the IVIAP (in vitro induced antibody production) by lympocytes from peripheral blood of 30 adult patients. Samples included 10 patients with inconclusive status of HIV-1 infection on previous serologic screening (2 blood donors, 8 with high risk behavior), 10 AIDS patients (CDC II-IV), and 10 known seronegative subjects. Positive IVIAP results were obtained on 2 of 10 inconclusive cases, earlier than seroconversion would demonstrate. The 8 remaining cases resulted in a negative outcome on IVIAP test, even in 2 seronegative homosexuals presenting Kaposi's sarcoma. Results showed 100% concordance either with a clinical/serological follow-up done after IVIAP tests or PCR performed for Kaposi's cases. Also, no false-positive or false-negative was detected on control groups. We concluded that IVIAP could identify the real status of HIV infection in a shorter time and with low cost compared to conventional serological methods currently available. The IVIAP test is easily performed so that can be considered as a routine supplemental test.

Prognostic value of immunological data, in vitro antibody production, and virus culture in vertical infection with HIV-1

The prognostic value of immunological indices, in vitro antibody production, and virus culture pattern at 3 months of age was estimated in 35 infants infected by HIV-1 from a cohort of 298 babies born to HIV-1 seropositive mothers and followed up from birth. At 1 year old, 15 of these infants were classified as stage P-1 (according to the Centers for Disease Control classification) seven were P-2A, and seven had AIDS. Significantly higher CD8 percentages, lower percentages and absolute value of CD4, and lower CD4/CD8 ratios at 3 months were observed in infants with severe symptoms at 1 year of age when compared with those who were asymptomatic at this age. Seventy seven per cent of infants with a 'rapid' virus culture when 3 months old had developed AIDS or had died by 1 year of age and only 8% of those with 'slow' virus culture had AIDS when 1 year old. Moreover, 100% of those who were asymptomatic at 1 year had a slow virus culture at 3 months. Significant statistical association was found between the virus replication pattern at 3 months and the clinical stage at 1 year of age.

Mother-to-child HIV-1 transmission: quantitative assessment of viral burden as a diagnostic tool and prognostic parameter in HIV-1-infected children

Polymerase chain reaction was performed in 251 infants born to HIV-1-seropositive mothers to diagnose HIV-1 infection. Assay specificity was invariably > 95%, regardless of age at testing, while sensitivity ranged from 15% in neonates (within 48 h of birth) to > 95% in infants over 1 month of age. Evaluation of viral burden in 43 infected infants by means of quantitative DNA-PCR disclosed that the number of HIV-1 proviruses ranged from 5 to 947 per 100,000 peripheral blood mononuclear cells. Clinical follow-up demonstrated that a high viral burden was associated significantly with disease onset.

Diagnosis and prediction of pediatric HIV-1 infection and AIDS: current status

The increase in the incidence of HIV-1 infection in women of child bearing age has resulted in a surge in the number of cases of pediatric AIDS. The World Health Organization (WHO) has estimated that the number of cases of pediatric AIDS worldwide will be at least 10 million by the year 2000. This alarming statistic underscores the need for accurate prediction and diagnosis of pediatric HIV-1 infection which is of paramount importance for the initiation of effective therapeutic interventions. Since circulating maternal anti-HIV-1 antibody persists in the baby for up to 21 months, early conventional serological diagnosis of infection is not possible. Other methods for diagnosis of HIV-1 infection in a child less than 2 years of age have been utilized including the polymerase chain reaction (PCR), measurements of the HIV-1 p24 core protein and anti-HIV-1 IgA, as well in vitro measurements of antibody producing cells. In addition, the ability to predict HIV-1 infection in the child based upon maternal humoral immune responses to the envelope glycoprotein has also been suggested. This review summarizes the recent serological, biological and molecular methodologies used to predict and diagnose pediatric HIV-1 infection and AIDS.

In vitro spontaneous production of anti-SIV antibodies is a reliable tool in the follow-up of protection of SIV-vaccinated monkeys

To assess the reliability of the spontaneous in vitro synthesis of simian immunodeficiency virus (SIV)-specific antibodies as a marker in the monitoring of protection in SIV-vaccinated animals, Macaca fascicularis monkeys were immunized with formalin-inactivated SIVmac251 or SIVmac251/32H, and challenged with human-derived (SIVmac251/32H) or monkey-derived live SIV. As judged by virus isolation and polymerase chain reaction (PCR) techniques, immunized animals were protected against human-derived SIV challenge, and no spontaneous in vitro synthesis of anti-SIV antibody was observed in nonstimulated peripheral blood mononuclear cell cultures over a 4-month follow-up. On the contrary, human cell-grown SIVmac251 immunization did not afford protection against monkey-derived SIV, and all the animals became infected and showed spontaneous in vitro synthesis of anti-SIV antibodies. These data demonstrate that lack of protection in SIV-vaccinated monkeys is strictly associated with PBMC ability of spontaneously produce anti-SIV antibodies in vitro following challenge, and suggest that this parameter might also constitute a reliable marker for monitoring protection in large-scale HIV vaccination and immunotherapy programs.

Dynamics of maternal IgG antibody decay and HIV-specific antibody synthesis in infants born to seropositive mothers. The NYC Perinatal HIV Transmission Study Group

We have used a human immunodeficiency virus type 1 (HIV-1)-specific IgG-Fc capture enzyme immunoassay (IgG-CEIA) to elucidate the dynamics of HIV-1 maternal antibody decay and de novo synthesis of HIV-1 antibodies in infants. Two hundred and thirty-nine serum specimens from 77 infants were analyzed by the IgG-CEIA and by two different conventional EIAs. With the IgG-CEIA, IgG was captured by an anti-human IgG monoclonal antibody (3C8) that reacts with all subclasses and was detected by recombinant HIV-1 envelope protein (CBre3)-peroxidase conjugate. Unlike the conventional EIAs, the IgG-CEIA showed a rapid decay of HIV-1-specific antibody in uninfected infants, with decline to background levels by 6 months (T1/2 [half-life] = 28-30 days). All 69 specimens collected from 39 uninfected infants between 6 and 15 months of age were negative by IgG-CEIA. However, HIV-1 antibodies remained high in infected infants; 20/22 infants (90.9%) with specimens between the ages of 6 to 23 months were positive by IgG-CEIA. Subtracting mean IgG-CEIA optical density values of seroreverting infants from those of HIV-1-infected infants in corresponding age groups provided a model for seroconversion in infected infants, with detectable IgG antibody synthesis starting about 3 months after birth. The IgG-CEIA may be a simple and important tool for early diagnosis of HIV-1 infection in infants at 6 months of age.

Virus isolation, polymerase chain reaction and in vitro antibody production for the diagnosis of pediatric human immunodeficiency virus infection

Viral culture (VC), polymerase chain reaction (PCR) and in vitro antibody production (IVAP) by peripheral blood mononuclear cells were compared for the early diagnosis of HIV-1 infection in 46 infants born to HIV-1 seropositive mothers. The ten children considered infected on the basis of clinical signs and persistence of anti-HIV-1 antibodies had at least one positive viral culture and seven were always positive in both PCR and IVAP tests. PCR and IVAP tests were occasionally negative in three infected children. Among 30 healthy children who became seronegative and were always negative for viral culture, 22 (73.3%) were also repeatedly negative in PCR and IVAP. We report 6 cases of children classified as P2A at the term of this study but who had lost anti-HIV-1 antibodies. They presented at least one positive viral culture and occasional positive PCR and/or IVAP results. The results indicate that the combination of viral culture, PCR and IVAP tests improves the early diagnosis of pediatric HIV infection.

Ontogeny of anti-human immunodeficiency virus (HIV) antibody production in HIV-1-infected infants

The early serologic response of infants to infection with human immunodeficiency virus type 1 (HIV-1) is normally obscured by the presence of transplacentally acquired maternal HIV antibody. By measuring HIV antibody produced in vitro by lymphocytes isolated from peripheral blood of infants and children of HIV-1-infected mothers, we have been able to study the natural acquisition of humoral immunity to perinatal HIV-1 infection. One hundred ninety-seven infants of HIV-1-infected women were studied prospectively and longitudinally from birth. In the neonatal period, infected infants produced only small amounts of HIV-specific IgG antibodies to a restricted number of antigens. The amount of immunoglobulin to HIV-1 and the number of HIV-1 antigens recognized increased with age. After 6 months of life 85% of infected infants made detectable antibody to two or more viral proteins. Antibody to gp160 appeared first and was the most frequently found at all ages, followed by antibody to the envelope proteins gp120 and gp41. The amount of HIV antibody produced correlated positively with the percentage of CD4+ T lymphocytes in peripheral blood. This assay provides a method of studying the immunogenicity of vaccines against HIV-1 in HIV-1-infected infants and of assessing the effect of early therapeutic interventions on the humoral response to HIV-1.

Human immunodeficiency virus infection in pregnancy

Human immunodeficiency virus (HIV) infection in women is an increasing problem. World wide, at least 25% of all infections occur in adolescent or adult women, most of whom are of child-bearing age. The commonest modes of acquisition of HIV infection are sexual contact with an HIV-infected male and sharing needles during injecting drug use. Vertical transmission is the major route of HIV infection in infants and children and can occur in utero, intrapartum, through exposure to infected blood or secretions, or post partum, via breast milk. HIV infection has not been demonstrated to affect fertility, or to influence the outcome of pregnancy unless there is evidence of significant immune dysfunction, with CD4 counts below 400/mm3. Though data are limited, pregnancy does not appear to affect the course of HIV infection. Low CD4 counts predispose women to the opportunistic infectious complications of HIV. Pathogens include Candida sp., Mycobacterium tuberculosis, Pneumocystis carinii, Toxoplasma gondii, Cryptococcus neoformans and Cryptosporidium. These pathogens require early recognition and diagnosis if optimal treatment and outcome are to be attained. Treatment with zidovudine and prophylaxis against Pneumocystis carinii are appropriate when CD4 counts are less than 200/mm3, though the safety of zidovudine in early pregnancy is not known. Similarly it is not known whether zidovudine treatment of the mother prevents transmission of HIV infection to her baby. Caesarean section does not prevent peripartum transmission of HIV and should be undertaken only for other appropriate indications. The utility of antenatal screening for HIV depends upon the seroprevalence in the population. Such programmes must be supported by comprehensive clinical care as well as sensitive and non-judgemental counselling.

Standardization of in vitro synthesis and detection of HIV-1-specific antibodies

Optimal conditions for in vitro anti-human immunodeficiency virus type 1 (HIV-1) antibody (Ab) synthesis and detection were re-appraised. Western blot (WB) and radioimmunoassay (RIA) could detect about 1 and 10 ng, respectively, of HIV-1-specific Ab (HIV-Ab), while the sensitivity of an enzyme-linked immunosorbent assay (ELISA) was much lower. Optimal HIV-Ab recovery was obtained by culturing 2.5 x 10(6) peripheral blood mononuclear cells (PBMC)/ml from seropositive subjects for 16 days in the absence of mitogens; at higher cell concentrations, background levels were unacceptably high. The background of non-de novo synthesized HIV-Ab was due to insufficient PBMC washing and/or cytophilic immunoglobulin (Ig); a particular washing procedure, as well as 24 h peripheral blood mononuclear cells (PBMC) pre-culture, might help in limiting this phenomenon. However, results should be compared with those obtained in cultures containing puromycin especially in infants, where a higher CD16 antigen expression in lymphocytes is likely responsible for increased amounts of cytophilic Ig released in culture supernatants, compared to adults.

The use of viral culture and p24 antigen testing to diagnose human immunodeficiency virus infection in neonates. The HIV Infection in Newborns French Collaborative Study Group

BACKGROUND

Early diagnosis of human immunodeficiency virus (HIV) infection in infants born to infected mothers is important for the infants' medical care, but the presence of maternal antibodies makes serologic tests uninformative.

METHODS

In a cohort study of 181 infants born to HIV-infected mothers, we assessed the diagnostic value of HIV viral culture and testing for the presence of p24 antigen. The infants were tested at birth, again during the first 3 months, then followed and tested at the age of at least 18 months.

RESULTS

Of the 181 infants, 3 died of HIV infection and 37 were seropositive after the age of 18 months. Viral cultures at birth were positive in 19 of the 40 infected infants and in none of the uninfected infants, yielding a sensitivity of 48 percent (95 percent confidence interval, 32 to 63 percent) and a specificity of 100 percent (95 percent confidence interval, 97 to 100 percent). By the age of three months, 30 of the 40 infants (75 percent) had positive cultures; again, there were no false positive results among the infants who were tested a second time, of the 141 who remained uninfected. The sensitivity of testing for p24 antigen at birth was only 18 percent, with a specificity of 100 percent. The presence of p24 antigen at birth was associated with the development of early and severe HIV-related disease (P less than 0.04).

CONCLUSIONS

Viral culture at birth can correctly identify about half of newborns with HIV infection. The fact that this usually sensitive technique fails to identify about half the ultimately infected neonates suggests that vertical transmission of HIV may occur late in pregnancy or during delivery.

AIDS: Part I

Acquired immunodeficiency syndrome (AIDS) is caused by infection with a pathogenic human retrovirus known as human immunodeficiency virus (HIV). Approximately 1 million people are currently infected with HIV in the United States, with 8 to 10 million infected individuals worldwide. The virus is transmitted predominantly through genital sexual contact, although orogenital spread has been rarely reported. Heterosexual transmission has been most common in the Third World, whereas male homosexual transmission has predominated in the United States and western Europe. Transmission through homosexual contact has been steadily declining over the past 5 years as transmission through illicit intravenous drug use and promiscuous unprotected heterosexual activity has increased. Sexually transmitted diseases that cause inflammatory or ulcerative lesions of the genital tract act as important cofactors in increasing the risk of transmission through sexual contact. Perinatal transmission of HIV occurs in approximately 30% of infants born to infected mothers. Transmission to infants through breast-feeding has also been documented. Health care workers have been infected with HIV through accidental high-risk percutaneous or mucous membrane exposures, albeit at a low transmission rate of 0.3%. Infection of patients by infected health care professionals is a rare event, having been reported only once in 10 years of the epidemic. Infection with HIV results in a chronic lifelong infection. The major targets for HIV are CD4+ T-helper lymphocytes and cells of monocyte/macrophage lineage. Infection of the T-helper lymphocyte ultimately results in the death of the cell. Over time (measured in years), a progressive destruction of the T-helper lymphocyte population occurs, which results in profound immune suppression. Infection of monocytes/macrophages is not cidal, but these cells do have functional alterations as a result of the infection, which may contribute to the immune deficiency. In addition, chronically infected tissue macrophages may act as an important reservoir for HIV, particularly in the central nervous system. Infection of the T-helper lymphocytes and monocytes/macrophages is mediated through attachment of HIV through a specific binding interaction between CD4 expressed in the plasma membrane of these cells and a surface glycoprotein on the virus, gp120. Once the virus nucleocapsid (core particle) enters the cytoplasm of the target cell, the viral RNA genome is reverse transcribed by a reverse transcriptase enzyme into proviral DNA. This proviral DNA migrates into the nucleus where it integrates into the host cellular genome, which results in a chronically infected cell.(ABSTRACT TRUNCATED AT 400 WORDS)

Secretion of Toxoplasma gondii-specific antibody in vitro by peripheral blood mononuclear cells as a new marker of acute toxoplasmosis

Antigen-specific antibody secretion in vitro by peripheral blood mononuclear cells (PBMC) reflects an in vivo stimulation of the immune system by the antigen. Primary infection of immunocompetent patients with T. gondii causes an acute infection followed by chronic toxoplasmosis. We examined in vitro anti-Toxoplasma antibody production by PBMC during the acute and chronic phases of toxoplasmosis. PBMC from patients with acute or chronic toxoplasmosis and seronegative subjects were cultured for up to 6 days. Anti-Toxoplasma antibodies were assayed in supernatants by ELISA and immunoblotting. Anti-Toxoplasma antibodies were detected in supernatants of PBMC from 29 pregnant women who seroconverted during gestation. PBMC from 17 patients who had chronic toxoplasmosis and PBMC from 10 seronegative healthy controls did not secrete Toxoplasma-specific antibodies. This in vitro antibody secretion was spontaneous, active and transient since it disappeared between 11 and 24 weeks after seroconversion. Anti-Toxoplasma antibody secretion by PBMC from patients with acute toxoplasmosis is consistent with an in vivo stimulation of the immune system by T. gondii antigens. Our results represent a new approach for studying the immunological response during T. gondii infection and could have important implications for the diagnosis of acute and re-activated toxoplasmosis.

Detection of IgA and IgM antibodies to HIV-1 in neonates by radioimmune western blotting

OBJECTIVE

To detect infection with HIV-1 by IgA and IgM response at birth in children born to HIV-1 seropositive mothers.

DESIGN

Western blotting and radioimmune western blotting on stored sera from infected and uninfected babies born to HIV-1 seropositive mothers. Sera were pretreated to remove IgG.

SETTING

Parma and Bologna, Italy.

SUBJECTS

12 infected and five uninfected babies born to HIV-1 seropositive mothers and three babies born to seronegative mothers.

MAIN OUTCOME MEASURES

Effectiveness of western blotting and radioimmune western blotting in detecting antibodies to HIV-1 gene products.

RESULTS

With conventional western blotting we found IgA class antibodies to HIV-1 proteins in serum from three out of 12 infected children; in two of these three the serum was collected at age 3 months (positive controls). Radioimmune western blotting detected both IgA and IgM antibodies in serum from all infected children tested, whereas all serum from uninfected children born to seropositive and seronegative mothers showed no such antibodies.

CONCLUSION

Although the technique should be tested on more patients, radioimmune western blotting seems to be a valuable tool for serological diagnosis of congenital HIV-1 infection at birth in neonates born to seropositive mothers.

Human immunodeficiency virus infection induces both polyclonal and virus-specific B cell activation

Peripheral blood lymphocytes (PBL) were obtained from HIV-1-infected patients at different stages of disease. The absolute number of IgM-, IgG-, and IgA-producing lymphocytes per 10(6) PBL was increased 2.8-, 3.4-, and 1.9-fold, respectively, compared with normal controls. 2-17% of IgG-secreting patient cells reacted with the gp160 envelope glycoprotein of HIV-1 (a 737-fold increase over background), while 1-9% reacted with p24 (140-fold over background). In addition to this HIV-specific B cell activation, the number of lymphocytes reactive with nonviral antigens such as DNA, myosin, actin, trinitrophenylated keyhole limpet hemocyanin, and ovalbumin was increased by a mean of 17.9-fold. Evidence suggests that the latter changes reflect an HIV-induced polyclonal B cell activation unrelated to the production of anti-HIV antibodies. For example, the proportion of IgG anti-gp160- and anti-p24-secreting lymphocytes declined in patients with advanced disease, whereas the number of B cells producing antibodies to non-HIV antigens rose. Moreover, CD4 cell count and T4/T8 ratio showed a significant inverse correlation with the degree of polyclonal activation but not with anti-HIV responsiveness. These observations demonstrate that both quantitative and qualitative changes in B cell activation accompany (and may be predictive of) disease progression in HIV-infected individuals.

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.

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.

Laboratory diagnosis of HIV infection

Laboratory diagnosis of human immunodeficiency virus (HIV) infection is complicated by absence of data on sensitivity, specificity and predictive value of the various tests as they apply to children. The presence of maternal anti-HIV passively transmitted across the placenta also confounds diagnosis. The authors review currently available data on the detection of HIV, HIV genome, and HIV gene products, as well as the diagnostic value of detecting serologic and cellular responses to HIV in infants and children.

Analysis of the spontaneous in vitro anti-HIV-1 antibody secretion by peripheral blood mononuclear cells in HIV-1 infection

We studied the spontaneous in vitro secretion of anti-HIV-1 antibodies by peripheral blood mononuclear cells (PBMC) from HIV-1-infected patients. Specific antibody production was detected in supernatants of PBMC cultures using an ELISA; HIV-1 specificity was confirmed by antigen adsorption and Western blotting. This antibody secretion was found to be an active phenomenon and was not due to a release of plasma antibodies passively adsorbed onto the cell membranes. In all positive supernatants, anti-HIV-1-secreted antibodies were directed against env-encoded antigens and many supernatants also contained antibodies to pol- and gag-encoded antigens. PBMC from all HIV-1-infected patients tested (140 adults and 18 infants) secreted anti-HIV-1 antibodies. This production was found during all the clinical stages of HIV-1 infection. Our results suggest that this spontaneous HIV-1-specific antibody secretion represents a marker of HIV-1 infection. Detection of these antibodies could be a valuable tool for early confirmation of HIV-1 infection in neonates born to HIV-1-seropositive mothers.

Unexplained CD4-positive T-cell deficiency in non-HIV patients presenting as a Pneumocystis carinii pneumonia

Three cases of Pneumocystis carinii pneumonia occurring in adults with unexplained T-cell defects are reported. No HIV markers were found during the follow up, and neither was any immunosuppressive disease. The authors emphasize the possibility that Pneumocystis pneumonia may occur and may be treated successfully in previously healthy subjects.

How frequent and how early does the neurological involvement in HIV-positive children occur? Preliminary results of a prospective study

To study the natural history of the neurological involvement in pediatric human immunodeficiency virus (HIV) infection, 77 children born to seropositive mothers have been followed up since birth. The median follow-up time has been 17.5 months. Fourteen children were classified as infected, 34 as not infected, and 21 as indeterminable. Only two children with full-blown acute immune deficiency syndrome had severe neurological manifestations. "Soft" neurological signs were found in six infected, and ten non-infected children (chi 2, P < 0.05). The mean development quotient and IQ scores in the infected and the non-infected children were 82.22, and 93.15, respectively (Mann-Whitney test, P > 0.05). These data suggest that neurological and developmental abnormalities do not occur early in the course of vertical HIV infection and that they are associated with severe immunodeficiency.

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.

Early diagnosis of HIV infection in infants by detection of IgA HIV antibodies

With the aim of achieving earlier diagnosis of human, immunodeficiency virus (HIV) infection in infants, IgA and IgM HIV antibodies in serum samples from babies born to seropositive mothers were assayed by immunoblot and enzyme-linked immunosorbent assay after removal of IgG with recombinant protein G. 64 samples were from 38 HIV-infected babies with Centers for Disease Control classifications of P1 or P2. Among these infected children IgA HIV antibodies were present in all 23 samples from those older than 12 months, in 12 of 18 samples from babies aged 6-12 months, in 5 of 10 samples from babies aged 3-5 months, and in 2 of 13 from babies under 3 months old. The 6 IgA-negative samples from infants over 6 months were all from infants with severe AIDS and/or hypogammaglobulinaemia. IgA HIV antibodies were present in twice as many samples as IgM HIV antibodies (66% vs 33%). No IgM or IgA HIV antibodies were detected in infants who subsequently seroreverted or in infants born to seronegative mothers. The correlation of the serological results with clinical information on each child suggests that detection of IgA HIV antibodies is an effective method for early diagnosis of HIV-infected infants without signs of infection.

Women and AIDS

This article describes the epidemiology of acquired immunodeficiency syndrome (AIDS) in women in the United States. Comparisons of female and male transmission categories are made and emphasis is placed on the heterosexual transmission and undetermined risk categories for women. Since its onset in 1981, AIDS has affected males predominantly and female AIDS cases have not received as much attention. AIDS education efforts have not targeted women as much as men, despite women's vulnerability to infection, especially through heterosexual transmission. AIDS tends to generate many issues that concern women's sexuality--contraception, pregnancy and abortion among them. Some of the special problems that women with AIDS face are discussed. Women's role as caregiver for persons with AIDS also is examined. Attention is directed to the ways in which AIDS is associated with the traditional female role.

ELISPOT: a new approach to studying the dynamics of virus-immune system interaction for diagnosis and monitoring of HIV infection

A new approach to detect and enumerate HIV-specific antibody-secreting cells (ASC) in the peripheral blood was developed using the enzyme-linked immunospot (ELISPOT) methodology. ASC to an HIV envelope recombinant protein were demonstrated in 75% of 16 adults and 72% of 21 children with untreated AIDS or ARC and in 63% of 34 asymptomatically infected adults but in none of the 51 HIV antibody-negative individuals. Only 1 of the 13 adults receiving AZT therapy yielded a positive reaction, and 27% of the 30 infants born to seropositive mothers were found to have HIV-ASC. The number of HIV-ASC in positive individuals varied from 8 to 202 per 10(6) circulating mononuclear cells. The reactivity was specifically inhibited by soluble HIV antigen and was abrogated by cycloheximide, indicating that the observed reaction was the result of de novo synthesis of HIV-specific antibodies. Nonspecific polyclonal B cell activation was unlikely to be responsible for the results observed as no reactivity was found to a common antigen, tetanus toxoid. Since circulating antigen-specific ASC reflect persistent or recent antigenic stimulation, our findings indicate that this new approach could provide a dynamic perspective of the natural course of virus-immune system interactions in individuals infected with HIV, as well as in those undergoing prophylactic or therapeutic interventions.

In vitro synthesis of human immunodeficiency virus-specific antibodies in peripheral blood lymphocytes of infants

An assay system was developed for the analysis of antibodies secreted in vitro against human immunodeficiency virus (HIV) by cultured peripheral blood lymphocytes of HIV-infected individuals. Cultures of peripheral blood lymphocytes were established with medium alone or with medium containing Epstein-Barr virus (EBV) or pokeweed mitogen. HIV antibodies were determined by an ELISA performed with commercial kits in which a whole virus extract served as antigen. Optimal antibody secretion was detected in 7-day peripheral blood lymphocyte cultures to which EBV had been added to provide polyclonal B-cell activation. Pokeweed mitogen-induced antibody secretion and spontaneous antibody secretion were less consistent. With EBV as a stimulus, the sensitivity and specificity of this assay for determining HIV infection status were each 100% in adults. When the assay was applied to infants and children, 23 of 24 symptomatic HIV-seropositive children (class P-2) and 11 of 33 asymptomatic seropositive infants aged less than or equal to 15 months (class P-0) tested positive for EBV-induced antibody secretion. Six of the 11 P-0 patients who tested positive have progressed to develop symptomatic disease, while the remainder are still seropositive at ages 2-15 months. Of the infants who were negative in this assay, all have remained asymptomatic. Treatment with 3'-azido-3'-deoxythymidine in infected adults and children has resulted in transient suppression of the in vitro antibody response in some instances. Thus EBV-induced synthesis of HIV-specific antibodies in vitro is a sensitive and specific indicator of HIV infection and is of help in determining infection status of asymptomatic seropositive infants who are classified as having "indeterminate" infection.

Vertical transmission of HIV: a prospective study

Forty nine infants of HIV seropositive women were followed up for a median of 24 months, together with 24 controls. The infection status of 11 index children under 18 months of age was indeterminate; 34 were presumed uninfected while four showed clinical and laboratory evidence of HIV disease. Based on current definitions of HIV infection and excluding children under 18 months old as well as those who had not been studied from birth, two out of 28 children were infected. The estimated rate of maternofetal transmission was therefore 7.1%. In children with proved infection, sequential laboratory data showed that hypergammaglobulinaemia was noted as early as 6 months and often predated clinical signs. This observation, in the presence of non-specific clinical findings, was helpful in alerting the paediatrician to a diagnosis of HIV infection.

Polymerase chain reaction compared with concurrent viral cultures for rapid identification of human immunodeficiency virus infection among high-risk infants and children

To determine the usefulness of DNA amplification by polymerase chain reaction for the early identification of human immunodeficiency virus type 1 (HIV-1) infection in infants and children, we compared the polymerase chain reaction and concurrent viral cultures of peripheral blood mononuclear cells from 25 high-risk subjects aged 5 weeks to 8 years. In two separate primer pairs, HIV-1 proviral DNA gag sequences were successfully identified in cell lysates from seven patients, including two infants with previously indeterminate HIV-1 status on the basis of serologic and culture results. In the remaining 18 patients the polymerase chain reaction was negative for HIV-1. Simultaneously grown HIV-1 cultures concurred with polymerase chain reaction results for all patients. In an 18-month-old infant who had had a single HIV-1 positive culture at 1 month of age with four subsequent negative cultures, both polymerase chain reaction and HIV-1 culture were negative. Our data demonstrate the clinical applicability of polymerase chain reaction on crude cell lysates for the rapid, early, definitive detection of HIV-1 infection in high-risk infants and children.

Antigen detection for human immunodeficiency virus

The recent development of enzyme immunoassay procedures for the direct determination of human immunodeficiency virus (HIV) antigens has been of significant benefit in both clinical and research applications. The historical development of HIV antigen assays as well as their current and future applications for use in the clinical microbiology laboratory are reviewed. A detailed description of selected commercially available assays is presented, and a comparison is made of various parameters, including sensitivity, specificity, and cost. The use of the HIV antigen assay as an alternative to the reverse transcriptase assay in virus culture applications is also discussed. In addition, the diagnostic and prognostic utility of the HIV antigen assay is considered for various patient groups, including neonatal, high-risk asymptomatic, seronegative, and seropositive patient populations. The use of the HIV antigen assay as an adjunct to anti-HIV antibody testing, as well as its utility in assessing the therapeutic efficacy of antiviral drug therapy, is discussed. The biology of HIV antigen expression and modulation of anti-HIV antibody titers during infection are also discussed in terms of two possible models.

Immunological evaluation in the early diagnosis of prenatal or perinatal HIV infection

A longitudinal evaluation was carried out of the clinical, infective, and immunological progress of 34 children (who were aged 6 to 68 months--mean 25 months at the time of writing) born to 31 mothers infected with human immunodeficiency virus (HIV), over a mean observation period of 13.4 months. Clinical symptoms, not always clearly related to HIV became apparent in 11 children, and preceding immune abnormalities were documented in two of them. In eight children culture for HIV was positive, and six of these were symptomatic. No cancers were diagnosed and none of the children died. Immune abnormalities including hypergammaglobulinaemia, IgG subclass deficiency, low serum IgA concentration, antibody deficiency, a decrease in the number of CD4+(T helper) cells, and defective cellular responses to antigens, were found in seven of the children in whom culture for HIV was positive; in two of four who had symptoms and in all four who were symptom free and in whom culture was negative for HIV but in whom HIV antibodies persisted and who were older than 15 months; and in three of nine who were symptom free and in whom culture was negative with loss of HIV antibodies. We conclude that serological diagnosis alone may be misleading and that additional immunological assessment may help to identify affected children. Analysis of humoral and cellular responses to antigens used for vaccination such as tetanus toxoid by measurement of specific antibodies and skin testing are simple and helpful in clinical practice.