Impaired haemophilus influenzae type b transplacental antibody transmission and declining antibody avidity through the first year of life represent potential vulnerabilities for HIV-exposed but -uninfected infants

The clinical epidemiology, management, and outcomes of patients diagnosed with encephalitis in North Carolina, 2015-2020

IMPORTANCE

Despite the relatively high mortality and the difficulty in diagnosis, nearly one-third of patients hospitalized with a documented diagnosis of encephalitis did not undergo a lumbar puncture (LP). When an LP was performed, pathogen-specific testing was greatly underutilized. Infectious etiologies were most common, but over 40% of cases were idiopathic at discharge. These findings suggest that there is a substantial opportunity to improve the quality of care through more accurate and timely diagnosis.

Effects of Maternal HIV Infection on Early Kaposi Sarcoma-Associated Herpesvirus Seroconversion in a Kenyan Mother-Infant Cohort

BACKGROUND

We identified whether maternal human immunodeficiency virus (HIV) infection during pregnancy affects transplacental transfer of Kaposi sarcoma-associated herpesvirus (KSHV)-specific antibodies and subsequent infant infection.

METHODS

We followed pregnant Kenyan women through delivery and their infants until age 2 years. Children were classified as HIV-exposed uninfected (HEU) or HIV-unexposed uninfected (HUU) based on maternal HIV status. Maternal venous and cord blood at delivery and child venous blood every 6 months were tested for antibodies to 20 KSHV antigens by multiplex bead-based immunoassay. Multiple comparisons were adjusted using false discovery rate (FDR).

RESULTS

Maternal HIV infection was significantly associated with decreased transplacental transfer of antibodies against all KSHV antigens and lower cord blood levels for 8 antigens at FDR P < .10. Neither birth to 6-month antibody level changes nor 6-month levels differed in HEU and HUU, except for ORF50. By age 24 months, 74% of children KSHV seroconverted but HEU and HUU did not differ in time to seroconversion nor 2-year seropositivity after adjustment for child malaria infection.

CONCLUSIONS

Maternal HIV infection reduced a child's initial KSHV antibody levels but did not affect age of infection. Regardless of HIV exposure in utero, KSHV seroconversion in Kenyan children occurred early; associated factors must be identified.

Crohn's patients and healthy infants share immunodominant B cell response to commensal flagellin peptide epitopes

About half of patients with Crohn's disease (CD) develop selective serum IgG response to flagellin proteins of the Lachnospiraceae family. Here, we identified a dominant B cell peptide epitope in CD, locating in the highly conserved "hinge region" between the D0 and D1 domains at the amino-terminus of Lachnospiraceae flagellins. Serum IgG reactive to this epitope is present at an elevated level in adult CD patients and in pediatric CD patients at diagnosis. Most importantly, high levels of serum IgG to the hinge epitope were found in most infants from 3 different geographic regions (Uganda, Sweden, and the USA) at one year of age. This vigorous homeostatic response decrements with age as it is not present in healthy adults. These data identify a distinct subset of CD patients, united by a shared reactivity to this dominant flagellin epitope that may represent failure of a homeostatic response beginning in infancy.

Defective Monocyte Enzymatic Function and an Inhibitory Immune Phenotype in Human Immunodeficiency Virus-Exposed Uninfected African Infants in the Era of Antiretroviral Therapy

BACKGROUND

Human immunodeficiency virus-exposed uninfected (HEU) infants are a rapidly expanding population in sub-Saharan Africa and are highly susceptible to encapsulated bacterial disease in the first year of life. The mechanism of this increased risk is still poorly understood. We investigated whether human immunodeficiency virus (HIV)-exposure dysregulates HEU immunity, vaccine-antibody production, and human herpes virus amplify this effect.

METHODS

Thirty-four HIV-infected and 44 HIV-uninfected pregnant women were recruited into the birth cohort and observed up to 6 weeks of age; and then a subsequent 43 HIV-infected and 61 HIV-uninfected mother-infant pairs were recruited into a longitudinal infant cohort at either: 5-7 to 14-15; or 14-15 to 18-23 weeks of age. We compared monocyte function, innate and adaptive immune cell phenotype, and vaccine-induced antibody responses between HEU and HIV-unexposed uninfected (HU) infants.

RESULTS

We demonstrate (1) altered monocyte phagosomal function and B-cell subset homeostasis and (2) lower vaccine-induced anti-Haemophilus influenzae type b (Hib) and anti-tetanus toxoid immunoglobulin G titers in HEU compared with HU infants. Human herpes virus infection was similar between HEU and HU infants.

CONCLUSIONS

In the era of antiretroviral therapy-mediated viral suppression, HIV exposure may dysregulate monocyte and B-cell function, during the vulnerable period of immune maturation. This may contribute to the high rates of invasive bacterial disease and pneumonia in HEU infants.

Immunoglobulin G passive transfer from mothers to infants: total IgG, IgG subclasses and specific antipneumococcal IgG in 6-week Malawian infants exposed or unexposed to HIV

Background

The impaired transplacental passage of IgG from mothers living with HIV to their infants could be one of the causes of the high vulnerability to infections of HIV-exposed uninfected (HEU) infants, but controversial results have been obtained in different settings. The aim of this study was to assess in 6-week old HEU and HIV-unexposed, uninfected (HUU) Malawian infants the total IgG levels, the subclasses profile and the concentrations of global anti-pneumococcal capsular polysaccharide (anti-PCP) IgG and IgG2.

Methods

Dried blood spots were collected from 80 infants (40 HEU, 40 HUU) and antibodies concentrations determined by nephelometric method (total IgG and subclasses), or using ELISA (anti-PCP total IgG and IgG2). Results are expressed as median levels with IQR, while the proportions of each subclass out of the total IgG are used to describe the subclasses profile.

Results

At 6 weeks HEU infants had higher median levels of total IgG and IgG1 and a significantly lower level of IgG2 [0.376 (0.344–0.523) g/l vs 0.485 (0.374–0.781) g/l, p = 0.037] compared to the HUU counterparts. The IgG subclasses distribution confirmed the underrepresentation of IgG2 (IgG2 represented 5.82% of total IgG in HEU and 8.87% in HUU). The anti-PCP IgG and IgG2 levels were significantly lower in HEU infants [8.9 (5.4–15.1) mg/l vs 16.2 (9.61–25.8) mg/l in HUU, p < 0.001, and 2.69 (1.90–4.29) mg/l vs 4.47 (2.96–5.71) mg/l in HUU, p = 0.001, respectively].

Conclusion

Compared to HUU infants, HEU infants have IgG abnormalities mainly represented by low IgG2 levels, suggesting that despite maternal antiretroviral therapy, the mechanisms of IgG transplacental passage continue to be impaired in women living with HIV. HEU infants also showed a significantly lower level of specific anti-PCP IgG, possibly favouring a high vulnerability to S. pneumoniae infection at an age when protection is mostly depending on maternal IgG.

Immunopathogenesis in HIV-associated pediatric tuberculosis

Tuberculosis (TB) is an increasing global emergency in human immunodeficiency virus/acquired immune deficiency syndrome (HIV/AIDS) patients, in which host immunity is dysregulated and compromised. However, the pathogenesis and efficacy of therapeutic strategies in HIV-associated TB in developing infants are essentially lacking. Bacillus Calmette-Guerin vaccine, an attenuated live strain of Mycobacterium bovis, is not adequately effective, which confers partial protection against Mycobacterium tuberculosis (Mtb) in infants when administered at birth. However, pediatric HIV infection is most devastating in the disease progression of TB. It remains challenging whether early antiretroviral therapy (ART) could maintain immune development and function, and restore Mtb-specific immune function in HIV-associated TB in children. A better understanding of the immunopathogenesis in HIV-associated pediatric Mtb infection is essential to provide more effective interventions, reducing the risk of morbidity and mortality in HIV-associated Mtb infection in infants. IMPACT: Children living with HIV are more likely prone to opportunistic infection, predisposing high risk of TB diseases. HIV and Mtb coinfection in infants may synergistically accelerate disease progression. Early ART may probably induce immune reconstitution inflammatory syndrome and TB pathology in HIV/Mtb coinfected infants.

Factors That Influence Infant Immunity and Vaccine Responses

The neonatal period and early infancy are times of increased vulnerability to infection. The immune system of infants undergoes rapid changes and a number of factors can influence the maturation and function of the early infant immune system, amongst these factors are maternal infections and immunity. Infants who are HIV-exposed, but uninfected show important immune alterations, which are likely to be associated with the increased morbidity and mortality observed in these infants. Maternally derived antibodies are crucial in early life to protect infants from infection during the time when their own immune system is becoming more experienced and fully mature. However, maternal antibodies can also interfere with the infant's own antibody responses to primary vaccination. Preterm infants are particularly vulnerable to infection, having not had the opportunity to benefit from the transplacental transfer of maternal antibodies in late pregnancy. In addition, further differences have been observed in the innate and adaptive immune system between preterm and term infants. Here, we focus on maternal influences on the infant immune system, using HIV and maternal vaccination as examples and finish by considering how prematurity impacts infant immune responses to vaccination.

Placental Transfer of Respiratory Syncytial Virus Antibody Among HIV-Exposed, Uninfected Infants

BACKGROUND

Maternal human immunodeficiency virus (HIV) infection is associated with lower placental transfer of antibodies specific to several childhood pathogens. Our objective for this study was to evaluate the effect of maternal HIV infection on the placental transfer of respiratory syncytial virus (RSV)-neutralizing antibodies.

METHODS

We conducted a cross-sectional study of mothers and their newborn infants at a tertiary hospital in Gaborone, Botswana, between March 2015 and December 2015. We measured serum RSV antibody levels by using a microneutralization assay. We used multivariable linear regression to evaluate the effect of maternal HIV infection on maternal RSV antibody levels, placental transfer of RSV antibodies, and newborn RSV antibody levels.

RESULTS

Of 316 mothers, 154 (49%) were infected with HIV. The placental transfer ratios for RSV antibodies to HIV-exposed, uninfected (HEU) and HIV-unexposed, uninfected infants were 1.02 and 1.15, respectively. The geometric mean titer (95% confidence interval) of RSV-neutralizing antibodies was 2657 (2251-3136) among HEU newborns and 2911 (2543-3331) among HIV-unexposed, uninfected newborns. In multivariable analyses, maternal HIV infection was associated with lower placental transfer of RSV antibodies (P = .02) and a lower level of RSV antibodies among newborns (P = .002). Among HEU newborns, higher birth weight (P = .004) and an undetectable maternal antenatal viral load (P = .01) were associated with more effective placental transfer of RSV antibodies.

CONCLUSIONS

Maternal human immunodeficiency virus (HIV) infection is associated with lower mother-to-fetus transfer of serum RSV-neutralizing antibodies. HEU infants should be prioritized for preventive interventions for RSV. Maternal viral suppression through combination antiretroviral therapy has the potential to improve immunity to RSV among HIV-exposed infants.

Extended Prophylaxis With Nevirapine Does Not Affect Growth in HIV-Exposed Infants

BACKGROUND

Effects of prolonged nevirapine prophylaxis exposure on growth among HIV-exposed uninfected (HEU) infants are unknown. This study examines the impact of extended nevirapine prophylaxis from 6 weeks to 6 months on the growth of HEU infants followed for 18 months and also identifies correlates of incident wasting, stunting, underweight, and low head circumference in the HPTN 046 trial.

METHODS

Intention-to-treat analysis examined the effect of extended nevirapine exposure on: weight-for-age Z-score, length-for-age Z-score, weight-for-length Z-score, and head circumference-for-age Z-score. Multivariable linear mixed-effects and Cox proportional hazard models were used to compare growth outcomes between the study arms and identify correlates of incident adverse growth outcomes, respectively.

RESULTS

Compared to placebo, extended prophylactic nevirapine given daily from 6 weeks to 6 months did not affect growth in HEU breastfeeding (BF) infants over time (treatment × time: P > 0.05). However, overall growth declined over time (time effect: P < 0.01) when compared with WHO general population norms. Male sex was associated with higher risk of all adverse growth outcomes (P < 0.05), whereas short BF duration was associated with wasting (P = 0.03). Maternal antiretroviral therapy exposure was protective against underweight (P = 0.02). Zimbabwe tended to have worse growth outcomes especially stunting, compared to South Africa, Uganda and Tanzania (P < 0.05).

CONCLUSIONS

It is reassuring that prolonged exposure to nevirapine for prevention-of-mother-to-child HIV transmission does not restrict growth. However, targeted interventions are needed to improve growth outcomes among at-risk HEU infants (i.e., male sex, short BF duration, lack of maternal antiretroviral therapy exposure, and resident in Zimbabwe).

Deficit of IgG2 in HIV-positive pregnant women is responsible of inadequate IgG2 levels in their HIV-uninfected children in Malawi

BACKGROUND

Transplacental passage of IgGs is impaired in HIV + pregnant women, possibly determining an inadequate immunological protection in their children. We aimed to determine the impact of maternal immunological IgG profile and immunoactivation status on the efficiency of transplacental passage of IgG subclasses in HIV + mothers.

METHODS

16 mother/infants pairs were studied in Malawi. Mothers received antiretroviral therapy (ART) from the third trimester of pregnancy. Determinations of pre-ART levels of maternal sCD14, of IgG subclasses in mothers at delivery and in their 1-month-old infants, were performed using commercial ELISA kits.

RESULTS

At delivery, after a median of 10 weeks of ART, 12/16 mothers were hypergammaglobulinemic, with IgG levels (20.5 mg/ml, 95% CI:18.8-26.8) directly correlated to the plasmatic levels of sCD14 (r = 0.640, p = 0.014). IgG1 levels (17.9 mg/ml) accounted for 82% of IgG, IgG3 and IgG4 levels were in the normal range. A profound deficit of IgG2 was observed both in mothers (0.60 mg/ml) and in infants (0.14 mg/ml). Placental transfer ratio (range 0.16-0.42) did not show a selective impairment between the different IgG subclasses. The transplacental passage of all IgG subclasses was decreased in the presence of maternal IgG over 16 mg/ml (significantly for IgG1, p = 0.031) and of high levels of sCD14 (p = 0.063).

CONCLUSIONS

Transplacental passage was reduced for all IgG subclasses and inversely correlated to high levels of maternal IgGs and to the degree of immunoactivation. The profound depression of IgG2 in mothers suggests that IgG2 neonatal levels mostly reflect the maternal deficit rather than a selective impairment of IgG2 transfer.

Immune responses to oral poliovirus vaccine in HIV-exposed uninfected Zimbabwean infants

It remains uncertain whether HIV-exposed uninfected (HEU) infants have impaired responses to oral vaccines. We performed a cross-sectional study of 6-month-old infants recruited at birth to the ZVITAMBO trial in Zimbabwe between 1997–2001, before introduction of prevention of mother-to-child transmission interventions. We measured poliovirus-specific IgA to type 1–3 polio strains by semi-quantitative capture ELISA in cryopreserved serum samples collected from 85 HEU and 101 HIV-unexposed infants at 6 months of age, one month after their last immunisation with trivalent OPV. Almost all infants were breastfed, with the majority in both groups mixed breastfed (70.6% HEU versus 71.3% HIV-unexposed). Median (IQR) vaccine titers for HEU and HIV-unexposed infants were 1592 (618–4896) vs. 1774 (711–5431) for Sabin 1 (P = 0.46); 1895 (810–4398) vs. 2308 (1081–4283) for Sabin 2 (P = 0.52); and 1798 (774–4192) vs. 2260 (996–5723) for Sabin 3 (P = 0.18). There were no significant differences in vaccine titers between HEU and HIV-unexposed infants, suggesting that vertical HIV exposure does not impact oral poliovirus vaccine immunogenicity.

Altered Natural Killer Cell Function in HIV-Exposed Uninfected Infants

Objectives

HIV-exposed uninfected (HEU) infants have higher rates of severe and fatal infections compared with HIV-unexposed (HUU) infants, likely due to immune perturbations. We hypothesized that alterations in natural killer (NK) cell activity might occur in HEU infants and predispose them to severe infections.

Design

Case–control study using cryopreserved peripheral blood mononuclear cells (PBMCs) at birth and 6 months from HEU infants enrolled from 2002 to 2009 and HUU infants enrolled from 2011 to 2013.

Methods

NK cell phenotype and function were assessed by flow cytometry after 20-h incubation with and without K562 cells.

Results

The proportion of NK cells among PBMCs was lower at birth in 12 HEU vs. 22 HUU (1.68 vs. 10.30%, p < 0.0001) and at 6 months in 52 HEU vs. 72 HUU (3.09 vs. 4.65%, p = 0.0005). At birth, HEU NK cells demonstrated increased killing of K562 target cells (p < 0.0001) and increased expression of CD107a (21.65 vs. 12.70%, p = 0.047), but these differences resolved by 6 months. Stimulated HEU NK cells produced less interferon (IFN)γ at birth (0.77 vs. 2.64%, p = 0.008) and at 6 months (4.12 vs. 8.39%, p = 0.001), and showed reduced perforin staining at 6 months (66.95 vs. 77.30%, p = 0.0008). Analysis of cell culture supernatants indicated that lower NK cell activity in HEU was associated with reduced interleukin (IL)-12, IL-15, and IL-18. Addition of recombinant human IL-12 to stimulated HEU PBMCs restored IFNγ production to that seen in stimulated HUU cultures.

Conclusion

NK cell proportion, phenotype, and function are altered in HEU infants. NK cell cytotoxicity and degranulation are increased in HEU at birth, but HEU NK cells have reduced IFNγ and perforin production, suggesting an adequate initial response, but decreased functional reserve. NK cell function improved with addition of exogenous IL-12, implicating impaired production of IL-12 by accessory cells. Alterations in NK cell and accessory cell function may contribute to the increased susceptibility to infection in HEU infants.

Contribution of Maternal Immunity to Decreased Rotavirus Vaccine Performance in Low- and Middle-Income Countries

The role of maternal immunity, received by infants either transplacentally or orally from breast milk, in rotavirus vaccine (RV) performance is evaluated here. Breastfeeding withholding has no effect on vaccine responses, but higher levels of transplacental rotavirus-specific IgG antibody contribute to reduced vaccine seroconversion. The gaps in knowledge on the factors associated with low RV efficacy in low- and middle-income countries (LMIC) remain, and further research is needed to shed more light on these issues.

The Immune System of HIV-Exposed Uninfected Infants

Infants born to human immunodeficiency virus (HIV) infected women are HIV-exposed but the majority remains uninfected [i.e., HIV-exposed uninfected (HEU)]. HEU infants suffer greater morbidity and mortality from infections compared to HIV-unexposed (HU) peers. The reason(s) for these worse outcomes are uncertain, but could be related to an altered immune system state. This review comprehensively summarizes the current literature investigating the adaptive and innate immune system of HEU infants. HEU infants have altered cell-mediated immunity, including impaired T-cell maturation with documented hypo- as well as hyper-responsiveness to T-cell activation. And although prevaccination vaccine-specific antibody levels are often lower in HEU than HU, most HEU infants mount adequate humoral immune response following primary vaccination with diphtheria toxoid, haemophilus influenzae type b, whole cell pertussis, measles, hepatitis B, tetanus toxoid, and pneumococcal conjugate vaccines. However, HEU infants are often found to have lower absolute neutrophil counts as compared to HU infants. On the other hand, an increase of innate immune cytokine production and expression of co-stimulatory markers has been noted in HEU infants, but this increase appears to be restricted to the first few weeks of life. The immune system of HEU children beyond infancy remains largely unexplored.

Transfer of Maternal Antimicrobial Immunity to HIV-Exposed Uninfected Newborns

The transfer of maternal immune factors to the newborn is critical for protection from infectious disease in early life. Maternally acquired passive immunity provides protection until the infant is beyond early life's increased susceptibility to severe infections or until active immunity is achieved following infant's primary immunization. However, as reviewed here, human immunodeficiency virus (HIV) infection alters the transfer of immune factors from HIV-infected mothers to the HIV-exposed newborns and young infants. This may relate to the immune activation in HIV-infected pregnant women, associated with the production of inflammatory cytokines at the maternofetal interface associated with inflammatory responses in the newborn. We also summarize mother-targeting interventions to improve the health of infants born to HIV-infected women, such as immunization during pregnancy and reduction of maternal inflammation. Maternal immunization offers the potential to compensate for the decreased transplacentally transferred maternal antibodies observed in HIV-exposed infants. Current data suggest reduced immunogenicity of vaccines in HIV-infected pregnant women, possibly reducing the protective impact of maternal immunization for HIV-exposed infants. Fortunately, levels of antibodies appear preserved in the breast milk of HIV-infected women, which supports the recommendation to breast-feed during antiretroviral treatment to protect HIV-exposed infants.

HIV-Exposed Uninfected Infants Show Robust Memory B-Cell Responses in Spite of a Delayed Accumulation of Memory B Cells: an Observational Study in the First 2 Years of Life

Improved HIV care has led to an increase in the number of HIV-exposed uninfected (HEU) infants born to HIV-infected women. Although they are uninfected, these infants experience increased morbidity and mortality. One explanation may be that their developing immune system is altered by HIV exposure, predisposing them to increased postnatal infections. We explored the impact of HIV exposure on the B-cell compartment by determining the B-cell subset distribution, the frequency of common vaccine antigen-specific memory B cells (MBCs), and the levels of antibodies to the respective antigens in HEU and HIV-unexposed uninfected (HUU) infants born to uninfected mothers, using flow cytometry, a B-cell enzyme-linked immunosorbent spot assay, and an enzyme-linked immunosorbent assay, respectively, during the first 2 years of life. For the majority of the B-cell subsets, there were no differences between HEU and HUU infants. However, HIV exposure was associated with a lower proportion of B cells in general and MBCs in particular, largely due to a lower proportion of unswitched memory B cells. This reduction was maintained even after correcting for age. These phenotypic differences in the MBC compartment did not affect the ability of HEU infants to generate recall responses to previously encountered antigens or reduce the antigen-specific antibody levels at 18 months of life. Although HIV exposure was associated with a transient reduction in the proportion of MBCs, we found that the ability of HEU infants to mount robust MBC and serological responses was unaffected.

HIV-Exposed Uninfected Infants in Zimbabwe: Insights into Health Outcomes in the Pre-Antiretroviral Therapy Era

The ZVITAMBO trial recruited 14,110 mother-infant pairs to a randomized controlled trial of vitamin A between 1997 and 2000, before the availability of antiretroviral therapy for HIV prophylaxis or treatment in Zimbabwe. The HIV status of mothers and infants was well characterized through 1-2 years of follow-up, leading to the largest cohort to date of HIV-exposed uninfected (HEU) infants (n = 3135), with a suitable comparison group of HIV-unexposed infants (n = 9510). Here, we draw on 10 years of published findings from the ZVITAMBO trial. HEU infants had increased morbidity compared to HIV-unexposed infants, with 50% more hospitalizations in the neonatal period and 30% more sick clinic visits during infancy, particularly for skin infections, lower respiratory tract infections, and oral thrush. HEU children had 3.9-fold and 2.0-fold higher mortality than HIV-unexposed children during the first and second years of life, respectively, most commonly due to acute respiratory infections, diarrhea/dysentery, malnutrition, sepsis, and meningitis. Infant morbidity and mortality were strongly related to maternal HIV disease severity, and increased morbidity remained until maternal CD4 counts were >800 cells/μL. HEU infants were more likely to be premature and small-for-gestational age than HIV-unexposed infants, and had more postnatal growth failure. Here, we propose a conceptual framework to explain the increased risk of infectious morbidity, mortality, and growth failure among HEU infants, hypothesizing that immune activation and inflammation are key drivers of both infection susceptibility and growth failure. Future studies should further dissect the causes of infection susceptibility and growth failure and determine the impact of ART and cotrimoxazole on outcomes of this vulnerable group of infants in the current era.

Maternal Human Immunodeficiency Virus-Associated Hypergammaglobulinemia Reduces Transplacental Transfer of Immunoglobulin G to Plasmodium falciparum Antigens in Cameroonian Neonates

Background. Human immunodeficiency virus (HIV) infection reduces placental transfer of antibodies from mother to the fetus for many antigens; however, conflicting data exist for transfer of immunoglobulin G (IgG) to malarial antigens. The mechanism(s) underlying reduced placental transfer is unknown.

Methods. Levels of maternal and cord total IgG, IgG subclasses, and cord-to-mother ratios (CMRs) were measured in 107 mother-cord pairs to 3 malarial antigens: circumsporozoite protein (CSP), apical membrane antigen 1 (AMA-1), merozoite surface protein 1 (MSP-1), and tetanus toxoid C-fragment (TTc).

Results. Immunoglobulin G levels to CSP and TTc were lower in HIV+ mothers, and cord IgG to CSP, MSP-1, and TTc were significantly lower in neonates born to HIV+ mothers (all P values <.05). The prevalence of mothers with hypergammaglobulinemia was significantly higher among HIV+ women (68%) compared with HIV− mothers (8%) (P < .0001). Maternal hypergammaglobulinemia was associated with reduction in transplacental transfer of antibodies to CSP (P = .03), MSP-1 (P = .004), and TTc (P = .012), and CMRs <1 were found for MSP-1 (odds ratio [OR] = 6.5), TTc (OR = 4.95), and IgG1 to CSP (OR = 3.75, P = .025) in statistical models adjusted for maternal IgG.

Conclusions. Data confirmed that HIV infections are associated with lower cord antibody levels to malarial antigens and that hypergammaglobulinemia may contribute to reduced antibody transfer.

HIV-exposed, uninfected infants: new global challenges in the era of paediatric HIV elimination

The number of infants infected with HIV is declining with the rise in interventions for the elimination of paediatric HIV infection, but the number of uninfected infants exposed to HIV through their HIV-infected mothers is increasing. Interest in the health outcomes of HIV-exposed, uninfected infants has grown in the past decade, with several studies suggesting that these infants have increased mortality rates, increased infectious morbidity, and impaired growth compared with HIV-unexposed infants. However, heterogeneous results might reflect the inherent challenges in studies of HIV-exposed, uninfected infants, which need large populations with appropriate, contemporaneous comparison groups and repeated HIV testing throughout the period of breastfeeding. We review the effects of HIV exposure on mortality, morbidity, and growth, discuss the immunological abnormalities identified so far, and provide an overview of interventions that could be effective in this susceptible population. As the number of infants infected with HIV declines, the health needs of HIV-exposed, uninfected infants should be prioritised further, to ensure that post-2015 Sustainable Development Goals are achieved.

Which New Health Technologies Do We Need to Achieve an End to HIV/AIDS?

In the last 15 years, antiretroviral therapy (ART) has been the most globally impactful life-saving development of medical research. Antiretrovirals (ARVs) are used with great success for both the treatment and prevention of HIV infection. Despite these remarkable advances, this epidemic grows relentlessly worldwide. Over 2.1 million new infections occur each year, two-thirds in women and 240,000 in children. The widespread elimination of HIV will require the development of new, more potent prevention tools. Such efforts are imperative on a global scale. However, it must also be recognised that true containment of the epidemic requires the development and widespread implementation of a scientific advancement that has eluded us to date--a highly effective vaccine. Striving for such medical advances is what is required to achieve the end of AIDS.

Antibodies against pneumococcal capsular polysaccharide in Malawian HIV-positive mothers and their HIV-exposed uninfected children

Background HIV-exposed uninfected children have a higher risk of infection and mortality compared to HIV-unexposed children and the reasons for this vulnerability are still under investigation.

AIM

This study aimed to evaluate the influence of maternal HIV parameters on the passive transfer of anti-pneumococcal capsular polysaccharide (PCP) IgG and to determine whether the concentrations of specific IgG might be related to the morbidity and mortality in HIV-exposed uninfected children. Methods One hundred and twenty-six Malawian HIV-infected pregnant women and their uninfected children were studied. Antiretroviral treatment-naive women started a nevirapine-based triple combination regimen from the third trimester of pregnancy until at least 6 months of exclusive breastfeeding. Mother/child pairs were followed until 2 years after delivery. Plasma anti-PCP IgG titers (in mothers at 26 weeks of gestation and in infants at 1 and 6 months) were determined by an enzyme-linked immunosorbent assay. None of these women and children had received any vaccination against pneumococcal polysaccharides. Results Maternal anti-PCP IgG concentration was independent from viral load (p = 0.848), CD4 count (p = 0.740) and WHO stage (p = 0.450). However, the child/mother ratio of anti-PCP IgG measured at 1 month among infants was significantly reduced in pairs whose mothers had HIV-RNA > 10 000 copies/ml (p = 0.043) and CD4 < 350 cells/μl (p = 0.090) before antiretroviral therapy (ART). No clear associations between anti-PCP IgG and respiratory-related deaths were found, but respiratory infection episodes were more frequent among children with lower anti-PCP IgG ratio (p = 0.046). Conclusion This study indicates that HIV pre-ART conditions in mothers may influence the rate of specific immunoglobulins transfer, increasing infants vulnerability to respiratory infections.