Immunoprophylaxis against mother-to-child transmission of HIV-1.
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ABSTRACT:
SUBMITTER: Gorny MK
PROVIDER: S-EPMC1513047 | biostudies-literature |
REPOSITORIES: biostudies-literature
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Project description:Hepatitis B virus (HBV) vaccination starting at birth is approximately 95% effective in preventing mother-to-child transmission to infants born to HBV-infected mothers. A higher risk of transmission is associated with birth to a highly viremic mother, often due to transplacental exposure, while later horizontal transmission is much less common, particularly following complete vaccination. This study reports a case of infection in an older child despite appropriate immunoprophylaxis starting at birth and an apparent protective immune response post-vaccination. Two immune escape mutations within the antigenic determinant of the surface antigen-coding region were observed in the child's dominant HBV sequence, whereas the maternal HBV variant lacked mutations at both sites. Ultra-deep sequencing confirmed the presence of 1 mutation at low levels within the maternal HBV quasispecies population, suggesting early exposure to the child followed by viral evolution resulting in immunoprophylaxis escape and chronic infection.
| S-EPMC6510327 | biostudies-literature
Project description:BACKGROUND:Vaccine escape mutants (VEMs) are one of the causes of breakthrough infections in the mother-to-child transmission of hepatitis B virus (HBV). We hypothesized that VEMs existing as minor populations in the maternal blood are associated with breakthrough infections in children. We sought to determine whether VEMs exist as minor populations in the preserved umbilical cords of children with breakthrough infections. CASE PRESENTATION:Two families (Family 1: three children, Family 2: two children) were enrolled. Despite immunoprophylaxis, a breakthrough infection occurred in two Family 1 children and two Family 2 children. Preserved umbilical cords, serum, and nails were used for the HBV DNA analysis. To detect VEMs, we performed direct and deep sequencing of hepatitis B surface antigen gene. The direct sequencing showed that there were no VEMs in the serum of the children or mother of Family 1 and family 2, but it identified a G145A mutant in the nails of the mother of Family 2. In Family 1, deep sequencing detected a T143S mutant as a minor population (1.7-2.0%) in the umbilical cords and serum of all three children and in the serum of the mother. A T126A mutant was also detected in the umbilical cord (9.2%) and serum (7.0%) of the first-born child of Family 1. In Family 2, the deep sequencing showed no VEMs in the umbilical cords, but it detected D144A (2.5%) and G145A (11.2%) mutants in the serum of the 2nd-born child. CONCLUSIONS:VEMs were present as minor populations in the preserved umbilical cords of children with breakthrough infections. The VEMs did not become major populations after the breakthrough infections. The evolution of VEMs from a minor form to a major form might not be a prerequisite for breakthrough infections in mother-to-child transmission.
| S-EPMC6873716 | biostudies-literature
Project description:This study examined HIV superinfection in HIV-infected women postpartum, and its association with mother-to-child transmission (MTCT).Plasma samples were obtained from HIV-infected women who transmitted HIV to their infants after 6 weeks of age (transmitters, n?=?91) and HIV-infected women who did not transmit HIV to their infants (nontransmitters, n?=?91). These women were originally enrolled in a randomized trial for prevention of MTCT of HIV in Malawi (Post-Exposure Prophylaxis of Infants trial in Malawi).Two HIV genomic regions (p24 and gp41) were analyzed by next-generation sequencing for HIV superinfection. HIV superinfection was established if the follow-up sample contained a new, phylogenetically distinct viral population. HIV superinfection and transmission risk were examined by multiple logistic regression, adjusted for Post-Exposure Prophylaxis of Infants study arm, baseline viral load, baseline CD4 cell count, time to resumption of sex, and breastfeeding duration.Transmitters had lower baseline CD4 cell counts (P?=?0.001) and higher viral loads (P?<?0.0001) compared with nontransmitters. There were five cases of superinfection among transmitters (rate of superinfection?=?4.7/100 person-years) compared with five cases among the nontransmitters (rate of superinfection?=?4.4/100 person-years; P?=?0.78). HIV superinfection was not associated with increased risk of postnatal MTCT of HIV after controlling for maternal age, baseline viral load, and CD4 cell count (adjusted odds ratio?=?2.32, P?=?0.30). Longer breastfeeding duration was independently associated with a lower risk of HIV superinfection after controlling for study arm and baseline viral load (P?=?0.05).There was a significant level of HIV superinfection in women postpartum, but this was not associated with an increased risk of MTCT via breastfeeding.
| S-EPMC4609898 | biostudies-literature
Project description:BackgroundStrategies to reduce the risk of mother-to-child transmission of the human immunodeficiency virus (HIV) include lifelong antiretroviral therapy (ART) for HIV-positive women, exclusive breastfeeding from birth for six weeks plus nevirapine or replacement feeding plus nevirapine from birth for four to six weeks, elective Caesarean section delivery, and avoiding giving children chewed food. In some settings, these interventions may not be practical, feasible, or affordable. Simple, inexpensive, and effective interventions (that could potentially be implemented even in the absence of prenatal HIV testing programmes) would be valuable. Vitamin A, which plays a role in immune function, is one low-cost intervention that has been suggested in such settings.ObjectivesTo summarize the effects of giving vitamin A supplements to HIV-positive women during pregnancy and after delivery.Search methodsWe searched the Cochrane Central Register of Controlled Trials (CENTRAL), PubMed, Embase, and the World Health Organization International Clinical Trials Registry Platform (WHO ICTRP) up to 25 August 2017, and checked the reference lists of relevant articles for eligible studies.Selection criteriaWe included randomized controlled trials conducted in any setting that compared vitamin A supplements to placebo or no intervention among HIV-positive women during pregnancy or after delivery, or both.Data collection and analysisAt least two review authors independently assessed study eligibility and extracted data. We expressed study results as risk ratios (RR) or mean differences (MD) as appropriate, with their 95% confidence intervals (CI), and conducted random-effects meta-analyses. This is an update of a review last published in 2011.Main resultsFive trials met the inclusion criteria. These were conducted in Malawi, South Africa, Tanzania, and Zimbabwe between 1995 and 2005 and none of the participants received ART. Women allocated to intervention arms received vitamin A supplements at a variety of doses (daily during pregnancy; a single dose immediately after delivery, or daily doses during pregnancy plus a single dose after delivery). Women allocated to comparison arms received identical placebo (6601 women, 4 trials) or no intervention (697 women, 1 trial). Four trials (with 6995 women) had low risk of bias and one trial (with 303 women) had high risk of attrition bias.The trials show that giving vitamin A supplements to HIV-positive women during pregnancy, the immediate postpartum period, or both, probably has little or no effect on mother-to-child transmission of HIV (RR 1.07, 95% CI 0.91 to 1.26; 4428 women, 5 trials, moderate certainty evidence) and may have little or no effect on child death by two years of age (RR 1.06, 95% CI 0.92 to 1.22; 3883 women, 3 trials, low certainty evidence). However, giving vitamin A supplements during pregnancy may increase the mean birthweight (MD 34.12 g, 95% CI -12.79 to 81.02; 2181 women, 3 trials, low certainty evidence) and probably reduces the incidence of low birthweight (RR 0.78, 95% CI 0.63 to 0.97; 1819 women, 3 trials, moderate certainty evidence); but we do not know whether vitamin A supplements affect the risk of preterm delivery (1577 women, 2 trials), stillbirth (2335 women, 3 trials), or maternal death (1267 women, 2 trials).Authors' conclusionsAntepartum or postpartum vitamin A supplementation, or both, probably has little or no effect on mother-to-child transmission of HIV in women living with HIV infection and not on antiretroviral drugs. The intervention has largely been superseded by ART which is widely available and effective in preventing vertical transmission.
| S-EPMC5618453 | biostudies-literature
Project description:BackgroundThe reproductive health and Prevention of Mother-to-Child Transmission (PMTCT) of HIV programs in Iran were integrated as a pilot project in September 2014. This study aims to provide a comprehensive evaluation and analysis of the PMTCT of HIV program in Iran.MethodsThe pilot phase of PMTCT of HIV was launched in early September 2014 in selected centers including 170 health centers and 40 hospitals affiliated to medical universities of 16 provinces of Iran. In each medical university, a researcher-made checklist was administered to all newly-diagnosed HIV-positive pregnant women by an AIDS expert. Data was analyzed using SPSS 19.ResultsOverall, 69.4% of eligible pregnant women were enrolled in the pilot phase. From 134 reactive cases, 76 (56.7%) were confirmed as HIV positive. ARV consumption was irregular in 10 (13.2%) of HIV positive pregnant women. Also, 82.5% had CD4 count more than 350 after treatment, with an average of 55.5% increase in the number of CD4 in comparison to the baseline, and 84.8% had viral load suppression (< 200 copies/ml). Counseling and testing was done for the husbands of 75% of the women that resulted in the identification of 15 (39.5%) new HIV cases among husbands. Among the tested individuals, 23 (60.5%) males already knew their HIV status and were registered as HIV patients. HIV was diagnosed in one (1.5%) newborn.ConclusionImplementation of rapid HIV testing and PMTCT in Iran is one of the strengths of the national HIV control program. To eliminate MTCT, it is necessary to understand and overcome the barriers and challenges to the program in the pilot phase.
| S-EPMC7948351 | biostudies-literature
Project description:The HIV-1 characteristics associated with mother to child transmission (MTCT) are still poorly understood and if known would indicate where intervention strategies should be targeted. In contrast to horizontally infected individuals, exposed infants possess inherited antibodies (Abs) from their mother with the potential to protect against infection. We investigated the HIV-1 gp160 envelope proteins from seven transmitting mothers (TM) whose children were infected either during gestation or soon after delivery and from four non-transmitting mothers (NTM) with similar viral loads and CD4 counts. Using pseudo-typed viruses we tested gp160 envelope glycoproteins for TZM-bl infectivity, CD4 and CCR5 interactions, DC-SIGN capture and transfer and neutralization with an array of common neutralizing Abs (NAbs) (2F5, 2G12, 4E10 and b12) as well as mother and infant plasma. We found no viral correlates associated with HIV-1 MTCT nor did we find differences in neutralization with the panel of NAbs. We did, however, find that TM possessed significantly higher plasma neutralization capacities than NTM (P?=?0.002). Furthermore, we found that in utero (IU) TM had a higher neutralization capacity than mothers transmitting either peri - partum (PP) or via breastfeeding (BF) (P?=?0.002). Plasma from children infected IU neutralized viruses carrying autologous gp160 viral envelopes as well as those from their corresponding mothers whilst plasma from children infected PP and/or BF demonstrated poor neutralizing capacity. Our results demonstrate heightened autologous NAb responses against gp120/gp41 can associate with a greater risk of HIV-1 MTCT and more specifically in those infants infected IU. Although the number of HIV-1 transmitting pairs is low our results indicate that autologous NAb responses in mothers and infants do not protect against MTCT and may in fact be detrimental when considering IU HIV-1 transmissions.
| S-EPMC3714266 | biostudies-literature
Project description:Introduction: Human Beta Defensin-1 (hBD-1) is a component of the innate immune system, the first line of defence against pathogens, already reported as involved in the susceptibility to HIV-1 infection and HIV-1 mother-to-child transmission (MTCT) in different populations. We investigated the role of DEFB1 gene (encoding for hBD-1) functional polymorphisms in the susceptibility to HIV-1 MTCT in a population from Zambia. Methods: Four selected polymorphisms within DEFB1 gene, three at the 5' untranslated region (UTR), namely -52G?>?A (rs1799946), -44C?>?G (rs1800972) and -20G?>?A (rs11362) and one in the 3'UTR, c.*87A?>?G (rs1800972), were genotyped in 101 HIV-1 positive mothers (26 transmitters -27% and 75 not transmitters -73%) and 331 infants born to HIV-1 infected mothers (85 HIV-1 positive -26% and 246 exposed but not infected -74%). Results: DEFB1 c.*87-A allele was more frequent among HIV- children with respect to HIV+ (with intrauterine MTCT). Concerning DEFB1 haplotypes, GCGA haplotype resulted more represented in HIV- than HIV+ infants and DEFB1 ACGG haplotype presented increased frequency in HIV- children respect to HIV+ (with intra-partum MTCT) (p?=?.02, p?=?.002 and p?=?.006, respectively). Conclusions: DEFB1 polymorphisms were significantly associated with decreased risk of HIV-1 infection acquisition in the studied Zambian population suggesting that they may play a role in HIV-1 MTCT.
| S-EPMC6202264 | biostudies-literature
Project description:Mother-to-child HIV-1 transmission pairs represent a good opportunity to study the dynamics of CTL escape and reversion after transmission in the light of shared and non-shared HLA-alleles. Mothers share half of their HLA alleles with their children, while the other half is inherited from the father and is generally discordant between mother and child. This implies that HIV-1 transmitted from mother to child enters a host environment to which it has already partially adapted. Here, we studied viral evolution and the dynamics of CTL escape mutations and reversion of these mutations after transmission in the context of shared and non-shared HLA alleles in viral variants obtained from five mother-to-child transmission pairs. Only limited HIV-1 evolution was observed in the children after mother-to-child transmission. Viral evolution was mainly driven by forward mutations located inside CTL epitopes restricted by HLA alleles inherited from the father, which may be indicative of CTL pressure.
| S-EPMC5381489 | biostudies-literature
Project description:Exposure of the infant's gut to cell-associated and cell-free HIV-1 trafficking in breast milk (BM) remains a primary cause of mother-to-child transmission (MTCT). The mammary gland represents a unique environment for HIV-1 replication and host-virus interplay. We aimed to explore the origin of the virus transmitted during breastfeeding, and the link with quasi-species found in acellular and cellular fractions of breast-milk (BM) and in maternal plasma. The C2-V5 region of the env gene was amplified, cloned and sequenced from the RNA and DNA of BM, the RNA from the mother's plasma (PLA) and the DNA from infant's dried blood spot (DBS) in 11 post-natal mother-infant pairs. Sequences were assembled in Geneious, aligned in ClustalX, manually edited in SeAL and phylogenetic reconstruction was undertaken in PhyML and MrBayes. We estimated the timing of transmission (ETT) and reconstructed the time for the most recent common ancestor (TMRCA) of the infant in BEAST. Transmission of single quasi-species was observed in 9 of 11 cases. Phylogenetic analysis illustrated a BM transmission event by cell-free virus in 4 cases, and by cell-associated virus in 2 cases but could not be identified in the remaining 5 cases. Molecular clock estimates, of the infant ETT and TMRCA, corresponded well with the timing of transmission estimated by sequential infant DNA PCR in 10 of 11 children. The TMRCA of BM variants were estimated to emerge during gestation in 8 cases. We hypothesize that in the remaining cases, the breast was seeded with a long-lived lineage latently infecting resting T-cells. Our analysis illustrated the role of DNA and RNA virus in MTCT. We postulate that DNA archived viruses stem from latently infected quiescent T-cells within breast tissue and MTCT can be expected to continue, albeit at low levels, should interventions not effectively target these cells.
| S-EPMC4368793 | biostudies-literature
Project description:The jury on transmission of HIV through breast-feeding is still on. Data from a clinical trial in children born to HIV-positive mothers were evaluated with respect to their relationship to mother-to-child transmission. A total of 1629 infants who were not infected at age 6 weeks, had HIV results available at 12 months and who were breast-fed were included in this study. Exclusive breast feeding (EBF) rates declined from 85% at 2 months to?<?30% by 4 months. EBF was associated with a sustained and significant reduction in HIV infection. With every incremental month of EBF, HIV infection was reduced by 16% [multivariable (risk ratio) RR: 0.84, CI: 0.72-0.98, p = 0.03] from enrollment to 6 months of age and by 18% (multivariable RR: 0.82, CI: 0.72-0.94, p = 0.005) from enrollment to 12 months of age. EBF significantly reduces the risk of vertical HIV transmission through 12 months of age.
| S-EPMC6089093 | biostudies-literature