1,164 research outputs found
Premature aging and immune senescence in HIV-infected children
Objective: Several pieces of evidence indicate that HIV-infected adults undergo premature aging. The effect of HIV and antiretroviral therapy (ART) exposure on the aging process of HIV-infected children may be more deleterious since their immune system coevolves from birth with HIV.
Design: Seventy-one HIV-infected (HIV+), 65 HIV-exposed-uninfected (HEU), and 56 HIV-unexposed-uninfected (HUU) children, all aged 0\u20135 years, were studied for biological aging and immune senescence.
Methods: Telomere length and T-cell receptor rearrangement excision circle levels were quantified in peripheral blood cells by real-time PCR. CD4+ and CD8+ cells were analysed for differentiation, senescence, and activation/exhaustion markers by flow cytometry.
Results: Telomere lengths were significantly shorter in HIV+ than in HEU and HUU children (overall, P < 0.001 adjusted for age); HIV+ ART-naive (42%) children had shorter telomere length compared with children on ART (P = 0.003 adjusted for age). T-cell receptor rearrangement excision circle levels and CD8+ recent thymic emigrant cells (CD45RA+CD31+) were significantly lower in the HIV+ than in control groups (overall, P = 0.025 and P = 0.005, respectively). Percentages of senescent (CD28-CD57+), activated (CD38+HLA-DR+), and exhausted (PD1+) CD8+ cells were significantly higher in HIV+ than in HEU and HUU children (P = 0.004, P < 0.001, and P < 0.001, respectively). Within the CD4+ cell subset, the percentage of senescent cells did not differ between HIV+ and controls, but programmed cell death receptor-1 expression was upregulated in the former.
Conclusions: HIV-infected children exhibit premature biological aging with accelerated immune senescence, which particularly affects the CD8+ cell subset. HIV infection per se seems to influence the aging process, rather than exposure to ART for prophylaxis or treatmen
Vertical transmission of zika virus and its outcomes:a Bayesian synthesis of prospective studies
BACKGROUND: Prospective studies of Zika virus in pregnancy have reported rates of congenital Zika syndrome and other adverse outcomes by trimester. However, Zika virus can infect and damage the fetus early in utero, but clear before delivery. The true vertical transmission rate is therefore unknown. We aimed to provide the first estimates of underlying vertical transmission rates and adverse outcomes due to congenital infection with Zika virus by trimester of exposure.METHODS: This was a Bayesian latent class analysis of data from seven prospective studies of Zika virus in pregnancy. We estimated vertical transmission rates, rates of Zika-virus-related and non-Zika-virus-related adverse outcomes, and the diagnostic sensitivity of markers of congenital infection. We allowed for variation between studies in these parameters and used information from women in comparison groups with no PCR-confirmed infection, where available.FINDINGS: The estimated mean risk of vertical transmission was 47% (95% credible interval 26 to 76) following maternal infection in the first trimester, 28% (15 to 46) in the second, and 25% (13 to 47) in the third. 9% (4 to 17) of deliveries following infections in the first trimester had symptoms consistent with congenital Zika syndrome, 3% (1 to 7) in the second, and 1% (0 to 3) in the third. We estimated that in infections during the first, second, and third trimester, respectively, 13% (2 to 27), 3% (-5 to 14), and 0% (-7 to 11) of pregnancies had adverse outcomes attributable to Zika virus infection. Diagnostic sensitivity of markers of congenital infection was lowest in the first trimester (42% [18 to 72]), but increased to 85% (51 to 99) in trimester two, and 80% (42 to 99) in trimester three. There was substantial between-study variation in the risks of vertical transmission and congenital Zika syndrome.INTERPRETATION: This preliminary analysis recovers the causal effects of Zika virus from disparate study designs. Higher transmission in the first trimester is unusual with congenital infections but accords with laboratory evidence of decreasing susceptibility of placental cells to infection during pregnancy.FUNDING: European Union Horizon 2020 programme
Researching Zika in pregnancy:lessons for global preparedness
Our understanding of congenital infections is based on prospective studies of women infected during pregnancy. The EU has funded three consortia to study Zika virus, each including a prospective study of pregnant women. Another multi-centre study has been funded by the US National Institutes of Health. This Personal View describes the study designs required to research Zika virus, and questions whether funding academics in the EU and USA to work with collaborators in outbreak areas is an effective strategy. 3 years after the 2015\u201316 Zika virus outbreaks, these collaborations have taught us little about vertical transmission of the virus. In the time taken to approve funding, agree contracts, secure ethics approval, and equip laboratories, Zika virus had largely disappeared. By contrast, prospective studies based on local surveillance and standard-of-care protocols have already provided valuable data. Threats to fetal and child health pose new challenges for global preparedness requiring support for the design and implementation of locally appropriate protocols. These protocols can answer the key questions earlier than externally designed studies and at lower cost. Local protocols can also provide a framework for recruitment of unexposed controls that are required to study less specific outcomes. Other priorities include accelerated development of non-invasive tests, and longer-term storage of neonatal and antenatal samples to facilitate retrospective reconstruction of cohort studies
Early and Highly Suppressive ART are Main Factors Associated with Low Viral Reservoir in European Perinatally HIV Infected Children
Abstract
BACKGROUND:
Future strategies aiming to achieve HIV-1 remission are likely to target individuals with small reservoir size.
SETTING:
We retrospectively investigated factors associated with HIV-1 DNA levels in European, perinatally HIV-infected children starting ART <6 months of age.
METHODS:
Total HIV-1 DNA was measured from 51 long-term suppressed children 6.3 years (median) after initial viral suppression. Factors associated with log10 total HIV-1 DNA were analyzed using linear regression.
RESULTS:
At ART initiation, children were aged median [IQR] 2.3 [1.2,4.1] months, CD4% 37 [24,45] %, CD8% 28 [18,36] %, log10 plasma viral load (VL) 5.4 [4.4,5.9] copies/ml. Time to viral suppression was 7.98 [4.6,19.3] months. Following suppression, 13 (25%) children had suboptimal response [ 652 consecutive VL50-400 followed by VL<50] and/or experienced periods of virological failure [ 652 consecutive VL 65400 followed by VL<50]. Median total HIV-1 DNA was 43 [6,195] copies/10 PBMC.Younger age at therapy initiation was associated with lower total HIV-1 DNA (adjusted coefficient [AC] 0.12 per month older, p=0.0091), with a month increase in age at ART start being associated with a 13% increase in HIV DNA. Similarly, a higher proportion of time spent virally suppressed (AC 0.10 per 10% higher, p=0.0022) and absence of viral failure/suboptimal response (AC 0.34 for those with fail/ suboptimal response, p=0.0483) were associated with lower total HIV-1 DNA.
CONCLUSION:
Early ART initiation and a higher proportion of time suppressed are linked with lower total HIV-1 DNA. Early ART start and improving adherence in perinatally HIV-1 infected children minimize the size of viral reservoir.This is an open-access article distributed under the terms of the Creative Commons Attribution-Non Commercial License 4.0 (CCBY-NC), where it is permissible to download, share, remix, transform, and buildup the work provided it is properly cited. The work cannot be used commercially without permission from the journal
Premature aging and immune senescence in HIV-infected children.
Objective: Several pieces of evidence indicate that HIV-infected adults undergo premature aging. The effect of HIV and antiretroviral therapy (ART) exposure on the aging process of HIV-infected children may be more deleterious since their immune system coevolves from birth with HIV. Design: Seventy-one HIV-infected (HIV+), 65 HIV-exposed-uninfected (HEU), and 56 HIV-unexposed-uninfected (HUU) children, all aged 0-5 years, were studied for biological aging and immune senescence. Methods: Telomere length and T-cell receptor rearrangement excision circle levels were quantified in peripheral blood cells by real-time PCR. CD4+ and CD8+ cells were analysed for differentiation, senescence, and activation/exhaustion markers by flow cytometry. Results: Telomere lengths were significantly shorter in HIV+ than in HEU and HUU children (overall, Pâ<â0.001 adjusted for age); HIV+ ART-naive (42%) children had shorter telomere length compared with children on ART (Pâ=â0.003 adjusted for age). T-cell receptor rearrangement excision circle levels and CD8+ recent thymic emigrant cells (CD45RA+CD31+) were significantly lower in the HIV+ than in control groups (overall, Pâ=â0.025 and Pâ=â0.005, respectively). Percentages of senescent (CD28âCD57+), activated (CD38+HLA-DR+), and exhausted (PD1+) CD8+ cells were significantly higher in HIV+ than in HEU and HUU children (Pâ=â0.004, Pâ<â0.001, and Pâ<â0.001, respectively). Within the CD4+ cell subset, the percentage of senescent cells did not differ between HIV+ and controls, but programmed cell death receptor-1 expression was upregulated in the former. Conclusions: HIV-infected children exhibit premature biological aging with accelerated immune senescence, which particularly affects the CD8+ cell subset. HIV infection per se seems to influence the aging process, rather than exposure to ART for prophylaxis or treatment. Keywords: immune activation, immune senescence, microbial translocation, pediatric HIV/AIDS, premature aging, telomere length, T-cell receptor rearrangement excision circl
Biological Activities of Essential Oils: From Plant Chemoecology to Traditional Healing Systems
Essential oils are complex mixtures of hydrocarbons and their oxygenated derivatives arising from two different isoprenoid pathways. Essential oils are produced by glandular trichomes and other secretory structures, specialized secretory tissues mainly diffused onto the surface of plant organs, particularly flowers and leaves, thus exerting a pivotal ecological role in plant. In addition, essential oils have been used, since ancient times, in many different traditional healing systems all over the world, because of their biological activities. Many preclinical studies have documented antimicrobial, antioxidant, anti-inflammatory and anticancer activities of essential oils in a number of cell and animal models, also elucidating their mechanism of action and pharmacological targets, though the paucity of in human studies limits the potential of essential oils as effective and safe phytotherapeutic agents. More well-designed clinical trials are needed in order to ascertain the real efficacy and safety of these plant products
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