Delayed seroreversion of specifical antibody against HIV in HIV-exposed infants: A retrospective cohort study

OBJECTIVES

To investigate the seroreversion time in HIV-1-exposed but uninfected infants from two tertiary hospitals in China.

METHODS

This study retrospectively investigated the data of perinatal, HIV-1-exposed infants from hospitals in Beijing and Shenzhen. Maternal and infant medical records from both hospitals from January 2009 to December 2019 were reviewed, and the HIV antibody seroreversion times of infants were determined. From 2009 to 2019, a total of 485 HIV-1-exposed but uninfected infants were enrolled. The majority of infants were born at term with normal birth weight.

RESULTS

The seroreversion rates were 89.3%, 94.2% and 100% at 12, 18 and 24 months of age, respectively. There were no significant associations between seroreversion and several risk factors, such as gender, birth weight, gestational age, mode of delivery, postpartum prophylaxis and antiretroviral treatment duration. The mean value of HIV-specific immunoglobulin G concentration decreased from 15.4 at day 42 to 0.03 after 24 months in HIV-exposed, uninfected infants.

CONCLUSIONS

Clearance of HIV antibodies could take more than 18 months in a small number of perinatally exposed infants. Caution should be used in excluding or diagnosing perinatal HIV infection in children with long persistence of HIV antibodies.

Diffusion-tensor imaging for differentiating uterine sarcoma from degenerative uterine fibroids

AIM

To explore the applicability of diffusion-tensor imaging (DTI) sequence quantitative parameters in differentiating uterine sarcoma (USr) from degenerative uterine fibroids (DUF).

MATERIALS AND METHODS

Fourteen cases of USr and 30 cases of DUF were analysed retrospectively. The diffusion-weighted imaging (DWI) and DTI images were analysed by two observers using Functool software on a ADW4.6 workstation. The images were post-processed to generate an apparent diffusion coefficient (ADC) map of DWI, ADC map of DTI (ADC^T map), and fractional anisotropy (FA) map. Three regions of interest (ROI) were selected from the ADC, ADC^T, and FA maps to obtain the ADC, ADC^T, and FA values. The receiver operating characteristic (ROC) curves of all parameters were used to analyse and compare the diagnostic value of USr and DUF.

RESULTS

The ADC value, ADC^T value, and FA value of USr (1.190 ± 0.262 × 10^-3mm²/s, 1.165 ± 0.270 × 10^-9mm²/s, 0.168 ± 0.063) were significantly lower compared to the values for DUF (1.525 ± 0.314 × 10^-3mm²/s, 1.650 ± 0.332 × 10^-9mm²/s, 0.254 ± 0.111; all p<0.001). The diagnostic threshold values for USr were: ADC ≤1.290 × 10^-3mm²/s, ADC^T ≤1.322 × 10^-9mm²/s and FA ≤0.192. The corresponding sensitivities and specificities were 78.6%/90%, 96.7%/92.9%, and 86.7%/85.7%, respectively. The areas under the curve (AUC) were 0.875, 0.974, and 0.831, respectively.

CONCLUSIONS

DTI quantitative parameters can be used to differentiate USr from DUF. The ADC^T value had the highest diagnostic efficacy.

PCSK9 is associated with disease activity and implicated in immune activation and cardiovascular disease in Systemic Lupus Erythematosus

Background

The risk of atherosclerosis and cardiovascular disease (CVD) is very high in SLE. This is both a clinical problem and of interest in studies of immunity in these conditions. LDL-levels are increased by Proprotein convertase subtilisin kexin 9 (PCSK9) which targets the LDL-receptor (LDLR). We recently reported that PCSK9 ameliorates dendritic cell (DC) activation by oxidized LDL (OxLDL), which is abundant in atherosclerotic plaques and also raised and associated with cardiovascular disease (CVD) in SLE. We here investigate the role of PCSK9 in SLE.

Methods

PCSK9-levels were determined by ELISA among SLE patients (n=109) and age- and sex-matched population-based controls (n=91). Common carotid intima-media thickness (IMT) and plaque occurrence were determined by B-mode ultrasound. Plaques were graded by echogenicity. Human peripheral blood monocytes from SLE patients or controls were differentiated into DCs. Effects of PCSK9 and its inhibition by silencing were studied.

Results

PCSK9-levels were non-significantly higher among SLE-patients as compared to controls but associated significantly with SLE disease activity, as determined by SLAM (0.020) or SLEDAI (0.0178). There was no association between PCSK9-levels and atherosclerosis as determined by IMT, prevalence of plaques or echolucent (potentially vulnerable) plaques. PCSK9 levels were significantly associated with CVD among SLE-patients.

OxLDL induced PCSK9 in DCs and DC-maturation with increased expression of CD86 and HLA-DR. The effects were significantly stronger in DC from SLE patients than from controls. Silencing of PCSK9 abolished OxLDL-induced DC-maturation.

Conclusions

PCSK9 is associated with disease activity in SLE. One underlying cause could be OxLDL, promoting DC-activation which depends on PCSK9. OxLDL induces PCSK9, an effect which is higher among SLE-patients. PCSK9 could play an unexpected immunological role in SLE.

Funding Acknowledgement

Type of funding source: Private company. Main funding source(s): Amgen; Swedish Heart and Lung Foundation

Measurement of the Low-Energy Antideuteron Inelastic Cross Section

In this Letter, we report the first measurement of the inelastic cross section for antideuteron-nucleus interactions at low particle momenta, covering a range of 0.3≤p<4  GeV/c. The measurement is carried out using p-Pb collisions at a center-of-mass energy per nucleon-nucleon pair of sqrt[s_{NN}]=5.02  TeV, recorded with the ALICE detector at the CERN LHC and utilizing the detector material as an absorber for antideuterons and antiprotons. The extracted raw primary antiparticle-to-particle ratios are compared to the results from detailed ALICE simulations based on the geant4 toolkit for the propagation of (anti)particles through the detector material. The analysis of the raw primary (anti)proton spectra serves as a benchmark for this study, since their hadronic interaction cross sections are well constrained experimentally. The first measurement of the inelastic cross section for antideuteron-nucleus interactions averaged over the ALICE detector material with atomic mass numbers ⟨A⟩=17.4 and 31.8 is obtained. The measured inelastic cross section points to a possible excess with respect to the Glauber model parametrization used in geant4 in the lowest momentum interval of 0.3≤p<0.47  GeV/c up to a factor 2.1. This result is relevant for the understanding of antimatter propagation and the contributions to antinuclei production from cosmic ray interactions within the interstellar medium. In addition, the momentum range covered by this measurement is of particular importance to evaluate signal predictions for indirect dark-matter searches.

Probing the Effects of Strong Electromagnetic Fields with Charge-Dependent Directed Flow in Pb-Pb Collisions at the LHC

The first measurement at the LHC of charge-dependent directed flow (v_{1}) relative to the spectator plane is presented for Pb-Pb collisions at sqrt[s_{NN}]=5.02  TeV. Results are reported for charged hadrons and D^{0} mesons for the transverse momentum intervals p_{T}>0.2  GeV/c and 3<p_{T}<6  GeV/c in the 5%-40% and 10%-40% centrality classes, respectively. The difference between the positively and negatively charged hadron v_{1} has a positive slope as a function of pseudorapidity η, dΔv_{1}/dη=[1.68±0.49(stat)±0.41(syst)]×10^{-4}. The same measurement for D^{0} and D[over ¯]^{0} mesons yields a positive value dΔv_{1}/dη=[4.9±1.7(stat)±0.6(syst)]×10^{-1}, which is about 3 orders of magnitude larger than the one of the charged hadrons. These measurements can provide new insights into the effects of the strong electromagnetic field and the initial tilt of matter created in noncentral heavy ion collisions on the dynamics of light (u, d, and s) and heavy (c) quarks. The large difference between the observed Δv_{1} of charged hadrons and D^{0} mesons may reflect different sensitivity of the charm and light quarks to the early time dynamics of a heavy ion collision. These observations challenge some recent theoretical calculations, which predicted a negative and an order of magnitude smaller value of dΔv_{1}/dη for both light flavor and charmed hadrons.