Alarmin S100A9 restricts retroviral infection by limiting reverse transcription in human dendritic cells.

Dendritic cells (DC) subsets, like Langerhans cells (LC), are immune cells involved in pathogen sensing. They express specific antimicrobial cellular factors that are able to restrict infection and limit further pathogen transmission. Here, we identify the alarmin S100A9 as a novel intracellular antiretroviral factor expressed in human monocyte-derived and skin-derived LC. The intracellular expression of S100A9 is decreased upon LC maturation and inversely correlates with enhanced susceptibility to HIV-1 infection of LC. Furthermore, silencing of S100A9 in primary human LC relieves HIV-1 restriction while ectopic expression of S100A9 in various cell lines promotes intrinsic resistance to both HIV-1 and MLV infection by acting on reverse transcription. Mechanistically, the intracellular expression of S100A9 alters viral capsid uncoating and reverse transcription. S100A9 also shows potent inhibitory effect against HIV-1 and MMLV reverse transcriptase (RTase) activity in vitro in a divalent cation-dependent manner. Our findings uncover an unexpected intracellular function of the human alarmin S100A9 in regulating antiretroviral immunity in Langerhans cells.

Optimised prevention of postnatal HIV transmission in Zambia and Burkina Faso (PROMISE-EPI): a phase 3, open-label, randomised controlled trial.

BACKGROUND: Transmission through breastfeeding accounts for more than half of the unacceptably high number of new paediatric HIV infections worldwide. We hypothesised that, in addition to maternal antiretroviral therapy (ART), extended postnatal prophylaxis with lamivudine, guided by point-of-care assays for maternal viral load, could reduce postnatal transmission. METHODS: We did a phase 3, open-label, randomised controlled trial at four health-care facilities in Zambia and four health-care facilities in Burkina Faso. Mothers with HIV and their breastfed infants without HIV attending the second visit of the Expanded Programme of Immunisation (EPI-2; infant age 6-8 weeks) were randomly assigned 1:1 to intervention or control groups. In the intervention group, maternal viral load was measured using Xpert HIV viral load assay at EPI-2 and at 6 months, with results provided immediately. Infants whose mothers had a viral load of 1000 copies per mL or higher were started on lamivudine syrup twice per day for 12 months or 1 month after breastfeeding discontinuation. The control group followed national guidelines for prevention of postnatal transmission of HIV. The primary outcome assessed by modified intention to treat was infant HIV infection at age 12 months, with HIV DNA point-of-care testing at 6 months and at 12 months. This trial is registered with ClinicalTrials.gov (NCT03870438). FINDINGS: Between Dec 12, 2019 and Sept 30, 2021, 34 054 mothers were screened for HIV. Among them, 1506 mothers with HIV and their infants without HIV, including 1342 mother and infant pairs from Zambia and 164 from Burkina Faso, were eligible and randomly assigned 1:1 to the intervention (n=753) or control group (n=753). At baseline, the median age of the mothers was 30·6 years (IQR 26·0-34·7), 1480 (98·4%) of 1504 were receiving ART, and 169 (11·5%) of 1466 had a viral load ≥1000 copies/mL. There was one case of HIV transmission in the intervention group and six in the control group, resulting in a transmission incidence of 0·19 per 100 person-years (95% CI 0·005-1·04) in the intervention group and 1·16 per 100 person-years (0·43-2·53) in the control group, which did not reach statistical significance (p=0·066). HIV-free survival and serious adverse events were similar in both groups. INTERPRETATION: Our intervention, initiated at EPI-2 and based on extended single-drug postnatal prophylaxis guided by point-of-care maternal viral load could be an important strategy for paediatric HIV elimination. FUNDING: The EDCTP2 programme with the support of the UK Department of Health & Social Care.

Long-term persistence of mitochondrial dysfunctions after viral infections and antiviral therapies: A review of mechanisms involved.

Mitochondria are vital for most cells' functions. Viruses hijack mitochondria machinery for misappropriation of energy supply or to bypass defense mechanisms. Many of these mitochondrial dysfunctions persist after recovery from treated or untreated viral infections, particularly when mitochondrial DNA is permanently damaged. Quantitative defects and structural rearrangements of mitochondrial DNA accumulate in post-mitotic tissues as recently reported long after SARS-CoV-2 or HIV infection, or following antiviral therapy. These observations are consistent with the "hit-and-run" concept proposed decades ago to explain viro-induced cell transformation and it could apply to delayed post-viral onsets of symptoms and advocate for complementary supportive care. Thus, according to this concept, following exposure to viruses or antiviral agents, mitochondrial damage could evolve into an autonomous clinical condition. It also establishes a pathogenic link between communicable and non-communicable chronic diseases.

SARS-CoV-2 nucleocapsid antigen in plasma of children hospitalized for COVID-19 or with incidental detection of SARS-CoV-2 infection.

In hospitalized children, SARS-CoV-2 infection can present as either a primary reason for admission (patients admitted for COVID-19) or an incidental finding during follow-up (patients admitted with COVID-19). We conducted a nested case-control study within a cohort of pediatric patients with confirmed SARS-CoV-2 infection, to investigate the concentration of plasma nucleocapsid antigen (N-Ag) in children admitted for COVID-19 or with COVID-19. While reverse transcriptase polymerase chain reaction Ct values in nasopharyngeal swab were similar between the two groups, children admitted for COVID-19 had a higher rate of detectable N-Ag (12/18 (60.7%) versus 6/18 (33.3%), p = 0.0455) and a higher concentration of N-Ag (medians: 19.51 g/mL vs. 1.08 pg/mL, p = 0.0105). In children hospitalized for COVID-19, the youngest had higher concentration of N-Ag (r = -0.74, p = 0.0004). We also observed a lower prevalence of detectable spike antibodies in children hospitalized for COVID-19 compared to those hospitalized for other medical reasons (3/15 [20%] vs. 13/16 [81.25%], respectively, p = < 0.0011), but similar rates of IgG nucleocapsid antibodies (5/14 [35.7%] vs. 6/17 [35.3%], respectively, p = 0.99). Our findings indicate that N-Ag is associated with COVID-19-related hospitalizations in pediatric patients, and less frequently detected in children tested positive for SARS-CoV-2 but hospitalized for another medical reason. Further studies are needed to confirm the value of N-Ag in identifying COVID-19 disease infections in which SARS-CoV-2 is the main pathogen responsible for symptoms.

Using adult care visits to diagnose HIV infection in children, Burkina Faso.

Objective: To estimate the feasibility, positivity rate and cost of offering child testing for human immunodeficiency virus (HIV) to mothers living with HIV attending outpatient clinics in Burkina Faso. Methods: We conducted this implementation study in nine outpatient clinics between October 2021 and June 2022. We identified all women ≤ 45 years who were attending these clinics for their routine HIV care and who had at least one living child aged between 18 months and 5 years whose HIV status was not known. We offered these mothers an HIV test for their child at their next outpatient visit. We calculated intervention uptake, HIV positivity rate and costs. Findings: Of 799 eligible children, we tested 663 (83.0%) and identified 16 new HIV infections: 2.5% (95% confidence interval, CI: 1.5-4.1). Compared with HIV-negative children, significantly more HIV-infected children were breastfed beyond 12 months (P-value: 0.003) and they had not been tested before (P-value: 0.003). A significantly greater proportion of mothers of HIV-infected children were unaware of the availability of child testing at 18 months (P-value: < 0.001) and had more recently learnt their HIV status (P-value: 0.01) than mothers of HIV-negative children. The intervention cost 98.1 United States dollars for one child testing HIV-positive. Barriers to implementing this strategy included shortages of HIV tests, increased workload for health-care workers and difficulty accessing children not living with their mothers. Conclusion: Testing HIV-exposed children through their mothers in outpatient clinics is feasible and effective in a low HIV-prevalence setting such as Burkina Faso. Implementation of this strategy to detect undiagnosed HIV-infected children is recommended.

An optimized strategy triggered at the 2nd immunization visit to prevent HIV acquisition by breastfeeding: a phase 2 trial in Burkina Faso (PREVENIR-PEV).

BACKGROUND: Mother-to-child transmission of HIV during breastfeeding remains a challenge in low- and middle-income countries (LMIC). A prevention package was initiated during the highly attended 2nd visit of the Expanded Program of Immunisation (EPI-2) to identify the undiagnosed infants living with HIV and reduce the postnatal transmission of infant exposed to HIV. METHODS: PREVENIR-PEV is a non-randomized phase II clinical trial conducted at two health centres in Bobo Dioulasso (Burkina Faso). The study recruited mothers living with HIV aged 15 years and older with their singleton breastfed infants. During EPI-2 (at 8 weeks) and upon signature of the informed consent, a point-of-care early infant diagnosis (EID) was performed. HIV exposed uninfected (HEU) infants were followed-up until 12 months of age. High risk HEU infants (i.e., whose maternal viral load ≥ 1000 cp/mL at EPI-2 or M6) received an extended postnatal prophylaxis (PNP) with lamivudine until end of follow-up or the end of breastfeeding. RESULTS: Between 4 December 2019 and 4 December 2020, 118 mothers living with HIV-1 were identified, and 102 eligible mother/infant pairs had their infants tested for HIV EID. Six infants were newly diagnosed with HIV, and 96 HEU infants were followed-up for 10 months. Among the participants followed-up, all mothers were prescribed antiretrovirals. All 18 infants eligible for PNP at either EPI-2 or 6 months (M6) were initiated on lamivudine. No HIV transmission occurred, and no serious adverse events were reported in infants receiving lamivudine. CONCLUSIONS: The PREVENIR-PEV prevention package integrated into existing care is safe and its implementation is feasible in a LMIC with a low HIV prevalence. More research is needed to target mother/infant pairs not adhering to the intervention proposed in this trial. TRIAL REGISTRATION: NCT03869944; first registered on 11/03/2019.

Safety and pharmacokinetics of subcutaneous administration of broadly neutralizing anti-HIV-1 monoclonal antibodies (bNAbs), given to HIV-1 exposed, uninfected neonates and infants: study protocol for a phase I trial.

BACKGROUND: The ambitious goal to eliminate new pediatric HIV infections by 2030 requires accelerated prevention strategies in high-risk settings such as South Africa. One approach could be pre-exposure prophylaxis (PrEP) with broadly neutralizing anti-HIV-1 monoclonal antibodies (bNAbs). The aim of our study is to define the optimal dose(s), the ideal combination(s) of bNAbs in terms of potency and breadth, and timing of subcutaneous (SC) administration(s) to prevent breast milk transmission of HIV. METHODS: Two bNAbs, CAP256V2LS and VRC07-523LS, will be assessed in a sequential and randomized phase I, single-site, single-blind, dose-finding trial. We aim to investigate the 28-day safety and pharmacokinetics (PK) profile of incrementally higher doses of these bNAbs in breastfeeding HIV-1 exposed born without HIV neonates alongside standard of care antiretroviral (ARV) medication to prevent (infants) or treat (mothers) HIV infection. The trial design includes 3 steps and 7 arms (1, 2, 3, 4, 5, 6 and 6b) with 8 infants in each arm. The first step will evaluate the safety and PK profile of the bNAbs when given alone as a single subcutaneous (SC) administration at increasing mg/kg body weight doses within 96 h of birth: arms 1, 2 and 3 at doses of 5, 10, and 20 mg/kg of CAP256V2LS, respectively; arms 4 and 5 at doses of 20 and 30 mg/kg of VRC07-523LS, respectively. Step two will evaluate the safety and PK profile of a combination of the two bNAbs administered SC at fixed doses within 96 h of birth. Step three will evaluate the safety and PK profile of the two bNAbs administered SC in combination at fixed doses, after 3 months. Arms 1 and 6 will follow sequential recruitment, whereas randomization will occur sequentially between arms (a) 2 & 4 and (b) 3 & 5. Before each randomization, a safety pause will allow review of safety data of the preceding arms. DISCUSSION: The results of this trial will guide further studies on bNAbs to prevent breast milk transmission of HIV. PROTOCOL VERSION: Version 4.0 dated 15 March 2024. TRIAL REGISTRATION: Pan African Clinical Trial Registry (PACTR): PACTR202205715278722, 21 April 2022; South African National Clinical Trial Registry (SANCTR): DOH-27-062022-6058.

Severe Acute Respiratory Syndrome Coronavirus 2 Nucleocapsid Antigen in Urine of Hospitalized Patients With Coronavirus Disease 2019.

BACKGROUND: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) nucleocapsid antigen (N-Ag) can be detected in the blood of patients with coronavirus disease 2019 (COVID-19). We used a highly sensitive and specific assay to explore the presence of N-Ag in urine during the course of COVID-19 and its relationship with the severity of disease. METHODS: We studied urinary and plasma N-Ag using a highly sensitive immunoassay in 82 patients with SARS-CoV-2 infection proved by polymerase chain reaction. RESULTS: In the first and second weeks of COVID-19, hospitalized patients tested positive for urinary N-Ag (81.25% and 71.79%, respectively) and plasma N-Ag (93.75% and 94.87%, respectively). High urinary N-Ag levels were associated with the absence of SARS-CoV-2 nucleocapsid antibodies, admission in intensive care units, high C-reactive protein levels, lymphopenia, eosinopenia, and high lactate dehydrogenase levels. Higher accuracy was observed for urinary N-Ag as a predictor of severe COVID-19 than for plasma N-Ag. CONCLUSIONS: Our study demonstrates that N-Ag is present in the urine of patients hospitalized in the early phase of COVID-19. As a direct marker of SARS-CoV-2, urinary N-Ag reflects the dissemination of viral compounds in the body. Urinary N-Ag may be a useful marker for disease severity in SARS-CoV-2 infections.

Eliminating postnatal HIV transmission in high incidence areas: need for complementary biomedical interventions.

The rate of mother-to-child transmission (MTCT) of HIV from breastfeeding is increasing relative to other causes of MTCT. Early effective preconception and antenatal antiretroviral therapy (ART) reduces intrauterine and intrapartum MTCT, whereas maternal post-partum HIV acquisition, untreated maternal HIV, and suboptimal postnatal maternal ART adherence increase the risk of MTCT through breastfeeding. Although the absolute number of cases of MTCT acquired through breastfeeding is decreasing, the rate of decrease is less than the decrease in intrauterine and intrapartum MTCT. Unless current strategies are universally applied, they might not be sufficient to eliminate MTCT due to breastfeeding. Urgent action is needed to evaluate and implement additional preventive biomedical strategies in high HIV prevalence and incidence settings to eliminate MTCT from breastfeeding. Preventive strategies include: pre-exposure prophylaxis in breastfeeding women who have an increased risk of acquiring HIV; postnatal reinforcement strategies, such as maternal retesting for HIV, maternal care reinforcement, and prophylaxis in infants exposed to HIV via breastmilk; and active (vaccine) or passive immunoprophylaxis with long-acting broadly neutralising antibodies.

Screening for Hepatitis B in partners and children of women positive for surface antigen, Burkina Faso.

Objective: To evaluate the implementation of a screening strategy for the partners and children of pregnant women with hepatitis B virus (HBV) attending antenatal care. Methods: We identified pregnant women positive for HBV surface antigen (HBsAg) at antenatal consultation in Ouagadougou, Burkina Faso. At post-test counselling, women were advised to disclose their HBV status to partners and to encourage their partner and children to be screened for HBsAg. We used multivariable logistic regression to explore factors associated with uptake of screening and HBsAg positivity among family members. Findings: Of 1000 HBsAg-positive women, 436/1000 partners and 215/1281 children were screened. HBsAg was detected in 55 (12.6%) partners and 24 (11.2%) children. After adjusting for confounders, uptake of screening was higher in partners who were married, who attended the woman's first post-test consultation and to whom the woman had disclosed her HBV status. In children, HBsAg positivity was associated with being born before the introduction of infant hepatitis B vaccination in Burkina Faso (not significant in the multivariable analysis), having a mother positive for HBV e-antigen (adjusted OR: 8.57; 95% CI: 2.49-29.48) or having a mother with HBV DNA level ≥ 200 000 IU/mL (OR: 6.83; 95% CI: 1.61-29.00). Conclusion: In low-income countries, the antenatal consultation provides a cost-effective opportunity to identify HBV-infected household contacts and link them to care. Children born before the introduction of infant hepatitis B vaccination and whose mother has higher viral load or infectivity should be a priority for testing and linkage to care.