Publications by authors named "Arnaud L'huillier"

Pediatric solid organ transplant (SOT) recipients with splenic dysfunction are at increased risk for infections, and tailored guidance on the management of asplenia/hyposplenism among SOT recipients is often lacking. The purpose of this article is to provide practice recommendations via a frequently asked questions (FAQs) format that focuses on three main domains: the identification of asplenia/hyposplenism among SOT recipients/candidates, prophylactic strategies for mitigating the risk of invasive disease associated with splenic dysfunction in the context of transplantation, and the provision of appropriate patient counseling on the risks associated with asplenia/hyposplenism. Answers to the FAQs are based on international expert opinion informed by practices for managing splenic dysfunction and associated data in other populations with asplenia.

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Background: Pediatric post-COVID syndrome (pPCS) affects a notable number of children. This study aims to describe its clinical manifestations, biopsychosocial impact and management strategies.

Methods: A prospective, single-center study was conducted to analyze data of pPCS patients presenting to our institution between May 2021 and November 2022.

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Cytomegalovirus is the most common cause of congenital infection worldwide. 90 % of children infected in utero are born without symptoms, but 15 % of them will develop disorders within the first five years of life. The most common disorders affect the inner ear, resulting in sensorineural hearing loss and/or vestibular dysfunction (VD).

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Article Synopsis
  • - Carbapenem-resistant Enterobacterales are rising in frequency, leading to hospital-acquired infections like postoperative mediastinitis.
  • - A case study details a 13-month-old boy with DiGeorge syndrome who developed this infection from an Escherichia coli strain producing NDM-1 carbapenemase.
  • - The boy was treated successfully with surgery and a combination of antibiotics over 6 weeks, showing positive recovery without any relapses in a follow-up period of 10 weeks.
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Liver transplantation (LT) recipients are susceptible to infections, including measles. Concerns about the safety and efficacy of live-attenuated vaccines, such as the measles-mumps-rubella (MMR) vaccine, have led to hesitancy among providers in administering them to immunocompromised patients. This 9-year interventional study assessed seroprotection against measles following MMR vaccination in pediatric LT recipients.

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Article Synopsis
  • * Strong recommendations include reducing immunosuppression as an initial management step and using the anti-CD20 monoclonal antibody (rituximab), as well as chemotherapy in specific cases.
  • * There is a lack of large randomized phase III trials for treating PTLD in pediatrics, leading to reliance on clinical experience, and the report emphasizes the need for future research on this topic.
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  • Epstein-Barr Virus (EBV) can lead to serious health issues, like post-transplant lymphoproliferative disorder (PTLD), particularly in children who have undergone organ transplants.
  • Despite advancements in preventing EBV-related diseases, there are still many unanswered questions regarding their management and prevention.
  • This manuscript aims to outline important recommendations from expert guidelines for managing EBV risks in pediatric patients undergoing solid organ and hematopoietic cell transplants, along with insights on measuring EBV viral loads.
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Infective endocarditis due to is a rare but serious invasive infection that occurs mostly in children. Recent advances in nucleic acid amplification testing as well as in cardiac imaging have enabled more accurate diagnosis. A good understanding of the epidemiology and virulence factors remains crucial to guide the therapeutic approach.

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Background: Improved tools are required to detect bacterial infection in children with fever without source (FWS), especially when younger than 3 years old. The aim of the present study was to investigate the diagnostic accuracy of a host signature combining for the first time two viral-induced biomarkers, tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) and interferon γ-induced protein-10 (IP-10), with a bacterial-induced one, C-reactive protein (CRP), to reliably predict bacterial infection in children with fever without source (FWS) and to compare its performance to routine individual biomarkers (CRP, procalcitonin (PCT), white blood cell and absolute neutrophil counts, TRAIL, and IP-10) and to the Labscore.

Methods: This was a prospective diagnostic accuracy study conducted in a single tertiary center in children aged less than 3 years old presenting with FWS.

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Objectives: Infections by SARS-CoV-2 variants of concern (VOCs) might affect children and adolescents differently than earlier viral lineages. We aimed to address five questions about SARS-CoV-2 VOC infections in children and adolescents: (1) symptoms and severity, (2) risk factors for severe disease, (3) the risk of infection, (4) the risk of transmission and (5) long-term consequences following a VOC infection.

Design: Systematic review.

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Article Synopsis
  • The International Pediatric Transplant Association held a conference to create guidelines for managing post-transplant lymphoproliferative disorders (PTLD) in children, focusing on how to use biomarkers like Epstein-Barr virus (EBV) levels for patient care.
  • The group recommends using "EBV DNAemia" for measuring EBV DNA in blood and advises caution when comparing results from different labs. They concluded both whole blood and plasma can be used for testing, depending on the clinical situation.
  • It is suggested that quantitative EBV DNAemia testing can help identify children at risk for PTLD, especially those who were EBV negative before their transplant, but overall routine surveillance is not recommended for
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Objective: We aimed to examine factors associated with parental willingness to vaccinate their children against COVID-19.

Methods: We surveyed adults included in a digital longitudinal cohort study composed of participants in previous SARS-CoV-2 serosurveys conducted in Geneva, Switzerland. In February 2022, an online questionnaire collected information on COVID-19 vaccination acceptance, parental willingness to vaccinate their children aged ≥5 years and reasons for vaccination preference.

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Objectives: To comprehensively analyze the quality of the antibody response between children with Multisystem inflammatory syndrome (MIS-C) and age-matched controls at one month after SARS-CoV-2 exposure, and infected in the same time-period.

Methods: Serum from 20 MIS-C children at admission, and 14 control children were analyzed. Antigen specific antibody isotypes and subclasses directed against various antigens of SARS-CoV-2 as well as against human common coronavirus (HCoVs) and commensal or pathogenic microorganisms were assessed by a bead-based multiplexed serological assay and by ELISA.

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Objectives: We evaluate the diagnostic performance of dried blood microsampling combined with a high-throughput microfluidic nano-immunoassay (NIA) for the identification of anti-SARS-CoV-2 Spike IgG seropositivity.

Methods: We conducted a serological study among 192 individuals with documented prior SARS-CoV-2 infection and 44 SARS-CoV-2 negative individuals. Participants with prior SARS-CoV-2 infection had a long interval of 11 months since their qRT-PCR positive test.

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Post-COVID syndrome remains poorly studied in children and adolescents. Here, we aimed to investigate the prevalence and risk factors of pediatric post-COVID in a population-based sample, stratifying by serological status. Children from the SEROCoV-KIDS cohort study (State of Geneva, Switzerland), aged 6 months to 17 years, were tested for anti-SARS-CoV-2 N antibodies (December 2021-February 2022) and parents filled in a questionnaire on persistent symptoms in their children (lasting over 12 weeks) compatible with post-COVID.

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Objectives: To estimate the prevalence of children and adolescents reporting persistent symptoms after SARS-CoV-2 infection.

Design: A random sample of children and adolescents participated with their family members to a serological survey including a blood drawing for detecting antibodies targeting the SARS-CoV-2 nucleocapsid (N) protein and a questionnaire on COVID-19-related symptoms experienced since the beginning of the pandemic.

Setting: The study took place in the canton of Geneva, Switzerland, between June and July 2021.

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Article Synopsis
  • Lots of kids get fevers without a clear reason, and doctors usually run tests to see if they have a serious infection, often treating them with antibiotics.
  • This study looked at whether finding a virus in a child's blood could help doctors decide if there's a serious infection or not.
  • It turns out that if a virus is found, it’s really good (90% accurate) at showing there’s no serious infection, even better than the usual blood tests they use.
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The International Pediatric Transplant Association (IPTA) convened an expert consensus conference to assess current evidence and develop recommendations for various aspects of care relating to post-transplant lymphoproliferative disorder after solid organ transplantation in children. In this report from the Prevention Working Group, we reviewed the existing literature regarding immunoprophylaxis and chemoprophylaxis, and pre-emptive strategies. While the group made a strong recommendation for pre-emptive reduction of immunosuppression at the time of EBV DNAemia (low to moderate evidence), no recommendations for use could be made for any prophylactic strategy or alternate pre-emptive strategy, largely due to insufficient or conflicting evidence.

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Objectives: To report a prospective epidemiological, virological and serological investigation of a SARS-CoV-2 outbreak in a primary school.

Methods: As part of a longitudinal, prospective, school-based surveillance study, this investigation involved repeated testing of 73 pupils, 9 teachers, 13 non-teaching staff and 26 household members of participants who tested positive, with rapid antigen tests and/or RT-PCR (Day 0-2 and Day 5-7), serologies on dried capillary blood samples (Day 0-2 and Day 30), contact tracing interviews and SARS-CoV-2 whole genome sequencing.

Results: We identified 20 children (aged 4 to 6 years from 4 school classes), 2 teachers and a total of 4 household members who were infected by the Alpha variant during this outbreak.

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Emerging SARS-CoV-2 variants raise questions about escape from previous immunity. As the population immunity to SARS-CoV-2 has become more complex due to prior infections with different variants, vaccinations or the combination of both, understanding the antigenic relationship between variants is needed. Here, we have assessed neutralizing capacity of 120 blood specimens from convalescent individuals infected with ancestral SARS-CoV-2, Alpha, Beta, Gamma or Delta, double vaccinated individuals and patients after breakthrough infections with Delta or Omicron-BA.

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Article Synopsis
  • SARS-CoV-2 infection leads to the development of auto-antibodies, specifically anti-apolipoprotein A-1 IgGs (AAA1), which may play a role in lingering symptoms after COVID-19.
  • A study tracked AAA1 levels in hospital employees with COVID-19 over twelve months and found that AAA1 positivity dropped from 93% at one month to 15% at twelve months, while 45.1% of participants reported persistent symptoms.
  • Results indicated that AAA1 levels are a predictor of persistent respiratory symptoms after COVID-19, potentially through increasing the production of Interferon-α, suggesting a need for further research on the usefulness of measuring AAA1 in COVID-19 risk assessment
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Multisystem inflammatory syndrome in children (MIS-C) represents a rare but severe complication of severe acute respiratory syndrome coronavirus 2 infection affecting children that can lead to myocardial injury and shock. Vascular endothelial dysfunction has been suggested to be a common complicating factor in patients with coronavirus disease 2019 (COVID-19). This study aims to characterize endothelial glycocalyx degradation in children admitted with MIS-C.

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Background: COVID-19 vaccination has been successful in decreasing rates of SARS-CoV-2 infection in areas with high vaccine uptake. Cases of breakthrough SARS-CoV-2 infection remain infrequent among immunocompetent vaccine recipients who are protected from severe COVID-19. Robust data demonstrate the safety, immunogenicity, and effectiveness of several COVID-19 vaccine formulations.

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Antigen-based rapid diagnostic tests (RDTs) are used in children despite the lack of data. We evaluated the diagnostic performance of the Panbio-COVID-19 Ag Rapid Test Device (P-RDT) in children. Symptomatic and asymptomatic participants 0 to 16 years old had two nasopharyngeal swabs (NPS) for both reverse transcription-PCR (RT-PCR) and P-RDT.

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