Proteomic profiling reveals diagnostic signatures and pathogenic insights in multisystem inflammatory syndrome in children.

Multisystem inflammatory syndrome in children (MIS-C) is a severe disease that emerged during the COVID-19 pandemic. Although recognized as an immune-mediated condition, the pathogenesis remains unresolved. Furthermore, the absence of a diagnostic test can lead to delayed immunotherapy. Using state-of-the-art mass-spectrometry proteomics, assisted by artificial intelligence (AI), we aimed to identify a diagnostic signature for MIS-C and to gain insights into disease mechanisms. We identified a highly specific 4-protein diagnostic signature in children with MIS-C. Furthermore, we identified seven clusters that differed between MIS-C and controls, indicating an interplay between apolipoproteins, immune response proteins, coagulation factors, platelet function, and the complement cascade. These intricate protein patterns indicated MIS-C as an immunometabolic condition with global hypercoagulability. Our findings emphasize the potential of AI-assisted proteomics as a powerful and unbiased tool for assessing disease pathogenesis and suggesting avenues for future interventions and impact on pediatric disease trajectories through early diagnosis.

Host RNA Expression Signatures in Young Infants with Urinary Tract Infection: A Prospective Study.

Early diagnosis of infections in young infants remains a clinical challenge. Young infants are particularly vulnerable to infection, and it is often difficult to clinically distinguish between bacterial and viral infections. Urinary tract infection (UTI) is the most common bacterial infection in young infants, and the incidence of associated bacteremia has decreased in the recent decades. Host RNA expression signatures have shown great promise for distinguishing bacterial from viral infections in young infants. This prospective study included 121 young infants admitted to four pediatric emergency care departments in the capital region of Denmark due to symptoms of infection. We collected whole blood samples and performed differential gene expression analysis. Further, we tested the classification performance of a two-gene host RNA expression signature approaching clinical implementation. Several genes were differentially expressed between young infants with UTI without bacteremia and viral infection. However, limited immunological response was detected in UTI without bacteremia compared to a more pronounced response in viral infection. The performance of the two-gene signature was limited, especially in cases of UTI without bloodstream involvement. Our results indicate a need for further investigation and consideration of UTI in young infants before implementing host RNA expression signatures in clinical practice.

Oral-only antibiotics for bone and joint infections in children: study protocol for a nationwide randomised open-label non-inferiority trial.

INTRODUCTION: Children with bone and joint infections are traditionally treated with intravenous antibiotics for 3-10 days, followed by oral antibiotics. Oral-only treatment has not been tested in randomised trials. METHODS AND ANALYSIS: Children (3 months to 18 years) will be randomised 1:1 with the experimental group receiving high-dose oral antibiotics and the control group receiving intravenous antibiotics with a shift in both groups to standard oral antibiotics after clinical and paraclinical improvement. Children in need of acute surgery or systemic features requiring intravenous therapy, including septic shock, are excluded. The primary outcome is defined as a normal blinded standardised clinical assessment 6 months after end of treatment. Secondary outcomes are non-acute treatment failure and recurrent infection. Outcomes will be compared by a non-inferiority assumption with an inferiority margin of 5%. ETHICS AND DISSEMINATION: The trial has the potential to reduce unnecessary hospitalisation and use of intravenous antibiotics in children with bone or joint infections. Due to the close follow-up, exclusion of severely ill children and predefined criteria for discontinuation of the allocated therapy, we expect the risk of treatment failure to be minimal. TRIAL REGISTRATION NUMBER: NCT04563325.

Prevalence of SARS-CoV-2-Antibodies in Danish Children and Adults.

In Denmark, severe acute respiratory syndrome coronavirus 2 antibodies were assessed in a cross-sectional study among 1033 children visiting pediatric departments and 750 blood donors in June 2020, using a point-of-care test. Antibodies were detected in 17 children (1.6%) and 15 blood donors (2.0%) (P = 0.58). In conclusion, children and adults were infected to a similar low degree.

Children Hospitalized With Varicella in Denmark: Sensitivity of the National Patient Register.

BACKGROUND: Varicella, common in childhood and most often self-limiting, may cause complications including bacterial superinfection, pneumonia and encephalitis. Universal childhood varicella vaccination has been introduced in several countries, but is controversial in Europe. In Denmark, varicella is not part of the national immunization program and there is no national surveillance of varicella. The primary aim of the study was to describe the epidemiology and clinical characteristics of children hospitalized with varicella in Denmark. The secondary aim was to validate the sensitivity and completeness of the Danish National Patient Register. METHODS: Active surveillance of children hospitalized with varicella was carried out at 4 pediatric departments. In the Danish National Patient Register, we identified all children discharged with an International Classification of Diseases, 10th revision code of varicella from the 4 departments. We used a capture-recapture analysis to estimate the "true" number of hospitalized children with varicella. RESULTS: By active surveillance, we identified 86 children eligible for clinical description. In 87% of cases, the children were 0-4 years of age. Complications were identified in 69% of patients, including 1 child with postvaricella cerebral angiopathy. In the National Patient register (NPR), we identified 125 children with a discharge diagnosis of varicella. By capture-recapture analysis, the sensitivity of the NPR was estimated to be 74%. CONCLUSIONS: Varicella can cause serious complications including cerebral angiopathy in children in Denmark. The NPR will be a useful tool for estimating hospitalization incidence, but will underestimate the true number of hospitalizations.