Project description:Preterm infants are highly susceptible to late-onset sepsis (LOS) and necrotizing enterocolitis (NEC) but specific biomarkers for diagnosis and effective treatment are lacking. Neutrophil extracellular traps (NETs) are related to sepsis in adults but not investigated in infant conditions. This is the first proteome study to document that circulating NETs are involved in neonatal LOS and NEC. cfDNA and NET proteins may provide new potential diagnostic markers for these diseases.
Project description:Bacterial sepsis is associated with high morbidity and mortality in preterm infants. However, diagnosis of sepsis and identification of the causative agent remains challenging. Our aim was to determine genome-wide expression profiles of very low birth weight (VLBW) infants with and without bacterial sepsis and assess differences.
Project description:Neonates manifest a unique host response to sepsis even among other children. Preterm neonates may experience sepsis soon after birth or during often protracted birth hospitalizations as they attain physiologic maturity. We examined the transcriptome using genome-wide expression profiling on prospectively collected peripheral blood samples from infants evaluated for sepsis within 24 hours after clinical presentation. Simultaneous plasma samples were examined for alterations in inflammatory mediators. Group designation (sepsis or uninfected) was determined retrospectively based on clinical exam and laboratory results over the next 72 hours from the time of evaluation. Unsupervised analysis showed the major node of separation between groups was timing of sepsis episode relative to birth (early, <3 days or late, >3 days). Principal component analyses revealed significant differences between patients with early or late sepsis despite the presence of similar key immunologic pathway aberrations in both groups. Unique to neonates, the uninfected state and host response to sepsis is significantly affected by timing relative to birth. Future therapeutic approaches may need to be tailored to the timing of the infectious event based on post-natal age. We used human microarrays to detail the molecular profile of the events that occur following sepsis in hospitalized neonates Please note that 'uninfected chorio' represents babies who were not infected but had chorioamnionitis exposure
Project description:With the successful implementation of guidelines from the Surviving Sepsis Campaign, in-hospital mortality to sepsis continues to decrease. However, this is has not lead to completely improved outcomes after sepsis. Up to 1/3 of sepsis survivors continue to have dismal long-term outcomes and 1-year mortality. Although the pathobiology of the dismal outcomes after sepsis remains undefined, it is thought that late after sepsis individuals enter a state of pathologic myeloid activation, inducing suboptimal lymphopoiesis and erythropoiesis, with many of the downstream immune cells being dysfunctional. The goal of this study was to use single-cell RNA sequencing to perform a detailed transcriptomic analysis of non-myeloid cells to better understand the pathology of late sepsis. Our findings highlight the unique transcriptomic pattern that circulating non-myeloid cells display 14 days after sepsis. Non-myeloid leukocytes in particular reveal an endotype of inflammation, immunosuppression and dysfunction. Immunomodulatory therapies at this late time point in sepsis may be feasible through precision medicine.
Project description:Neonates manifest a unique host response to sepsis even among other children. Preterm neonates may experience sepsis soon after birth or during often protracted birth hospitalizations as they attain physiologic maturity. We examined the transcriptome using genome-wide expression profiling on prospectively collected peripheral blood samples from infants evaluated for sepsis within 24 hours after clinical presentation. Simultaneous plasma samples were examined for alterations in inflammatory mediators. Group designation (sepsis or uninfected) was determined retrospectively based on clinical exam and laboratory results over the next 72 hours from the time of evaluation. Unsupervised analysis showed the major node of separation between groups was timing of sepsis episode relative to birth (early, <3 days or late, >3 days). Principal component analyses revealed significant differences between patients with early or late sepsis despite the presence of similar key immunologic pathway aberrations in both groups. Unique to neonates, the uninfected state and host response to sepsis is significantly affected by timing relative to birth. Future therapeutic approaches may need to be tailored to the timing of the infectious event based on post-natal age.
Project description:The aim of the project is to identify the late (24h) host response related to Gram positive (S. pyogenes) or Gram negative (E. coli) induced sepsis in a controlled sepsis model 24 hours a. Therefore a well defined baboon sepsis model, established at the Ludwig Boltzmann Institute for experimental and clinical traumatology of Vienna, is used. The overall goal of the project is to define differentially expressed or processed genes which give rise to diagnostic and therapeutic targets and consequently better monitoring and earlier onset of therapy.
Project description:Host immune responses during late-onset sepsis (LOS) in very preterm infants are poorly characterised due to a complex and dynamic pathophysiology and challenges in working with small available blood volumes. We present here an unbiased transcriptomic analysis of whole peripheral blood from very preterm infants at the time of LOS. RNA-Seq was performed on peripheral blood samples (6 – 29 days postnatal age) taken at the time of suspected LOS from very preterm infants <30 weeks gestational age. Infants were classified based on blood culture positivity and elevated C-reactive protein concentrations as having confirmed LOS (n=5), possible LOS (n=4) or no LOS (n=9). Bioinformatics and statistical analyses performed included pathway over-representation and protein-protein interaction network analyses. Plasma cytokine immunoassays were performed to validate differentially expressed cytokine pathways.The blood leukocyte transcriptional responses of infants with confirmed LOS differed significantly from infants without LOS (1,317 differentially expressed genes). However, infants with possible LOS could not be distinguished from infants with no LOS or confirmed LOS. Transcriptional alterations associated with LOS included genes involved in pathogen recognition (mainly TLR pathways), cytokine signalling (both pro-inflammatory and inhibitory responses), immune and haematological regulation (including cell death pathways), and metabolism (altered cholesterol biosynthesis). At the transcriptional-level cytokine responses during LOS were characterised by over-representation of IFN-α/β, IFN-γ, IL-1 and IL-6 signalling pathways and up-regulation of genes for inflammatory responses. Infants with confirmed LOS had significantly higher levels of IL-1α and IL-6 in their plasma. Blood responses in very preterm infants with LOS are characterised by altered host immune responses that appear to reflect unbalanced immuno-metabolic homeostasis.