Pediatric Sepsis: Determinants of outcome

Bacterial infections are one of the leading causes of death and disability among children. The host response to infection involves complex interplays between inflammation, coagulation, and fibrinolysis. In meningococcal sepsis, the inflammatory response induce excessive coagulation and downregulation of fibrinolysis, contributing to the need to amputate extremities, multiple organ dysfunction, and eventually death. In this thesis, we characterized children with severe bacterial infections and we studied the following six determinants in relation to outcome: neutrophil extracellular traps (NETs), human leukocyte antigen-DR (HLA-DR) expression on monocyte subsets, glycosylation of the fragment crystallizable (Fc) region of immunoglobulin G (IgG), A Disintegrin and Metalloproteinase with Thrombospondin motifs (ADAMTS)-1, ADAMTS-18, and plasminogen-activator-inhibitor-1 (PAI-1). In addition, we explored the role of genetic variation within individuals in the host response to infection. This thesis shows that community-acquired sepsis continues to cause a devastating effect in high-income countries, mainly by high incidence of disability. Furthermore, this thesis provides considerable insight into the host response to sepsis by studying specific inflammatory, hemostatic, genetic, and environmental factors in relation to outcome. These determinants could help to detect patients at risk for poor outcome at an early stage, and have given us new directions to individualize sepsis treatment

The Inflammatory and Hemostatic Response in Sepsis and Meningococcemia

Meningococcemia is notorious for evasion of the host immune system and its rapid progression to fulminant disease, and serves as a unique model for pediatric sepsis. Illness severity is determined by complex interplays among host, pathogen, and environment. The inflammatory host response, including proinflammatory and anti-inflammatory responses in innate and adaptive immunity, skews toward a proinflammatory state. This leads to endothelial dysfunction and activation of the hemostatic response, which may lead to disseminated intravascular coagulation. This article reviews the pathogenesis of sepsis, in particular the inflammatory and hemostatic response in meningococcal sepsis

Circadian variation of plasminogen-activator-inhibitor-1 levels in children with meningococcal sepsis

Objective To study whether the circadian variation of plasminogen-activator-inhibitor-1 (PAI-1) levels, with high morning levels, is associated with poor outcome of children with meningococcal sepsis presenting in the morning hours. Design Retrospective analysis of prospectively collected clinical and laboratory data. Setting Single center study at Erasmus MC-Sophia Children's Hospital, Rotterdam, the Netherlands. Subjects 184 patients aged 3 weeks to 18 years with meningococcal sepsis. In 36 of these children, PAI-1 levels at admission to the PICU were measured in plasma by ELISA. Interventions None. Measurements and main results Circadian variation was studied by dividing one day in blocks of 6 hours. Patients admitted between 6:00 am and 12:00 am had increased illness severity scores and higher PAI-1 levels (n = 9, median 6912 ng/mL, IQR 5808-15600) compared to patients admitted at night (P = 0.019, n = 9, median 3546 ng/mL, IQR 1668-6118) or in the afternoon (P = 0.007, n = 7, median 4224 ng/mL, IQR 1804-5790). In 184 patients, analysis of circadian variation in relation to outcome showed more deaths, amputations and need for skin grafts in patients admitted to the PICU between 6:00 am and 12:00 am than patients admitted during the rest of the day (P = 0.009). Conclusions Circadian variation of PAI-1 levels is present in children with meningococcal sepsis and is associated with illness severity, with a peak level in the morning. Whether circadian variation is an independent risk factor for morbidity and mortality in meningococcal sepsis needs to be explored in future studies

Aplicación de un proceso de curtido de pieles bovinas sin cromo utilizando oxazolidina en combinación con Caelsalpinia spinosa (tara)

Publicación a texto completo no autorizada por el autorEstablece la relación de las propiedades físico mecánicas con el proceso de curtido de pieles bovinas sin cromo utilizando oxazolidina en combinación con Caelsalpinia spinosa (Tara), establecer la relación de las pruebas sensoriales con el proceso de curtido de pieles bovinas sin cromo y determinar el comportamiento funcional del cuero en la confección de portafolios que podrán ser eco etiquetados como productos libres de cromo. Para realizar la evaluación de una curtición con diferentes niveles de Caelsalpinia spinosa (12, 15 y 18%) en combinación con 5% de oxazolidina, destinados a la confección de marroquinería, se utilizaron 15 pieles vacunas distribuidas en 3 tratamientos, con 10 repeticiones cada uno. Los resultados para las pruebas físicas de los cueros de la tercera etapa de investigación fueron resistencia a la tracción los valores más altos se reportaron en el tratamiento T2 con respuestas de 2214,49 N/cm2, para el porcentaje de elongación los resultados más altos se reportaron en los cueros del tratamiento T1, con resultados de 94,38% y para la resistencia al desgarro los resultados más altos se reportaron en el tratamiento T2 (tara), con valores medios de 109,05 N. Con esto se concluyó que la curtición con oxazolidina, combinada con Caelsalpinia spinosa, permite obtener pieles curtidas excelentes propiedades físicas, sensoriales y una elevada estabilidad frente a los procesos de fabricación y el paso del tiempo, ya que consigue evitar la presencia especialmente de cromo III, tanto en los residuos líquidos como sólidos, para reducir considerablemente el impacto ambiental.Tesi

Translating Sepsis-3 criteria in children: Prognostic accuracy of age-adjusted quick SOFA score in children visiting the emergency department with suspected bacterial infection

Background: Recent attempts to translate Sepsis-3 criteria to children have been restricted to PICU patients and did not target children in emergency departments (ED). We assessed the prognostic accuracy of the age-adjusted quick Sequential Organ Failure Assessment score (qSOFA) and compared the performance to SIRS and the quick Pediatric Logistic Organ Dysfunction-2 score (qPELOD-2). We studied whether the addition of lactate (qSOFA-L) would increase prognostic accuracy. Methods: Non-academic, single-center, retrospective study in children visiting the ED and admitted with suspected bacterial infection between March 2013 and January 2018. We defined suspected bacterial infection as initiation of antibiotic therapy within 24 h after ED entry. Age-adjusted qSOFA, SIRS, qPELOD-2, and qSOFA-L scores were compared by area under the receiver operating characteristics curve (AUROC) analysis. Primary outcome measure was PICU transfer and/or mortality and secondary outcome was prolonged hospital length of stay. Results: We included 864 ED visits [474 (55%) male; median age 2.5 years; IQR 9 months-6 years], of which 18 were transferred to a PICU and 6 ended in death [composite outcome PICU transfer and/or mortality; 23 admissions (2.7%)]. 179 (22.2%) admissions resulted in prolonged hospital length of stay. PICU transfer and/or death was present in 22.5% of visits with qSOFA≥2 (n = 40) compared to 2.0% of visits with qSOFA < 2 (n = 444) (p < 0.01). qSOFA tends to be the best predictor of PICU transfer and/or mortality (AUROC 0.72 (95% CI, 0.57-0.86) compared to SIRS [0.64 (95% CI, 0.53-0.74), p = 0.23] and qPELOD-2 [0.60 (95% CI, 0.45-0.76), p = 0.03)]. Prolonged hospital length of stay was poorly predicted by qSOFA (AUROC 0.53, 95% CI 0.46-0.59), SIRS (0.49, 95% CI 0.44-0.54), and qPELOD-2 (0.51, 95%CI 0.45-0.57). qSOFA-L resulted in an AUROC of 0.67 (95%CI, 0.50-0.84) for PICU transfer and/ormortality and an AUROC of 0.56 (95% CI, 0.46-0.67) for prolonged hospital length of stay. Conclusion: The currently proposed bedside risk-stratification tool of Sepsis-3 criteria, qSOFA, shows moderate prognostic accuracy for PICU transfer and/or mortality in children visiting the ED with suspected bacterial infection. The addition of lactate did not improve prognostic accuracy. Future prospective studies in larger ED populations are needed to further determine the utility of the qSOFA score

Target attainment of cefotaxime in critically ill children with meningococcal septic shock as a model for cefotaxime dosing in severe pediatric sepsis

Reduced target attainment of β-lactam antibiotics is reported in critically ill patients. However, as target attainment of cefotaxime in severely ill pediatric sepsis patients may differ from adults due to age-related variation in pharmacokinetics, we aimed to assess target attainment of cefotaxime in this pilot study using meningococcal septic shock patients as a model for severe sepsis. Secondary analysis of prospectively collected data from a randomized controlled trial. Children with meningococcal septic shock (1 month to 18 years) included in this study received cefotaxime 100–150 mg/kg/day as antibiotic treatment. Left-over plasma samples were analyzed using LC-MS/MS to determine cefotaxime concentrations. MIC values from EUCAST were used to determine target attainment of cefotaxime for Neisseria meningitidis (0.125 mg/l), but also for Streptococcus pneumoniae (0.5 mg/l), Enterobacteriaceae (1 mg/l), and Staphylococcus aureus (4 mg/l). Target attainment was adequate when all samples exceeded MIC or fourfold MIC values. One thirty-six plasma samples of 37 severe septic shock patients were analyzed for cefotaxime concentrations. Median age was 2 years with a median PRISM-score of 24 and mortality of 24.8%. The median unbound cefotaxime concentration was 4.8 mg/l (range 0–48.7). Target attainment ranged from 94.6% for the MIC of N. meningitidis to 16.2% for fourfold the MIC S. aureus. Creatinine levels were significantly cor

Biosynthetic homeostasis and resilience of the complement system in health and infectious disease

Background: The complement system is a central component of the innate immune system. Constitutive biosynthesis of complement proteins is essential for homeostasis. Dysregulation as a consequence of genetic or environmental cues can lead to inflammatory syndromes or increased susceptibility to infection. However, very little is known about steady state levels in children or its kinetics during infection. Methods: With a newly developed multiplex mass spectrometry-based method we analyzed the levels of 32 complement proteins in healthy individuals and in a group of pediatric patients infected with bacterial or viral pathogens. Findings: In plasma from young infants we found reduced levels of C4BP, ficolin-3, factor B, classical pathway components C1QA, C1QB, C1QC, C1R, and terminal pathway components C5, C8, C9, as compared to healthy adults; whereas the majority of complement regulating (inhibito

Bacteremia in Childhood Life-Threatening Infections in Urban Gambia: EUCLIDS in West Africa

Background: The limited availability of microbiology services in sub-Saharan Africa impedes accurate diagnosis of bacterial pathogens and understanding of trends in prevalence and antibiotic sensitivities. We aimed to characterize bacteremia among hospitalized children in The Gambia and to identify factors associated with bacteremia and mortality. Methods: We prospectively studied children presenting wit

Mortality and morbidity in community-acquired sepsis in European pediatric intensive care units

Background: Sepsis is one of the main reasons for non-elective admission to pediatric intensive care units (PICUs), but little is known about determinants influencing outcome. We characterized children admitted with community-acquired sepsis to European PICUs and studied risk factors for mortality and disability. Methods: Data were collected within the collaborative Seventh Framework Programme (FP7)-funded EUCLIDS study, which is a prospective multicenter cohort study aiming to evaluate genetic determinants of susceptibility and/or severity in sepsis. This report includes 795 children admitted with community-acquired sepsis to 52 PICUs from seven European countries between July 2012 and January 2016. The primary outcome measure was in-hospital de

Identification of regulatory variants associated with genetic susceptibility to meningococcal disease

Non-coding genetic variants play an important role in driving susceptibility to complex diseases but their characterization remains challenging. Here, we employed a novel approach to interrogate the genetic risk of such polymorphisms in a more systematic way by targeting specific regulatory regions relevant for the phenotype studied. We applied this method to meningococcal disease susceptibility, using the DNA binding pattern of RELA - a NF-kB subunit, master regulator of the response to infection - under bacterial stimuli in nasopharyngeal epithelial cells. We designed a custom panel to cover these RELA binding sites and used it for targeted sequencing in cases and controls. Variant calling and association analysis were performed followed by validation of candidate polymorphisms by genotyping in three independent cohorts. We identified two new polymorphisms, rs4823231 and rs11913168, showing signs of association with meningococcal disease susceptibility. In addition, using our genomic data as well as publicly available resources, we found evidences for these SNPs to have potential regulatory effects on ATXN10 and LIF genes respectively. The variants and related candidate genes are relevant for infectious diseases and may have important contribution for meningococcal disease pathology. Finally, we described a novel genetic association approach that could be applied to other phenotypes