Genetics and genomics in pediatric septic shock

Guidance for assessment of the inflammation etiologic criterion for the GLIM diagnosis of malnutrition: A modified Delphi approach

BACKGROUND & AIMS

The Global Leadership Initiative on Malnutrition (GLIM) approach to malnutrition diagnosis is based on assessment of three phenotypic (weight loss, low body mass index, and reduced skeletal muscle mass) and two etiologic (reduced food intake/assimilation and disease burden/inflammation) criteria, with diagnosis confirmed by fulfillment of any combination of at least one phenotypic and at least one etiologic criterion. The original GLIM description provided limited guidance regarding assessment of inflammation and this has been a factor impeding further implementation of the GLIM criteria. We now seek to provide practical guidance for assessment of inflammation in support of the etiologic criterion for inflammation.

METHODS

A GLIM-constituted working group with 36 participants developed consensus-based guidance through a modified-Delphi review. A multi-round review and revision process served to develop seven guidance statements.

RESULTS

The final round of review was highly favorable with 99 % overall "agree" or "strongly agree" responses. The presence of acute or chronic disease, infection or injury that is usually associated with inflammatory activity may be used to fulfill the GLIM disease burden/inflammation criterion, without the need for laboratory confirmation. However, we recommend that recognition of underlying medical conditions commonly associated with inflammation be supported by C-reactive protein (CRP) measurements when the contribution of inflammatory components is uncertain. Interpretation of CRP requires that consideration be given to the method, reference values, and units (mg/dL or mg/L) for the clinical laboratory that is being used.

CONCLUSION

Confirmation of inflammation should be guided by clinical judgement based upon underlying diagnosis or condition, clinical signs, or CRP.

Association between vitamin D receptor gene variants and neonatal sepsis: A systematic review and meta-analysis

The objective of this systematic review and meta-analysis was elucidating the association of VDR SNPs (FokI, TaqI, BsmI, BgII, and ApaI) with neonatal sepsis. Literature search was performed to retrieve records published until August 2nd, 2023 (PROSPERO registration: CRD42023451355). Meta-analysis was carried out to determine the pooled estimates for Odds Ratio (OR). A total of four studies were included with 500 neonates (250 sepsis cases and 250 healthy controls). There was an association observed between TaqI SNP with neonatal sepsis for CT vs. CC+TT (OR=1.95) and TT vs CT+CC (OR=0.40). Moreover, the pooled estimates also suggested that CC vs. CT+TT (OR= 0.37) and C vs. T (OR=0.66) of FokI SNP were significantly associated with neonatal sepsis. SNP of BgII was found to be significantly associated with neonatal sepsis, but only reported in a single study.

Guidance for assessment of the inflammation etiologic criterion for the GLIM diagnosis of malnutrition: A modified Delphi approach

BACKGROUND

The Global Leadership Initiative on Malnutrition (GLIM) approach to malnutrition diagnosis is based on assessment of three phenotypic (weight loss, low body mass index, and reduced skeletal muscle mass) and two etiologic (reduced food intake/assimilation and disease burden/inflammation) criteria, with diagnosis confirmed by fulfillment of any combination of at least one phenotypic and at least one etiologic criterion. The original GLIM description provided limited guidance regarding assessment of inflammation, and this has been a factor impeding further implementation of the GLIM criteria. We now seek to provide practical guidance for assessment of inflammation.

METHODS

A GLIM-constituted working group with 36 participants developed consensus-based guidance through a modified Delphi review. A multiround review and revision process served to develop seven guidance statements.

RESULTS

The final round of review was highly favorable, with 99% overall "agree" or "strongly agree" responses. The presence of acute or chronic disease, infection, or injury that is usually associated with inflammatory activity may be used to fulfill the GLIM disease burden/inflammation criterion, without the need for laboratory confirmation. However, we recommend that recognition of underlying medical conditions commonly associated with inflammation be supported by C-reactive protein (CRP) measurements when the contribution of inflammatory components is uncertain. Interpretation of CRP requires that consideration be given to the method, reference values, and units (milligrams per deciliter or milligram per liter) for the clinical laboratory that is being used.

CONCLUSION

Confirmation of inflammation should be guided by clinical judgment based on underlying diagnosis or condition, clinical signs, or CRP.

A Genome-Wide Association Study of Serum Metabolite Profiles in Septic Shock Patients

OBJECTIVES

We sought to assess whether genetic associations with metabolite concentrations in septic shock patients could be used to identify pathways of potential importance for understanding sepsis pathophysiology.

DESIGN

Retrospective multicenter cohort studies of septic shock patients.

SETTING

All participants who were admitted to 27 participating hospital sites in three countries (Australia, New Zealand, and the United Kingdom) were eligible for inclusion.

PATIENTS

Adult, critically ill, mechanically ventilated patients with septic shock (n = 230) who were a subset of the Adjunctive Corticosteroid Treatment in Critically Ill Patients with Septic Shock trial (ClinicalTrials.gov number: NCT01448109).

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

A genome-wide association study was conducted for a range of serum metabolite levels for participants. Genome-wide significant associations (p ≤ 5 × 10-8) were found for the two major ketone bodies (3-hydroxybutyrate [rs2456680] and acetoacetate [rs2213037] and creatinine (rs6851961). One of these single-nucleotide polymorphisms (SNPs) (rs2213037) was located in the alcohol dehydrogenase cluster of genes, which code for enzymes related to the metabolism of acetoacetate and, therefore, presents a plausible association for this metabolite. None of the three SNPs showed strong associations with risk of sepsis, 28- or 90-day mortality, or Acute Physiology and Chronic Health Evaluation score (a measure of sepsis severity).

CONCLUSIONS

We suggest that the genetic associations with metabolites may reflect a starvation response rather than processes involved in sepsis pathophysiology. However, our results require further investigation and replication in both healthy and diseased cohorts including those of different ancestry.

Multilevel omics for the discovery of biomarkers in pediatric sepsis

Severe sepsis causes organ dysfunction and continues to be the leading reason for pediatric death worldwide. Early recognition of sepsis could substantially promote precision treatment and reduce the risk of pediatric death. The host cellular response to infection during sepsis between adults and pediatrics could be significantly different. A growing body of studies focused on finding markers in pediatric sepsis in recent years using multi-omics approaches. This narrative review summarized the progress in studying pediatric sepsis biomarkers from genome, transcript, protein, and metabolite levels according to the omics technique that has been applied for biomarker screening. It is most likely not a single biomarker could work for precision diagnosis of sepsis, but a panel of markers and probably a combination of markers detected at multi-levels. Importantly, we emphasize the importance of group distinction of infectious agents in sepsis patients for biomarker identification, because the host response to infection of bacteria, virus, or fungus could be substantially different and thus the results of biomarker screening. Further studies on the investigation of sepsis biomarkers that were caused by a specific group of infectious agents should be encouraged in the future, which will better improve the clinical execution of personalized medicine for pediatric sepsis.

Analysis and validation of diagnostic biomarkers and immune cell infiltration characteristics in pediatric sepsis by integrating bioinformatics and machine learning

BACKGROUND

Pediatric sepsis is a complicated condition characterized by life-threatening organ failure resulting from a dysregulated host response to infection in children. It is associated with high rates of morbidity and mortality, and rapid detection and administration of antimicrobials have been emphasized. The objective of this study was to evaluate the diagnostic biomarkers of pediatric sepsis and the function of immune cell infiltration in the development of this illness.

METHODS

Three gene expression datasets were available from the Gene Expression Omnibus collection. First, the differentially expressed genes (DEGs) were found with the use of the R program, and then gene set enrichment analysis was carried out. Subsequently, the DEGs were combined with the major module genes chosen using the weighted gene co-expression network. The hub genes were identified by the use of three machine-learning algorithms: random forest, support vector machine-recursive feature elimination, and least absolute shrinkage and selection operator. The receiver operating characteristic curve and nomogram model were used to verify the discrimination and efficacy of the hub genes. In addition, the inflammatory and immune status of pediatric sepsis was assessed using cell-type identification by estimating relative subsets of RNA transcripts (CIBERSORT). The relationship between the diagnostic markers and infiltrating immune cells was further studied.

RESULTS

Overall, after overlapping key module genes and DEGs, we detected 402 overlapping genes. As pediatric sepsis diagnostic indicators, CYSTM1 (AUC = 0.988), MMP8 (AUC = 0.973), and CD177 (AUC = 0.986) were investigated and demonstrated statistically significant differences (P < 0.05) and diagnostic efficacy in the validation set. As indicated by the immune cell infiltration analysis, multiple immune cells may be involved in the development of pediatric sepsis. Additionally, all diagnostic characteristics may correlate with immune cells to varying degrees.

CONCLUSIONS

The candidate hub genes (CD177, CYSTM1, and MMP8) were identified, and the nomogram was constructed for pediatric sepsis diagnosis. Our study could provide potential peripheral blood diagnostic candidate genes for pediatric sepsis patients.

Analysis of lactate metabolism-related genes and their association with immune infiltration in septic shock via bioinformatics method

Background: Lactate, as an essential clinical evaluation index of septic shock, is crucial in the incidence and progression of septic shock. This study aims to investigate the differential expression, regulatory relationship, clinical diagnostic efficacy, and immune infiltration of lactate metabolism-related genes (LMGs) in septic shock. Methods: Two sepsis shock datasets (GSE26440 and GSE131761) were screened from the GEO database, and the common differentially expressed genes (DEGs) of the two datasets were screened out. LMGs were selected from the GeneCards database, and lactate metabolism-related DEGs (LMDEGs) were determined by integrating DEGs and LMGs. Protein-protein interaction networks, mRNA-miRNA, mRNA-RBP, and mRNA-TF interaction networks were constructed using STRING, miRDB, ENCORI, and CHIPBase databases, respectively. Receiver operating characteristic (ROC) curves were constructed for each of the LMDEGs to evaluate the diagnostic efficacy of the expression changes in relation to septic shock. Finally, immune infiltration analysis was performed using ssGSEA and CIBERSORT. Results: This study identified 10 LMDEGs, including LDHB, STAT3, LDHA, GSR, FOXM1, PDP1, GCDH, GCKR, ABCC1, and CDKN3. Enrichment analysis revealed that DEGs were significantly enriched in pathways such as pyruvate metabolism, hypoxia pathway, and immune-inflammatory pathways. PPI networks based on LMDEGs, as well as 148 pairs of mRNA-miRNA interactions, 243 pairs of mRNA-RBP interactions, and 119 pairs of mRNA-TF interactions were established. ROC curves of eight LMDEGs (LDHA, GSR, STAT3, CDKN3, FOXM1, GCKR, PDP1, and LDHB) with consistent expression patterns in two datasets had an area under the curve (AUC) ranging from 0.662 to 0.889. The results of ssGSEA and CIBERSORT both showed significant differences in the infiltration of various immune cells, including CD8 T cells, T regulatory cells, and natural killer cells, and LMDEGs such as STAT3, LDHB, LDHA, PDP1, GSR, FOXM1, and CDKN3 were significantly associated with various immune cells. Conclusion: The LMDEGs are significantly associated with the immune-inflammatory response in septic shock and have a certain diagnostic accuracy for septic shock.

Biomarker-based risk model to predict persistent multiple organ dysfunctions after congenital heart surgery: a prospective observational cohort study

BACKGROUND

Multiple organ dysfunction syndrome (MODS) is an important cause of post-operative morbidity and mortality for children undergoing cardiac surgery requiring cardiopulmonary bypass (CPB). Dysregulated inflammation is widely regarded as a key contributor to bypass-related MODS pathobiology, with considerable overlap of pathways associated with septic shock. The pediatric sepsis biomarker risk model (PERSEVERE) is comprised of seven protein biomarkers of inflammation and reliably predicts baseline risk of mortality and organ dysfunction among critically ill children with septic shock. We aimed to determine if PERSEVERE biomarkers and clinical data could be combined to derive a new model to assess the risk of persistent CPB-related MODS in the early post-operative period.

METHODS

This study included 306 patients < 18 years old admitted to a pediatric cardiac ICU after surgery requiring cardiopulmonary bypass (CPB) for congenital heart disease. Persistent MODS, defined as dysfunction of two or more organ systems on postoperative day 5, was the primary outcome. PERSEVERE biomarkers were collected 4 and 12 h after CPB. Classification and regression tree methodology were used to derive a model to assess the risk of persistent MODS.

RESULTS

The optimal model containing interleukin-8 (IL-8), chemokine ligand 3 (CCL3), and age as predictor variables had an area under the receiver operating characteristic curve (AUROC) of 0.86 (0.81-0.91) for differentiating those with or without persistent MODS and a negative predictive value of 99% (95-100). Ten-fold cross-validation of the model yielded a corrected AUROC of 0.75 (0.68-0.84).

CONCLUSIONS

We present a novel risk prediction model to assess the risk for development of multiple organ dysfunction after pediatric cardiac surgery requiring CPB. Pending prospective validation, our model may facilitate identification of a high-risk cohort to direct interventions and studies aimed at improving outcomes via mitigation of post-operative organ dysfunction.

Biomarker-based risk model to predict persistent multiple organ dysfunctions after congenital heart surgery â€" A prospective observational cohort study

Background: Multiple organ dysfunction syndrome (MODS) is an important cause of post-operative morbidity and mortality for children undergoing cardiac surgery requiring cardiopulmonary bypass (CPB). Dysregulated inflammation is widely regarded as a key contributor to bypass-related MODS pathobiology, with considerable overlap of pathways associated with septic shock. The pediatric sepsis biomarker risk model (PERSEVERE) is comprised of seven protein biomarkers of inflammation, and reliably predicts baseline risk of mortality and organ dysfunction among critically ill children with septic shock. We aimed to determine if PERSEVERE biomarkers and clinical data could be combined to derive a new model to assess the risk of persistent CPB-related MODS in the early post-operative period. Methods: This study included 306 patients <18 years old admitted to a pediatric cardiac ICU after surgery requiring cardiopulmonary bypass (CPB) for congenital heart disease. Persistent MODS, defined as dysfunction of two or more organ systems on postoperative day 5, was the primary outcome. PERSEVERE biomarkers were collected 4 and 12 hours after CPB. Classification and Regression Tree methodology was used to derive a model to assess the risk of persistent MODS. Results: The optimal model containing interleukin-8 (IL-8), chemokine ligand 3 (CCL3), and age as predictor variables, had an area under the receiver operating characteristic curve (AUROC) of 0.86 (0.81-0.91) for differentiating those with or without persistent MODS, and a negative predictive value of 99% (95-100). Ten-fold cross-validation of the model yielded a corrected AUROC of 0.75. Conclusions: We present a novel risk prediction model to assess the risk for development of multiple organ dysfunction after pediatric cardiac surgery requiring CPB. Pending prospective validation, our model may facilitate identification of a high-risk cohort to direct interventions and studies aimed at improving outcomes via mitigation of post-operative organ dysfunction. Clinical Trial Registration Number: This study does not meet criteria for a clinical trial per the WHO International Clinical Trials Registry Platform as no intervention was performed.

Association between Interleukin-6 rs1800795 Polymorphism and Serum Interleukin-6 Levels and Full-Term Neonatal Sepsis

Objective Cytokines are involved in the pathogenesis of sepsis. Association between IL-6 rs1800795 G/C polymorphism and the risks of sepsis is controversial. The aim of this study was to investigate the association of IL-6 rs1800795 G/C gene polymorphism with full-term neonatal sepsis and to determine its effect on the serum IL6 levels in these infants by a prospective study.

Methods The study included 200 full-term neonates from January 2019 to December 2020: 100 with sepsis (sepsis group), 47 with culture proven sepsis, and 53 with clinical sepsis, and 100 without infection (control group). The concentrations of IL-6 in serum were determined using enzyme-linked immunosorbent assay (ELISA). The polymorphisms of IL-6 rs1800795 G/C were analyzed to compare the genotypic and allelic frequencies in the groups by using the first-generation sequencing (Sanger sequencing). The association was studied between IL-6 rs1800795 G/C polymorphisms and serum IL-6 levels, and neonatal sepsis. The relationships between IL-6 rs1800795G/C polymorphisms and sepsis and serum IL-6 levels were separately analyzed by logistic regression and analysis of variance.

Results There were no significant differences in genotypic frequencies and allelic frequencies of IL-6 rs1800795(G/C) in the groups (p >0.05). There were no relations between IL-6 rs1800795G/C polymorphisms and sepsis and serum IL-6 levels by statistical analysis (p >0.05).

Conclusion IL-6rs1800795G/C may not be genetic risk factors for full-term neonates; There was no association between serum IL-6 levels and IL-6 rs1800795G/C polymorphisms.

Candidate Biomarkers for the Detection of Serious Infections in Children: A Prospective Clinical Study

Serious bacterial infections (SBI) in children are associated with considerable morbidity and mortality, and their early identification remains challenging. The role of laboratory tests in this setting is still debated, and new biomarkers are needed. This prospective, observational, single-center study aims to evaluate the diagnostic role of blood biomarkers in detecting SBI in children presenting with signs of systemic inflammatory response syndrome (SIRS). A panel of biomarkers was performed, including C-reactive protein (CRP), procalcitonin (PCT), white blood cell count (WBC), absolute neutrophil count (ANC), interleukin (IL)-6, IL-8, IL-10, human terminal complement complex (C5b-9), Plasmalemma-Vesicle-associated protein 1 (PV-1), Intercellular Adhesion Molecule-1 (ICAM-1), and Phospholipase A2 (PLA2). Among 103 patients (median age 2.9 years, 60% males), 39 had a diagnosis of SBI (38%). Significant predictors of SBI were CRP (p = 0.001) and ICAM-1 (p = 0.043). WBC (p = 0.035), ANC (p = 0.012) and ANC/WBC ratio (p = 0.015) were also significantly associated with SBI in children without pre-existing neutropenia. ROC curves, however, revealed suboptimal performance for all variables. Nevertheless, a model that combined CRP and ANC/WBC ratio had more in-depth diagnostic accuracy than either of the two variables. Overall, this study confirms the limited usefulness of blood biomarkers for the early diagnosis of SBI. WBC, ANC, ANC/WBC ratio, CRP, and ICAM-1 showed the best, albeit moderate, diagnostic accuracy.

Impact of Inherited Genetic Variants on Critically Ill Septic Children

Sepsis remains an important source of morbidity and mortality in children, despite the development of standardized care. In the last decades, there has been an increased interest in genetic and genomic approaches to early recognition and development of treatments to manipulate the host inflammatory response. This review will present a summary of the normal host response to infection and progression to sepsis, followed by highlighting studies with a focus on gene association studies, epigenetics, and genome-wide expression profiling. The susceptibility (or outcome) of sepsis in children has been associated with several polymorphisms of genes broadly involved in inflammation, immunity, and coagulation. More recently, gene expression profiling has been focused on identifying novel biomarkers, pathways and therapeutic targets, and gene expression-based subclassification. Knowledge of a patient’s individual genotype may, in the not-too-remote future, be used to guide tailored treatment for sepsis. However, at present, the impact of genomics remains far from the bedside of critically ill children.

Endothelial Damage in Sepsis: The Importance of Systems Biology

The early diagnosis and appropriate stratification of sepsis continues to be one of the most important challenges in modern medicine. Single isolated biomarkers have not been enough to improve diagnostic and prognostic strategies and to progress toward therapeutic goals. The information generated by the human genome project has allowed a more holistic approach to the problem. The integration of genomics, transcriptomics, proteomics and metabolomics in sepsis has allowed us to progress in the knowledge of new pathways which are pathophysiologically involved in this disease. Thus, we have understood the importance of and complex interaction between the inflammatory response and the endothelium. Understanding the role of important parts of the microcirculation, such as the endothelial glycocalyx and its interaction with the inflammatory response, has provided early recognition elements for clinical practice that allow the rational use of traditional medical interventions in sepsis. This comprehensive approach, which differs from the classical mechanistic approach, uses systems biology to increase the diagnostic and prognostic spectrum of endothelial damage biomarkers in sepsis, and to provide information on new pathways involved in the pathophysiology of the disease. This, in turn, provides tools for perfecting traditional medical interventions, using them at the appropriate times according to the disease's pathophysiological context, while at the same time discovering new and improved therapeutic alternatives. We have the challenge of transferring this ideal scenario to our daily clinical practice to improve our patients' care. The purpose of this article is to provide a general description of the importance of systems biology in integrating the complex interaction between the endothelium and the inflammatory response in sepsis.

The horizon of pediatric cardiac critical care

Pediatric Cardiac Critical Care (PCCC) is a challenging discipline where decisions require a high degree of preparation and clinical expertise. In the modern era, outcomes of neonates and children with congenital heart defects have dramatically improved, largely by transformative technologies and an expanding collection of pharmacotherapies. Exponential advances in science and technology are occurring at a breathtaking rate, and applying these advances to the PCCC patient is essential to further advancing the science and practice of the field. In this article, we identified and elaborate on seven key elements within the PCCC that will pave the way for the future.

Meningococcus, this famous unknown

Neisseria meningitidis (meningococcus) is a Gram-negative bacterium responsible for two devastating forms of invasive diseases: purpura fulminans and meningitis. Since the first description of the epidemic nature of the illness at the dawn of the nineteenth century, the scientific knowledge of meningococcal infection has increased greatly. Major advances have been made in the management of the disease with the advent of antimicrobial therapy and the implementation of meningococcal vaccines. More recently, an extensive knowledge has been accumulated on meningococcal interaction with its human host, revealing key processes involved in disease progression and new promising therapeutic approaches.

Adenoviral Respiratory Infection-Associated Mortality in Children: A Retrospective Case Series

Viral respiratory infections are a leading cause of illness and hospitalization in young children worldwide. Case fatality rates in pediatric patients with adenoviral lower respiratory tract infection requiring intensive care unit (ICU) admission have been reported between 7 and 22%. We investigated the demographics and clinical characteristics in pediatric mortalities associated with adenoviral respiratory infection at 12 academic children's hospitals in the United States. There were 107 mortality cases included in our study, 73% of which had a chronic medical condition. The most common chronic medical condition was immunocompromised state in 37 cases (35%). The incidences of pediatric acute respiratory distress syndrome (78%) and multiple organ dysfunction syndrome (94%) were profound. Immunocompetent cases were more likely to receive mechanical ventilation within the first hour of ICU admission (60 vs. 14%, p < 0.001) and extracorporeal membrane oxygenation (27 vs. 5%, p = 0.009), and less likely to receive continuous renal replacement therapy (20 vs. 49%, p = 0.002) or have renal dysfunction (54 vs. 78%, p = 0.014) as compared with immunocompromised cases. Immunocompromised cases were more likely to have bacteremia (57 vs. 16%, p < 0.001) and adenoviremia (51 vs. 17%, p < 0.001) and be treated with antiviral medications (81 vs. 26%, p < 0.001). We observed a high burden of nonrespiratory organ system dysfunction in a cohort of pediatric case fatalities with adenoviral respiratory infection. The majority of cases had a chronic medical condition associated with an increased risk of complications from viral respiratory illness, most notably immunocompromised state. Important treatment differences were noted between immunocompromised and immunocompetent cases.

Biomarkers in pediatric sepsis: a review of recent literature

Sepsis remains the leading cause of death in infants and children worldwide. Prompt diagnosis and monitoring of infection is pivotal to guide therapy and optimize outcomes. No single biomarker has so far been identified to accurately diagnose sepsis, monitor response and predict severity. We aimed to assess existing evidence of available sepsis biomarkers, and their utility in pediatric population. C-reactive protein and procalcitonin remain the most extensively evaluated and used biomarkers. However, biomarkers related to endothelial damage, vasodilation, oxidative stress, cytokines/chemokines and cell bioproducts have also been identified, often with regard to the site of infection and etiologic pathogen; still, with controversial utility. A multi-biomarker model driven by genomic tools could establish a personalized approach in future disease management.

Quality Control Measures and Validation in Gene Association Studies: Lessons for Acute Illness

Acute illness is a complex constellation of responses involving dysregulated inflammatory and immune responses, which are ultimately associated with multiple organ dysfunction. Gene association studies have associated single-nucleotide polymorphisms (SNPs) with clinical and pharmacological outcomes in a variety of disease states, including acute illness. With approximately 4 to 5 million SNPs in the human genome and recent studies suggesting that a large portion of SNP studies are not reproducible, we suggest that the ultimate clinical utility of SNPs in acute illness depends on validation and quality control measures. To investigate this issue, in December 2018 and January 2019 we searched the literature for peer-reviewed studies reporting data on associations between SNPs and clinical outcomes and between SNPs and pharmaceuticals (i.e., pharmacogenomics) published between January 2011 to February 2019. We review key methodologies and results from a variety of clinical and pharmacological gene association studies, including trauma and sepsis studies, as illustrative examples on current SNP association studies. In this review article, we have found three key points which strengthen the potential accuracy of SNP association studies in acute illness and other diseases: providing evidence of following a protocol quality control method such as the one in Nature Protocols or the OncoArray QC Guidelines; enrolling enough patients to have large cohort groups; and validating the SNPs using an independent technique such as a second study using the same SNPs with new patient cohorts. Our survey suggests the need to standardize validation methods and SNP quality control measures in medicine in general, and specifically in the context of complex disease states such as acute illness.

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.

The History of Biomarkers: How Far Have We Come?

Sepsis is one of the oldest and most elusive syndromes in medicine that is still incompletely understood. Biomarkers may help to transform sepsis from a physiologic syndrome to a group of distinct biochemical disorders. This will help to differentiate between systemic inflammation of infectious and noninfectious origin and aid therapeutic decision making, hence improve the prognosis for patients, guide antimicrobial therapy, and foster the development of novel adjunctive sepsis therapies. To reach this goal requires increased systematic investigation that includes twenty-first century scientific approaches and technologies and appropriate clinical evaluation.

Glucocorticosteroids for sepsis in children. A protocol for a systematic review

BACKGROUND

Sepsis is the primary diagnosis in more than 8% of all critically ill children and sepsis is among the ten leading causes of death in children <10 years. Glucocorticosteroids are currently recommended in septic children with fluid or catecholamine resistant refractory shock. Glucocorticosteroids are widely used for severe sepsis in paediatric intensive care units worldwide. However, the evidence on the clinical effects of glucocorticosteroids for sepsis in children is unclear.

METHODS

We will perform a systematic review with meta-analysis and Trial Sequential Analysis of randomised clinical trials. We will include randomised clinical trials assessing the effects of glucocorticosteroids vs placebo or no intervention as an add-on therapy to standard care for sepsis in children. For the assessment of harms, we will also include quasi-randomised studies and observational studies identified during our searches for randomised clinical trials.

DISCUSSION

This review will seek to assess whether glucocorticosteroids indeed have their therapeutic place in the standard treatment for sepsis in children.

Precision medicine in pediatric sepsis

PURPOSE OF REVIEW

Pediatric sepsis is a heterogeneous state associated with significant morbidity and mortality, but treatment strategies are limited. Clinical trials of immunomodulators in sepsis have shown no benefit, despite having a strong biological rationale. There is considerable interest in application of a precision medicine approach to pediatric sepsis to identify patients who are more likely to benefit from targeted therapeutic interventions.

RECENT FINDINGS

Precision medicine requires a clear understanding of the molecular basis of disease. 'Omics data' and bioinformatics tools have enabled identification of endotypes of pediatric septic shock, with corresponding biological pathways. Further, using a multibiomarker-based approach, patients at highest risk of poor outcomes can be identified at disease onset. Enrichment strategies, both predictive and prognostic, may be used to optimize patient selection in clinical trials and identify a subpopulation in whom therapy of interest may be trialed. A bedside-to-bench-to-bedside model may offer clinicians pragmatic tools to aid in decision-making.

SUMMARY

Precision medicine approaches may be used to subclassify, risk-stratify, and select pediatric patients with sepsis who may benefit from new therapies. Application of precision medicine will require robust basic and translational research, rigorous clinical trials, and infrastructure to collect and analyze big data.

The Pediatric Sepsis Biomarker Risk Model (PERSEVERE) Biomarkers Predict Clinical Deterioration and Mortality in Immunocompromised Children Evaluated for Infection

Pediatric sepsis and bacterial infection cause significant morbidity and mortality worldwide, with immunocompromised patients being at particularly high risk of rapid deterioration and death. This study evaluated if PERSEVERE, PERSEVERE-II, or the PERSEVERE biomarkers, can reliably estimate the risk of clinical deterioration and 28-day mortality among immunocompromised pediatric patients. This is a single-center prospective cohort study conducted from July 2016 through September 2017 incorporating 400 episodes of suspected bacterial infection from the inpatient units at Cincinnati Children’s Hospital Medical Center, a large, tertiary care children’s hospital. The primary analysis assessed clinical deterioration within 72 hours of evaluation for infection. Secondarily, we assessed 28-day mortality. Clinical deterioration was seen in 15% of subjects. Twenty-eight day mortality was 5%, but significantly higher among critically ill patients. Neither PERSEVERE nor PERSEVERE-II performed well to predict clinical deterioration or 28-day mortality, thus we derived new stratification models using the PERSEVERE biomarkers with both high sensitivity and negative predictive value. In conclusion, we evaluated previously validated biomarker risk models in a novel population of largely non-critically ill immunocompromised pediatric patients, and attempted to stratify patients based on a new outcome metric, clinical deterioration. The new highly predictive models indicate common physiologic pathways to clinical deterioration or death from bacterial infection.

LINCS L1000 dataset-based repositioning of CGP-60474 as a highly potent anti-endotoxemic agent

Sepsis is one of the most common clinical syndromes that causes death and disability. Although many studies have developed drugs for sepsis treatment, none have decreased the mortality rate. The aim of this study was to identify a novel treatment option for sepsis using the library of integrated network-based cellular signatures (LINCS) L1000 perturbation dataset based on an in vitro and in vivo sepsis model. Sepsis-related microarray studies of early-stage inflammatory processes in patients and innate immune cells were collected from the Gene Expression Omnibus (GEO) data repository and used for candidate drug selection based on the LINCS L1000 perturbation dataset. The anti-inflammatory effects of the selected candidate drugs were analyzed using activated macrophage cell lines. CGP-60474, an inhibitor of cyclin-dependent kinase, was the most potent drug. It alleviated tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) in activated macrophages by downregulating the NF-κB activity, and it reduced the mortality rate in LPS induced endotoxemia mice. This study shows that CGP-60474 could be a potential therapeutic candidate to attenuate the endotoxemic process. Additionally, the virtual screening strategy using the LINCS L1000 perturbation dataset could be a cost and time effective tool in the early stages of drug development.

Fluid Bolus Therapy in Pediatric Sepsis: Current Knowledge and Future Direction

Sepsis is a leading cause of morbidity and mortality in children with a worldwide prevalence in pediatric intensive care units of approximately 8%. Fluid bolus therapy (FBT) is a first line therapy for resuscitation of septic shock and has been a recommendation of international guidelines for nearly two decades. The evidence base supporting these guidelines are based on limited data including animal studies and case control studies. In recent times, evidence suggesting harm from fluid in terms of morbidity and mortality have generated interest in evaluating FBT. In view of this, studies of fluid restrictive strategies in adults and children have emerged. The complexity of studying FBT relates to several points. Firstly, the physiological and haemodynamic response to FBT including magnitude and duration is not well described in children. Secondly, assessment of the circulation is based on non-specific clinical signs and limited haemodynamic monitoring with limited physiological targets. Thirdly, FBT exists in a complex myriad of pathophysiological responses to sepsis and other confounding therapies. Despite this, a greater understanding of the role of FBT in terms of the physiological response and possible harm is warranted. This review outlines current knowledge and future direction for FBT in sepsis.

Clinical relevance of peroxisome proliferator-activated receptor-γ gene polymorphisms with sepsis

BACKGROUND

Peroxisome proliferator-activated receptor-γ (PPARγ) is a regulator of inflammation. This study aimed to explore associations between PPARγ gene single-nucleotide polymorphisms (SNPs) and susceptibility to and clinical outcome of sepsis in the North China Han population.

METHODS

This study included 303 patients with sepsis and 303 controls. We conducted genetic typing for 13 common PPARγ gene SNPs (improved multiplex ligation detection reaction), linkage disequilibrium mapping, and haplotype inference. Associations between SNP genotypes/haplotypes and sepsis susceptibility and outcome (septic shock, organ dysfunction, or death) were assessed using unconditional logistic regression analysis.

RESULTS

For rs2972164, patients with genotypes CT/CT+TT had higher risk of sepsis than genotype CC (odds ratio [95% CI]: 1.74 [1.05-2.86], P = .03 and 1.72 [1.06-2.80], P = .026, respectively); the T allele was associated with increased sepsis risk compared with the C allele (1.64 [1.04-2.58], P = .033). For rs1801282, genotypes CG/CG+GG had lower risk of sepsis than genotype CC (0.55 [0.33-0.92], P = .024 and 0.57 [0.35-0.95], P = .03, respectively); the G allele was associated with decreased sepsis risk compared with the C allele (0.62 [0.39-1.01], P = .055). For rs4135275, genotypes AG/AG+GG had higher risk of severe organ dysfunction (multiple organ dysfunction syndrome score >8) than genotype AA (2.66 [1.16-6.09], P = .038 and 2.21 [1.00-4.85], P = .042, respectively). Haplotype TAT (rs2972164, rs4684846, and rs17036188) was associated with increased sepsis risk (1.66 [1.03-2.67], P = .038).

CONCLUSIONS

No mutation was correlated with septic shock or death. PPARγ gene polymorphisms may play a role in the occurrence and progression of sepsis in the North China Han population.

Sepsis and septic shock: Pathogenesis and treatment perspectives

The majority of bacteremias do not develop to sepsis: bacteria are cleared from the bloodstream. Oxygen released from erythrocytes and humoral immunity kill bacteria in the bloodstream. Sepsis develops if bacteria are resistant to oxidation and proliferate in erythrocytes. Bacteria provoke oxygen release from erythrocytes to arterial blood. Abundant release of oxygen to the plasma triggers a cascade of events that cause: 1. oxygen delivery failure to cells; 2. oxidation of plasma components that impairs humoral regulation and inactivates immune complexes; 3. disseminated intravascular coagulation and multiple organs' failure. Bacterial reservoir inside erythrocytes provides the long-term survival of bacteria and is the cause of ineffectiveness of antibiotics and host immune reactions. Treatment perspectives that include different aspects of sepsis development are discussed.

Tumor necrosis factor-α -308G/A and -238G/A polymorphisms are associated with increased risks of sepsis: evidence from an updated meta-analysis

Previous studies have reported the relationship between tumor necrosis factor-α (TNF-α) -308G/A and -238G/A polymorphisms and sepsis risk with inconsistent results. The aim of this study was to estimate the association of the two polymorphisms with risk of sepsis or sepsis-related mortality using a meta-analysis. PubMed, Embase, and Web of Science databases were searched up to June 20 2016. Pooled odds ratios (ORs) and 95% confidence intervals (CIs) were calculated using fixed or random effect model. Twenty-six studies were included in this meta-analysis. Overall, an increased sepsis risk of TNF-α -308G/A was observed (GA vs GG: OR = 1.43, 95% CI: 1.07-1.92; GA/AA vs GG: OR = 1.42, 95% CI: 1.06-1.89). Subgroup analyses showed that the significant association was found in Asians (GA vs GG: OR = 1.63, 95% CI: 1.01-2.63) and adult patients. Similarly, an increased sepsis risk of TNF-α -238G/A was observed in overall and subgroup analyses. However, no significant association was found between TNF-α -308G/A and -238G/A polymorphisms and sepsis-related mortality. These findings indicate that both TNF-α -308G/A and -238G/A polymorphisms were associated with increased risks of sepsis but not sepsis-related mortality. Further studies with larger sample size are needed to confirm these results.

The Relevance of Coding Gene Polymorphysms of Cytokines and Cellular Receptors in Sepsis

Sepsis is an injurious systemic host response to infection, which can often lead to septic shock and death. Recently, the immune-pathogenesis and genomics of sepsis have become a research topic focusing on the establishment of diagnostic and prognostic biomarkers. As yet, none have been identified as having the necessary specificity to be used independently of other factors in this respect. However the accumulation of current evidence regarding genetic variations, especially the single nucleotide polymorphisms (SNPs) of cytokines and other innate immunity determinants, partially explains the susceptibility and individual differences of patients with regard to the evolution of sepsis. This article outlines the role of genetic variation of some serum proteins which have the potential to be used as biomarker values in evaluating sepsis susceptibility and the progression of the condition.

A journey into the brain: insight into how bacterial pathogens cross blood-brain barriers

The blood-brain barrier, which is one of the tightest barriers in the body, protects the brain from insults, such as infections. Indeed, only a few of the numerous blood-borne bacteria can cross the blood-brain barrier to cause meningitis. In this Review, we focus on invasive extracellular pathogens, such as Neisseria meningitidis, Streptococcus pneumoniae, group B Streptococcus and Escherichia coli, to review the obstacles that bacteria have to overcome in order to invade the meninges from the bloodstream, and the specific skills they have developed to bypass the blood-brain barrier. The medical importance of understanding how these barriers can be circumvented is underlined by the fact that we need to improve drug delivery into the brain.

Research Advances in Biomarker for Sepsis

Sepsis is one of the most common causes of death in severely injured patients worldwide. The early detection of sepsis still has to be solved in clinical practice. The delayed diagnosis often contributes to inappropriate antimicrobial treatment and subsequent high mortality. Sepsis biomarkers are produced during the host response to infection. Traditional biomarkers are polypeptides and/or proteins derived from this response. Omics-based biomarkers are screening out from all kinds of molecules of host response while high-throughout omics technologies are emerging. This review describes traditional and potential omics-based sepsis biomarkers from currently available literatures. The combination of these biomarkers would refine the identification of sepsis for further clinical and experimental sepsis studies.

Pharmacogenomics and pharmacogenetics for the intensive care unit: a narrative review

PURPOSE

Knowledge of how alterations in pharmacogenomics and pharmacogenetics may affect drug therapy in the intensive care unit (ICU) has received little study. We review the clinically relevant application of pharmacogenetics and pharmacogenomics to drugs and conditions encountered in the ICU.

SOURCE

We selected relevant literature to illustrate the important concepts contained within.

PRINCIPAL FINDINGS

Two main approaches have been used to identify genetic abnormalities - the candidate gene approach and the genome-wide approach. Genetic variability in response to drugs may occur as a result of alterations of drug-metabolizing (cytochrome P [CYP]) enzymes, receptors, and transport proteins leading to enhancement or delay in the therapeutic response. Of relevance to the ICU, genetic variation in CYP-450 isoenzymes results in altered effects of midazolam, fentanyl, morphine, codeine, phenytoin, clopidogrel, warfarin, carvedilol, metoprolol, HMG-CoA reductase inhibitors, calcineurin inhibitors, non-steroidal anti-inflammatory agents, proton pump inhibitors, and ondansetron. Changes in cholinesterase enzyme function may affect the disposition of succinylcholine, benzylisoquinoline muscle relaxants, remifentanil, and hydralazine. Genetic variation in transport proteins leads to differences in the response to opioids and clopidogrel. Polymorphisms in drug receptors result in altered effects of β-blockers, catecholamines, antipsychotic agents, and opioids. Genetic variation also contributes to the diversity and incidence of diseases and conditions such as sepsis, malignant hyperthermia, drug-induced hypersensitivity reactions, cardiac channelopathies, thromboembolic disease, and congestive heart failure.

CONCLUSION

Application of pharmacogenetics and pharmacogenomics has seen improvements in drug therapy. Ongoing study and incorporation of these concepts into clinical decision making in the ICU has the potential to affect patient outcomes.

Emerging infection and sepsis biomarkers: will they change current therapies?

INTRODUCTION

Sepsis is a heterogeneous syndrome characterized by both immune hyperactivity and relative immune suppression. Biomarkers have the potential to improve recognition and management of sepsis through three main applications: diagnosis, monitoring response to treatment, and stratifying patients based on prognosis or underlying biological response.

AREAS COVERED

This review focuses on specific examples of well-studied, evidence-supported biomarkers, and discusses their role in clinical practice with special attention to antibiotic stewardship and cost-effectiveness. Biomarkers were selected based on availability of robust prospective trials and meta-analyses which supported their role as emerging tools to improve the clinical management of sepsis. Expert commentary: Great strides have been made in candidate sepsis biomarker discovery and testing, with the biomarkers in this review showing promise. Yet sepsis remains a dynamic illness with a great degree of biological heterogeneity - heterogeneity which may be further resolved by recently discovered gene expression-based endotypes in septic shock.

Critical cardiac care in children: looking backward and looking forward

The growth of Pediatric Cardiovascular Intensive Care as a subspecialty has been incredible. Outcomes have improved, care delivery has matured, and research has made advances. Within this review, we take the opportunity to examine the subspecialty's past accomplishments with pride, take stock in its current state, and look forward with excitement to its future. While outcomes in general have improved dramatically, we must always be aware of the outcomes that matter to families and patients. Additionally, we must constantly ask ourselves to improve. Research into neuroprotection and individual therapeutic strategies based in genomic medicine provide the next opportunity for the subspecialty to improve.

Genetic and epigenetic factors in the regulation of the immune response

PURPOSE OF REVIEW

The review will update readers on research examining the influence of genetic variation and epigenetics on the immune system and whether genetic variation influences the outcome of critically ill children.

RECENT FINDINGS

Although there have been few recent studies examining the role of genetic variation in the severity of disease or outcome in critically ill children, studies in critically ill adults have been informative. For example, genetic variations in the genes coding for various components of the immune response, such as the Toll-like receptor 1, interleukin-1RA, proprotein convertase subtilisin/kexin type 9, adoponectin, nuclear factor erythroid 2-related factor 2, elafin, sphingosine 1-phosphate receptor 3, and sushi, von Willebrand factor type A, EGF and pentraxin domain containing 1 have been associated with various outcomes in critically ill adult populations. Many of the variants demonstrate functional consequences in the protein levels or activities. In critically ill children, there is an association with increased ICU length of stay in children with septic shock with one of the Toll-like receptor 1 variants.

SUMMARY

The degree of influence of host genetic variation in the outcome in critically ill children remains a much understudied area of research. However, it remains important because it may not only help identify children at risk for worse outcomes but it may provide insight into mechanisms of critical illnesses and novel therapies.

Dynamic expression of leukocyte innate immune genes in whole blood from horses with lipopolysaccharide-induced acute systemic inflammation

Background

In horses, insights into the innate immune processes in acute systemic inflammation are limited even though these processes may be highly important for future diagnostic and therapeutic advances in high-mortality disease conditions as the systemic inflammatory response syndrome (SIRS) and sepsis. Therefore, the aim of this study was to investigate the expression of 31 selected blood leukocyte immune genes in an equine model of acute systemic inflammation to identify significantly regulated genes and to describe their expression dynamics during a 24-h experimental period. Systemic inflammation was induced in 6 adult horses by the intravenous injection of 1 μg lipopolysaccharide (LPS) per kg btw. Sixteen blood samples were collected for each horse at predetermined intervals and analyzed by reverse transcription quantitative real-time PCR. Post-induction expression levels for each gene were compared with baseline levels.

Results

Systemic inflammation was confirmed by the presence of clinical and hematological changes which were consistent with SIRS. The clinical response to LPS was transient and brief as all horses except one showed unaltered general demeanor after 24 h. Twenty-two leukocyte genes were significantly regulated at at least one time point during the experimental period. By close inspection of the temporal responses the dynamic changes in mRNA abundance revealed a very rapid onset of both pro- and anti-inflammatory mediators and a substantial variation in both expression magnitudes and duration of changes between genes. A majority of the 22 significantly regulated genes peaked within the first 8 h after induction, and an on-going, albeit tightly controlled, regulation was seen after 24 h despite approximate clinical recovery.

Conclusions

This first broad study of gene expressions in blood leukocytes during equine acute LPS-induced systemic inflammation thoroughly characterized a highly regulated and dynamic innate immune response. These results provide new insights into the molecular mechanisms of equine systemic inflammation.

Electronic supplementary material

The online version of this article (doi:10.1186/s12917-015-0450-5) contains supplementary material, which is available to authorized users.

The 4G/4G Genotype of PAI-1 Polymorphism Is Associated with Higher Plasma PAI-1 Concentrations and Mortality in Patients with Severe Sepsis

Objective

Two studies have reported that patients with the 4G/4G genotype of the plasminogen activator inhibitor-1 (PAI-1) genetic polymorphism had higher plasma PAI-1 concentrations and higher risk of death than those with the 4G/5G or 5G/5G genotypes; one study involved 175 children with meningococcal disease, and the other included 88 adult patients with septic shock. Thus, the objective of this study was to determine whether there is an association between carriage of the 4G/4G genotype, plasma PAI-1 concentrations and mortality in a large series of adult septic patients.

Methods

An observational, prospective, multicenter study was carried out in six Spanish Intensive Care Units including severe septic patients. We determined the PAI-1 4G/5G polymorphism and plasma PAI-1 concentrations in all patients. The end-points of the study were 30-day and 6-month mortality.

Results

We included a total of 260 patients, 82 (31.5%) with 4G/4G, 126 (48.5%) with 4G/5G and 52 (20.0%) with 5G/5G genotype. Multivariate logistic regression analysis showed that the 4G/4G genotype was associated with higher mortality at 30 days (Odds Ratio = 1.95; 95% CI = 1.063–3.561; p = 0.03) and at 6 months (Odds Ratio = 2.19; 95% CI = 1.221–3.934; p = 0.01), and that higher plasma PAI-1 concentrations were associated with higher mortality at 30 days (Odds Ratio = 1.01; 95% CI = 1.002–1.022; p = 0.02) at 6 months (Odds Ratio = 1.01; 95% CI = 1.003–1.023; p = 0.01). Multivariate linear regression analysis showed that increased plasma PAI-1 concentrations were associated with the PAI-1 4G/4G genotype (regression coefficient = 4.82; 95% CI = 3.227 to 6.406; p<0.001).

Conclusions

The major findings of our study, to our knowledge the largest series reporting data about 4G/5G polymorphism of the PAI-1 gene, plasma PAI-1 concentrations and mortality in septic patients, were that septic patients with the 4G/4G genotype had higher plasma PAI-1 concentrations and higher risk of death than those with 4G/5G or 5G/5G genotypes.

Neonatal infections in Saudi Arabia: Association with cytokine gene polymorphisms

In recent years, many studies have reported potential associations between cytokine gene polymorphisms and the development, course, and outcome of sepsis, often with apparently conflicting results. The objective of this study was to investigate single nucleotide polymorphism (SNP) in the interleukin (IL)-1β –31 T/C, IL-6 –174 G/C, tumor necrosis factor α (TNF-α) –308 G/A, and interferon γ (IFN-γ) +874 A/T genes for their possible association with susceptibility to early onset sepsis (EOS) in Saudi newborn infants. A total of 205 newborn infants aged 1-2 days were consecutively enrolled onto the study having met the inclusion criteria (as per the research protocol). DNA was extracted from filter papers using the Chelex-100 method. The cytokines SNP were genotyping using Taqman 5’ nuclease allelic discrimination. For cytokine measurements we used the commercially available Enzyme-Linked Immunosorbent Assay (ELISA) kit. Our results show that the circulating IL-1β, IL-6, TNF-α, and IFN-γ were significantly (p < 0.001) elevated in EOS patients compared to suspected and sepsis-free control groups; and IL-1β –31C, IL-6 –174G, TNF-α –308G, and IFN-γ +874A alleles were associated with EOS in Saudi infants. In conclusion, analysis of cytokines concentrations and SNP for the four tested genes can be used as a predictor of sepsis outcome in newborns.

Clinical associations of host genetic variations in the genes of cytokines in critically ill patients

Host genetic variations may influence a changing profile of biochemical markers and outcome in patients with trauma/injury. The objective of this study was to assess clinical associations of single nucleotide polymorphisms (SNPs) in the genes of cytokines in critically ill patients. A total of 430 patients were genotyped for SNPs in the genes of pro- (IL1B, IL6, IL8) and anti-inflammatory (IL4, IL10, IL13) cytokines. The main end-points were sepsis, mortality and adult respiratory distress syndrome (ARDS). We evaluated the dynamic levels of bilirubin, blood urea nitrogen, creatine kinase, creatinine and lactate dehydrogenase in five points of measurements (between 1 and 14 days after admission) and correlated them with SNPs. High-producing alleles of proinflammatory cytokines protected patients against sepsis (IL1B -511A and IL8 -251A) and mortality (IL1B -511A). High-producing alleles of anti-inflammatory cytokines IL4 -589T and IL13 431A (144Gln) were less frequent in ARDS patients. The carriers of IL6 -174C/C genotypes were prone to the increased levels of biochemical markers and acute kidney and liver insufficiency. Genotype-dependent differences in the levels of biochemical indicators gradually increased to a maximal value on the 14th day after admission. These findings suggest that genetic variability in pro- and anti-inflammatory cytokines may contribute to different clinical phenotypes in patients at high risk of critical illness.

Association between IL-6-174G/C polymorphism and the risk of sepsis and mortality: a systematic review and meta-analysis

Background

Recent studies have reported the association between IL-6-174G/C polymorphism and sepsis. However, the results are inconclusive and conflicting. To better understand the role of IL-6-174G/C polymorphism in sepsis, we conducted a comprehensive meta-analysis.

Methodology

Literature search was conducted through PubMed, Embase, Web of Knowledge databases until July 29, 2013. The pooled odds ratios (ORs) and 95% confidence intervals (CIs) were calculated using fixed- or random-effect model based on heterogeneity test in total and subgroup analyses.

Results

Twenty studies on the risk of sepsis and seven studies on sepsis mortality were included. None of the results showed evidence of a significant association between IL-6-174G/C polymorphism and sepsis risk in overall analysis or subgroup analyses based on sepsis type, ethnicity, source of control and age under any genetic model (the allele comparison, the codominant, the recessive or the dominant model). Although there was a statistically significant association between IL-6-174 G/C polymorphism and sepsis-related mortality under the recessive model, the significance did not exist after Bonferroni’s correction.

Conclusions

Current evidence does not support a direct effect of IL-6-174 G/C polymorphism on the risk of sepsis. In addition, there was no association between IL-6-174 G/C polymorphism and sepsis mortality after Bonferroni’s correction. Further analyses of gene-environment interactions and more studies based on larger sample size and homogeneous sepsis patients are required.

Mortality related to invasive infections, sepsis, and septic shock in critically ill children in Australia and New Zealand, 2002-13: a multicentre retrospective cohort study

BACKGROUND

Severe infections kill more than 4·5 million children every year. Population-based data for severe infections in children requiring admission to intensive care units (ICUs) are scarce. We assessed changes in incidence and mortality of severe infections in critically ill children in Australia and New Zealand.

METHODS

We did a retrospective multicentre cohort study of children requiring intensive care in Australia and New Zealand between 2002 and 2013, with data from the Australian and New Zealand Paediatric Intensive Care Registry. We included children younger than 16 years with invasive infection, sepsis, or septic shock. We assessed incidence and mortality in the ICU for 2002-07 versus 2008-13.

FINDINGS

During the study period, 97 127 children were admitted to ICUs, 11 574 (11·9%) had severe infections, including 6688 (6·9%) with invasive infections, 2847 (2·9%) with sepsis, and 2039 (2·1%) with septic shock. Age-standardised incidence increased each year by an average of 0·56 cases per 100 000 children (95% CI 0·41-0·71) for invasive infections, 0·09 cases per 100 000 children (0·00-0·17) for sepsis, and 0·08 cases per 100 000 children (0·04-0·12) for septic shock. 260 (3·9%) of 6688 patients with invasive infection died, 159 (5·6%) of 2847 with sepsis died, and 346 (17·0%) of 2039 with septic shock died, compared with 2893 (3·0%) of all paediatric ICU admissions. Children admitted with invasive infections, sepsis, and septic shock accounted for 765 (26·4%) of 2893 paediatric deaths in ICUs. Comparing 2008-13 with 2002-07, risk-adjusted mortality decreased significantly for invasive infections (odds ratio 0·72, 95% CI 0·56-0·94; p=0·016), and for sepsis (0·66, 0·47-0·93; p=0·016), but not significantly for septic shock (0·79, 0·61-1·01; p=0·065).

INTERPRETATION

Severe infections remain a major cause of mortality in paediatric ICUs, representing a major public health problem. Future studies should focus on patients with the highest risk of poor outcome, and assess the effectiveness of present sepsis interventions in children.

FUNDING

National Medical Health and Research Council, Australian Resuscitation Outcomes Consortium, Centre of Research Excellence (1029983).

Sepsis biomarkers

Sepsis is the most frequent cause of death in non-coronary intensive care units (ICUs). In the past 10 years, progress has been made in the early identification of septic patients and in their treatment and these improvements in support and therapy mean that the mortality is gradually decreasing but it still remains unacceptably high. Leaving clinical diagnosis aside, the laboratory diagnostics represent a complex range of investigations that can place significant demands on the system given the speed of response required. There are hundreds of biomarkers which could be potentially used for diagnosis and prognosis in septic patients. The main attributes of successful markers would be high sensitivity, specificity, possibility of bed-side monitoring, and financial accessibility. Only a fraction is used in routine clinical practice because many lack sufficient sensitivity or specificity. The following review gives a short overview of the current epidemiology of sepsis, its pathogenesis and state-of-the-art knowledge on the use of specific biochemical, hematological and immunological parameters in its diagnostics. Prospective approaches towards discovery of new diagnostic biomarkers have been shortly mentioned.

Invasive meningococcal disease: a disease of the endothelial cells

Neisseria meningitidis is an extracellular pathogen, which, once in the bloodstream, has the ability to form microcolonies on the apical surface of endothelia. Pathogen interaction with microvessels is mediated by bacterial type IV pili and two receptors on endothelial cells: CD147 and the β2-adrenoceptor. CD147 facilitates the adhesion of diplococci to the endothelium, whereas the β2-adrenoceptor facilitates cell signaling, and crossing of the blood-brain barrier. In this review, we discuss how meningococcal interaction with endothelial cells is responsible for the specific clinical features of invasive meningococcal infection such as meningitis, and a peripheral thrombotic/vascular leakage syndrome possibly leading to purpura fulminans.

Genetic polymorphisms and sepsis in premature neonates

Identifying single nucleotide polymorphisms (SNPs) in the genes involved in sepsis may help to clarify the pathophysiology of neonatal sepsis. The aim of this study was to evaluate the relationships between sepsis in pre-term neonates and genes potentially involved in the response to invasion by infectious agents. The study involved 101 pre-term neonates born between June 2008 and May 2012 with a diagnosis of microbiologically confirmed sepsis, 98 pre-term neonates with clinical sepsis and 100 randomly selected, otherwise healthy pre-term neonates born during the study period. During the study, 47 SNPs in 18 candidate genes were genotyped on Guthrie cards using an ABI PRISM 7900 HT Fast real-time and MAssARRAY for nucleic acids instruments. Genotypes CT and TT of rs1143643 (the IL1β gene) and genotype GG of rs2664349GG (the MMP-16 gene) were associated with a significantly increased overall risk of developing sepsis (p = 0.03, p = 0.05 and p = 0.03), whereas genotypes AG of rs4358188 (the BPI gene) and CT of rs1799946 (the DEFβ1 gene) were associated with a significantly reduced risk of developing sepsis (p = 0.05 for both). Among the patients with bacteriologically confirmed sepsis, only genotype GG of rs2664349 (the MMP-16 gene) showed a significant association with an increased risk (p = 0.02). Genotypes GG of rs2569190 (the CD14 gene) and AT of rs4073 (the IL8 gene) were associated with a significantly increased risk of developing severe sepsis (p = 0.05 and p = 0.01). Genotype AG of rs1800629 (the LTA gene) and genotypes CC and CT of rs1341023 (the BPI gene) were associated with a significantly increased risk of developing Gram-negative sepsis (p = 0.04, p = 0.04 and p = 0.03). These results show that genetic variability seems to play a role in sepsis in pre-term neonates by influencing susceptibility to and the severity of the disease, as well as the risk of having disease due to specific pathogens.

Association between heat shock protein 70 gene polymorphisms and clinical outcomes in intensive care unit patients with sepsis

Objective:

The objective of the following study is to evaluate the associations between single nucleotide polymorphisms (SNPs) in the Heat Shock Protein 70 (HSP70) gene, gene expression of interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-α) and medical intensive care unit (MICU) stay and organ failure in sepsis.

Materials and Methods:

MICU patients with sepsis were genotyped for rs1061581, rs2227956, rs1008438 and rs1043618 polymorphisms in HSP70 gene using polymerase chain reaction (PCR)-restriction fragment length polymorphism analysis or allele-specific PCR. Messenger ribonucleic acid (mRNA) expression of IL-6 and TNF-α were quantitated in peripheral blood lymphocytes. Outcomes were recorded.

Results:

108 patients (48 male) aged 40.7 ± 16.0 (mean ± standard deviation) years included H1N1 infection (36), scrub typhus (29) and urosepsis (12). Seventy-one (65.7%) had dysfunction of three or more organ systems, 66 patients (61.1%) were treated by mechanical ventilation, 21 (19.4%) needed dialysis. ICU stay was 9.3 ± 7.3 days. Mortality was 38.9%. One or more SNPs were noted in 101/108 (93.5%) and organ failure was noted in only 1/7 patients without a single SNP. The A allelotypes of rs1061581 and rs1008438 were associated with hematological dysfunction (P = 0.03 and 0.07) and longer ICU stay (P = 0.05 and 0.04), whereas IL-6 and TNF-α mRNA levels were associated with central nervous system dysfunction.

Conclusions:

HSP70 genotypes may determine some adverse outcomes in patients with sepsis.

A multibiomarker-based outcome risk stratification model for adult septic shock*

OBJECTIVES

Clinical trials in septic shock continue to fail due, in part, to inequitable and sometimes unknown distribution of baseline mortality risk between study arms. Investigators advocate that interventional trials in septic shock require effective outcome risk stratification. We derived and tested a multibiomarker-based approach to estimate mortality risk in adults with septic shock.

DESIGN

Previous genome-wide expression studies identified 12 plasma proteins as candidates for biomarker-based risk stratification. The current analysis used banked plasma samples and clinical data from existing studies. Biomarkers were assayed in plasma samples obtained from 341 subjects with septic shock within 24 hours of admission to the ICU. Classification and regression tree analysis was used to generate a decision tree predicting 28-day mortality based on a combination of both biomarkers and clinical variables. The derived tree was first tested in an independent cohort of 331 subjects, then calibrated using all subjects (n = 672), and subsequently validated in another independent cohort (n = 209).

SETTING

Multiple ICUs in Canada, Finland, and the United States.

SUBJECTS

Eight hundred eighty-one adults with septic shock or severe sepsis.

INTERVENTION

None.

MEASUREMENTS AND MAIN RESULTS

The derived decision tree included five candidate biomarkers, admission lactate concentration, age, and chronic disease burden. In the derivation cohort, sensitivity for mortality was 94% (95% CI, 87-97), specificity was 56% (50-63), positive predictive value was 50% (43-57), and negative predictive value was 95% (89-98). Performance was comparable in the test cohort. The calibrated decision tree had the following test characteristics in the validation cohort: sensitivity 85% (76-92), specificity 60% (51-69), positive predictive value 61% (52-70), and negative predictive value 85% (75-91).

CONCLUSIONS

We have derived, tested, calibrated, and validated a risk stratification tool and found that it reliably estimates the probability of mortality in adults with septic shock.