Extracellular CIRP decreases Siglec-G expression on B-1a cells skewing them towards a pro-inflammatory phenotype in sepsis

BACKGROUND

Sepsis is a life-threatening disease syndrome caused by a dysregulated host response to infection and injury. Extracellular cold-inducible RNA-binding protein (eCIRP) acts as a damage-associated molecular pattern. Peritoneal cavity (PerC) B-1a cells attenuate inflammation and tissue injury by spontaneous releasing natural IgM and IL-10. Sialic acid-binding immunoglobulin-type lectin-G (Siglec-G) is a CD33-related receptor highly expressed in B-1a cells to serve critical immunoregulatory functions. In sepsis, B-1a cell numbers in PerC are decreased. We hypothesized that eCIRP causes the reduction of PerC B-1a cells and alters their function during sepsis.

METHODS

Sepsis was induced in WT and CIRP-/- mice by cecal ligation and puncture (CLP). PerC washout cells were collected and B-1a cells and Siglec-G were assessed by flow cytometry. Mice were i.p. injected with recombinant murine (rm) CIRP and after 20 h, Siglec-G expression in PerC B-1a cells were assessed. PerC B-1a cells were treated with rmCIRP for 4 h and Siglec-G expression was assessed. PerC B-1a cells were pre-treated with anti-Siglec-G Ab and then after stimulated with rmCIRP for 24 h, IL-6 levels in the culture supernatants were assessed.

RESULTS

eCIRP levels in the PerC were elevated in septic mice. In WT mice, the frequencies and numbers of total and Siglec-G+ B-1a cells in the PerC were significantly decreased in the CLP group compared to sham group, whereas in CIRP-/- mice, their frequencies and numbers in sepsis were significantly rescued compared to WT septic mice. Mice injected with rmCIRP showed decreased frequencies and numbers of total and Siglec-G+ PerC B-1a cells compared to PBS-injected mice. In vitro treatment of PerC B-1a cells with rmCIRP demonstrated significant reduction in Siglec-G mRNA and protein compared to PBS group. PerC B-1a cells treated with anti-Siglec-G Ab had significantly higher production of IL-6 in response to rmCIRP compared to IgG control. Anti-Siglec-G Ab treated B-1a cells co-cultured with macrophages produced significantly higher levels of IL-6, and TNF-α, and lower levels of IL-10 compared to IgG-treated B-1a cells and macrophage co-cultures stimulated with rmCIRP.

CONCLUSION

eCIRP reduces PerC B-1a cell pool and skews them to a pro-inflammatory phenotype by downregulating Siglec-G expression. Targeting eCIRP will retain Siglec-G expressing B-1a cells in the PerC and preserve their anti-inflammatory function in sepsis.

Significance of Heme and Heme Degradation in the Pathogenesis of Acute Lung and Inflammatory Disorders

The heme molecule serves as an essential prosthetic group for oxygen transport and storage proteins, as well for cellular metabolic enzyme activities, including those involved in mitochondrial respiration, xenobiotic metabolism, and antioxidant responses. Dysfunction in both heme synthesis and degradation pathways can promote human disease. Heme is a pro-oxidant via iron catalysis that can induce cytotoxicity and injury to the vascular endothelium. Additionally, heme can modulate inflammatory and immune system functions. Thus, the synthesis, utilization and turnover of heme are by necessity tightly regulated. The microsomal heme oxygenase (HO) system degrades heme to carbon monoxide (CO), iron, and biliverdin-IXα, that latter which is converted to bilirubin-IXα by biliverdin reductase. Heme degradation by heme oxygenase-1 (HO-1) is linked to cytoprotection via heme removal, as well as by activity-dependent end-product generation (i.e., bile pigments and CO), and other potential mechanisms. Therapeutic strategies targeting the heme/HO-1 pathway, including therapeutic modulation of heme levels, elevation (or inhibition) of HO-1 protein and activity, and application of CO donor compounds or gas show potential in inflammatory conditions including sepsis and pulmonary diseases.

Rapid Next-Generation Sequencing-Based Diagnostics of Bacteremia in Septic Patients

The increasing incidence of bloodstream infections including sepsis is a major challenge in intensive care units worldwide. However, current diagnostics for pathogen identification mainly depend on culture- and molecular-based approaches, which are not satisfactory regarding specificity, sensitivity, and time to diagnosis. Herein, we established a complete diagnostic workflow for real-time high-throughput sequencing of cell-free DNA from plasma based on nanopore sequencing for the detection of the causative agents, which was applied to the analyses of eight samples from four septic patients and three healthy controls, and subsequently validated against standard next-generation sequencing results. By optimization of library preparation protocols for short fragments with low input amounts, a 3.5-fold increase in sequencing throughput could be achieved. With tailored bioinformatics workflows, all eight septic patient samples were found to be positive for relevant pathogens. When considering time to diagnosis, pathogens were identified within minutes after start of sequencing. Moreover, an extrapolation of real-time sequencing performance on a cohort of 239 septic patient samples revealed that more than 90% of pathogen hits would have also been detected using the optimized MinION workflow. Reliable identification of pathogens based on circulating cell-free DNA sequencing using optimized workflows and real-time nanopore-based sequencing can be accomplished within 5 to 6 hours following blood draw. Therefore, this approach might provide therapy-relevant results in a clinically critical timeframe.

Reduning injection and its effective constituent luteoloside protect against sepsis partly via inhibition of HMGB1/TLR4/NF-κB/MAPKs signaling pathways

ETHNOPHARMACOLOGICAL RELEVANCE

Reduning injection (RDN), a popular traditional Chinese medicine, formulated by three herbs (i.e., Artemisia carvifolia Buch.-Ham. ex Roxb., Lonicera japonica Thunb., and Gardenia jasminoides J. Ellis), has been widely used to treat upper respiratory infectious diseases in China.

AIM OF THE STUDY

To investigate the protective effect of RDN on both lipopolysaccharides (LPS)- and cecal ligation and puncture (CLP)-induced septic mice. To identify the potentially effective constituent, and to determine its protective effect and underlying mechanism in vivo and in vitro.

MATERIALS AND METHODS

Male C57BL/6 mice were used to establish septic model by tail intravenous injection of 4 mg/kg LPS or CLP surgery. After modeling, mice were administered by tail intravenous injection of RDN in the dose of 16 or 8 mL/kg/day. The mortality, histopathology, plasma levels of inflammatory cytokines were evaluated respectively. In addition, we screened the potentially effective substances of RDN against sepsis by detecting the nitric oxide (NO) production in LPS-stimulated Raw 264.7 cells and verified the effect of luteoloside in CLP-induced septic mice subsequently. Finally, the underlying mechanisms of RDN and luteoloside were investigated in the inflammatory model in vitro.

RESULTS

Administration of RDN significantly reduced the mortality and increased the survival rate in both LPS- and CLP-induced septic mice. Meanwhile, RDN reduced the release of inflammatory cytokines accompanied by alleviating the organs damage of lung, liver, and kidney in CLP-induced septic mice. Moreover, several components from Gardenia jasminoides J. Ellis extract (ZZ) or Lonicera japonica Thunb and Artemisia carvifolia Buch.-Ham. ex Roxb extract (JQ) as well as the constituents of luteoloside, quercetin, and caffeic acid were screened out to have obvious anti-inflammatory activity, which may be the potentially effective substances of RDN against sepsis. We further verified the protective role of luteoloside in CLP-induced septic mice. In addition, RDN and luteoloside significantly inhibited both the secretion and translocation of mobility group box (HMGB)1, and HMGB1-mediated activation of TLR4/NF-κB/MAPKs signaling pathways.

CONCLUSION

RDN and its effective constituent luteoloside exhibited a significant protective effect against sepsis, which were potential candidate drugs for treatment of sepsis. The mechanism of antisepsis partly was related to inhibition of HMGB1/TLR4/NF-κB/MAPKs signaling pathways. The results provide an evidence base for the follow-up clinical application of RDN in treatment of sepsis.

Mortality, neurodevelopmental impairments, and economic outcomes after invasive group B streptococcal disease in early infancy in Denmark and the Netherlands: a national matched cohort study

Background

Group B Streptococcus (GBS) disease is a leading cause of neonatal death, but its long-term effects have not been studied after early childhood. The aim of this study was to assess long-term mortality, neurodevelopmental impairments (NDIs), and economic outcomes after infant invasive GBS (iGBS) disease up to adolescence in Denmark and the Netherlands.

Methods

For this cohort study, children with iGBS disease were identified in Denmark and the Netherlands using national medical and administrative databases and culture results that confirmed their diagnoses. Exposed children were defined as having a history of iGBS disease (sepsis, meningitis, or pneumonia) by the age of 89 days. For each exposed child, ten unexposed children were randomly selected and matched by sex, year and month of birth, and gestational age. Mortality data were analysed with the use of Cox proportional hazards models. NDI data up to adolescence were captured from discharge diagnoses in the National Patient Registry (Denmark) and special educational support records (the Netherlands). Health care use and household income were also compared between the exposed and unexposed cohorts.

Findings

2258 children—1561 in Denmark (born from Jan 1, 1997 to Dec 31, 2017) and 697 in the Netherlands (born from Jan 1, 2000 to Dec 31, 2017)—were identified to have iGBS disease and followed up for a median of 14 years (IQR 7–18) in Denmark and 9 years (6–11) in the Netherlands. 366 children had meningitis, 1763 had sepsis, and 129 had pneumonia (in Denmark only). These children were matched with 22 462 children with no history of iGBS disease. iGBS meningitis was associated with an increased mortality at age 5 years (adjusted hazard ratio 4·08 [95% CI 1·78–9·35] for Denmark and 6·73 [3·76–12·06] for the Netherlands). Any iGBS disease was associated with an increased risk of NDI at 10 years of age, both in Denmark (risk ratio 1·77 [95% CI 1·44–2·18]) and the Netherlands (2·28 [1·64–3·17]). A history of iGBS disease was associated with more frequent outpatient clinic visits (incidence rate ratio 1·93 [95% CI 1·79–2·09], p<0·0001) and hospital admissions (1·33 [1·27–1·38], p<0·0001) in children 5 years or younger. No differences in household income were observed between the exposed and unexposed cohorts.

Interpretation

iGBS disease, especially meningitis, was associated with increased mortality and a higher risk of NDIs in later childhood. This previously unquantified burden underlines the case for a maternal GBS vaccine, and the need to track and provide care for affected survivors of iGBS disease.

Funding

The Bill & Melinda Gates Foundation.

Translations

For the Dutch and Danish translations of the abstract see Supplementary Materials section.

Extracorporeal Membrane Oxygenation for COVID-19 Respiratory Distress Syndrome: An Italian Society for Cardiac Surgery Report

An increased need of extracorporeal membrane oxygenation (ECMO) support is going to become evident as treatment of SARS-CoV-2 respiratory distress syndrome. This is the first report of the Italian Society for Cardiac Surgery (SICCH) on preliminary experience with COVID-19 patients receiving ECMO support. Data from 12 Italian hospitals participating in SICCH were retrospectively analyzed. Between March 1 and September 15, 2020, a veno-venous (VV) ECMO system was installed in 67 patients (94%) and a veno-arterio-venous ECMO in four (6%). Five patients required VA ECMO after initial weaning from VV ECMO. Thirty (42.2%) patients were weaned from ECMO, while 39 (54.9%) died on ECMO, and six (8.5%) died after ECMO removal. Overall hospital survival was 36.6% (n = 26). Main causes of death were multiple organ failure (n = 14, 31.1%) and sepsis (n = 11, 24.4%). On multivariable analysis, predictors of death while on ECMO support were older age (p = 0.048), elevated pre-ECMO C-reactive protein level (p = 0.048), higher positive end-expiratory pressure on ventilator (p = 0.036) and lower lung compliance (p = 0.032). If the conservative treatment is not effective, ECMO support might be considered as life-saving rescue therapy for COVID-19 refractory respiratory failure. However warm caution and thoughtful approaches for timely detection and treatment should be taken for such a delicate patients population.

How often is autopsy contributory in cases of sepsis?

This study sought to determine how often a medico-legal (coronial) autopsy contributes by identifying the source of infection when there has been a clinical diagnosis of sepsis prior to death. Autopsy reports were retrieved in which it was documented there had been a clinical diagnosis of sepsis preceding death. The autopsy report was reviewed to determine if a source for sepsis had been identified. It was found the autopsy was contributory in this respect in less than one fifth of all cases (35 of 198, 18%). It was also determined if there was a post-autopsy diagnosis of sepsis or if sepsis was excluded by a definite alternative diagnosis. During the study, of the 198 cases, sepsis was excluded by an alternative diagnosis in 78 (39%). Thus, the autopsy may be of more application to confirming or excluding a diagnosis of sepsis than identifying a source for sepsis.

Development and Validation of a Machine Learning Model to Estimate Bacterial Sepsis Among Immunocompromised Recipients of Stem Cell Transplant

IMPORTANCE

Sepsis disproportionately affects recipients of allogeneic hematopoietic cell transplant (allo-HCT), and timely detection is crucial. However, the atypical presentation of sepsis within this population makes detection challenging, and existing clinical sepsis tools have limited prognostic value among this high-risk population.

OBJECTIVE

To develop a full risk factor (demographic, transplant, clinical, and laboratory factors) and clinical factor-specific automated bacterial sepsis decision support tool for recipients of allo-HCT with potential bloodstream infections (PBIs).

DESIGN, SETTING, AND PARTICIPANTS

This prognostic study used data from adult recipients of allo-HCT transplanted at the Fred Hutchinson Cancer Research Center, Seattle, Washington, between June 2010 and June 2019 randomly divided into 70% modeling and 30% validation data sets. Tools were developed using the area under the curve (AUC) optimized SuperLearner, and their performance was compared with existing clinical sepsis tools: National Early Warning Score (NEWS), quick Sequential Organ Failure Assessment (qSOFA), and Systemic Inflammatory Response Syndrome (SIRS), using the validation data set. Data were analyzed between January and October of 2020.

MAIN OUTCOMES AND MEASURES

The primary outcome was high-sepsis risk bacteremia (culture confirmed gram-negative species, Staphylococcus aureus, or Streptococcus spp bacteremia), and the secondary outcomes were 10- and 28-day mortality. Tool discrimination and calibration were examined using accuracy metrics and expected vs observed probabilities.

RESULTS

Between June 2010 and June 2019, 1943 recipients of allo-HCT received their first transplant, and 1594 recipients (median [interquartile range] age at transplant, 54 [43-63] years; 911 [57.2%] men; 1242 individuals [77.9%] identifying as White) experienced at least 1 PBI. Of 8131 observed PBIs, 238 (2.9%) were high-sepsis risk bacteremia. Compared with high-sepsis risk bacteremia, the full decision support tool had the highest AUC (0.85; 95% CI, 0.81-0.89), followed by the clinical factor-specific tool (0.72; 95% CI, 0.66-0.78). SIRS had the highest AUC of existing tools (0.64; 95% CI, 0.57-0.71). The full decision support tool had the highest AUCs for PBIs identified in inpatient (0.82; 95% CI, 0.76-0.89) and outpatient (0.82; 95% CI, 0.75-0.89) settings and for 10-day (0.85; 95% CI, 0.79-0.91) and 28-day (0.80; 95% CI, 0.75-0.84) mortality.

CONCLUSIONS AND RELEVANCE

These findings suggest that compared with existing tools and the clinical factor-specific tool, the full decision support tool had superior prognostic accuracy for the primary (high-sepsis risk bacteremia) and secondary (short-term mortality) outcomes in inpatient and outpatient settings. If used at the time of culture collection, the full decision support tool may inform more timely sepsis detection among recipients of allo-HCT.

Protective Effect of Sirtuin 3 on CLP-Induced Endothelial Dysfunction of Early Sepsis by Inhibiting NF-κB and NLRP3 Signaling Pathways

It has been revealed that widespread vascular endothelial dysfunction occurs in septic shock, ultimately resulting in multiple organ failure. The mitochondrial deacetylase sirtuin 3 (SIRT3) is essential in the regulation of metabolism, anti-inflammation, and anti-oxidation. The purpose of this study is to investigate whether SIRT3 is associated with the pathological progression of endothelial dysfunction in sepsis. Septic shock model was induced by cecal ligation and puncture (CLP) surgery on wild-type C57BL/6 mice. We activated and inhibited the function of SIRT3 with honokiol (HKL) and 3-TYP, respectively, and then biochemical, inflammatory, and endothelial function parameters of vascular tissue and survival were determined after CLP. CLP significantly activated NF-κB and NLRP3 pathways and decreased survival rate, endothelium-dependent relaxation function, and expression of Ser1177 phosphorylation of endothelial nitric oxide synthase (p-eNOS). The activation of SIRT3 significantly attenuated the increases of NF-κB and NLRP3 pathways and the declines of p-eNOS, endothelium-dependent relaxation function, and survival rate in septic mice. However, it presented exactly opposite results if SIRT3 was suppressed. We suggested that SIRT3 had a critical protective effect against vascular inflammation and endothelial dysfunction in early sepsis. Our data support a potential therapeutic target in vascular dysfunction and septic shock.

Embryonic-Derived Myb- Macrophages Enhance Bacterial Clearance and Improve Survival in Rat Sepsis

Peritoneal resident macrophages play a key role in combating sepsis in the peritoneal cavity. We sought to determine if peritoneal transplantation of embryonic Myb^- "peritoneal-like" macrophages attenuate abdominal fecal sepsis. Directed differentiation of rodent pluripotent stem cells (PSCs) was used in factor-defined media to produce embryonic-derived large "peritoneal-like" macrophages (Ed-LPM) that expressed peritoneal macrophage markers and demonstrated phagocytic capacity. Preclinical in vivo studies determined Ed-LPM efficacy in rodent abdominal fecal sepsis with or without Meropenem. Ex vivo studies explored the mechanism and effects of Ed-LPM on host immune cell number and function, including phagocytosis, reactive oxygen species (ROS) production, efferocytosis and apoptosis. Ed-LPM reduced sepsis severity by decreasing bacterial load in the liver, spleen and lungs. Ed-LPM therapy significantly improved animal survival by ~30% and reduced systemic bacterial burden to levels comparable to Meropenem therapy. Ed-LPM therapy decreased peritoneal TNFα while increasing IL-10 concentrations. Ed-LPMs enhanced peritoneal macrophage phagocytosis of bacteria, increased macrophage production of ROS and restored homeostasis via apoptosis and efferocytosis-induced clearance of neutrophils. In conclusion, Ed-LPM reduced systemic sepsis severity, improved survival and reduced bacterial load by enhancing peritoneal macrophage bacterial phagocytosis and killing and clearance of intra-peritoneal neutrophils. Macrophage therapy may be a potential strategy to address sepsis.

Cutaneous calciphylaxis of the glans penis presenting as a gangrenous ulceration

Report _Case Presentation X Photo Vignette _Letter Authors declare that the contents of this article are their own original unpublished findings. Title: Cutaneous calciphylaxis of the glans penis presenting as a gangrenous ulceration Authors: Marie Danset, Cécile Lesort, Denis Jullien, Jean Kanitakis Affiliations: Dermatology Department, Edouard Herriot Hospital, Hospices Civils de Lyon, Claude Bernard Lyon I University, Lyon, France Corresponding Author: Jean Kanitakis, Department of Dermatology, Edouard Herriot Hospital Group, 69437 Lyon Cedex 03, France, Tel: 33-472110301, Email: jean.kanitakis@univ-lyon1.fr Abstract: Calciphylaxis is a rare microvascular disorder causing necrotic skin ulcers. It is characterized by deposits of calcium within vascular walls but its precise pathogenesis remains poorly understood. A major risk factor is end-stage renal disease on dialysis. We report a 67-year-old man with calciphylaxis revealed by an unusual necrotic ulcer of the glans penis. The patient also presented with bilateral panniculitis of the thighs and a calf ulcer. All those lesions were painful, highlighting the value of pain as a diagnostic clue. Penile involvement of calciphylaxis is rare and biopsy is often avoided in this area. However, rapid diagnosis of calciphylaxis is important because early treatment has a better chance of being successful. Our patient's condition deteriorated rapidly with development of bilateral retinal artery occlusion and he died shortly thereafter. This case further highlights the fact that calciphylaxis is a systemic vascular disease with an ominous prognosis.

Do COVID-19 Infections Result in a Different Form of Secondary Hemophagocytic Lymphohistiocytosis

The coronavirus disease 2019 (COVID-19) pandemic, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has resulted in significant morbidity and mortality across the world, with no current effective treatments available. Recent studies suggest the possibility of a cytokine storm associated with severe COVID-19, similar to the biochemical profile seen in hemophagocytic lymphohistiocytosis (HLH), raising the question of possible benefits that could be derived from targeted immunosuppression in severe COVID-19 patients. We reviewed the literature regarding the diagnosis and features of HLH, particularly secondary HLH, and aimed to identify gaps in the literature to truly clarify the existence of a COVID-19 associated HLH. Diagnostic criteria such as HScore or HLH-2004 may have suboptimal performance in identifying COVID-19 HLH-like presentations, and criteria such as soluble CD163, NK cell activity, or other novel biomarkers may be more useful in identifying this entity.

Bacterial contamination of blood products in Africa

BACKGROUND

Bacterial contamination of blood components (notably platelets) remains a leading infectious risk to the blood supply. There has been extensive research in high-income countries to characterize the risk of bacterial contamination along with adoption of strategies to mitigate that risk. By contrast, related data in Africa are lacking.

STUDY DESIGN AND METHODS

An electronic survey was distributed to members of African Society of Blood Transfusion to assess existing or planned measures at African blood centers and hospitals to mitigate bacterial contamination of blood products. A literature review of studies pertaining to related transfusion-associated risk in Africa was conducted to complement the findings.

RESULTS

Forty-five responses were received, representing 16 African countries. All respondents were urban, either in blood centers (n = 36) or hospital-based transfusion services (n = 9). Reported measures included skin disinfection (n = 41 [91.1%]); diversion pouches (n = 14 [31.1%]); bacterial culture (n = 9 [20%]); pathogen reduction (PR) (n = 3 [6.7%]); and point-of-release testing (PoRT) (n = 2 [4.4%]). Measures being considered for implementation included: skin disinfection (n = 2 [4.4%]); diversion pouches (n = 2 [4.4%]); bacterial culture n = 14 (31.1%); PR (n = 11 [24.4%]); and PoRT (n = 4 [8.9%]). Of the 38 respondents who reported collection of platelets, 14 (36.8%) and 8 (21.1%) reported using diversion pouches and bacterial culture, respectively. The literature review identified 36 studies on the epidemiology of bacterial contamination and septic transfusion reactions in Africa; rates of contamination ranged from 0% to 17.9%.

CONCLUSIONS

The findings suggest that prevention of bacterial contamination of blood components and transfusion-associated sepsis in Africa remains neglected. Regional preventive measures have not been widely adopted.

Humanized Mice as a Tool to Study Sepsis-More Than Meets the Eye

(1) Background. Repetitive animal studies that have disappointed upon translation into clinical therapies have led to an increased appreciation of humanized mice as a remedy to the shortcomings of rodent-based models. However, their limitations have to be understood in depth. (2) Methods. This is a narrative, comprehensive review of humanized mice and sepsis literature to understand the model's benefits and shortcomings. (3) Results: Studies involving humanized models of sepsis include bacterial, viral, and protozoan etiology. Humanized mice provided several unique insights into the etiology and natural history of sepsis and are particularly useful in studying Ebola, and certain viral and protozoan infections. However, studies are relatively sparse and based on several different models of sepsis and humanized animals. (4) Conclusions. The utilization of humanized mice as a model for sepsis presents complex limitations that, once surpassed, hold some potential for the advancement of sepsis etiology and treatment.

Machine Learning Identifies Complicated Sepsis Course and Subsequent Mortality Based on 20 Genes in Peripheral Blood Immune Cells at 24 H Post-ICU Admission

A complicated clinical course for critically ill patients admitted to the intensive care unit (ICU) usually includes multiorgan dysfunction and subsequent death. Owing to the heterogeneity, complexity, and unpredictability of the disease progression, ICU patient care is challenging. Identifying the predictors of complicated courses and subsequent mortality at the early stages of the disease and recognizing the trajectory of the disease from the vast array of longitudinal quantitative clinical data is difficult. Therefore, we attempted to perform a meta-analysis of previously published gene expression datasets to identify novel early biomarkers and train the artificial intelligence systems to recognize the disease trajectories and subsequent clinical outcomes. Using the gene expression profile of peripheral blood cells obtained within 24 h of pediatric ICU (PICU) admission and numerous clinical data from 228 septic patients from pediatric ICU, we identified 20 differentially expressed genes predictive of complicated course outcomes and developed a new machine learning model. After 5-fold cross-validation with 10 iterations, the overall mean area under the curve reached 0.82. Using a subset of the same set of genes, we further achieved an overall area under the curve of 0.72, 0.96, 0.83, and 0.82, respectively, on four independent external validation sets. This model was highly effective in identifying the clinical trajectories of the patients and mortality. Artificial intelligence systems identified eight out of twenty novel genetic markers (SDC4, CLEC5A, TCN1, MS4A3, HCAR3, OLAH, PLCB1, and NLRP1) that help predict sepsis severity or mortality. While these genes have been previously associated with sepsis mortality, in this work, we show that these genes are also implicated in complex disease courses, even among survivors. The discovery of eight novel genetic biomarkers related to the overactive innate immune system, including neutrophil function, and a new predictive machine learning method provides options to effectively recognize sepsis trajectories, modify real-time treatment options, improve prognosis, and patient survival.

Ion and Water Transport in Neutrophil Granulocytes and Its Impairment during Sepsis

Neutrophil granulocytes are the vanguard of innate immunity in response to numerous pathogens. Their activity drives the clearance of microbe- and damage-associated molecular patterns, thereby contributing substantially to the resolution of inflammation. However, excessive stimulation during sepsis leads to cellular unresponsiveness, immunological dysfunction, bacterial expansion, and subsequent multiple organ dysfunction. During the short lifespan of neutrophils, they can become significantly activated by complement factors, cytokines, and other inflammatory mediators. Following stimulation, the cells respond with a defined (electro-)physiological pattern, including depolarization, calcium influx, and alkalization as well as with increased metabolic activity and polarization of the actin cytoskeleton. Activity of ion transport proteins and aquaporins is critical for multiple cellular functions of innate immune cells, including chemotaxis, generation of reactive oxygen species, and phagocytosis of both pathogens and tissue debris. In this review, we first describe the ion transport proteins and aquaporins involved in the neutrophil ion-water fluxes in response to chemoattractants. We then relate ion and water flux to cellular functions with a focus on danger sensing, chemotaxis, phagocytosis, and oxidative burst and approach the role of altered ion transport protein expression and activity in impaired cellular functions and cell death during systemic inflammation as in sepsis.

Efficacy and safety of blood purification in the treatment of deep burns: A systematic review and meta-analysis

INTRODUCTION

This meta-analysis aimed to systematically review and evaluate randomized controlled trials (RCTs) and cohort studies examining the efficacy and safety of blood purification in the treatment of patients with deep burns.

METHODS

The PubMed, Cochrane Library, and Embase databases and relevant references were systematically searched for RCTs and cohort studies published until the end of September 2020 to investigate the potential of blood purification in improving the prognosis of severely burned patients. The primary outcome of this systematic review was overall patient mortality; secondary outcomes included the incidence of sepsis and infection prevention (vital signs and routine blood tests).

RESULTS

A total of 6 RCTs and 1 cohort study were included, with a total of 538 burn patients (274 patients who received blood purification and 264 control patients). Compared with patients who received conventional treatment, those treated with blood purification displayed significant 2-day reduction in mortality and sepsis with relative risks of 0.62 and 0.41, respectively (95% confidence intervals [CIs], 0.74-0.82 and 0.25-0.67, respectively; P < .05). In terms of vital signs and blood biochemistry, the respiratory rates and blood urea nitrogen levels of patients in the blood purification group 3 days post-treatment were significantly higher than those in the control group (randomized standard deviations (SMDs), 0.78 and 0.77, respectively; 95% CIs, 0.33-1.23 and 1.22-0.31, respectively; P < .05). However, there were no significant differences between groups on day 3 with regard to temperature (P = .32), heart rate (P = .26), white blood cell count (P = .54), or neutrophil count (P = .74), potentially owing to the small sample size or the relatively short intervention time. Heterogeneous differences existed between the groups with respect to blood urea nitrogen (SMD = -1.22; 95% CI, -2.16 to -0.40; P < .00001) and Cr (SMD = -3.13; 95% CI, -4.92 to -1.33; P < .00001) on day 7. No systematic adverse events occurred.

CONCLUSIONS

Blood purification treatment for deep burn patients can significantly reduce the mortality rate and the incidence of complications.

KLF4 down-regulation resulting from TLR4 promotion of ERK1/2 phosphorylation underpins inflammatory response in sepsis

Sepsis is a systemic inflammatory response to invading pathogens, leading to high mortality rates in intensive care units worldwide. Krüppel-like factor 4 (KLF4) is an important anti-inflammatory transcription factor. In this study, we investigate the anti-inflammatory role of KLF4 in caecal ligation and puncture (CLP)-induced septic mice and lipopolysaccharide (LPS)-induced RAW264.7 cells and its potential mechanism. We found that KLF4 was down-regulated in CLP-induced septic mice and in LPS-induced RAW264.7 cells, and that its overexpression led to increased survival rates of septic mice along with inhibited inflammatory response in vivo and in vitro. ITGA2B was up-regulated in the setting of sepsis and was inhibited by KLF4 overexpression. ITGA2B knock-down mimicked the effects of KLF4 overexpression on septic mice and LPS-induced RAW264.7 cells. TLR4 promoted the phosphorylation of ERK1/2 and then up-regulated the ubiquitination and the degradation of KLF4, thereby elevating the expression of ITGA2B. Moreover, TLR4 knock-down or treatment with PD98059 (a MEK inhibitor) inhibited inflammatory response in the setting of sepsis in vivo and in vitro. Furthermore, this effect of PD98059 treatment was lost upon KLF4 knock-down. Collectively, these results explain the down-regulation of KLF4 in sepsis, namely via TLR4 promotion of ERK1/2 phosphorylation, and identify ITGA2B as the downstream gene of KLF4, thus highlighting the anti-inflammatory role of KLF4 in sepsis.

Assessment of Incidence and Factors Associated With Severe Maternal Morbidity After Delivery Discharge Among Women in the US

IMPORTANCE

Previous efforts to examine severe maternal morbidity (SMM) in the US have focused on delivery hospitalizations. Little is known about de novo SMM that occurs after delivery discharge.

OBJECTIVE

To investigate the incidence, timing, factors, and maternal characteristics associated with de novo SMM after delivery discharge among women in the US.

DESIGN, SETTING, AND PARTICIPANTS

In this retrospective cohort study, data from the IBM MarketScan Multi-State Medicaid database and the IBM MarketScan Commercial Claims and Encounters database were used to construct a sample of women aged 15 to 44 years who delivered between January 1, 2010, and September 30, 2014. Severe maternal morbidity was reported by the timing of diagnosis, and the associated maternal characteristics were examined. Women in the Medicaid and commercial insurance sample were classified into 3 distinct outcome groups: (1) those without any SMM during the delivery hospitalization and the postdelivery period (reference group), (2) those who exhibited at least 1 factor associated with SMM during the delivery hospitalization, and (3) those who exhibited any factor associated with de novo SMM after delivery discharge (defined as SMM that was first diagnosed in the inpatient setting during the 6 weeks [or 42 days] after discharge from the delivery hospitalization, conditional on no factor associated with SMM being identified during delivery). Data were analyzed from February to July 2020.

EXPOSURES

Timing of SMM diagnosis.

MAIN OUTCOMES AND MEASURES

Women with SMM were identified using diagnosis and procedure codes from the International Classification of Diseases, Ninth Revision, Clinical Modification for the 21 factors associated with SMM that were developed by the Centers for Disease Control and Prevention.

RESULTS

A total of 2 667 325 women in the US with delivery hospitalizations between 2010 and 2014 were identified; of those, 809 377 women (30.3%) had Medicaid insurance (30.3%; mean [SD] age, 25.6 [5.5] years; 51.1% White), and 1 857 948 women (69.7%; mean [SD] age, 30.6 [5.4] years; 36.4% from the southern region of the US) had commercial insurance. Among those with Medicaid insurance, 17 584 women (2.2%) experienced SMM during the delivery hospitalization, and 3265 women (0.4%) experienced de novo SMM after delivery discharge. Among those with commercial insurance, 32 079 women (1.7%) experienced SMM during the delivery hospitalization, and 5275 women (0.3%) experienced de novo SMM after hospital discharge. A total of 5275 SMM cases (14.1%) and 3265 SMM cases (15.7%) among women with commercial and Medicaid insurance, respectively, developed de novo within 6 weeks after hospital discharge; of those, 3993 cases (75.7%) in the commercial insurance cohort and 2399 cases (73.5%) in the Medicaid cohort were identified in the first 2 weeks after discharge. The most common factors associated with SMM varied based on the timing of diagnosis. In the Medicaid population, non-Hispanic Black women (adjusted odds ratio [aOR], 1.53; 95% CI, 1.48-1.58), Hispanic women (aOR, 1.46; 95% CI, 1.37-1.57), and women of other races or ethnicities (aOR, 1.40; 95% CI, 1.33-1.47) had higher rates of SMM during delivery hospitalization than non-Hispanic White women; however, only the disparity between Black and White women (aOR, 1.69; 95% CI, 1.57-1.81) persisted into the postdischarge period.

CONCLUSIONS AND RELEVANCE

In this study, 15.7% of SMM cases in the Medicaid cohort and 14.1% of SMM cases in the commercial insurance cohort first occurred after the delivery hospitalization, with notable disparities in factors and maternal characteristics associated with the development of SMM. These findings suggest a need to expand the focus of SMM assessment to the postdelivery discharge period.

Granzyme A inhibition reduces inflammation and increases survival during abdominal sepsis

Aims: Peritonitis is one of the most common causes of sepsis, a serious syndrome characterized by a dysregulated systemic inflammatory response. Recent evidence suggests that Granzyme A (GzmA), a serine protease mainly expressed by NK and T cells, could act as a proinflammatory mediator and could play an important role in the pathogenesis of sepsis. This work aims to analyze the role and the therapeutic potential of GzmA in the pathogenesis of peritoneal sepsis. Methods: The level of extracellular GzmA as well as GzmA activity were analyzed in serum from healthy volunteers and patients with confirmed peritonitis and were correlated with the Sequential Organ Failure Assessment (SOFA) score. Peritonitis was induced in C57Bl/6 (WT) and GzmA-/- mice by cecal ligation and puncture (CLP). Mice were treated intraperitoneally with antibiotics alone or in combination serpinb6b, a specific GzmA inhibitor, for 5 days. Mouse survival was monitored during 14 days, levels of some proinflammatory cytokines were measured in serum and bacterial load and diversity was analyzed in blood and spleen at different times. Results: Clinically, elevated GzmA was observed in serum from patients with abdominal sepsis suggesting that GzmA plays an important role in this pathology. In the CLP model GzmA deficient mice, or WT mice treated with an extracellular GzmA inhibitor, showed increased survival, which correlated with a reduction in proinflammatory markers in both serum and peritoneal lavage fluid. GzmA deficiency did not influence bacterial load in blood and spleen and GzmA did not affect bacterial replication in macrophages in vitro, indicating that GzmA has no role in bacterial control. Analysis of GzmA in lymphoid cells following CLP showed that it was mainly expressed by NK cells. Mechanistically, we found that extracellular active GzmA acts as a proinflammatory mediator in macrophages by inducing the TLR4-dependent expression of IL-6 and TNFα. Conclusions: Our findings implicate GzmA as a key regulator of the inflammatory response during abdominal sepsis and provide solid evidences about its therapeutic potential for the treatment of this severe pathology.

Targeting Complement C5a Receptor 1 for the Treatment of Immunosuppression in Sepsis

Complement factor C5a was originally identified as a powerful promoter of inflammation through activation of the C5a receptor 1 (C5ar1). Recent evidence suggests involvement of C5a not only in pro- but also in anti-inflammatory signaling. The present study aims to unveil the role of C5ar1 as potential therapeutic target in a murine sepsis model. Our study discloses a significantly increased survival in models of mild to moderate but not severe sepsis of C5ar1-deficient mice. The decreased mortality of C5ar1-deficient mice is accompanied by improved pathogen clearance and largely preserved liver function. C5ar1-deficient mice exhibited a significantly increased production of the pro-inflammatory mediator interferon-γ (IFN-γ) and a decreased production of the anti-inflammatory cytokine interleukin-10 (IL-10). Together, these data uncover C5a signaling as a mediator of immunosuppressive processes during sepsis and describe the C5ar1 and related changes of the IFN-γ to IL-10 ratio as markers for the immunological (dys)function accompanying sepsis.

Long-acting nanoparticulate DNase-1 for effective suppression of SARS-CoV-2-mediated neutrophil activities and cytokine storm

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a new strain of coronavirus not previously identified in humans. Globally, the number of confirmed cases and mortality rates of coronavirus disease 2019 (COVID-19) have risen dramatically. Currently, there are no FDA-approved antiviral drugs and there is an urgency to develop treatment strategies that can effectively suppress SARS-CoV-2-mediated cytokine storms, acute respiratory distress syndrome (ARDS), and sepsis. As symptoms progress in patients with SARS-CoV-2 sepsis, elevated amounts of cell-free DNA (cfDNA) are produced, which in turn induce multiple organ failure in these patients. Furthermore, plasma levels of DNase-1 are markedly reduced in SARS-CoV-2 sepsis patients. In this study, we generated recombinant DNase-1-coated polydopamine-poly(ethylene glycol) nanoparticulates (named long-acting DNase-1), and hypothesized that exogenous administration of long-acting DNase-1 may suppress SARS-CoV-2-mediated neutrophil activities and the cytokine storm. Our findings suggest that exogenously administered long-acting nanoparticulate DNase-1 can effectively reduce cfDNA levels and neutrophil activities and may be used as a potential therapeutic intervention for life-threatening SARS-CoV-2-mediated illnesses.

Antibiotic-driven intestinal dysbiosis in pediatric short bowel syndrome is associated with persistently altered microbiome functions and gut-derived bloodstream infections

Surgical removal of the intestine, lifesaving in catastrophic gastrointestinal disorders of infancy, can result in a form of intestinal failure known as short bowel syndrome (SBS). Bloodstream infections (BSIs) are a major challenge in pediatric SBS management. BSIs require frequent antibiotic therapy, with ill-defined consequences for the gut microbiome and childhood health. Here, we combine serial stool collection, shotgun metagenomic sequencing, multivariate statistics and genome-resolved strain-tracking in a cohort of 19 patients with surgically-induced SBS to show that antibiotic-driven intestinal dysbiosis in SBS enriches for persistent intestinal colonization with BSI causative pathogens in SBS. Comparing the gut microbiome composition of SBS patients over the first 4 years of life to 19 age-matched term and 18 preterm controls, we find that SBS gut microbiota diversity and composition was persistently altered compared to controls. Commensals including Ruminococcus, Bifidobacterium, Eubacterium, and Clostridium species were depleted in SBS, while pathobionts (Enterococcus) were enriched. Integrating clinical covariates with gut microbiome composition in pediatric SBS, we identified dietary and antibiotic exposures as the main drivers of these alterations. Moreover, antibiotic resistance genes, specifically broad-spectrum efflux pumps, were at a higher abundance in SBS, while putatively beneficial microbiota functions, including amino acid and vitamin biosynthesis, were depleted. Moreover, using strain-tracking we found that the SBS gut microbiome harbors BSI causing pathogens, which can persist intestinally throughout the first years of life. The association between antibiotic-driven gut dysbiosis and enrichment of intestinal pathobionts isolated from BSI suggests that antibiotic treatment may predispose SBS patients to infection. Persistence of pathobionts and depletion of beneficial microbiota and functionalities in SBS highlights the need for microbiota-targeted interventions to prevent infection and facilitate intestinal adaptation.

Impact of a Best Practice Prevention Bundle on Central Line-associated Bloodstream Infection (CLABSI) Rates and Outcomes in Pediatric Hematology, Oncology, and Hematopoietic Cell Transplantation Patients in Inpatient and Ambulatory Settings

BACKGROUND

Pediatric hematology, oncology, and hematopoietic cell transplantation (HCT) patients are at increased risk for bloodstream infections. The authors sought to evaluate the influence of a standardized best practice central venous catheter (CVC) maintenance bundle on the burden of and risk factors for mucosal barrier injury (MBI) and non-MBI central line-associated bloodstream infections (CLABSIs) across a common inpatient and ambulatory continuum in this high-risk population.

METHODS

A retrospective cohort study of patients with underlying malignancy, hematologic disorders, and HCT recipients with a CVC in place at the time of CLABSI diagnosis in both inpatient and ambulatory settings from January 1, 2012 to December 31, 2016. Descriptive, nonparametric statistics were used to describe patient characteristics and outcomes. Logistic regression analyses were applied to identify potential risk factors for inpatient versus ambulatory and MBI versus non-MBI CLABSI.

RESULTS

During the 5-year period, 118 of 808 (14.6%) patients had 159 laboratory-confirmed CLABSIs for ambulatory and inpatient CLABSI rates of 0.27 CLABSI/1000 and 2.2 CLABSI/1000 CVC days, respectively. CLABSI occurred more frequently in hospitalized patients after HCT and with underlying leukemia, most frequently caused by Gram-negative bacteria. MBI CLABSI accounted for 42% of all CLABSI with a 3-fold higher risk in hospitalized patients. Having multiple CVC or a CVC that was not a port independently associated with higher CLABSI risk.

CONCLUSIONS

In our cohort, non-MBI CLABSI continued to account for the majority of CLABSI. CVC type is independently associated with higher overall CLABSI risk. Further studies are needed to reliably define additional prevention strategies when CLABSI maintenance bundles elements are optimized in this high-risk population.

Therapeutic Plasma Exchange Protects Patients with Sepsis-Associated Disseminated Intravascular Coagulation by Improving Endothelial Function

The mortality rate of sepsis-associated disseminated intravascular coagulation (DIC) is high. This study aimed to explore the efficacy of therapeutic plasma exchange (TPE) in sepsis-associated DIC patients by improving endothelial function. A total of 112 sepsis-associated DIC patients were randomly divided into the TPE group (n = 40), the heparin (HP) group (n = 36), and the SHAM group (n = 36). The SHAM group received conventional treatment; the HP group was treated with HP based on conventional treatment; and the TPE group received conventional treatment plus TPE. The differences in thromboelastogram (TEG), platelet (PLT), coagulation function, and the endothelial cell (EC) injury biomarkers at 6 h, 24 h, 48 h, 72 h, and 7 days after TPE were compared among the three groups, and the three groups were compared in terms of Acute Physiology and Chronic Health Evaluation II (APACHE II) score, Sepsis-Related Organ Failure Assessment (SOFA) score, the length of intensive care unit (ICU) hospitalization, 28-day mortality rate, 28-day cumulative survival rate, the incidence of bleeding events, the incidence of acute kidney injury (AKI), and acute respiratory distress syndrome (ARDS). The efficacy of TPE is superior to the HP in increasing PLT, improving coagulation function, increasing the 28-day cumulative survival rate, and reducing the length of ICU hospitalization, 28-day mortality, and the incidence of bleeding events, AKI, and ARDS with statistically significant differences (P < .05). Moreover, the effect of TPE outperforms HP on the EC injury biomarkers with statistically significant differences (P < .05). Our results suggest that TPE may be more effective than HP in the treatment of patients with sepsis-associated DIC. The possible mechanism is via improving endothelial function.

The role of phytochemicals in sepsis: A mechanistic and therapeutic perspective

Sepsis and septic shock are still a leading cause of mortality and morbidity in intensive care units worldwide. Sepsis is an uncontrolled and excessive response of the innate immune system toward the invading infectious microbes, characterized by the hyper-production of pro-inflammatory mediators such as interleukin (IL)-1β, IL-6, tumor-necrosis factor (TNF)-α, and high-mobility group box 1 (HMGB1). In severe sepsis, the overwhelming production of pro-inflammatory cytokines and reactive oxygen species may compromise organ function and lead to the induction of abnormal apoptosis in different organs, resulting in multiple organ dysfunction syndrome and death. Hence, compounds that are able to attenuate inflammatory responses may have therapeutic potential for sepsis treatment. Understanding the pathophysiology and underlying molecular mechanisms of sepsis may provide useful insights in the discovery and development of new effective therapeutics. Therefore, numerous studies have invested much effort into elucidating the mechanisms involved with the onset and development of sepsis. The present review mainly focuses on the molecules and signaling pathways involved in the pathogenicity of sepsis. Additionally, several well-known natural bioactive herbal compounds and phytochemicals, which have shown protective and therapeutic effects with regard to sepsis, as well as their mechanisms of action, are presented. This review suggests that these phytochemicals are able to attenuate the overwhelming inflammatory responses developed during sepsis by modulating different signaling pathways. Moreover, the anti-inflammatory and cytoprotective activities of phytochemicals make them potent compounds to be included as complementary therapeutic agents in the diets of patients suffering from sepsis in an effort to alleviate sepsis and its life-threatening complications, such as multi-organ failure.

Perinatal Gram-Positive Bacteria Exposure Elicits Distinct Cytokine Responses In Vitro

During pregnancy, infections caused by the gram-positive bacteria Enterococcus faecalis (E. faecalis), Streptococcus agalacticae (S. agalacticae), and Staphylococcus aureus (S. aureus) are major reasons for preterm labor, neonatal prematurity, meningitis, or sepsis. Here, we propose cytokine responses to bacterial infections by the immature perinatal immune system as central players in the pathogenesis of preterm birth and neonatal sepsis. We aimed to close the gap in knowledge about such cytokine responses by stimulating freshly isolated umbilical blood mononuclear cells (UBMC) with lysates of E. faecalis, S. agalacticae, and S. aureus collected from pregnant women in preterm labor. Bacterial lysates and, principally, S. aureus and S. agalacticae distinctly triggered most of the eleven inflammatory, anti-inflammatory, TH₁/TH₂ cytokines, and chemokines quantified in UBMC culture media. Chemokines depicted the most robust induction. Among them, MIP-1β was further enhanced in UBMC from female compered to male newborn infants. Due to its stability and high levels, we investigated the diagnostic value of IL-8. IL-8 was critically upregulated in cord blood of preterm neonates suffering from infections compared to gestational age-matched controls. Our results provide novel clues about perinatal immunity, underscoring a potential value of IL-8 for the timely detection of infections and suggesting that MIP-1β constitutes an early determinant of sex-specific immunity, which may contribute, e.g., to male’s vulnerability to preterm birth.

Incidence of sepsis and associated mortality within the first year after cancer diagnosis in middle aged adults: A US population based study

Background

The incidence of sepsis has been rising overall but updated data in cancer patients are lacking. After a cancer diagnosis, incidence of sepsis and overall mortality peak within the first year. However, how much sepsis contributes to mortality remains unclear. We used a multistate model approach to analyze the incidence, risk factors and associated mortality of sepsis within 1 year of cancer diagnosis in middle aged adults.

Methods

Analysis of a large US health insurance claims database (Marketscan) between 2005 and 2014. Patients with a new diagnosis of cancer who received chemotherapy were included. Within a year of diagnosis, we assessed inpatient admissions for sepsis based on ICD-9 codes and survival using hospitalizations, outpatient visits and prescriptions filled. Competing risk and multistate models were used to assess the incidence of sepsis and transition probabilities between cancer, sepsis and death.

Results

119,379 patients (38.9% males), aged 55 (50–60) years, were included; 2,560 developed isolated sepsis, 477 severe sepsis and 1331 septic shock within 1 year, with associated hospital mortality of 14.8%, 30% and 46% respectively. The probability of sepsis increased between 2005 and 2014; at 1 year, its cumulative incidence was 3.7% with a probability of mortality after sepsis of 35.5% (95% CI 21.6%-50.9%). Age, male gender, Charlson comorbidity index, hematological malignancies and metastases at diagnosis were associated with sepsis and mortality.

Conclusions

Incidence and mortality of sepsis were 3.7% and 35.5% at 1 year after cancer diagnosis and were both associated with baseline patient and cancer characteristics.

Vitamin C-An Adjunctive Therapy for Respiratory Infection, Sepsis and COVID-19

There are limited proven therapies for COVID-19. Vitamin C's antioxidant, anti-inflammatory and immunomodulating effects make it a potential therapeutic candidate, both for the prevention and amelioration of COVID-19 infection, and as an adjunctive therapy in the critical care of COVID-19. This literature review focuses on vitamin C deficiency in respiratory infections, including COVID-19, and the mechanisms of action in infectious disease, including support of the stress response, its role in preventing and treating colds and pneumonia, and its role in treating sepsis and COVID-19. The evidence to date indicates that oral vitamin C (2-8 g/day) may reduce the incidence and duration of respiratory infections and intravenous vitamin C (6-24 g/day) has been shown to reduce mortality, intensive care unit (ICU) and hospital stays, and time on mechanical ventilation for severe respiratory infections. Further trials are urgently warranted. Given the favourable safety profile and low cost of vitamin C, and the frequency of vitamin C deficiency in respiratory infections, it may be worthwhile testing patients' vitamin C status and treating them accordingly with intravenous administration within ICUs and oral administration in hospitalised persons with COVID-19.

Sepsis and Coronavirus Disease 2019: Common Features and Anti-Inflammatory Therapeutic Approaches

Great efforts are being made worldwide to identify the specific clinical characteristics of infected critically ill patients that mediate the associated pathogenesis, including vascular dysfunction, thrombosis, dysregulated inflammation, and respiratory complications. Recently, coronavirus disease 2019 has been closely related to sepsis, which suggests that most deaths in ICUs in infected patients are produced by viral sepsis. Understanding the physiopathology of the disease that lead to sepsis after severe acute respiratory syndrome coronavirus 2 infection is a current clinical need to improve intensive care-applied therapies applied to critically ill patients. Although the whole representative data characterizing the immune and inflammatory status in coronavirus disease 2019 patients are not completely known, it is clear that hyperinflammation and coagulopathy contribute to disease severity. Here, we present some common features shared by severe coronavirus disease 2019 patients and sepsis and describe proposed anti-inflammatory therapies for coronavirus disease 2019 which have been previously evaluated in sepsis.

Deep learning-based clustering robustly identified two classes of sepsis with both prognostic and predictive values

BACKGROUND

Sepsis is a heterogenous syndrome and individualized management strategy is the key to successful treatment. Genome wide expression profiling has been utilized for identifying subclasses of sepsis, but the clinical utility of these subclasses was limited because of the classification instability, and the lack of a robust class prediction model with extensive external validation. The study aimed to develop a parsimonious class model for the prediction of class membership and validate the model for its prognostic and predictive capability in external datasets.

METHODS

The Gene Expression Omnibus (GEO) and ArrayExpress databases were searched from inception to April 2020. Datasets containing whole blood gene expression profiling in adult sepsis patients were included. Autoencoder was used to extract representative features for k-means clustering. Genetic algorithms (GA) were employed to derive a parsimonious 5-gene class prediction model. The class model was then applied to external datasets (n = 780) to evaluate its prognostic and predictive performance.

FINDINGS

A total of 12 datasets involving 1613 patients were included. Two classes were identified in the discovery cohort (n = 685). Class 1 was characterized by immunosuppression with higher mortality than class 2 (21.8% [70/321] vs. 12.1% [44/364]; p < 0.01 for Chi-square test). A 5-gene class model (C14orf159, AKNA, PILRA, STOM and USP4) was developed with GA. In external validation cohorts, the 5-gene class model (AUC: 0.707; 95% CI: 0.664 - 0.750) performed better in predicting mortality than sepsis response signature (SRS) endotypes (AUC: 0.610; 95% CI: 0.521 - 0.700), and performed equivalently to the APACHE II score (AUC: 0.681; 95% CI: 0.595 - 0.767). In the dataset E-MTAB-7581, the use of hydrocortisone was associated with increased risk of mortality (OR: 3.15 [1.13, 8.82]; p = 0.029) in class 2. The effect was not statistically significant in class 1 (OR: 1.88 [0.70, 5.09]; p = 0.211).

INTERPRETATION

Our study identified two classes of sepsis that showed different mortality rates and responses to hydrocortisone therapy. Class 1 was characterized by immunosuppression with higher mortality rate than class 2. We further developed a 5-gene class model to predict class membership.

FUNDING

The study was funded by the National Natural Science Foundation of China (Grant No. 81,901,929).

Procalcitonin as an early indicator of urosepsis following prostate biopsy

BACKGROUND

To investigate the usefulness of serum procalcitonin (PCT) in the early diagnosis of urinary tract infection (UTI) and urosepsis following transrectal prostate biopsy.

METHODS

In this prospective observational study, 227 patients who underwent transrectal ultrasound-guided prostate biopsy were evaluated. The relationship between urosepsis and age, serum PCT, C-reactive protein, prostate-specific antigen (PSA), prostate volume, PSA density and pathologic results following biopsy was assessed. Serum PCT level was measured in all patients immediately before the biopsy and at the post-biopsy day 2.

RESULTS

Of the 227 patients, 11 (4.8%) developed UTI with positive urine culture without urosepsis and 5 (2.2%) developed urosepsis within 30 days after biopsy. The concentration of PCT was within the normal range before the biopsy. Procalcitonin concentration at post-biopsy day 2 was significantly higher in patients who developed urosepsis (1.91 ± 2.99 ng/ml vs. 0.05 ± 0.08 ng/ml; p = .004) compared with non-UTI patients. Only elevated PCT level at post-biopsy day 2 was a statistically significant independent predictor of post-biopsy urosepsis. The area under the ROC curve for the prediction of urosepsis was 0.976 (95%CI: 0.941-1.000) and a cut-off 0.095 ng/ml in the level of PCT at post-biopsy day 2 yielded a sensitivity of 100% and specificity of 93.8% in detecting urosepsis following biopsy.

CONCLUSIONS

Procalcitonin appears to be a useful early biomarker to predict the urosepsis following prostate biopsy. Patients with elevated PCT value should be closely monitored after the biopsy.

Severe Maternal Outcomes Associated with Abortion-Related Sepsis at the Obafemi Awolowo University Teaching Hospitals Complex (OAUTHC), Ile-Ife, Nigeria: Experience from the Last Decade of Millennium Development Goal Era

BACKGROUND

Abortion-related sepsis contributes significantly to reproductive morbidity and preventable mortality in Nigeria. Effective strategies to combat the associated Severe Maternal Outcomes (SMO) requires reliable statistics and an understanding of the immediate contributors.

METHODS

A retrospective review of women managed for abortion-related sepsis between September, 2006 and August, 2015 at the Obafemi Awolowo University Teaching Hospitals Complex (OAUTHC), Ile-Ife, Nigeria. The socio-demographic characteristics, pattern of presentation, reasons for termination of pregnancy and clinical outcomes were analysed. Life-threatening complication rate, mortality index and maternal mortality ratio were determined using the WHO "Near-Miss" concept.

RESULTS

Overall, 128 women were managed for abortion-related sepsis, with 11,565 live births within the decade. Eighty (79.6%) of the 88 women with induced abortions were not on contraception, though pregnancy was not desired. Interference with education, paternity dispute and short inter-pregnancy interval were the commonest reasons for pregnancy termination. Near-misses were recorded in 67.5% of the women, especially anaemia requiring at least 4units of blood and laparotomy for non-caesarean indications. The mortality-index and case fatality rate were 13.9% and 9.4% respectively, predominantly due to multiple organ dysfunction from overwhelming sepsis.

CONCLUSION

The life-threatening complication rate and mortality index associated with abortion-related sepsis at the OAUTHC remain bothersome, with a 1:7.5 chance of mortality once diagnosed. The maternal near-misses identified in this study would serve as alert signals to Physicians on the risk of maternal death in these women. Strategies should be implemented to facilitate access to contraception, standardised abortion-related services and hospital-based interventions to care for maternal near-misses.

A cross-sectional analysis of variables associated with morbidity and mortality in postoperative neurosurgical patients diagnosed with sepsis

BACKGROUND

Sepsis is a systemic, inflammatory response to infection associated with significant morbidity and mortality. There is a considerable lack of literature exploring sepsis in neurosurgery. We aimed to identify variables that were correlated with mortality and increased morbidity as defined by readmission and increased length of stay in postoperative neurosurgical patients that met a sepsis diagnosis.

METHODS

A retrospective chart review was conducted of 105 patients who underwent a neurosurgical operation at our institution from 2012 to 2017 who were discharged with at least one sepsis diagnosis code and who did not have a preoperative infection. We identified variables that were correlated with mortality, readmission, and increased length of stay.

RESULTS

Patients who survived were preferentially distributed towards lower ASA Physical Status Classification scores. A larger percentage of patients who did not survive had cranial surgery, whereas patients who survived were more likely to have undergone spinal surgery. Higher respiratory rates, higher maximum lactic acid levels, positive sputum cultures, and lower incoming Glasgow Coma Scores (GCS) were significantly correlated with mortality. A larger fraction of readmitted patients had positive surgical site cultures but had negative sputum cultures. Length of hospitalization was correlated with incoming GCS, non-elective operations, and Foley catheter, arterial line, central line, and endotracheal tube duration.

CONCLUSIONS

Neurosurgical postoperative patients diagnosed with sepsis may be risk stratified for mortality, readmission, and increased length of stay based on certain variables that may help direct their care. Further prospective studies are needed to explore causal relationships.

Critical Care of Hematopoietic Stem Cell Transplant Patients

Life-threatening complications are frequent after hematopoietic stem cell transplant (HSCT), and optimum critical care is essential to ensuring good outcomes. The immunologic consequences of HSCT result in a markedly different host response to critical illness. Infection is the most common cause of critical illness but noninfectious complications are frequent. Respiratory failure or sepsis are the typical presentations but the sequelae of HSCT can affect nearly any organ system. Pattern recognition can facilitate anticipation and early intervention in post-HSCT critical illness. HSCT critical care is a multidisciplinary endeavor. Continued investigation and focus on process improvement will continue to improve outcomes.

COVID-19-Associated Systemic Thromboembolism: A Case Report and Review of the Literature

INTRODUCTION

Coronavirus disease 2019 (COVID-19) is a pandemic that has affected >188 countries, involved >24 million people, and caused >840,000 deaths. COVID-19, in its severe form, presents as acute respiratory distress syndrome (ARDS), shock, and multiorgan failure. Thrombotic microangiopathy of the lungs and kidneys has been observed in these patients. Elevated D-dimer levels have been observed in people with serious COVID-19 illness, and this could be helpful in guiding treatment with anticoagulation in these patients.

OBJECTIVE

To analyze the role of anticoagulation as a treatment modality for COVID-19.

METHODS

We present the unique case of a COVID-19 patient who developed sepsis, ARDS, acute kidney injury, and deep-vein thrombosis (DVT), who was deteriorating clinically. She was treated with anticoagulation.

RESULTS

There was rapid recovery after treatment with systemic anticoagulation.

CONCLUSIONS

Systemic anticoagulation could prove to be essential in the treatment of CO-VID-19. Further studies are required to assess its role in improving long-term morbidity and mortality in these patients.

Crusted scabies in an elderly woman

Crusted scabies is a highly contagious variant of classic scabies. Affected individuals are often elderly or immunocompromised and disease is associated with significant morbidity and mortality. Herein, we report an elderly woman residing in an assisted living facility who presented with diffuse sand-on-skin scale on her trunk, proximal extremities, scalp, hands, and feet. She was diagnosed with crusted scabies, isolated from other patients, and subsequently treated with permethrin 5% lotion and ivermectin. She died two weeks after initial presentation owing to sepsis.

IsdB antibody-mediated sepsis following S. aureus surgical site infection

Staphylococcus aureus is prevalent in surgical site infections (SSI) and leads to death in approximately 1% of patients. Phase IIB/III clinical trial results have demonstrated that vaccination against the iron-regulated surface determinant protein B (IsdB) is associated with an increased mortality rate in patients with SSI. Thus, we hypothesized that S. aureus induces nonneutralizing anti-IsdB antibodies, which facilitate bacterial entry into leukocytes to generate "Trojan horse" leukocytes that disseminate the pathogen. Since hemoglobin (Hb) is the primary target of IsdB, and abundant Hb-haptoglobin (Hb-Hp) complexes in bleeding surgical wounds are normally cleared via CD163-mediated endocytosis by macrophages, we investigated this mechanism in vitro and in vivo. Our results demonstrate that active and passive IsdB immunization of mice renders them susceptible to sepsis following SSI. We also found that a multimolecular complex containing S. aureus protein A-anti-IsdB-IsdB-Hb-Hp mediates CD163-dependent bacterial internalization of macrophages in vitro. Moreover, IsdB-immunized CD163-/- mice are resistant to sepsis following S. aureus SSI, as are normal healthy mice given anti-CD163-neutralizing antibodies. These genetic and biologic CD163 deficiencies did not exacerbate local infection. Thus, anti-IsdB antibodies are a risk factor for S. aureus sepsis following SSI, and disruption of the multimolecular complex and/or CD163 blockade may intervene.

The systemic inflammatory response syndrome in acute antipsychotic poisoning

The purpose of this study was to investigate the mutual effect of systemic inflammatory response syndrome (SIRS) accompanied with fibrinolysis, endotoxemia, and coagulation in severe cases of antipsychotic poisoning. A total of 199 patients were examined, of which 71 were men and 128 were women. The age of the patients was from 22 to 63 years, (45.3 ± 6.1 years on average). According to the results of the course of therapy, the patients were divided into two groups. In the blood plasma, the content of C-reactive protein, fibrinogen and its proteolysis products (oligopeptides, D-dimers), interleukin-6 were determined. In the first 1 to 3 days, in group 1, the level of interleukin-6 decreased and approached the normal level (P ≤ .05). The opposite trend continued throughout the observation of patients from group 2-their levels of interleukin-6 increased day by day (P ≤ .05). The concentration of D-dimer already in 1 day after admission to intensive care in patients from group 2 exceeded the norm by 14 times (P ≤ .05). The level of D-dimer correlated with the level of oligopeptides in blood plasma upon admission, as well as for 3 and 5 days after admission to intensive care: 0.36, 0.76 at P ≤ .05, 0.94 at P ≤ .01, respectively. Similar correlations were obtained for the content of oligopeptides in urine and the level of D-dimer: 0.55, 0.85 at P ≤ .05, 0.93 at P ≤ .01. In this regard, the most pronounced correlation is that between the SIRS score, plasma D-dimer level, and the plasma level of the D-dimer derivatives, oligopeptides.

Single-cell deconstruction of post-sepsis skeletal muscle and adipose tissue microenvironments

BACKGROUND

Persistent loss of skeletal muscle mass and function as well as altered fat metabolism are frequently observed in severe sepsis survivors. Studies examining sepsis-associated tissue dysfunction from the perspective of the tissue microenvironment are scarce. In this study, we comprehensively assessed transcriptional changes in muscle and fat at single-cell resolution following experimental sepsis induction.

METHODS

Skeletal muscle and visceral white adipose tissue from control mice or mice 1 day or 1 month following faecal slurry-induced sepsis were used. Single cells were mechanically and enzymatically prepared from whole tissue, and viable cells were further isolated by fluorescence activated cell sorting. Droplet-based single-cell RNA-sequencing (scRNA-seq; 10× Genomics) was used to generate single-cell gene expression profiles of thousands of muscle and fat-resident cells. Bioinformatics analyses were performed to identify and compare individual cell populations in both tissues.

RESULTS

In skeletal muscle, scRNA-seq analysis classified 1438 single cells into myocytes, endothelial cells, fibroblasts, mesenchymal stem cells, macrophages, neutrophils, T-cells, B-cells, and dendritic cells. In adipose tissue, scRNA-seq analysis classified 2281 single cells into adipose stem cells, preadipocytes, endothelial cells, fibroblasts, macrophages, dendritic cells, B-cells, T-cells, NK cells, and gamma delta T-cells. One day post-sepsis, the proportion of most non-immune cell populations was decreased, while immune cell populations, particularly neutrophils and macrophages, were highly enriched. Proportional changes of endothelial cells, neutrophils, and macrophages were validated using faecal slurry and cecal ligation and puncture models. At 1 month post-sepsis, we observed persistent enrichment/depletion of cell populations and further uncovered a cell-type and tissue-specific ability to return to a baseline transcriptomic state. Differential gene expression analyses revealed key genes and pathways altered in post-sepsis muscle and fat and highlighted the engagement of infection/inflammation and tissue damage signalling. Finally, regulator analysis identified gonadotropin-releasing hormone and Bay 11-7082 as targets/compounds that we show can reduce sepsis-associated loss of lean or fat mass.

CONCLUSIONS

These data demonstrate persistent post-sepsis muscle and adipose tissue disruption at the single-cell level and highlight opportunities to combat long-term post-sepsis tissue wasting using bioinformatics-guided therapeutic interventions.

Rectal Perforation by an Intrauterine Device Leading to Fatal Intra-Abdominal Sepsis and Necrotizing Fasciitis

BACKGROUND

Colorectal injury from an intrauterine device (IUD) is rare but may lead to major complications.

CASE

A 55-year-old woman presented to a tertiary care hospital with 4 days of generalized weakness, confusion, dysuria, and lower back pain. She provided a vague history of an unsuccessful attempt to remove an IUD 30 years prior. A computed tomography scan demonstrated an IUD in the rectal lumen, with gluteal and pelvic gas and fluid collections. Emergency surgery found necrotizing fasciitis. Despite multiple debridements, sigmoidoscopic IUD removal, and long-term intravenous antibiotics, the patient died from sepsis and multiorgan failure.

CONCLUSION

IUDs require proper monitoring and timely removal to prevent potential complications associated with organ perforation.

COVID-19 Patients Upregulate Toll-like Receptor 4-mediated Inflammatory Signaling That Mimics Bacterial Sepsis

BACKGROUND

Observational studies of the ongoing coronavirus disease 2019 (COVID-19) outbreak suggest that a 'cytokine storm' is involved in the pathogenesis of severe illness. However, the molecular mechanisms underlying the altered pathological inflammation in COVID-19 are largely unknown. We report here that toll-like receptor (TLR) 4-mediated inflammatory signaling molecules are upregulated in peripheral blood mononuclear cells (PBMCs) from COVID-19 patients, compared with healthy controls (HC).

METHODS

A total of 48 subjects including 28 COVID-19 patients (8 severe/critical vs. 20 mild/moderate cases) admitted to Chungnam National University Hospital, and age/sex-matched 20 HC were enrolled in this study. PBMCs from the subjects were processed for nCounter Human Immunology gene expression assay to analyze the immune related transcriptome profiles. Recombinant proteins of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) were used to stimulate the PBMCs and monocyte-derived macrophages, and real-time polymerase chain reaction was performed to quantify the mRNA expressions of the pro-inflammatory cytokines/chemokines.

RESULTS

Among the most highly increased inflammatory mediators in severe/critically ill patients, S100A9, an alarmin and TLR4 ligand, was found as a noteworthy biomarker, because it inversely correlated with the serum albumin levels. We also observed that recombinant S2 and nucleocapsid proteins of SARS-CoV-2 significantly increased pro-inflammatory cytokines/chemokines and S100A9 in human primary PBMCs.

CONCLUSION

These data support a link between TLR4 signaling and pathological inflammation during COVID-19 and contribute to develop therapeutic approaches through targeting TLR4-mediated inflammation.

Relationships between predischarge and postdischarge infectious complications, length of stay, and unplanned readmissions in the ACS NSQIP database

BACKGROUND

Postoperative complications, length of index hospital stay, and unplanned hospital readmissions are important metrics reflecting surgical care quality. Postoperative infections represent a substantial proportion of all postoperative complications. We examined the relationships between identification of postoperative infection prehospital and posthospital discharge, length of stay, and unplanned readmissions in the American College of Surgeons National Surgical Quality Improvement Program database across nine surgical specialties.

METHODS

The 30-day postoperative infectious complications including sepsis, surgical site infections, pneumonia, and urinary tract infection were analyzed in the American College of Surgeons National Surgical Quality Improvement Program inpatient data during the period from 2012 to 2017. General, gynecologic, vascular, orthopedic, otolaryngology, plastic, thoracic, urologic, and neurosurgical inpatient operations were selected.

RESULTS

Postoperative infectious complications were identified in 5.2% (137,014/2,620,450) of cases; 81,929 (59.8%) were postdischarge. The percentage of specific complications identified postdischarge were 73.4% of surgical site infections (range across specialties 63.7-93.1%); 34.9% of sepsis cases (27.4-58.1%); 26.5% of pneumonia cases (18.9%-36.3%); and 53.2% of urinary tract infections (48.3%-88.0%). The relative risk of readmission among patients with postdischarge versus predischarge surgical site infection, sepsis, pneumonia, or urinary tract infection was 5.13 (95% confidence interval: 4.90-5.37), 9.63 (8.93-10.40), 10.79 (10.15-11.45), and 3.32 (3.07-3.60), respectively. Over time, mean length of stay decreased but postdischarge infections and readmission rates significantly increased.

CONCLUSION

Most postoperative infectious complications were diagnosed postdischarge. These were associated with an increased risk of readmission. The trend toward shorter length of stay over time was observed along with an increase both in the percentage of infections detected after discharge and the rate of unplanned related postoperative readmissions over time. Postoperative surveillance of infections should extend beyond hospital discharge of surgical patients.

Epidemiology of Bloodstream Infections in Hospitalized Children in the United States, 2009-2016

BACKGROUND

Bloodstream infections (BSIs) cause significant morbidity and mortality in children. Recent pediatric epidemiological data may inform prevention strategies and empiric antimicrobial therapy selection.

METHODS

We conducted a retrospective cohort study from 2009 through 2016 utilizing demographic and microbiologic data on inpatients aged <19 years using the Premier Healthcare Database. BSIs were positive blood cultures without known contaminants. Hospitalization rate was the number of BSI-positive encounters per 1000 admissions. Community-acquired infections (CAIs) were cultures positive ≤2 days of admission among nonneonates. BSI patients were compared to documented positive BSI patients (non-BSI); differences were analyzed using χ2 test, t test, and Cochran-Armitage test for time trends.

RESULTS

Among 1 809 751 encounters from 162 US hospitals, 5340 (0.30%) were BSI positive; CAIs were most common (50%). BSI patients were more often aged 1-5 years and had complex chronic conditions or central lines compared to non-BSI patients. The BSI hospitalization rate declined nonsignificantly over time (3.13 in 2009 to 2.98 in 2016, P = .08). Among pathogens, Escherichia coli (0.80 to 1.26), methicillin-sensitive Staphylococcus aureus (0.83 to 1.98), and group A Streptococcus (0.16 to 0.37) significantly increased for nonneonates, while Streptococcus pneumoniae (1.07 to 0.26) and Enterococcus spp. (0.60 to 0.17) declined. Regional differences were greatest for E. coli and highest in the New England and South Atlantic regions.

CONCLUSIONS

Trends in pediatric BSI hospitalization rates varied by pathogen and regionally. Overall the BSI hospitalization rate did not significantly decline, indicating a continued need to improve pediatric BSI assessment and prevention.

Procalcitonin-guided antibiotic therapy for suspected and confirmed sepsis of patients in a surgical trauma ICU: a prospective, two period cross-over, interventional study

BACKGROUND

Biomarkers like procalcitonin (PCT) are an important antimicrobial stewardship tool for critically ill patients. There is little evidence regarding the use of PCT-guided antibiotic algorithms in developing countries. Evidence is also lacking for PCT-based antibiotic algorithms in surgical trauma patients admitted to the intensive care unit (ICU).

METHODS

A prospective, two period cross-over study was conducted in a surgical trauma intensive care unit in South Africa. In the first period, 40 patients were recruited into the control group and antibiotics were discontinued as per standard of care. In the second period, 40 patients were recruited into the procalcitonin group and antibiotics were discontinued if the PCT decreased by ≥ 80% from the peak PCT level, or to an absolute value of less than 0.5 μg/L. Antibiotic duration of treatment was the primary outcome. Patients were followed up for 28 days from the first sepsis event.

RESULTS

For the first sepsis event the PCT group had a mean antibiotic duration of 9.3 days while the control group had a mean duration of 10.9 days (p = 0.10). Patients in the intervention group had higher mean (SD) antibiotic free days alive of 7.7 (6.57) days compared to the control group mean (SD) of 3.8 (5.22) days, (p = 0.004). In-hospital mortality rate was lower in the intervention group (15%) compared to the control group (30%) and was statistically significant (p = 0.045).

CONCLUSION

There was no significant difference in duration of antibiotic treatment between the two groups. However, the PCT group had more antibiotic free days alive and lower in-hospital mortality compared to the control group.