Platelets Are Critical Key Players in Sepsis

Enhancing insight into ferroptosis mechanisms in sepsis: A genomic and pharmacological approach integrating single-cell sequencing and Mendelian randomization

This research investigated the intricate relationship between ferroptosis and sepsis by utilizing advanced genomic and pharmacological methodologies. Specifically, we obtained expression quantitative trait loci (eQTLs) for 435 genes associated with ferroptosis from the eQTLGen Consortium and detected notable cis-eQTLs for 281 of these genes. Next, we conducted a detailed analysis to assess the impact of these eQTLs on susceptibility to sepsis using Mendelian randomization (MR) with data from a cohort of 10,154 sepsis patients and 452,764 controls sourced from the UK Biobank. MR analysis revealed 16 ferroptosis-related genes that exhibited significant associations with sepsis outcomes. To bolster the robustness of these findings, sensitivity analyses were performed to assess pleiotropy and heterogeneity, thus confirming the reliability of the causal inferences. Furthermore, single-cell RNA sequencing data from sepsis patients offered a detailed examination of gene expression profiles, demonstrating varying levels of ferroptosis marker expression across different cell types. Pathway enrichment analysis utilizing gene set enrichment analysis (GSEA) further revealed the key biological pathways involved in the progression of sepsis. Additionally, the use of computational molecular docking facilitated the prediction of interactions between identified genes and potential therapeutic compounds, highlighting novel drug targets. In conclusion, our integrated approach combining genomics and pharmacology offers valuable insights into the involvement of ferroptosis in sepsis, laying the groundwork for potential therapeutic strategies targeting this cell death pathway to enhance sepsis management.

Accelerated Severity of Illness Score Enhances Prediction of Complicated Acute Hematogenous Osteomyelitis in Children

BACKGROUND

Severity of illness determination for children with acute hematogenous osteomyelitis should be accomplished during the earliest stages of evaluation to guide treatment and establish prognosis. This study objectively defines an outcome of complicated osteomyelitis and explores an illness severity-based model with an improved ability to predict this outcome as soon and accurately as possible, comparing it to existing models.

METHODS

Children with Staphylococcus aureus acute hematogenous osteomyelitis (n = 438) were retrospectively studied to identify adverse events and predictors of severity. The outcome of complicated osteomyelitis was ultimately defined as the occurrence of any major or at least 3 minor adverse events, which occurred in 52 children. Twenty-four clinical and laboratory predictors were evaluated through univariate and stacked multivariable regression analyses of chronologically distinct groups of variables. Receiver operating characteristic curve analyses were conducted to compare models.

RESULTS

Accelerated Severity of Illness Score included: triage tachycardia [odds ratio: 10.2 (95% confidence interval: 3.48-32.3], triage tachypnea [6.0 (2.4-15.2)], C-reactive proteininitial ≥17.2 mg/dL [4.5 (1.8-11.8)], white blood cell count band percentageinitial >3.8% [4.6 (2.0-11.0)], hemoglobininitial ≤10.4 g/dL [6.0 (2.6-14.7)], methicillin-resistant S. aureus [3.0 (1.2-8.5)], septic arthritis [4.5 (1.8-12.3)] and platelet nadir [7.2 (2.7-20.4)]. The receiver operating characteristic curve of Accelerated Severity of Illness Score [area under the curve = 0.96 (0.941-0.980)] were superior to those of Modified Severity of Illness Score = 0.903 (0.859-0.947), Acute Score for Complications of Osteomyelitis Risk Evaluation = 0.878 (0.830-0.926) and Chronic Score for Complications of Osteomyelitis Risk Evaluation = 0.858 (0.811-0.904). Successive receiver operating characteristic curve analyses established an exponentially increasing risk of complicated osteomyelitis for children with mild (0/285 or 0%), moderate (4/63 or 6.3%), severe (15/50 or 30.0%) and hyper-severe (33/40 or 82.5%) acute hematogenous osteomyelitis (P<0.0001).

CONCLUSIONS

This study improves upon previous severity of illness models by identifying early predictors of a rigorously defined outcome of complicated osteomyelitis.

Persistent inflammation and lymphopenia and weaning outcomes of patients with prolonged mechanical ventilation

BACKGROUND

Weaning outcomes of patients receiving mechanical ventilation (MV) are affected by multiple factors. A clinical feature of critically ill patients is the presence of lymphopenia, however the clinical significance of lymphopenia in patients receiving prolonged MV remains unclear.

METHODS

We enrolled patients who received at least 21 consecutive days of MV in a medical center in Taiwan between 2007 and 2016. Patients with and without lymphopenia (mean count <1000/μL) were compared after propensity score matching.

RESULTS

Of the 3460 patients included in the analysis, 1625 (47.0%) were liberated from MV within 100 days. Lymphopenia and severe lymphopenia (mean count <500/μL) during the first 21 days of MV were common (52.9% and 14.5%, respectively), and restricted cubic spline analysis showed a significant reduction in weaning success when the lymphocyte count dropped below 1000/μL. After propensity score matching, the patients with lymphopenia during the third week had a lower rate of weaning success within 100 days (p = 0.005) and a higher in-hospital mortality rate (p = 0.001) than those without lymphopenia. The lymphopenia group also had significantly reduced platelet (p < 0.001) and albumin (p < 0.001) levels.

CONCLUSIONS

Our findings suggest that lymphopenia during the first 3 weeks may be a marker of poor weaning outcomes in patients with prolonged MV.

Platelet Storage-Problems, Improvements, and New Perspectives

Platelet transfusions are routine procedures in clinical treatment aimed at preventing bleeding in critically ill patients, including those with cancer, undergoing surgery, or experiencing trauma. However, platelets are susceptible blood cells that require specific storage conditions. The availability of platelet concentrates is limited to five days due to various factors, including the risk of bacterial contamination and the occurrence of physical and functional changes known as platelet storage lesions. In this article, the problems related to platelet storage lesions are categorized into four groups depending on research areas: storage conditions, additive solutions, new testing methods for platelets (proteomic and metabolomic analysis), and extensive data modeling of platelet production (mathematical modeling, statistical analysis, and artificial intelligence). This article provides extensive information on the challenges, potential improvements, and novel perspectives regarding platelet storage.

Continuous renal replacement therapy with vitamin E-coated polysulfone hemofilter reduces inflammatory responses in a porcine lipopolysaccharide-treated model

INTRODUCTION

Biological invasions may promote the onset of systemic inflammatory response syndrome in patients eligible for continuous renal replacement therapy (CRRT), leading to poor prognosis. Hence, we aimed to examine the inflammatory reactions in circulation using vitamin E-coated polysulfone hollow fiber membrane (ViLIFE).

METHODS

Lipopolysaccharides were intravenously administered to pigs (2 μg/kg/30 min) to establish an acute inflammation model. Extracorporeal circulation was performed for 6 h in continuous venovenous hemodiafiltration mode using a hemofilter for CRRT filled with a polysulfone hollow fiber membrane or ViLIFE, and the differences in inflammatory reactions were evaluated.

RESULTS

The ViLIFE group exhibited low platelet and cytokine levels (p < 0.05 vs. sham-CRRT group). Additionally, the ViLIFE group had lower lactate and high mobility group box 1 levels than the other groups.

CONCLUSION

ViLIFE represents a promising CRRT modality that can inhibit the inflammatory response in circulation and inhibit further biological invasions.

Association between systemic inflammation biomarkers and mortality in patients with sepsis-associated acute kidney injury receiving intensive care and continuous kidney replacement therapy: results from the RENERGY (REsearches for NEphRology and epidemioloGY) study

BACKGROUND

Identifying risk factors and improving prognostication for mortality among patients with sepsis-associated acute kidney injury (AKI) undergoing continuous kidney replacement therapy (CKRT) is important in improving the adverse prognosis of this patient population. This study aimed to compare the prognostic value of existing systemic inflammation biomarkers and determine the optimal systemic inflammation biomarker in patients with sepsis-associated AKI receiving CKRT.

METHODS

This multi-center, retrospective, observational cohort study included 1,500 patients with sepsis-associated AKI treated with intensive care and CKRT. The main predictor was a panel of 13 different systemic inflammation biomarkers. The primary outcome was 28-day mortality after CKRT initiation. Secondary outcomes included 90-day mortality after CKRT initiation, CKRT duration, kidney replacement therapy dependence at discharge, and lengths of intensive care unit (ICU) and hospital stays.

RESULTS

When added to the widely accepted Acute Physiology and Chronic Health Evaluation II score, platelet-to-albumin ratio (PAR) and neutrophil-platelet score (NPS) had the highest improvements in prognostication of 28-day mortality, where the corresponding increases in C-statistic were 0.01 (95% confidence interval [CI], 0.00-0.02) and 0.02 (95% CI, 0.01-0.03). Similar findings were observed for 90-day mortality. The 28- and 90-day mortality rates were significantly lower for the higher PAR and NPS quartiles. These associations remained significant even after adjustment for potential confounding variables in multivariable Cox proportional hazards models.

CONCLUSION

Of the available systemic inflammation biomarkers, the addition of PAR or NPS to conventional ICU prediction models improved the prognostication of patients with sepsis-associated AKI receiving intensive care and CKRT.

Deciphering Abnormal Platelet Subpopulations in COVID-19, Sepsis and Systemic Lupus Erythematosus through Machine Learning and Single-Cell Transcriptomics

This study focuses on understanding the transcriptional heterogeneity of activated platelets and its impact on diseases such as sepsis, COVID-19, and systemic lupus erythematosus (SLE). Recognizing the limited knowledge in this area, our research aims to dissect the complex transcriptional profiles of activated platelets to aid in developing targeted therapies for abnormal and pathogenic platelet subtypes. We analyzed single-cell transcriptional profiles from 47,977 platelets derived from 413 samples of patients with these diseases, utilizing Deep Neural Network (DNN) and eXtreme Gradient Boosting (XGB) to distinguish transcriptomic signatures predictive of fatal or survival outcomes. Our approach included source data annotations and platelet markers, along with SingleR and Seurat for comprehensive profiling. Additionally, we employed Uniform Manifold Approximation and Projection (UMAP) for effective dimensionality reduction and visualization, aiding in the identification of various platelet subtypes and their relation to disease severity and patient outcomes. Our results highlighted distinct platelet subpopulations that correlate with disease severity, revealing that changes in platelet transcription patterns can intensify endotheliopathy, increasing the risk of coagulation in fatal cases. Moreover, these changes may impact lymphocyte function, indicating a more extensive role for platelets in inflammatory and immune responses. This study identifies crucial biomarkers of platelet heterogeneity in serious health conditions, paving the way for innovative therapeutic approaches targeting platelet activation, which could improve patient outcomes in diseases characterized by altered platelet function.

THE THERAPEUTIC EFFICACY OF PLASMAPHERESIS FOR SEPSIS WITH MULTIPLE ORGAN FAILURE: A PROPENSITY SCORE-MATCHED ANALYSIS BASED ON THE MIMIC-IV DATABASE

ABSTRACT

Background: Despite advancements in sepsis treatment, mortality remains high. Plasmapheresis (PE) targeting multiple pathways simultaneously seems to be a potential treatment option, but evidence is insufficient. We aimed to investigate the efficacy of PE for sepsis with multiple organ failure (MOF). Method: Septic patients with MOF were identified from the Medical Information Mart for Intensive Care IV database. Patients who received PE were matched with those receiving conventional therapy via propensity score matching. Regression analyses evaluated the association between PE and outcomes. The Kaplan-Meier (KM) method was used to analyze the survival probability. The generalized additive mixed model investigated early indexes changes' association with treatment modalities and 28-day mortality. Results: Nine hundred six septic patients with MOF were enrolled. After propensity score matching, PE and conventional groups consisted of 60 cases each. Plasmapheresis was associated with a reduced risk of 28-day mortality (hazard ratio [HR], 0.50; 95% confidence interval [CI], 0.27-0.94), 1-year mortality (HR, 0.44; 95% CI, 0.26-0.74), and in-hospital mortality (HR, 0.38; 95% CI, 0.20-0.71). The KM curves demonstrated significant differences in survival probability between groups. Compared with the conventional group, the sequential organ failure assessment, norepinephrine dosage, prothrombin time, actate dehydrogenase, total bilirubin, white blood cells, and immature granulocytes in the PE group significantly decreased over time, while platelets, red blood cells, and hemoglobin significantly increased over time. Conclusions: Plasmapheresis demonstrated an association with reduced risks of 28-day, in-hospital and 1-year mortality in septic patients with MOF. Moreover, plasmapheresis might exhibit the potential to improve outcomes by improving organ function, hemodynamics, and restoring several indicators, such as coagulation, anemia, and inflammation.

Platelet P2Y12 signalling pathway in the dysregulated immune response during sepsis

Sepsis is a complicated pathological condition in response to severe infection. It is characterized by a strong systemic inflammatory response, where multiple components of the immune system are involved. Currently, there is no treatment for sepsis. Blood platelets are known for their role in haemostasis, but they also participate in inflammation through cell-cell interaction and the secretion of inflammatory mediators. Interestingly, an increase in platelet activation, secretion, and aggregation with other immune cells (such as monocytes, T-lymphocytes and neutrophils) has been detected in septic patients. Therefore, antiplatelet therapy in terms of P2Y12 antagonists has been evaluated as a possible treatment for sepis. It was found that blocking P2Y12 receptors decreased platelet marker expression and limited attachment to immune cells in some studies, but not in others. This review addresses the role of platelets in sepsis and discusses whether antagonizing P2Y12 signalling pathways can alter the disease outcome. Challenges in studying P2Y12 antagonists in sepsis also are discussed. LINKED ARTICLES: This article is part of a themed issue on Platelet purinergic receptor and non-thrombotic disease. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v181.4/issuetoc.

Association between preoperative systemic immune inflammation index and postoperative sepsis in patients with intestinal obstruction: A retrospective observational cohort study

BACKGROUND

Sepsis is a severe complication that results in increased morbidity and mortality after intestinal obstruction surgery. This study examined the role of preoperative systemic immune inflammation index (SII) for postoperative sepsis in intestinal obstruction patients.

METHODS

Data on patients who underwent intestinal obstruction surgery were collected. SII was determined and separated into two groups (≤1792.19 and >1792.19) according to the optimal cut-off value of SII for postoperative sepsis. The odds ratio (OR) is calculated for the correlation between SII and postoperative sepsis. Additional analyses were used to estimate the robustness of SII.

RESULTS

A total of 371 intestinal obstruction patients undergoing surgery were included in the final cohort, and 60 (16.17%) patients developed postoperative sepsis. Patients with an SII ＞1792.19 had a significantly higher risk for developing postoperative sepsis after multivariable adjustment [adjusted odds ratio = 2.12, 95% confidence interval: [1.02-4.40]]. The analysis of interaction showed no correlation between the preoperative SII and postoperative sepsis regarding age, hypertension, American Society of Anesthesiologists classification, blood loss, albumin, hemoglobin, creatinine, and leukocyte (all interactions p > .05). In subgroup analysis, all statistically significant subgroups showed that SII was a risk factor for postoperative sepsis (all p < .05). The analyses of subgroups and interactions revealed that the interaction effect of a preoperative SII ＞1792.19 and postoperative sepsis remained significant. A sensitivity analysis confirmed the robustness of the results.

CONCLUSIONS

A preoperative SII ＞ 1792.19 was a risk factor for postoperative sepsis in patients undergoing intestinal obstruction surgery.

The role of platelets in sepsis: A review

Sepsis, a life-threatening condition characterized by organ dysfunction, results from a complex series of pathophysiological mechanisms including immune dysfunction, an uncontrolled inflammatory response, and coagulation abnormalities. It is a major contributor to global mortality and severe disease development. Platelets, abundant in the circulatory system, are sensitive to changes in the body's internal environment and are among the first cells to respond to dysregulated pro-inflammatory and pro-coagulant reactions at the onset of sepsis. In the initial stages of sepsis, the coagulation cascade, inflammatory response, and endothelial tissue damage perpetually trigger platelet activation. These activated platelets then engage in complex inflammatory and immune reactions, potentially leading to organ dysfunction. Therefore, further research is essential to fully understand the role of platelets in sepsis pathology and to develop effective therapeutic strategies targeting the associated pathogenic pathways. This review delves into the involvement of platelets in sepsis and briefly outlines the clinical applications of associated biomarkers.

PAMPs and DAMPs in Sepsis: A Review of Their Molecular Features and Potential Clinical Implications

Sepsis is a serious organ dysfunction caused by a dysregulated immune host reaction to a pathogen. The innate immunity is programmed to react immediately to conserved molecules, released by the pathogens (PAMPs), and the host (DAMPs). We aimed to review the molecular mechanisms of the early phases of sepsis, focusing on PAMPs, DAMPs, and their related pathways, to identify potential biomarkers. We included studies published in English and searched on PubMed® and Cochrane®. After a detailed discussion on the actual knowledge of PAMPs/DAMPs, we analyzed their role in the different organs affected by sepsis, trying to elucidate the molecular basis of some of the most-used prognostic scores for sepsis. Furthermore, we described a chronological trend for the release of PAMPs/DAMPs that may be useful to identify different subsets of septic patients, who may benefit from targeted therapies. These findings are preliminary since these pathways seem to be strongly influenced by the peculiar characteristics of different pathogens and host features. Due to these reasons, while initial findings are promising, additional studies are necessary to clarify the potential involvement of these molecular patterns in the natural evolution of sepsis and to facilitate their transition into the clinical setting.

Adverse events and efficacy of second-round CAR-T cell therapy in relapsed pediatric B-ALL

OBJECTIVE

Chimeric antigen receptor (CAR) T-cell therapy has transformed the treatment approach for pediatric patients suffering from relapsed/refractory B-cell acute lymphoblastic leukemia (B-ALL). However, there was a paucity of data on the challenges associated with second-round CAR-T therapy in this population.

METHODS

Medical records of nine pediatric patients who received second-round CAR-T therapy in a single center from June 2019 to May 2023 were analyzed. Throughout the course of the clinical trial, we evaluated adverse events including CRS, CRES, infections, hematologic toxicity, and organ injury, as well as CAR-T responses.

RESULTS

Except for one patient who chose CART therapy due to testicular relapse, the remaining patients had indications for CAR-T therapy due to relapse with bone marrow alone or combined with other site. There were no difference between the transfusion dose of CART1 and CART2. No differences of incidence and grade of CRS was found between the first-round CAR-T therapy (CART1) and second-round CAR-T therapy (CART2). Additionally, we found that the incidence of CRES was higher for CART1(3/9,33.3%) than CART2(1/9,11.1%). Our findings revealed that there were no differences of IL-2, IL-4, IL-6, IL-10, IFN-γ, and TNF-α between CART1 and CART2, but the peak level of IL-17A was significantly higher in patients receiving CART1 compared to those receiving CART2 (p = .011). Early and late infection rates after CART1 were higher than CART2. Based on the dynamic changes of ANC, hemoglobin and platelet, ANC, and platelet were reduced obviously post CART. It seems that the incidences of severe thrombocytopenia and severe anemia were higher in the CART1 group compared to CART2. The MRD-negative CR rates for CART1 and CART2 are 100% and 44.4%, respectively (p = .029). All patients experienced events (relapse, chemotherapy, transplantation, or death) after receiving CART2, including one died, three discharged automatically, and the remaining five patients survived.

CONCLUSION

Although the remission rate of CART2 is not as high as the CART1 due to the severity of the disease, its safety regarding CRS, CRES, infections, and organ injury is still excellent. Therefore, CART2 remains a viable option for treating pediatric relapsed B-ALL.

Predictors of unfavourable outcome in adults with suspected central nervous system infections: a prospective cohort study

Suspected central nervous system (CNS) infections may pose a diagnostic challenge, and often concern severely ill patients. We aim to identify predictors of unfavourable outcome to prioritize diagnostics and treatment improvements. Unfavourable outcome was assessed on the Glasgow Outcome Scale at hospital discharge, defined by a score of 1 to 4. Of the 1152 episodes with suspected CNS infection, from two Dutch prospective cohorts, the median age was 54 (IQR 37-67), and 563 episodes (49%) occurred in women. The final diagnoses were categorized as CNS infection (N = 358 episodes, 31%), CNS inflammatory disease (N = 113, 10%), non-infectious non-inflammatory neurological disorder (N = 388, 34%), non-neurological infection (N = 252, 22%), and other systemic disorder (N = 41, 4%). Unfavourable outcome occurred in 412 of 1152 (36%), and 99 died (9%). Predictors for unfavourable outcomes included advanced age, absence of headache, tachycardia, altered mental state, focal cerebral deficits, cranial nerve palsies, low thrombocytes, high CSF protein, and the final diagnosis of CNS inflammatory disease (odds ratio 4.5 [95% confidence interval 1.5-12.6]). Episodes suspected of having a CNS infection face high risk of experiencing unfavourable outcome, stressing the urgent need for rapid and accurate diagnostics. Amongst the suspected CNS infection group, those diagnosed with CNS inflammatory disease have the highest risk.

S100A8/A9: An emerging player in sepsis and sepsis-induced organ injury

Sepsis, the foremost contributor to mortality in intensive care unit patients, arises from an uncontrolled systemic response to invading infections, resulting in extensive harm across multiple organs and systems. Recently, S100A8/A9 has emerged as a promising biomarker for sepsis and sepsis-induced organ injury, and targeting S100A8/A9 appeared to ameliorate inflammation-induced tissue damage and improve adverse outcomes. S100A8/A9, a calcium-binding heterodimer mainly found in neutrophils and monocytes, serves as a causative molecule with pro-inflammatory and immunosuppressive properties, which are vital in the pathogenesis of sepsis. Therefore, improving our comprehension of how S100A8/A9 acts as a pathological player in the development of sepsis is imperative for advancing research on sepsis. Our review is the first-to the best of our knowledge-to discuss the biology of S100A8/A9 and its release mechanisms, summarize recent advances concerning the vital roles of S100A8/A9 in sepsis and the consequential organ damage, and underscore its potential as a promising diagnostic biomarker and therapeutic target for sepsis.

Immature platelets in COVID-19

Platelets play a critical role in immune response. Coronavirus disease 2019 (COVID-19) patients with a severe course often show pathological coagulation parameters including thrombocytopenia, and at the same time the proportion of immature platelets increases. In this study, the platelet count and the immature platelet fraction (IPF) of hospitalized patients with different oxygenation requirements was investigated daily over a course of 40 days. In addition, the platelet function of COVID-19 patients was analyzed. It was found that the number of platelets in patients with the most severe course (intubation and extracorporeal membrane oxygenation (ECMO)) was significantly lower (111.5 ∙ 10⁶ /mL) than in the other groups (mild (no intubation, no ECMO): 203.5 ∙ 10⁶ /mL, p < .0001, moderate (intubation, no ECMO): 208.0 ∙ 10⁶ /mL, p < .0001). IPF tended to be elevated (10.9%). Platelet function was reduced. Differentiation by outcome revealed that the deceased patients had a highly significant lower platelet count and higher IPF (97.3 ∙ 10⁶ /mL, p < .0001, 12.2%, p = .0003).

Diagnostic and prognostic role of platelets in patients with sepsis and septic shock

Studies investigating the prognostic role of platelets commonly include critically ill patients, whereas data regarding the prognostic impact of platelet count in patients admitted with sepsis and septic shock is limited. Therefore, the study investigates the prognostic role of platelet count in patients with sepsis and septic shock. Consecutive patients with sepsis and septic shock from 2019 to 2021 were included monocentrically. Blood samples were retrieved from the day of disease onset (day 1), days 2, 3, 5, 7 and 10. Firstly, the diagnostic value of platelet count was tested for septic shock compared to sepsis. Secondly, the prognostic value of platelet count was tested for 30-day all-cause mortality. Statistical analyses included univariable t-test, Spearman's correlation, C-statistics, Kaplan-Meier analyses, as well as multivariable mixed analysis of variance (ANOVA), Cox proportional regression analyses and propensity score matching. A total of 358 patients with sepsis and septic shock were included with a median platelet count of 176 × 10⁶/ml. The presence of thrombocytopenia (i.e. <150 × 10⁶/ml) was associated with increased risk of 30-day mortality (HR = 1.409; 95% CI 1.057-1.878; p = .019), which was still demonstrated after propensity score matching. During the course of sepsis, a nadir was observed on sepsis day 5 with a decrease in the mean platelet count by 21.5%. Especially serum lactate, mean arterial pressure and the presence of malignancies were found to predict platelet decline during the course of sepsis/septic shock. The presence of platelet decline >25% was associated with an increased risk of 30-day all-cause mortality (HR = 1.484; 95% CI 1.045-2.109; p = .028). Following platelet decline, recovery was observed from day 5 to day 10 (mean increase 7.5%). However, platelet recovery was not found to be associated with 30-day all-cause mortality (HR = 1.072; 95% CI 0.567-2.026; p = .832). In conclusion, both thrombocytopenia and platelet decline during the course of sepsis were associated with an increased risk of 30-day all-mortality in patients admitted with sepsis or septic shock.

Clinical Value of Laboratory Biomarkers for the Diagnosis and Early Identification of Culture-Positive Sepsis in Neonates

Background

Neonatal sepsis (NS) is an important cause of mortality and morbidity in newborn infants. However, early diagnosis of proven sepsis (culture-positive sepsis) is difficult. We aimed to define the best combination of biomarkers to diagnose the onset of neonatal sepsis, distinguish culture-positive neonatal sepsis and predict the time of confirmation of neonatal sepsis.

Methods

This retrospective cohort study was conducted from January 2016 to December 2020. Clinical characteristics and laboratory results were collected from the electronic medical records. Hematology profiles and biochemical indices were obtained upon hospital admission. Multivariate logistic regression analysis was used to evaluate the risk factors and construct a nomogram. The performance of the nomogram was evaluated by receiver operating characteristic (ROC) curve and decision curve analysis (DCA). Multivariable linear regression was used to identify the association between admission-to-diagnosis interval (ADI) and correlated variables.

Results

Overall, 148 infants with neonatal sepsis (67 culture positive sepsis and 81 culture negative sepsis) and 150 controls were included. C-reactive protein (CRP) (p<0.001), platelets (PLT) (p=0.011), urea nitrogen (BUN) (p=0.001) and conjugated bilirubin (BC) (p=0.007) were independent risk factors for neonatal sepsis. The diagnostic nomogram based on CRP, PLT, BUN and BC showed excellent diagnostic accuracy for neonatal sepsis (AUC=0.928). The nomogram based on red blood cell distribution width (RDW) and mean platelet volume (MPV) was efficient in distinguishing proven neonatal sepsis from clinical sepsis, with an AUC of 0.700 in the training group and 0.689 in the validation group. Decision curve analysis (DCA) showed that the nomogram had good clinical utility. Multivariable analysis revealed gestational age, CRP, and MPV were significantly associated with admission-to-diagnosis interval in culture-positive sepsis (p < 0.001).

Conclusion

Different combinations biomarkers were performant to diagnose the onset of neonatal sepsis, distinguish culture-positive neonatal sepsis, predict the time of confirmation, and aid in individual therapy.

Dysregulated neutrophil extracellular traps formation in sepsis

The migration and antimicrobial functions of neutrophils seem to be impaired during sepsis and contribute to the dysregulation of immune responses and disease pathogenesis. However, the role of neutrophil extracellular traps (NETs) remains to be clarified. The study aimed to analyse sequential phenotypic and functional changes of neutrophils during the time following the diagnosis of sepsis. We prospectively enrolled 49 septic and 18 non-septic patients from the intensive care unit (ICU) and emergency room (ER) and 20 healthy volunteers (HV). Baseline blood samples from septic and non-septic patients were collected within 12 h of admission to the hospital. Additional septic samples were drawn at 24, 48 and 72 h after baseline. Neutrophil phenotype and degranulation capacity were assessed by flow cytometry and NET formation was quantified by fluorescence. Neutrophils from septic patients exhibited increased CD66b, CD11b and CD177 expression but displayed reduced NET formation at baseline compared with non-septic patients and HV controls. Neutrophils expressing CD177 interacted less with platelets, were related to reduced NETosis and tended to indicate a worse sepsis outcome. In vitro experiments revealed that neutrophil function is compromised by the origin of sepsis, including the pathogen type and the affected organ. Assessing a decision tree model, our study showed that CD11b expression and NETosis values are useful variables to discriminate septic from non-septic patients. We conclude that sepsis induces changes in neutrophil phenotype and function that may compromise the effective capacity of the host to eliminate pathogens.

Prognostic value of blood inflammatory parameters for predicting mortality in neonates with sepsis

BACKGROUND

Neonatal sepsis is a major cause of morbidity and mortality in neonates. The diagnosis of neonatal sepsis has been widely explored using blood inflammatory parameters. However, few researches have focused on the predictive significance of blood inflammation parameters for predicting mortality. This study aimed to evaluate the prognostic value of blood inflammatory parameters, including white blood cell (WBC), neutrophil, lymphocyte, monocyte, platelet and C-reactive protein (CRP) for predicting mortality in neonates with sepsis.

METHODS

Neonates with culture-proven sepsis were enrolled in this study. The clinical characteristics and levels of white blood cell, neutrophil, lymphocyte, monocyte, platelet and CRP were recorded. The receiver-operating characteristic (ROC) curve was applied to calculate the area under the curve (AUC) and determine the optimal cutoff values. Multivariable Cox regression model was used to evaluate the independent prognostic significance of variables. Kaplan-Meier curve was used to assess survival.

RESULTS

A total of 188 neonates with culture-proven sepsis were included for analysis. The 7-day mortality rate was 11.2 % (21/188) and the 28-day mortality rate was 13.8 % (26/188). The levels of white blood cell, neutrophil, monocyte and platelet in non-survivors were lower than those in survivors (P < 0.05). Platelet yielded higher AUC values than other parameters for predicting mortality with the best cutoff value of 132 × 109/L, followed by WBC with the optimal cutoff value of 6.15 × 109/L. Multivariable Cox regression analysis showed platelet and WBC were independent prognostic factors for predicting mortality. Low platelet group showed lower survival according to Kaplan-Meier method.

CONCLUSIONS

In conclusion, the levels of platelet and WBC on the day of sepsis onset are valuable indicators for predicting mortality in neonates with sepsis.

Risk Estimation of Severe COVID-19 Based on Initial Biomarker Assessment Across Racial and Ethnic Groups

CONTEXT.—

Disease courses in COVID-19 patients vary widely. Prediction of disease severity on initial diagnosis would aid appropriate therapy, but few studies include data from initial diagnosis.

OBJECTIVE.—

To develop predictive models of COVID-19 severity based on demographic, clinical, and laboratory data collected at initial patient contact after diagnosis of COVID-19.

DESIGN.—

We studied demographic data and clinical laboratory biomarkers at time of diagnosis, using backward logistic regression modeling to determine severe and mild outcomes. We used deidentified data from 14 147 patients who were diagnosed with COVID-19 by polymerase chain reaction SARS-CoV-2 testing at Montefiore Health System, from March 2020 to September 2021. We generated models predicting severe disease (death or more than 90 hospital days) versus mild disease (alive and fewer than 2 hospital days), starting with 58 variables, by backward stepwise logistic regression.

RESULTS.—

Of the 14 147 patients, including Whites, Blacks, and Hispanics, 2546 (18%) patients had severe outcomes and 3395 (24%) had mild outcomes. The final number of patients per model varied from 445 to 755 because not all patients had all available variables. Four models (inclusive, receiver operating characteristic, specific, and sensitive) were identified as proficient in predicting patient outcomes. The parameters that remained in all models were age, albumin, diastolic blood pressure, ferritin, lactic dehydrogenase, socioeconomic status, procalcitonin, B-type natriuretic peptide, and platelet count.

CONCLUSIONS.—

These findings suggest that the biomarkers found within the specific and sensitive models would be most useful to health care providers on their initial severity evaluation of COVID-19.

Initial indicators for the prognosis of Acinetobacter Baumannii bacteremia in children

BACKGROUND

Risk factors related to mortality due to Acinetobacter baumannii (AB) bacteremia have been unveiled previously, but early clinical manifestations of AB bacteremia based on prognosis remain uncovered.

METHODS

The demographic characteristics, clinical features, antibiotic susceptibility, and outcomes of 37 hospitalized children with laboratory-confirmed AB bacteremia from Suzhou, China, were collected and analyzed retrospectively.

RESULTS

Of the 37 children with AB bacteremia included in this study, 23 were males and 14 were females, with a median age of 4.83 (0.60 to 10.15) years. Among the children, 18 died (48.65%, 18/37) and 19 survived (51.35%, 19/37). The dead group had a significantly higher incidence of respiratory failure (p = 0.008), shock (P = 0.000), MODS (p = 0.000), neutropenia (< 1.5 × 109/L) (p = 0.000) and serious neutropenia (< 0.5 × 109/L) (p = 0.000) than those in the survival group. The death group had significantly more invasive procedures (2 or more) than that in the survival group at 2 weeks before onset (p = 0.005). The proportion of MDR-AB in the death group was significantly higher than that in the survival group (p = 0.000), while the PICS score was significantly lower in the survival group than that in the death group (p = 0.000). There was no significant difference in effective antibiotic use within 24 h between these two groups (p = 0.295). Among the 37 children with bloodstream infection of AB, 56.76% (21/37) of the underlying diseases were hematological diseases and oncology. Among them, 17 (81.00%) were died in the hospital. The proportion of white blood cells (p = 0.000), neutrophils (p = 0.042), eosinophils (p = 0.029), the ANC (p = 0.000) and lymphocyte (p = 0.000), the NLR(p = 0.011), hemoglobin (p = 0.001), platelets (p = 0.000), prealbumin (P = 0.000), LDH (p = 0.017), blood gas pH (p = 0.000), and serum potassium (p = 0.002) in the death group were significantly lower than those in the survival group. However, CRP (p = 0.000) and blood glucose(p = 0.036) were significantly higher in the death group than those in the survival group. By further multivariate analysis, CRP [OR (95% CI): 1.022(1.003, 1.041), p = 0.021] and neutropenia [OR (95% CI): 21.634 (2.05, 228.313, p = 0.011] within 24 h of infection were independent risk factors for death in children with AB bacteremia. When CRP was higher than 59.02 mg/L, the sensitivity of predicting mortality was 88.9%, and the specificity was 78.9%. And the sensitivity and specificity of neutropenia for predicting mortality were 83.3% and 84.2%.

CONCLUSIONS

AB bacteremia has a high mortality in children, especially in patients with hematological diseases and oncology. Many early indicators were associated with poor prognosis, while elevated CRP and neutropenia were the independent predictors for the 30-day mortality of children with laboratory-confirmed AB bacteremia.

Current knowledge of thrombocytopenia in sepsis and COVID-19

Thrombocytopenia, characterized by a decrease in platelet count, is commonly observed in sepsis and COVID-19. In sepsis, thrombocytopenia can result from various mechanisms, including impaired platelet production in the bone marrow, accelerated platelet destruction due to increased inflammation, sequestration of platelets in the spleen, immune-mediated platelet destruction, or dysregulated host responses. Similarly, thrombocytopenia has been reported in COVID-19 patients, but the immune-related mechanisms underlying this association remain unclear. Notably, interventions targeting thrombocytopenia have shown potential for improving outcomes in both sepsis and COVID-19 patients. Understanding these mechanisms is crucial for developing effective treatments.

Platelet count predicts mortality in patients with sepsis: A retrospective observational study

Platelet count is a key component of sepsis severity score. However, the predictive value of the platelet count at admission for mortality in sepsis remains unclear. We designed a retrospective observational study of patients with sepsis admitted to our hospital from January 2017 to September 2021 to explore the predictive value of platelet count at admission for mortality. A total of 290 patients with sepsis were included in this study. Multivariate logistic regression analysis was used to evaluate the risk factors for mortality and construct a predictive model with statistically significant factors. Compared with survivors, nonsurvivors tended to be much older and had significantly higher acute physiology and chronic health evaluation II and sequential organ failure assessment scores (P < .001). The platelet count was significantly lower in the nonsurvivor group than in the survivor group (P < .001). Multivariate logistic regression analysis indicated that age (P = .003), platelet count (P < .001) and lactate level (P = .018) were independent risk factors for mortality in patients with sepsis. Finally, the area under the receiver operating characteristic curve of platelet count predicting mortality in sepsis was 0.763 (95% confidence interval, 0.709-0.817, P < .001), with a sensitivity of 55.6% and a specificity of 91.8%. In our study, platelet count at admission as a single biomarker showed good predictability for mortality in patients with sepsis.

Performance of Platelet Mass Index as a Marker of Severity for Sepsis and Septic Shock in Children

Platelet mass index (PMI) as a prognostic indicator in pediatric sepsis has not been previously reported. In this retrospective observational study, we evaluated PMI's performance as a prognostic indicator in children aged younger than 18 years with sepsis and septic shock in relationship with survival. Over 5 years, we collected data from 122 children admitted to our pediatric intensive care unit (PICU). PMI accuracy was assessed with sensitivity and specificity and its discrimination was assessed using the area under the receiver operating characteristic curve (AUC). Median PMI values on days 1 and 3 of PICU admission were lower among nonsurvivors. On day 1 of PICU admission, a cutoff PMI value of 1,450 fL/nL resulted in a sensitivity of 72% and a specificity of 69%, and the AUC was 0.70 (95% confidence interval [CI]: 0.55-0.86). Similarly, on day 3, a cutoff of 900 fL/nL resulted in a sensitivity of 71% and a specificity of 70%, and the AUC was 0.76 (95% CI: 0.59-0.92). Our exploratory study suggests that low PMI in children with septic shock is associated with increased mortality. Considering the PMI's fair performance, further studies should be performed to assess its clinical value.

Effect of COVID-19 Pandemic on Patients Who Have Undergone Liver Transplantation: Retrospective Cohort Study

BACKGROUND

In liver transplant (LT) recipients, immunosuppressive therapy may potentially increase the risk of severe COVID-19 and may increase the mortality in patients. However, studies have shown conflicting results, with various studies reporting poor outcomes while the others show no difference between the LT recipients and healthy population. The aim of this study is to determine the impact of the COVID-19 pandemic on survival of LT recipients.

METHODS

This is a retrospective cohort study analyzing the data from 387 LT recipients diagnosed with COVID-19. LT recipients were divided into two groups: survival (n = 359) and non-survival (n = 28) groups. A logistic regression model was used to determine the independent risk factors for mortality. Machine learning models were used to analyze the contribution of independent variables to the mortality in LT recipients.

RESULTS

The COVID-19-related mortality rate in LT recipients was 7.2%. Multivariate analysis showed that everolimus use (p = 0.012; OR = 6.2), need for intubation (p = 0.001; OR = 38.4) and discontinuation of immunosuppressive therapy (p = 0.047; OR = 7.3) were independent risk factors for mortality. Furthermore, COVID-19 vaccination reduced the risk of mortality by 100 fold and was the single independent factor determining the survival of the LT recipients.

CONCLUSION

The effect of COVID-19 infection on LT recipients is slightly different from the effect of the disease on the general population. The COVID-19-related mortality is lower than the general population and vaccination for COVID-19 significantly reduces the risk of mortality.

Bone Marrow Changes in Septic Shock: A Comprehensive Review

Septic shock is a life-threatening condition characterized by systemic inflammation resulting from a severe infection. Although the primary focus of sepsis research has traditionally been on the dysfunctional immune response, recent studies have highlighted the important role of bone marrow in the pathophysiology of septic shock. The bone marrow, traditionally regarded as the hematopoietic organ responsible for blood cell production, undergoes significant changes during sepsis, contributing to the overall immune dysregulation observed in this condition. This comprehensive review aims to provide a detailed overview of the bone marrow changes associated with septic shock. It explores the alterations in the bone marrow microenvironment, hematopoietic progenitor cells, and the subsequent effects on leukocyte production and function. Key cellular and molecular mechanisms involved in bone marrow dysfunction during septic shock are discussed, including the dysregulation of cytokines, chemokines, growth factors, and signaling pathways. Furthermore, this review highlights the clinical implications of bone marrow changes in septic shock. It emphasizes the impact of altered hematopoiesis on immune cell populations, such as neutrophils, monocytes, and lymphocytes, and their role in the progression and outcome of sepsis. The potential prognostic value of bone marrow parameters and the therapeutic implications of targeting bone marrow dysfunction are also addressed. The review summarizes relevant preclinical and clinical studies to comprehensively understand the current knowledge of bone marrow changes in septic shock. The limitations and challenges of studying bone marrow in the context of sepsis are acknowledged, and future directions for research are proposed.

Myristica fragrans Extract Inhibits Platelet Desialylation and Activation to Ameliorate Sepsis-Associated Thrombocytopenia in a Murine CLP-Induced Sepsis Model

Sepsis, characterized by an uncontrolled host inflammatory response to infections, remains a leading cause of death in critically ill patients worldwide. Sepsis-associated thrombocytopenia (SAT), a common disease in patients with sepsis, is an indicator of disease severity. Therefore, alleviating SAT is an important aspect of sepsis treatment; however, platelet transfusion is the only available treatment strategy for SAT. The pathogenesis of SAT involves increased platelet desialylation and activation. In this study, we investigated the effects of Myristica fragrans ethanol extract (MF) on sepsis and SAT. Desialylation and activation of platelets treated with sialidase and adenosine diphosphate (platelet agonist) were assessed using flow cytometry. The extract inhibited platelet desialylation and activation via inhibiting bacterial sialidase activity in washed platelets. Moreover, MF improved survival and reduced organ damage and inflammation in a mouse model of cecal ligation and puncture (CLP)-induced sepsis. It also prevented platelet desialylation and activation via inhibiting circulating sialidase activity, while maintaining platelet count. Inhibition of platelet desialylation reduces hepatic Ashwell-Morell receptor-mediated platelet clearance, thereby reducing hepatic JAK2/STAT3 phosphorylation and thrombopoietin mRNA expression. This study lays a foundation for the development of plant-derived therapeutics for sepsis and SAT and provides insights into sialidase-inhibition-based sepsis treatment strategies.

Platelet-monocyte aggregates: molecular mediators of thromboinflammation

Platelets, key facilitators of primary hemostasis and thrombosis, have emerged as crucial cellular mediators of innate immunity and inflammation. Exemplified by their ability to alter the phenotype and function of monocytes, activated platelets bind to circulating monocytes to form monocyte-platelet aggregates (MPA). The platelet-monocyte axis has emerged as a key mechanism connecting thrombosis and inflammation. MPA are elevated across the spectrum of inflammatory and autoimmune disorders, including cardiovascular disease, systemic lupus erythematosus (SLE), and COVID-19, and are positively associated with disease severity. These clinical disorders are all characterized by an increased risk of thromboembolic complications. Intriguingly, monocytes in contact with platelets become proinflammatory and procoagulant, highlighting that this interaction is a central element of thromboinflammation.

Applications of Artificial Intelligence in Thrombocytopenia

Thrombocytopenia is a medical condition where blood platelet count drops very low. This drop in platelet count can be attributed to many causes including medication, sepsis, viral infections, and autoimmunity. Clinically, the presence of thrombocytopenia might be very dangerous and is associated with poor outcomes of patients due to excessive bleeding if not addressed quickly enough. Hence, early detection and evaluation of thrombocytopenia is essential for rapid and appropriate intervention for these patients. Since artificial intelligence is able to combine and evaluate many linear and nonlinear variables simultaneously, it has shown great potential in its application in the early diagnosis, assessing the prognosis and predicting the distribution of patients with thrombocytopenia. In this review, we conducted a search across four databases and identified a total of 13 original articles that looked at the use of many machine learning algorithms in the diagnosis, prognosis, and distribution of various types of thrombocytopenia. We summarized the methods and findings of each article in this review. The included studies showed that artificial intelligence can potentially enhance the clinical approaches used in the diagnosis, prognosis, and treatment of thrombocytopenia.

NINJ1 Regulates Platelet Activation and PANoptosis in Septic Disseminated Intravascular Coagulation

Disseminated intravascular coagulation (DIC), which is closely related to platelet activation, is a key factor leading to high mortality in sepsis. The release of contents from plasma membrane rupture after platelet death further aggravates thrombosis. Nerve injury-induced protein 1 (NINJ1) is a cell membrane protein that mediates membrane disruption, a typical marker of cell death, through oligomerization. Nevertheless, whether NINJ1 is expressed in platelets and regulates the platelet function remains unclear. The aim of this study was to evaluate the expression of NINJ1 in human and murine platelets and elucidate the role of NINJ1 in platelets and septic DIC. In this study, NINJ1 blocking peptide (NINJ1_26-37) was used to verify the effect of NINJ1 on platelets in vitro and in vivo. Platelet αIIbβ3 and P-selectin were detected by flow cytometry. Platelet aggregation was measured by turbidimetry. Platelet adhesion, spreading and NINJ1 oligomerization were examined by immunofluorescence. Cecal perforation-induced sepsis and FeCl₃-induced thrombosis models were used to evaluate the role of NINJ1 in platelet, thrombus and DIC in vivo. We found that inhibition of NINJ1 alleviates platelet activation in vitro. The oligomerization of NINJ1 is verified in membrane-broken platelets, which is regulated by the PANoptosis pathway. In vivo studies demonstrate that inhibition of NINJ1 effectively reduces platelet activation and membrane disruption, thus suppressing platelet-cascade reaction and leading to anti-thrombosis and anti-DIC in sepsis. These data demonstrate that NINJ1 is critical in platelet activation and plasma membrane disruption, and inhibition of NINJ1 effectively reduces platelet-dependent thrombosis and DIC in sepsis. This is the first study to reveal the key role of NINJ1 in platelet and its related disorders.

Combining Serum Procalcitonin Level, Thromboelastography, and Platelet Count to Predict Short-term Development of Septic Shock in Intensive Care Unit

OBJECTIVE

Despite the recent advances in diagnosis and treatment, sepsis continues to lead to high morbidity and mortality. Early diagnosis and prompt treatment are essential to save lives. However, most biomarkers can only help to diagnose sepsis, but cannot predict the development of septic shock in high-risk patients. The present study determined whether the combined measurement of procalcitonin (PCT), thromboelastography (TEG) and platelet (PLT) count can predict the development of septic shock.

METHODS

A retrospective study was conducted on 175 septic patients who were admitted to the intensive care unit between January 2017 and February 2021. These patients were divided into two groups: 73 patients who developed septic shock were assigned to the septic shock group, while the remaining 102 patients were assigned to the sepsis group. Then, the demographic, clinical and laboratory data were recorded, and the predictive values of PCT, TEG and PLT count for the development of septic shock were analyzed.

RESULTS

Compared to the sepsis group, the septic shock group had statistically lower PLT count and TEG measurements in the R value, K value, α angle, maximum amplitude, and coagulation index, but had longer prothrombin time (DT), longer activated partial thromboplastin time (APTT), and higher PCT levels. Furthermore, the Sequential Organ Failure Assessment (SOFA) score was higher in the septic shock group. The multivariate logistic regression analysis revealed that PCT, TEG and PLT count were associated with the development of septic shock. The area under the curve analysis revealed that the combined measurement of PCT, TEG and PLT count can be used to predict the development of septic shock with higher accuracy, when compared to individual measurements.

CONCLUSION

The combined measurement of PCT, TEG and PLT count is a novel approach to predict the development of septic shock in high-risk patients.

Pathogenesis of Anemia in Canine Babesiosis: Possible Contribution of Pro-Inflammatory Cytokines and Chemokines-A Review

Canine babesiosis is a tick-borne protozoan disease caused by intraerythrocytic parasites of the genus Babesia. The infection may lead to anemia in infected dogs. However, anemia is not directly caused by the pathogen. The parasite's developmental stages only have a marginal role in contributing to a decreased red blood cell (RBC) count. The main cause of anemia in affected dogs is the immune response to the infection. This response includes antibody production, erythrophagocytosis, oxidative damage of RBCs, complement activation, and antibody-dependent cellular cytotoxicity. Moreover, both infected and uninfected erythrocytes are retained in the spleen and sequestered in micro-vessels. All these actions are driven by pro-inflammatory cytokines and chemokines, especially IFN-γ, TNF-α, IL-6, and IL-8. Additionally, imbalance between the actions of pro- and anti-inflammatory cytokines plays a role in patho-mechanisms leading to anemia in canine babesiosis. This article is a review of the studies on the pathogenesis of anemia in canine babesiosis and related diseases, such as bovine or murine babesiosis and human or murine malaria, and the role of pro-inflammatory cytokines and chemokines in the mechanisms leading to anemia in infected dogs.

Liang-Ge Decoction Ameliorates Coagulation Dysfunction in Cecal Ligation and Puncture-Induced Sepsis Model Rats through Inhibiting PAD4-Dependent Neutrophil Extracellular Trap Formation

Liang-Ge (LG) decoction could ameliorate coagulation dysfunction in septic model rats. However, the mechanism of LG in treating sepsis still needs to be clarified. Our current study established a septic rat model to evaluate the effect of LG on coagulation dysfunction in septic rats first. Second, we investigated the effect of LG on NET formation in septic rats. Finally, NETs and PAD4 inhibitors were further used to clarify if LG could improve the mechanism of sepsis coagulation dysfunction by inhibiting NET formation. Our findings indicated that treatment with LG improved the survival rate, reduced inflammatory factor levels, enhanced hepatic and renal function, and reduced pathological changes in rats with sepsis. LG could also alleviate coagulation dysfunction in septic model rats. Besides, LG treatment reduced NETs formation and decreased PAD4 expression in neutrophiles. In addition, LG treatment showed a similar result in comparison to the treatment with either NET inhibitors or PAD4 inhibitors alone. In conclusion, this study confirmed that LG has therapeutic effects on septic rats. Furthermore, the improvement of coagulation dysfunction in septic rats by LG was achieved through inhibiting PAD4-mediated NET formation.

Sex differences in clinical presentation and mortality in emergency department patients with sepsis

BACKGROUND

There is growing awareness that sex differences are associated with different patient outcomes in a variety of diseases. Studies investigating the effect of patient sex on sepsis-related mortality remain inconclusive and mainly focus on patients with severe sepsis and septic shock in the intensive care unit. We therefore investigated the association between patient sex and both clinical presentation and 30-day mortality in patients with the whole spectrum of sepsis severity presenting to the emergency department (ED) who were admitted to the hospital.

MATERIALS AND METHODS

In our multi-centre cohort study, we retrospectively investigated adult medical patients with sepsis in the ED. Multivariable analysis was used to evaluate the association between patient sex and all-cause 30-day mortality.

RESULTS

Of 2065 patients included, 47.6% were female. Female patients had significantly less comorbidities, lower Sequential Organ Failure Assessment score and abbreviated Mortality Emergency Department Sepsis score, and presented less frequently with thrombocytopenia and fever, compared to males. For both sexes, respiratory tract infections were predominant while female patients more often had urinary tract infections. Females showed lower 30-day mortality (10.1% vs. 13.6%; p = .016), and in-hospital mortality (8.0% vs. 11.1%; p = .02) compared to males. However, a multivariable logistic regression model showed that patient sex was not an independent predictor of 30-day mortality (OR 0.90; 95% CI 0.67-1.22; p = .51).

CONCLUSIONS

Females with sepsis presenting to the ED had fewer comorbidities, lower disease severity, less often thrombocytopenia and fever and were more likely to have a urinary tract infection. Females had a lower in-hospital and 30-day mortality compared to males, but sex was not an independent predictor of 30-day mortality. The lower mortality in female patients may be explained by differences in comorbidity and clinical presentation compared to male patients.KEY MESSAGESOnly limited data exist on sex differences in sepsis patients presenting to the emergency department with the whole spectrum of sepsis severity.Female sepsis patients had a lower incidence of comorbidities, less disease severity and a different source of infection, which explains the lower 30-day mortality we found in female patients compared to male patients.We found that sex was not an independent predictor of 30-day mortality; however, the study was probably underpowered to evaluate this outcome definitively.

Characterization of the impact of immune checkpoint inhibitors on platelet activation and aggregation

Immune checkpoint inhibitors (ICIs) are effective oncological drugs which block cellular check-point receptors typically targeted by tumor immune evasion strategies. Despite their benefits, clinicians have reported treatment-associated thromboembolism during ICI therapy in recent years. Though several theories on this ICI-associated pathogenesis exist, the direct effects of ICIs on platelets remains unknown. We therefore investigated the potential direct and indirect effect of PD-1, PD-L1 and CTLA-4-targeting ICIs on platelet functionality in multifaceted in vitro experiments. Interestingly, we could not observe a clear effect of ICI on platelet aggregation and primary hemostasis in whole blood and platelet concentrate-based assays. Furthermore, the presence of ICIs in toll-like receptor stimulation had no significant impact on platelet surface marker expression. In a second approach, we investigated the indirect immunological impact of ICIs on platelet activation by exposing platelets to supernatants from ICI- and Staphylococcal enterotoxin B-exposed PBMCs. Whereas ICIs affected IL-2 levels in supernatants, we could not detect clear differences in the secretion of pro-thrombogenic factors and platelet responses. The obtained data suggest that the direct influence of ICIs on platelet activation or the influence of altered T cell function on platelet activation cannot be considered a major factor in the development of thrombotic events.

Potential Biomarkers for Early Diagnosis, Evaluation, and Prognosis of Sepsis-Induced Coagulopathy

Sepsis-induced coagulopathy (SIC) is a life-threatening complication characterized by the systemic activation of coagulation in sepsis. The diagnostic criteria of SIC consist of three items, including Sequential Organ Failure Assessment (SOFA) score, platelet count, and prothrombin time (PT)-international normalized ratio (INR). SIC has a high prevalence and it can lead to a higher mortality rate and longer length of hospital and ICU stay. Thus, the early detection of SIC is extremely important. It is unfortunate that there is still no precise biomarker for early diagnosis and assessment of the prognosis of SIC. We reviewed the current literature and discovered that some potential biomarkers, such as soluble thrombomodulin (sTM), thrombin-antithrombin complex (TAT), tissue plasminogen activator-inhibitor complex (t-PAIC), α2-plasmin inhibitor-plasmin complex (PIC), C-type lectin-like receptor 2 (CLEC-2), neutrophil extracellular traps (NETs), prothrombin fragment 1.2 (F1.2), Angiopoietin-2 (Ang-2), plasminogen activator inhibitor-1 (PAI-1), and tissue inhibitor of metalloproteinase-1 (TIMP-1) may be useful for early diagnosis, evaluation, and prognosis of SIC. Early initiation of treatment without missing any therapeutic opportunities may improve SIC patients' prognosis. Further large-scale clinical studies are still needed to confirm the role of these biomarkers in the diagnosis and prognosis assessment of SIC.

Histone Citrullination Mediates a Protective Role in Endothelium and Modulates Inflammation

NETosis is a key host immune process against a pathogenic infection during innate immune activation, consisting of a neutrophil "explosion" and, consequently, NET formation, containing mainly DNA, histones, and other nuclear proteins. During sepsis, an exacerbated immune host response to an infection occurs, activating the innate immunity and NETosis events, which requires histone H3 citrullination. Our group compared the circulating histone levels with those citrullinated H3 levels in plasma samples of septic patients. In addition, we demonstrated that citrullinated histones were less cytotoxic for endothelial cells than histones without this post-translational modification. Citrullinated histones did not affect cell viability and did not activate oxidative stress. Nevertheless, citrullinated histones induced an inflammatory response, as well as regulatory endothelial mechanisms. Furthermore, septic patients showed elevated levels of circulating citrullinated histone H3, indicating that the histone citrullination is produced during the first stages of sepsis, probably due to the NETosis process.

Innate immune TLR7 signaling mediates platelet activation and platelet-leukocyte aggregate formation in murine bacterial sepsis

Thrombocytopenia is a common complication in sepsis and is associated with higher mortality. Activated platelets express CD62P, which facilitates platelet-leukocyte aggregate (PLA) formation and contributes to thrombocytopenia in sepsis. We have reported that thrombocytopenia in murine sepsis is partly attributable to TLR7 signaling, but the underlying mechanism is unclear. In the current study, we tested the hypothesis that TLR7 mediates platelet activation and PLA formation during sepsis. In vitro, whole blood from WT mice treated with loxoribine, a TLR7 agonist, exhibited a dose-dependent increase in activated platelets compared to the control (PBS with 0.05% DMSO) or loxoribine-treated TLR7^-/- whole blood. In a murine model of sepsis, there was a significant increase in platelet activation and PLA formation 24 hours after cecal ligation and puncture (CLP) as evidenced by double positive expression of CD41⁺/CD62P⁺ and CD45⁺/CD62P⁺, respectively. The sepsis-induced PLA formation was significantly attenuated in TLR7^-/- mice. Finally, in ex-vivo experiments, plasma isolated from septic mice induced WT platelet activation, but such effect was significantly attenuated in platelets deficient of TLR7. These findings demonstrate a pivotal role of TLR7 signaling in platelet activation and PLA formation during bacterial sepsis.

Forsythiaside B ameliorates coagulopathies in a rat model of sepsis through inhibition of the formation of PAD4-dependent neutrophil extracellular traps

Forsythiaside B (FTB) is one of the main components of Forsythia suspensa (Thunb.) Vahl and exerts anti-inflammatory and anti-oxidative effects. However, its mechanism of action as a treatment for sepsis remains unclear. In this study, we developed a rat model of sepsis using cecal ligation and puncture (CLP) to investigate the effects of FTB on sepsis-associated coagulopathies. Using rats with sepsis, we investigated the effects of FTB on neutrophil extracellular trap (NETs) formation and peptidylarginine deiminase 4 (PAD4) expression in neutrophils. NET (DNase1) and PAD4 (Cl-amidine) inhibitors were used to further investigate whether FTB mitigates sepsis-associated coagulopathies by inhibiting PAD4-dependent NETs production. Our results showed that treatment with FTB increased the survival rate, ameliorated the CLP-induced inflammatory response and multiple organ dysfunction, and reduced CLP-induced pathological changes. FTB also alleviated the associated coagulopathies. Additionally, we demonstrated that treatment with FTB inhibited NETs formation and downregulated PAD4 expression in peripheral neutrophils. The effects of FTB on coagulopathies were similar to those of monotherapy with NET or PAD4 inhibitors. In conclusion, our study confirmed that FTB can alleviate coagulopathies in rats with sepsis. The underlying mechanism of FTB's effect consists in inhibition of PAD4-dependent NETs formation.

Effect of platelet count and platelet transfusion on fever duration in patients with febrile neutropenia

Platelets play a role in hemostasis, thrombosis, and vascular integrity. They also play a major role in the development of inflammation and the activation of immune responses. They have phagocytic activity, stimulate the secretion of immune modulators, and activate other immune cells, which results in platelet-neutrophil aggregation, platelet-induced neutrophil degranulation, and the formation of neutrophil extracellular traps. Data on 124 febrile neutropenia attacks were retrospectively examined. Patients' age, sex, diagnosis, and relapse history were obtained. The complete blood count levels on the first and last febrile day of the febrile neutropenia attacks, duration of fever, and number, type, and timing of thrombocyte suspension transfusions were recorded. The patients were divided into three groups according to the day of fever when the platelet suspension was administered (1 day, 2-3 days, and >3 days); the duration of fever was compared between the three groups. The fever duration of those who were transfused with platelet suspension on the first day of fever was found to be significantly shorter (p = 0.03 and p < 0.001, respectively). When treating a patient with febrile neutropenia, if thrombocyte suspension transfusion is indicated, transfusing thrombocytes in the first days of fever shortens the fever duration and improves the prognosis of febrile neutropenia attack, supporting the hypothesis that not only neutrophils but also platelets may play a role in fighting against microorganisms.

Protein arginine methyltransferase 1 in the generation of immune megakaryocytes: A perspective review

Megakaryocytes (Mks) in bone marrow are heterogeneous in terms of polyploidy. They not only produce platelets but also support the self-renewal of hematopoietic stem cells and regulate immune responses. Yet, how the diverse functions are generated from the heterogeneous Mks is not clear at the molecular level. Advances in single-cell RNA seq analysis from several studies have revealed that bone marrow Mks are heterogeneous and can be clustered into 3 to 4 subpopulations: a subgroup that is adjacent to the hematopoietic stem cells, a subgroup expressing genes for platelet biogenesis, and a subgroup expressing immune-responsive genes, the so-called immune Mks that exist in both humans and mice. Immune Mks are predominantly in the low-polyploid (≤8 N nuclei) fraction and also exist in the lung. Protein arginine methyltransferase 1 (PRMT1) expression is positively correlated with the expression of genes involved in immune response pathways and is highly expressed in immune Mks. In addition, we reported that PRMT1 promotes the generation of low-polyploid Mks. From this perspective, we highlighted the data suggesting that PRMT1 is essential for the generation of immune Mks via its substrates RUNX1, RBM15, and DUSP4 that we reported previously. Thus, we suggest that protein arginine methylation may play a critical role in the generation of proinflammatory platelet progeny from immune Mks, which may affect many immune, thrombotic, and inflammatory disorders.

The Efficacy of Albumin Channa Striata Extract Administration in Stabilizing PAI-1 and Platelet Levels in Septic Patients: A Randomized Control Trial Study

BACKGROUND: Recently, sepsis has become a serious problem worldwide. There are many studies trying to find the etiologies of morbidity and mortality of sepsis. One of them is the damage of endothelial glycocalyx layer, which can lead to an increase in plasminogen activator inhibitor-1 (PAI-1) level and a decrease in platelets. This damage can be prevented by administering albumin; unfortunately, it is costly. Therefore, an alternative albumin is required. Channa striata extract albumin has been found to be relatively effective in increasing serum albumin levels. However, studies on its effectiveness are still limited. Hence, we analyzed this channa striata extract albumin in stabilizing PAI-1 and platelet levels of septic patients. AIM: This study analyzed channa striata extract albumin in stabilizing PAI-1 and platelet levels of septic patients. METHODS: We conducted a randomized control experimental study in patients with sepsis hospitalized at Dr Moewardi Hospital, Surakarta, Indonesia. The samples were taken by consecutive sampling technique. These patients were allocated into two groups, the albumin extract of channa striata, and human albumin 20% (the control) groups. We examined the PAI-1 and platelet levels on the 1st and 3rd days. We used Mann–Whitney test for statistical analysis with p < 0.05 was considered significant. RESULTS: There were 21 subjects in each group of channa striata (study) and human albumin (control). The increase of PAI-1 level in the study group (0.36 ng/ml) was lower than that of in control group (0.72 ng/ml). More subjects in study group experienced decreased PAI-1 level (n = 5) than those in control group (n = 3), the decrease more profound in control group (p = 0.004) than study group (p = 0.054). The decrease of platelet level was also greater in study group (22 × 103/mcl) than that of in control group (1 × 103.md) despite insignificant difference (p = 0.364 and p = 0.468). CONCLUSION: The administration of channa striata extract effective in stabilizing PAI-1 level in sepsis patient and also had potential benefit as human albumin in stabilizing platelet levels of septic patients.

Platelet index on admission as a predictor of bacteremia in acute cholangitis: a 7-year retrospective observational study

Bacteremia frequently occurs in patients with acute cholangitis, which could increase the risk of mortality. This single-center retrospective observational study was conducted from July 2013 to July 2020 to evaluate the predictive value of platelet index for bacteremia at admission for acute cholecystitis. A total of 285 patients with acute cholangitis were divided into bacteremia group and non-bacteremia group. The incidence of bacteremia in acute cholangitis was 48.42%. The bacteremia group had more grade III patients, higher 30d mortality rate [17(12.32%) vs 8(5.44%), p = .040] and higher incidence of thrombocytopenia [76(55.07%) vs 35(23.81%), p < .001]. Platelet counts and plateletcrit were significantly lower in the bacteremia group [84.5(60, 180) vs 162(102,225) ×10⁹/L and 0.10(0.07, 0.21)% vs 0.18(0.12, 0.25) %, both p < .001]. ROC analysis indicated a high predictive value of platelet count and plateletcrit for bacteremia in patients with acute cholangitis and the area under the ROC curve (AUC) were 0.649 and 0.655, respectively. These results support the value of platelet count and plateletcrit in early prediction of bacteremia at admission for acute cholangitis.

Stachydrine exhibits a novel antiplatelet property and ameliorates platelet-mediated thrombo-inflammation

BACKGROUND

Platelets are versatile anucleate cells involved in thrombosis as well as inflammation. Stachydrine (STA), a major bioactive compound extracted from Motherwort, has multiple pharmacological properties. Nevertheless, the significance of STA in platelet regulation and whether STA could ameliorate platelet-mediated thrombo-inflammation still remain elusive.

METHODS

Human platelets were used to assess the regulatory effects of STA on platelet activation and interactions with neutrophils in vitro. FeCl₃ injury-induced carotid/mesenteric thrombosis and collagen/epinephrine-induced pulmonary thromboembolism model were used to explore whether STA could regulate thrombosis in vivo. Furthermore, a cecal ligation and puncture-induced sepsis model was employed to investigate the role of STA in thrombo-inflammatory diseases.

RESULTS

STA markedly suppressed platelet activation represented by aggregation, secretion, αIIbβ3-mediated signaling events and calcium mobilization, etc. by inhibiting agonists-induced activation signaling and potentiating cGMP-dependent inhibitory signaling. Mice receiving STA-treated platelets were less susceptible to thrombosis in vivo. In addition, decreased platelet-neutrophil interactions including platelet-neutrophil aggregates and neutrophil extracellular traps, and alleviative sepsis-induced multiorgan damage were observed due to STA-mediated platelet inhibition.

CONCLUSION

This study suggested the potential therapeutic role of STA in thrombotic and thrombo-inflammatory disorders.

Identifying the Risk of Sepsis in Patients With Cancer Using Digital Health Care Records: Machine Learning-Based Approach

BACKGROUND

Sepsis is diagnosed in millions of people every year, resulting in a high mortality rate. Although patients with sepsis present multimorbid conditions, including cancer, sepsis predictions have mainly focused on patients with severe injuries.

OBJECTIVE

In this paper, we present a machine learning-based approach to identify the risk of sepsis in patients with cancer using electronic health records (EHRs).

METHODS

We utilized deidentified anonymized EHRs of 8580 patients with cancer from the Samsung Medical Center in Korea in a longitudinal manner between 2014 and 2019. To build a prediction model based on physical status that would differ between sepsis and nonsepsis patients, we analyzed 2462 laboratory test results and 2266 medication prescriptions using graph network and statistical analyses. The medication relationships and lab test results from each analysis were used as additional learning features to train our predictive model.

RESULTS

Patients with sepsis showed differential medication trajectories and physical status. For example, in the network-based analysis, narcotic analgesics were prescribed more often in the sepsis group, along with other drugs. Likewise, 35 types of lab tests, including albumin, globulin, and prothrombin time, showed significantly different distributions between sepsis and nonsepsis patients (P<.001). Our model outperformed the model trained using only common EHRs, showing an improved accuracy, area under the receiver operating characteristic (AUROC), and F1 score by 11.9%, 11.3%, and 13.6%, respectively. For the random forest-based model, the accuracy, AUROC, and F1 score were 0.692, 0.753, and 0.602, respectively.

CONCLUSIONS

We showed that lab tests and medication relationships can be used as efficient features for predicting sepsis in patients with cancer. Consequently, identifying the risk of sepsis in patients with cancer using EHRs and machine learning is feasible.