Sepsis biomarkers: a review

Presepsin and prognostic nutritional index are predictors of septic acute kidney injury, renal replacement therapy initiation in sepsis patients, and prognosis in septic acute kidney injury patients: a pilot study

Background

Sepsis is the most common cause of acute kidney injury (AKI) among critically ill patients. This study aimed to determine whether presepsin is a predictor of septic acute kidney injury, renal replacement therapy initiation (RRTi) in sepsis patients, and prognosis in septic AKI patients.

Methods

Presepsin values were measured immediately after ICU admission (baseline) and on Days 2, 3, and 5 after ICU admission. Glasgow Prognostic Score (GPS), neutrophil to lymphocyte ratio (NLR), platelet to lymphocyte ratio, Prognostic Index, and Prognostic Nutritional Index (PNI) were measured at baseline, and total scores (“inflammation-presepsin scores [iPS]”) were calculated for category classification. Presepsin values, inflammation-based prognostic scores, and iPS were compared between patients with and without septic AKI or RRTi and between survivors and non-survivors.

Results

Receiver operating characteristic curve analyses identified the following variables as predictors of septic AKI and RRTi in sepsis patients: presepsin on Day 1 (AUC: 0.73) and Day 2 (AUC: 0.71) for septic AKI, and presepsin on Day 1 (AUC: 0.71), Day 2 (AUC: 0.9), and Day 5 (AUC: 0.96), Δpresepsin (Day 2 – Day 1) (AUC: 0.84), Δpresepsin (Day 5 – Day 1) (AUC: 0.93), and PNI (AUC: 0.72) for RRTi. Multivariate logistic regression analyses identified presepsin on Day 2 as a predictor of prognosis in septic AKI patients.

Conclusions

Presepsin and PNI were found to be predictors of septic AKI, RRTi in sepsis patients, and prognosis in septic AKI patients.

Endothelial Dysfunction and Neutrophil Degranulation as Central Events in Sepsis Physiopathology

Sepsis is a major health problem worldwide. It is a time-dependent disease, with a high rate of morbidity and mortality. In this sense, an early diagnosis is essential to reduce these rates. The progressive increase of both the incidence and prevalence of sepsis has translated into a significant socioeconomic burden for health systems. Currently, it is the leading cause of noncoronary mortality worldwide and represents one of the most prevalent pathologies both in hospital emergency services and in intensive care units. In this article, we review the role of both endothelial dysfunction and neutrophil dysregulation in the physiopathology of this disease. The lack of a key symptom in sepsis makes it difficult to obtain a quick and accurate diagnosis of this condition. Thus, it is essential to have fast and reliable diagnostic tools. In this sense, the use of biomarkers can be a very important alternative when it comes to achieving these goals. Both new biomarkers and treatments related to endothelial dysfunction and neutrophil dysregulation deserve to be further investigated in order to open new venues for the diagnosis, treatment and prognosis of sepsis.

Accuracy of Heparin-Binding Protein in Diagnosing Sepsis: A Systematic Review and Meta-Analysis

OBJECTIVES

Existing studies evaluating the accuracy of heparin-binding protein for the diagnosis of sepsis have been inconsistent. We conducted a systematic review and meta-analysis to assess the totality of current evidence regarding the utility of heparin-binding protein to diagnose sepsis in patients with presumed systemic infection.

DATA SOURCE

PubMed, Embase, the China National Knowledge infrastructure, and WangFang electronic database were searched from inception to December of 2019.

STUDY SELECTION

Two independent reviewers identified eligible studies. Cohort and case-control studies, which measured serum levels of heparin-binding protein among adult patients with suspected sepsis, were eligible for inclusion.

DATA EXTRACTION

Two reviewers independently extracted data elements from the selected studies. A bivariate random-effects meta-analysis model was used to synthesize the prognostic accuracy measures. Risk of bias of studies was assessed with Quality Assessment of Diagnostic Accuracy Studies 2 tool.

DATA SYNTHESIS

We identified 26 studies with 3,868 patients in the meta-analysis. Heparin-binding protein had a pooled sensitivity of 0.85 (95% CI, 0.79-0.90) and a pooled specificity of 0.91 (95% CI, 0.82-0.96) for the diagnosis of sepsis. There was low heterogeneity between the studies (I2 = 12%), and no evidence of publication bias was detected. Heparin-binding protein had a higher sensitivity and specificity when compared with procalcitonin (0.75 [95% CI, 0.62-0.85] and 0.85 [95% CI, 0.73-0.92]) as well as C-reactive protein (0.75 [95% CI, 0.65-0.84] and 0.71 [95% CI, 0.63-0.77]). Serial measurements of heparin-binding protein also showed that heparin-binding protein levels rose significantly at least 24 hours before a diagnosis of sepsis.

CONCLUSIONS

The diagnostic ability of heparin-binding protein is favorable, demonstrating both high sensitivity and specificity in predicting progression to sepsis in critically ill patients. Future studies could assess the incremental value that heparin-binding protein may add to a multimodal sepsis identification and prognostication algorithm for critically ill patients.

Thyroid hormone disorders: a predictor of mortality in patients with septic shock defined by Sepsis-3?

Decreased serum thyroid hormone levels and their prediction of mortality in septic patients are still controversial, especially with the evolution of the definition of sepsis. This study aimed to assess the ability of thyroid hormone disorders to predict the early mortality of patients with septic shock defined by Sepsis-3. Sixty-three adult patients with septic shock admitted to a university hospital emergency intensive care unit (EICU) were studied. Serum free T3 (FT3), free T4 (FT4), thyroid stimulating hormone (TSH), C-reactive protein (CRP), procalcitonin (PCT), and lactate levels were determined and compared with survival status and organ dysfunction. Among the 63 patients studied, lower serum FT3 and FT4 levels were significantly associated with higher sequential organ failure assessment (SOFA) scores. Patients with septic shock with lower levels of FT3 (≤ 1.70 pmol/L) and FT4 (≤ 9.99 pmol/L) had significantly increased 28-day mortality. There was no significant difference in the serum TSH level between the survivor and nonsurvivor groups. The areas under the receiver operating characteristic curves for FT3 and FT4 levels were associated with 28-day mortality (0.92 and 0.89, respectively) and were higher than that for SOFA (0.82), CRP (0.65) and lactate (0.59). The decrease in serum levels of FT3 and FT4 in patients with septic shock is associated with the severity of organ dysfunction and 28-day mortality. Early detection of serum FT3 and FT4 levels could help clinicians to identify patients at high risk of clinical deterioration.

Accuracy of pancreatic stone protein for the diagnosis of infection in hospitalized adults: a systematic review and individual patient level meta-analysis

Background

Accurate biomarkers to diagnose infection are lacking. Studies reported good performance of pancreatic stone protein (PSP) to detect infection. The objective of the study was to determine the performance of PSP in diagnosing infection across hospitalized patients and calculate a threshold value for that purpose.

Methods

A systematic search across Cochrane Central Register of Controlled Trials and MEDLINE databases (1966–March 2019) for studies on PSP published in English using ‘pancreatic stone protein’, ‘PSP’, ‘regenerative protein’, ‘lithostatin’ combined with ‘infection’ and ‘sepsis’ found 44 records. The search was restricted to the five trials that evaluated PSP for the initial detection of infection in hospitalized adults. Individual patient data were obtained from the investigators of all eligible trials. Data quality and validity was assessed according to PRISMA guidelines. We choose a fixed-effect model to calculate the PSP cut-off value that best discriminates infected from non-infected patients.

Results

Infection was confirmed in 371 of 631 patients. The median (IQR) PSP value of infected versus uninfected patients was 81.5 (30.0–237.5) versus 19.2 (12.6–33.57) ng/ml, compared to 150 (82.70–229.55) versus 58.25 (15.85–120) mg/l for C-reactive protein (CRP) and 0.9 (0.29–4.4) versus 0.15 (0.08–0.5) ng/ml for procalcitonin (PCT). Using a PSP cut-off of 44.18 ng/ml, the ROC AUC to detect infection was 0.81 (0.78–0.85) with a sensitivity of 0.66 (0.61–0.71), specificity of 0.83 (0.78–0.88), PPV of 0.85 (0.81–0.89) and NPV of 0.63 (0.58–0.68). When a model combining PSP and CRP was used, the ROC AUC improved to 0.90 (0.87–0.92) with higher sensitivity 0.81 (0.77–0.85) and specificity 0.84 (0.79–0.90) for discriminating infection from non-infection. Adding PCT did not improve the performance further.

Conclusions

PSP is a promising biomarker to diagnose infections in hospitalized patients. Using a cut-off value of 44.18 ng/ml, PSP performs better than CRP or PCT across the considered studies. The combination of PSP with CRP further enhances its accuracy.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13054-021-03609-2.

A systematic review of biomarkers associated with maternal infection in pregnant and postpartum women

BACKGROUND

Serum biomarkers are commonly used to support the diagnosis of infection in non-pregnant patients whose clinical presentation suggests infection. The utility of serum biomarkers for infection in pregnant and postpartum women is uncertain.

SEARCH STRATEGY

PubMed, CINAHL, EMBASE, ClinicalTrials.gov, Cochrane Library, CINAHL, and SCOPUS were searched from inception to February 2020.

SELECTION CRITERIA

Full-text manuscripts in English were included if they reported the measurement of maternal serum biomarkers-and included a control group-to identify infection in pregnant and postpartum women.

DATA COLLECTION AND ANALYSIS

two authors independently screened manuscripts, extracted data, and assessed methodologic quality.

MAIN RESULTS

Interleukin-6 (IL-6), C-reactive protein, procalcitonin, insulin-like growth factor binding protein 1, tumor necrosis factor-α, calgranulin B, neopterin, and interferon-γ inducible protein 10 reliably indicated infection. Intercellular adhesion molecule 1, monocyte chemotactic and activating factor, soluble IL-6 receptor, and IL-8 were not useful markers in pregnant and postpartum women.

CONCLUSIONS

Findings suggest that certain biomarkers have diagnostic value when maternal infection is suspected, but also confirms limitations in this population.

Serum-soluble PD-L1 may be a potential diagnostic biomarker in sepsis

To investigate whether serum-soluble PD-L1 (sPD-L1) is a potential biomarker for identifying sepsis. This study enrolled 64 septic patients, 29 patients with acute appendicitis, 33 patients with acute pancreatitis and 30 healthy volunteers. Sepsis was defined according to the Sepsis 3.0 criteria.[1] The associated clinical parameters were recorded, blood samples were collected on the first day of diagnosis, and serum sPD-L1 levels were measured using enzyme-linked immunosorbent assays. Compared with the control group, a significant increase in sPD-L1 levels was observed in patients with sepsis (n = 64). Increased sPD-L1 expression correlated strongly with increased clinical inflammatory values (CRP, PCT and WBC) and decreased immunological functional parameters (CD3⁺ , CD4⁺ and CD8⁺ cell counts). The area under the ROC curve (AUC) for sPD-L1 in combination with the sequential organ failure assessment (SOFA) score was superior to the AUC for either sPD-L1 or SOFA score in regard to the diagnosis of sepsis. sPD-L1 may represent a valuable biomarker for the diagnosis of sepsis.

The Prognostic Value of Presepsin for Sepsis in Abdominal Surgery: A Prospective Study

INTRODUCTION

Rapid diagnosis accompanied by appropriate treatment is essential in the therapy of sepsis. However, there is no blood marker available, which reliably predicts sepsis and associated mortality. Therefore, the aim of the present study was to evaluate presepsin and endotoxin in comparison with established blood markers in patients undergoing emergency visceral surgery for abdominal infection.

PATIENTS AND METHODS

This prospective study included 31 patients with abdominal infection undergoing emergency surgery between March and August 2014. The Sepsis-2 and Sepsis-3 definitions of sepsis were used. Blood markers (presepsin, endotoxin, C-reactive protein, procalcitonin (PCT), interleukin 6 (IL-6), white blood count) were analyzed preoperatively and correlated with the clinical course and mortality. Additionally, a combination of the three markers, which performed best, was tested.

RESULTS

Twenty patients (64.5%) in the analyzed cohort developed sepsis from an abdominal focus according to the latest sepsis definition. Out of the analyzed blood markers, presepsin exhibited the highest area under the curve, sensitivity, and specificity for the prediction of the development of sepsis. Moreover, presepsin had the highest predictive value for mortality as opposed to both endotoxin and previously established blood markers (i.e., PCT, IL-6). The multimarker approach, which included PCT, IL-6, and presepsin, showed no additional predictive value over presepsin alone.

CONCLUSION

The present study suggests that presepsin is a novel predictor of sepsis and mortality from sepsis in patients undergoing surgery for intra-abdominal infections. The findings of the present study should be validated in a larger cohort.

An on-chip microfluidic-based electrochemical magneto-immunoassay for the determination of procalcitonin in plasma obtained from sepsis diagnosed preterm neonates

A novel on-chip electrochemical magneto-immunoassay for the determination of procalcitonin (PCT) has been proposed. The strategy involved the on-line performing of the biorecognition event and detection on the thin-film microfluidic gold electrode chamber operating at E = -0.20 V (vs. Au). The complete assay was performed in less than 15 minutes using only 25 μL of the sample, covering the entire range of clinically relevant PCT concentrations in sepsis diagnosis with a limit of detection and quantification of 0.02 ng mL-1 and 0.05 ng mL-1, respectively (the sepsis diagnosis threshold: 0.5 ng mL-1). The on-chip electrochemical magneto-immunoassay provided excellent results in the analysis of very unique samples obtained from preterm neonates admitted with suspected sepsis, in which the sample volume is hardly available. These characteristics fulfill the POCT requirements for PCT determination in the whole clinically relevant concentration range. Because of the high clinical relevance and the important role of PCT in sepsis, this approach opens new perspectives for sepsis diagnosis and therapy guidance using low volume samples.

Long Noncoding RNA: Regulatory Mechanisms and Therapeutic Potential in Sepsis

Sepsis is a life-threatening organ dysfunction caused by a dysregulated host response to infection and is characterized by a hyperinflammatory state accompanied by immunosuppression. Long noncoding RNAs (lncRNAs) are noncoding RNAs longer than 200 nucleotides and have important roles in mediating various biological processes. Recently, lncRNAs were found to exert both promotive and inhibitory immune functions in sepsis, thus participating in sepsis regulation. Additionally, several studies have revealed that lncRNAs are involved in sepsis-induced organ dysfunctions, including cardiovascular dysfunction, acute lung injury, and acute kidney injury. Considering the lack of effective biomarkers for early identification and specific treatment for sepsis, lncRNAs may be promising biomarkers and even targets for sepsis therapies. This review systematically highlights the recent advances regarding the roles of lncRNAs in sepsis and sheds light on their use as potential biomarkers and treatment targets for sepsis.

Post-Cardiac Arrest Hydrocortisone Use Ameliorates Cardiac Mitochondrial Injury in a Male Rat Model of Ventricular Fibrillation Cardiac Arrest

Background

Steroid use after cardiac arrest has been reported to improve survival and neurological outcome in cardiac arrest survivors. The study aimed to evaluate the effect of post‐arrest hydrocortisone use on myocardial damage and cardiac mitochondrial injury in a rat model of ventricular fibrillation cardiac arrest.

Methods and Results

Ventricular fibrillation cardiac arrest was induced and left untreated for 5 minutes in adult male Wistar rats. Cardiopulmonary resuscitation and electric shocks were then applied to achieve return of spontaneous circulation (ROSC). Successfully resuscitated animals were randomized into 3 groups: control, low‐dose hydrocortisone (2 mg/kg), and high‐dose hydrocortisone (8 mg/kg). The low‐dose hydrocortisone and high‐dose hydrocortisone (treatment) groups received intravenous hydrocortisone immediately after ROSC and the control group received saline as placebo. Each group consisted of 15 animals. Within 4 hours of ROSC, both treatment groups showed a higher cardiac output than the control group. At the fourth hour following ROSC, histological examination and transmission electron microscopy demonstrated less myocardial damage and mitochondrial injury in the animals treated with hydrocortisone. In the treatment groups, hydrocortisone mitigated the acceleration of Ca²⁺‐induced mitochondrial swelling and suppression of complex activity observed in the control group. At the 72nd hour after ROSC, a significantly higher proportion of animals treated with hydrocortisone survived and had good neurological recovery compared with those given a placebo.

Conclusions

Hydrocortisone use after cardiac arrest may mitigate myocardial injury and cardiac mitochondrial damage and thus improve survival, neurological and histological outcomes in a rat model of ventricular fibrillation cardiac arrest.

Early Warning of Infection in Patients Undergoing Hematopoietic Stem Cell Transplantation Using Heart Rate Variability and Serum Biomarkers

Early warning of infection is critical to reduce the risk of deterioration and mortality, especially in neutropenic patients following hematopoietic stem cell transplantation (HCT). Given that heart rate variability (HRV) is a sensitive and early marker for infection, and that serum inflammatory biomarkers can have high specificity for infection, we hypothesized their combination may be useful for accurate early warning of infection. In this study, we developed and evaluated a composite predictive model using continuous HRV with daily serum biomarker measurements to provide risk stratification of future deterioration in HCT recipients. A total of 116 ambulatory outpatients about to undergo HCT consented to collection of prospective demographic, clinical (daily vital signs), HRV (continuous electrocardiography [ECG] monitoring, laboratory [daily serum samples frozen at -80 °C]), and infection outcome variables (defined as the time of escalation of antibiotics), all from 24 hours pre-HCT to the onset of infection or 14 days post-HCT. Indications for antibiotic escalation were adjudicated as "true infection" or not by 2 blinded HCT clinicians. A composite time series of 8 HRV metrics was created for each patient, and the probability of deterioration within the next 72 hours was estimated using logistic regression modeling of composite HRV and serum biomarkers using a rule-based naïve Bayes model if the HRV-based probability exceeded a median threshold. Thirty-five patients (30%) withdrew within <24 hours owing to intolerability of ECG monitoring, leaving 81 patients, of whom 48 (59%) had antibiotic escalation adjudicated as true infection. The combined HRV and biomarker (TNF-α, IL-6, and IL-7) predictive model began increasing at ∼48 hours on average before the diagnosis of infection, could distinguish between high risk of impending infection (>90% incidence of subsequent infection within 72 hours), average risk (∼50%), and low risk (<10%), with an area under the receiver operating characteristic curve of 0.87. However, given that prophylactic predictive ECG monitoring and daily serum collection proved challenging for many patients, further refinement in measurement is necessary for further study.

Association of plasma level of high-mobility group box-1 with necroptosis and sepsis outcomes

The role of high-mobility group box-1 (HMGB1) in outcome prediction in sepsis is controversial. Furthermore, its association with necroptosis, a programmed cell necrosis mechanism, is still unclear. The purpose of this study is to identify the association between the plasma levels of HMGB1 and the severity and clinical outcomes of sepsis, and to examine the correlation between HMGB1 and key executors of necroptosis including receptor-interacting kinase 3 (RIPK3) and mixed lineage kinase domain-like- (MLKL) proteins. Plasma HMGB1, RIPK3, and MLKL levels were measured with the enzyme-linked immunosorbent assay from the derivation cohort of 188 prospectively enrolled, critically-ill patients between April 2014 and December 2016, and from the validation cohort of 77 patients with sepsis between January 2017 and January 2019. In the derivation cohort, the plasma HMGB1 levels of the control (n = 46, 24.5%), sepsis (n = 58, 30.9%), and septic shock (n = 84, 44.7%) groups were significantly increased (P < 0.001). A difference in mortality between high (≥ 5.9 ng/mL) and low (< 5.9 ng/mL) HMGB1 levels was observed up to 90 days (Log-rank test, P = 0.009). There were positive linear correlations of plasma HMGB1 with RIPK3 (R² = 0.61, P < 0.001) and MLKL (R² = 0.7890, P < 0.001). The difference in mortality and correlation of HMGB1 levels with RIPK3 and MLKL were confirmed in the validation cohort. Plasma levels of HMGB1 were associated with the severity and mortality attributed to sepsis. They were correlated with RIPK3 and MLKL, thus suggesting an association of HMGB1 with necroptosis.

Diagnostic Accuracy of Procalcitonin and C-reactive Protein Is Insufficient to Predict Proven Infection: A Retrospective Cohort Study in Critically Ill Patients Fulfilling the Sepsis-3 Criteria

BACKGROUND

New Sepsis-3 definitions facilitate early recognition of patients with sepsis. In this study we investigated whether a single initial determination of procalcitonin (PCT) or C-reactive protein (CRP) in plasma can predict proven sepsis in Sepsis-3 criteria-positive critically ill patients. We also investigated whether a decline in serial PCT or CRP can predict outcome in 28-day mortality.

METHODS

Patients, ≥18 years of age, at the intensive care unit with a suspected infection, a Sequential Organ Failure Assessment (SOFA) score of ≥2 points, and an index test PCT and CRP at admission were selected from a prospectively collected cohort. PCT and CRP were studied retrospectively with the Mann-Whitney U-test and ROC analysis.

RESULTS

In total, 157 patients were selected; 63 of the 157 had proven sepsis, and sepsis could not be detected in 94 of the 157. Neither a single PCT nor CRP at admission was able to discriminate proven sepsis from nonproven sepsis (PCT, 1.8 μg/L and 1.5 μg/L, respectively, P = 0.25; CRP, 198 mg/L and 186 mg/L, respectively, P = 0.53). Area under the curve for both PCT and CRP for detecting proven sepsis was low (0.55 and 0.53). Furthermore, neither a decline from baseline to day 5 PCT nor CRP could predict 28-day mortality (PCT, 50% vs 46%, P = 0.83; CRP, 30% vs 40%, P = 0.51).

CONCLUSION

PCT and CRP at admission were not able to discern patients with proven sepsis in Sepsis-3 criteria-positive critically ill patients. A decline of PCT and CRP in 5 days was not able to predict 28-day mortality.

The potential of FT-IR spectroscopy for improving healthcare in sepsis - An animal model study

Fourier Transform-Infrared (FT-IR) absorption spectroscopy has been used to investigate pathophysiological changes caused by sepsis. Sepsis has been defined as a potentially fatal organic dysfunction caused by a dysregulated host response to infection and can lead a patient to risk of death. This study used samples consisting of the blood plasma of mice which were induced to sepsis state, compared to a healthy group using FT-IR associated with attenuated total reflectance (ATR) spectroscopy. For statistical analysis, principal components analysis (PCA) and linear discriminant analysis (LDA) were applied, independently, to the second derivative spectra of both the fingerprint (900-1800 cm^-1) and the high wavenumber (2800-3100 cm^-1) regions. The technique efficiently differentiated the blood plasma of the two groups, sepsis and healthy mice, the analysis indicating that fatty acids and lipids in the blood samples could be an important biomarker of sepsis.

Targeting STAT3: A crucial modulator of sepsis

Signal transducer and activator of transcription 3 (STAT3) is a cellular signal transcription factor that has recently attracted a great deal of attention. It can trigger a variety of genes transcription in response to cytokines and growth factors stimulation, which plays an important role in many cellular biological processes involved in anti/proinflammatory responses. Sepsis is a life-threatening organ dysfunction resulting from dysregulated host responses to infection. As a converging point of multiple inflammatory responses pathways, accumulating studies have presented the elaborate network of STAT3 in sepsis pathophysiology; these results generally indicate a promising therapeutic application for targeting STAT3 in the treatment of sepsis. In the present review, we evaluated the published literature describing the use of STAT3 in the treatment of experimental and clinical sepsis. The information presented here may be useful for the design of future studies and may highlight the potential of STAT3 as a future biomarker and therapeutic target for sepsis.

Monocyte distribution width compared with C-reactive protein and procalcitonin for early sepsis detection in the emergency department

PURPOSE

Monocyte distribution width (MDW) has been suggested as an early biomarker of sepsis, but few studies have compared MDW with conventional biomarkers, including C-reactive protein (CRP) and procalcitonin (PCT). This study evaluated MDW as a biomarker for sepsis and compared it with CRP and PCT.

MATERIALS AND METHODS

Patients aged 18-80 years who visited the emergency department were screened and prospectively enrolled in a tertiary medical center. Complete blood count, MDW, CRP, and PCT were examined. Diagnostic performance for sepsis was tested using the area under the curve (AUC) of receiver operating characteristic (ROC) curves, sensitivity, and specificity.

RESULTS

In total, 665 patients were screened, and 549 patients with valid laboratory test results were included in the analysis. The patients were categorized into three groups according to the Sepsis-3 criteria: non-infection, infection, and sepsis. MDW showed the highest value in the sepsis group (median [interquartile range], 24.0 [20.8-27.8]). The AUC values for MDW, CRP, PCT, and white blood cells for predicting sepsis were 0.71 (95% confidence interval [CI], 0.67-0.75), 0.75 (95% CI, 0.71-0.78], 0.76 (95% CI, 0.72-0.79, and 0.61 (95% CI, 0.57-0.65), respectively. With the optimal cutoff value of the cohort, the sensitivity was 83.0% for MDW (cutoff, 19.8), 69.7% for CRP (cutoff, 4.0), and 76.6% for PCT (cutoff, 0.05). The combination of quick Sequential Organ Failure Assessment (qSOFA) with MDW improved the AUC (0.76; 95% CI, 0.72-0.80) to a greater extent than qSOFA alone (0.67; 95% CI, 0.62-0.72).

CONCLUSIONS

MDW reflected a diagnostic performance comparable to that of conventional diagnostic markers, implying that MDW is an alternative biomarker. The combination of MDW and qSOFA improves the diagnostic performance for early sepsis.

Macrophage migration inhibitory factor as a diagnostic and predictive biomarker in sepsis: meta-analysis of clinical trials

The hunt for useful sepsis biomarkers is ongoing. Macrophage migration inhibitory factor (MIF) was implicated as a biomarker in sepsis, but its diagnostic and prognostic value has remained unclear in human studies. Here, we aimed at clarifying the value of MIF as a sepsis biomarker with the meta-analysis of clinical trials. PubMed, EMBASE, and Cochrane Central Register of Controlled Trials databases were searched until December 2019. From the included studies, blood MIF levels and indicators of disease severity were extracted in septic and control patient groups. Twenty-one eligible studies were identified, including data from 1876 subjects (of which 1206 had sepsis). In the septic patients, blood MIF levels were significantly higher than in healthy controls with a standardized mean difference (SMD) of 1.47 (95% confidence interval, CI: 0.96-1.97; p < 0.001) and also higher than in patient groups with nonseptic systemic inflammation (SMD = 0.94; CI: 0.51-1.38; p < 0.001). Markedly greater elevation in blood MIF level was found in the more severe forms of sepsis and in nonsurvivors than in less severe forms and in survivors with SMDs of 0.84 (CI: 0.45-1.24) and 0.75 (CI: 0.40-1.11), respectively (p < 0.001 for both). In conclusion, blood MIF level is more elevated in systemic inflammation caused by infection (i.e., sepsis) compared to noninfectious causes. In more severe forms of sepsis, including fatal outcome, MIF levels are higher than in less severe forms. These results suggest that MIF can be a valuable diagnostic and prognostic biomarker in sepsis given that well-designed clinical trials validate our findings.

Microfluidics for sepsis early diagnosis and prognosis: a review of recent methods

Sepsis is a complex disorder of immune system response to infections that can be caused by a wide range of clinical contexts. Traditional methods for sepsis detection include molecular diagnosis, biomarkers either based on protein concentration or cell surface expression, and microbiological cultures. Development of point-of-care (POC) instruments, which can provide high accuracy and consume less time, is in unprecedented demand. Within the past few years, applications of microfluidic systems for sepsis detection have achieved excellent performance. In this review, we discuss the most recent microfluidic applications specifically in sepsis detection, and propose their advantages and disadvantages. We also present a comprehensive review of other traditional and current sepsis diagnosis methods to obtain a general understanding of the present conditions, which can hopefully direct the development of a new sepsis roadmap.

Case Report: Interferon-γ Restores Monocytic Human Leukocyte Antigen Receptor (mHLA-DR) in Severe COVID-19 With Acquired Immunosuppression Syndrome

Background

The major histocompatibility complex (MHC) class II characterized by monocytes CD14+ expression of human leukocyte antigen receptors (HLA-DR), is essential for the synapse between innate and adaptive immune response in infectious disease. Its reduced expression is associated with a high risk of secondary infections in septic patients and can be safely corrected by Interferon-y (IFNy) injection. Coronavirus disease (COVID-19) induces an alteration of Interferon (IFN) genes expression potentially responsible for the observed low HLA-DR expression in circulating monocytes (mHLA-DR).

Methods

We report a case of one-time INFy injection (100 mcg s.c.) in a superinfected 61-year-old man with COVID-19–associated acute respiratory distress syndrome (ARDS), with monitoring of mHLA-DR expression and clinical tolerance.

Observations

Low mHLA-DR pretreatment expression (26.7%) was observed. IFNy therapy leading to a rapid increase in mHLA-DR expression (83.1%).

Conclusions

Severe ARDS in a COVID-19 patient has a deep reduction in mHLA-DR expression concomitantly with secondary infections. The unique IFNy injection was safe and led to a sharp increase in the expression of mHLA-DR. Based on immune and infection monitoring, more cases of severe COVID-19 patients with low mHLA-DR should be treated by IFNy to test the clinical effectiveness.

HIPK3 Mediates Inflammatory Cytokines and Oxidative Stress Markers in Monocytes in a Rat Model of Sepsis Through the JNK/c-Jun Signaling Pathway

Sepsis is a fetal immunological disorder and its complication worsens in the patients with hemodialysis which may increase the risk of death. In the present study, we aimed to investigate the effect of homeodomain-interacting protein kinase 3 (HIPK3) on inflammatory factors and oxidative stress markers in monocytes of rats with sepsis by regulating the c-Jun amino-terminal kinase (JNK)/c-Jun signaling pathway. A rat model of sepsis was initially established using cecal ligation and puncture (CLP) and was further identified by enlarged spleen tissues, inflammation, and oxidative stress. Monocytes were isolated from rats with CLP-induced sepsis. HIPK3 was observed to be downregulated while JUN was upregulated in monocytes from rats with CLP-induced sepsis. Furthermore, isolated monocytes were transduced with lentiviral vectors expressing HIPK3 or shRNA against HIPK3 to explore the effect of HIPK3 on viability and apoptosis of monocytes as well as inflammatory factors and oxidative stress markers. The obtained data exhibited that overexpression of HIPK3 or inhibition of the JNK signaling pathway enhanced proliferation, reduced apoptosis of monocytes, alleviated inflammation, and oxidative stress injury. Consistently, our results may provide evidence that HIPK3 could inhibit the JNK/c-Jun signaling pathway, thereby potentially retarding the progression of sepsis.

Research progress of circRNA as a biomarker of sepsis: a narrative review

Objective

Explore the possibility of circRNAs as markers of sepsis.

Background

Sepsis is an abnormal immune response of our body to infection that can lead to organ failure and death. Although the research on sepsis has been extensive in the past few years, sepsis-associated morbidity and mortality are still increasing. Early diagnosis and early treatment are important for patients with sepsis. Although many markers, including procalcitonin and C-reactive protein, have been proposed as diagnostic indicators of sepsis, there are still challenges in the early diagnosis and treatment of sepsis due to the lack of sensitivity and specificity of these substances. Recently, a large number of studies have found that circular RNAs (circRNAs) participate in a variety of biological functions, such as immune response, regulating the expression of miRNAs, and they are closely related to the occurrence and development of many diseases, including sepsis. However, the clear mechanism of the role of circRNAs has not been fully elucidated. An increasing number of studies have confirmed that circRNAs have potential in the diagnosis and treatment of sepsis. By studying the regulatory mechanism of circRNAs in sepsis, we can search for new molecular intervention targets for the treatment of sepsis, which is conducive to the development of new molecular therapeutic drugs for sepsis.

Methods

In the present study, we summarize and analyze the role of circRNAs in the pathogenesis of sepsis and discuss the possibility of circRNA as a biomarker for the diagnosis of sepsis.

Conclusions

The biological characteristics of circRNAs and their role in the occurrence and development of sepsis make them possible markers of sepsis.

High Inter-Patient Variability in Sepsis Evolution: A Hidden Markov Model Analysis

BACKGROUND

Severe sepsis and septic shock are common in the intensive care unit (ICU) and contribute significantly to cost and mortality. Early treatment is critical but is confounded by the difficulty of real-time diagnosis. This study uses hidden Markov models (HMMs) to examine whether the time evolution of sepsis can add diagnostic accuracy or value using a proven set of bio-signals.

METHODS

Clinical data (N=36 patients; 6071 hours), including an hourly personalised insulin sensitivity metric. A two hidden state HMM is created to discriminate diagnosed cases (Severe Sepsis, Septic Shock) from controls (SIRS, Sepsis) states. Diagnostic performance is measured by ROC curves, likelihood ratios (LHRs), sensitivity/specificity, and diagnostic odds-ratios (DOR), for a best-case resubstitution estimate and a worst-case 80/20% repeated holdout analysis.

RESULTS

The HMM delivered near perfect results (95% Sensitivity; 96% Specificity) for best-case resubstitution estimates, but was comparatively poor (59% Sensitivity; 61% Specificity) for worst-case repeated holdout estimations. Adding the time evolution of sepsis did not add to the accuracy of diagnosis from using the signals alone without time history.

CONCLUSIONS

These potentially surprising results indicate significant inter-patient variability in the time evolution of sepsis, preventing effective diagnosis in the context of the bio-signals, data, and HMM topology used. Efforts for improved real-time, early sepsis diagnosis should concentrate on the robustness and efficacy of the bio-signals and data used, as well as the level of model complexity, to create more effective real-time classifiers.

Understanding and Managing Sepsis in Patients With Cancer in the Era of Antimicrobial Resistance

Sepsis is a frequent complication in immunosuppressed cancer patients and hematopoietic stem cell transplant recipients that is associated with high morbidity and mortality rates. The worldwide emergence of antimicrobial resistance is of special concern in this population because any delay in starting adequate empirical antibiotic therapy can lead to poor outcomes. In this review, we aim to address: (1) the mechanisms involved in the development of sepsis and septic shock in these patients; (2) the risk factors associated with a worse prognosis; (3) the impact of adequate initial empirical antibiotic therapy given the current era of widespread antimicrobial resistance; and (4) the optimal management of sepsis, including adequate and early source control of infection, optimized antibiotic use based on the pharmacokinetic and pharmacodynamics changes in these patients, and the role of the new available antibiotics.

Serum Heparin-Binding Protein as a Potential Biomarker to Distinguish Adult-Onset Still's Disease From Sepsis

Adult-onset Still’s disease (AOSD) is a systemic, multifactorial, autoinflammatory disease for which the etiopathogenesis is not well understood. Given the similarities in clinical and laboratory features between this disease and sepsis, and the differences in treatment strategies for these two diseases, specific diagnostic markers are crucial for the correct diagnosis and management of AOSD. Previous studies have shown plasma heparin-binding protein (HBP) is a promising potential biomarker for AOSD; thus, this study aimed to detect serum HBP levels in patients with AOSD or sepsis to assess its potential as a biomarker for differential diagnosis. We found that serum HBP levels were significantly higher in patients with active AOSD than that in those with inactive AOSD. Patients with sepsis had higher serum HBP levels compared with those who had active or inactive AOSD. We calculated the area under the receiver operating characteristic (ROC) curve to assess whether HBP could be used to differentiate active from inactive AOSD; this was 0.811 with sensitivity 0.650, specificity 0.811, and cutoff HBP value of 35.59 ng/ml. The area under the ROC curve for HBP as a biomarker to differentiate AOSD from sepsis was 0.653, with sensitivity 0.759, and specificity 0.552, and cutoff HBP value of 65.1 ng/ml. Taken together, the results of our study suggest that serum HBP could be a useful diagnostic biomarker to evaluate disease activity in patients with AOSD, and to differentiate AOSD from sepsis.

Periodontal Pathogens and Neuropsychiatric Health

Increasing evidence incriminates low-grade inflammation in cardiovascular, metabolic diseases, and neuropsychiatric clinical conditions, all important causes of morbidity and mortality. One of the upstream and modifiable precipitants and perpetrators of inflammation is chronic periodontitis, a polymicrobial infection with Porphyromonas gingivalis (P. gingivalis) playing a central role in the disease pathogenesis. We review the association between P. gingivalis and cardiovascular, metabolic, and neuropsychiatric illness, and the molecular mechanisms potentially implicated in immune upregulation as well as downregulation induced by the pathogen. In addition to inflammation, translocation of the pathogens to the coronary and peripheral arteries, including brain vasculature, and gut and liver vasculature has important pathophysiological consequences. Distant effects via translocation rely on virulence factors of P. gingivalis such as gingipains, on its synergistic interactions with other pathogens, and on its capability to manipulate the immune system via several mechanisms, including its capacity to induce production of immune-downregulating micro-RNAs. Possible targets for intervention and drug development to manage distal consequences of infection with P. gingivalis are also reviewed.

Hyperbaric oxygen treatment is associated with a decrease in cytokine levels in patients with necrotizing soft-tissue infection

BACKGROUND

The pathophysiological understanding of the inflammatory response in necrotizing soft-tissue infection (NSTI) and its impact on clinical progression and outcomes are not resolved. Hyperbaric oxygen (HBO₂ ) treatment serves as an adjunctive treatment; however, its immunomodulatory effects in the treatment of NSTI remains unknown. Accordingly, we evaluated fluctuations in inflammatory markers during courses of HBO₂ treatment and assessed the overall inflammatory response during the first 3 days after admission.

METHODS

In 242 patients with NSTI, we measured plasma TNF-α, IL-1β, IL-6, IL-10, and granulocyte colony-stimulating factor (G-CSF) upon admission and daily for three days, and before/after HBO² in the 209 patients recieving HBO² . We assessed the severity of disease by Simplified Acute Physiology Score (SAPS) II, SOFA score, and blood lactate.

RESULTS

In paired analyses, HBO₂ treatment was associated with a decrease in IL-6 in patients with Group A-Streptococcus NSTI (first HBO₂ treatment, median difference -29.5 pg/ml; second HBO₂ treatment, median difference -7.6 pg/ml), and overall a decrease in G-CSF (first HBO₂ treatment, median difference -22.5 pg/ml; 2^- HBO₂ treatment, median difference -20.4 pg/ml). Patients presenting with shock had significantly higher baseline cytokines values compared to non-shock patients (TNF-α: 51.9 vs. 23.6, IL-1β: 1.39 vs 0.61, IL-6: 542.9 vs. 57.5, IL-10: 21.7 vs. 3.3 and G-CSF: 246.3 vs. 11.8 pg/ml; all p < 0.001). Longitudinal analyses demonstrated higher concentrations in septic shock patients and those receiving renal-replacement therapy. All cytokines were significantly correlated to SAPS II, SOFA score, and blood lactate. In adjusted analysis, high baseline G-CSF was associated with 30-day mortality (OR 2.83, 95% CI: 1.01-8.00, p = 0.047).

CONCLUSION

In patients with NSTI, HBO₂ treatment may induce immunomodulatory effects by decreasing plasma G-CSF and IL-6. High levels of inflammatory markers were associated with disease severity, whereas high baseline G-CSF was associated with increased 30-day mortality.

Immune Profiling Panel: A Proof-of-Concept Study of a New Multiplex Molecular Tool to Assess the Immune Status of Critically Ill Patients

BACKGROUND

Critical illness such as sepsis is a life-threatening syndrome defined as a dysregulated host response to infection and is characterized by patients exhibiting impaired immune response. In the field of diagnosis, a gap still remains in identifying the immune profile of critically ill patients in the intensive care unit (ICU).

METHODS

A new multiplex immune profiling panel (IPP) prototype was assessed for its ability to semiquantify messenger RNA immune-related markers directly from blood, using the FilmArray System, in less than an hour. Samples from 30 healthy volunteers were used for the technical assessment of the IPP tool. Then the tool was clinically assessed using samples from 10 healthy volunteers and 20 septic shock patients stratified using human leukocyte antigen-DR expression on monocytes (mHLA-DR).

RESULTS

The IPP prototype consists of 16 biomarkers that target the immune response. The majority of the assays had a linear expression with different RNA inputs and a coefficient of determination (R2) > 0.8. Results from the IPP pouch were comparable to standard quantitative polymerase chain reaction and the assays were within the limits of agreement in Bland-Altman analysis. Quantification cycle values of the target genes were normalized against reference genes and confirmed to account for the different cell count and technical variability. The clinical assessment of the IPP markers demonstrated various gene modulations that could distinctly differentiate 3 profiles: healthy volunteers, intermediate mHLA-DR septic shock patients, and low mHLA-DR septic shock patients.

CONCLUSIONS

The use of IPP showed great potential for the development of a fully automated, rapid, and easy-to-use immune profiling tool. The IPP tool may be used in the future to stratify critically ill patients in the ICU according to their immune status. Such stratification will enable personalized management of patients and guide treatments to avoid secondary infections and lower mortality.

The clinical outcomes and biomarker features of severe sepsis/septic shock with severe neutropenia: a retrospective cohort study

BACKGROUND

Severe sepsis/septic shock with severe neutropenia often leads to poor prognosis. However, it is unknown if severe neutropenia is associated with different clinical outcomes and biomarker features in severe sepsis/septic patients.

METHODS

This retrospective cohort study enrolled 141 severe sepsis/septic shock patients admitted to intensive care unit of Shanghai Children's Medical Center between January 2015 and November 2019. Patients were followed up for the development of ventilation support, the use of vasoactive drugs, continuous renal replacement therapy (CRRT) procedure, and mortality. Biomarkers that reflect the level of inflammation in severe sepsis/septic shock patients with neutropenia were compared to that in patients without neutropenia.

RESULTS

Of 141 patients enrolled, 54 patients suffered from severe sepsis/septic shock with severe neutropenia. In patients with severe sepsis/septic shock, severe neutropenia as a complication was an independent risk factor for the use of vasoactive drugs (RR 9.796; 95% CI: 3.774, 25.429; P<0.001), but not for ventilation support (RR 0.157; 95% CI: 0.06, 0.414; P<0.001), CRRT procedure (RR 1.032; 95% CI: 0.359, 2.969; P=0.953) or 28-day mortality (RR 1.405; 95% CI: 0.533, 3.708; P=0.492). Severe sepsis/septic patients with severe neutropenia had a higher plasma level of the following biomarkers: c-reaction protein (CRP) (180.5 vs. 121 mg/mL, P<0.001), procalcitonin (PCT) (12.15 vs. 2.7 ng/mL; P=0.005), interleukin (IL)-6 (316.83 vs. 55.77 pg/mL, P<0.001), IL-10 (39.165 vs. 10.09 pg/mL, P<0.001), interferon (IFN)-γ (6.155 vs. 3.71 pg/mL, P=0.016), and the percentage of regulatory T cells (Tregs) (2.7% vs. 2.09%, P=0.003). Based on the receiver operating characteristic curves, IL-10 exhibited high specificity (79.4%) in evaluating the prognosis of septic patients with neutropenia.

CONCLUSIONS

In patients with severe sepsis/septic shock, being complicated with severe neutropenia is associated with higher proportion of using vasoactive drugs, and those patients tend to have higher plasma levels of IL-6, IL-10, IFN-γ and percentage of Treg.

Development of Prediction Models for New Integrated Models and a Bioscore System to Identify Bacterial Infections in Systemic Lupus Erythematosus

Objectives

Distinguishing flares from bacterial infections in systemic lupus erythematosus (SLE) patients remains a challenge. This study aimed to build a model, using multiple blood cells and plasma indicators, to improve the identification of bacterial infections in SLE.

Design

Building PLS-DA/OPLS-DA models and a bioscore system to distinguish bacterial infections from lupus flares in SLE.

Setting

Department of Rheumatology of the Second Hospital of Shanxi Medical University.

Participants

SLE patients with flares (n = 142) or bacterial infections (n = 106) were recruited in this retrospective study.

Outcome

The peripheral blood of these patients was collected by the experimenter to measure the levels of routine examination indicators, immune cells, and cytokines. PLS-DA/OPLS-DA models and a bioscore system were established.

Results

Both PLS-DA (R2Y = 0.953, Q2 = 0.931) and OPLS-DA (R2Y = 0.953, Q2 = 0.942) models could clearly identify bacterial infections in SLE. The white blood cell (WBC), neutrophile granulocyte (NEUT), erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), procalcitonin (PCT), interleukin-6 (IL-6), IL-10, interferon-γ (IFN-γ), and tumor necrosis factor α (TNF-α) levels were significantly higher in bacteria-infected patients, while regulatory T (Treg) cells obviously decreased. A multivariate analysis using the above 10 dichotomized indicators, based on the cut-off value of their respective ROC curve, was established to screen out the independent predictors and calculate their weights to build a bioscore system, which exhibited a strong diagnosis ability (AUC = 0.842, 95% CI 0.794–0.891). The bioscore system showed that 0 and 100% of SLE patients with scores of 0 and 8–10, respectively, were infected with bacteria. The higher the score, the greater the likelihood of bacterial infections in SLE.

Conclusions

The PLS-DA/OPLS-DA models, including the above biomarkers, showed a strong predictive ability for bacterial infections in SLE. Combining WBC, NEUT, CRP, PCT, IL-6, and IFN-γ in a bioscore system may result in faster prediction of bacterial infections in SLE and may guide toward a more appropriate, timely treatment for SLE.

Biomarkers of Platelet Activation and Their Prognostic Value in Patients With Sepsis-Associated Disseminated Intravascular Coagulopathy

Sepsis-associated disseminated intravascular coagulation (DIC) is related to marked hemostatic changes such as transient thrombocytopenia secondary to the endogenous activation and consumption of platelets. This study measured markers of platelet function in 103 adult ICU patients with clinically established sepsis-associated DIC to determine the biomarker association with disease severity. Patients were categorized as having no DIC, nonovert DIC, or overt DIC using the International Society of Thrombosis and Hemostasis scoring system. Plasma levels of CD40L, platelet factor 4 (PF4), platelet-derived microparticles, and microparticle-associated tissue factor were quantified. Markers of platelet activation were significantly elevated in patients with DIC compared to healthy individuals. This increase was independent of platelet count. Levels of PF4 differed based on the severity of DIC and differentiated nonsurvivors and survivors. These findings suggest that the markers of platelet activation in DIC may not be regulated by the number of circulating platelets and may be independent of the factors leading to their consumption.

Optimal combination of early biomarkers for infection and sepsis diagnosis in the emergency department: The BIPS study

OBJECTIVE

To define the best combination of biomarkers for the diagnosis of infection and sepsis in the emergency room.

METHODS

In this prospective study, consecutive patients with a suspicion of infection in the emergency room were included. Eighteen different biomarkers measured in plasma, and twelve biomarkers measured on monocytes, neutrophils, B and T-lymphocytes were studied and the best combinations determined by a gradient tree boosting approach.

RESULTS

Overall, 291 patients were included and analysed, 148 with bacterial infection, and 47 with viral infection. The best biomarker combination which first allowed the diagnosis of bacterial infection, included HLA-DR (human leukocyte antigen DR) on monocytes, MerTk (Myeloid-epithelial-reproductive tyrosine kinase) on neutrophils and plasma metaloproteinase-8 (MMP8) with an area under the curve (AUC) = 0.94 [95% confidence interval (IC95): 0.91;0.97]. Among patients in whom a bacterial infection was excluded, the combination of CD64 expression, and CD24 on neutrophils and CX3CR1 on monocytes ended to an AUC = 0.98 [0.96;1] to define those with a viral infection.

CONCLUSION

In a convenient cohort of patients admitted with a suspicion of infection, two different combinations of plasma and cell surface biomarkers were performant to identify bacterial and viral infection.

Circulating Exosomes Are Strongly Involved in SARS-CoV-2 Infection

Knowledge of the host response to the novel coronavirus SARS-CoV-2 remains limited, hindering the understanding of COVID-19 pathogenesis and the development of therapeutic strategies. During the course of a viral infection, host cells release exosomes and other extracellular vesicles carrying viral and host components that can modulate the immune response. The present study used a shotgun proteomic approach to map the host circulating exosomes’ response to SARS-CoV-2 infection. We investigated how SARS-CoV-2 infection modulates exosome content, exosomes’ involvement in disease progression, and the potential use of plasma exosomes as biomarkers of disease severity. A proteomic analysis of patient-derived exosomes identified several molecules involved in the immune response, inflammation, and activation of the coagulation and complement pathways, which are the main mechanisms of COVID-19–associated tissue damage and multiple organ dysfunctions. In addition, several potential biomarkers—such as fibrinogen, fibronectin, complement C1r subcomponent and serum amyloid P-component—were shown to have a diagnostic feature presenting an area under the curve (AUC) of almost 1. Proteins correlating with disease severity were also detected. Moreover, for the first time, we identified the presence of SARS-CoV-2 RNA in the exosomal cargo, which suggests that the virus might use the endocytosis route to spread infection. Our findings indicate circulating exosomes’ significant contribution to several processes—such as inflammation, coagulation, and immunomodulation—during SARS-CoV-2 infection. The study’s data are available via ProteomeXchange with the identifier PXD021144.

Association of Plasma Levels of FAS Ligand with Severity and Outcome of Sepsis

INTRODUCTION

Levels of the apoptosis regulator Fas ligand (FasL) are associated with severity of sepsis, but its association with the mortality of sepsis and necroptosis, a regulated cell death mechanism, is not yet clear. We aimed to assess the association of FasL level with outcomes of sepsis and receptor interacting protein kinase-3 (RIPK3), an essential necroptosis mediator, for determining the relationship between FasL and necroptosis.

METHODS

Plasma FasL and RIPK3 levels were measured by ELISA from prospectively enrolled critically-ill adult patients. The best cut-off level of FasL for 28-day mortality prediction was determined by Youden's index. The association between plasma levels of FasL and RIPK3 was assessed by a linear regression method.

RESULTS

Among 188 patients, 58 (30.9%) were diagnosed with sepsis and 84 (44.7%) with septic shock, respectively. Plasma levels of FasL increased in the group order of control, sepsis, and septic shock groups (P for trend < 0.001). For 142 patients with sepsis, organ dysfunction and septic shock were more prevalent in the group with plasma FasL levels that were higher than the best cut-off level. A significant difference in mortality between high and low FasL patients was observed up to 90 days (Log-rank P = 0.013). FasL levels did not significantly change over day 3 and day 7. FasL levels were not correlated with those of RIPK3.

CONCLUSIONS

The plasma level of FasL was associated with severity of sepsis and was predictive of mortality. However, it was not correlated with RIPK3 level.

Prognostic Accuracy of VqSOFA for Predicting 28-day Mortality in Patients with Suspected Sepsis in the Emergency Department

BACKGROUND

Sepsis screening in the emergency department (ED) is challenging. The quick Sequential Organ Failure Assessment (qSOFA) score had poor accuracy for predicting mortality in both the intensive care unit and ED. High lactate levels were associated with an increased mortality. However, a previous study using lactate levels in combination with the qSOFA score did not observe a meaningful improvement in predictive accuracy. This study assessed the prognostic accuracy of venous lactate levels plus the qSOFA (VqSOFA) score for predicting 28-day mortality.

METHODS

Patients who visited the Ramathibodi ED with suspected sepsis were enrolled. The VqSOFA, qSOFA, and Sequential Organ Failure Assessment (SOFA) scores were calculated using the initial vital signs and laboratory values. Prognostic accuracy was measured using the area under the receiver operating characteristic (AUROC) curve of the VqSOFA score and Sepsis-3 criteria for predicting 28-day mortality.

RESULTS

In total, 1,139 patients were enrolled, 118 of whom died within 28 days of admission. The AUROCs of the VqSOFA, qSOFA, and SOFA scores were 0.851 (95% CI 0.813-0.889), 0.813 (95% CI 0.772-0.854), and 0.728 (95% CI 0.671-0.784), respectively. Using VqSOFA score ≥ 3 as the cutoff, the sensitivity, specificity, and positive likelihood ratio were 74.6%, 82.5%, and 4.25%, respectively. VqSOFA ≥ 3 was linked to a low probability of 28-day survival and higher odds of vasopressor and ventilator use within 24 h.

CONCLUSIONS

VqSOFA was more predictive of 28-day mortality and vasopressor and mechanical ventilator use than the qSOFA and SOFA scores.

Early Procalcitonin Assessment in the Emergency Department in Patients with Intra-Abdominal Infection: An Excess or a Need?

Background: Intra-abdominal infection (IAI) is a wide range of intra-abdominal disease. Management involves empirical therapy and source control. Procalcitonin (PCT) has been suggested to assist in defining individual infection status and delivering individualized therapy. The aim of this study was to investigate the effects on patient outcomes of an early procalcitonin (PCT) assessment (in the emergency department [ED]) in patients with IAI. Methods: This was a retrospective, mono-centric study evaluating consecutive patients admitted to the ED from 2015 to 2019 with diagnosis of IAI. According to whether there had been PCT determination in the ED, patients were divided into no ePCT determination (no-ePCT) and early PCT determination in the ED (ePCT). The primary endpoint was the intra-hospital mortality rate. Secondary endpoints were occurrence of major complications and length of hospital stay (LOS). The propensity score match (PSM) was generated using a logistic regression model on the baseline covariates considered to be potentially influencing the decision to determine PCT in the ED and confounding factors identified as significant at a preliminary statistical analysis with respect to in-hospital death. Results: A series of 3,429 patients were included. The ePCT group consisted to 768 (22.4%), whereas the no-ePCT group contained 2,661 patients (77.6%). When the PSM was matched to the two groups, no significant difference was observed. Considering patients with uncomplicated infections, the PCT determination was associated with a higher mortality rate. We found no significant differences regarding outcomes with the exception of LOS, which was slightly longer in the ePCT group. However, we observed a tendency toward a minor difference in the number of complications in the ePCT group, in particular a reduced rate of progression to sepsis. Conclusion: Early PCT determination could be irrelevant in IAIs. The PCT value may be cost-effective and possibly improve the prognosis in cIAIs. Further research is needed to understand the optimal use of PCT, including in combination with other emerging diagnostic tests.

Surface TREM-1 as a Prognostic Biomarker in Pediatric Sepsis

OBJECTIVES

To investigate the association between the triggering receptor expressed on myeloid cells-1 (TREM-1) levels and prognosis in septic children.

METHODS

Patients admitted to pediatric intensive care units (PICU) of three tertiary centers were included in this prospective observational study. Serum samples were taken at admission from patients who were hospitalized with sepsis.

RESULTS

Of the 87 patients included, 34 (39.1%) had severe sepsis and 53 (60.9%) had septic shock. The median age was 2 y (2 mo to 16 y). TREM-1 values were found to be significantly higher in septic shock patients 129 pg/ml (min 9.85- max 494.90) compared to severe sepsis 105 pg/ml (min 8.21- max 289.17) (p = 0.048). Despite higher TREM-1 levels been measured in non-survivors compared to survivors, it was not statistically significant [168.98 pg/ml (min 9.85- max 494.90) vs. 110.79 pg/ml (min 8.21- max 408.90), (p = 0.075)].

CONCLUSIONS

Admission TREM-1 levels were higher in septic shock compared to severe sepsis patients. There was no association between mortality and TREM-1 levels in sepsis. TREM-1 measurements should be used carefully in pediatric sepsis prognosis.

Integrating infection and sepsis management through holistic early warning systems and heuristic approaches: a concept proposal

This is a first attempt to integrate the three pillars of infection management: the infection prevention and control (IPC), and surveillance (IPCS), antimicrobial stewardship (AMS), and rapid identification and management of sepsis (RIMS). The new 'Sepsis-3' definition extrapolates the diagnosis of sepsis from our previously slightly naïve concept of a stepwise evolving pattern. In doing so, however, we have placed the transition from infection toward sepsis in the domain of uncertainty and time-dependency. This now demands that clinical judgment be used in the risk stratification of patients with infection, and that pragmatic local solutions be used to prompt clinicians to evaluate formally for sepsis. We feel it is necessary to stimulate the development of a new generation of concepts and models aiming at embracing uncertainty. We see the opportunity for a heuristic approach focusing on the relevant clinical predictors at hand allowing to navigate the uncertainty of infection diagnosis under time constraints. The diverse and situated clinical approaches eventually emerging need to focus on the understanding of infection as the unbalanced interactions of host, pathogen, and environment. In order extend such approach throughout the patient journey we propose a holistic early warning system underpinned by the risk-based categories of hazards and vulnerabilities iteratively fostered by the information gathered by the infection prevention control and surveillance, clinical microbiology, and clinical chemistry services.

Associations between urinary 3-indoxyl sulfate, a gut microbiome-derived biomarker, and patient outcomes after intensive care unit admission

PURPOSE

3-indoxyl sulfate (3-IS) is an indole metabolism byproduct produced by commensal gut bacteria and excreted in the urine; low urinary 3-IS has been associated with increased mortality in bone marrow transplant recipients. This study investigated urinary 3-IS and patient outcomes in the ICU.

MATERIALS AND METHODS

Prospective study that collected urine samples, rectal swabs, and clinical data on 78 adult ICU patients at admission and again 72 h later. Urine was analyzed for 3-IS by mass spectrometry.

RESULTS

Median urinary 3-IS levels were 17.1 μmol/mmol creatinine (IQR 9.5 to 26.2) at admission and 15.6 (IQR 4.2 to 30.7) 72 h later. 22% of patients had low 3-IS (≤6.9 μmol/mmol) on ICU admission and 28% after 72 h. Low 3-IS at 72 h was associated with fewer ICU-free days (22.5 low versus 26 high, p = 0.03) and with death during one year of follow-up (36% low versus 9% high 3-IS, p < 0.01); there was no detectable difference in 30-day mortality (18% low versus 5% high, p = 0.07).

CONCLUSIONS

Low urinary 3-IS level 72 h after ICU admission was associated with fewer ICU-free days and with increased one-year but not 30-day mortality. Further studies should investigate urinary 3-IS as an ICU biomarker.

Should serial monitoring of procalcitonin be done routinely in critically ill patients of ICU: A systematic review and meta-analysis

Sepsis is a life-threatening condition with dysregulated host response to infection. It is a major determinant of mortality in the intensive care unit (ICU). Procalcitonin (PCT) is widely investigated for prognosis in patients with sepsis. Most of the studies have cited that elevated PCT concentrations and PCT non-clearance are associated with poor outcomes in patients with sepsis and some studies have cited as having no additional benefit. Most of the studies have evaluated single PCT measurement and correlated with prognosis and outcome in septic patients. Limited literature is there about serial PCT levels and its impact on the outcome of patients with sepsis. We searched literature through PubMed, Embase, Web of Knowledge, and the Cochrane Library from 2007 to 2017 and present a systematic review and meta-analysis of studies evaluating the utility of serial measurement of PCT for prognosis in critically ill patients. Articles that assessed PCT non-clearance as a marker of mortality data were included. The primary objective of this meta-analysis was to pool the results of all the available studies on serial PCT non-clearance as a mortality predictor and formulate overall area under receiver operating curve (AUROC). To find out the overall proportion of mortality in PCT non-clearance was our secondary objective. To detect the mortality using PCT non-clearance, ROC curve analysis was done. Area under curve (AUC) of the studies was varying between 0.52 and 0.86. Overall AUC was observed 0.711 (95% confidence interval (CI): 0.662–0.760) under fixed effect model and 0.708 (95% CI: 0.648–0.769) under random effect model. There was moderate variation among the studies, i.e., I² 50.80% (95% CI: 0.00–80.42%). The overall proportion of mortality was 37.54% with much heterogeneity (I² 88.24%) among the studies. PCT non-clearance is a fair predictor of mortality. Further studies are needed to define optimal cut off point for PCT non-clearance in ICU patients with sepsis.

Vibrational spectroscopic analysis of blood for diagnosis of infections and sepsis: a review of requirements for a rapid diagnostic test

Infections and sepsis represent a growing global burden. There is a widespread clinical need for a rapid, high-throughput and sensitive technique for the diagnosis of infections and detection of invading pathogens and the presence of sepsis. Current diagnostic methods primarily consist of laboratory-based haematology, biochemistry and microbiology that are time consuming, labour- and resource-intensive, and prone to both false positive and false negative results. Current methods are insufficient for the increasing demands on healthcare systems, causing delays in diagnosis and initiation of treatment, due to the intrinsic time delay in sample preparation, measurement, and analysis. Vibrational spectroscopic techniques can overcome these limitations by providing a rapid, label-free and low-cost method for blood analysis, with limited sample preparation required, potentially revolutionising clinical diagnostics by producing actionable results that enable early diagnosis, leading to improved patient outcomes. This review will discuss the challenges associated with the diagnosis of infections and sepsis, primarily within the UK healthcare system. We will consider the clinical potential of spectroscopic point-of-care technologies to enable blood analysis in the primary-care setting.

Advances in sepsis diagnosis and management: a paradigm shift towards nanotechnology

Sepsis, a dysregulated immune response due to life-threatening organ dysfunction, caused by drug-resistant pathogens, is a major global health threat contributing to high disease burden. Clinical outcomes in sepsis depend on timely diagnosis and appropriate early therapeutic intervention. There is a growing interest in the evaluation of nanotechnology-based solutions for sepsis management due to the inherent and unique properties of these nano-sized systems. This review presents recent advancements in nanotechnology-based solutions for sepsis diagnosis and management. Development of nanosensors based on electrochemical, immunological or magnetic principals provide highly sensitive, selective and rapid detection of sepsis biomarkers such as procalcitonin and C-reactive protein and are reviewed extensively. Nanoparticle-based drug delivery of antibiotics in sepsis models have shown promising results in combating drug resistance. Surface functionalization with antimicrobial peptides further enhances efficacy by targeting pathogens or specific microenvironments. Various strategies in nanoformulations have demonstrated the ability to deliver antibiotics and anti-inflammatory agents, simultaneously, have been reviewed. The critical role of nanoformulations of other adjuvant therapies including antioxidant, antitoxins and extracorporeal blood purification in sepsis management are also highlighted. Nanodiagnostics and nanotherapeutics in sepsis have enormous potential and provide new perspectives in sepsis management, supported by promising future biomedical applications included in the review.

Changes in Sepsis Biomarkers after Immunosuppressant Administration in Transplant Patients

Sepsis biomarkers change continuously during the postoperative period. We aimed to demonstrate the influence of immunosuppressants after transplantation (Tx) on presepsin, procalcitonin, CRP, white blood cells, and IL-6. A group of 140 patients after major surgery (86 non-Tx, 54 Tx) without any signs of sepsis or infectious complications was followed for 7 days. The changes in biomarkers were analyzed with respect to the type of surgery, organ, and induction immunosuppressant used (antithymocyte globulin, corticosteroids, or basiliximab/rituximab). Concentrations (95th percentiles) of presepsin and procalcitonin were higher in the Tx group (presepsin: Tx < 2380 vs. non‐Tx < 1368 ng/L, p < 0.05; procalcitonin: <28.0 vs. 3.49 μg/L, p < 0.05). In contrast, CRP and IL-6 were lower in the Tx group (CRP: Tx < 84.2 vs. non‐Tx < 229 mg/L, p < 0.05; IL-6: <71.2 vs. 317 ng/L, p < 0.05). Decreases in CRP and IL-6 were found for all immunosuppressants, and procalcitonin was increased after antithymocyte globulin and corticosteroids. Negligible changes were found for white blood cells. Different responses of presepsin, procalcitonin, CRP, and IL-6 were therefore found in patients without any infectious complications after major surgery or transplantation. Immunosuppression decreased significantly IL-6 and CRP in comparison to non-Tx patients, while procalcitonin was increased after corticosteroids and antithymocyte globulin only. Cautious interpretation of sepsis biomarkers is needed in the early posttransplant period. This work was conducted as a noninterventional (nonregistered) study.

Distinct cell death markers identified in critical care patient survivors diagnosed with sepsis

Sepsis is an abnormal immune response to infection characterized by an overwhelming systemic inflammation and cell death. Non-apoptotic cell death pertaining to pyroptosis, necroptosis and autophagy contribute to sepsis pathogenesis apart from classical apoptotic cell death. The objective of the current study is to investigate the presence of molecular markers of relevance to apoptotic and non-apoptotic cell death in control healthy subjects and septic patient survivors. Sepsis survivors (N = 24) and healthy human volunteers (N = 16) [40 total subjects] were recruited into the study. Clinical intervention included antibiotic treatment regimen administered to patients upon clinical diagnosis of sepsis followed by blood draw 18-24 hr post-antibiotic dose. Serum samples analyzed by enzyme-linked immunosorbent assay (ELISA) and peripheral blood mononuclear cells (PBMCs) by flow cytometry analysis for identification of cell death markers. Cell death markers analyzed by ELISA and flow cytometry included caspase-1, caspase-3, MLKL, RIPK3, p62 and LC3B. Serum and peripheral blood mononuclear cells (PBMCs) of septic survivors and healthy controls analyzed for the presence of distinct cell death markers. Markers of relevance to apoptosis (caspase-3), pyroptosis (caspase-1), necroptosis (MLKL) and autophagy (p62 and LC3B) were compared between septic survivors and healthy controls. ELISA analysis suggested significant alterations in the serum levels of non-apoptotic cell death markers, caspase-1 and p62/SQSTM1, in septic survivors compared to healthy controls (p < 0.05). There was no significant difference in the serum levels of caspase-3 and MLKL between septic survivors and healthy control subjects (p> 0.05). Intracellular caspase-1 levels did not show any significant alterations between septic survivors and healthy control subjects (p > 0.05). Flow cytometry analysis suggested significant increase in the intracellular expression of caspase-3, MLKL and its associated kinase RIPK3, and p62/SQSTM1 (p < 0.05) in sepsis patient survivors when compared to healthy human subjects. The current observational study identified significantly elevated levels of non-apoptotic cell death markers in sepsis patients compared to healthy controls. Noteworthy observation is the significant modulation of non-apoptotic cell death markers in serum samples derived from septic survivors post-antibiotic administration compared to healthy control subjects. Preliminary results serve as a basis for further mechanistic investigations to elucidate the role of distinct cell death markers in the prediction of clinical outcomes in sepsis.

Nanotools for Sepsis Diagnosis and Treatment

Sepsis is one of the leading causes of death worldwide with high mortality rates and a pathological complexity hindering early and accurate diagnosis. Today, laboratory culture tests are the epitome of pathogen recognition in sepsis. However, their consistency remains an issue of controversy with false negative results often observed. Clinically used blood markers, C reactive protein (CRP) and procalcitonin (PCT) are indicators of an acute-phase response and thus lack specificity, offering limited diagnostic efficacy. In addition to poor diagnosis, inefficient drug delivery and the increasing prevalence of antibiotic-resistant microorganisms constitute significant barriers in antibiotic stewardship and impede effective therapy. These challenges have prompted the exploration for alternative strategies that pursue accurate diagnosis and effective treatment. Nanomaterials are examined for both diagnostic and therapeutic purposes in sepsis. The nanoparticle (NP)-enabled capture of sepsis causative agents and/or sepsis biomarkers in biofluids can revolutionize sepsis diagnosis. From the therapeutic point of view, currently existing nanoscale drug delivery systems have proven to be excellent allies in targeted therapy, while many other nanotherapeutic applications are envisioned. Herein, the most relevant applications of nanomedicine for the diagnosis, prognosis, and treatment of sepsis is reviewed, providing a critical assessment of their potentiality for clinical translation.

Sepsis Biomarkers

Biomarkers have been used in sepsis to assist with the diagnosis of disease as well as determining the severity of disease, that is, prognosis. These biomarkers are based on the presence of discrete molecules within the blood. Unfortunately, in 2020, a single biomarker does not have sufficient sensitivity and specificity to definitively rule in or rule out sepsis. Biomarkers have shown better performance in animal models of disease.

Colonization of Germ-Free Piglets with Mucinolytic and Non-Mucinolytic Bifidobacterium boum Strains Isolated from the Intestine of Wild Boar and Their Interference with Salmonella Typhimurium

Non-typhoidal Salmonella serovars are worldwide spread foodborne pathogens that cause diarrhea in humans and animals. Colonization of gnotobiotic piglet intestine with porcine indigenous mucinolytic Bifidobacterium boum RP36 strain and non-mucinolytic strain RP37 and their interference with Salmonella Typhimurium infection were compared. Bacterial interferences and impact on the host were evaluated by clinical signs of salmonellosis, bacterial translocation, goblet cell count, mRNA expression of mucin 2, villin, claudin-1, claudin-2, and occludin in the ileum and colon, and plasmatic levels of inflammatory cytokines IL-8, TNF-α, and IL-10. Both bifidobacterial strains colonized the intestine comparably. Neither RP36 nor RP37 B. boum strains effectively suppressed signs of salmonellosis. Both B. boum strains suppressed the growth of S. Typhimurium in the ileum and colon. The mucinolytic RP36 strain increased the translocation of S. Typhimurium into the blood, liver, and spleen.

Prognostic value of plasma pentraxin 3 levels in patients with septic shock admitted to intensive care

Objective

To evaluate the usefulness of a new marker, pentraxin, as a prognostic marker in septic shock patients.

Materials and methods

Single-centre prospective observational study that included all consecutive patients 18 years or older who were admitted to the intensive care unit (ICU) with septic shock. Serum levels of procalcitonin (PCT), C-reactive protein (CRP) and pentraxin (PTX3) were measured on ICU admission.

Results

Seventy-five septic shock patients were included in the study. The best predictors of in-hospital mortality were the severity scores: SAPS II (AUC = 0.81), SOFA (AUC = 0.79) and APACHE II (AUC = 0.73). The ROC curve for PTX3 (ng/mL) yielded an AUC of 0.70, higher than the AUC for PCT (0.43) and CRP (0.48), but lower than lactate (0.79). Adding PTX3 to the logistic model increased the predictive capacity in relation to SAPS II, SOFA and APACHE II for in-hospital mortality (AUC 0.814, 0.795, and 0.741, respectively). In crude regression models, significant associations were found between in-hospital mortality and PTX3. This positive association increased after adjusting for age, sex and immunosuppression: adjusted OR T3 for PTX3 = 7.83, 95% CI 1.35–45.49, linear P trend = 0.024.

Conclusion

Our results support the prognostic value of a single determination of plasma PTX3 as a predictor of hospital mortality in septic shock patients.