Current Evidence and Limitation of Biomarkers for Detecting Sepsis and Systemic Infection

Case Report: A rare case of community-acquired Roseomonas mucosa sepsis that presented with persistently normal host-response biomarkers

Community-acquired Roseomonas mucosa sepsis can lead to significant morbidity and mortality if not diagnosed promptly. We report a case of a 59-year-old woman with community-acquired Roseomonas mucosa sepsis who presented with persistent fever progressing to septic shock, despite repeatedly negative host-response biomarker results. Initial metagenomic analysis of peripheral blood suggested Pseudomonas aeruginosa infection. However, a peripheral blood culture identified Roseomonas mucosa as the causative pathogen. She was cured after switching to meropenem according to blood cultures and antimicrobial susceptibility testing.

Prognostic value of C-reactive protein levels in pulmonary infections: A systematic review and meta-analysis

BACKGROUND

C-reactive rotein (CRP) has been extensively studied as a biomarker that can predict mortality in patients with acute lung disease and our study aimed to elucidate the prognostic value of CRP levels for mortality in patients with various airway diseases, accounting for these differences and potential confounding factors accounts.

METHODS

An extensive literature search was conducted in several databases including PubMed, Embase, Web of Science, Scopus, and ProQuest to ensure the inclusion of up-to-date evidence from studies published between January 2019 and December 2024. Both fixed-effects and random-effects models were used to calculate pooled mean hazard ratios (HR) and odds ratios (OR) for mortality.

RESULTS

For mortality, the fixed effects model revealed a HR of 1.0065 (95% CI: 1.0054-1.0075, P < .0001), indicating a slightly increased risk of death associated with higher CRP levels. However, the random effects model, considering study heterogeneity, suggested an HR of 1.0488 (95% CI: 0.9978-1.1024, P = .0608), with significant heterogeneity (Q = 135.31, P < .0001). The OR analysis under the random effects model showed a more substantial increase in mortality risk with an OR of 1.2033 (95% CI: 1.0635-1.3614, P = .0033). Regarding ICU admissions and ventilation needs, substantial heterogeneity was also observed. The analysis did not find a statistically significant association between elevated CRP levels and ICU admission (OR = 1.1108, 95% CI: 0.9604-1.2847, P = .1568) or the necessity for ventilation (OR = 1.8981, 95% CI: 0.9651-3.7331, P = .0633), although both indicated trends towards increased risk.

CONCLUSION

CRP levels show a potential yet inconsistent association with mortality risk in patients with pulmonary infections. While elevated CRP levels suggest an increased risk of mortality, the results should be interpreted cautiously due to potential overestimation of the effect and the presence of publication bias.

Advancing risk factor identification for pediatric lobar pneumonia: the promise of machine learning technologies

Background

Community-acquired pneumonia (CAP) is a prevalent pediatric condition, and lobar pneumonia (LP) is considered a severe subtype. Early identification of LP is crucial for appropriate management. This study aimed to develop and compare machine learning models to predict LP in children with CAP.

Methods

A total of 25 clinical and laboratory variables were collected. Missing data (<2%) were imputed, and the dataset was split into training (60%) and validation (40%) sets. Univariable logistic regression and Boruta feature selection were used to identify significant predictors. Four machine learning algorithms-Logistic Regression (LR), Support Vector Machine (SVM), Extreme Gradient Boosting (XGBoost), and Decision Tree (DT)-were compared using area under the curve (AUC), balanced accuracy, sensitivity, specificity, and F1 score. SHAP analysis was performed to interpret the best-performing model.

Results

A total of 278 patients with CAP were included in this study, of whom 65 were diagnosed with LP. The XGBoost model demonstrated the best performance with an AUC of 0.880 (95% CI: 0.807-0.934) in the training set and 0.746 (95% CI: 0.664-0.843) in the validation set. SHAP analysis identified age, CRP, CD64 index, lymphocyte percentage, and ALB as the top five predictive factors.

Conclusion

The XGBoost model showed superior performance in predicting LP in children with CAP. The model enabled early diagnosis and risk assessment of LP, thereby facilitating appropriate clinical decision-making.

ED Nurse-Led Code Sepsis to Reduce Time to Antibiotics

BACKGROUND

Delays in sepsis recognition contribute to delays in antibiotic administration, which lead to increased morbidity and mortality in patients with sepsis. Our objective was to create an Emergency Department (ED) Code Sepsis Nurse-led team to reduce the time to antibiotics and mortality in patients with sepsis.

METHODS

This initiative was implemented at a community hospital in Southern California in response to previous undesirable sepsis outcomes. In fiscal year 2021, the ED Sepsis Nursing Team was launched with the goal of improving sepsis-related outcomes. The following interventions were implemented: First, a group of dedicated Sepsis Nurses with training specific to sepsis recognition was created, and an electronic ED-sepsis screening tool was developed and implemented. Next, the dedicated sepsis nurses designed and educated to a "Code Sepsis" activation process. The code triggered a multidisciplinary response and implementation of standing orders for blood cultures, lactate, complete blood count, complete metabolic panel, and chest x-ray or urinalysis if indicated. Finally, the Sepsis Team Registered Nurse (RN) Captain led house-wide monthly Sepsis Task Force meetings to improve unit-level engagement and to allow the team to have ownership over sharing wins and losses.

RESULTS

By Quarter 4 (Q4) of Fiscal Year 2021, door-to-antibiotic time for sepsis patients dropped from 196.7 min (Q1) to 144.7 (Q4). Additionally, mortality dropped below the health system average (10.4% vs. 13.5%), and Fiscal Year 2021 surpassed the readmissions benchmark of <1.0 at a rate of 0.5.

CONCLUSION

An RN-led, interprofessional response to accepted sepsis identification criteria enhanced staff and physician engagement and improved sepsis outcomes for patient mortality and hospital reporting outcomes. The process was adopted with very few obstacles that were easily overcome as the understanding of the role and its significance was realized.

Diagnostic Value of Endotoxin Activity for Acute Postoperative Complications: A Study in Major Abdominal Surgery Patients

Background/Objectives: Endotoxin, a component of lipopolysaccharide (LPS) from bacteria, disrupts the immune system, potentially leading to multiorgan failure. Unlike previous studies, we enrolled patients with mild clinical conditions after major abdominal surgery and assessed the predictive value of endotoxin activity (EA) levels for acute complications which occur within 7 days postoperatively. Also, the differential diagnostic value of EA was assessed in a subgroup of patients with abnormal liver function during the immediate postoperative period. Methods: Patients admitted to the surgical ICU of our institution following elective abdominal surgery were enrolled. Participants were classified into low/high postoperative EA groups based on EA cutoff values for predicting complications. Additionally, participants were categorized based on liver function assessed at ICU admission using total bilirubin (TB) levels. Abnormal liver function was defined as a TB level > 1.2 mg/dL. Results: 86 patients were analyzed. The EA cutoff for postoperative complications was 0.485, with 49 patients (57%) categorized in the low EA group (EA levels < 0.485) and 37 patients (43%) in the high EA group (EA levels ≥ 0.485). The high EA group experienced statistically worse outcomes, including longer ICU stays and higher mortality rates. Logistic regression analysis confirmed that EA levels and SOFA scores were significant predictors of postoperative complications. For patients with elevated TB, the EA cutoff value for postoperative complications was 0.515, which is higher than those obtained for the total patient cohort. Conclusions: EA level is a viable surveillance tool for detecting postoperative complications in the acute period among ICU patients undergoing major abdominal surgery, and must be interpreted carefully considering the patient's liver function.

Crossing Age Boundaries: The Unifying Potential of Presepsin in Sepsis Diagnosis Across Diverse Age Groups

Sepsis is a pervasive condition that affects individuals of all ages, with significant social and economic consequences. The early diagnosis of sepsis is fundamental for establishing appropriate treatment and is based on warning scores and clinical characteristics, with positive microbiological cultures being the gold standard. Research has yet to identify a single biomarker to meet this diagnostic demand. Presepsin is a molecule that has the potential as a biomarker for diagnosing sepsis. In this paper, we present a narrative review of the diagnostic and prognostic performance of presepsin in different age groups. Given its particularities, it is identified that presepsin is a potential biomarker for sepsis at all stages of life.

ANXA3 as a novel biomarker for sepsis diagnosis: Evidence from integrative WGCNA analysis

Sepsis is a dysregulated immune response to infection that comes with multiple organ dysfunction and high mortality. The management of sepsis relies heavily on early recognition and diagnosis, but current diagnostic methods have limitations in timeliness, sensitivity, and discriminability. This study aims to discover novel biomarkers for sepsis diagnosis. Four datasets from different regions were analyzed using weighted gene co-expression network analysis (WGCNA), and genes with high Gene Significance values across these datasets were overlapped. Finally, two genes, CD177 and ANXA3, were identified. ANXA3 was validated as a potential sepsis biomarker by checking multiple datasets and Receiver Operating Characteristic (ROC) Curve Analysis. Of note, ANXA3 could distinguish not only between adult and child sepsis patients and healthy controls, but also between septic shock and cardiogenic shock. Moreover, a murine sepsis model was established and the results showed that the transcription of ANXA3 in peripheral blood of septic mice was significantly higher than that of healthy controls, while Escherichia coli infection alone did not significantly increase the transcription level of this gene. Subsequent studies of sepsis in mice revealed that the predictive effect of Anxa3 on sepsis could be observed as early as 6 h post-modeling. Interestingly, ANXA3 expression was predominantly up-regulated in myeloid cells, up-regulated in spleen, down-regulated in lung, and not detected in liver after sepsis modeling. Taken together, this study provides a way for the discovery of biomarkers and finds that ANXA3 may be a novel diagnostic biomarker for sepsis.

Sepsis Biomarkers: Advancements and Clinical Applications-A Narrative Review

Sepsis is now defined as a life-threatening syndrome of organ dysfunction triggered by a dysregulated host response to infection, posing significant challenges in critical care. The main objective of this review is to evaluate the potential of emerging biomarkers for early diagnosis and accurate prognosis in sepsis management, which are pivotal for enhancing patient outcomes. Despite advances in supportive care, traditional biomarkers like C-reactive protein and procalcitonin have limitations, and recent studies have identified novel biomarkers with increased sensitivity and specificity, including circular RNAs, HOXA distal transcript antisense RNA, microRNA-486-5p, protein C, triiodothyronine, and prokineticin 2. These emerging biomarkers hold promising potential for the early detection and prognostication of sepsis. They play a crucial role not only in diagnosis but also in guiding antibiotic therapy and evaluating treatment effectiveness. The introduction of point-of-care testing technologies has brought about a paradigm shift in biomarker application, enabling swift and real-time patient evaluation. Despite these advancements, challenges persist, notably concerning biomarker variability and the lack of standardized thresholds. This review summarizes the latest advancements in sepsis biomarker research, spotlighting the progress and clinical implications. It emphasizes the significance of multi-biomarker strategies and the feasibility of personalized medicine in sepsis management. Further verification of biomarkers on a large scale and their integration into clinical practice are advocated to maximize their efficacy in future sepsis treatment.

Can We Improve Mortality Prediction in Patients with Sepsis in the Emergency Department?

Background and Objectives: Sepsis represents a global health challenge and requires advanced diagnostic and prognostic approaches due to its elevated rate of morbidity and fatality. Our study aimed to assess the value of a novel set of six biomarkers combined with severity scores in predicting 28 day mortality among patients presenting with sepsis in the Emergency Department (ED). Materials and Methods: This single-center, observational, prospective cohort included sixty-seven consecutive patients with septic shock and sepsis enrolled from November 2020 to December 2022, categorized into survival and non-survival groups based on outcomes. The following were assessed: procalcitonin (PCT), soluble Triggering Receptor Expressed on Myeloid Cells-1 (sTREM-1), the soluble form of the urokinase plasminogen activator receptor (suPAR), high-sensitivity C-reactive protein (hs-CRP), interleukin-6 (IL-6), and azurocidin 1 (AZU1), alongside clinical scores such as the Quick Sequential Organ Failure Assessment (qSOFA), Systemic Inflammatory Response Syndrome (SIRS), the Sequential Organ Failure Assessment (SOFA), the Acute Physiology and Chronic Health Evaluation II (APACHE II), the Simplified Acute Physiology Score II and III (SAPS II/III), the National Early Warning Score (NEWS), Mortality in Emergency Department Sepsis (MEDS), the Charlson Comorbidity Index (CCI), and the Glasgow Coma Scale (GCS). The ability of each biomarker and clinical score and their combinations to predict 28 day mortality were evaluated. Results: The overall mortality was 49.25%. Mechanical ventilation was associated with a higher mortality rate. The levels of IL-6 were significantly higher in the non-survival group and had higher AUC values compared to the other biomarkers. The GCS, SOFA, APACHEII, and SAPS II/III showed superior predictive ability. Combining IL-6 with suPAR, AZU1, and clinical scores SOFA, APACHE II, and SAPS II enhanced prediction accuracy compared with individual biomarkers. Conclusion: In our study, IL-6 and SAPS II/III were the most accurate predictors of 28 day mortality for sepsis patients in the ED.

Biomarkers in sepsis

Sepsis is a life-threatening condition characterized by dysregulated host response to infection leading to organ dysfunction. Despite advances in understanding its pathology, sepsis remains a global health concern and remains a major contributor to mortality. Timely identification is crucial for improving clinical outcomes, as delayed treatment significantly impacts survival. Accordingly, biomarkers play a pivotal role in diagnosis, risk stratification, and management. This review comprehensively discusses various biomarkers in sepsis and their potential application in antimicrobial stewardship and risk assessment. Biomarkers such as white blood cell count, neutrophil to lymphocyte ratio, erythrocyte sedimentation rate, C-reactive protein, interleukin-6, presepsin, and procalcitonin have been extensively studied for their diagnostic and prognostic value as well as in guiding antimicrobial therapy. Furthermore, this review explores the role of biomarkers in risk stratification, emphasizing the importance of identifying high-risk patients who may benefit from specific therapeutic interventions. Moreover, the review discusses the emerging field of transcriptional diagnostics and metagenomic sequencing. Advances in sequencing have enabled the identification of host response signatures and microbial genomes, offering insight into disease pathology and aiding species identification. In conclusion, this review provides a comprehensive overview of the current understanding and future directions of biomarker-based approaches in sepsis diagnosis, management, and personalized therapy.

The Effect of Cytokine Adsorption on Leukocyte and Platelet Activation after Extracorporeal Cardiopulmonary Resuscitation

BACKGROUND

 Post-cardiac arrest syndrome (PCAS) is a frequent complication following successful cardiopulmonary resuscitation and correlates with poor outcome. PCAS is characterized by an excessive inflammatory response to whole-body ischemia and reperfusion. Cytokine adsorption was suggested as an adjunctive treatment option for the removal of cytokines from the patients' blood to restore the physiological equilibrium of pro- and anti-inflammatory activity and thus mitigate hemodynamic instability and end-organ complications.

MATERIAL AND METHODS

 To better understand the cellular effects of cytokine adsorption in patients receiving extracorporeal cardiopulmonary resuscitation (ECPR) after in- and out-of-hospital cardiac arrest, we compared the activation status of neutrophils, monocytes, and platelets as well as the formation of platelet-leukocyte complexes in intravenous whole blood samples from an exploratory subgroup (n = 24) from the randomized CYTER study.

RESULT

 At 48 hours after initiation of ECPR, flow cytometry analyses did neither reveal significant differences in neutrophil (CD11b, CD66b, L-selectin, and PSGL-1) and monocyte (CD11b, L-selectin, and PSGL-1) surface molecule expression nor in circulating platelet-monocyte complexes between patients receiving cytokine adsorption and those without.

CONCLUSION

 Data did not show a relevant effect of cytokine adsorption on neutrophil and monocyte activation during the first 48 hours after initiation of ECPR.

Hospital Acquired Sepsis, Disease Prevalence, and Recent Advances in Sepsis Mitigation

Sepsis is a life-threatening organ dysfunction caused by a dysregulated host response to infection, commonly associated with nosocomial transmission. Gram-negative bacterial species are particularly problematic due to the release of the lipopolysaccharide toxins upon cell death. The lipopolysaccharide toxin of E. coli has a greater immunogenic potential than that of other Gram-negative bacteria. The resultant dysregulation of the immune system is associated with organ failure and mortality, with pregnant women, ICU patients, and neonates being particularly vulnerable. Additionally, sepsis recovery patients have an increased risk of re-hospitalisation, chronic illness, co-morbidities, organ damage/failure, and a reduced life expectancy. The emergence and increasing prevalence of antimicrobial resistance in bacterial and fungal species has impacted the treatment of sepsis patients, leading to increasing mortality rates. Multidrug resistant pathogens including vancomycin-resistant Enterococcus, beta lactam-resistant Klebsiella, and carbapenem-resistant Acinetobacter species are associated with an increased risk of mortality. To improve the prognosis of sepsis patients, predominantly high-risk neonates, advances must be made in the early diagnosis, triage, and control of sepsis. The identification of suitable biomarkers and biomarker combinations, coupled with machine learning and artificial intelligence, show promise in early detection protocols. Rapid diagnosis of sepsis in patients is essential to inform on clinical treatment, especially with resistant infectious agents. This timely review aims to discuss sepsis prevalence, aetiology, and recent advances towards disease mitigation and control.

Clinical biomarker profiles reveals gender differences and mortality factors in sepsis

Background

Sepsis is a major contributor to global morbidity and mortality, affecting millions each year. Notwithstanding the decline in sepsis incidence and mortality over decades, gender disparities in sepsis outcomes persist, with research suggesting higher mortality rates in males.

Methods

This retrospective study aims to delineate gender-specific clinical biomarker profiles impacting sepsis progression and mortality by examining sepsis cases and related clinical data from the past three years. Propensity score matching was used to select age-matched healthy controls for comparison.

Results

Among 265 sepsis patients, a significantly higher proportion were male (60.8%, P<0.001). While mortality did not significantly differ by gender, deceased patients were significantly older (mean 69 vs 43 years, P=0.003), more likely to have hypertension (54% vs 25%, P=0.019), and had higher SOFA scores (mean ~10 vs 4, P<0.01) compared to survivors. Principal Component Analysis (PCA) showed clear separation between sepsis patients and healthy controls. 48 serum biomarkers were significantly altered in sepsis, with Triiodothyronine, Apolipoprotein A, and Serum cystatin C having the highest diagnostic value by ROC analysis. Gender-stratified comparisons identified male-specific (e.g. AFP, HDLC) and female-specific (e.g. Rheumatoid factor, Interleukin-6) diagnostic biomarkers. Deceased patients significantly differed from survivors, with 22 differentially expressed markers; Antithrombin, Prealbumin, HDL cholesterol, Urea nitrogen and Hydroxybutyrate had the highest diagnostic efficiency for mortality.

Conclusion

These findings enhance our understanding of gender disparities in sepsis and may guide future therapeutic strategies. Further research is warranted to validate these biomarker profiles and investigate the molecular mechanisms underlying these gender differences in sepsis outcomes.

Pentraxin-3 and Outcomes in CKD: A Systematic Review and Meta-analysis

Rationale & Objective

Long pentraxin-3 (PTX-3) serves as a biomarker for prognosticating adverse clinical outcomes in individuals with chronic kidney disease (CKD). The objective of the current meta-analysis was to evaluate the prognostic efficacy of PTX-3 in patients with CKD. In addition, we compared the prognostic effectiveness of PTX-3 and the short pentraxin C-reactive protein (CRP) in the identical cohort of patients with CKD.

Study Design

A systematic review and meta-analysis.

Setting & Participants

Patients with CKD treated with or without dialysis.

Selection Criteria for Studies

A cohort study with a minimum 1-year follow-up.

Data Extraction

Risk measurements, adjusted hazard risk with 95% CI, and modified variables.

Analytical Approach

To aggregate the adjusted effect estimates, a fixed-effects or random-effects model was employed.

Results

Nine studies covering 1,825 patients with CKD were selected in the present review. Six of the 9 studies exclusively included patients receiving hemodialysis. The collected findings indicated that patients with CKD in the highest tertile of PTX-3 demonstrated significantly higher risks of all-cause mortality (HR, 1.92; 95% CI, 1.44-2.56), cardiovascular death (HR, 1.98; 95% CI, 1.28-3.05), infectious death (HR, 5.26; 95% CI, 1.60-17.31), and fatal and nonfatal cardiovascular events (HR, 1.81; 95% CI, 1.35-2.42), as compared with those in the lowest tertile. These significant associations with risk were also observed when effect estimates were presented as per unit change in the PTX-3. Moreover, when comparing the prognostic value of PTX-3 and CRP in the same individuals (5 studies covering 904 patients), PTX-3 proved to be a satisfactory predictor of adverse events in these patients, whereas CRP failed to exhibit such predictive capability, regardless of the type of effect estimate used.

Limitations

A relatively small sample size and some heterogeneity.

Conclusions

Pentraxin 3 is associated with adverse events in individuals with CKD and may be a more reliable predictor of adverse clinical events than CRP in this population.

Analysis of the diagnostic and prognostic value of serum PAD2 in patients with sepsis in the intensive care unit

BACKGROUND

Sepsis is a common disease in the intensive care unit (ICU). In recent years, the incidence rate and mortality rate remain high. Early diagnosis of sepsis is crucial for treatment and can effectively reduce mortality. So far, the ability of serum peptidylarginine deaminase 2 (PAD2) in the diagnosis and prognosis of sepsis patients is still unclear. We conducted this study to reveal the clinical value of PAD2 as a biomarker for sepsis patients.

METHODS

A prospective study method was used to select 207 patients in the ICU of Renmin Hospital of Wuhan University from May 2022 to May 2023. They were divided into the sepsis group (n = 135) and control group (n = 72), and data were collected within 24 h of hospitalization. Sepsis patients were divided into a survival group (n = 80) and a non-survival group (n = 55) based on their 28-day survival status. Using statistical methods to evaluate the diagnostic and prognostic value of PAD2 in sepsis.

RESULTS

The serum PAD2 concentrations in the sepsis group were significantly higher than in the control group (median 16.70 vs 35.32 ng/ml, P < 0.001). Multivariate logistic regression analysis showed that the Quick Sequential Organ Failure Assessment (qSOFA), C-reactive protein (CRP), procalcitonin (PCT), and PAD2 were independent risk factors for sepsis. The Receiver operating characteristic (ROC) curve showed that the combined diagnostic value of qSOFA, CRP, PCT, and PAD2 was the highest. The serum PAD2 concentrations in the non-survival group of patients with sepsis were significantly higher than those in the survival group (median 29.26 vs 50.08 ng/ml, P < 0.05). The COX regression analysis showed that PAD2, sequential organ failure score Assessment (SOFA) score, and Acute Physiology and Chronic Health Evaluation (APACHE II) score were independent factors affecting the prognosis of sepsis patients. The ROC analysis showed that the combined prognostic value of PAD2, SOFA, and APACHE II scores was significantly higher than any single indicator. The Kaplan-Meier survival analysis showed that patients with PAD2 ≤ 48.62 ng/ml had a better prognosis.

CONCLUSION

The significant increase in serum PAD2 concentrations in patients is an independent risk factor affecting the occurrence of sepsis and 28-day mortality. The combination of PAD2 and other indicators can further improve the diagnostic and prognostic value for ICU sepsis patients.

Novel rapid method for identifying and quantifying pathogenic bacteria within four hours of blood collection

Sepsis is life-threatening organ dysfunction and is considered a major cause of health loss. However, since the current biomarkers of sepsis reflect the host's immune response to microorganisms, they would inevitably cause a time-lag. This means that there is still no truly reliable biomarker of sepsis. In the present study, we developed a novel method for identifying and quantifying unknown pathogenic bacteria within four hours of sample collection. The most important point of this study is that the novel method can be used to determine the number of bacteria in a sample as a novel biomarker of infectious diseases. Indeed, based on the number of bacteria, we were able to accurately estimate the severity of microbial infection. Furthermore, using the time-dependent changes in the number of bacteria, we were able to monitor the therapeutic effect accurately. The rapid identification and quantification of bacteria may change our approach to medical care.

Procalcitonin and C-reactive protein as diagnostic biomarkers in COVID-19 and Non-COVID-19 sepsis patients: a comparative study

BACKGROUND

This study aimed to assess and compare procalcitonin (PCT) and C-reactive protein (CRP) levels between COVID-19 and non-COVID-19 sepsis patients. Additionally, we evaluated the diagnostic efficiency of PCT and CRP in distinguishing between Gram-positive (GP) and Gram-negative (GN) bacterial infections. Moreover, we explored the associations of PCT with specific pathogens in this context.

METHODS

The study included 121 consecutive sepsis patients who underwent blood culture testing during the COVID-19 epidemic. PCT and CRP were measured, and reverse transcriptase-polymerase chain reaction (RT-PCR) was employed for the detection of COVID-19 nucleic acid. The Mann-Whitney U-test was used to compare PCT and CRP between the COVID-19 and non-COVID-19 groups. Receiver operating characteristic (ROC) curves were generated to compare PCT and CRP levels in the GN group versus the GP group for assessing the diagnostic efficiency. The kruskal-Wallis H test was applied to assess the impact of specific pathogen groups on PCT concentrations.

RESULTS

A total of 121 sepsis patients were categorized into a COVID-19 group (n = 25) and a non-COVID-19 group (n = 96). No significant differences in age and gender were observed between the COVID-19 and non-COVID-19 groups. The comparison of biomarkers between these groups showed no statistically significant differences. The optimal cut-off values for PCT and CRP in differentiating between GP and GN infections were 1.03 ng/mL and 34.02 mg/L, respectively. The area under the ROC curve was 0.689 (95% confidence interval (CI) 0.591-0.786) for PCT and 0.611 (95% CI 0.505-0.717) for CRP. The diagnostic accuracy was 69.42% for PCT and 58.69% for CRP. The study found a significant difference in PCT levels among specific groups of pathogens (P < 0.001), with the highest levels observed in Escherichia coli infections. The frequency of Staphylococcus spp. positive results was significantly higher (36.0%) in COVID-19 compared to non-COVID-19 sepsis patients (P = 0.047).

CONCLUSION

Sepsis patients with COVID-19 revealed a significantly higher culture positivity for staphylococcus spp. than the non-COVID-19 group. Both PCT and CRP showed moderate diagnostic efficiency in differentiating between GP and GN bacterial infections. PCT showed potential utility in identifying E. coli infections compared to other pathogens.

Role of LncRNAs in the Pathogenesis of Sepsis and their Clinical Significance

Sepsis is a fatal organ dysfunction caused by the host's uncontrolled response to infection, with high morbidity and mortality. Early diagnosis and intervention are the most effective methods to reduce the mortality due to sepsis. However, there is still a lack of definite biomarkers or intervention targets for the diagnosis, evaluation, prognosis, and treatment of sepsis. Long non-coding RNAs (lncRNAs) are a type of noncoding transcript with a length ranging from 200 to 100,000 nucleotides. LncRNAs mainly locate in the cytoplasm and nucleus and participate in various signaling pathways related to inflammatory reactions and organ dysfunction. Recent studies have reported that lncRNAs are involved in regulating the pathophysiological process of sepsis. Some classical lncRNAs have been confirmed as promising biomarkers to evaluate the severity and prognosis of sepsis. This review summarizes the mechanical studies on lncRNAs in sepsis-induced acute lung, kidney, myocardial, and liver injuries, analyzes the role of lncRNAs in the pathogenesis of sepsis, and explores the possibility of lncRNAs as potential biomarkers and intervention targets for sepsis-induced multiple organ dysfunction.

Inflammation and response to nutrition interventions

The complex interplay between nutrition and inflammation has become a major focus of research in recent years across different clinical settings and patient populations. Inflammation has been identified as a key driver for disease-related malnutrition promoting anorexia, reduced food intake, muscle loss, and on a cellular level, insulin resistance, which together stimulate catabolism. However, these effects may well be bidirectional, and there is strong evidence showing that nutrition influences inflammation. Several single nutrients and dietary patterns with either proinflammatory or anti-inflammatory properties have been studied, such as the long-chain ω-3 fatty acids eicosapentaenoic acid or docosahexaenoic acid. The Mediterranean diet combines several such nutrients and has been shown to improve medical outcomes in the outpatient setting. In addition, there is increasing evidence suggesting that inflammation affects the metabolism and modulates the response to nutrition support interventions. In fact, recent studies from the medical inpatient setting suggest that inflammation, mirrored by high levels of C-reactive protein, diminishes the positive effects of nutrition support. This may explain the lack of positive effects of some nutrition trials in severely ill patients, whereas similar approaches to nutritional support have shown positive results in less severely ill patients. The use of biomarkers, such as C-reactive protein, may help to identify patients with a lower response to nutrition, in whom other treatment options need to be used. There is need for additional research to understand how to best address the malnourished patient with inflammation by specifically lowering inflammation through anti-inflammatory medical treatments and/or nutrition interventions.

Plasma Insulin-like Growth Factor-Binding Protein-2 of Critically Ill Patients Is Related to Disease Severity and Survival

Insulin-like growth factor-binding protein (IGFBP)-2 regulates the bioactivity of the anabolic hormone's insulin-like growth factors, which are decreased in sepsis and contribute to the catabolic status of severely ill patients. The circulating levels of IGFBP-2 in critical illness have been rarely studied; therefore, we evaluated IGFBP-2 plasma levels in patients with systemic inflammatory response syndrome (SIRS) or sepsis as well as healthy controls. Our analysis of 157 SIRS/sepsis patients revealed higher plasma IGFBP-2 levels compared to 22 healthy controls. Plasma IGFBP-2 levels correlated positively with procalcitonin but not with C-reactive protein, interleukin-6, or the leukocyte count. Septic shock patients exhibited higher IGFBP-2 levels than those with SIRS. Bacterial or SARS-CoV-2 infection did not influence plasma IGFBP-2 levels. There was no difference in the IGFBP-2 levels between ventilated and non-ventilated SIRS/sepsis patients, and vasopressor therapy did not alter these levels. Dialysis patients had elevated plasma IGFBP-2 levels. Survivors had lower plasma IGFBP-2 levels than non-survivors. In conclusion, our study indicates that plasma IGFBP-2 levels are associated with disease severity, renal failure, and mortality in SIRS/sepsis patients.

Multi-modal sensing with integrated machine learning to differentiate specific leukocytes targeted by electrically sensitive hybrid particles

The growing need for personalized, accurate, and non-invasive diagnostic technology has resulted in significant advancements, from pushing current mechanistic limitations to innovative modality developments across various disease-related biomarkers. However, there still lacks clinical solutions for analyzing multiple biomarkers simultaneously, limiting prognosis for patients suffering with complicated diseases or comorbidities. Here, we conceived, fabricated, and validated a multifrequency impedance cytometry apparatus with novel frequency-sensitive barcoded metal oxide Janus particles (MOJPs) as cell-receptor targeting agents. These microparticles are modulated by a metal oxide semi-coating which exhibit electrical property changes in a multifrequency electric field and are functionalized to target CD11b and CD66b membrane proteins on neutrophils. A multi-modal system utilizing supervised machine learning and simultaneous high-speed video microscopy classifies immune-specific surface receptors targeted by MOJPs as they form neutrophil-MOJP conjugates, based on multivariate multifrequency electrical recordings. High precision and sensitivity were determined based on the type of MOJPs conjugated with cells (>90% accuracy between neutrophil-MOJP conjugates versus cells alone). Remarkably, the design could differentiate the number of MOJPs conjugated per cell within the same MOJP class (>80% accuracy); which also improved comparing electrical responses across different MOJP types (>75% accuracy) as well. Such trends were consistent in individual blood samples and comparing consolidated data across multiple samples, demonstrating design robustness. The configuration may further expand to include more MOJP types targeting critical biomarker receptors in one sample and increase the modality's multiplexing potential.

Predicting sepsis using a combination of clinical information and molecular immune markers sampled in the ambulance

Sepsis is a time dependent condition. Screening tools based on clinical parameters have been shown to increase the identification of sepsis. The aim of current study was to evaluate the additional predictive value of immunological molecular markers to our previously developed prehospital screening tools. This is a prospective cohort study of 551 adult patients with suspected infection in the ambulance setting of Stockholm, Sweden between 2017 and 2018. Initially, 74 molecules and 15 genes related to inflammation were evaluated in a screening cohort of 46 patients with outcome sepsis and 50 patients with outcome infection no sepsis. Next, 12 selected molecules, as potentially synergistic predictors, were evaluated in combination with our previously developed screening tools based on clinical parameters in a prediction cohort (n = 455). Seven different algorithms with nested cross-validation were used in the machine learning of the prediction models. Model performances were compared using posterior distributions of average area under the receiver operating characteristic (ROC) curve (AUC) and difference in AUCs. Model variable importance was assessed by permutation of variable values, scoring loss of classification as metric and with model-specific weights when applicable. When comparing the screening tools with and without added molecular variables, and their interactions, the molecules per se did not increase the predictive values. Prediction models based on the molecular variables alone showed a performance in terms of AUCs between 0.65 and 0.70. Among the molecular variables, IL-1Ra, IL-17A, CCL19, CX3CL1 and TNF were significantly higher in septic patients compared to the infection non-sepsis group. Combing immunological molecular markers with clinical parameters did not increase the predictive values of the screening tools, most likely due to the high multicollinearity of temperature and some of the markers. A group of sepsis patients was consistently miss-classified in our prediction models, due to milder symptoms as well as lower expression levels of the investigated immune mediators. This indicates a need of stratifying septic patients with a priori knowledge of certain clinical and molecular parameters in order to improve prediction for early sepsis diagnosis.Trial registration: NCT03249597. Registered 15 August 2017.

Rationale and Design of NEUTRALIZE-AKI: A Multicenter, Randomized, Controlled, Pivotal Study to Assess the Safety and Efficacy of a Selective Cytopheretic Device in Patients with Acute Kidney Injury Requiring Continuous Kidney Replacement Therapy

INTRODUCTION

NEUTRALIZE-AKI is a pivotal study to evaluate the safety and effectiveness of the selective cytopheretic device (SCD) in adult patients with acute kidney injury (AKI) requiring continuous kidney replacement therapy (CKRT).

METHODS/DESIGN

This is a two-arm, randomized, open-label, controlled multi-center pivotal US study which will enroll 200 adult patients (age 18-80 years) in the intensive care unit with acute kidney injury requiring CKRT and at least one additional organ failure across 30 clinical centers. Eligible patients will be randomized to CKRT plus SCD therapy versus CKRT alone. Therapy will be administered for up to 10 days, with the hypothesis that the CKRT plus SCD group will demonstrate a lower mortality rate or better rate of renal recovery than the CKRT alone group by day 90. The primary outcome is a composite of dialysis dependence or all-cause mortality at day 90.

CONCLUSION

The SCD is a cell-directed extracorporeal therapy that targets and deactivates pro-inflammatory neutrophils and monocytes, with evidence of efficacy across a variety of critically ill patient populations. Knowledge and experience from many of those studies and other AKI trials were incorporated into the design of this pivotal study, with the aim to investigate the role of effector cell immunomodulation in the intervention of AKI.

Plasma Chemerin Is Induced in Critically Ill Patients with Gram-Positive Infections

Chemerin is a chemoattractant protein abundantly expressed in hepatocytes. Chemerin exerts pro- and anti-inflammatory effects and acts as a pro-resolving protein. Chemerin levels are low in patients with liver cirrhosis and are increased in sepsis. The aim of this study was to identify associations between plasma chemerin levels and underlying diseases as well as causes of severe illness. The cohort included 32 patients with liver cirrhosis who had low systemic chemerin, and who were not considered for further evaluation. Plasma chemerin levels were similar between the 27 patients with systemic inflammatory response syndrome (SIRS), the 34 patients with sepsis and the 63 patients with septic shock. Chemerin in plasma correlated with C-reactive protein and leukocyte count but not with procalcitonin, a clinical marker of bacterial infection. Plasma chemerin did not differ among patients with and without ventilation and patients with and without dialysis. Vasopressor therapy was not associated with altered plasma chemerin levels. Infection with severe acute respiratory syndrome coronavirus 2 had no effect on plasma chemerin levels. Baseline levels of plasma chemerin could not discriminate between survivors and non-survivors. Notably, Gram-positive infection was associated with higher chemerin levels. In summary, the current study suggests that plasma chemerin might serve as an early biomarker for the diagnosis of Gram-positive infections in patients with sepsis.

Point-of-care diagnostics for sepsis using clinical biomarkers and microfluidic technology

Sepsis is a life-threatening immune response which is caused by a wide variety of sources and is a leading cause of mortality globally. Rapid diagnosis and appropriate antibiotic treatment are critical for successful patient outcomes; however, current molecular diagnostic techniques are time-consuming, costly and require trained personnel. Additionally, there is a lack of rapid point-of-care (POC) devices available for sepsis detection despite the urgent requirements in emergency departments and low-resource areas. Recent advances have been made toward developing a POC test for early sepsis detection that will be more rapid and accurate compared to conventional techniques. Within this context, this review discusses the use of current and novel biomarkers for early sepsis diagnosis using microfluidics devices for POC testing.

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.

28-day sepsis mortality prediction model from combined serial interleukin-6, lactate, and procalcitonin measurements: a retrospective cohort study

Sepsis is a global medical issue owing to its unacceptably high mortality rate. Therefore, an effective approach to predicting patient outcomes is critically needed. We aimed to search for a novel 28-day sepsis mortality prediction model based on serial interleukin-6 (IL-6), lactate (LAC), and procalcitonin (PCT) measurements. We enrolled 367 septic patients based on Sepsis-3 (Third International Consensus Definitions for Sepsis and Septic Shock). Serum IL-6, LAC, and PCT levels were measured serially. Results collected within 24 and 48-72 h of admission were marked as D1 and D3 (e.g., IL-6D1/D3), respectively; the IL-6, LAC, and PCT clearance (IL-6c, LACc, PCTc) at D3 were calculated. Data were split into training and validation cohorts (7:3). Logistic regression analyses were used to select variables to develop models and choose the best one according to the Akaike information criterion (AIC). Receiver operating characteristic curves (ROC), calibration plots, and decision curve analysis (DCA) were used to test model performance. A nomogram was used to validate the model. There were 314 (85.56%) survivors and 53 (14.44%) non-survivors. Logistic regression analyses showed that IL-6D1, IL-6D3, PCTD1, PCTD3, and LACcD3 could be used to develop the best prediction model. The areas under the curves (AUC) of the training (0.849, 95% CI: 0.787-0.911) and validation cohorts (0.828, 95% CI: 0.727-0.929), calibration plot, and the DCA showed that the model performed well. Thus, the predictive value of the risk nomogram was verified. Combining IL-6D1, IL-6D3, PCTD1, PCTD3, and LACcD3 may create an accurate prediction model for 28-day sepsis mortality. Multiple-center research with a larger quantity of data is necessary to determine its clinical utility.

Neutrophil CD64 index as a superior indicator for diagnosing, monitoring bacterial infection, and evaluating antibiotic therapy: a case control study

BACKGROUND

Neutrophil CD64 (nCD64) index has been widely studied as an indication of bacteria-infected diseases, but the exact usage of nCD64 index in monitoring infections remains debated. So this study aims to investigate the functionality of nCD64 index in tracking infections' progression and evaluating antibiotic therapy.

METHODS

160 participants (36 healthy controls, 34 culture-negative patients, 56 respiratory tract infected patients, and 34 bloodstream infected patients) were recruited and divided into groups. Data on nCD64 index, T lymphocyte subsets, and conventional indicators, including white blood cell count, neutrophil to lymphocyte ratio, procalcitonin, and C-reactive protein, were tested and compared.

RESULTS

Bacteria-infected patients had significantly higher nCD64 indexes (p < 0.05), especially patients with both bloodstream and respiratory tract infections. The nCD64 index could identify infected patients from culture-negative patients or controls, which conventional indicators cannot achieve. We followed up with 24 infected patients and found that their nCD64 indexes were promptly down-regulated after effective antibiotic therapy (3.16 ± 3.01 vs. 1.20 ± 1.47, p < 0.001).

CONCLUSION

The nCD64 index is a sensitive indicator for clinical diagnosis of bacterial infection, especially in monitoring infection and evaluating antibiotics' efficacy. Therefore, nCD64 has the potential to improve diagnostic accuracy and provide rapid feedback on monitoring disease progression in infected patients.

[A prospective randomized controlled study on the curative effects of enteral immunonutrition support therapy in adult burn patients at nutritional risk]

Objective: To explore the effects of enteral immunonutrition support therapy on nutritional metabolism, immune function, and inflammatory response in adult burn patients at nutritional risk as assessed by the modified 2nd nutrition risk screening (NRS) 2002. Methods: A prospective randomized controlled study was conducted. From December 2019 to January 2022, 500 adult patients who were admitted to the Affiliated Huaihai Hospital of Xuzhou Medical University and had nutritional risk assessed by the modified 2nd NRS 2002 were recruited into the study. According to burn severity, the patients were divided into common burn patients (n=450) and severe burn patients (n=50). According to the random number table, the patients with common burn were divided into common burn diet nutrition group and common burn diet enteral immunonutrition group, with 225 patients in each group, and the patients with severe burn were divided into severe burn diet enteral non-immunonutrition group and severe burn diet enteral immunonutrition group, with 25 patients in each group. The patients in each group were given the corresponding nutritional support therapies on the basis of routine burn treatment. On post injury day (PID) 1, 3, 7, 14, and 21, the total energy intake and total protein intake of the patients in 4 groups were recorded, the plasma prealbumin, albumin, transferrin, serum immunoglobulin A (IgA), IgG, IgM, peripheral blood CD3 positive T cell percentage, CD4 positive T cell count, CD8 positive T cell count, the ratio of CD4 positive T cells to CD8 positive T cells, natural killer cell percentage, plasma interleukin-6 (IL-6), free mitochondrial DNA (mtDNA) copy number, and soluble triggering receptor expressed on myeloid cells-1 (sTREM-1) of the patients in 4 groups were detected, and the nitrogen balance of the patients in 4 groups on the day was calculated. On PID 7, 14, and 21, the modified 2nd NRS 2002 scores of the patients in 4 groups were reassessed. The sepsis incidence during treatment and the length of hospital stay of the patients in 4 groups and the length of intensive care unit (ICU) stay of the patients in the 2 severe burn groups were recorded. Data were statistically analyzed with chi-square test, Fisher's exact probability test, Mann-Whitney U test, independent sample t test, analysis of variance for repeated measurement, and Bonferroni correction. Results: A total of 476 patients completed the trial, with 213 patients in common burn diet nutrition group (112 males and 101 females, aged (37±19) years), 218 patients in common burn diet enteral immunonutrition group (115 males and 103 females, aged (42±16) years), 22 patients in severe burn diet enteral non-immunonutrition group (11 males and 11 females, aged (35±8) years), and 23 patients in severe burn diet enteral immunonutrition group (12 males and 11 females, aged (35±8) years). Compared with those in common burn diet nutrition group, the patients in common burn diet enteral immunonutrition group had significantly higher total energy intake on PID 1 (t=6.06, P<0.01), significantly lower total energy intake on PID 7 and significantly lower total protein intake on PID 1 (with t values of 6.17 and 4.59, respectively,P<0.01). On PID 21, the total energy intake of patients in severe burn diet enteral immunonutrition group was significantly lower than that in severe burn diet enteral non-immunonutrition group (t=2.70, P<0.01). The total protein intake of patients in severe burn diet enteral immunonutrition group and severe burn diet enteral non-immunonutrition group were similar at each time point post injury (P>0.05). Compared with those in common burn diet nutrition group, the patients in common burn diet enteral immunonutrition group had significantly higher level of prealbumin on PID 3, 7, 14, and 21 (with t values of 2.05, 2.33, 2.45, and 2.11, respectively, P<0.05), significantly higher level of albumin on PID 7, 14, and 21 (with t values of 2.30, 2.56, and 2.15, respectively, P<0.05), significantly higher level of transferrin on PID 7 and 14 (with t values of 1.99 and 2.27, respectively, P<0.05), significantly higher nitrogen balance on PID 14 and 21 (with t values of 2.51 and 2.07, respectively, P<0.05), and significantly lower modified 2nd NRS 2002 score on PID 21 (t=1.99, P<0.05). Compared with those in severe burn diet enteral non-immunonutrition group, the patients in severe burn diet enteral immunonutrition group had significantly higher level of prealbumin on PID 3, 7, 14, and 21 (with t values of 2.50, 2.64, 2.18, and 2.39, respectively, P<0.05), significantly higher level of albumin​on PID 7, 14, and 21 (with t values of 2.27, 2.39, and 2.69, respectively, P<0.05), significantly higher level of transferrin and nitrogen balance but significantly lower modified 2nd NRS 2002 score on PID 14 and 21 (with t values of 2.30, 2.35, 2.41, 2.16, 2.31, and 2.73, respectively, P<0.05). Compared with those in common burn diet nutrition group, patients in common burn diet enteral immunonutrition group had significantly higher level of IgA and IgG on PID 7, 14, and 21 (with t values of 2.19, 2.36, 2.17, 2.49, 1.97, and 2.24, respectively, P<0.05), significantly higher level of IgM on PID 21 (t=2.06, P<0.05), significantly higher percentage of CD3 positive T cells and ratio of CD4 positive T cells to CD8 positive T cells on PID 3, 7, 14, and 21 (with t values of 2.49, 2.25, 2.33, 2.41, 2.39, 2.24, 2.46, and 2.18, respectively, P<0.05), significantly higher CD4 positive T cell count (with t values of 2.15 and 2.27, respectively, P<0.05) but significantly lower CD8 positive T cell count on PID 14 and 21 (with t values of 2.58 and 2.35, P<0.05), and significantly higher percentage of natural killer cells on PID 7, 14, and 21 (with t values of 2.53, 2.21, and 2.36, respectively, P<0.05). Compared with those in severe burn diet enteral non-immunonutrition group, patients in severe burn diet immunonutrition group had significantly higher level of IgA on PID 7 and 14 (with t values of 2.15 and 2.03, respectively, P<0.05), significantly higher level of IgG on PID 7, 14, and 21 (with t values of 2.09, 2.56, and 2.15, respectively, P<0.05), significantly higher level of IgM on PID 21 (t=2.08, P<0.05), significantly higher percentage of CD3 positive T cells, CD4 positive T cell count, and percentage of natural killer cells on PID 14 and 21 (with t values of 2.52, 2.14, 2.14, 2.39, 2.56, and 2.19, respectively, P<0.05), significantly lower CD8 positive T cell count but significantly higher ratio of CD4 positive T cells to CD8 positive T cells on PID 7, 14, and 21 (with t values of 2.27, 2.81, 2.01, 2.11, 2.69, and 2.05, respectively, P<0.05). Compared with those in common burn diet nutrition group, patients in common burn diet enteral immunonutrition group had significantly lower level of IL-6 (with t values of 2.34 and 2.32, respectively, P<0.05) and significantly lower free mtDNA copy number on PID 14 and 21 (with Z values of -2.28 and -2.34,respectively, P<0.05), significantly lower level of sTREM-1 on PID 7, 14, and 21 (with t values of 2.02, 2.94, and 3.72, respectively, P<0.05). Compared with those in severe burn diet enteral non-immunonutrition group, patients in severe burn diet enteral immunonutrition group had significantly lower level of IL-6 and sTREM-1 on PID 7, 14, and 21 (with t values of 2.15, 2.29, 2.47, 2.43, 2.07, and 2.32, respectively, P<0.05), and significantly lower free mtDNA copy number on PID 14 and 21 (with Z values of -2.49 and -2.21, respectively, P<0.05). During treatment, the sepsis incidences of patients in 2 common burn groups were similar (P>0.05), the sepsis incidences of patients in 2 severe burn groups were similar (P>0.05). The length of ICU stay of patients in severe burn diet enteral immunonutrition group was (11±3) d, which was significantly shorter than (14±3) d in severe burn diet enteral non-immunonutrition group (t=3.12, P<0.01). The length of hospital stay of patients in common burn diet enteral immunonutrition group was significantly shorter than that in common burn diet nutrition group (t=3.11, P<0.01). The length of hospital stay of patients in severe burn diet enteral non-immunonutrition group was similar to that in severe burn diet enteral immunonutrition group (P>0.05). Conclusions: Enteral immunonutrition support therapy for adult burn patients at nutritional risk assessed by the modified 2nd NRS 2002 can better improve the nutritional status and the immune function of patients, reduce inflammatory response of the body, and shorten the length of hospital stay in common burn patients and the length of ICU stay in severe burn patients.

Diagnostic accuracy of quick SOFA score and inflammatory biomarkers for predicting community-onset bacteremia

The potential use of quick SOFA (qSOFA) score and inflammatory biomarkers as bacteremia predictors is unelucidated. Herein the aim of this study was to evaluate the diagnostic accuracy of the qSOFA score and biomarkers for predicting community-onset bacteremia. We enrolled adult outpatients with blood culture samples drawn between 2018 and 2020. Contamination, intensive care unit admission, and hemodialysis were excluded. We performed a case-control study, and analyzed 115 patients (58 with bacteremia and 57 without bacteremia). The positive likelihood ratio (LR) for bacteremia was 2.46 (95% confidence interval [CI] 0.76–9.05) for a qSOFA score ≥ 2, and 4.07 (95% CI 1.92–9.58) for tachypnea (≥ 22/min). The highest performing biomarkers were procalcitonin (area under the curve [AUC] 0.80; 95% CI 0.72–0.88), followed by presepsin (AUC 0.69; 95% CI 0.60–0.79), and C-reactive protein (AUC 0.60; 95% CI 0.49–0.70). The estimated optimal cut-off value of procalcitonin was 0.377 ng/mL, with a sensitivity of 74.1%, a specificity of 73.7%, and a positive LR of 2.82. Presepsin was 407 pg/mL, with a sensitivity of 60.3%, a specificity of 75.4%, and a positive LR of 2.46. Procalcitonin was found to be a modestly useful biomarker for predicting non-severe community-onset bacteremia. Tachypnea (≥ 22/min) itself, rather than the qSOFA score, can be a diagnostic predictor. These predictors may aid decision-making regarding the collection of blood culture samples in the emergency department and outpatient clinics.

Non-Coding RNA Networks as Potential Novel Biomarker and Therapeutic Target for Sepsis and Sepsis-Related Multi-Organ Failure

According to “Sepsis-3” consensus, sepsis is a life-threatening clinical syndrome caused by a dysregulated inflammatory host response to infection. A rapid identification of sepsis is mandatory, as the extent of the organ damage triggered by both the pathogen itself and the host’s immune response could abruptly evolve to multiple organ failure and ultimately lead to the death of the patient. The most commonly used therapeutic strategy is to provide hemodynamic and global support to the patient and to rapidly initiate broad-spectrum empiric antibiotic therapy. To date, there is no gold standard diagnostic test that can ascertain the diagnosis of sepsis. Therefore, once sepsis is suspected, the presence of organ dysfunction can be assessed using the Sepsis-related Organ Failure Assessment (SOFA) score, although the diagnosis continues to depend primarily on clinical judgment. Clinicians can now rely on several serum biomarkers for the diagnosis of sepsis (e.g., procalcitonin), and promising new biomarkers have been evaluated, e.g., presepsin and adrenomedullin, although their clinical relevance in the hospital setting is still under discussion. Non-codingRNA, including long non-codingRNAs (lncRNAs), circularRNAs (circRNAs) and microRNAs (miRNAs), take part in a complex chain of events playing a pivotal role in several important regulatory processes in humans. In this narrative review we summarize and then analyze the function of circRNAs-miRNA-mRNA networks as putative novel biomarkers and therapeutic targets for sepsis, focusing only on data collected in clinical settings in humans.

Biomarker combinations in predicting sepsis in hospitalized children with fever

Sepsis is among the leading causes of critical illness worldwide. It includes physiologic, pathologic, and biochemical abnormalities, induced by infection. Novel methods for recognizing a dysregulated inflammatory response and predicting associated mortality must be developed. Our aim was to investigate biomarkers that characterize a pro-inflammatory and anti-inflammatory response in patients with fever by comparing predictive validity for sepsis. 165 patients with fever were enrolled in this study, 55 of them had sepsis according to pSOFA criteria. All patients had blood samples drawn at the time of inclusion and after 24 h. CRP, PCT and also IL-6, IL-8 and sFAS levels were significantly higher in patients with sepsis. The AUC of CRP to predict sepsis was 0.799, all the other biomarkers had AUC's lower than that. Cytokines, when used as a single marker, did not show a significant diagnostic performance We analyzed various models of biomarker combinations. CRP combined with sFAS showed increase in sensitivity in predicting sepsis (88% vs. 83%). The highest AUC was achieved, when CRP, IL-6, sFAS and sVCAM-1 markers were combined 0.830 (95% CI 0.762-0.884) with a sensitivity of 70% and specificity of 84%. vs. 0.799 for CRP alone.

The Association between Regulatory T Cell Subpopulations and Severe Pneumonia Post Renal Transplantation

Severe pneumonia accounts for the majority of morbidity and mortality in renal allograft recipients due to immunosuppressant maintenance. Regulatory T cells (Tregs), which are involved in tackling infections under immunosuppressive conditions, are rarely uncovered. We aimed to investigate the relationship between various Treg subpopulations and severe pneumonia after kidney transplantation (KTx). KTx recipients with pneumonia were divided into severe pneumonia and mild pneumonia groups. The frequencies and absolute numbers (Ab No.) of total Tregs (CD4+CD25+FoxP3+), six subsets of Tregs (Helios+/-, CD39+/-, and CD45RA+/-), and T cells, B cells, and NK cells were assessed from peripheral blood via flow cytometry using the $t$ or Mann-Whitney test and receiver operating curve analysis. We also determined the median fluorescence intensity (MFI) of human leukocyte antigen- (HLA-) DR on monocytes and CD64 on neutrophils. Logistic regression was used to identify the risk factors of disease progression, and Pearson’s correlation analysis was performed to identify relationships between the measured immune indices and patients’ clinical information. Our research indicated that Treg subpopulations were strongly associated with severe pneumonia progression post KTx. Based on the monitoring of Treg subpopulations, better-individualized prevention and therapy might be achieved for patients with severe pneumonia post KTx.

Identification of a novel four-gene diagnostic signature for patients with sepsis by integrating weighted gene co-expression network analysis and support vector machine algorithm

Sepsis is a life-threatening condition in which the immune response is directed towards the host tissues, causing organ failure. Since sepsis does not present with specific symptoms, its diagnosis is often delayed. The lack of diagnostic accuracy results in a non-specific diagnosis, and to date, a standard diagnostic test to detect sepsis in patients remains lacking. Therefore, it is vital to identify sepsis-related diagnostic genes. This study aimed to conduct an integrated analysis to assess the immune scores of samples from patients diagnosed with sepsis and normal samples, followed by weighted gene co-expression network analysis (WGCNA) to identify immune infiltration-related genes and potential transcriptome markers in sepsis. Furthermore, gene regulatory networks were established to screen diagnostic markers for sepsis based on the protein-protein interaction networks involving these immune infiltration-related genes. Moreover, we integrated WGCNA with the support vector machine (SVM) algorithm to build a diagnostic model for sepsis. Results showed that the immune score was significantly lower in the samples from patients with sepsis than in normal samples. A total of 328 and 333 genes were positively and negatively correlated with the immune score, respectively. Using the MCODE plugin in Cytoscape, we identified four modules, and through functional annotation, we found that these modules were related to the immune response. Gene Ontology functional enrichment analysis showed that the identified genes were associated with functions such as neutrophil degranulation, neutrophil activation in the immune response, neutrophil activation, and neutrophil-mediated immunity. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis showed the enrichment of pathways such as primary immunodeficiency, Th1- and Th2-cell differentiation, T-cell receptor signaling pathway, and natural killer cell-mediated cytotoxicity. Finally, we identified a four-gene signature, containing the hub genes LCK, CCL5, ITGAM, and MMP9, and established a model that could be used to diagnose patients with sepsis.

Antimicrobial Stewardship in the ICU

Increasing rates of infection and multidrug-resistant pathogens, along with a high use of antimicrobial therapy, make the intensive care unit (ICU) an ideal setting for implementing and supporting antimicrobial stewardship efforts. Overuse of antimicrobial agents is common in the ICU, as practitioners are challenged daily with achieving early, appropriate empiric antimicrobial therapy to improve patient outcomes. While early antimicrobial stewardship programs focused on the financial implications of antimicrobial overuse, current goals of stewardship programs align closely with those of critical care providers-to optimize patient outcomes, reduce development of resistance, and minimize adverse outcomes associated with antibiotic overuse and misuse such as acute kidney injury and Clostridioides difficile-associated disease. Significant opportunities exist in the ICU for critical care clinicians to support stewardship practices at the bedside, including thoughtful and restrained initiation of antimicrobial therapy, use of biomarkers in addition to rapid diagnostics, Staphylococcus aureus screening, and traditional microbiologic culture and susceptibilities to guide antibiotic de-escalation, and use of the shortest duration of therapy that is clinically appropriate. Integration of critical care practitioners into the initiatives of antimicrobial stewardship programs is key to their success. This review summarizes key components of antimicrobial stewardship programs and mechanisms for critical care practitioners to share the responsibility for antimicrobial stewardship.

Therapeutic Drug Monitoring of Antibiotic Drugs: The Role of the Clinical Laboratory

BACKGROUND

Therapeutic drug monitoring (TDM) of anti-infective drugs is an increasingly complex field, given that in addition to the patient and drug as 2 usual determinants, its success is driven by the pathogen. Pharmacodynamics is related both to the patient (toxicity) and bacterium (efficacy or antibiotic susceptibility). The specifics of TDM of antimicrobial drugs stress the need for multidisciplinary knowledge and expertise, as in any other field. The role and the responsibility of the laboratory in this interplay are both central and multifaceted. This narrative review highlights the role of the clinical laboratory in the TDM process.

METHODS

A literature search was conducted in PubMed and Google Scholar, focusing on the past 5 years (studies published since 2016) to limit redundancy with previously published review articles. Furthermore, the references cited in identified publications of interest were screened for additional relevant studies and articles.

RESULTS

The authors addressed microbiological methods to determine antibiotic susceptibility, immunochemical and chromatographic methods to measure drug concentrations (primarily in blood samples), and endogenous clinical laboratory biomarkers to monitor treatment efficacy and toxicity. The advantages and disadvantages of these methods are critically discussed, along with existing gaps and future perspectives on strategies to provide clinicians with as reliable and useful results as possible.

CONCLUSIONS

Although interest in the field has been the driver for certain progress in analytical technology and quality in recent years, laboratory professionals and commercial providers persistently encounter numerous unresolved challenges. The main tasks that need tackling include broadly and continuously available, easily operated, and cost-effective tests that offer short turnaround times, combined with reliable and easy-to-interpret results. Various fields of research are currently addressing these features.

The Interplay between Host Defense, Infection, and Clinical Status in Septic Patients: A Narrative Review

Sepsis is a life-threatening condition that arises when the body's response to an infection injures its own tissues and organs. Despite significant morbidity and mortality throughout the world, its pathogenesis and mechanisms are not clearly understood. In this narrative review, we aimed to summarize the recent developments in our understanding of the hallmarks of sepsis pathogenesis (immune and adaptive immune response, the complement system, the endothelial disfunction, and autophagy) and highlight novel laboratory diagnostic approaches. Clinical management is also discussed with pivotal consideration for antimicrobic therapy management in particular settings, such as intensive care unit, altered renal function, obesity, and burn patients.

Translation of Pharmacodynamic Biomarkers of Antibiotic Efficacy in Specific Populations to Optimize Doses

Antibiotic efficacy determination in clinical trials often relies on non-inferiority designs because they afford smaller study sample sizes. These efficacy studies tend to exclude patients within specific populations or include too few patients to discern potential differences in their clinical outcomes. As a result, dosing guidance in patients with abnormal liver and kidney function, age across the lifespan, and other specific populations relies on drug exposure-matching. The underlying assumption for exposure-matching is that the disease course and the response to the antibiotic are similar in patients with and without the specific condition. While this may not be the case, clinical efficacy studies are underpowered to ensure this is true. The current paper provides an integrative review of the current approach to dose selection in specific populations. We review existing clinical trial endpoints that could be measured on a more continuous rather than a discrete scale to better inform exposure-response relationships. The inclusion of newer systemic biomarkers of efficacy can help overcome the current limitations. We use a modeling and simulation exercise to illustrate how an efficacy biomarker can inform dose selection better. Studies that inform response-matching rather than exposure-matching only are needed to improve dose selection in specific populations.

Long Non-Coding RNAs as Biomarkers and Therapeutic Targets in Sepsis

Sepsis, an infection-induced systemic inflammatory disorder, is often accompanied by multiple organ dysfunction syndromes with high incidence and mortality rates, and those who survive are often left with long-term sequelae, bringing great burden to social economy. Therefore, novel approaches to solve this puzzle are urgently needed. Previous studies revealed that long non-coding RNAs (lncRNAs) have exerted significant influences on the process of sepsis. The aim of this review is to summarize our understanding of lncRNAs as potential sepsis-related diagnostic markers and therapeutic targets, and provide new insights into the diagnosis and treatment for sepsis. In this study, we also introduced the current diagnostic markers of sepsis and discussed their limitations, while review the research advances in lncRNAs as promising biomarkers for diagnosis and prognosis of sepsis. Furthermore, the roles of lncRNAs in sepsis-induced organ dysfunction were illustrated in terms of different organ systems. Nevertheless, further studies should be carried out to elucidate underlying molecular mechanisms and pathological process of sepsis.

Presepsin as Early Marker of Sepsis in Emergency Department: A Narrative Review

The diagnosis and treatment of sepsis have always been a challenge for the physician, especially in critical care setting such as emergency department (ED), and currently sepsis remains one of the major causes of mortality. Although the traditional definition of sepsis based on systemic inflammatory response syndrome (SIRS) criteria changed in 2016, replaced by the new criteria of SEPSIS-3 based on organ failure evaluation, early identification and consequent early appropriated therapy remain the primary goal of sepsis treatment. Unfortunately, currently there is a lack of a foolproof system for making early sepsis diagnosis because conventional diagnostic tools like cultures take a long time and are often burdened with false negatives, while molecular techniques require specific equipment and have high costs. In this context, biomarkers, such as C-Reactive Protein (CRP) and Procalcitonin (PCT), are very useful tools to distinguish between normal and pathological conditions, graduate the disease severity, guide treatment, monitor therapeutic responses and predict prognosis. Among the new emerging biomarkers of sepsis, Presepsin (P-SEP) appears to be the most promising. Several studies have shown that P-SEP plasma levels increase during bacterial sepsis and decline in response to appropriate therapy, with sensitivity and specificity values comparable to those of PCT. In neonatal sepsis, P-SEP compared to PCT has been shown to be more effective in diagnosing and guiding therapy. Since in sepsis the P-SEP plasma levels increase before those of PCT and since the current methods available allow measurement of P-SEP plasma levels within 17 min, P-SEP appears a sepsis biomarker particularly suited to the emergency department and critical care.

Independent Validation of Sepsis Index for Sepsis Screening in the Emergency Department

(1) Background: The early detection of sepsis is still challenging, and there is an urgent need for biomarkers that could identify patients at a high risk of developing it. We recently developed an index, namely the Sepsis Index (SI), based on the combination of two CBC parameters: monocyte distribution width (MDW) and mean monocyte volume (MMV). In this study, we sought to independently validate the performance of SI as a tool for the early detection of patients at a high risk of sepsis in the Emergency Department (ED). (2) Methods: We enrolled all consecutive patients attending the ED with a request of the CBC. MDW and MMV were measured on samples collected in K3-EDTA tubes on the UniCel DxH 900 haematology analyser. SI was calculated based on the MDW and MMV. (3) Results: We enrolled a total of 703 patients stratified into four subgroups according to the Sepsis-2 criteria: control (498), infection (105), SIRS (52) and sepsis (48). The sepsis subgroup displayed the highest MDW (median 27.5, IQR 24.6-32.9) and SI (median 1.15, IQR 1.05-1.29) values. The ROC curve analysis for the prediction of sepsis showed a good and comparable diagnostic accuracy of the MDW and SI. However, the SI displayed an increased specificity, positive predictive value and positive likelihood ratio in comparison to MDW alone. (4) Conclusions: SI improves the diagnostic accuracy of MDW for sepsis screening.

Antibody Protection against Long-Term Memory Loss Induced by Monomeric C-Reactive Protein in a Mouse Model of Dementia

Monomeric C-reactive protein (mCRP), the activated isoform of CRP, induces tissue damage in a range of inflammatory pathologies. Its detection in infarcted human brain tissue and its experimentally proven ability to promote dementia with Alzheimer's disease (AD) traits at 4 weeks after intrahippocampal injection in mice have suggested that it may contribute to the development of AD after cerebrovascular injury. Here, we showed that a single hippocampal administration of mCRP in mice induced memory loss, lasting at least 6 months, along with neurodegenerative changes detected by increased levels of hyperphosphorylated tau protein and a decrease of the neuroplasticity marker Egr1. Furthermore, co-treatment with the monoclonal antibody 8C10 specific for mCRP showed that long-term memory loss and tau pathology were entirely avoided by early blockade of mCRP. Notably, 8C10 mitigated Egr1 decrease in the mouse hippocampus. 8C10 also protected against mCRP-induced inflammatory pathways in a microglial cell line, as shown by the prevention of increased generation of nitric oxide. Additional in vivo and in vitro neuroprotective testing with the anti-inflammatory agent TPPU, an inhibitor of the soluble epoxide hydrolase enzyme, confirmed the predominant involvement of neuroinflammatory processes in the dementia induced by mCRP. Therefore, locally deposited mCRP in the infarcted brain may be a novel biomarker for AD prognosis, and its antibody blockade opens up therapeutic opportunities for reducing post-stroke AD risk.

Novel Diagnostics and Therapeutics in Sepsis

Sepsis management demands early diagnosis and timely treatment that includes source control, antimicrobial therapy, and resuscitation. Currently employed diagnostic tools are ill-equipped to rapidly diagnose sepsis and isolate the offending pathogen, which limits the ability to offer targeted and lowest-toxicity treatment. Cutting edge diagnostics and therapeutics in development may improve time to diagnosis and address two broad management principles: (1) source control by removing the molecular infectious stimulus of sepsis, and (2) attenuation of the pathological immune response allowing the body to heal. This review addresses novel diagnostics and therapeutics and their role in the management of sepsis.

Host Diagnostic Biomarkers of Infection in the ICU: Where Are We and Where Are We Going?

Purpose of Review

Early identification of infection in the critically ill patient and initiation of appropriate treatment is key to reducing morbidity and mortality. On the other hand, the indiscriminate use of antimicrobials leads to harms, many of which may be exaggerated in the critically ill population. The current method of diagnosing infection in the intensive care unit relies heavily on clinical gestalt; however, this approach is plagued by biases. Therefore, a reliable, independent biomarker holds promise in the accurate determination of infection. We discuss currently used host biomarkers used in the intensive care unit and review new and emerging approaches to biomarker discovery.

Recent Findings

White cell count (including total white cell count, left shift, and the neutrophil-leucocyte ratio), C-reactive protein, and procalcitonin are the most common host diagnostic biomarkers for sepsis used in current clinical practice. However, their utility in the initial diagnosis of infection, and their role in the subsequent decision to commence treatment, remains limited. Novel approaches to biomarker discovery that are currently being investigated include combination biomarkers, host 'sepsis signatures' based on differential gene expression, site-specific biomarkers, biomechanical assays, and incorporation of new and pre-existing host biomarkers into machine learning algorithms.

Summary

To date, no single reliable independent biomarker of infection exists. Whilst new approaches to biomarker discovery hold promise, their clinical utility may be limited if previous mistakes that have afflicted sepsis biomarker research continue to be repeated.