Clinical application of sepsis biomarkers

Diagnostic capacity of miRNAs in neonatal sepsis: a systematic review and meta-analysis

BACKGROUND

Neonatal sepsis is the third leading cause of mortality during the neonatal period, with manifestations atypical and obscure. But the gold standard-blood culture test, requiring 3-5 days, makes it difficult to unveil the final pathogen and leads to the increasing ratio of false-negative results. The empirical method is consulting traditional biomarkers, such as procalcitonin (PCT), C-reactive protein (CRP), and white blood cell count. However, they are not specific for neonate in diagnostic capacity, especially for infants within three days after delivery, so more novel biomarkers are urgently needed to assist diagnosing neonatal sepsis. microRNAs (miRNAs) have been widely studied in recent years for their diagnostic and prognostic values in different diseases and we conducted a meta-analysis of miRNAs on the topic that whether they are potentially novel biomarkers in early detection of neonatal sepsis.

OBJECTIVES

The purpose of the study was to assess whether circulating miRNAs could be used as potential biomarkers for neonatal sepsis, including early and late-onset neonatal sepsis, then calculate their overall accuracy (OA) via meta-analysis.

METHODS

PubMed, Cochrane Library, Embase, Web of Science, Scopus, and Ovid databases were retrieved; data cutoff for this analysis was 15 January 2023. Methodological quality assessment of included studies was performed through the Quality in Prognostic Studies tool. Corresponding 95% confidence interval (95%CI) was calculated to present miRNAs' diagnostic value including the pooled sensitivity (Sen), specificity (Spe), positive or negative likelihood ratios (PLR or NLR), diagnostic odds ratio (DOR), and area under the curve (AUC). Differences in OA between the septic group and non-septic group were compared using Chi-square test.

RESULTS

After identification, 16 records out of 11 selected articles were eligible for systematic review of miRNAs and four records for PCT; the case group for miRNAs included 945 neonatal sepsis cases; contrast group included 190 respiratory tract infections or pneumonia cases, 60 systemic inflammatory response syndrome (SIRS) cases and 559 healthy neonates. The pooled Sen, Spe, and DOR of miRNAs were 0.87 (95%CI 0.81-0.91), 0.79 (95%CI 0.71-0.85), and 24 (95%CI 12-50), respectively. The pooled Sen, Spe, and DOR of PCT were 0.92 (95%CI 0.83-0.96), 0.64 (95%CI 0.56-0.70), and 20 (95%CI, 7-56), respectively. The OA value of miRNAs was 80.38% and that of PCT was 77.36%, which were not statistically significant difference (p = .13) after the Chi-square test. In addition, no significant publication bias was indicated (p = .92).

CONCLUSIONS

Circulating miRNA levels could be applied as diagnostic biomarkers in neonatal sepsis.

Advances in sepsis biomarkers

Sepsis, a dysregulated host immune response to an infectious agent, significantly increases morbidity and mortality for hospitalized patients worldwide. This chapter reviews (1) the basic principles of infectious diseases, pathophysiology and current definition of sepsis, (2) established sepsis biomarkers such lactate, procalcitonin and C-reactive protein, (3) novel, newly regulatory-cleared/approved biomarkers, such as assays that evaluate white blood cell properties and immune response molecules, and (4) emerging biomarkers and biomarker panels to highlight future directions and opportunities in the diagnosis and management of sepsis.

Basal procalcitonin, C-reactive protein, interleukin-6, and presepsin for prediction of mortality in critically ill septic patients: a systematic review and meta-analysis

BACKGROUND

Numerous biomarkers have been proposed for diagnosis, therapeutic, and prognosis in sepsis. Previous evaluations of the value of biomarkers for predicting mortality due to this life-threatening condition fail to address the complexity of this condition and the risk of bias associated with prognostic studies. We evaluate the predictive performance of four of these biomarkers in the prognosis of mortality through a methodologically sound evaluation.

METHODS

We conducted a systematic review a systematic review and meta-analysis to determine, in critically ill adults with sepsis, whether procalcitonin (PCT), C-reactive protein (CRP), interleukin-6 (IL-6), and presepsin (sCD14) are independent prognostic factors for mortality. We searched MEDLINE, EMBASE, and the Cochrane Central Register of Controlled Trials up to March 2023. Only Phase-2 confirmatory prognostic factor studies among critically ill septic adults were included. Random effects meta-analyses pooled the prognostic association estimates.

RESULTS

We included 60 studies (15,681 patients) with 99 biomarker assessments. Quality of the statistical analysis and reporting domains using the QUIPS tool showed high risk of bias in > 60% assessments. The biomarker measurement as a continuous variable in models adjusted by key covariates (age and severity score) for predicting mortality at 28-30 days showed a null or near to null association for basal PCT (pooled OR = 0.99, 95% CI = 0.99-1.003), CRP (OR = 1.01, 95% CI = 0.87 to 1.17), and IL-6 (OR = 1.02, 95% CI = 1.01-1.03) and sCD14 (pooled HR = 1.003, 95% CI = 1.000 to 1.006). Additional meta-analyses accounting for other prognostic covariates had similarly null findings.

CONCLUSION

Baseline, isolated measurement of PCT, CRP, IL-6, and sCD14 has not been shown to help predict mortality in critically ill patients with sepsis. The role of these biomarkers should be evaluated in new studies where the patient selection would be standardized and the measurement of biomarker results.

TRIAL REGISTRATION

PROSPERO (CRD42019128790).

Real-Time, In Vivo Molecular Monitoring Using Electrochemical Aptamer Based Sensors: Opportunities and Challenges

The continuous, real-time measurement of specific molecules in situ in the body would greatly improve our ability to understand, diagnose, and treat disease. The vast majority of continuous molecular sensing technologies, however, either (1) rely on the chemical or enzymatic reactivity of their targets, sharply limiting their scope, or (2) have never been shown (and likely will never be shown) to operate in the complex environments found in vivo. Against this background, here we review electrochemical aptamer-based (EAB) sensors, an electrochemical approach to real-time molecular monitoring that has now seen 15 years of academic development. The strengths of the EAB platform are significant: to date it is the only molecular measurement technology that (1) functions independently of the chemical reactivity of its targets, and is thus general, and (2) supports in vivo measurements. Specifically, using EAB sensors we, and others, have already reported the real-time, seconds-resolved measurements of multiple, unrelated drugs and metabolites in situ in the veins and tissues of live animals. Against these strengths, we detail the platform's remaining weaknesses, which include still limited measurement duration (hours, rather than the more desirable days) and the difficulty in obtaining sufficiently high performance aptamers against new targets, before then detailing promising approaches overcoming these hurdles. Finally, we close by exploring the opportunities we believe this potentially revolutionary technology (as well as a few, possibly competing, technologies) will create for both researchers and clinicians.

A Pilot Assessment on the Role of Procalcitonin Dynamic Monitoring in the Early Diagnosis of Infection Post Cardiac Surgery

Purpose

To evaluate the value of dynamic monitoring of procalcitonin (PCT) as a biomarker for the early diagnosis of postoperative infections in patients undergoing cardiac surgery.

Methods

In total, 252 patients who underwent cardiac surgery were retrospectively included. The postoperative patients’ PCT level, change value (△PCT), and clearance rate (△PCTc) were compared between the infected and noninfected groups in adult and pediatric patients on postoperative days (PODs) 1, 3, and 5. The area under the receiver operating characteristic (ROC) curve (AUC) was used to evaluate the diagnostic value.

Results

Procalcitonin concentration decreased progressively in the noninfected group in adult and pediatric patients; PCT concentration continued to rise until it peaked on POD 3 in the infected group. In adult patients, the AUC of PCT for diagnosis of infection on PODs 1, 3, and 5 were 0.626, 0.817, and 0.806, with the optimal cut-off values of 7.35, 3.63, and 1.73 ng/ml, respectively. The diagnostic efficiency of △PCT₃ and △PCT_C3 was significantly better than △PCT₅ and △PCT_C5, respectively. In pediatric patients, the AUC of PCT for diagnosis of infection on PODs 1, 3, and 5 were 0.677, 0.747, and 0.756, respectively, and the optimal cut-off values were 27.62, 26.15, and 10.20 ng/ml.

Conclusion

This study showed that dynamic monitoring of PCT levels could be an effective clinical means to help to discover postoperative infection earlier. The PCT level and its change indicators on POD 3 in adult patients and the PCT level on POD 5 in children can indicate infection.

Antimicrobial Stewardship Using Biomarkers: Accumulating Evidence for the Critically Ill

This review aims to summarize current progress in the management of critically ill, using biomarkers as guidance for antimicrobial treatment with a focus on antimicrobial stewardship. Accumulated evidence from randomized clinical trials (RCTs) and observational studies in adults for the biomarker-guided antimicrobial treatment of critically ill (mainly sepsis and COVID-19 patients) has been extensively searched and is provided. Procalcitonin (PCT) is the best studied biomarker; in the majority of randomized clinical trials an algorithm of discontinuation of antibiotics with decreasing PCT over serial measurements has been proven safe and effective to reduce length of antimicrobial treatment, antibiotic-associated adverse events and long-term infectious complications like infections by multidrug-resistant organisms and Clostridioides difficile. Other biomarkers, such as C-reactive protein and presepsin, are already being tested as guidance for shorter antimicrobial treatment, but more research is needed. Current evidence suggests that biomarkers, mainly procalcitonin, should be implemented in antimicrobial stewardship programs even in the COVID-19 era, when, although bacterial coinfection rate is low, antimicrobial overconsumption remains high.

MicroRNA Expression in Neonates with Late-onset Sepsis - A Cross-sectional Comparative Study

BACKGROUND

Neonatal sepsis is a major health concern among neonates with higher morbidity and mortality rate. Studies have recently speculated the importance of differential expression of circulating mature micro-RNAs (miRNAs) which could serve as diagnostic as well as prognostic markers for risk of mortality in neonatal sepsis. This study aimed to analyze the expression pattern and to assess the diagnostic/prognostic value of miRNAs miR-21, miR-29a miR-31, miR-146a, and miR-155 in late-onset neonatal sepsis.

METHODS

A cross-sectional comparative study was conducted including 42 healthy controls and 42 neonates with late-onset neonatal sepsis. SYBR green-based miScript RT-PCR assay was used for the expression analysis and the comparative Ct method 2-delta (Ct) method was used for relative quantification of the candidate miRNAs in plasma. Significantly higher expression of miR-21 and miR-155 and lower expression of miR-29a and miR-146a was observed in cases compared to control except miR-31. In subgroups analysis, miR-21(p = .03) showed a significant difference between pre-term and term neonates and miR-31 (p = .01) and miR-155 (p = .03) showed a significant difference between low-birth-weight and normal-birth-weight neonates. miR-146a showed significantly lower expression in the non-survivor group compared to the survivor group (p = .005). A receiver operating characteristic curve (ROC) analysis of miR-21 and miR-29a (0.829 and 0.787 AUC of ROC curves) showed good discrimination for the identification of sepsis from non-sepsis neonates.

CONCLUSION

The current study shows evidence of differential expression of miRNAs in neonatal sepsis and this altered expression of candidate miRNAs could be involved in immune dysregulation, thus leading to sepsis-related severity in newborns.

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.

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.

Cognitive Biases in the Era of COVID-19 : A Case of Clostridium sporogenes Bacteremia in a Patient with Small Bowel Obstruction

Clostridium sporogenes bacteremia in immunocompetent patients is rare with very few reported cases in the literature. We present a case of Clostridium sporogenes bacteremia in an 81-year-old immunocompetent man with small bowel obstruction and hypoxemia during the COVID-19 pandemic. Routine monitoring of prognostic inflammatory markers for COVID-19 created a unique challenge in the management of our patient who developed sepsis with respiratory symptoms. Upon review, bacteremia from Clostridium sporogenes was associated with high mortality rates and could produce similar elevations in the inflammatory markers observed in COVID-19 pneumonia. Further, we reviewed the cognitive biases encountered when monitoring these inflammatory markers during the management of our patient with Clostridium sporogenes bacteremia, who was initially thought to have COVID-19 disease. While our patient ultimately tested negative for COVID-19, early administration of empiric antimicrobial therapy without source control failed to prevent clinical decompensation.

Accuracy of circulating microRNAs in diagnosis of sepsis: a systematic review and meta-analysis

Objectives

The aim of this study was to systematically assess the accuracy of circulating microRNAs (miRNAs) as a promising biomarker for sepsis via a meta-analysis.

Methods

PubMed, Cochrane Library, Embase, Web of Science, Scopus, and Ovid databases were searched up to April 3, 2020. The Quality in Prognostic Studies (QUADAS-2) tool was used to assess methodological quality. The pooled sensitivity (Sen), specificity (Spe), positive or negative likelihood ratios (PLR or NLR), diagnostic odds ratio (DOR), curve, and area under the curve (AUC) were calculated with 95% confidence interval (95% CI). The overall accuracy (OA) of miRNAs, procalcitonin (PCT), and C-reactive protein (CRP) was analyzed by the chi-square test.

Results

A total of 22 records were eligible for systematic review, including 2210 sepsis, 426 systemic inflammatory response syndrome (SIRS), and 1076 healthy controls (HC). The pooled Sen, Spe, and DOR of miRNAs were 0.80 (95% CI 0.75–0.83), 0.85 (95% CI 0.80–0.89), and 22 (15–32), respectively. The DOR of PCT and CRP were 17 (95% CI 4–68) and 7 (95% CI 1–48), respectively. The OA value of miRNAs (79.02%) and PCT (76.95%) were higher than CRP (61.22%) (P < 0.000). The subgroup analysis indicated that miRNAs in adults, serum type, downregulation of miRNA expression, criteria of Sepsis-3, internal reference of non-U6, and dysregulation expression of miR-223 had superior diagnostic accuracy. In addition, there was no significant publication bias among the included studies. Fagan’s nomogram showed valuable clinical utility.

Conclusions

Our meta-analysis indicated that the level of circulating miRNAs, particularly the miR-223, could be used as an indicator for sepsis.

Supplementary Information

Supplementary information accompanies this paper at 10.1186/s40560-020-00497-6.

Protein corona fingerprinting to differentiate sepsis from non-infectious systemic inflammation

Rapid and accurate diagnosis of sepsis remains clinically challenging. The lack of specific biomarkers that can differentiate sepsis from non-infectious systemic inflammatory diseases often leads to excessive antibiotic treatment. Novel diagnostic tests are urgently needed to rapidly and accurately diagnose sepsis and enable effective treatment. Despite investment in cutting-edge technologies available today, the discovery of disease-specific biomarkers in blood remains extremely difficult. The highly dynamic environment of plasma restricts access to vital diagnostic information that can be obtained by proteomic analysis. Here, we employed clinically used lipid-based nanoparticles (AmBisome®) as an enrichment platform to analyze the human plasma proteome in the setting of sepsis. We exploited the spontaneous interaction of plasma proteins with nanoparticles (NPs) once in contact, called the 'protein corona', to discover previously unknown disease-specific biomarkers for sepsis diagnosis. Plasma samples obtained from non-infectious acute systemic inflammation controls and sepsis patients were incubated ex vivo with AmBisome® liposomes, and the resultant protein coronas were thoroughly characterised and compared by mass spectrometry (MS)-based proteomics. Our results demonstrate that the proposed nanoparticle enrichment technology enabled the discovery of 67 potential biomarker proteins that could reproducibly differentiate non-infectious acute systemic inflammation from sepsis. This study provides proof-of-concept evidence that nanoscale-based 'omics' enrichment technologies have the potential to substantially improve plasma proteomics analysis and to uncover novel biomarkers in a challenging clinical setting.

Development of a Bioinformatics Framework for Identification and Validation of Genomic Biomarkers and Key Immunopathology Processes and Controllers in Infectious and Non-infectious Severe Inflammatory Response Syndrome

Sepsis is defined as dysregulated host response caused by systemic infection, leading to organ failure. It is a life-threatening condition, often requiring admission to an intensive care unit (ICU). The causative agents and processes involved are multifactorial but are characterized by an overarching inflammatory response, sharing elements in common with severe inflammatory response syndrome (SIRS) of non-infectious origin. Sepsis presents with a range of pathophysiological and genetic features which make clinical differentiation from SIRS very challenging. This may reflect a poor understanding of the key gene inter-activities and/or pathway associations underlying these disease processes. Improved understanding is critical for early differential recognition of sepsis and SIRS and to improve patient management and clinical outcomes. Judicious selection of gene biomarkers suitable for development of diagnostic tests/testing could make differentiation of sepsis and SIRS feasible. Here we describe a methodologic framework for the identification and validation of biomarkers in SIRS, sepsis and septic shock patients, using a 2-tier gene screening, artificial neural network (ANN) data mining technique, using previously published gene expression datasets. Eight key hub markers have been identified which may delineate distinct, core disease processes and which show potential for informing underlying immunological and pathological processes and thus patient stratification and treatment. These do not show sufficient fold change differences between the different disease states to be useful as primary diagnostic biomarkers, but are instrumental in identifying candidate pathways and other associated biomarkers for further exploration.

Medicina de precisión en sepsis: utilidad de los biomarcadores en pacientes biomarcadores en pacientes críticamente enfermos

Durante años la evolución del cuidado intensivo ha intentado ofrecer una atención basada en protocolos y paquetes de manejo agrupados por patologías y cuadro sindromáticos. Aunque se logró disminuir la mortalidad en diferentes patologías (sepsis y síndromes coronario agudo y de distrés respiratorio agudo), no se han resuelto por completo los problemas clínicos, en especial el diagnóstico y el manejo. Una nueva opción ha surgido en el horizonte denominada “medicina de precisión”, entendida como estrategia de prevención y tratamiento que tiene en cuenta la variabilidad individual. La sepsis es un síndrome con múltiples aristas en cuanto al fenotipo y genotipo, cuyo diagnóstico temprano es relevante para los desenlaces clínicos. Hasta el momento el enfoque principal ha sido la identificación de un germen etiológico para diferenciarla del síndrome de respuesta inflamatoria sistémica (SIRS). En los últimos años el paradigma en enfermedades infecciosas ha cambiado debido a estudios que demuestran como la respuesta inmunitaria del paciente séptico tiene un papel clave en el desarrollo de la enfermedad, con implicaciones en el diagnóstico, pronóstico y tratamiento, que podrían ayudar a cambiar el abordaje en los próximos años gracias a una estrategia basada en medicina de precisión. Hoy los aislamientos microbiológicos y los cultivos siguen siendo el estándar de referencia con varias desventajas como el tiempo para obtener resultados, sobre todo en infecciones por gérmenes resistentes u hongos, que pueden retrasar el inicio de la terapia antimicrobiana. Como alternativa se ha planteado el uso de biomarcadores en sepsis que siendo productos de la respuesta inflamatoria del individuo ante la infección, son útiles para el diagnóstico y pronóstico primordialmente en los críticamente enfermos. Decidimos realizar esta revisión narrativa acerca de la utilidad de los biomarcadores en pacientes con sepsis críticamente enfermos, para enfocarlos en un modelo de medicina personalizada.

Screening key genes and microRNAs in sepsis by RNA-sequencing

BACKGROUND

Sepsis is a life-threatening organ dysfunction, initiated by a dysregulated host response to infection. This study aimed to determine key genes and microRNAs (miRNAs) correlated with sepsis.

METHODS

Three patients with sepsis and three healthy individuals treated as controls were recruited in the current study. To identify differentially expressed mRNAs (DEmRNAs) and differentially expressed miRNAs (DEmiRNAs) between patients with sepsis and controls, RNA-sequencing and bioinformatics analysis were conducted. DEmiRNA-target DEmRNAs analysis and functional annotation of DEmiRNA-target DEmRNAs were performed. Dataset GSE46955, used to validate the expression of selected DEmRNAs, was downloaded from the Gene Expression Omnibus database.

RESULTS

Compared with septic patients, a total of 1199 DEmRNAs and 23 DEmiRNAs were identified. Based on DEmiRNA-target DEmRNAs analysis, hsa-miR-106b-5p (degree = 155), hsa-miR-128-3p (degree = 128), and hsa-miR-144-3p (degree = 79) were the top 3 DEmiRNAs that covered most DEmRNAs. The T cell receptor signaling pathway, pathways in cancer, FoxO signaling pathway, and influenza A were the significantly enriched Kyoto Encyclopedia of Genes and Genomes pathways of DEmiRNA-target DEmRNAs in sepsis.

CONCLUSION

We identified key genes and miRNAs related to sepsis. Our findings will provide new insights into understanding sepsis pathogenesis.

Presepsin Levels in Experimental Sepsis and Massive Bowel Resection Models in Rats

BACKGROUND/AIM

Presepsin is a useful biomarker for diagnosing sepsis. This study aimed to investigate the relationship between oxidative stress and presepsin levels in animal models.

MATERIALS AND METHODS

Sprague-Dawley rats were used for cecal ligation and puncture (CLP) and to generate massive bowel resection (MBR) models. Trunk blood was collected for analysis of presepsin. Liver and intestinal tissue samples were taken to determine oxidative stress parameters.

RESULTS

Presepsin levels in MBR and CLP sepsis models were higher than those in control groups. Reactive oxygen and nitrogen species (RONS) and malondialdehyde levels were increased in the liver and small intestine of rats in both models, whereas glutathione levels were decreased.

CONCLUSION

Presepsin levels and RONS may be released by the same mechanism which is closely associated with the progression of sepsis and inflammation in both CLP and MBR models.

MicroRNA-495 serves as a diagnostic biomarker in patients with sepsis and regulates sepsis-induced inflammation and cardiac dysfunction

BACKGROUND

Sepsis leads to severe inflammatory and cardiac dysfunction. This study aimed to explore the clinical value of miR-495 in sepsis, as well as its role in sepsis-induced inflammation and cardiac dysfunction.

METHODS

105 sepsis patients were recruited; receiver operating characteristic (ROC) curve was plotted to assess the diagnostic value of miR-495 in sepsis. A model of sepsis in rats was created via performing cecal ligation and puncture (CLP). After modeling, the cardiac function, including left ventricular systolic pressure (LVSP), left ventricular end diastolic pressure (LVEDP) and maximum rate of rise/fall of left ventricle pressure (± dp/dtmax), and serum cardiac troponin I (CTn-I), creative kinase isoenzyme MB (CK-MB) were detected. The blood cytokines levels including TNF-α, IL-6, IL-1β were also measured. Quantitative real-time PCR (qRT-PCR) was used for the measurement of the expression level of miR-495.

RESULTS

MiR-495 was significantly downregulated in sepsis patients, especially patients who suffered from septic shock (SS). MiR-495 expression was negatively associated with Scr, WBC, CRP, PCT, APACHE II score and SOFA score. MiR-495 could distinguish patients with SS from non-SS patients. MiR-495 and SOFA score were better indictors for the occurrence of cardiac dysfunction in sepsis patients. In CLP-induced sepsis model. CLP rats experienced deterioration of LVSP, LVEDP, ± dp/dtmax, and had a rise in serum CTn-I, CK-MB, TNF-α, IL-6 and IL-1β, which were improved by miR-495 agomir injection.

CONCLUSIONS

MiR-495 might be a potential diagnostic biomarker for sepsis patients, and overexpression of miR-495 alleviated sepsis-induced inflammation and cardiac dysfunction.

Potential role of circulating long noncoding RNA MALAT1 in predicting disease risk, severity, and patients' survival in sepsis

Background

This study aimed to investigate the plasma long noncoding RNA metastasis‐associated lung adenocarcinoma transcript 1 (lncRNA MALAT1) expression with risk, severity, inflammation level, and prognosis in sepsis.

Methods

One hundred and ninety sepsis patients and 190 health controls (HCs) were consecutively recruited. Blood samples within 24 hours after admission of sepsis patients and those on enrollment of HCs were collected, and then, plasma was separated for lncRNA MALAT1 and miR‐125b expressions detections by RT‐qPCR. In sepsis patients, clinical data and 28‐day mortality were recorded, and plasma inflammatory cytokines expressions were detected by ELISA.

Results

Plasma lncRNA MALAT1 expression was elevated in sepsis patients than HCs (P < 0.001), and ROC curve disclosed that it had a good value in predicting sepsis risk with an area under curve (AUC) of 0.823 (95% CI: 0.783‐0.864). Additionally, lncRNA MALAT1 expression was positively correlated with Scr (P = 0.005), WBC (P = 0.017), CRP (P < 0.001), PCT (P < 0.001), TNF‐α (P < 0.001), IL‐8 (P < 0.001), IL‐17 (P = 0.001), APACHE II score (P < 0.001), and SOFA score (P < 0.001). LncRNA MALA1 expression was elevated in deaths compared with survivors (P < 0.001) and could predict the risk of 28‐day mortality with an AUC of 0.755 (95% CI: 0.682‐0.828). Accumulating survival was worse in patients with lncRNA MALAT1 high expression compared with patients who had lncRNA MALAT1 low expression (P < 0.001). Moreover, lncRNA MALAT1 expression was negatively correlated with miR‐125b level in both sepsis patients (P < 0.001) and HCs (P < 0.001).

Conclusion

LncRNA MALAT1 could be developed as a potential biomarker for facilitating diagnosis and management in sepsis patients.

Biomarkers for Infection in Children: Current Clinical Practice and Future Perspectives

Biomarkers have become an integral part of the clinical decision-making process of clinicians dealing with febrile children. C-reactive protein, procalcitonin and white blood cell count are probably the most studied ones. Crucial to using biomarkers is the understanding of how a test result will alter post-test probabilities and then impact on clinical decision making. Improved analytical and computational platforms have enabled the next generation of advanced biomarker discovery studies. Promising combinations of candidate biomarkers for a diverse spectrum of febrile illnesses, such as viral and bacterial infections, have been identified using proteomics, RNA gene expression and metabolomics.

Biomarkers in Pneumonia-Beyond Procalcitonin

Pneumonia is the leading infectious cause of mortality worldwide and one of the most common lower respiratory tract infections that is contributing significantly to the burden of antibiotic consumption. Due to the complexity of its pathophysiology, it is widely accepted that clinical diagnosis and prognosis are inadequate for the accurate assessment of the severity of the disease. The most challenging task for a physician is the risk stratification of patients with community-acquired pneumonia. Herein, early diagnosis is essential in order to reduce hospitalization and mortality. Procalcitonin and C-reactive protein remain the most widely used biomarkers, while interleukin 6 has been of particular interest in the literature. However, none of them appear to be ideal, and the search for novel biomarkers that will most sufficiently predict the severity and treatment response in pneumonia has lately intensified. Although our insight has significantly increased over the last years, a translational approach with the application of genomics, metabolomics, microbiomics, and proteomics is required to better understand the disease. In this review, we discuss this rapidly evolving area and summarize the application of novel biomarkers that appear to be promising for the accurate diagnosis and risk stratification of pneumonia.

A Comparative Review of Equine SIRS, Sepsis, and Neutrophils

The most recent definition of sepsis in human medicine can be summarized as organ dysfunction caused by a dysregulated host response to infection. In equine medicine, although no consensus definition is available, sepsis is commonly described as a dysregulated host systemic inflammatory response to infection. Defense against host infection is the primary role of innate immune cells known as neutrophils. Neutrophils also contribute to host injury during sepsis, making them important potential targets for sepsis prevention, diagnosis, and treatment. This review will present both historical and updated perspectives on the systemic inflammatory response (SIRS) and sepsis; it will also discuss the impact of sepsis on neutrophils, and the impact of neutrophils during sepsis. Future identification of clinically relevant sepsis diagnosis and therapy depends on a more thorough understanding of disease pathogenesis across species. To gain this understanding, there is a critical need for research that utilizes a clearly defined, and consistently applied, classification system for patients diagnosed with, and at risk of developing, sepsis.

Inflammation and Depression: A Nervous Plea for Psychiatry to Not Become Immune to Interpretation

The possibility that inflammation plays a causal role in major depression is an important claim in the emerging field of immunopsychiatry and has generated hope for new treatments. The aims of the present review are first to provide some historical background and to consider the evidence in favor of the claim that inflammation is causally involved in major depression. The second part discusses some of the possibilities allowed for by the use of broad 'umbrella' concepts, such as inflammation and stress, in terms of proposing new working hypotheses and potential mechanisms. The third part reviews proposed biomarkers of inflammation and depression and the final part addresses how elements discussed in the preceding sections are used in immunopsychiatry. The 'umbrella' concepts of inflammation and stress, as well as insufficiently-met criteria based inferences and reverse inferences are being used to some extent in immunopsychiatry. The field is therefore encouraged to specify concepts and constructs, as well as to consider potential alternative interpretations and explanations for findings obtained. The hope is that pointing out some of the potential problems will allow for a clearer picture of immunopsychiatry's current strengths and limitations and help the field mature.

Influence of Orexinergic System on Survival in Septic Rats

BACKGROUND

The orexinergic (OXergic) system contributes to the defense system. It has also been reported that the degeneration of OXergic neurons occurs during sepsis. Thus, the decline of OXergic activity may contribute to impairment of the defense system in sepsis. In this study, we determined whether: (i) lipopolysaccharide (LPS) reduces the brain orexin A (OXA) content and (ii) the OXergic system contributes to survival from sepsis in rats.

METHODS

With approval of our protocol by our University Animal Ethics Committee, OX neuron-ablated (OX/ataxin-3 transgenic [OX/AT3 TG]) and wild-type Sprague-Dawley rats, weighing 250-350 g, were used. LPS (10 mg/kg) was administered intraperitonally to the wild-type rats (group SD, n = 26) and OX/AT3 TG rats (group TG, n = 14). Another 7 SD rats were included as a saline control (group C). Survival analysis was then performed over a period of 3 days. All surviving rats were decapitated and the brain OXA contents (from the cerebrocortex, hippocampus, hypothalamus, and pons) were quantified using ELISA kits.

RESULTS

In group SD, 61.5% rats survived, while in group TG, only 21.4% survived (p < 0.05). LPS significantly reduced OXA content (pg/mg of tissue) in group SD (2.92 ± 0.38) compared to in group C (4.10 ± 1.21) in the pons (p < 0.05). OXA content in group TG was substantially lower than in group C and group SD in all brain regions.

CONCLUSIONS

LPS significantly reduced OXA contents in the pons which contains the locus coeruleus to regulate sympathetic activity in the defense system.

Using Procalcitonin in Septic Shock to Guide Antibacterial Therapy

Over the last decade, the biomarkers procalcitonin and C-reactive protein have gained interest in sepsis research. Procalcitonin is a unique biomarker that is specific to bacterial infection and has demonstrated utility in the risk stratification of patients with potential life-threatening bacterial infections. In addition, procalcitonin has been documented as having a role in reducing the rate of unnecessary antibiotics while positively impacting antibiotic resistance rates and cost savings. The purposes of this review article are to discuss the clinical relevance of C-reactive protein and procalcitonin as diagnostic and prognostic markers for sepsis with a focus on the use of serial procalcitonin levels as a component of antibiotic stewardship programs. The federal government has recently become invested in combating the progression of antibiotic resistance; a 5-year national plan has been developed to address these concerns. Establishing a reliable antibiotic stewardship program is one of the goals of this national plan.

Predictors of treatment failure and clinical stability in patients with community acquired pneumonia

Community acquired pneumonia (CAP) is the leading infectious cause of mortality worldwide with approximately 10% of patients hospitalized requiring intensive care unit (ICU) admission. The ability to predict clinical stability (CS) and treatment failure (TF) enables the clinician to alter antibiotics appropriately, facilitate a timely ICU admission, or arrange a suitable discharge. The detection of CS and TF can be difficult and changes in clinical signs may be subtle or delayed. Thus clinical scores and biomarkers are routinely used to identify severity and monitor clinical progression. The evidence, however, is vast and the definitive role of these systems is at times difficult to elucidate. The aim of this review is to analyse the current literature and to provide a rational and clinically focused view of the predictive utility of various systems used to identify CS and TF in CAP.

Non-coding RNA: a potential biomarker and therapeutic target for sepsis

Sepsis, a syndrome of physiologic, pathologic, and biochemical abnormalities caused by an altered systemic host response to infection, has become the main cause of death among patients admitted to the intensive care units. Recently, genome-wide expression analysis revealed that over 80% of the essential genetic elements were altered in critically ill patients. Notably, non-coding RNAs, including microRNAs, long non-coding RNAs and circular RNAs, have been proven to play essential roles in innate immunity, mitochondrial dysfunction and organ dysfunction. In this review, we introduced the biogenesis of non-coding RNAs briefly and summed up different kinds of non-coding RNAs in regulation of sepsis, which could provide a more comprehensive understanding about pathogenesis of the disease. Additionally, we summarized the limitations of current biomarkers and then recommended some non-coding RNAs as novel potential biomarkers for sepsis and sepsis-induced organ dysfunction. Besides, we also introduced some problems and challenges that need to be overcome during the clinical application of non-coding RNAs. Future research should focus on elucidating their molecular mechanisms, particularly long non-coding RNAs as well as circular RNAs and sepsis, to further understanding of the disease process. With the in-depth understanding of the mechanism of sepsis, non-coding RNAs provide a new insight into sepsis and could become the novel therapeutic targets in the future.

Diagnostic accuracy of procalcitonin, neutrophil-lymphocyte count ratio, C-reactive protein, and lactate in patients with suspected bacterial sepsis

Background

Early recognition is a key factor to achieve improved outcomes for septic patients. Combinations of biomarkers, as opposed to single ones, may improve timely diagnosis and survival. We investigated the performance characteristics of sepsis biomarkers, alone and in combination, for diagnosis of verified bacterial sepsis using Sepsis-2 and Sepsis-3 criteria, respectively.

Methods

Procalcitonin (PCT), neutrophil-lymphocyte count ratio (NLCR), C-reactive protein (CRP), and lactate were determined in a total of 1,572 episodes of adult patients admitted to the emergency department on suspicion of sepsis. All sampling were performed prior to antibiotic administration. Discriminant analysis was used to construct two composite biomarkers consisting of linear combinations of the investigated biomarkers, one including three selected biomarkers (i.e., NLCR, CRP, and lactate), and another including all four (i.e., PCT, NLCR, CRP, and lactate). The diagnostic performances of the composite biomarkers as well as the individual biomarkers were compared using the area under the receiver operating characteristic curve (AUC).

Results

For diagnosis of bacterial sepsis based on Sepsis-3 criteria, the AUC for PCT (0.68; 95% CI 0.65–0.71) was comparable to the AUCs for the both composite biomarkers. Using the Sepsis-2 criteria for bacterial sepsis diagnosis, the AUC for the NLCR (0.68; 95% CI 0.65–0.71) but not for the other single biomarkers, was equal to the AUCs for the both composite biomarkers. For diagnosis of severe bacterial sepsis or septic shock based on the Sepsis-2 criteria, the AUCs for both composite biomarkers were significantly greater than those of the single biomarkers (0.85; 95% CI 0.82–0.88 for the composite three-biomarker, and 0.86; 95% CI 0.83–0.89 for the composite four-biomarker).

Conclusions

Combinations of biomarkers can improve the diagnosis of verified bacterial sepsis in the most critically ill patients, but in less severe septic conditions either the NLCR or PCT alone exhibit equivalent performance.

The role of group IIA secretory phospholipase A2 (sPLA2-IIA) as a biomarker for the diagnosis of sepsis and bacterial infection in adults-A systematic review

INTRODUCTION

This paper investigates the role of Group II Secretory Phospholipase A2 (sPLA2-IIA) as a biomarker for the diagnosis of sepsis and bacterial infection in adults. Sepsis and bacterial infection are common problems encountered by patients in the hospital and often carry adverse outcomes if not managed early.

METHODS

Two independent reviewers conducted a comprehensive search using Ovid MEDLINE published from years 1993 to 2016 and SCOPUS published from year 1985 to 2017 to screen for relevant studies. The main inclusion criteria included adult subjects, patients with suspected or confirmed signs of infection and relevant outcomes which looked into the role of sPLA2-IIA in detecting the presence of sepsis and bacterial infection in the subjects.

RESULTS AND DISCUSSION

Four studies met the inclusion criteria. SPLA2-IIA was found to be effective in detecting the presence of sepsis and bacterial infection in adults. The levels of serum sPLA2-IIA also correlated well with the presence of sepsis and bacterial infection.

CONCLUSION

This systematic review highlights the role of sPLA2-IIA as a reliable tool to diagnose sepsis and bacterial infection in adult patients. Nonetheless, further studies should be done in the future to provide more compelling evidence on its application in the clinical setting.

Use of presepsin and procalcitonin for prediction of SeptiFast results in critically ill patients

PURPOSE

There is a need for identification of marker that could lead physicians to take the right step towards laboratory techniques for documentation of infection. The aim of this study was to investigate whether presepsin and procalcitonin (PCT) levels in patients with suspected sepsis could predict blood culture (BC) and SeptiFast (SF) results.

MATERIAL AND METHODS

100 patients were included in our study. PCT, C-reactive protein (CRP), and presepsin levels were determined. Differences between groups of patients were assessed by Mann-Whitney U test. Categorical variables were compared using chi-square test. Receiver operating characteristic (ROC) curves were plotted to determine predictive values of biomarkers for prediction of positive SF results.

RESULTS

PCT (70.9±106.36 vs. 16.35±26.79) and presepsin (4899.73±5207.81 vs. 1751.59±2830.62) were significantly higher in patients with positive SF in contrast to patients with negative SF. There was no significant difference between patients who had positive and negative BC for PCT and presepsin values. PCT and presepsin showed a similar performance in predicting positive SF results with AUC of 0.75 for PCT and 0.73 for presepsin.

CONCLUSION

Presepsin can serve as good predictor of bacteremia detected by SF and it should be included with PCT in protocols for sepsis diagnosing.

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

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

Tools for outcome prediction in patients with community acquired pneumonia

INTRODUCTION

Community-acquired pneumonia (CAP) is one of the most common causes of mortality world-wide. The mortality rate of patients with CAP is influenced by the severity of the disease, treatment failure and the requirement for hospitalization and/or intensive care unit (ICU) management, all of which may be predicted by biomarkers and clinical scoring systems. Areas covered: We review the recent literature examining the efficacy of established and newly-developed clinical scores, biological and inflammatory markers such as C-Reactive protein (CRP), procalcitonin (PCT) and Interleukin-6 (IL-6), whether used alone or in conjunction with clinical severity scores to assess the severity of CAP, predict treatment failure, guide acute in-hospital or ICU admission and predict mortality. Expert commentary: The early prediction of treatment failure using clinical scores and biomarkers plays a developing role in improving survival of patients with CAP by identifying high-risk patients requiring hospitalization or ICU admission; and may enable more efficient allocation of resources. However, it is likely that combinations of scoring systems and biomarkers will be of greater use than individual markers. Further larger studies are needed to corroborate the additive value of these markers to clinical prediction scores to provide a safer and more effective assessment tool for clinicians.

Clinical value of alkaline phosphatase on the surface membrane of neutrophils for prediction of bacteremia in patients with systemic inflammatory response syndrome

In this study, the utility and diagnostic accuracy of alkaline phosphatase on the surface membrane of neutrophils (mNAP) for bacteremia in patients with systemic inflammatory response syndrome (SIRS) was investigated and assessed. A total of 149 patients with SIRS were included. mNAP values were significantly higher in bacteremic SIRS group compared with that in non-bacteremic SIRS group (P < 0.001). The mNAP levels were significantly higher in SIRS patients with gram-negative bacteremia than those with gram-positive bacteremia. (P < 0.001). The receiver operating characteristic (ROC) curve analysis revealed the areas under ROC (AUC) of 0.806 for mNAP in differentiating SIRS patients with bacteremia from those without, similar to that for procalcitonin (PCT) (0.797). Combination of PCT and mNAP gave an AUC of 0.841. mNAP shares a similar diagnostic accuracy to PCT in predicting bacteremia in SIRS patients. The combination of mNAP and PCT provides a better prediction of bacteremia in patients with SIRS than either test alone.

Mechanisms of decompensation and organ failure in cirrhosis: From peripheral arterial vasodilation to systemic inflammation hypothesis

The peripheral arterial vasodilation hypothesis has been most influential in the field of cirrhosis and its complications. It has given rise to hundreds of pathophysiological studies in experimental and human cirrhosis and is the theoretical basis of life-saving treatments. It is undisputed that splanchnic arterial vasodilation contributes to portal hypertension and is the basis for manifestations such as ascites and hepatorenal syndrome, but the body of research generated by the hypothesis has revealed gaps in the original pathophysiological interpretation of these complications. The expansion of our knowledge on the mechanisms regulating vascular tone, inflammation and the host-microbiota interaction require a broader approach to advanced cirrhosis encompassing the whole spectrum of its manifestations. Indeed, multiorgan dysfunction and failure likely result from a complex interplay where the systemic spread of bacterial products represents the primary event. The consequent activation of the host innate immune response triggers endothelial molecular mechanisms responsible for arterial vasodilation, and also jeopardizes organ integrity with a storm of pro-inflammatory cytokines and reactive oxygen and nitrogen species. Thus, the picture of advanced cirrhosis could be seen as the result of an inflammatory syndrome in contradiction with a simple hemodynamic disturbance.

Biomarkers in infection and sepsis: Can they really indicate final outcome?

Infectious diseases are among the most common reasons for admission to hospital and can easily lead to sepsis. Sepsis is globally associated with increased mortality, and although biomarkers could help clinicians in the early diagnosis of sepsis and immediate onset of antibiotics, there are always questions to be answered about their usefulness in the prognosis of infectious diseases. This article reviews some of the available biomarkers used in infectious diseases and sepsis in order to evaluate their utility to predict mortality and unfavourable outcome. Several studies present the pros and cons of each compound, but it is obvious that the ideal biomarker, with high sensitivity and specificity, cost effectiveness and with definite cut-off ranges and time of blood sampling, is yet to be found.

Hydrogen gas inhibits high-mobility group box 1 release in septic mice by upregulation of heme oxygenase 1

BACKGROUND

Sepsis is a potentially fatal whole-body inflammation caused by severe infection. Hydrogen gas (H2) is effective for treating sepsis. In this study, we hypothesized that the protective function of H2 in mice with septic lung injury occurred through the activation of heme oxygenase 1 (HO-1) and its upstream regulator nuclear factor-erythroid 2 p45-related factor 2 (Nrf2).

MATERIALS AND METHODS

Male institute of cancer research mice were subjected to sepsis by cecal ligation and puncture (CLP) with the presence or absence of H2. Beginning at 1 and 6 h after CLP or sham operation, respectively, 2% H2 was inhaled for 1 h. We intraperitoneally injected the HO-1 inhibitor zinc protoporphyrin IX (40 mg/kg) 1 h before CLP. To assess the severity of septic lung injury, we observed the 7-d survival rate, wet/dry weight ratio of lung, lung histopathologic score, oxygenation index, and so forth. Serum and homogenates from the lung, liver, and kidney were acquired for measuring the levels of high-mobility group box 1 (HMGB1) at 6, 12, and 24 h after CLP or sham operation. Furthermore, the protein and messenger RNA expression of Nrf2, HO-1, and HMGB1 was measured at 6, 12, and 24 h.

RESULTS

Septic mice had a lower survival rate and more severe lung injury compared with the sham group. However, therapy with H2 increased the survival rate and alleviated the severity of lung injury, reduced the HMGB1 level, and increased the HO-1 and Nrf2 levels in septic mice. Moreover, the HO-1 inhibitor zinc protoporphyrin IX significantly eliminated the protective effect of H2 on septic lung injury.

CONCLUSIONS

H2 plays a significant role in regulating the release of the inflammatory cytokine HMGB1 in septic mice, which is partially mediated through the activation of HO-1 as a downstream molecule of Nrf2.

Sepsis Pathogen Identification

Sepsis is a rapidly progressing, severe inflammatory response to infection, causing more than 200,000 deaths per year. Rapid, specific pathogen identification is important to guide sepsis treatment. In this review, we describe and compare currently available commercial products for sepsis diagnosis and pathogen identification, based on microbiological, molecular, and mass spectrometric technologies. Microbiological techniques, the current "gold standard" in sepsis pathogen identification, include blood culture followed by subculturing and pathogen identification via biochemical or microscopic means. These methods have been automated but nevertheless require several days to generate results. Alternative technologies, including highly multiplexed PCR-based methods and mass spectrometric approaches, can decrease the required turnaround time. Matrix-assisted laser-desorption ionization time-of-flight-based systems have recently become an attractive option to rapidly identify a broad spectrum of sepsis pathogens with good sensitivity and specificity. Effectively integrating rapid sepsis pathogen identification into the hospital workflow can improve patient outcomes and can reduce the length of hospitalization and cost per patient.

Volatile Organic Compounds during Inflammation and Sepsis in Rats

Background:

Multicapillary column ion-mobility spectrometry (MCC-IMS) may identify volatile components in exhaled gas. The authors therefore used MCC-IMS to evaluate exhaled gas in a rat model of sepsis, inflammation, and hemorrhagic shock.

Methods:

Male Sprague–Dawley rats were anesthetized and ventilated via tracheostomy for 10 h or until death. Sepsis was induced by cecal ligation and incision in 10 rats; a sham operation was performed in 10 others. In 10 other rats, endotoxemia was induced by intravenous administration of 10 mg/kg lipopolysaccharide. In a final 10 rats, hemorrhagic shock was induced to a mean arterial pressure of 35 ± 5 mmHg. Exhaled gas was analyzed with MCC-IMS, and volatile compounds were identified using the BS-MCC/IMS-analytes database (Version 1209; B&S Analytik, Dortmund, Germany).

Results:

All sham animals survived the observation period, whereas mean survival time was 7.9 h in the septic animals, 9.1 h in endotoxemic animals, and 2.5 h in hemorrhagic shock. Volatile compounds showed statistically significant differences in septic and endotoxemic rats compared with sham rats for 3-pentanone and acetone. Endotoxic rats differed significantly from sham for 1-propanol, butanal, acetophenone, 1,2-butandiol, and 2-hexanone. Statistically significant differences were observed between septic and endotoxemic rats for butanal, 3-pentanone, and 2-hexanone. 2-Hexanone differed from all other groups in the rats with shock.

Conclusions:

Breath analysis of expired organic compounds differed significantly in septic, inflammation, and sham rats. MCC-IMS of exhaled breath deserves additional study as a noninvasive approach for distinguishing sepsis from inflammation.

Heterogeneous models for an early discrimination between sepsis and non-infective SIRS in medical ward patients: a pilot study

The objective of the study was to determine the accuracy of phospholipase A2 group II (PLA2-II), interferon-gamma-inducible protein 10 (IP-10), angiopoietin-2 (Ang-2), and procalcitonin (PCT) plasma levels in early ruling in/out of sepsis among systemic inflammatory response syndrome (SIRS) patients. Biomarker levels were determined in 80 SIRS patients during the first 4 h of admission to the medical ward. The final diagnosis of sepsis or non-infective SIRS was issued according to good clinical practice. Sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) for sepsis diagnosis were assessed. The optimal biomarker combinations with clinical variables were investigated by logistic regression and decision tree (CART). PLA2-II, IP-10 and PCT, but not Ang-2, were significantly higher in septic (n = 60) than in non-infective SIRS (n = 20) patients (P ≤ 0.001, 0.027, and 0.002, respectively). PLA2-II PPV and NPV were 88 and 86%, respectively. The corresponding figures were 100 and 31% for IP-10, and 93 and 35% for PCT. Binary logistic regression model had 100% PPV and NPV, while manual and software-generated CART reached an overall accuracy of 95 and 98%, respectively, both with 100% NPV. PLA2-II and IP-10 associated with clinical variables in regression or decision tree heterogeneous models may be valuable biomarkers for sepsis diagnosis in SIRS patients admitted to medical ward (MW). Further studies are needed to introduce them into clinical practice.

Markers for sepsis diagnosis in the forensic setting: state of the art

Reliable diagnoses of sepsis remain challenging in forensic pathology routine despite improved methods of sample collection and extensive biochemical and immunohistochemical investigations. Macroscopic findings may be elusive and have an infectious or non-infectious origin. Blood culture results can be difficult to interpret due to postmortem contamination or bacterial translocation. Lastly, peripheral and cardiac blood may be unavailable during autopsy. Procalcitonin, C-reactive protein, and interleukin-6 can be measured in biological fluids collected during autopsy and may be used as in clinical practice for diagnostic purposes. However, concentrations of these parameters may be increased due to etiologies other than bacterial infections, indicating that a combination of biomarkers could more effectively discriminate non-infectious from infectious inflammations. In this article, we propose a review of the literature pertaining to the diagnostic performance of classical and novel biomarkers of inflammation and bacterial infection in the forensic setting.

Energy crisis: the role of oxidative phosphorylation in acute inflammation and sepsis

Mitochondrial dysfunction is increasingly recognized as an accomplice in most of the common human diseases including cancer, neurodegeneration, diabetes, ischemia/reperfusion injury as seen in myocardial infarction and stroke, and sepsis. Inflammatory conditions, both acute and chronic, have recently been shown to affect mitochondrial function. We here discuss the role of oxidative phosphorylation (OxPhos), focusing on acute inflammatory conditions, in particular sepsis and experimental sepsis models. We discuss mitochondrial alterations, specifically the suppression of oxidative metabolism and the role of mitochondrial reactive oxygen species in disease pathology. Several signaling pathways including metabolic, proliferative, and cytokine signaling affect mitochondrial function and appear to be important in inflammatory disease conditions. Cytochrome c oxidase (COX) and cytochrome c, the latter of which plays a central role in apoptosis in addition to mitochondrial respiration, serve as examples for the entire OxPhos system since they have been studied in more detail with respect to cell signaling. We propose a model in which inflammatory signaling leads to changes in the phosphorylation state of mitochondrial proteins, including Tyr304 phosphorylation of COX catalytic subunit I. This results in an inhibition of OxPhos, a reduction of the mitochondrial membrane potential, and consequently a lack of energy, which can cause organ failure and death as seen in septic patients.

Sepsis outside intensive care unit: the other side of the coin

INTRODUCTION

A growing body of evidence points out that a large amount of patients with sepsis are admitted and treated in medical ward (MW). With most of the sepsis studies conducted in intensive care unit (ICU), these patients, older and with more comorbidities have received poor attention. Provided the differences between the two groups of patients, results of diagnostic and therapeutic trials from ICU should not be routinely transferred to MW, where sepsis seems to be at least as common as in ICU.

METHODS

We analyzed clinical trials on novel tools for an early diagnosis of sepsis published in the last two year adopting strict research criteria. Moreover we conducted a target review of the literature on non-invasive monitoring of severe sepsis and septic shock.

RESULTS AND CONCLUSIONS

The combination of innovative and non-invasive tools for sepsis rule in/out, as quick alternatives to blood cultures (gold standard) with bedside integrated ultrasonography could impact triage, diagnosis and prognosis of septic patients managed in MW, preventing ICU admissions, poor outcomes and costly complications, especially in elderly that are usually highly vulnerable to invasive procedures.

Role of extracellular and intracellular microRNAs in sepsis

Sepsis is the major cause of death in the intensive care unit (ICU). Numerous biomarkers have been studied to identify the cause and severity of sepsis but these factors cannot differentiate between infectious and non-infectious inflammatory response. MicroRNAs (miRNAs) are non-coding RNA transcripts that regulate the expression of genes by repressing translation or degrading mRNA. Importantly, miRNAs can be released outside cells and easily detectable in bodily fluids such as blood, sweat, urine and breast milk. Numerous studies have explored the idea of utilizing extracellular miRNAs as biomarkers for sepsis by profiling the dysregulation of miRNAs in blood samples of sepsis patients. So far, miR-223, miR-146a and miR-150 have been identified to have promising prognostic and diagnostic value to sepsis. In addition, various intracellular miRNAs have been implicated to play critical roles in regulating the TLR-NF-κB pathway, which is a well-known inflammatory signaling pathway involved in the process of sepsis. Here, we summarize the recent progress on the role of extracellular and intracellular miRNAs in sepsis. Specifically, we discuss the possible role of circulating miRNA biomarkers for the diagnosis of sepsis and how intracellular miRNAs regulate the inflammatory responses in sepsis.

Leptin fails to blunt the lipopolysaccharide-induced activation of the hypothalamic-pituitary-adrenal axis in rats

Obesity is a risk factor for sepsis morbidity and mortality, whereas the hypothalamic-pituitary-adrenal (HPA) axis plays a protective role in the body's defence against sepsis. Sepsis induces a profound systemic immune response and cytokines serve as excellent markers for sepsis as they act as mediators of the immune response. Evidence suggests that the adipokine leptin may play a pathogenic role in sepsis. Mouse endotoxaemic models present with elevated leptin levels and exogenously added leptin increased mortality whereas human septic patients have elevated circulating levels of the soluble leptin receptor (Ob-Re). Evidence suggests that leptin can inhibit the regulation of the HPA axis. Thus, leptin may suppress the HPA axis, impairing its protective role in sepsis. We hypothesised that leptin would attenuate the HPA axis response to sepsis. We investigated the direct effects of an i.p. injection of 2 mg/kg leptin on the HPA axis response to intraperitoneally injected 25 μg/kg lipopolysaccharide (LPS) in the male Wistar rat. We found that LPS potently activated the HPA axis, as shown by significantly increased plasma stress hormones, ACTH and corticosterone, and increased plasma interleukin 1β (IL1β) levels, 2 h after administration. Pre-treatment with leptin, 2 h before LPS administration, did not influence the HPA axis response to LPS. In turn, LPS did not affect plasma leptin levels. Our findings suggest that leptin does not influence HPA function or IL1β secretion in a rat model of LPS-induced sepsis, and thus that leptin is unlikely to be involved in the acute-phase endocrine response to bacterial infection in rats.

Possible implication of bacterial infection in acute graft-versus-host disease after allogeneic hematopoietic stem cell transplantation

Graft-versus-host disease (GVHD) is still one of the major causes of morbidity and mortality in allogeneic hematopoietic stem cell transplantation (HSCT). In the pathogenesis of acute GVHD, it has been established that donor-derived T-cells activated in the recipient play a major role in GVHD in initiation and maintenance within an inflammatory cascade. To reduce the risk of GVHD, intensification of GVHD prophylaxis like T-cell depletion is effective, but it inevitably increases the risk of infectious diseases and abrogates beneficial graft-versus-leukemia effects. Although various cytokines are considered to play an important role in the pathogenesis of GVHD, GVHD initiation is such a complex process that cannot be prevented by means of single inflammatory cytokine inhibition. Thus, efficient methods to control the whole inflammatory milieu both on cellular and humoral view are needed. In this context, infectious diseases can theoretically contribute to an elevation of inflammatory cytokines after allogeneic HSCT and activation of various subtypes of immune effector cells, which might in summary lead to an aggravation of acute GVHD. The appropriate treatments or prophylaxis of bacterial infection during the early phase after allogeneic HSCT might be beneficial to reduce not only infectious-related but also GVHD-related mortality. Here, we aim to review the literature addressing the interactions of bacterial infections and GVHD after allogeneic HSCT.