Serum lipopolysaccharide binding protein levels predict severity of lung injury and mortality in patients with severe sepsis

Endothelial cell dynamics in sepsis-induced acute lung injury and acute respiratory distress syndrome: pathogenesis and therapeutic implications

Sepsis, a prevalent critical condition in clinics, continues to be the leading cause of death from infections and a global healthcare issue. Among the organs susceptible to the harmful effects of sepsis, the lungs are notably the most frequently affected. Consequently, patients with sepsis are predisposed to developing acute lung injury (ALI), and in severe cases, acute respiratory distress syndrome (ARDS). Nevertheless, the precise mechanisms associated with the onset of ALI/ARDS remain elusive. In recent years, there has been a growing emphasis on the role of endothelial cells (ECs), a cell type integral to lung barrier function, and their interactions with various stromal cells in sepsis-induced ALI/ARDS. In this comprehensive review, we summarize the involvement of endothelial cells and their intricate interplay with immune cells and stromal cells, including pulmonary epithelial cells and fibroblasts, in the pathogenesis of sepsis-induced ALI/ARDS, with particular emphasis placed on discussing the several pivotal pathways implicated in this process. Furthermore, we discuss the potential therapeutic interventions for modulating the functions of endothelial cells, their interactions with immune cells and stromal cells, and relevant pathways associated with ALI/ARDS to present a potential therapeutic strategy for managing sepsis and sepsis-induced ALI/ARDS.

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.

Coronin-1A serves as a serum biomarker for supportive diagnosis of Mycobacterium tuberculosis infection

Introduction

The severity and spread of tuberculosis, a major burden, can be prevented by more rapid and accurate laboratory diagnosis. The purpose of this study is to systematically explore candidate serum proteins in patients with Mycobacterium tuberculosis infection for further application as novel biomarkers.

Methods

Our study was performed in two major steps: screening of the literature for potential biomarkers, and then validation of their levels in patients and controls. Many serum/plasma proteins previously reported to be abnormally expressed in patients with tuberculosis between 2012 and 2021 were comprehensively assembled. The biological role in tuberculosis was also predicted for each using the bioinformatics tool STRING. Candidate proteins found to have the same expression in other related diseases were excluded. Subsequently, the serum level of the candidate serum/plasma protein that met the aforementioned criteria was validated by sandwich ELISA; diagnostic performance was analysed by the area under the curve (AUC) of the receiver operating characteristic (ROC).

Results

From 103 collected serum/plasma proteins, coronin-1A was found to have abnormal expression only in patients with tuberculosis and was associated with tuberculosis. In addition, the validation of coronin-1A in the serum of patients with pulmonary tuberculosis revealed a higher level than in that of healthy individuals. Furthermore, the area under the ROC curve for diagnostic power of coronin-1A was 0.866, with high sensitivity and specificity at a cut-point of approximately 52.7 ng/mL.

Conclusions

We concluded that the level of serum coronin-1A might serve as a novel biomarker for alternative laboratory examination to effectively distinguish patients with tuberculosis from those with other related diseases and healthy individuals.

Oral and Intestinal Bacterial Substances Associated with Disease Activities in Patients with Rheumatoid Arthritis: A Cross-Sectional Clinical Study

Intestinal bacterial compositions of rheumatoid arthritis (RA) patients have been reported to be different from those of healthy people. Dysbiosis, imbalance of the microbiota, is widely known to cause gut barrier damage, resulting in an influx of bacteria and their substances into host bloodstreams in animal studies. However, few studies have investigated the effect of bacterial substances on the pathophysiology of RA. In this study, eighty-seven active RA patients who had inadequate responses to conventional synthetic disease-modifying antirheumatic drugs or severe comorbidities were analyzed for correlations between many factors such as disease activities, disease biomarkers, intestinal bacterial counts, fecal and serum lipopolysaccharide (LPS), LPS-binding protein (LBP), endotoxin neutralizing capacity (ENC), and serum antibacterial substance IgG and IgA antibody levels by multiple regression analysis with consideration for demographic factors such as age, sex, smoking, and methotrexate treatment. Serum LBP levels, fecal LPS levels, total bacteria counts, serum anti-LPS from Porphyromonas gingivalis (Pg-LPS) IgG antibody levels, and serum anti-Pg-LPS IgA antibody levels were selected for multiple regression analysis using Spearman’s correlation analysis. Serum LBP levels were correlated with disease biomarker levels, such as erythrocyte sedimentation rate ( $p<0.001$ ), C-reactive protein ( $p<0.001$ ), matrix metalloproteinase-3 ( $p<0.001$ ), and IL-6 ( $p=0.001$ ), and were inversely correlated with hemoglobin ( $p=0.005$ ). Anti-Pg-LPS IgG antibody levels were inversely correlated with activity indices such as patient global assessments using visual analogue scale (VAS) ( $p=0.002$ ) and painVAS ( $p<0.001$ ). Total bacteria counts were correlated with ENC ( $p<0.001$ ), and inversely correlated with serum LPS ( $p<0.001$ ) and anti-Pg-LPS IgA antibody levels ( $p<0.001$ ). These results suggest that substances from oral and gut microbiota may influence disease activity in RA patients.

Lipopolysaccharide-binding protein as a risk factor for development of infectious and inflammatory postsurgical complications in colorectal cancer paients

Aim of the study

In this pilot study lipopolysaccharide-binding protein (LBP) levels were assessed as a possible risk factor for development of systemic inflammatory response syndrome (SIRS) and infectious and inflammatory complications in colorectal cancer (CRC) patients after surgery.

Material and methods

For LBP determination venous blood was taken 1 hour before the surgery and 72 hours after it. All patients were stratified by the presence or absence of acute bowel obstruction (ABO), SIRS and complications.

Results

36 patients with CRC participated in the study. The LBP level before surgery was 879.8 ± 221.8 ng/ml (interquartile range (IQR) 749.3-1028.8); on the 3^rd day it was 766.5 ± 159.4 ng/ml (IQR 669.5-847.6), which was a statistically significant decrease (p = 0.004). A decrease in LBP level by more than 280 ng/ml increases the probability of SIRS and complications in operated CRC patients (OR 6.6, 95% CI: 1.1-40.9 and OR 12.0, 95% CI: 1.8-80.4, respectively). In patients with ABO in the presence of SIRS, the LBP value decreased more than in those without SIRS (p = 0.046).

Conclusions

This study demonstrated that the LBP level in the operated CRC patients tends to decrease on the 3^rd day after surgery. A bigger decrease in LBP level increases the probability of SIRS and postoperative infectious and inflammatory complications. Therefore, further studies with larger numbers of patients are required.

Microbial interaction: Prevotella spp. reduce P. aeruginosa induced inflammation in cystic fibrosis bronchial epithelial cells

BACKGROUND

In Cystic Fibrosis (CF) airways, the dehydrated, thick mucus promotes the establishment of persistent polymicrobial infections and drives chronic airways inflammation. This also predisposes the airways to further infections, the vicious, self-perpetuating cycle causing lung damage and progressive lung function decline. The airways are a poly-microbial environment, containing both aerobic and anaerobic bacterial species. Pseudomonas aeruginosa (P. aeruginosa) infections contribute to the excessive inflammatory response in CF, but the role of anaerobic Prevotella spp., frequently found in CF airways, is not known.

MATERIALS

We assessed innate immune signalling in CF airway epithelial cells in response to clinical strains of P. histicola, P. nigresens and P. aeruginosa. CFBE41o- cells were infected with P. aeruginosa (MOI 100, 2h) followed by infection with P. histicola or P. nigrescens (MOI 100, 2h). Cells were incubated under anaerobic conditions for the duration of the experiments.

RESULTS

Our study shows that P. histicola and P. nigresens can reduce the growth of P. aeruginosa and dampen the inflammatory response in airway epithelial cells. We specifically illustrate that the presence of the investigated Prevotella spp. reduces Toll-like-receptor (TLR)-4, MAPK, NF-κB(p65) signalling and cytokine release (Interleukin (IL)-6, IL-8) in mixed infections.

CONCLUSION

Our work, for the first time, strongly indicates a relationship between P. aeruginosa and anaerobic Prevotella spp.. The observed modified NF-κB and MAPK signalling indicates some mechanisms underlying this interaction that could offer a novel therapeutic approach to combat chronic P. aeruginosa infection in people with CF.

The effect of intraoperative goal-directed crystalloid versus colloid administration on perioperative inflammatory markers - a substudy of a randomized controlled trial

Background

Excessive perioperative fluid administration may result in iatrogenic endothelial dysfunction and tissue edema, transducing inflammatory markers into the bloodstream. Colloids remain longer in the circulation, requiring less volume to reach similar hemodynamic endpoints compared to crystalloids. Thus, we tested the hypothesis that a goal-directed colloid regimen attenuates the inflammatory response compared to a goal-directed crystalloid regime.

Methods

Patients undergoing moderate- to high-risk open abdominal surgery were randomly assigned to goal-directed lactated Ringer’s solution (n = 58) or a hydroxyethyl starch 6% 130/0.4 (n = 62) fluid regimen. Our primary outcome was perioperative levels of pro- and anti-inflammatory cytokines. Secondary outcome was perioperative levels of white blood cell count (WBC), C-reactive protein (CRP), procalcitonin (PCT) and lipopolysaccharide-binding protein (LBP). Measurements were performed preoperatively, immediate postoperatively, on postoperative day one, two and four.

Results

The areas under the curve of Interleukin (IL) 6 (p = 0.60), IL 8 (p = 0.46), IL 10 (p = 0.68) and tumor necrosis factor α (p = 0.47) levels did not differ significantly between the groups. WBC, CRP and PCT values were also comparable. LBP, although significantly higher in the crystalloid group, remained in the normal range. Patients assigned to crystalloids received a median (IQR) amount of 3905 mL (2880–5288) of crystalloid. Patients assigned to colloids received 1557 mL (1207–2116) of crystalloid and 1250 mL (750–1938) of colloid.

Conclusion

Cytokine and inflammatory marker levels did not differ between goal-directed crystalloid and colloid administration after moderate to high-risk abdominal surgery.

Trial registration

ClinicalTrials.gov (NCT00517127). Registered 16th August 2007.

Differences in systemic humoral immune response among Balb/c mice administered with probiotic, LPS Escherichia coli, and probiotic-LPS E. coli

BACKGROUND AND OBJECTIVES

The aim of this study was to compare the systemic humoral immune responses, including IgE, IgA, IgG and IgM levels in Balb/c mice administered a probiotic, LPS derived from Escherichia coli (E.coli), and probiotic-LPS derived from E. coli.

MATERIALS AND METHODS

Thirty-two male Balb/c mice, 10-12 weeks of age with body weight ranging from 30-40 g were randomly divided into four experimental groups (n=8). The treatment regimens were as follows: Group 1, mice did not receive LPS or probiotic (control group); Group 2, mice received only LPS on the first day; Group 3, mice received probiotic for 7 days; Group 4, mice received LPS on the first day, and then continued, with probiotic for 7 days. The mice were observed for 8 days, and then, euthanized the next day (day 9). The serum was collected, and the levels of IgE, IgA, IgG and IgM were measured using ELISA.

RESULTS

The humoral immune response was higher in the presence of a probiotic compared to that in the control; IgE (9.02 ± 0.58 units/ml, p=0.000), IgA (3.26 ± 0.99 units/ml, p=0.316), IgG (7.29 ± 0.24 units/ml, p=0.000), and IgM (4.01 ± 2.98 units/ml, p=0.505). When administered with LPS E. coli along with probiotic, the humoral immune response was the highest; IgE (10.68 ± 1.63 units/ml, p=0.000), IgA (8.34 ± 1.47 units/ml, p=0.000), IgG (9.96 ± 0.98 units/ml, p=0.000), and IgM (4.31 ± 1.05 units/ml, p=0.319) compared to the control group.

CONCLUSION

Probiotic-LPS derived from E. coli treatment induced a higher humoral immune response (highest IgE, IgA, IgG and IgM levels) compared to treatment with probiotic only.

LPS-Binding Protein Modulates Acute Renal Fibrosis by Inducing Pericyte-to-Myofibroblast Trans-Differentiation through TLR-4 Signaling

During sepsis, the increased synthesis of circulating lipopolysaccharide (LPS)-binding protein (LBP) activates LPS/TLR4 signaling in renal resident cells, leading to acute kidney injury (AKI). Pericytes are the major source of myofibroblasts during chronic kidney disease (CKD), but their involvement in AKI is poorly understood. Here, we investigate the occurrence of pericyte-to-myofibroblast trans-differentiation (PMT) in sepsis-induced AKI. In a swine model of sepsis-induced AKI, PMT was detected within 9 h from LPS injection, as evaluated by the reduction of physiologic PDGFRβ expression and the dysfunctional α-SMA increase in peritubular pericytes. The therapeutic intervention by citrate-based coupled plasma filtration adsorption (CPFA) significantly reduced LBP, TGF-β, and endothelin-1 (ET-1) serum levels, and furthermore preserved PDGFRβ and decreased α-SMA expression in renal biopsies. In vitro, both LPS and septic sera led to PMT with a significant increase in Collagen I synthesis and α-SMA reorganization in contractile fibers by both SMAD2/3-dependent and -independent TGF-β signaling. Interestingly, the removal of LBP from septic plasma inhibited PMT. Finally, LPS-stimulated pericytes secreted LBP and TGF-β and underwent PMT also upon TGF-β receptor-blocking, indicating the crucial pro-fibrotic role of TLR4 signaling. Our data demonstrate that the selective removal of LBP may represent a therapeutic option to prevent PMT and the development of acute renal fibrosis in sepsis-induced AKI.

Protective effect of Cordyceps sinensis extract on lipopolysaccharide-induced acute lung injury in mice

Background: To study the protective effect of Cordyceps sinensis extract (Dong Chong Xia Cao in Chinese [DCXC]) on experimental acute lung injury (ALI) mice.

Methods and results: ALI model was induced by intratracheal-instilled lipopolysaccharide (LPS, 2.4 mg/kg) in BALB/c male mice. The mice were administrated DCXC (ig, 10, 30, 60 mg/kg) in 4 and 8 h after receiving LPS. Histopathological section, wet/dry lung weight ratio and myeloperoxidase activity were detected. Bronchoalveolar lavage fluid (BALF) was collected for cell count, the levels of tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), interleukin-6 (IL-6) and nitric oxide (NO) in BALF was detected by ELISA, the protein and mRNA expression of nuclear factor-κB p65 (NF-κB p65), inducible NO synthase (iNOS) and cyclooxygenase-2 (COX-2) in lung tissue was detected by Western blot and RT-PCR. The result showed that DCXC could reduce the degree of histopathological injury, wet/dry weight ratio (W/D ratio) and myeloperoxidase activity (P<0.05) with a dose-dependent manner. The increased number of total cells, neutrophils and macrophages in BALF were significantly inhibited by DCXC treatment (P<0.05). The increased levels of TNF-α, IL-1β, IL-6 and NO in BALF after LPS administration was significantly reduced by DCXC (P<0.05). In addition, the increased protein and mRNA levels of iNOS, COX-2 and NF-κB p65 DNA binding ability in LPS group were dose-dependently reduced by DCXC treatment (P<0.05).

Conclusion: DCXC could play an anti-inflammatory and antioxidant effect on LPS-induced ALI through inhibiting NF-κB p65 phosphorylation, and the expression of COX-2 and iNOS in lung. The result showed that DCXC has a potential protective effect on the ALI.

Acute Respiratory Distress Syndrome: Etiology, Pathogenesis, and Summary on Management

The acute respiratory distress syndrome (ARDS) has multiple causes and is characterized by acute lung inflammation and increased pulmonary vascular permeability, leading to hypoxemic respiratory failure and bilateral pulmonary radiographic opacities. The acute respiratory distress syndrome is associated with substantial morbidity and mortality, and effective treatment strategies are limited. This review presents the current state of the literature regarding the etiology, pathogenesis, and management strategies for ARDS.

Prognostic value of procalcitonin and lipopolysaccharide binding protein in cancer patients with chemotherapy-associated febrile neutropenia presenting to an emergency department

INTRODUCTION

Cancer patients with chemotherapy-induced febrile neutropenia are a heterogeneous group with a significant risk of serious medical complications. In these patients, the Multinational Association for Supportive Care in Cancer (MASCC) score is the most widely used tool for risk-stratification. The aim of this prospective study was to analyse the value of procalcitonin (PCT) and lipopolysaccharide binding protein (LBP) to predict serious complications and bacteraemia in cancer patients with febrile neutropenia, compared with MASCC score.

MATERIALS AND METHODS

Data were collected from 111 episodes of febrile neutropenia admitted consecutively to the emergency department. In all of them, MASCC score was calculated and serum samples were collected for measurement of PCT and LBP by well-established methods. The main and secondary outcomes were the development of serious complications and bacteraemia, respectively.

RESULTS

A serious complication occurred in 20 (18%) episodes and in 16 (14%) bacteraemia was detected. Areas under the receiver operating characteristic curve (ROC AUC) of MASCC score, PCT and LBP to select low-risk patients were 0.83 (95% confidence interval (CI): 0.74 - 0.89), 0.85 (95% CI: 0.77 - 0.91) and 0.70 (95% CI: 0.61 - 0.78), respectively. For bacteraemia, MASCC score, PCT and LBP showed ROC AUCs of 0.74 (95% CI: 0.64 - 0.82), 0.86 (95% CI: 0.78 - 0.92) and 0.76 (95% CI: 0.67 - 0.83), respectively.

CONCLUSION

A single measurement of PCT performs similarly as MASCC score to predict serious medical complications in cancer patients with febrile neutropenia and can be a useful tool for risk stratification. Besides, low PCT concentrations can be used to rule-out the presence of bacteraemia.

2'-Fluoro-Pyrimidine-Modified RNA Aptamers Specific for Lipopolysaccharide Binding Protein (LBP)

Lipopolysaccaride binding protein (LBP), a glycosylated acute phase protein, plays an important role in the pathophysiology of sepsis. LBP binds with high affinity to the lipid part of bacterial lipopolysaccaride (LPS). Inhibition of the LPS-LBP interaction or blockage of LBP-mediated transfer of LPS monomers to CD14 may be therapeutical strategies to prevent septic shock. LBP is also of interest as a biomarker to identify septic patients at high risk for death, as LBP levels are elevated during early stages of severe sepsis. As a first step toward such potential applications, we isolated aptamers specific for murine LBP (mLBP) by in vitro selection from a library containing a 60-nucleotide randomized region. Modified RNA pools were transcribed in the presence of 2′-fluoro-modified pyrimidine nucleotides to stabilize transcripts against nuclease degradation. As verified for one aptamer experimentally, the selected aptamers adopt a “three-helix junction” architecture, presenting single-stranded 7-nt (5′-YGCTTCY) or 6-nt (5′-RTTTCY) consensus sequences in their core. The best binder (aptamer A011; K_d of 270 nM for binding to mLBP), characterized in more detail by structure probing and boundary analysis, was demonstrated to bind with high specificity to murine LBP.

MicroRNAs as biomarkers of acute lung injury

Acute respiratory distress syndrome (ARDS) is a common and complex inflammatory lung diseases affecting critically ill patients requiring mechanical ventilation. MicroRNAs (miRNAs), a novel pathway of non-coding RNA molecules that regulate gene expression at the post-transcriptional level, have emerged as a novel class of gene expression, and can play important roles in inflammation or apoptosis, which are common manifestations of ARDS and diffuse alveolar damage (DAD). In the present review, we discuss the role of miRNAs as biomarkers of ARDS and DAD, and their potential use as therapeutic targets for this condition.

Molecular and Immune Biomarkers in Acute Respiratory Distress Syndrome: A Perspective From Members of the Pulmonary Pathology Society

Acute respiratory distress syndrome (ARDS) is a multifactorial syndrome with high morbidity and mortality rates, characterized by deficiency in gas exchange and lung mechanics that lead to hypoxemia, dyspnea, and respiratory failure. Histologically, ARDS is characterized by an acute, exudative phase, combining diffuse alveolar damage and noncardiogenic edema, followed by a later fibroproliferative phase. Despite an enhanced understanding of ARDS pathogenesis, the capacity to predict the development of ARDS and to risk-stratify patients with the disease remains limited. Biomarkers may help to identify patients at the greatest risk of developing ARDS, to evaluate response to therapy, to predict outcome, and to improve clinical trials. The ARDS pathogenesis is presented in this article, as well as concepts and information on biomarkers that are currently used clinically or are available for laboratory use by academic and practicing pathologists and the developing and validating of new assays, focusing on the assays' major biologic roles in lung injury and/or repair and to ultimately suggest innovative, therapeutic approaches.

Host responses to concurrent combined injuries in non-human primates

Background

Multi-organ failure (MOF) following trauma remains a significant cause of morbidity and mortality related to a poorly understood abnormal inflammatory response. We characterized the inflammatory response in a non-human primate soft tissue injury and closed abdomen hemorrhage and sepsis model developed to assess realistic injury patterns and induce MOF.

Methods

Adult male Mauritan Cynomolgus Macaques underwent laparoscopy to create a cecal perforation and non-anatomic liver resection along with a full-thickness flank soft tissue injury. Treatment consisted of a pre-hospital phase followed by a hospital phase after 120 minutes. Blood counts, chemistries, and cytokines/chemokines were measured throughout the study. Lung tissue inflammation/apoptosis was confirmed by mRNA quantitative real-time PCR (qPCR), H&E, myeloperoxidase (MPO) and TUNEL staining was performed comparing age-matched uninjured controls to experimental animals.

Results

Twenty-one animals underwent the protocol. Mean percent hepatectomy was 64.4 ± 5.6; percent blood loss was 69.0 ± 12.1. Clinical evidence of end-organ damage was reflected by a significant elevation in creatinine (1.1 ± 0.03 vs. 1.9 ± 0.4, p=0.026). Significant increases in systemic levels of IL-10, IL-1ra, IL-6, G-CSF, and MCP-1 occurred (11-2986-fold) by 240 minutes. Excessive pulmonary inflammation was evidenced by alveolar edema, congestion, and wall thickening (H&E staining). Concordantly, amplified accumulation of MPO leukocytes and significant pulmonary inflammation and pneumocyte apoptosis (TUNEL) was confirmed using qRT-PCR.

Conclusion

We created a clinically relevant large animal multi-trauma model using laparoscopy that resulted in a significant systemic inflammatory response and MOF. With this model, we anticipate studying systemic inflammation and testing innovative therapeutic options.

Biomarkers for the acute respiratory distress syndrome: how to make the diagnosis more precise

The acute respiratory distress syndrome (ARDS) is an acute inflammatory process of the lung caused by a direct or indirect insult to the alveolar-capillary membrane. Currently, ARDS is diagnosed based on a combination of clinical and physiological variables. The lack of a specific biomarker for ARDS is arguably one of the most important obstacles to progress in developing novel treatments for ARDS. In this article, we will review the current understanding of some appealing biomarkers that have been measured in human blood, bronchoalveolar lavage fluid (BALF) or exhaled gas that could be used for identifying patients with ARDS, for enrolling ARDS patients into clinical trials, or for better monitoring of patient's management. After a literature search, we identified several biomarkers that are associated with the highest sensitivity and specificity for the diagnosis or outcome prediction of ARDS: receptor for advanced glycation end-products (RAGE), angiopoietin-2 (Ang-2), surfactant protein D (SP-D), inteleukin-8, Fas and Fas ligand, procollagen peptide (PCP) I and III, octane, acetaldehyde, and 3-methylheptane. In general, these are cell-specific for epithelial or endothelial injury or involved in the inflammatory or infectious response. No biomarker or biomarkers have yet been confirmed for the diagnosis of ARDS or prediction of its prognosis. However, it is anticipated that in the near future, using biomarkers for defining ARDS, or for determining those patients who are more likely to benefit from a given therapy will have a major effect on clinical practice.

Epidemiology and Changes in Mortality of Sepsis After the Implementation of Surviving Sepsis Campaign Guidelines

PURPOSE

To determine the epidemiology and outcome of severe sepsis and septic shock after 9 years of the implementation of the Surviving Sepsis Campaign (SSC) and to build a mortality prediction model.

METHODS

This is a prospective, multicenter, observational study performed during a 5-month period in 2011 in a network of 11 intensive care units (ICUs). We compared our findings with those obtained in the same ICUs in a study conducted in 2002.

RESULTS

The current cohort included 262 episodes of severe sepsis and/or septic shock, and the 2002 cohort included 324. The prevalence was 14% (95% confidence interval: 12.5-15.7) with no differences to 2002. The population-based incidence was 31 cases/100 000 inhabitants/year. Patients in 2011 had a significantly lower Acute Physiology and Chronic Health Evaluation II (APACHE II; 21.9 ± 6.6 vs 25.5 ± 7.07), Logistic Organ Dysfunction Score (5.6 ± 3.2 vs 6.3 ± 3.6), and Sequential Organ Failure Assessment (SOFA) scores on day 1 (8 ± 3.5 vs 9.6 ± 3.7; P < .01). The main source of infection was intraabdominal (32.5%) although microbiologic isolation was possible in 56.7% of cases. The 2011 cohort had a marked reduction in 48-hour (7% vs 14.8%), ICU (27.2% vs 48.2%), and in-hospital (36.7% vs 54.3%) mortalities. Most relevant factors associated with death were APACHE II score, age, previous immunosuppression and liver insufficiency, alcoholism, nosocomial infection, and Delta SOFA score.

CONCLUSION

Although the incidence of sepsis/septic shock remained unchanged during a 10-year period, the implementation of the SSC guidelines resulted in a marked decrease in the overall mortality. The lower severity of patients on ICU admission and the reduced early mortality suggest an improvement in early diagnosis, better initial management, and earlier antibiotic treatment.

On the translocation of bacteria and their lipopolysaccharides between blood and peripheral locations in chronic, inflammatory diseases: the central roles of LPS and LPS-induced cell death

We have recently highlighted (and added to) the considerable evidence that blood can contain dormant bacteria. By definition, such bacteria may be resuscitated (and thus proliferate). This may occur under conditions that lead to or exacerbate chronic, inflammatory diseases that are normally considered to lack a microbial component. Bacterial cell wall components, such as the endotoxin lipopolysaccharide (LPS) of Gram-negative strains, are well known as potent inflammatory agents, but should normally be cleared. Thus, their continuing production and replenishment from dormant bacterial reservoirs provides an easy explanation for the continuing, low-grade inflammation (and inflammatory cytokine production) that is characteristic of many such diseases. Although experimental conditions and determinants have varied considerably between investigators, we summarise the evidence that in a great many circumstances LPS can play a central role in all of these processes, including in particular cell death processes that permit translocation between the gut, blood and other tissues. Such localised cell death processes might also contribute strongly to the specific diseases of interest. The bacterial requirement for free iron explains the strong co-existence in these diseases of iron dysregulation, LPS production, and inflammation. Overall this analysis provides an integrative picture, with significant predictive power, that is able to link these processes via the centrality of a dormant blood microbiome that can resuscitate and shed cell wall components.

Lipopolysaccharide-binding protein is efficient in biodosimetry during radiotherapy of lung cancer

The aim of the present study was to determine if the serum levels of early markers of inflammation, such as interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), C-reactive protein (CRP), and lipopolysaccharide-binding protein (LBP) were correlated with the radiation dose received by the pulmonary and mediastinal structures of patients with non-small cell lung cancer (NSCLC). This pilot study included 26 patients with NSCLC who received total radiation doses ranging from 54 to 74 Gy (2.0 Gy/fraction). Cytokines were measured at baseline by enzyme-linked immunosorbant assay, and following administration of total doses of 20 and 40 Gy. A control group of 26 participants was sampled for comparisons with patient baseline cytokine levels. Only data from the 40-Gy cytokine blood levels of patients with NSCLC were identified to be correlated with histograms of the parameters of each patient's radiotherapy protocol. The IL-6, TNF-α and CRP median baseline levels of the patients with NSCLC were significantly higher than those of the controls (all P≤0.01). No differences were observed between the LBP levels of the patients and controls [median, 36.34 (25-75%; 31.35-39.27) vs. 36.92 (30.20-44.05) µg/ml, respectively; P=0.42]. No significant differences in the levels of the four cytokines between baseline, and at 20 and 40 Gy were observed [IL-6 (P=0.19); TNF-α (P=0.68); CRP (P=0.44) and LBP (P=0.29)]. LBP was significantly and positively correlated with the mean radiation dose to the lung (r=0.409; P=0.038), and showed a positive correlation with the percentage of lung volume exposed to at least 20 Gy of the planned radiation dose (r=0.3536; P=0.0764). CRP levels were positively correlated with the mean radiation dose to the esophagus (r=0.404; P=0.041); however, IL-6, TNF-α and CRP were not significantly associated with other lung dosimetry parameters. Thus, LBP levels were correlated with radiation exposure of pulmonary tissues, and LBP may be a marker that warrants further investigation on radiotoxicity in NSCLC patients.

A Pathophysiologic Approach to Biomarkers in Acute Respiratory Distress Syndrome

Acute respiratory distress syndrome (ARDS) is an acute-onset hypoxic condition with radiographic bilateral lung infiltration. It is characterized by an acute exudative phase combining diffuse alveolar damage and lung edema followed by a later fibroproliferative phase. Despite an improved understanding of ARDS pathobiology, our ability to predict the development of ARDS and risk-stratify patients with the disease remains limited. Biomarkers may help to identify patients at the highest risk of developing ARDS, assess response to therapy, predict outcome, and optimize enrollment in clinical trials. After a short description of ARDS pathobiology, here, we review the scientific evidence that supports the value of various ARDS biomarkers with regard to their major biological roles in ARDS-associated lung injury and/or repair. Ongoing research aims at identifying and characterizing novel biomarkers, in order to highlight relevant mechanistic explorations of lung injury and repair, and to ultimately develop innovative therapeutic approaches for ARDS patients. This review will focus on the pathophysiologic, diagnostic, and therapeutic implications of biomarkers in ARDS and on their utility to ultimately improve patient care.

Prognostic Value and Daily Trend of Interleukin-6, Neutrophil CD64 Expression, C-Reactive Protein and Lipopolysaccharide-Binding Protein in Critically Ill Patients: Reliable Predictors of Outcome or Not?

Background

Severe sepsis and/or trauma complicated by multiple organ dysfunction syndrome are the leading causes of death in critically ill patients. The aim of this prospective single-centre study was to assess the prognostic value and daily trend of interleukin-6 (IL-6), neutrophil CD64 expression, C-reactive protein (CRP) and lipopolysaccharide-binding protein (LBP) regarding outcome in critically ill patients with severe trauma and/or severe sepsis. Outcome measure was hospital mortality.

Methods

One hundred and two critically ill patients admitted to the intensive care unit of a tertiary university hospital were enrolled in this prospective study. Blood samples were collected on admission (day 1), days 2 and 3.

Results

CD64 index was 1.6-fold higher on day 1 and 1.78-fold higher on day 2 in non-survivors (p<0.05). The area under the curve (AUC) for the CD64 index on day 1 for outcome was 0.727. At a cut-off level of 2.80 sensitivity was 75% and specificity was 65%. Patients with CD64 index level on day 1 higher than 2.80 had 2.4-fold higher probability of dying. Odds ratio is 2.40; 95% CI 0.60–9.67.

Conclusions

CD64 index on day 1 is a fairly good predictor of outcome. AUCs for IL-6, CRP and LBP were < 0.55, suggesting these biomarkers failed to predict outcome.

Discovery and Validation of Predictive Biomarkers of Survival for Non-small Cell Lung Cancer Patients Undergoing Radical Radiotherapy: Two Proteins With Predictive Value

Lung cancer is the most frequent cause of cancer-related death world-wide. Radiotherapy alone or in conjunction with chemotherapy is the standard treatment for locally advanced non-small cell lung cancer (NSCLC). Currently there is no predictive marker with clinical utility to guide treatment decisions in NSCLC patients undergoing radiotherapy. Identification of such markers would allow treatment options to be considered for more effective therapy. To enable the identification of appropriate protein biomarkers, plasma samples were collected from patients with non-small cell lung cancer before and during radiotherapy for longitudinal comparison following a protocol that carries sufficient power for effective discovery proteomics. Plasma samples from patients pre- and during radiotherapy who had survived > 18 mo were compared to the same time points from patients who survived < 14 mo using an 8 channel isobaric tagging tandem mass spectrometry discovery proteomics platform. Over 650 proteins were detected and relatively quantified. Proteins which showed a change during radiotherapy were selected for validation using an orthogonal antibody-based approach. Two of these proteins were verified in a separate patient cohort: values of CRP and LRG1 combined gave a highly significant indication of extended survival post one week of radiotherapy treatment.

Sepsis biomarkers

Sepsis is the most frequent cause of death in non-coronary intensive care units (ICUs). In the past 10 years, progress has been made in the early identification of septic patients and in their treatment and these improvements in support and therapy mean that the mortality is gradually decreasing but it still remains unacceptably high. Leaving clinical diagnosis aside, the laboratory diagnostics represent a complex range of investigations that can place significant demands on the system given the speed of response required. There are hundreds of biomarkers which could be potentially used for diagnosis and prognosis in septic patients. The main attributes of successful markers would be high sensitivity, specificity, possibility of bed-side monitoring, and financial accessibility. Only a fraction is used in routine clinical practice because many lack sufficient sensitivity or specificity. The following review gives a short overview of the current epidemiology of sepsis, its pathogenesis and state-of-the-art knowledge on the use of specific biochemical, hematological and immunological parameters in its diagnostics. Prospective approaches towards discovery of new diagnostic biomarkers have been shortly mentioned.

Laboratory detection of sepsis: biomarkers and molecular approaches

Sepsis, severe sepsis, and septic shock cause significant morbidity and mortality worldwide. Rapid diagnosis and therapeutic interventions are desirable to improve the overall mortality in patients with sepsis. However, gold standard laboratory diagnostic methods for sepsis, pose a significant challenge to rapid diagnosis of sepsis by physicians and laboratories. This article discusses the usefulness and potential of biomarkers and molecular test methods for a more rapid clinical and laboratory diagnosis of sepsis. Because new technologies are quickly emerging, physicians and laboratories must appreciate the key factors and characteristics that affect the clinical usefulness and diagnostic accuracy of these test methodologies.

Proteomics reveals age-related differences in the host immune response to sepsis

Sepsis is commonly caused by community-acquired pneumonia (CAP) and may develop into severe sepsis, characterized by multiple organ failure. The risk of severe sepsis among CAP patients and subsequent mortality increases sharply after the age of 65. The molecular mechanisms associated with this age-related risk are not fully understood. To better understand factors involved with increased incidence and mortality of severe sepsis in the elderly, we used a nested case-control study of patients enrolled in a multicenter observational cohort of 2320 participants with CAP. We identified a total of 39 CAP patients 50-65 and 70-85 years old who did or did not develop severe sepsis. Plasma samples were obtained on presentation to the emergency department and prior to therapeutic interventions. A semiquantitative plasma proteomics workflow was applied which incorporated tandem immunoaffinity depletion, iTRAQ labeling, strong cation exchange fractionation, and nanoflow liquid chromatography coupled to high-resolution mass spectrometry. In total, 772 proteins were identified, of which 58 proteins exhibit statistically significant differences in expression levels among patients with severe sepsis as a function of age. Differentially expressed proteins are involved in pathways such as acute phase response, coagulation signaling, atherosclerosis signaling, lipid metabolism, and production of nitric oxide and reactive oxygen species. This study provides insight into factors that may explain age-related differences in incidence of severe sepsis in the elderly.

Revisiting the white blood cell count: immature granulocytes count as a diagnostic marker to discriminate between SIRS and sepsis--a prospective, observational study

Background

Sepsis is a serious disease condition and a major cause of intensive care unit (ICU) admission. Its diagnosis in critically ill patients is complicated. To diagnose an infection rapidly, and to accurately differentiate systemic inflammatory response syndrome (SIRS) from sepsis, is challenging yet early diagnosis is vital for early induction of an appropriate therapy. The aim of this study was to evaluate whether the immature granulocyte (IG) count is a useful early diagnostic marker of sepsis compared to other markers. Therefore, a total of 70 consecutive surgical intensive care patients were assessed. IGs were measured from whole blood samples using an automated analyzer. C-reactive protein (CRP), lipopolysaccharide binding protein (LBP) and interleukin-6 (IL-6) concentrations were also determined. The observation period was a maximum of 21 days and ended with the patients’ discharge from ICU or death. Receiver operating characteristic (ROC) analyses were conducted and area under the curve (AUC) was calculated to determine sensitivities and specificities for the parameters.

Results

We found that the IG count significantly discriminates between infected and non-infected patients (P < 0.0001) with a sensitivity of 89.2% and a specificity of 76.4%, particularly within the first 48 hours after SIRS onset. Regarding the discriminative power for infection, the IG count was more indicative than other clinical parameters such as CRP, LBP and IL-6, which had a sensitivity of less than 68%. Additionally, the highest diagnostic odds ratio (DOR) with 26.7 was calculated for the IG count within the first 48 hours. During the course of the disease ROC curve analyses showed a superior positive predictive value of the IG count compared to the other measured parameters during the first five days following the fulfillment of SIRS criteria. However, the number of IGs was not correlated with ICU mortality.

Conclusions

The total number of IG in peripheral blood from ICU patients is a good marker to discriminate infected and non-infected patients very early during SIRS. However, the IG count is not suitable as a prognostic marker for mortality. Routine and serial measurement of IGs may provide new possibilities for rapid screening of SIRS patients on ICU with suspected infections.

Fish oil attenuates omega-6 polyunsaturated fatty acid-induced dysbiosis and infectious colitis but impairs LPS dephosphorylation activity causing sepsis

Clinically, excessive ω-6 polyunsaturated fatty acid (PUFA) and inadequate ω-3 PUFA have been associated with enhanced risks for developing ulcerative colitis. In rodent models, ω-3 PUFAs have been shown to either attenuate or exacerbate colitis in different studies. We hypothesized that a high ω-6: ω-3 PUFA ratio would increase colitis susceptibility through the microbe-immunity nexus. To address this, we fed post-weaned mice diets rich in ω-6 PUFA (corn oil) and diets supplemented with ω-3 PUFA (corn oil+fish oil) for 5 weeks. We evaluated the intestinal microbiota, induced colitis with Citrobacter rodentium and followed disease progression. We found that ω-6 PUFA enriched the microbiota with Enterobacteriaceae, Segmented Filamentous Bacteria and Clostridia spp., all known to induce inflammation. During infection-induced colitis, ω-6 PUFA fed mice had exacerbated intestinal damage, immune cell infiltration, prostaglandin E2 expression and C. rodentium translocation across the intestinal mucosae. Addition of ω-3 PUFA on a high ω-6 PUFA diet, reversed inflammatory-inducing microbial blooms and enriched beneficial microbes like Lactobacillus and Bifidobacteria, reduced immune cell infiltration and impaired cytokine/chemokine induction during infection. While, ω-3 PUFA supplementation protected against severe colitis, these mice suffered greater mortality associated with sepsis-related serum factors such as LPS binding protein, IL-15 and TNF-α. These mice also demonstrated decreased expression of intestinal alkaline phosphatase and an inability to dephosphorylate LPS. Thus, the colonic microbiota is altered differentially through varying PUFA composition, conferring altered susceptibility to colitis. Overall, ω-6 PUFA enriches pro-inflammatory microbes and augments colitis; but prevents infection-induced systemic inflammation. In contrast, ω-3 PUFA supplementation reverses the effects of the ω-6 PUFA diet but impairs infection-induced responses resulting in sepsis. We conclude that as an anti-inflammatory agent, ω-3 PUFA supplementation during infection may prove detrimental when host inflammatory responses are critical for survival.

Predictors of survival in sepsis: what is the best inflammatory marker to measure?

PURPOSE OF REVIEW

Sepsis is relevant due to its high morbidity and mortality. For both sepsis diagnosis and outcome prediction many biomarkers have been described in the literature. Most of these markers are objects of scientific interest rather than being introduced into daily clinical practice. However, due to their unspecific character and their insufficient predictive value for the individual person, research focus is still on new aspects in sepsis-related biomarkers.

RECENT FINDINGS

Beyond the widely used acute-phase proteins C-reactive protein (CRP) and procalcitonin (PCT), many new molecules have been studied deriving from different organs or cells affected, due to the systemic nature of sepsis. Cytokines, coagulation factors/characteristics, vasoactive hormones, and several others have been recently proved to be relevant in sepsis syndrome and probably useful for outcome prediction. However, single time point measurements may be less predictive than consideration of the time-dependent course of parameters. Clinical decision just based on a biomarker is still not feasible because of the huge inter-individual differences in the inflammatory response.

SUMMARY

Many biomarkers display relevant correlation with the clinical outcome of patients with severe sepsis and septic shock. Consideration of their time courses may be more reliable than absolute levels. Clinical decision should not be based only on biomarkers but organ dysfunctions, for example, should also be taken into account.

Elevated plasma levels of heparin-binding protein in intensive care unit patients with severe sepsis and septic shock

INTRODUCTION

Rapid detection of, and optimized treatment for, severe sepsis and septic shock is crucial for successful outcome. Heparin-binding protein (HBP), a potent inducer of increased vascular permeability, is a potentially useful biomarker for predicting outcome in patients with severe infections. Our aim was to study the systemic release and dynamics of HBP in the plasma of patients with severe sepsis and septic shock in the ICU.

METHODS

A prospective study was conducted of two patient cohorts treated in the ICU at Karolinska University Hospital Huddinge in Sweden. A total of 179 patients was included, of whom 151 had sepsis (126 with septic shock and 25 patients with severe sepsis) and 28 a non-septic critical condition. Blood samples were collected at five time points during six days after admission.

RESULTS

HBP levels were significantly higher in the sepsis group as compared to the control group. At admission to the ICU, a plasma HBP concentration of ≥ 15 ng/mL and/or a HBP (ng/mL)/white blood cell count (109/L) ratio of >2 was found in 87.2% and 50.0% of critically ill patients with sepsis and non-septic illness, respectively. A lactate level of >2.5 mmol/L was detected in 64.9% and 56.0% of the same patient groups. Both in the sepsis group (n = 151) and in the whole group (n = 179), plasma HBP concentrations at admission and in the last measured sample within the 144 hour study period were significantly higher among 28-day non-survivors as compared to survivors and in the sepsis group, an elevated HBP-level at baseline was associated with an increased case-fatality rate at 28 days.

CONCLUSIONS

Plasma HBP levels were significantly higher in patients with severe sepsis or septic shock compared to patients with a non-septic illness in the ICU. HBP was associated with severity of disease and an elevated HBP at admission was associated with an increased risk of death. HBP that rises over time may identify patients with a deteriorating prognosis. Thus, repeated HBP measurement in the ICU may help monitor treatment and predict outcome in patients with severe infections.

Biomarkers in acute lung injury

Acute respiratory distress syndrome (ARDS) and acute lung injury (ALI) result in high permeability pulmonary edema causing hypoxic respiratory failure with high morbidity and mortality. As the population ages, the incidence of ALI is expected to rise. Over the last decade, several studies have identified biomarkers in plasma and bronchoalveolar lavage fluid providing important insights into the mechanisms involved in the pathophysiology of ALI. Several biomarkers have been validated in subjects from the large, multicenter ARDS clinical trials network. Despite these studies, no single or group of biomarkers has made it into routine clinical practice. New high throughput "omics" techniques promise improved understanding of the biologic processes in the pathogenesis in ALI and possibly new biomarkers that predict disease and outcomes. In this article, we review the current knowledge on biomarkers in ALI.

Biomarkers in acute lung injury--marking forward progress

This article reviews the state of the art regarding biomarkers for prediction, diagnosis, and prognosis in acute lung injury. Biomarkers and the goals of biomarker research are defined. Progress along 4 general routes is examined. First, the results of wide-ranging existing protein biomarkers are reported. Second, newer biomarkers awaiting or with strong potential for validation are described. Third, progress in the fields of genomics and proteomics is reported. Finally, given the complexity and number of potential biomarkers, the results of combining clinical predictors with protein and other biomarkers to produce better prognostic and diagnostic indices are examined.

LPS-induced galectin-3 oligomerization results in enhancement of neutrophil activation

Galectin-3 (Gal 3) is a glycan-binding protein that can be secreted by activated macrophages and mast cells at inflammation sites and plays an important role in inflammatory diseases caused by Bacteria and their products, such as lipopolysaccharides (LPS). Although it is well established that Gal 3 can interact with LPS, the pathophysiological importance of LPS/Gal 3 interactions is not fully understood. Data presented herein demonstrate for the first time that the interaction of Gal 3, either via its carbohydrate binding C-terminal domain or via its N-terminal part, with LPS from different bacterial strains, enhances the LPS-mediated neutrophil activation in vitro. Gal 3 allowed low LPS concentrations (1 µg/mL without serum, 1 ng/mL with serum) to upregulate CD11b expression and reactive oxygen species (ROS) generation on human neutrophils in vitro and drastically enhanced the binding efficiency of LPS to the neutrophil surface. These effects required LPS preincubation with Gal 3, before neutrophil stimulation and involved specific Gal 3/LPS interaction. A C-terminal Gal-3 fragment, which retains the lectin domain but lacks the N-terminal part, was still able to bind both to Escherichia coli LPS and to neutrophils, but had lost the ability to enhance neutrophil response to LPS. This result emphasizes the importance of an N-terminus-mediated Gal 3 oligomerization induced by its interaction with LPS. Finally we demonstrated that Balb/C mice were more susceptible to LPS-mediated shock when LPS was pretreated with Gal 3. Altogether, these results suggest that multimeric interactions between Gal 3 oligomers and LPS potentiate its pro-inflammatory effects on neutrophils.

Biomarkers of immune dysfunction following combination antiretroviral therapy for HIV infection

Combination antiretroviral therapy (cART) has significantly reduced morbidity and mortality of HIV-infected patients, yet their life expectancy remains reduced compared with the general population. Most HIV-infected patients receiving cART have some persistent immune dysfunction characterized by chronic immune activation and premature aging of the immune system. Here we review biomarkers of T-cell activation (CD69, -25 and -38, HLA-DR, and soluble CD26 and -30); generalized immune activation (C-reactive protein, IL-6 and D-dimer); microbial translocation (lipopolysaccharide, 16S rDNA, lipopolysaccharide-binding protein and soluble CD14); and immune dysfunction of specific cellular subsets (T cells, natural killer cells and monocytes) in HIV-infected patients on cART and their relationship to adverse clinical outcomes including impaired CD4 T-cell recovery, as well as non-AIDS clinical events, such as cardiovascular disease.

Lipopolysaccharide-binding protein for monitoring of postoperative sepsis: complemental to C-reactive protein or redundant?

INTRODUCTION

To prospectively evaluate the performance of Lipopolysaccharide-Binding Protein (LBP) in prediction of hospital mortality and its correlation to C-reactive Protein (CRP), we studied sixty consecutive, postoperative patients with sepsis admitted to the university hospital intensive care unit.

MEASUREMENTS AND METHODS

Plasma LBP and CRP were serially measured from day(d)1 (onset of sepsis) to d14 in parallel with clinical data until d28. Predictive value and correlation of LBP and CRP were analyzed by Receiver Operating Characteristic (ROC) curve analysis and Pearson's test, respectively.

MAIN RESULTS

LBP and CRP showed the highest levels on d2 or d3 after the onset of sepsis with no significant difference between survivors and nonsurvivors. Only at d7, nonsurvivors had significantly (p = .03) higher levels of CRP than survivors. Accordingly, in ROC analysis, concentration of CRP and LBP on d7 poorly discriminated survivors from nonsurvivors (area under curve = .62 and .55, respectively) without significant difference between LBP- and CRP-ROC curves for paired comparison. LBP and CRP plasma levels allocated to quartiles correlated well with each other (r(2) = .95; p = .02). Likewise, changes in plasma concentrations of LBP and CRP from one observation to the next showed a marked concordance as both parameters concomitantly increased or decreased in 76% of all cases.

CONCLUSIONS

During the first 14 days of postoperative sepsis, LBP plasma concentrations showed a time course that was very similar to CRP with a high concordance in the pattern of day-to-day changes. Furthermore, like CRP, LBP does not provide a reliable clue for outcome in this setting.

Infection after acute ischemic stroke: risk factors, biomarkers, and outcome

Background. The activation of inflammatory cascades triggered by ischemic stroke may play a key role in the development of infections. Methods. Patients admitted with ischemic stroke within 24 hours were prospectively enrolled. Biomarkers of infection were measured on days 1, 3, and 5. The patients were continuously monitored for predefined infections. Results. Patients with infection were older (OR 1.06 per year, 95% CI 1.01–1.11) and had a higher National Institute of Health Stroke Scale Score (NIHSS, OR 1.21, 95% CI 1.10–1.34), localization in the insula, and higher stroke volumes on diffusion-weighted imaging. The maximum temperature on days 1 and 3, leukocytes, interleukin-6, lipopolysaccharide-binding protein on days 1, 3, and 5, C-reactive protein on days 3 and 5, and procalcitonin on day 5 were higher and HLA-DR-expression on monocytes on days 1, 3, and 5 lower in patients with infection. Age and NIHSS predicted the development of infections. Infection was an independent predictor of poor functional outcome. Conclusions. Severe stroke and increasing age were shown to be early predictors for infections after stroke.

Acute respiratory distress syndrome definition: do we need a change?

PURPOSE OF REVIEW

Since the first description of the acute respiratory distress syndrome (ARDS) in 1967, no specific clinical sign or diagnostic test has yet been described that identifies ARDS. Its diagnosis is based on a combination of clinical, hemodynamic, and oxygenation criteria. The purpose of this review is to examine the current definition for ARDS and to discuss why this definition may not be the most appropriate definition for this syndrome.

RECENT FINDINGS

We will briefly review our current understanding of ARDS, discuss the problems with its current diagnosis, and present clinical, pathological, and biochemical evidences supporting a more appropriate definition for ARDS. In addition, we will discuss recent efforts to identify biological markers for lung injury in pulmonary edema fluid and blood collected from critically ill patients.

SUMMARY

On the basis of current evidence, it is time for a change in the ARDS definition. A newer classification system that recognizes different severities of pulmonary dysfunction is needed. Such a system should be able to identify patients that would be most responsive to supportive therapies and those unlikely to benefit because of the severity of their disease.

Common variants of TLR1 associate with organ dysfunction and sustained pro-inflammatory responses during sepsis

BACKGROUND

Toll-like receptors (TLRs) are critical components for host pathogen recognition and variants in genes participating in this response influence susceptibility to infections. Recently, TLR1 gene polymorphisms have been found correlated with whole blood hyper-inflammatory responses to pathogen-associated molecules and associated with sepsis-associated multiorgan dysfunction and acute lung injury (ALI). We examined the association of common variants of TLR1 gene with sepsis-derived complications in an independent study and with serum levels for four inflammatory biomarkers among septic patients.

METHODOLOGY/PRINCIPAL FINDINGS

Seven tagging single nucleotide polymorphisms of the TLR1 gene were genotyped in samples from a prospective multicenter case-only study of patients with severe sepsis admitted into a network of intensive care units followed for disease severity. Interleukin (IL)-1β, IL-6, IL-10, and C-reactive protein (CRP) serum levels were measured at study entry, at 48 h and at 7(th) day. Alleles -7202G and 248Ser, and the 248Ser-602Ile haplotype were associated with circulatory dysfunction among severe septic patients (0.001 ≤ p ≤ 0.022), and with reduced IL-10 (0.012 ≤ p ≤ 0.047) and elevated CRP (0.011 ≤ p ≤ 0.036) serum levels during the first week of sepsis development. Additionally, the -7202GG genotype was found to be associated with hospital mortality (p = 0.017) and ALI (p = 0.050) in a combined analysis with European Americans, suggesting common risk effects among studies.

CONCLUSIONS/SIGNIFICANCE

These results partially replicate and extend previous findings, supporting that variants of TLR1 gene are determinants of severe complications during sepsis.