Vascular endothelial growth factor in severe sepsis and septic shock

Novel biomarkers to identify complicated course of febrile neutropenia in hematological patients receiving intensive chemotherapy

Febrile neutropenia (FN) is a common consequence of intensive chemotherapy in hematological patients. More than 90% of the patients with acute myeloid leukemia (AML) develop FN, and 5%-10% of them die from subsequent sepsis. FN is very common also in autologous stem cell transplant recipients, but the risk of death is lower than in AML patients. In this review, we discuss biomarkers that have been evaluated for diagnostic and prognostic purposes in hematological patients with FN. In general, novel biomarkers have provided little benefit over traditional inflammatory biomarkers, such as C-reactive protein and procalcitonin. The utility of most biomarkers in hematological patients with FN has been evaluated in only a few small studies. Although some of them appear promising, much more data is needed before they can be implemented in the clinical evaluation of FN patients. Currently, close patient follow-up is key to detect complicated course of FN and the need for further interventions such as intensive care unit admission. Scoring systems such as q-SOFA (Quick Sequential Organ Failure Assessment) or NEWS (National Early Warning Sign) combined with traditional and/or novel biomarkers may provide added value in the clinical evaluation of FN patients.

Evaluation of endothelial glycocalyx injury biomarkers in feline hemotropic mycoplasmosis

The present study aimed to investigate endothelial glycocalyx (eGCx) damage in cats with feline hemotropic mycoplasmosis caused by Mycoplasma haemofelis using selected biomarkers and to determine the diagnostic and prognostic significance of these biomarkers. The study included 25 cats with feline hemotropic mycoplasmosis and 10 healthy cats. Clinical examination, blood gas analysis, complete blood count, and biochemical analysis were performed. Hemotropic mycoplasmosis diagnosed by microscopic examination and molecularly confirmed by PCR targeting the Mycoplasma haemofelis 16s rRNA gene. To evaluate endothelial glycocalyx damage, syndecan-1, endothelin-1 (ET-1), asymmetric dimethylarginine (ADMA), and vascular endothelial growth factor-A (VEGF-A) concentrations were measured using cat-specific commercial ELISA kits. Of the cats with feline hemotropic mycoplasmosis, 14 (56%) survived and 11 (44%) died. While syndecan-1 and ET-1 concentrations were significantly higher in cats with hemotropic mycoplasmosis compared to the control group (p < 0.001), no statistically significant difference was found for ADMA and VEGF-A concentrations (p > 0.05). Endothelial glycocalyx biomarkers showed significant correlations with each other and with hematological parameters (p < 0.01). The results of the ROC analysis showed that ET-1 with area under the curve (AUC) of 0.821 (p < 0.01) and VEGF-A with AUC of 0.805 (p < 0.010) were found to be significant prognostic indicators. In conclusion, this study demonstrated that serum syndecan-1 and ET-1 can be used as diagnostic and serum ET-1 and VEGF-A as prognostic biomarkers in cats with hemotropic mycoplasmosis. Our results indicate the development of eGCx damage in feline hemotropic mycoplasmosis and suggest that glycocalyx disruption may contribute to the pathogenesis of the disease.

Biomarkers of endothelial activation and inflammation in dogs with organ dysfunction secondary to sepsis

Introduction

Alteration in endothelial function during sepsis is thought to play a key role in the progression of organ failure. We herein compared plasma concentrations of endothelial activation biomarkers vascular endothelial growth factor (VEGF), hyaluronan (HA), plasminogen activator inhibitor-1 (PAI-1) and von Willebrand factor (vWF), as well as inflammatory mediator concentrations (IL-6, IL-8, IL-10, C-reactive protein and monocyte chemoattractant protein-1) in dogs with sepsis to healthy dogs.

Methods

This study was a multicenter observational clinical trial conducted at two university teaching hospitals from February 2016 until July 2017. The study included 18 client-owned dogs hospitalized with sepsis and at least one distant organ dysfunction, as well as 20 healthy dogs. Plasma biomarker concentrations were measured using ELISA. Severity of illness in dogs with sepsis was calculated using the 5-variable acute physiologic and laboratory evaluation (APPLEFAST) score. Biomarker concentrations were compared between septic and healthy dogs using linear models.

Results

Septic peritonitis was the most frequent source of sepsis (11/18; 61%), followed by pneumonia (4/18; 22%). Ten dogs (56%) had only 1 organ dysfunction, whereas 3 dogs (17%) had 2, 3 (17%) had 3, 1 (6%) had 4 and 1 (6%) had 5 organ dysfunctions. The median APPLEFAST score in the septic dogs was 28.5 (Q1-Q3, 24-31). Mean plasma concentrations of all endothelial and inflammatory biomarkers, except vWF, were higher in the sepsis cohort than in controls. The mean endothelial biomarker concentrations in the septic cohort ranged from ~2.7-fold higher for HA (difference in means; 118.2 ng/mL, 95% credible limit; 44.5-221.7) to ~150-fold for VEGF (difference in means; 76.6 pg./mL, 95% credible limit; 33.0-143.4), compared to the healthy cohort. Fifteen dogs with sepsis (83%) died; 7 (46%) were euthanized and 8 (53%) died during hospitalization.

Conclusion

Dogs with naturally occurring sepsis and organ dysfunction had higher mean concentrations of biomarkers of endothelial activation and inflammation compared to healthy dogs, broadening our understanding of the pathophysiology of sepsis secondary to endothelial dysfunction.

Serum vascular endothelial growth factor affects tissue fluid accumulation and is associated with deteriorating tissue perfusion and oxygenation in severe sepsis: a prospective observational study

BACKGROUND

Positive fluid balance and tissue fluid accumulation are associated with adverse outcomes in sepsis. Vascular endothelial growth factor (VEGF) increases in sepsis, promotes vascular permeability, and may affect tissue fluid accumulation and oxygenation. We used near-infrared spectroscopy (NIRS) to estimate tissue hemoglobin (Hb) oxygenation and water (H₂O) levels to investigate their relationship with serum VEGF levels.

MATERIAL AND METHODS

New-onset severe sepsis patients admitted to the intensive care unit were enrolled. Relative tissue concentrations of oxy-Hb ([HbO₂]), deoxy-Hb ([HbR]), total Hb ([HbT]), and H₂O ([H₂O]) were estimated by near-infrared spectroscopy (NIRS) for three consecutive days and serum VEGF levels were measured. Comparisons between oliguric and non-oliguric patients were conducted and the correlations between variables were analyzed.

RESULTS

Among 75 eligible patients, compared with non-oliguric patients, oliguric patients were administrated more intravascular fluids (median [IQR], 1926.00 [1348.50-3092.00] mL/day vs. 1069.00 [722.00-1486.75] mL/day, p < 0.001) and had more positive daily net intake and output (mean [SD], 1,235.06 [1303.14] mL/day vs. 313.17 [744.75] mL/day, p = 0.012), lower [HbO₂] and [HbT] over the three-day measurement (analyzed by GEE p = 0.01 and 0.043, respectively) and significantly higher [H₂O] on the third day than on the first two days (analyzed by GEE p = 0.034 and 0.018, respectively). Overall, serum VEGF levels were significantly negatively correlated with [HbO₂] and [HbT] (rho = - 0.246 and - 0.266, p = 0.042 and 0.027, respectively) but positively correlated with [H₂O] (rho = 0.449, p < 0.001). Subgroup analysis revealed a significant correlation between serum VEGF and [H2O] in oliguric patients (rho = 0.532, p = 0.003). Multiple regression analysis determined the independent effect of serum VEGF on [H₂O] (standardized coefficient = 0.281, p = 0.038).

CONCLUSIONS

In severe sepsis, oliguria relates to higher positive fluid balance, lower tissue perfusion and oxygenation, and progressive tissue fluid accumulation. Elevated serum VEGF is associated with worsening tissue perfusion and oxygenation and independently affects tissue fluid accumulation.

Decreased VEGFA alleviates the symptoms of LPS-induced sepsis in a mouse model by inhibiting glycolysis and thereby regulating the polarization of macrophages

The immune imbalance caused by excessive inflammatory reactions is the primary cause of sepsis. Macrophages with M1 and M2 polarization states are important immune cells that regulate the balance of the inflammatory response in sepsis. Encouraging the conversion of macrophages from the M1 to the M2 type is an important strategy for relieving sepsis. Here, we demonstrated the upregulation of vascular endothelial growth factor A (VEGFA) in a mouse model of sepsis. Then, siRNA technology was applied to inhibit the expression of VEGFA in macrophages. Flow cytometry and RT‒qPCR results showed that low expression of VEGFA inhibited LPS-induced M1 polarization of macrophages. Decreased VEGFA was also proven to lower TNF-α, IL-1β, and IL-6 secretion by LPS-induced macrophages. In addition, the effects of knocking down VEGFA on the energy metabolism pattern of macrophages were investigated by glycolysis pressure tests and mitochondrial pressure tests, and VEGFA knockdown reversed the induction of glycolysis in macrophages by LPS. The mitochondrial content and ATP content results also confirmed this finding. After the tail vein of septic mice was injected with macrophages transfected with si-VEGFA, the liver and kidney damage and the pathological conditions of the lung were alleviated. The secretion of TNF-α and IL-6 was decreased, while IL-10 was increased in their serum. Immunohistochemical staining revealed decreased expression of CD86 and increased expression of CD206 in the si-VEGFA group. This study demonstrates that decreased VEGFA inhibits glycolysis and thus inhibits LPS-induced M1 polarization of macrophages, ultimately relieving sepsis.

VEGF-Mediated Augmentation of Autophagic and Lysosomal Activity in Endothelial Cells Defends against Intracellular Streptococcus pyogenes

Group A Streptococcus (GAS), a deleterious human-pathogenic bacterium, causes life-threatening diseases such as sepsis and necrotic fasciitis. We recently reported that GAS survives and replicates within blood vessel endothelial cells because these cells are intrinsically defective in xenophagy. Because blood vessel endothelial cells are relatively germfree environments, specific stimulation may be required to sufficiently induce xenophagy. Here, we explored how vascular endothelial growth factor (VEGF) promoted xenophagy and lysosomal activity in endothelial cells. These effects were achieved by amplifying the activation of TFEB, a transcriptional factor crucial for lysosome/autophagy biogenesis, via cAMP-mediated calcium release. In a mouse model of local infection with GAS, the VEGF level was significantly elevated at the infection site. Interestingly, low serum VEGF levels were found in a mouse model of invasive bacteremia and in patients with severe GAS-induced sepsis. Moreover, the administration of VEGF improved the survival of GAS-infected mice. We propose a novel theory regarding GAS infection in endothelial cells, wherein VEGF concentrations in the systemic circulation play a critical role. IMPORTANCE Sepsis caused by Streptococcus pyogenes is a life-threatening condition. Blood vessel endothelial cells should serve as a barrier to infection, although we recently reported that endothelial cells allow intracellular GAS proliferation due to defective xenophagy. In this study, we revealed that administration of VEGF augmented both xenophagy and lysosomal activity in these cells, leading to the efficient killing of intracellular GAS. By comparison, the opposite relationship was observed in vivo, as low serum VEGF concentrations were accompanied by high-severity sepsis in both a mouse model and in human patients. Administration of VEGF reduced mortality in the GAS sepsis model. Based on these findings, we hypothesize that during acute infection, strong VEGF stimulation boosts the intracellular defense system of the endothelium to provide a stronger blood vessel barrier, thereby helping to prevent bacterial dissemination.

Prognostic role of elevated VEGF in sepsis: A systematic review and meta-analysis

Background: The incidence and mortality of sepsis are increasing year by year, and there is still a lack of specific biomarkers to predict its prognosis. Prognostic value of vascular endothelial growth factor (VEGF) in predicting the severity and mortality of sepsis has been gradually discovered. Methods: Literature was searched through Embase, PubMed, Web of Science, China National Knowledge Infrastructure(CNKI) and Cochrane Library databases in March 2022. Observational studies, evaluating the impact of VEGF in sepsis outcomes (mortality and severity) are included in this meta-analysis. Risk of bias was assessed with the Newcastle-Ottawa Scale (NOS). Sensitivity and publication bias analyses were also assessed. Meta-regression analysis were performed to identify the potential sources of heterogeneity. Result: A total of 1,574 articles were retrieved from the systematic literature search. We included 20 studies for qualitative and quantitative analysis. Deceased and critically ill patients had higher baseline VEGF levels than survivors and non-severe patients. The pooled sensitivity and specificity for VEGF predicts sepsis mortality were 0.79and 0.76, respectively. the area under the SROC curve was 0.83. Conclusion: High VEGF are associated with poor clinical outcomes for patients diagnosed with sepsis. This study was recorded on PROSPERO, under the registration ID: CRD42022323079.

The rs8506 TT Genotype in lincRNA-NR_024015 Contributes to the Risk of Sepsis in a Southern Chinese Child Population

Background

Sepsis is a highly life-threatening heterogeneous syndrome and a global health burden. Studies have shown that many genetic variants could influence the risk of sepsis. Long non-coding RNA lincRNA-NR_024015 may participate in functional alteration of endothelial cell via vascular endothelial growth factor (VEGF) signaling, whereas its relevance between the lincRNA-NR_024015 polymorphism and sepsis susceptibility is still unclear.

Methods

474 sepsis patients and 678 healthy controls were enrolled from a southern Chinese child population in the present study. The polymorphism of rs8506 in lincRNA-NR_024015 was determined using Taqman methodology.

Results

Overall, a significant association was found between rs8506 polymorphism and the risk of sepsis disease (TT vs. CC/CT: adjusted OR = 1.751, 95%CI = 1.024–2.993, P = 0.0406). In the stratified analysis, the results suggested that the carriers of TT genotypes had a significantly increased sepsis risk among the children aged 12–60 months, females, early-stage sepsis and survivors (TT vs. CC/CT: OR_age = 2.413; OR_female = 2.868; OR_sepsis = 2.533; OR_survivor = 1.822; adjusted for age and gender, P < 0.05, respectively).

Conclusion

Our study indicated that lincRNA-NR_024015 rs8506 TT genotype might contribute to the risk of sepsis in a southern Chinese child population. Future research is required to elucidate the possible immunoregulatory mechanisms of this association and advance the development of novel biomarkers in sepsis.

Biomarkers Predicting Tissue Pharmacokinetics of Antimicrobials in Sepsis: A Review

The pathophysiology of sepsis alters drug pharmacokinetics, resulting in inadequate drug exposure and target-site concentration. Suboptimal exposure leads to treatment failure and the development of antimicrobial resistance. Therefore, we seek to optimize antimicrobial therapy in sepsis by selecting the right drug and the correct dosage. A prerequisite for achieving this goal is characterization and understanding of the mechanisms of pharmacokinetic alterations. However, most infections take place not in blood but in different body compartments. Since tissue pharmacokinetic assessment is not feasible in daily practice, we need to tailor antibiotic treatment according to the specific patient’s pathophysiological processes. The complex pathophysiology of sepsis and the ineffectiveness of current targeted therapies suggest that treatments guided by biomarkers predicting target-site concentration could provide a new therapeutic strategy. Inflammation, endothelial and coagulation activation markers, and blood flow parameters might be indicators of impaired tissue distribution. Moreover, hepatic and renal dysfunction biomarkers can predict not only drug metabolism and clearance but also drug distribution. Identification of the right biomarkers can direct drug dosing and provide timely feedback on its effectiveness. Therefore, this might decrease antibiotic resistance and the mortality of critically ill patients. This article fills the literature gap by characterizing patient biomarkers that might be used to predict unbound plasma-to-tissue drug distribution in critically ill patients. Although all biomarkers must be clinically evaluated with the ultimate goal of combining them in a clinically feasible scoring system, we support the concept that the appropriate biomarkers could be used to direct targeted antibiotic dosing.

A deadly capillary leak attack. Clarkson's disease: a narrative review

A previously 42-year-old healthy man was brought in by an ambulance to the emergency department with symptoms of a distributive shock. He experienced a rapid decline in his clinical state that evolved into a cardiac arrest. Despite all the performed measures and a prolonged resuscitation, the patient died a few hours later without an initial clear diagnosis. Lab results showed an extremely high haemoconcentration leading to further investigations which suggested the possibility of Clarkson's disease, although septic shock as an alternative diagnosis could not be excluded. Nevertheless, because of its presentation, especially emergency and intensive care physicians should be aware of the existence of this condition in the event of an unexplained refractory distributive shock in combination with haemoconcentration and hypoalbuminemia given its possible fatal outcome.

Growth factor expression is enhanced and extracellular matrix proteins are depressed in healing skin wounds in septic patients compared with healthy controls

Sepsis manifests as a dysregulated immune response to infection, damaging organs. Skin has a critical role in protecting the body. In sepsis, skin wound healing is impaired. The mechanisms behind it have been poorly studied. In this study, suction blister wounds were induced on intact abdominal skin in 15 septic patients. A single blister wound was biopsied from each patient and from 10 healthy controls. Immunohistochemical staining of growth factors and extracellular matrix (ECM) proteins was performed. Significance (p < 0.05) of the differences was calculated. The following growth factors were overexpressed in the skin of septic patients compared with healthy controls: epithelial growth factor (intact epithelium p = 0.007, migrating epithelium p = 0.038), vascular epithelial growth factor (intact epithelium p < 0.001, migrating epithelium p = 0.011) and transforming growth factor beta (migrating epithelium p = 0.002). The expression of syndecan‐1 was upregulated in the skin of septic patients compared with healthy controls (intact epithelium p = 0.048, migrating epithelium p = 0.028). The following ECM proteins had lower expression in the epithelium in septic patients than in healthy controls: tenascin‐C (migrating epithelium p = 0.03) and laminin‐332 (intact epithelium p = 0.036). In sepsis, growth factor and syndecan expression was enhanced, while ECM and basement membrane proteins were mostly depressed.

Detectable A Disintegrin and Metalloproteinase With Thrombospondin Motifs-1 in Serum Is Associated With Adverse Outcome in Pediatric Sepsis

Supplemental Digital Content is available in the text.

A Disintegrin and Metalloproteinase with Thrombospondin Motifs-1 is hypothesized to play a role in the pathogenesis of invasive infection, but studies in sepsis are lacking.

The use of serum endothelial adhesion molecules in pediatric patients with leukemia with febrile neutropenia to predict bacteremia

OBJECTIVE

Febrile neutropenia (FN) represents a life-threatening complication in hematological malignancies. We aimed to analyze the utility of soluble vascular cell adhesion molecule 1 (sVCAM-1), intercellular adhesion molecule 1 (sICAM-1), vascular endothelial growth factor (VEGF) levels compared with C-reactive protein (CRP) and procalcitonin (PCT) during febrile neutropenia episodes of pediatric patients with leukemia.

METHODS

Two plasma samples, on day 0 (initial of episode) and day 3 (48-72 h after episode), for VCAM-1, ICAM-1 and VEGF, CRP and PCT were prospectively collected concomitantly during each febrile neutropenic episode between December 2016 and December 2017. The primary outcome was bacteremia and the secondary outcome was intensive care unit (ICU) admission.

RESULTS

Twenty-two (28.6%) acute lymphoblastic lymphoma (ALL), seventeen (22.1%) acute myeloblastic lymphoma (AML) patients and thirty-eight (49.3%) control patients with no known underlying disease or fever were included in this study. Of the 39 patients; 16 (41%) had bacteremia. Mean serum sVCAM1 and sICAM1 levels were significantly higher in control group, compared to FN patients (p < 0.001). Mean serum sVCAM2 level was significantly higher in FN patients with bacteremia compared to FN patients without bacteremia (144.97 ± 70.35 pg/mL vs 85.45 ± 53.76 pg/mL, p = 0.022). Mean sVCAM1 and 2 levels were higher in FN patients with ICU admission. In this study, we found that sVCAM-1 and VEGF, when combined to CRP and PCT, could predict gram-negative bacteremia in FN episodes of pediatric hematological malignancy.

CONCLUSION

Serum endothelial adhesion molecules, excluding sVCAM-1, cannot predict bacteremia and ICU admission alone in FN patients; but may be associated with clinical outcome when used with PCT and CRP.

Role of epithelial-endothelial cell interaction in the pathogenesis of SARS-CoV-2 infection

Background

The coronavirus disease 2019 (COVID-19) pandemic caused by the novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) continues to threaten public health globally. Patients with severe COVID-19 disease progress to acute respiratory distress syndrome, with respiratory and multiple organ failure. It is believed that dysregulated production of proinflammatory cytokines and endothelial dysfunction contribute to the pathogenesis of severe diseases. However, the mechanisms of SARS-CoV-2 pathogenesis and the role of endothelial cells are poorly understood.

Methods

Well-differentiated human airway epithelial cells were used to explore cytokine and chemokine production after SARS-CoV-2 infection. We measured the susceptibility to infection, immune response, and expression of adhesion molecules in human pulmonary microvascular endothelial cells (HPMVECs) exposed to conditioned medium from infected epithelial cells. The effect of imatinib on HPMVECs exposed to conditioned medium was evaluated.

Results

We demonstrated the production of interleukin-6, interferon gamma-induced protein-10, and monocyte chemoattractant protein-1 from the infected human airway cells after infection with SARS-CoV-2. Although HPMVECs did not support productive replication of SARS-CoV-2, treatment of HPMVECs with conditioned medium collected from infected airway cells induced an upregulation of proinflammatory cytokines, chemokines, and vascular adhesion molecules. Imatinib inhibited the upregulation of these cytokines, chemokines, and adhesion molecules in HPMVECs treated with conditioned medium.

Conclusions

We evaluated the role of endothelial cells in the development of clinical disease caused by SARS-CoV-2 and the importance of endothelial cell–epithelial cell interaction in the pathogenesis of human COVID-19 diseases.

ICU Admission Levels of Endothelial Biomarkers as Predictors of Mortality in Critically Ill COVID-19 Patients

Endotheliopathy is suggested to be an important feature of COVID-19 in hospitalized patients. To determine whether endotheliopathy is involved in COVID-19-associated mortality, markers of endothelial damage were assessed in critically ill COVID-19 patients upon intensive care unit (ICU) admission. Thirty-eight critically ill COVID-19 patients were included in this observational study, 10 of whom died in the ICU. Endothelial biomarkers, including soluble (s)E-selectin, sP-selectin, angiopoietin 1 and 2 (Ang-1 and Ang-2, respectively), soluble intercellular adhesion molecule 1 (sICAM-1), vascular endothelial growth factor (VEGF), soluble vascular endothelial (VE)-cadherin, and von Willebrand factor (vWf), were measured upon ICU admission. The ICU cohort was subsequently divided into survivors and non-survivors; Kaplan-Meier analysis was used to explore associations between biomarkers and survival, while receiver operating characteristic (ROC) curves were generated to determine their potential prognostic value. sE-selectin, sP-selectin, Ang-2, and sICAM-1 were significantly elevated in ICU non-survivors compared to survivors, and also associated with a higher mortality probability in the Kaplan-Meier analysis. The prognostic values of sE-selectin, Ang-2, and sICAM-1 from the generated ROC curves were greater than 0.85. Hence, we conclude that in our cohort, ICU non-survivors had higher levels of specific endothelial markers compared to survivors. Elevated levels of these markers upon ICU admission could possibly predict mortality in COVID-19.

Vascular Endothelial Growth Factor and Soluble Vascular Endothelial Growth Factor Receptor as Novel Biomarkers for Poor Outcomes in Children With Severe Sepsis and Septic Shock

Vascular endothelial growth factor (VEGF) and its receptor, soluble fms-like tyrosine kinase (sFLT), are biomarkers of endothelial activation. Vascular endothelial growth factor and sFLT have been associated with sepsis severity among adults, but pediatric data are lacking. The goal of this study was to assess VEGF and sFLT as predictors of outcome for children with sepsis.

METHODS

Biomarkers measured for each patient at time of presentation to the emergency department were compared in children with septic shock versus children with sepsis without shock. For children with septic shock, the associations between biomarker levels and clinical outcome measures, including intensive care unit and hospital length of stay, vasoactive inotrope score, and measures of organ dysfunction, were assessed.

RESULTS

Soluble fms-like tyrosine kinase and VEGF were elevated in children with septic shock (n = 73) compared with those with sepsis (n = 93). Elevated sFLT but not VEGF was associated with longer intensive care unit length of stay (P = 0.003), longer time requiring vasoactive agents (P < 0.001), higher maximum vasoactive inotrope score (P < 0.001), and higher maximum pediatric logistic organ dysfunction score (P < 0.001).

CONCLUSIONS

Vascular endothelial growth factor and sFLT measured in the emergency department are elevated in children with septic shock, and elevated sFLT but not VEGF is associated with worse clinical outcomes.

Protective Mechanism of the Selective Vasopressin V1A Receptor Agonist Selepressin against Endothelial Barrier Dysfunction

Sepsis and septic shock are among the most common causes of death in the intensive care unit; advanced therapeutic approaches are thus urgently needed. Vascular hyperpermeability represents a major manifestation of severe sepsis and is responsible for the ensuing organ dysfunction and failure. Vasopressin V_1A receptor (V_1AR) agonists have shown promise in the treatment of sepsis, increasing blood pressure, and reducing vascular hyperpermeability. The effects of the selective V_1AR-selective agonist selepressin have been investigated in an in vitro model of thrombin-, vascular endothelial growth factor-, angiopoietin 2-, and lipopolysaccharide (LPS)-induced pulmonary microvascular endothelial hyperpermeability. Results suggest that selepressin counteracts the effects of all four endothelial barrier disruptors in a concentration-dependent manner, as reflected in real-time measurements of vascular permeability by means of transendothelial electrical resistance. Further, selepressin protected the barrier integrity against the LPS-mediated corruption of the endothelial monolayer integrity, as captured by VE-cadherin and actin staining. The protective effects of selepressin were abolished by silencing of the vasopressin V_1AR, as well as by atosiban, an antagonist of the human V_1AR. p53 appears to be involved in mediating these palliative effects, since selepressin strongly induced its expression levels, suppressed the inflammatory RhoA/myosin light chain2 pathway, and triggered the barrier-protective effects of the GTPase Rac1. We conclude that V_1AR-selective agonists, such as selepressin, may prove useful in the improvement of endothelial barrier function in the management of severe sepsis. SIGNIFICANCE STATEMENT: A cardinal sign of sepsis, a serious disease with significant mortality and no specific treatment, is pulmonary endothelial barrier dysfunction that leads to pulmonary edema. Here, we present evidence that in cultured human lung microvascular endothelial cells, the synthetic, selective vasopressin V_1A receptor agonist selepressin protects against endothelial barrier dysfunction caused by four different edemogenic agents, suggesting a potential role of selepressin in the clinical management of sepsis.

Evaluation of COVID-19 coagulopathy; laboratory characterization using thrombin generation and nonconventional haemostasis assays

INTRODUCTION

Patients with COVID-19 are known to have a coagulopathy with a thrombosis risk. It is unknown whether this is due to a generalized humoral prothrombotic state or endothelial factors such as inflammation and dysfunction. The aim was to further characterize thrombin generation using a novel analyser (ST Genesia, Diagnostica Stago, Asnières, France) and a panel of haematological analytes in patients with COVID-19.

METHODS

Platelet poor plasma of 34 patients with noncritical COVID-19 was compared with 75 patients with critical COVID-19 (as defined by WHO criteria) in a retrospective study by calibrated automated thrombography and ELISA. Patients were matched for baseline characteristics of age and gender.

RESULTS

Critical patients had significantly increased fibrinogen, CRP, interleukin-6 and D-dimer compared to noncritical patients. Thrombin generation, in critical patients, was right shifted without significant differences in peak, velocity index or endogenous thrombin potential. Tissue plasminogen activator (tPA), tissue factor pathway inhibitor (TFPI) and vascular endothelial growth factor (VEGF) were significantly increased in the critical versus noncritical patients. Critically ill patients were on haemodiafiltration (31%; heparin used in the circuit) or often received escalated prophylactic low-molecular weight heparin.

CONCLUSION

These results confirm increased fibrinogen and D-dimer in critical COVID-19-infected patients. Importantly, disease severity did not increase thrombin generation (including thrombin-antithrombin complexes and prothrombin fragment 1 + 2) when comparing both cohorts; counter-intuitively critical patients were hypocoaguable. tPA, TFPI and VEGF were increased in critical patients, which are hypothesized to reflect endothelial dysfunction and/or contribution of heparin (which may cause endothelial TFPI/tPA release).

The Diagnostic and Prognostic Role of Vascular Endothelial Growth Factor C in Sepsis and Septic Shock

Introduction

Variations in the expression of vascular endothelial growth factor (VEGF) could be used as a biomarker in critically ill patients with sepsis and septic shock. Inflammation potently upregulates VEGF-C expression via macrophages with an unpredictable response. This study aimed to assess one of the newer biomarkers (VEGF-C) in patients with sepsis or septic shock and its clinical value as a diagnostic and prognostic tool.

Material and methods

The study involved 142 persons divided into three groups. Group A consisted of fifty-eight patients with sepsis; Group B consisted of forty-nine patients diagnosed as having septic shock according to the Sepsis -3 criteria. A control group of thirty-five healthy volunteers comprised Group C. Severity scores, prognostic score and organ dysfunction score, were recorded at the time of enrolment in the study. The analysis included specificity and sensitivity of plasma VEGF-C for diagnosis of septic shock. Circulating plasma VEGF-C levels were correlated with the APACHE II, MODS and severity scores and mortality.

Results

The mean (SD) plasma VEGF-C levels in septic shock patients (1374(789) pg./m), on vasopressors at the time of admission to the ICU, were significantly higher 1374(789)pg./mL, compared the mean (SD) plasma VEGF-C levels in sepsis patients (934(468) pg./mL); (p = 0.0005, Student's t-test.) Plasma VEGF-C levels in groups A and B were shown to be significantly correlated with the APACHE II (r = 0.21, p = 0.02; r = 0.45, p = 0.0009) and MODS score (r = 0.29, p = 0.03; r = 0.4, p = 0.003). There was no association between plasma VEGF-C levels and mortality [p = 0.1]. The cut-off value for septic shock was 1010 pg./ml.

Conclusions

VEGF-C may be used as a prognostic marker in sepsis and septic shock due to its correlation with APACHE II values and as an early marker to determine the likelihood of developing MODS. It could be used as an early biomarker for diagnosing patients with septic shock.

Cellular Stress and General Pathological Processes

From the viewpoint of the general pathology, most of the human diseases are associated with a limited number of pathogenic processes such as inflammation, tumor growth, thrombosis, necrosis, fibrosis, atrophy, pathological hypertrophy, dysplasia and metaplasia. The phenomenon of chronic low-grade inflammation could be attributed to non-classical forms of inflammation, which include many neurodegenerative processes, pathological variants of insulin resistance, atherosclerosis, and other manifestations of the endothelial dysfunction. Individual and universal manifestations of cellular stress could be considered as a basic element of all these pathologies, which has both physiological and pathophysiological significance. The review examines the causes, main phenomena, developmental directions and outcomes of cellular stress using a phylogenetically conservative set of genes and their activation pathways, as well as tissue stress and its role in inflammatory and para-inflammatory processes. The main ways towards the realization of cellular stress and its functional blocks were outlined. The main stages of tissue stress and the classification of its typical manifestations, as well as its participation in the development of the classical and non-classical variants of the inflammatory process, were also described. The mechanisms of cellular and tissue stress are structured into the complex systems, which include networks that enable the exchange of information with multidirectional signaling pathways which together make these systems internally contradictory, and the result of their effects is often unpredictable. However, the possible solutions require new theoretical and methodological approaches, one of which includes the transition to integral criteria, which plausibly reflect the holistic image of these processes.

Increased mobilization of mesenchymal stem cells in patients with acute respiratory distress syndrome undergoing extracorporeal membrane oxygenation

Background

The acute respiratory distress syndrome (ARDS) is characterized by pulmonary epithelial and endothelial barrier dysfunction and injury. In severe forms of ARDS, extracorporeal membrane oxygenation (ECMO) is often the last option for life support. Endothelial progenitor (EPC) and mesenchymal stem cells (MSC) can regenerate damaged endothelium and thereby improve pulmonary endothelial dysfunction. However, we still lack sufficient knowledge about how ECMO might affect EPC- and MSC-mediated regenerative pathways in ARDS. Therefore, we investigated if ECMO impacts EPC and MSC numbers in ARDS patients.

Methods

Peripheral blood mononuclear cells from ARDS patients undergoing ECMO (n = 16) and without ECMO support (n = 12) and from healthy volunteers (n = 16) were isolated. The number and presence of circulating EPC and MSC was detected by flow cytometry. Serum concentrations of vascular endothelial growth factor (VEGF) and angiopoietin 2 (Ang2) were determined.

Results

In the ECMO group, MSC subpopulations were higher by 71% compared to the non-ECMO group. Numbers of circulating EPC were not significantly altered. During ECMO, VEGF and Ang2 serum levels remained unchanged compared to the non-ECMO group (p = 0.16), but Ang2 serum levels in non-survivors of ARDS were significantly increased by 100% (p = 0.02) compared to survivors.

Conclusions

ECMO support in ARDS is specifically associated with an increased number of circulating MSC, most likely due to enhanced mobilization, but not with a higher numbers of EPC or serum concentrations of VEGF and Ang2.

Prognostic value of endothelial biomarkers in refractory cardiogenic shock with ECLS: a prospective monocentric study

BACKGROUND

Extracorporeal membrane oxygenation (ECMO) is often used in critical patients with severe myocardial failure. However, the mortality rate of patients on ECMO is often high. Recent studies have suggested that endothelial activation with subsequent vascular barrier breakdown is a critical pathogenic mechanism of organ damage and is related to the outcome of critical illness. This study aimed to determine whether endothelial biomarkers can be served as prognostic factors for the outcome of patients on ECMO.

METHODS

This prospective study enrolled 23 critically ill patients on veno-arterial ECMO in the intensive care units of a tertiary care hospital between March 2014 and February 2015. Serum samples were tested for thrombomodulin, angiopoietin (Ang)-1, Ang-2, and vascular endothelial growth factor (VEGF). Demographic, clinical, and laboratory data were also collected.

RESULTS

The overall mortality rate was 56.5%. The combination of Ang-2 at the time of ECMO support (day 0) and VEGF at day 2 had the ability to discriminate mortality (area under receiver operating characteristic curve [AUROC], 0.854; 95% confidence interval: 0.645-0.965).

CONCLUSIONS

In this study, we found that the combination of Ang-2 at day 0 and VEGF at day 2 was a modest model for mortality discrimination in this group of patients.

Evaluation of plasma angiopoietin-2 and vascular endothelial growth factor in healthy dogs and dogs with systemic inflammatory response syndrome or sepsis

Background

Angiopoietin‐2 (Ang‐2) and vascular endothelial growth factor (VEGF) are regulators of endothelial permeability.

Objective

Plasma concentrations of Ang‐2 and VEGF are increased in dogs with systemic inflammatory response syndrome (SIRS) and sepsis and are correlated with disease severity and outcome.

Animals

Healthy dogs (n = 18) and client‐owned dogs with SIRS (n = 34) or sepsis (n = 25).

Methods

Prospective observational study. Ang‐2 and VEGF concentrations in admission plasma samples were compared between healthy dogs and dogs with SIRS or sepsis, and between survivors and non‐survivors. Correlations with the acute patient physiologic and laboratory evaluation (APPLE_fast) disease severity score were examined.

Results

Median Ang‐2 was significantly higher in dogs with SIRS (19.3; interquartile range [IQR]: 8.6‐25.7 ng/mL) and sepsis (21.2; IQR: 10.3‐30.1 ng/mL) compared to healthy dogs (7.6; IQR: 6.7‐9.8 ng/mL). Ang‐2 was significantly higher in non‐survivors (24.1; IQR: 11.9‐50.0 ng/mL) than survivors (10.2; IQR: 7.2‐21.5 ng/mL) but did not correlate with the APPLE_fast score. Admission Ang‐2 predicted negative outcome in dogs with SIRS and sepsis with reasonable accuracy (area under the curve [AUC]: 0.75, confidence interval [CI]: 0.59‐0.85; sensitivity: 0.5, CI: 0.29‐0.71; specificity: 0.87, CI: 0.75‐0.95); differentiation between sepsis and SIRS was poor (AUC: 0.58). Plasma VEGF was significantly higher in dogs with sepsis (45; IQR: 14‐107.5 pg/mL) than in dogs with SIRS (3.3; IQR: 0‐35.6 pg/mL) or healthy dogs (0; IQR: 0 pg/mL; P = 0.008). VEGF was significantly (P = .0004) higher in non‐survivors (34.5; IQR: 0‐105.7 pg/mL) than in survivors (0; IQR: 0‐55.2 pg/mL). The ability of VEGF to predict a negative outcome was poor.

Conclusions and Clinical Importance

Ang‐2 may represent a useful additional prognostic marker in dogs with SIRS.

Clinical characteristics and prognosis of serous body cavity effusions in patients with sepsis: a retrospective observational study

Background

Cavity effusion is common in patients with infectious diseases. However, the incidence rate and characteristics of serous cavity effusions (SCE) in septic patients are not clear to date. The objective of this study was to investigate the incidence and characteristics of SCE in septic patients and to explore the correlations between the bloody effusions and the illness severity/prognosis in septic patients.

Methods

From January 2010 to January 2015, a total of 214 patients with severe sepsis and septic shock were enrolled in this retrospective observational study. Thoracentesis or abdominal paracentesis was performed in 45 septic patients because of massive pleural effusions or ascites. The serum concentrations of VEGF, VEGFR, Ang, sICAM-1, sVCAM-1, E-selectin, Serpine1 and VE-cadherin in 45 septic patients underwent paracentesis were measured by enzyme-linked immunosorbent assay (ELISA).

Results

Of the 214 septic patients, 155 (72.4%) had SCE according to imaging or ultrasound manifestations. 45 subjects with SCE underwent therapeutic thoracentesis or abdominal paracentesis. Effusion laboratory analysis showed that exudates were predominant when compared with transudates (95.6% vs. 4.4%), and 16 (35.6%) patients suffered bloody effusions. Compared with patients with non-bloody effusions, those with bloody effusions showed higher critical illness scores (13 vs. 17 for APACHE II; 7 vs. 9 for SOFA), and higher mortality (6.9% vs. 62.5%). Moreover, patients with bloody effusions had delayed TT and APTT, increased D-dimer concentration, and higher serum levels of CRP and PCT (P < 0.05). In addition, the serum levels of Ang2, sVCAM-1 and E-selectin were significantly higher in patients with bloody effusions than in those with non-bloody effusions (P < 0.05). However, the serum level of VEGFR2 was lower in patients with bloody fluids (P = 0.025).

Conclusions

The incidence of serous cavity effusion is high in patients with sepsis. The septic patients with bloody effusions suffer a more inflammatory burden and a worse prognosis compared to septic patients with non-bloody effusions.

Soluble Fms-Like Tyrosine Kinase-1 Is A Marker of Endothelial Dysfunction During Sepsis

Background

Sepsis is currently defined as a life-threatening organ dysfunction caused by a deregulated host response to infection. There is increasing evidence that the endothelium plays a crucial and pathogenic role in sepsis. Profound alterations of the endothelium associated with sepsis include increased leucocytes adhesions, shift to a procoagulant state, vasodilatation, altered barrier function with more permeable capillaries and tissue edema. The vascular endothelial growth factor (VEGF) pathway is involved in the control of microvascular permeability and has been involved in the pathogenesis of conditions associated with endothelial barrier disruption such as sepsis. sFlt-1 is a soluble variant of the VEGF receptor (Fms-like tyrosine kinase-1, Flt-1 or VEGFR-1) able to down-regulate the effects of VEGF by decreasing its signaling. We investigated the possible involvement of sFlt-1 as biomarker of endothelial alteration during sepsis, organ dysfunction and death.

Methods

Serum levels of s-Flt1 were measured in 170 hospitalized patients (77 with sepsis, confirmed by positive blood culture), and in 18 healthy volunteers. The sequential organ failure assessment (SOFA) score was determined by using biochemical and clinical parameters. In a small number of patients (9 individuals), s-Flt1 concentration was evaluated after negativization of the blood culture.

Results

Serum level of s-Flt1 was significantly higher in septic patients than blood culture-negative patients (277.7 ± 52.7 and 133.4 ± 12.4 pg/mL, respectively, P = 0.0088), both groups of patients had significantly higher concentration of sFlt-1 than healthy individuals (78.9 ± 2.5 pg/mL). Among sepsis cases, 68% was caused by Gram-negative bacteria, 27% by Gram-positive bacteria and 8% by Candida species. Serum level of s-Flt1 showed a significant difference between Gram-negative (274.1 pg/mL) and Gram-positive (145.7 pg/mL) sepsis. SOFA score (evaluated in 20 patients with sFlt-1 >190 pg/mL) showed a positive trend of correlation with the increasing sFlt-1 level. After blood culture negativization, serum level of sFlt-1 decreased (37%).

Conclusion

Our findings confirm, in a larger population of patients with sepsis, recent evidences that sFlt-1 levels are higher in patients with complicated-sepsis that evolve to septic shock and suggest that sFlt-1 could be a useful biomarker for sepsis severity. An anti-VEGF effect mediated by sFlt-1 could be hypothesized as salvage compensatory mechanism activated in response to sepsis.

VCAM-1 expression is upregulated by CD34+/CD133+-stem cells derived from septic patients

CD34⁺/CD133⁺- cells are a bone marrow derived stem cell population, which presumably contain vascular progenitor cells and are associated with improved vascular repair. In this study, we investigated whether the adhesion molecules ICAM-1 (intercellular adhesion molecule-1), VCAM-1 (vascular adhesion molecule-1), E-selectin und L-selectin, which are involved in homing of vascular stem cells, are upregulated by CD34⁺/CD133⁺-stem cells from septic patients and would be associated with improved clinical outcome. Peripheral blood mononuclear cells from intensive care unit (ICU) patients with (n = 30) and without sepsis (n = 10), and healthy volunteers (n = 15) were isolated using Ficoll density gradient centrifugation. The expression of VCAM-1, ICAM-1, E-selectin and L-selectin was detected on CD34⁺/CD133⁺-stem cells by flow cytometry. The severity of disease was assessed by the Simplified Acute Physiology Score (SAPS) II. Serum concentrations of vascular endothelial growth factor (VEGF) and angiopoietin (Ang)-2 were determined by Enzyme-linked immunosorbent assay. The expression of VCAM-1, ICAM-1, E-selectin and L-selectin by CD34⁺/CD133⁺-stem cells was significantly upregulated in septic patients, and correlated with sepsis severity. Furthermore, high expression of VCAM-1 by CD34⁺/CD133⁺-stem cells revealed a positive association with mortalitiy (p<0.05). Furthermore, significantly higher serum concentrations of VEGF and Ang-2 were found in septic patients, however none showed a strong association with survival. Our data suggest, that VCAM-1 upregulation on CD34⁺/CD133⁺-stem cells could play a crucial role in their homing in the course of sepsis. An increase in sepsis severity resulted in both and increase in CD34⁺/CD133⁺-stem cells and VCAM-1-expression by those cells, which might reflect an increase in need for vascular repair.

The effects of ozone on bacterial growth and thiol-disulphide homeostasis in vascular graft infection caused by MRSA in rats

Purpose:

To investigate the microbiological, inflammatory and oxidant effects of adjuvant ozone administration in experimental rat vascular graft infection model which has not been previously investigated.

Methods:

Forty adult Wistar rats were divided into Sham, Control, Vancomycin, Ozone, Vancomycin+Ozone groups. Grafts were inoculated with Methicillin-resistant Staphylococcus aureus (MRSA) strain and implanted subcutaneously. Rats were treated intraperitoneally with ozone and /or intramuscularly with vancomycin for 10 days. Grafts were evaluated by quantitative bacterial cultures. Blood samples were harvested for determination of thiol-disulphide and cytokine profiles.

Results:

There was no significant difference in bacterial counts between Control and Ozone Groups. In the Ozone Group median colony count was significantly higher than the Vancomycin and Vancomycin+Ozone Groups. Total thiol and disulphide levels increased and disulphide/native thiol and disulphide/total thiol ratios decreased in Ozone Group significantly. Albumin levels decreased significantly in Vancomycin and Vancomycin+Ozone Groups compared to the Sham Group. IL-1 and TNF-alpha levels significantly increased in infected rats. Decreased levels of VEGF due to infection reversed by ozone therapy in control and vancomycin groups.

Conclusions:

We didn't observe any benefit of the agent on MRSA elimination in our model. Likewise, effects of ozone on thiol-disulphide homeostasis and inflammatory cytokines were contradictory.

Endothelial Permeability and Hemostasis in Septic Shock: Results From the ProCESS Trial

BACKGROUND

We studied patients from the Protocolized Care in Early Septic Shock (ProCESS) trial to determine the effects of alternative resuscitation strategies on circulating markers of endothelial cell permeability and hemostasis and the association between biomarkers and mortality.

METHODS

This was a prospective study of biomarkers of endothelial cell permeability (vascular endothelial growth factor [VEGF], soluble fms-like tyrosine kinase 1 [sFLT-1], angiopoietin 2 [Ang-2]) and biomarkers of hemostasis (von Willebrand factor [vWF], thrombomodulin [TM], tissue plasminogen activator [tPA] in 605 of the 1,341 ProCESS participants in a derivation cohort and 305 participants in a validation cohort. Analyses assessed (1) the impact of varying resuscitation strategies on biomarker profiles and (2) the association of endothelial biomarkers with 60-day in-hospital mortality. The study was conducted in 31 US EDs in adult patients with septic shock. Patients were randomly assigned to one of three resuscitation strategies. Blood samples were collected at enrollment, at 6 h, and at 24 h.

RESULTS

There were 116 (19.2%) and 52 (17.0%) deaths in the derivation and validation cohorts, respectively. There was no significant association between treatment strategy and any biomarker levels. Permeability (Ang-2 and sFLT-1) and hemostasis (vWF, TM, tPA) biomarkers were higher and VEGF levels were lower in nonsurvivors (P < .05 for all). At baseline, sFLT-1 had the highest point estimate for mortality discrimination (derivation area under the curve [AUC], 0.74; validation, 0.70), similar to lactate (AUC, 0.74) and Sequential Organ Failure Assessment score (AUC, 0.73). In an analysis including all time points and adjusted for age, presence of cancer, and Charlson comorbidity score, the adjusted AUC for sFLT-1 was 0.80.

CONCLUSIONS

We found no relationship between different resuscitation strategies and biomarker profiles in sepsis, but we did find that elevated levels of endothelial cell biomarkers of permeability and hemostasis were associated with increased mortality.

TRIAL REGISTRY

ClinicalTrials.gov; No.: NCT00510835 and NCT00793442; URL: www.clinicaltrials.gov.

Blister fluid and serum cytokine levels in severe sepsis in humans reflect skin dysfunction

BACKGROUND

Knowledge of sepsis-related end-organ inflammation in vivo is limited. We investigated the cytokine response in skin and in serum in sepsis and its relation to multiorgan failure (MOF) and survival.

METHODS

Cytokines were analysed in serum and in suction blister fluid of intact skin of 44 patients with severe sepsis and 15 healthy controls. Blister fluid and serum samples were collected within 48 h of the first sepsis-induced organ failure. This is a substudy of a larger follow-up study on wound healing in sepsis.

RESULTS

Cytokine levels were higher in patients with sepsis vs. controls (interleukin [IL]-10, blisters: 65.9 vs. 4.3 pg/ml, P < 0.001, serum: 25.7 vs. 4.5 pg/ml, P = 0.004; IL-6, blisters: 41.9 vs. 0.03 pg/ml, P < 0.001, serum: 45.5 vs. 2.1 pg/ml, P < 0.001). Patients with MOF had higher levels of IL-10 (116.4 vs. 21.3 pg/ml, P = 0.015), IL-4 (0.7 vs. 0.07 pg/ml, P = 0.013) and basic fibroblast growth factor (bFGF) (25.9 vs. 9.5 pg/ml, P = 0.027) in blister fluid than patients without MOF. In blister fluid, survivors had lower levels of IL-10 (43.3 vs. 181.9 pg/ml, P = 0.024) and bFGF (15.8 vs. 31.9 pg/ml, P = 0.006) than non-survivors. In serum, survivors had higher levels of vascular endothelial growth factor (VEGF) (152.2 vs. 14.7 pg/ml, P = 0.012) and lower levels of IL-6 (38.5 vs. 91.1 pg/ml, P = 0.011) than non-survivors. The blister fluid levels of bFGF, TNF and VEGF did not correlate with the serum levels.

CONCLUSIONS

Cytokine responses in skin blister fluid in patients with sepsis differed from those in healthy controls.

Endothelial adhesion molecules and multiple organ failure in patients with severe sepsis

OBJECTIVE

To determine if serum levels of endothelial adhesion molecules were associated with the development of multiple organ failure (MOF) and in-hospital mortality in adult patients with severe sepsis.

DESIGN

This study was a secondary data analysis of a prospective cohort study.

SETTING

Patients were admitted to two tertiary intensive care units in San Antonio, TX, between 2007 and 2012.

PATIENTS

Patients with severe sepsis at the time of intensive care unit (ICU) admission were enrolled. Inclusion criteria were consistent with previously published criteria for severe sepsis or septic shock in adults. Exclusion criteria included immunosuppressive medications or conditions.

INTERVENTIONS

None.

MEASUREMENTS

Baseline serum levels of the following endothelial cell adhesion molecules were measured within the first 72h of ICU admission: Intracellular Adhesion Molecule 1 (ICAM-1), Vascular Cell Adhesion Molecule-1 (VCAM-1), and Vascular Endothelial Growth Factor (VEGF). The primary and secondary outcomes were development of MOF (⩾2 organ dysfunction) and in-hospital mortality, respectively.

MAIN RESULTS

Forty-eight patients were enrolled in this study, of which 29 (60%) developed MOF. Patients that developed MOF had higher levels of VCAM-1 (p=0.01) and ICAM-1 (p=0.01), but not VEGF (p=0.70) compared with patients without MOF (single organ failure only). The area under the curve (AUC) to predict MOF according to VCAM-1, ICAM-1 and VEGF was 0.71, 0.73, and 0.54, respectively. Only increased VCAM-1 levels were associated with in-hospital mortality (p=0.03). These associations were maintained even after adjusting for APACHE and SOFA scores using logistic regression.

CONCLUSIONS

High levels of serum ICAM-1 was associated with the development of MOF. High levels of VCAM-1 was associated with both MOF and in-hospital mortality.

Network Analysis of Human Genes Influencing Susceptibility to Mycobacterial Infections

Tuberculosis and nontuberculous mycobacterial infections constitute a high burden of pulmonary disease in humans, resulting in over 1.5 million deaths per year. Building on the premise that genetic factors influence the instance, progression, and defense of infectious disease, we undertook a systems biology approach to investigate relationships among genetic factors that may play a role in increased susceptibility or control of mycobacterial infections. We combined literature and database mining with network analysis and pathway enrichment analysis to examine genes, pathways, and networks, involved in the human response to Mycobacterium tuberculosis and nontuberculous mycobacterial infections. This approach allowed us to examine functional relationships among reported genes, and to identify novel genes and enriched pathways that may play a role in mycobacterial susceptibility or control. Our findings suggest that the primary pathways and genes influencing mycobacterial infection control involve an interplay between innate and adaptive immune proteins and pathways. Signaling pathways involved in autoimmune disease were significantly enriched as revealed in our networks. Mycobacterial disease susceptibility networks were also examined within the context of gene-chemical relationships, in order to identify putative drugs and nutrients with potential beneficial immunomodulatory or anti-mycobacterial effects.

Is VEGF a marker of severity of scrub typhus infection?

Vascular endothelial growth factor (VEGF) and its receptors have been reported as severity markers of septicemia. Scrub typhus (ST) results in multi-organ dysfunction but the role of VEGF has not been evaluated. We report VEGF and its receptors in ST and its correlation with severity, outcome and laboratory findings. Thirty patients with ST diagnosed by solid phase immune chromatographic assay and Weil-Felix tests were included. Their clinical details, Glasgow Coma Scale (GCS), SOFA and modified Rankin Scale (mRS) scores and laboratory findings were noted. VEGF, VEGFR1 and VEGFR2 were done by ELISA at admission and repeated at 1 month. Outcome was defined at 1 month. Serum VEGF and VEGF-R1 levels were significantly higher and VEGFR2 was significantly lower in the ST patients compared to the controls. These levels significantly improved at 1 month. VEGF level correlated with SOFA score (p = 0.05) and SGPT (p = 0.04). VEGFR1 correlated with hemoglobin (p = 0.04), platelet count (p = 0.03), serum CK (p = 0.001), weakness (p = 0.04) and mRS score (p = 0.04). VEGFR2 did not correlate with any clinical or laboratory parameters. All the patients recovered with doxycycline. Serum VEGF and VEGFR1 levels increased in ST and suggest disease severity but do not predict outcome.

Host response biomarkers in the diagnosis of sepsis: a general overview

Critically ill patients who display a systemic inflammatory response syndrome (SIRS) are prone to develop nosocomial infections. The challenge remains to distinguish as early as possible among SIRS patients those who are developing sepsis. Following a sterile insult, damage-associated molecular patterns (DAMPs) released by damaged tissues and necrotic cells initiate an inflammatory response close to that observed during sepsis. During sepsis, pathogen-associated molecular patterns (PAMPs) trigger the release of host mediators involved in innate immunity and inflammation through identical receptors as DAMPs. In both clinical settings, a compensatory anti-inflammatory response syndrome (CARS) is concomitantly initiated. The exacerbated production of pro- or anti-inflammatory mediators allows their detection in biological fluids and particularly within the bloodstream. Some of these mediators can be used as biomarkers to decipher among the patients those who developed sepsis, and eventually they can be used as prognosis markers. In addition to plasma biomarkers, the analysis of some surface markers on circulating leukocytes or the study of mRNA and miRNA can be helpful. While there is no magic marker, a combination of few biomarkers might offer a high accuracy for diagnosis.

Novel relationships between oxidative stress and angiogenesis-related factors in sepsis: New biomarkers and therapies

Sepsis is a systemic uncontrolled inflammatory response in the presence of an infection. It remains a major cause of morbidity and mortality in hospitalized patients. According to its severity, sepsis can progress to three different states: severe sepsis, septic shock, and multiple organ dysfunction syndrome, related to organ dysfunction and/or tissue hypoperfusion. Different processes underlie its pathophysiology; among them are oxidative stress, endothelial and mitochondrial dysfunction, and angiogenesis-related factors. However, no studies have integrated these elements in sepsis. The main difficulty in sepsis is its diagnosis. Currently, the potential of inflammatory biomarkers in septic patients remains weak. In this context, the research into new biomarkers is essential to aid with sepsis diagnosis and prognostication. Furthermore, even though the current management of severe forms of sepsis has been effective, morbimortality remains elevated. Therefore, it is essential to explore alternative approaches to therapy development. The aim of this review is to present an update of evidence supporting the role of oxidative stress and angiogenesis-related factors in the pathophysiology of the different forms of sepsis. It proposes a novel convergence between both elements in their role in the disease, and it will cover their utility as new diagnostic tools, predictors of outcome, and as novel therapeutic targets.

Elevated biomarkers of endothelial dysfunction/activation at ICU admission are associated with sepsis development

Widespread endothelial activation and dysfunction often precede clinical sepsis. Several endothelium-related molecules have been investigated as potential biomarkers for early diagnosis and/or prognosis of sepsis, providing different results depending on study designs. Such factors include endothelial adhesion molecules like E- and P-selectin, and the intercellular adhesion molecule-1, vascular endothelial cadherin, growth factors such as Angiopoietin-1 and -2 and vascular endothelial growth factor, as well as von Willebrand factor antigen. We sought to investigate whether circulating biomarkers of endothelial activation/dysfunction measured at ICU admission are associated with subsequent sepsis development. Eighty-nine critically-ill patients admitted to a general ICU who met no sepsis criteria were studied. Plasma or serum levels of the above-mentioned endothelium-derived molecules were measured during the first 24h post ICU; acute physiology and chronic health evaluation (APACHE) II and sequential organ failure assessment (SOFA) scores, age, sex, diagnostic category, and circulating procalcitonin (PCT) and C-reactive protein (CRP) levels were additionally measured or recorded. Forty-five patients subsequently became septic and 44 did not. Soluble (s) E- and P-selectin levels, circulating PCT, SOFA score and diagnostic category were significantly different between the two groups. Multiple logistic regression analysis associated elevated sE- and sP-selectin levels and SOFA with an increased risk of developing sepsis, while multiple Cox regression analysis identified sE- and sP-selectin levels as the only parameters related to sepsis appearance with time [RR=1.026, 95%CI=1.008-1.045, p=0.005; RR=1.005 (by 10 units), 95%CI=1.000-1.010, p=0.034, respectively]. When trauma patients were independently analyzed, multiple Cox regression analysis revealed sE-selectin to be the only molecule associated with sepsis development with time (RR=1.041, 95%CI: 1.019-1.065; p<0.001). In conclusion, in our cohort of initially non-septic critically-ill patients, high levels of the circulating endothelial adhesion molecules E- and P-selectin, measured at ICU admission, appear to be associated with sepsis development in time.

Sublingual microcirculation is impaired in post-cardiac arrest patients

AIM

We hypothesized that microcirculatory dysfunction, similar to that seen in sepsis, occurs in post-cardiac arrest patients and that better microcirculatory flow will be associated with improved outcome. We also assessed the association between microcirculatory dysfunction and inflammatory markers in the post-cardiac arrest state.

METHODS

We prospectively evaluated the sublingual microcirculation in post-cardiac arrest patients, severe sepsis/septic shock patients, and healthy control patients using Sidestream Darkfield microscopy. Microcirculatory flow was assessed using the microcirculation flow index (MFI) at 6 and 24h in the cardiac arrest patients, and within 6h of emergency department admission in the sepsis and control patients.

RESULTS

We evaluated 30 post-cardiac arrest patients, 16 severe sepsis/septic shock patients, and 9 healthy control patients. Sublingual microcirculatory blood flow was significantly impaired in post-cardiac arrest patients at 6h (MFI 2.6 [IQR: 2-2.9]) and 24h (2.7 [IQR: 2.3-2.9]) compared to controls (3.0 [IQR: 2.9-3.0]; p<0.01 and 0.02, respectively). After adjustment for initial APACHE II score, post-cardiac arrest patients had significantly lower MFI at 6-h compared to sepsis patients (p<0.03). In the post-cardiac arrest group, patients with good neurologic outcome had better microcirculatory blood flow as compared to patients with poor neurologic outcome (2.9 [IQR: 2.4-3.0] vs. 2.6 [IQR: 1.9-2.8]; p<0.03). There was a trend toward higher median MFI at 24h in survivors vs. non-survivors (2.8 [IQR: 2.4-3.0] vs. 2.6 [IQR: 2.1-2.8] respectively; p<0.09). We found a negative correlation between MFI-6 and vascular endothelial growth factor (VEGF) (r=-0.49, p=0.038). However, after Bonferroni adjustment for multiple comparisons, this correlation was statistically non-significant.

CONCLUSION

Microcirculatory dysfunction occurs early in post-cardiac arrest patients. Better microcirculatory function at 24h may be associated with good neurologic outcome.

The dynamics of angiogenic factors and their soluble receptors in relation to organ dysfunction in disseminated intravascular coagulation associated with sepsis

We prospectively studied (1) the relationships between angiogenic factors, their soluble receptors and organ dysfunction and (2) the effects of disseminated intravascular coagulation (DIC)-induced platelet consumption, thrombin generation, and tissue hypoxia on the expression of the factors and receptors. Fifty patients with sepsis were classified into two subgroups: 37 patients with DIC and 13 patients without DIC. DIC patients showed higher Sequential Organ Failure Assessment (SOFA) scores, the prevalence of multiple organ dysfunction syndrome (MODS) and more increased soluble fibrin and lactate levels. We observed lower levels of vascular endothelial growth factor (VEGF), soluble VEGF receptor 2 (sVEGFR2), angiopoietin 1 (Ang1) and Ang1/Ang2, and higher sVEGFR1 and Ang2 levels in DIC patients, but not significant differences in soluble Tie2 expression during the study period. The levels of VEGF, sVEGFR1, and Ang2 in DIC patients correlated with the SOFA scores. Clear differences were observed in the levels of Ang2 in the DIC patients between survivors and nonsurvivors and between those with and without MODS. The area under receiver operating characteristic curves for predicting death and MODS by Ang2 were 0.710 and 0.784, respectively. The VEGF levels showed a marked correlation with the platelet counts. Soluble fibrin and lactate levels independently predicted increases in the levels of VEGF, sVEGFR1, and Ang2 in DIC patients. In conclusion, VEGF, sVEGFR1, Ang2, and Ang1/Ang2, especially Ang2, may have roles in the development of MODS in sepsis associated with DIC, and VEGF, sVEGFR1, and Ang2 serum levels correlated with the extent of DIC-induced platelet consumption, thrombin generation, and blood lactate levels.

Early biomarker activity in severe sepsis and septic shock and a contemporary review of immunotherapy trials: not a time to give up, but to give it earlier

Improving time to diagnosis and intervention has positively impacted outcomes in acute myocardial infarction, stroke, and trauma through elucidating the early pathogenesis of those diseases. This insight may partly explain the futility of time-insensitive immunotherapy trials for severe sepsis and septic shock. The aim of this study was to examine the early natural history of circulatory biomarker activity in sepsis, relative to previous animal and human outcome trials. We conducted a literature search using PubMed, MEDLINE, and Google Scholar to identify outcome trials targeting biomarkers with emphasis on the timing of therapy. These findings were compared with the biomarker activity observed over the first 72 h of hospital presentation in a cohort of severe sepsis and septic shock patients. Biomarker levels in animal and human research models are elevated within 30 min after exposure to an inflammatory septic stimulus. Consistent with these findings, the biomarker cascade is activated at the most proximal point of hospital presentation in our patient cohort. These circulatory biomarkers overlap; some have bimodal patterns and generally peak between 3 and 36 h while diminishing over the subsequent 72 h of observation. When this is taken into account, prior outcome immunotherapy trials have generally enrolled patients after peak circulatory biomarker concentrations. In previous immunotherapy sepsis trials, intervention was delayed after the optimal window of peak biomarker activity. As a result, future studies need to recalibrate the timing of enrollment and administration of immunotherapy agents that still may hold great promise for this deadly disease.

Biomarkers of endothelial activation/dysfunction in infectious diseases

Endothelial dysfunction contributes to the pathogenesis of a variety of potentially serious infectious diseases and syndromes, including sepsis and septic shock, hemolytic-uremic syndrome, severe malaria, and dengue hemorrhagic fever. Because endothelial activation often precedes overt endothelial dysfunction, biomarkers of the activated endothelium in serum and/or plasma may be detectable before classically recognized markers of disease, and therefore, may be clinically useful as biomarkers of disease severity or prognosis in systemic infectious diseases. In this review, the current status of mediators of endothelial cell function (angiopoietins-1 and -2), components of the coagulation pathway (von Willebrand Factor, ADAMTS13, and thrombomodulin), soluble cell-surface adhesion molecules (soluble E-selectin, sICAM-1, and sVCAM-1), and regulators of vascular tone and permeability (VEGF and sFlt-1) as biomarkers in severe infectious diseases is discussed in the context of sepsis, E. coli O157:H7 infection, malaria, and dengue virus infection.

Using angiogenic factors and their soluble receptors to predict organ dysfunction in patients with disseminated intravascular coagulation associated with severe trauma

Introduction

Disseminated intravascular coagulation (DIC) is characterized by the concomitant activation of coagulofibrinolytic disorders and systemic inflammation associated with endothelial dysfunction-induced microvascular permeability. Angiogenic factors, including vascular endothelial growth factor (VEGF), angiopoietin (Ang), and their receptors, play crucial roles in angiogenesis and microvascular permeability. The aim of the study was to assess the relationship between angiogenic factors, their soluble receptors and organ dysfunction associated with DIC after severe trauma.

Materials and methods

A total of 57 patients with severe trauma were divided into two subgroups; 30 DIC patients and 27 non-DIC patients. The DIC was diagnosed based on the Japanese Association for Acute Medicine (JAAM) DIC and the International Society on Thrombosis and Haemostasis (ISTH) overt DIC criteria. The serum levels of angiogenic factors were measured at the time of admission (Day 1), Day 3 and Day 5. This study compared levels of these angiogenic factors between the two DIC groups, and evaluated their predictive value for organ dysfunction.

Results

DIC patients, especially those with ISTH DIC, showed higher Sequential Organ Failure Assessment (SOFA) scores and lactate levels. There were lower levels of VEGF, Ang1 and the soluble Tie2 in the ISTH DIC patients than the non-DIC patients. The levels of soluble VEGF receptor-1 (sVEGFR1), Ang2 and the Ang2/Ang1 ratio in the ISTH DIC patients were higher than in non-DIC patients. The relationship between the presence of massive transfusion and angiogenic factors indicated the same results. The levels of sVEGFR1, Ang2 and the Ang2/Ang1 ratio correlated with the SOFA scores. In particular, sVEGFR1 and Ang2 were independent predictors of an increase in the SOFA score. The lactate levels independently predicted increases in the levels of sVEGFR1 and Ang2. The decrease in the platelet counts also independently predicted the increase in Ang2 levels in DIC patients.

Conclusions

Angiogenic factors and their soluble receptors, particularly sVEGFR1 and Ang2, are considered to play pivotal roles in the development of organ dysfunction in DIC associated with severe trauma. DIC-induced tissue hypoxia and platelet consumption may play crucial roles in inducing sVEGFR1 and Ang2, and in determining the prognosis of the severity of organ dysfunction.

Angiogenic factors and their soluble receptors predict organ dysfunction and mortality in post-cardiac arrest syndrome

INTRODUCTION

Post-cardiac arrest syndrome (PCAS) often leads to multiple organ dysfunction syndrome (MODS) with a poor prognosis. Endothelial and leukocyte activation after whole-body ischemia/reperfusion following resuscitation from cardiac arrest is a critical step in endothelial injury and related organ damage. Angiogenic factors, including vascular endothelial growth factor (VEGF) and angiopoietin (Ang), and their receptors play crucial roles in endothelial growth, survival signals, pathological angiogenesis and microvascular permeability. The aim of this study was to confirm the efficacy of angiogenic factors and their soluble receptors in predicting organ dysfunction and mortality in patients with PCAS.

METHODS

A total of 52 resuscitated patients were divided into two subgroups: 23 survivors and 29 non-survivors. The serum levels of VEGF, soluble VEGF receptor (sVEGFR)1, sVEGFR2, Ang1, Ang2 and soluble Tie2 (sTie2) were measured at the time of admission (Day 1) and on Day 3 and Day 5. The ratio of Ang2 to Ang1 (Ang2/Ang1) was also calculated. This study compared the levels of angiogenic factors and their soluble receptors between survivors and non-survivors, and evaluated the predictive value of these factors for organ dysfunction and 28-day mortality.

RESULTS

The non-survivors demonstrated more severe degrees of organ dysfunction and a higher prevalence of MODS. Non-survivors showed significant increases in the Ang2 levels and the Ang2/Ang1 ratios compared to survivors. A stepwise logistic regression analysis demonstrated that the Ang2 levels or the Ang2/Ang1 ratios on Day 1 independently predicted the 28-day mortality. The receiver operating characteristic curves of the Ang2 levels, and the Ang2/Ang1 ratios on Day 1 were good predictors of 28-day mortality. The Ang2 levels also independently predicted increases in the Sequential Organ Failure Assessment (SOFA) scores.

CONCLUSIONS

We observed a marked imbalance between Ang1 and Ang2 in favor of Ang2 in PCAS patients, and the effect was more prominent in non-survivors. Angiogenic factors and their soluble receptors, particularly Ang2 and Ang2/Ang1, are considered to be valuable predictive biomarkers in the development of organ dysfunction and poor outcomes in PCAS patients.

Prognostic value of chromogranin A in severe sepsis: data from the FINNSEPSIS study

PURPOSE

To assess the prognostic information of chromogranin A (CgA), a marker associated with adrenergic tone and myocardial function, in patients with severe sepsis.

METHODS

CgA levels were measured at the time of study inclusion and 72 h later in 232 patients with severe sepsis recruited from 24 ICUs in Finland (FINNSEPSIS study).

RESULTS

Sixty-five patients (28%) died during the index hospitalization. CgA levels at inclusion and after 72 h correlated with several established indices of risk in sepsis. Patients who died during the hospitalization had higher baseline CgA levels than hospital survivors: 14.0 (Q1-3, 7.4-27.4) versus 9.1 (5.9-15.8) nmol/l, P = 0.002, and after 72 h: 16.2 (9.0-31.1) versus 9.8 (6.0-18.0) nmol/l, P = 0.001. Prior cardiovascular disease (P = 0.04) and cardiovascular SOFA levels on day 3 (P = 0.03) were associated with higher CgA levels after 72 h by linear regression. CgA levels on study inclusion and after 72 h were independently associated with hospital mortality by logistic regression: OR (logarithmically transformed CgA levels) 1.95 (95% CI 1.01-3.77), P = 0.046 and OR 2.03 (95% CI 1.18-3.49), P = 0.01, respectively. The prognostic accuracy was comparable for CgA measurements and SAPS II score, and the addition of CgA measurements to the SAPS II score improved risk stratification of the patients as assessed by the category-free net reclassification index. A CgA level >6.6 nmol/l on study inclusion was associated with septic shock during the hospitalization.

CONCLUSION

CgA levels measured during hospitalization for severe sepsis are associated with cardiovascular dysfunction and may provide additional prognostic information in patients with severe sepsis.

Clinical utility of biomarkers of endothelial activation in sepsis--a systematic review

INTRODUCTION

A strong biologic rationale exists for targeting markers of endothelial cell (EC) activation as clinically informative biomarkers to improve diagnosis, prognostic evaluation or risk-stratification of patients with sepsis.

METHODS

The objective was to review the literature on the use of markers of EC activation as prognostic biomarkers in sepsis. MEDLINE was searched for publications using the keyword 'sepsis' and any of the identified endothelial-derived biomarkers in any searchable field. All clinical studies evaluating markers reflecting activation of ECs were included. Studies evaluating other exogenous mediators of EC dysfunction and studies of patients with malaria and febrile neutropenia were excluded.

RESULTS

Sixty-one studies were identified that fulfilled the inclusion criteria. Overall, published studies report positive correlations between multiple EC-derived molecules and the diagnosis of sepsis, supporting the critical role of EC activation in sepsis. Multiple studies also reported positive associations for mortality and severity of illness, although these results were less consistent than for the presence of sepsis. Very few studies, however, reported thresholds or receiver operating characteristics that would establish these molecules as clinically-relevant biomarkers in sepsis.

CONCLUSIONS

Multiple endothelial-derived molecules are positively correlated with the presence of sepsis in humans, and variably correlated to other clinically-important outcomes. The clinical utility of these biomarkers is limited by a lack of assay standardization, unknown receiver operating characteristics and lack of validation. Additional large-scale prospective clinical trials will be required to determine the clinical utility of biomarkers of endothelial activation in the management of patients with sepsis.

Biomarkers of endothelial dysfunction: can they help us deciphering systemic inflammation and sepsis?

The endothelial integrity, as mechanical barrier against microorganisms and as natural "anticoagulant", is crucial for physiologic organ function. Systemic activation of the endothelium upon inflammation, sepsis, and septic shock is always ending in blood-tissue barrier disruption. With increasing dysfunction, uncontrolled clotting activation, capillary microthrombi formation, tissue edema, local hypoxia, and ischemia are initiated. This in turn enhances a vicious circle leading to multiple organ failure and death. Therefore, biomarkers reflecting this special compartment may help in the early detection of systemic inflammation and its complications. This review provides an overview of the most important endothelial biomarkers and their possible use in sepsis.

Time-course of sFlt-1 and VEGF-A release in neutropenic patients with sepsis and septic shock: a prospective study

Background

Septic shock is the most feared complication of chemotherapy-induced febrile neutropenia. So far, there are no robust biomarkers that can stratify patients to the risk of sepsis complications. The VEGF-A axis is involved in the control of microvascular permeability and has been involved in the pathogenesis of conditions associated with endothelial barrier disruption such as sepsis. sFlt-1 is a soluble variant of the VEGF-A receptor VEGFR-1 that acts as a decoy receptor down-regulating the effects of VEGF-A. In animal models of sepsis, sFlt-1 was capable to block the barrier-breaking negative effects of VEGF-A and to significantly decrease mortality. In non-neutropenic patients, sFlt-1 has been shown to be a promising biomarker for sepsis severity.

Methods

We prospectively evaluated concentrations of sFlt-1 and VEGF-A at different time-points during febrile neutropenia, and evaluated the association of these levels with sepsis severity and septic shock development.

Results

Neutropenic patients that evolved with septic shock (n = 10) presented higher levels of sFlt-1 and VEGF-A measured 48 hours after fever onset than patients with non-complicated sepsis (n = 31) and levels of these biomarkers correlated with sepsis severity scores. Estimation of the diagnostic accuracy of sFlt-1 levels for the discrimination of patients that evolved to septic shock yielded promising results in our study population.

Discussion

Our data suggest that sFlt-1 and VEGF-A could be useful biomarkers for sepsis severity in patients with febrile neutropenia. In addition, the kinetics of sFlt-1 release in patients that evolve to septic shock suggest that the sFlt-1 could be a salvage compensatory mechanism in patients with septic shock, but that the magnitude of the sFlt-1 release observed in human sepsis is not sufficient to reproduce the beneficial anti-VEGF-A effects observed in animal models of sepsis.