Circulating sICAM-1 and sE-Selectin as biomarker of infection and prognosis in patients with systemic inflammatory response syndrome

Beneficial effects of recombinant CER-001 high-density lipoprotein infusion in sepsis: results from a bench to bedside translational research project

BACKGROUND

Sepsis is characterized by a dysregulated immune response and metabolic alterations, including decreased high-density lipoprotein cholesterol (HDL-C) levels. HDL exhibits beneficial properties, such as lipopolysaccharides (LPS) scavenging, exerting anti-inflammatory effects and providing endothelial protection. We investigated the effects of CER-001, an engineered HDL-mimetic, in a swine model of LPS-induced acute kidney injury (AKI) and a Phase 2a clinical trial, aiming to better understand its molecular basis in systemic inflammation and renal function.

METHODS

We carried out a translational approach to study the effects of HDL administration on sepsis. Sterile systemic inflammation was induced in pigs by LPS infusion. Animals were randomized into LPS (n = 6), CER20 (single dose of CER-001 20 mg/kg; n = 6), and CER20 × 2 (two doses of CER-001 20 mg/kg; n = 6) groups. Survival rate, endothelial dysfunction biomarkers, pro-inflammatory mediators, LPS, and apolipoprotein A-I (ApoA-I) levels were assessed. Renal and liver histology and biochemistry were analyzed. Subsequently, we performed an open-label, randomized, dose-ranging (Phase 2a) study included 20 patients with sepsis due to intra-abdominal infection or urosepsis, randomized into Group A (conventional treatment, n = 5), Group B (CER-001 5 mg/kg BID, n = 5), Group C (CER-001 10 mg/kg BID, n = 5), and Group D (CER-001 20 mg/kg BID, n = 5). Primary outcomes were safety and efficacy in preventing AKI onset and severity; secondary outcomes include changes in inflammatory and endothelial dysfunction markers.

RESULTS

CER-001 increased median survival, reduced inflammatory mediators, complement activation, and endothelial dysfunction in endotoxemic pigs. It enhanced LPS elimination through the bile and preserved liver and renal parenchyma. In the clinical study, CER-001 was well-tolerated with no serious adverse events related to study treatment. Rapid ApoA-I normalization was associated with enhanced LPS removal and immunomodulation with improvement of clinical outcomes, independently of the type and gravity of the sepsis. CER-001-treated patients had reduced risk for the onset and progression to severe AKI (stage 2 or 3) and, in a subset of critically ill patients, a reduced need for organ support and shorter ICU length of stay.

CONCLUSIONS

CER-001 shows promise as a therapeutic strategy for sepsis management, improving outcomes and mitigating inflammation and organ damage.

TRIAL REGISTRATION

The study was approved by the Agenzia Italiana del Farmaco (AIFA) and by the Local Ethic Committee (N° EUDRACT 2020-004202-60, Protocol CER-001- SEP_AKI_01) and was added to the EU Clinical Trials Register on January 13, 2021.

MicroRNA-146a negatively regulates inflammation via the IRAK1/TRAF6/NF-κB signaling pathway in dry eye

Inflammation is a key factor in the pathogenesis of dry eye disease (DED). We aimed to investigate the role of microRNA-146a (miR-146a) in regulating corneal inflammation in a mouse model of benzalkonium chloride (BAC)-induced dry eye and the TNF-α-induced NF-κB signaling pathway in human corneal epithelial cells (HCECs). A mouse model of dry eye was established by administering with BAC to BALB/c mice, and the expression of TNF-α, IL-1β, IL-6, IL-8, cyclooxygenase 2 (COX2), interleukin-1 receptor-associated kinase 1 (IRAK1) and TNF receptor-associated factor 6 (TRAF6) in the corneas of dry eye model mice was significantly increased; this was accompanied by the upregulation of miR-146a and activation of the NF-κB pathway. In vitro, TNF-α induced miR-146a expression in HCECs, while the NF-κB inhibitor SC-514 reduced the expression of miR-146a. Overexpression of miR-146a decreased the expression of IRAK1 and TRAF6, which have been identified as targets of miR-146a. Furthermore, overexpression of miR-146a suppressed NF-κB p65 translocation from the cytoplasm to the nucleus. Moreover, overexpression of miR-146a attenuated the TNF-α-induced expression of IL-6, IL-8, COX2 and intercellular adhesion molecule 1 (ICAM1), while inhibition of miR-146a exerted the opposite effect. Our results suggest that miR-146a mediates the inflammatory response in DED. MiR-146a negatively regulates inflammation in HCECs through the IRAK1/TRAF6/NF-κB pathway, and this may serve as a potential therapeutic approach for the treatment of DED.

Chelation Therapy Associated with Antioxidant Supplementation Can Decrease Oxidative Stress and Inflammation in Multiple Sclerosis: Preliminary Results

An imbalance of oxy-inflammation status has been involved in axonal damage and demyelination in multiple sclerosis (MS). The aim of this study was to investigate the efficacy of an antioxidant treatment (calcium disodium ethylenediaminetetracetic acid-EDTA) chelation therapy associated with a micronutrient complex in MS patients. A total of 20 MS patients and 20 healthy subjects, enrolled as a control group (CTR), were recruited. We measured the plasma ROS production and total antioxidant capacity (TAC) by a direct assessment using Electron Paramagnetic Resonance; activities of the antioxidant system (thiols' redox status and enzymes); and the urinary presence of biomarkers of oxidative stress by immunoenzymatic assays. We also evaluated the levels of inflammation by plasmatic cytokines (TNFα, IL-1β, and IL-6) and assessed the sICAM levels, as well as the nitric oxide (NO) catabolism and transthyretin (TTR) concentration. Comparing CTR and MS, in the latter ROS production, oxidative damage, inflammatory biomarkers, and NO metabolite concentrations results were significantly higher, while TAC was significantly lower. Treatment in MS induced significant (p < 0.05) down-regulating of pro-inflammatory sICAM1, TNF-α, IL6, as well as biomarkers of lipid peroxidation and DNA damage production. The protective effect exhibited may occur by decreasing ROS production and increasing antioxidant capacity, turning into a more reduced thiols' status.

Effects of somatostatin in combination with early hemoperfusion on inflammatory, hemorheological and oxidative parameters during the treatment of acute pancreatitis

We aimed to evaluate the effects of somatostatin combined with early hemoperfusion on inflammatory and stress responses during acute pan-creatitis (AP) treatment.A total of 159 AP patients treated from September 2016 to January 2020 were randomly divided into three groups A-C (n=53). In addition to routine treatment, groups A-C were additionally given somatostatin, early hemoperfusion, and somatostatin combined with early hemoperfusion, re-spectively. Their inflammatory factors, stress response, intestinal mucosal bar-rier, hemorheological indices, recovery time, length of stay, clinical efficacy, and adverse reactions were compared. The levels of serum interleukin-10 (IL -10), catalase and glutathione peroxidase rose in the three groups after ten days of treatment, compared with values before treatment, being the highest rise in group C. The levels of IL -18, tumor necrosis factor-α, soluble intercellular adhe-sion molecule-1, procalcitonin, high mobility group protein B1, lipid hydrogen peroxide, advanced oxidation protein products, epinephrine, cortisol, D-lactic acid, diamine oxidase, and endotoxin decreased after ten days of treatment compared with those before treatment, which were lowest in group C (P<0.05). After ten days of treatment, the levels of hemorheological indices were signifi-cantly lower than those before treatment (P<0.05). Compared with groups A and B, group C had a shorter recovery time of urine amylase, bowel sound and passing gas, remission time of abdominal pain, length of stay, and a higher to-tal response rate (P<0.05).During AP treatment, somatostatin combined with early hemoperfusion effectively relieved inflammatory and stress responses, protected the intestinal mucosal barrier function and improved the hemorheol-ogy, thereby promoting the recovery and benefiting the prognosis of patients.

Inflammation-related genes and immune infiltration landscape identified in kainite-induced temporal lobe epilepsy based on integrated bioinformatics analysis

BACKGROUND

Temporal lobe epilepsy (TLE) is a common brain disease. However, the pathogenesis of TLE and its relationship with immune infiltration remains unclear. We attempted to identify inflammation-related genes (IRGs) and the immune cell infiltration pattern involved in the pathological process of TLE via bioinformatics analysis.

MATERIALS AND METHODS

The GSE88992 dataset was downloaded from the Gene Expression Omnibus (GEO) database to perform differentially expressed genes screening and weighted gene co-expression network analysis (WGCNA). Subsequently, the functional enrichment analysis was performed to explore the biological function of the differentially expressed IRGs (DEIRGs). The hub genes were further identified by the CytoHubba algorithm and validated by an external dataset (GSE60772). Furthermore, the CIBERSORT algorithm was applied to assess the differential immune cell infiltration between control and TLE groups. Finally, we used the DGIbd database to screen the candidate drugs for TLE.

RESULTS

34 DEIRGs (33 up-regulated and 1 down-regulated gene) were identified, and they were significantly enriched in inflammation- and immune-related pathways. Subsequently, 4 hub DEIRGs (Ptgs2, Jun, Icam1, Il6) were further identified. Immune cell infiltration analysis revealed that T cells CD4 memory resting, NK cells activated, Monocytes and Dendritic cells activated were involved in the TLE development. Besides, there was a significant correlation between hub DEIRGs and some of the specific immune cells.

CONCLUSION

4 hub DEIRGs (Ptgs2, Jun, Icam1, Il6) were associated with the pathogenesis of TLE via regulation of immune cell functions, which provided a novel perspective for the understanding of TLE.

Immunoregulatory effects of testosterone supplementation combined with exercise training in men with Inclusion Body Myositis: a double-blind, placebo-controlled, cross-over trial

Objectives

Sporadic Inclusion Body Myositis (IBM) is an inflammatory muscle disease affecting individuals over the age of 45, leading to progressive muscle wasting, disability and loss of independence. Histologically, IBM is characterised by immune changes including myofibres expressing major histocompatibility complex molecules and invaded by CD8⁺ T cells and macrophages, and by degenerative changes including protein aggregates organised in inclusion bodies, rimmed vacuoles and mitochondrial abnormalities. There is currently no cure, and regular exercise is currently the only recognised treatment effective at limiting muscle weakening, atrophy and loss of function. Testosterone exerts anti-inflammatory effects, inhibiting effector T-cell differentiation and pro-inflammatory cytokine production.

Methods

We conducted a double-blind, placebo-controlled, cross-over trial in men with IBM, to assess whether a personalised progressive exercise training combined with application of testosterone, reduced the inflammatory immune response associated with this disease over and above exercise alone. To assess intervention efficacy, we immunophenotyped blood immune cells by flow cytometry, and measured serum cytokines and chemokines by Luminex immunoassay.

Results

Testosterone supplementation resulted in modest yet significant count reduction in the classical monocyte subset as well as eosinophils. Testosterone-independent immunoregulatory effects attributed to exercise included altered proportions of some monocyte, T- and B-cell subsets, and reduced IL-12, IL-17, TNF-α, MIP-1β and sICAM-1 in spite of interindividual variability.

Conclusion

Overall, our findings indicate anti-inflammatory effects of exercise training in IBM patients, whilst concomitant testosterone supplementation provides some additional changes. Further studies combining testosterone and exercise would be worthwhile in larger cohorts and longer testosterone administration periods.

Targeting intercellular adhesion molecule-1 (ICAM-1) to reduce rhinovirus-induced acute exacerbations in chronic respiratory diseases

The chronic respiratory non-communicable diseases, asthma and chronic obstructive pulmonary disease (COPD) are among the leading causes of global mortality and morbidity. Individuals suffering from these diseases are particularly susceptible to respiratory infections caused by bacterial and/or viral pathogens, which frequently result in exacerbation of symptoms, lung function decline, frequent hospital emergency visits and increased socioeconomic burden. Human rhinoviruses (HRV) remain the major viral pathogen group implicated in exacerbations of both asthma and COPD. The rhinoviral entry into the host lung epithelium is facilitated primarily by the adhesion site (“receptor”) intercellular adhesion molecule-1 (ICAM-1), coincidentally expressed on the respiratory epithelium in these conditions. Multiple observations of increased airway ICAM-1 protein in asthmatics, smokers and smoking-related COPD have been recorded in the literature. However, the lack of robust therapies for COPD in particular has triggered a renewed interest in assessing receptor antagonism-based anti-viral strategies for treatment of intercurrent viral infections in those with pre-existing chronic lung diseases. Given the crucial role ICAM-1 plays in facilitating HRV adhesion and, thus, transmissibility to the host respiratory system, as well as the up-regulation of ICAM-1 by smoking, we summarize the role of HRV in smoking-induced COPD and especially highlight the role of ICAM-1 in epithelial viral adhesion and chronic lung disease progression. Further, the review also sheds light specifically on evolving precision therapeutic strategies in blocking ICAM-1 for preventing viral adhesion and exacerbations of COPD.

Association of markers of endothelial activation and dysfunction with occurrence and outcome of pulmonary hemorrhage in dogs with leptospirosis

Background

Endothelial dysfunction might contribute to the development of leptospiral pulmonary hemorrhage syndrome (LPHS).

Hypothesis

Serum concentrations of markers of endothelial activation and dysfunction are higher in dogs with leptospirosis and correlate with the occurrence of LPHS and a higher case fatality rate.

Animals

Clinically healthy dogs (n = 31; 10/31 dogs confirmed healthy based on no detected abnormalities on blood work), dogs with leptospirosis with LPHS (n = 17) and without LPHS (n = 15), dogs with acute kidney injury not due to leptospirosis (AKI‐nL, n = 34).

Methods

Observational study. Serum concentrations of soluble intercellular adhesion molecule 1 (sICAM‐1), vascular endothelial growth factor (VEGF), and angiopoietin‐2 (Ang‐2) at admission were compared between groups. Correlations with outcome and the accuracy to predict LPHS were examined.

Results

Soluble intercellular adhesion molecule (sICAM‐1), VEGF, and Ang‐2 concentrations were higher in dogs with AKI‐nL (sICAM‐1 34.7 ng/mL, interquartile range [IQR] = 24.4‐75.5; VEGF 43.1 pg/mL, IQR = 12.3‐79.2; Ang‐2 8.5 ng/mL, IQR = 6.2‐12.3), leptospirosis without LPHS (sICAM‐1 45.1 ng/mL, IQR = 30.6‐59.0; VEGF 32.4 pg/mL, IQR = 12.5‐62.6; Ang‐2 9.6 ng/mL, IQR = 6.9‐19.3), and LPHS (sICAM‐1 69.7 ng/mL, IQR = 42.1‐89.1; VEGF 51.8 pg/mL, IQR = 26.3‐96.7; Ang‐2 8.0 ng/mL, IQR = 5.6‐12.2) compared to controls (P < .001). In dogs with leptospirosis, VEGF and sICAM‐1 were higher in nonsurvivors (sICAM‐1 89.4 ng/mL, IQR = 76.5‐101.0; VEGF 117.0 pg/mL, IQR = 90.3‐232.4) than survivors (P = .004) and sICAM‐1 predicted the development of LPHS.

Conclusions

Soluble intercellular adhesion molecule 1, VEGF, and Ang‐2 do not discriminate leptospirosis from AKI‐nL. In dogs with leptospirosis, sICAM‐1 and VEGF predict outcome and sICAM‐1 might identify dogs at risk for LPHS.

Platelet Microparticles Enriched in miR-223 Reduce ICAM-1-Dependent Vascular Inflammation in Septic Conditions

In the process of sepsis, activated platelets shed microvesicles containing microRNAs (miRNAs), which can be internalized by distinct recipient cells in circulation, consequently eliciting a potent capability to regulate their cellular functions in different diseases. In the present study, activated human platelets transferring miR-223 into endothelial cells via platelet-derived microparticles (PMPs) was investigated in vitro during septic conditions with a proposed mechanism involving in downregulation of the enhanced expression of intercellular adhesion molecule-1 (ICAM-1). The uptake of PMPs encasing miR-223 and the adhesion of peripheral blood mononuclear cells (PBMCs) on human coronary artery endothelial cells (HCAECs) were observed by immunofluorescence microscopy upon co-culture with PMPs isolated from sepsis or control plasma. The expression of miR-223-3p and its gene target ICAM1 in HCAECs were quantified by RT-qPCR and ELISA after the cells were incubated with septic or control PMPs, whose levels were induced with thrombin-receptor activating peptide (TRAP). Leukocyte-depleted platelets (LDPs) from septic patients showed a decreased miR-223 level, while septic plasma and PMPs revealed an elevated miRNA level compared to control samples. Similarly, TRAP-activated LDPs demonstrated a reduced intracellular miR-223 expression, while increased levels in the supernatant and PMP isolates were observed vs. untreated samples. Furthermore, TNF-α alone resulted in decreased miR-223 and elevated ICAM1 levels in HCAECs, while PMPs raised the miRNA level that was associated with downregulated ICAM1 expression at both mRNA and protein levels under TNF-α treatment. Importantly, miR-223 was turned out not to be newly synthesized as shown in unchanged pre-miR-223 level, and mature miR-223 expression was also elevated in the presence of PMPs in HCAECs after transfection with Dicer1 siRNA. In addition, septic PMPs containing miR-223 decreased ICAM1 with a reduction of PBMC binding to HCAECs. In conclusion, septic platelets released PMPs carrying functional miR-223 lower ICAM1 expression in endothelial cells, which may be a protective role against excessive sepsis-induced vascular inflammation.

Prognostic performance of endothelial biomarkers to early predict clinical deterioration of patients with suspected bacterial infection and sepsis admitted to the emergency department

BACKGROUND

The objective of this study was to evaluate the ability of endothelial biomarkers to early predict clinical deterioration of patients admitted to the emergency department (ED) with a suspected sepsis. This was a prospective, multicentre, international study conducted in EDs. Adult patients with suspected acute bacterial infection and sepsis were enrolled but only those with confirmed infection were analysed. The kinetics of biomarkers and organ dysfunction were collected at T0, T6 and T24 hours after ED admission to assess prognostic performances of sVEGFR2, suPAR and procalcitonin (PCT). The primary outcome was the deterioration within 72 h and was defined as a composite of relevant outcomes such as death, intensive care unit admission and/or SOFA score increase validated by an independent adjudication committee.

RESULTS

After adjudication of 602 patients, 462 were analysed including 124 who deteriorated (27%). On admission, those who deteriorated were significantly older (73 [60-82] vs 63 [45-78] y-o, p < 0.001) and presented significantly higher SOFA scores (2.15 ± 1.61 vs 1.56 ± 1.40, p = 0.003). At T0, sVEGFR2 (5794 [5026-6788] vs 6681 [5516-8059], p < 0.0001), suPAR (6.04 [4.42-8.85] vs 4.68 [3.50-6.43], p < 0.0001) and PCT (7.8 ± 25.0 vs 5.4 ± 17.9 ng/mL, p = 0.001) were associated with clinical deterioration. In multivariate analysis, low sVEGFR2 expression and high suPAR and PCT levels were significantly associated with early deterioration, independently of confounding parameters (sVEGFR2, OR = 1.53 [1.07-2.23], p < 0.001; suPAR, OR = 1.57 [1.21-2.07], p = 0.003; PCT, OR = 1.10 [1.04-1.17], p = 0.0019). Combination of sVEGFR2 and suPAR had the best prognostic performance (AUC = 0.7 [0.65-0.75]) compared to clinical or biological variables.

CONCLUSIONS

sVEGFR2, either alone or combined with suPAR, seems of interest to predict deterioration of patients with suspected bacterial acute infection upon ED admission and could help front-line physicians in the triage process.

ICAM-1: A master regulator of cellular responses in inflammation, injury resolution, and tumorigenesis

ICAM-1 is a cell surface glycoprotein and an adhesion receptor that is best known for regulating leukocyte recruitment from circulation to sites of inflammation. However, in addition to vascular endothelial cells, ICAM-1 expression is also robustly induced on epithelial and immune cells in response to inflammatory stimulation. Importantly, ICAM-1 serves as a biosensor to transduce outside-in-signaling via association of its cytoplasmic domain with the actin cytoskeleton following ligand engagement of the extracellular domain. Thus, ICAM-1 has emerged as a master regulator of many essential cellular functions both at the onset and at the resolution of pathologic conditions. Because the role of ICAM-1 in driving inflammatory responses is well recognized, this review will mainly focus on newly emerging roles of ICAM-1 in epithelial injury-resolution responses, as well as immune cell effector function in inflammation and tumorigenesis. ICAM-1 has been of clinical and therapeutic interest for some time now; however, several attempts at inhibiting its function to improve injury resolution have failed. Perhaps, better understanding of its beneficial roles in resolution of inflammation or its emerging function in tumorigenesis will spark new interest in revisiting the clinical value of ICAM-1 as a potential therapeutic target.

Markers of endothelial cell activation in suspected late onset neonatal sepsis in Surinamese newborns: a pilot study

BACKGROUND

Serum levels of markers of endothelial cell activation are associated with bacteremia and mortality in sepsis in adults, children, and newborns with early onset sepsis. We hypothesize that levels of these markers are associated with these outcomes in hospitalized newborns with suspected late onset neonatal sepsis (LONS).

METHODS

In this prospective cohort study, newborns admitted to the tertiary neonatal care facility of Suriname were included upon clinical suspicion of LONS and before start of antibiotic treatment, between April 1, 2015 and May 31, 2016. Serum concentrations of angiopoietin-1, angiopoietin-2, and soluble isoforms of P-selectin, E-selectin, vascular cell adhesion molecule-1 (sVCAM-1), intercellular adhesion molecule-1 (sICAM-1), platelet and endothelial cell adhesion molecule-1 (sPECAM-1), matrix metalloproteinase-9 (MMP-9), neutrophil elastase, and tissue-inhibitor of metalloproteinases-1 (TIMP-1) were measured.

RESULTS

Twenty-thee newborns were included. Baseline characteristics were similar between newborns with and without bacteremia and between non-survivors and survivors. Only soluble E-selectin (sE-selectin) was higher in newborns with bacteremia versus non-bacteremia (P=0.04) and lower in non-survivors (P=0.04). No conclusions could be made for sVCAM-1 due to high serum concentrations.

CONCLUSIONS

In conclusion, the data from this pilot study indicate that serum levels of markers of endothelial cell activation are poorly associated with bacteremia and mortality.

Network of Mediators for Vascular Inflammation and Leakage Is Dysbalanced during Cytoreductive Surgery for Late-Stage Ovarian Cancer

Background

Cytoreductive surgery (CS) in late-stage ovarian cancer patients is often challenging due to extensive volume shifts, and high fluid intake may provoke postoperative complications. Expression of vasoactive mediators is altered in cancer patients, which may affect systemic vascular function. We sought to assess how serum levels of vasoactive markers and mediators change during CS in ovarian cancer.

Methods

Following IRB approval and informed consent, pre- and postoperative serum samples were analyzed in 26 late-stage ovarian cancer patients using multiplex protein arrays and ELISA.

Results

The proinflammatory cytokines and chemokines IL-6, IL-8, and CCL2 were significantly elevated after 24 hrs compared to the baseline values, with IL-6 and IL-8 being most prominently increased. While ANGPT1 remained unchanged after surgery, its competitive antagonist ANGPT2 was significantly increased. In contrast, serum levels of the ANGPT receptor TIE2 were decreased to 0.6 of the baseline values. While VEGF-D, E-selectin, P-selectin, ICAM-1, and PECAM-1 remained unchanged, serum activity of both thrombomodulin and syndecan-1 was significantly increased following surgery.

Conclusion

We identified a regulatory network of acute-phase reaction during CS in late-stage ovarian cancer. This suggests that IL-6 exerts positive regulation of other proinflammatory mediators and, by upregulating ANGPT2 and suppressing ANGPT1, induces a serum profile that promotes vascular leakage. This may contribute to the observed hemodynamic alterations during CS procedures.

Quercetin Inhibits the Production of IL-1β-Induced Inflammatory Cytokines and Chemokines in ARPE-19 Cells via the MAPK and NF-κB Signaling Pathways

Quercetin, a bioflavonoid derived from vegetables and fruits, exerts anti-inflammatory effects in various diseases. Our previous study revealed that quercetin could suppress the expression of matrix metalloprotease-9 (MMP-9) and intercellular adhesion molecule-1 (ICAM-1) to achieve anti-inflammatory effects in tumor necrosis factor-α (TNF-α)-stimulated human retinal pigment epithelial (ARPE-19) cells. The present study explored whether quercetin can inhibit the interleukin-1β (IL-1β)-induced production of inflammatory cytokines and chemokines in ARPE-19 cells. Prior to stimulation by IL-1β, ARPE-19 cells were pretreated with quercetin at various concentrations (2.5–20 µM). The results showed that quercetin could dose-dependently decrease the mRNA and protein levels of ICAM-1, IL-6, IL-8 and monocyte chemoattractant protein-1 (MCP-1). It also attenuated the adherence of the human monocytic leukemia cell line THP-1 to IL-1β-stimulated ARPE-19 cells. We also demonstrated that quercetin inhibited signaling pathways related to the inflammatory process, including phosphorylation of mitogen-activated protein kinases (MAPKs), inhibitor of nuclear factor κ-B kinase (IKK)α/β, c-Jun, cAMP response element-binding protein (CREB), activating transcription factor 2 (ATF2) and nuclear factor (NF)-κB p65, and blocked the translocation of NF-κB p65 into the nucleus. Furthermore, MAPK inhibitors including an extracellular signal-regulated kinase (ERK) 1/2 inhibitor (U0126), a p38 inhibitor (SB202190) and a c-Jun N-terminal kinase (JNK) inhibitor (SP600125) decreased the expression of soluble ICAM-1 (sICAM-1), but not ICAM-1. U0126 and SB202190 could inhibit the expression of IL-6, IL-8 and MCP-1, but SP600125 could not. An NF-κB inhibitor (Bay 11-7082) also reduced the expression of ICAM-1, sICAM-1, IL-6, IL-8 and MCP-1. Taken together, these results provide evidence that quercetin protects ARPE-19 cells from the IL-1β-stimulated increase in ICAM-1, sICAM-1, IL-6, IL-8 and MCP-1 production by blocking the activation of MAPK and NF-κB signaling pathways to ameliorate the inflammatory response.

Validation of two multiplex platforms to quantify circulating markers of inflammation and endothelial injury in severe infection

Biomarkers can prognosticate outcome and enable risk-stratification. In severe infection, focusing on multiple markers reflecting pathophysiological mechanisms of organ injury could enhance management and pathway-directed therapeutics. Limited data exist on the performance of multiplex biomarker platforms. Our goal was to compare endothelial and immune activation biomarkers in severe pediatric infections using two multiplex platforms. Frozen plasma from 410 children presenting to the Jinja Regional Hospital in Uganda with suspected infection was used to measure biomarkers of endothelial (Angiopoietin-2, sFlt-1, sVCAM-1, sICAM-1) and immune (IL-6, IP-10, sTNFR-1, CHI3L1) activation. Two multiplex platforms (Luminex®, Ella^TM) based on monoclonal antibody sandwich immunoassays using biotin-streptavidin conjugate chemistry were selected with reagents from R&D Systems. The two platforms differed in ease and time of completion, number of samples per assay, and dynamic concentration range. Intra-assay variability assessed using a coefficient of variation (CV%) was 2.2–3.4 for Luminex® and 1.2–2.9 for Ella^TM. Correlations for biomarker concentrations within dynamic range of both platforms were best for IL-6 (ρ = 0.96, p<0.0001), IP-10 (ρ = 0.94, p<0.0001) and sFlt-1 (ρ = 0.94, p<0.0001). Agreement between concentrations obtained by both methods assessed by the Bland-Altman test varied, with best agreement for CHI3L1. Our data suggest that biomarkers of endothelial and immune activation can be readily measured with multiplex platforms. Luminex® and Ella^TM produced reliable results with excellent CV% values. The Ella^TM platform was more automated and completed in 75 minutes, potentially compatible with near-patient use. Trends in concentrations obtained by these methods were highly correlated, although absolute values varied, suggesting caution is required when comparing data from different multiplex platforms.

A comparison of the immunological potency of Burkholderia lipopolysaccharides in endotoxemic BALB/c mice

Lipopolysaccharide is one of the virulence factors of the soil-borne pathogens Burkholderia pseudomallei, B. thailandensis, B. cenocepacia and B. multivorans, which cause septic melioidosis (often in B. pseudomallei infections but rarely in B. thailandensis infections) or cepacia syndromes (commonly in B. cenocepacia infections but rarely in B. multivorans infections). The inflammatory responses in Burkholderia LPS-induced endotoxemia were evaluated in this study. Prior to induction, the conserved structures and functions of each purified LPS were determined using electrophoretic phenotypes, the ratios of 3-hydroxytetradecanoic to 3-hydroxyhexadecanoic acid and endotoxin units. In an in vitro assay, cytokine expression of myeloid differentiation primary response gene 88 and Toll/IL-1 receptor domain containing adapter-inducing INF-β-dependent signaling-dependent signaling differed when stimulated by different LPS. Endotoxemia was induced in mice by s.c. injection as evidenced by increasing serum concentrations of 3-hydroxytetradecanoic acid and the septic prognostic markers CD62E and ICAM-1. During endotoxemia, splenic CD11b⁺ I-A⁺ , CD11b⁺ CD80⁺ , CD11b⁺ CD86⁺ and CD11b⁺ CD11c⁺ subpopulations increased. After induction with B. pseudomallei LPS, there were significant increases in splenic CD49b NK cells and CD14 macrophages. The inflamed CD11b⁺ CCR2⁺ , CD11b⁺ CD31⁺ , CD11b⁺ CD14⁺ , resident CD11b⁺ CX₃ CR1⁺ and progenitor CD11b⁺ CD34⁺ cells showed delayed increases in bone marrow. B. multivorans LPS was the most potent inducer of serum cytokines and chemokines, whereas B. cenocepacia LPS induced relatively low concentrations of the chemokines MIP-1α and MIP-1β. Endotoxin activities did not correlate with the virulence of Burkholderia strains. Thus factors other than LPS and/or other mechanisms of low activity LPS must mediate the pathogenicity of highly virulent Burkholderia strains.

Soluble P-selectin as a Biomarker for Infection and Survival in Patients With a Systemic Inflammatory Response Syndrome on the Intensive Care Unit

Aims:

This study investigated the ability of soluble platelet selectin (sP-selectin) to identify infection and predict 30-day mortality in patients with a systemic inflammatory response syndrome (SIRS) on the intensive care unit.

Methods:

Soluble platelet selectin levels were measured daily in the first 48 hours in patients presenting with SIRS. The outcome, proven infection, was established using predefined definitions. The 30-day mortality was retrospectively assessed.

Results:

In a total of 313 patients with SIRS, sP-selectin levels were measured. Of these, 114 patients had proven infection on admission or developing during their intensive care unit (ICU) stay. Patients with proven infection had moderately higher levels of sP-selectin (147 ng/mL; interquartile range [IQR], 93.4-203 ng/mL) compared with noninfected patients (143.8 ng/mL; IQR, 89.6-194.7 ng/mL). This difference was not statistically significant (P = .072). However, in patients who were not admitted for infection (n = 235), sP-selectin levels were significantly related to the subsequent development of infection (P = .013). Soluble platelet selectin levels were particularly high in patients with abdominal sepsis and skin infections. Higher sP-selectin levels were associated with higher mortality (although not statistically significant, P = .08).

Conclusions:

This study shows that in patients with SIRS not admitted for infection, sP-selectin levels are significantly related to the subsequent development of infection. Furthermore, patients with higher sP-selectin levels in the first 2 days of admission had higher 30-day mortality, although this association is not statistically significant. Therefore, we conclude that sP-selectin is a potential future biomarker for both mortality and infection in patients with SIRS, but more research is needed to confirm its prognostic role.

Biomarkers for diagnosis of sepsis in patients with systemic inflammatory response syndrome: a systematic review and meta-analysis

Background

Sepsis is one of the most common diseases that seriously threaten human health. Although a large number of markers related to sepsis have been reported in the last two decades, the diagnostic accuracy of these biomarkers remains unclear due to the lack of similar baselines among studies. Therefore, we conducted a large systematic review and meta-analysis to evaluate the diagnostic value of biomarkers from studies that included non-infectious systemic inflammatory response syndrome patients as a control group.

Methods

We searched Medline, Embase and the reference lists of identified studies beginning in April 2014. The last retrieval was updated in September 2016.

Results

Ultimately, 86 articles fulfilled the inclusion criteria. Sixty biomarkers and 10,438 subjects entered the final analysis. The areas under the receiver operating characteristic curves for the 7 most common biomarkers, including procalcitonin, C-reactive protein, interleukin 6, soluble triggering receptor expressed on myeloid cells-1, presepsin, lipopolysaccharide binding protein and CD64, were 0.85, 0.77, 0.79, 0.85, 0.88, 0.71 and 0.96, respectively. The remaining 53 biomarkers exhibited obvious variances in diagnostic value and methodological quality.

Conclusions

Although some biomarkers displayed moderate or above moderate diagnostic value for sepsis, the limitations of the methodological quality and sample size may weaken these findings. Currently, we still lack an ideal biomarker to aid in the diagnosis of sepsis. In the future, biomarkers with better diagnostic value as well as a combined diagnosis using multiple biomarkers are expected to solve the challenge of the diagnosis of sepsis.

Electronic supplementary material

The online version of this article (doi:10.1186/s40064-016-3591-5) contains supplementary material, which is available to authorized users.

Short and long-term effects of high-dose intravenous methylprednisolone pulse therapy on thyroid-associated ophthalmopathy

The majority of previous studies on high-dose intravenous methylprednisolone pulse (IVMP) therapy have observed the clinical conditions of patients prior to and following treatment without any long-term follow-up, and these studies have predominantly focused on combined treatment. The present prospective clinical study aimed to assess the long-term effects and safety of high-dose IVMP therapy in thyroid-associated ophthalmopathy (TAO), as well as the significance of thyrotropin receptor antibody (TRAb) and soluble intercellular adhesion molecule-l (sICAM-1) during IVMP therapy. A total of 58 patients with TAO were treated with high-dose IVMP therapy, and their clinical characteristics and indices were recorded before, during and after therapy, with a 12-57 month (mean, 28.4 months) follow-up. Before treatment and on the second day after each IVMP therapy, serum TRAb and sICAM-1 levels were evaluated in 23 patients with TAO via a competitive radioimmunoassay and enzyme-linked immunosorbent assay, respectively. The results of the present study demonstrated that the symptoms of eyelid swelling, ophthalmodynia, photophobia, lacrimation and diplopia, and visual acuity, ocular motility, proptosis and clinical activity score (CAS) indices were all significantly improved after IVMP therapy. In addition, analysis of covariance demonstrated that alterations in the levels of serum TRAb during the course of treatment were associated with CAS of TAO, whereas the change in serum sICAM-1 was not. In conclusion, high-dose IVMP therapy is an effective, safe, stable and well-tolerated treatment for TAO, which is associated with rare, minor adverse effects. Furthermore, serum TRAb levels are correlated with the CAS of TAO and may serve as a predictor of the response to methylprednisolone therapy.

Heat stress pretreatment decreases lipopolysaccharide-induced apoptosis via the p38 signaling pathway in human umbilical vein endothelial cells

The present study aimed to investigate vascular endothelial apoptosis, and the regulatory molecules involved in the condition of heatstroke caused by direct hyperthermia due to high core temperature and gut‑derived endotoxemia. Human umbilical vascular endothelial cells (HUVECs) were isolated and treated with heat stress (43˚C for 1 h), lipopolysaccharide (LPS; 1 µg/ml), or a combination of heat stress pretreatment followed by LPS. Caspase‑3 activity, DNA fragmentation, and cell viability, determined using a 3‑(4, 5‑dimethyl thiazol‑2‑yl)‑2,5‑diphenyl tetrazolium bromide assay, were measured to examine cellular apoptosis. Changes in the expression levels of heat shock protein (HSP) 27, HSP90 and B‑cell lymphoma 2 (Bcl‑2), and the phosphorylation of p38 were detected using Western blot assays. The specific inhibitor of p38, SB203580, was also used. LPS induced endothelial apoptosis, as indicated by increased caspase‑3 activity, a high level of DNA fragmentation and low cell viability. LPS also increased p38 phosphorylation and decreased the expression levels of HSP27, HSP90 and Bcl‑2. Heat stress pretreatment inhibited LPS‑induced cellular apoptosis, increased the phosphorylation of p38, and increased the expression levels of HSP27, HSP90 and Bcl‑2. Pretreatment with SB203580 had effects similar to those of heat stress in the amelioration of LPS‑induced effects. These findings demonstrated that heat stress pretreatment decreased LPS‑induced Bcl‑2‑associated apoptosis in HUVECs by attenuating p38 activation, thereby increasing the expression levels of HSP27 and HSP90.

Association Between Intercellular Adhesion Molecule-1, -2, -3 Plasma Levels and Disease Activity of Ankylosing Spondylitis in the Chinese Han Population

STUDY DESIGN

We investigated the association between ICAM-1, -2, -3 plasma levels and ankylosing spondylitis (AS) disease activity.

OBJECTIVE

In the present study, we aimed to investigate the association between ICAM-1, -2, -3 plasma levels and AS disease activity in the Chinese Han population.

SUMMARY OF BACKGROUND DATA

AS is a chronic inflammatory rheumatic disease that effects the sacroiliac joints and axial skeleton. The intercellular adhesion molecules (ICAMs) are members of the immunoglobulin superfamily and have been identified to play major roles in inflammation and immune responses.

METHODS

A total of 60 patients with AS and 60 healthy individuals were selected. The plasma levels of proinflammatory cytokines, including tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), and ICAM-1, -2, -3, were analyzed by ELISA. Disease severity-related indexes, including the Bath ankylosing spondylitis disease activity index (BASDAI), Bath ankylosing spondylitis functional index (BASFI), and ankylosing spondylitis disease activity score (ASDAS), were assessed, along with the erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) level.

RESULTS

Both ICAM-1 and ICAM-2 levels in plasma were markedly increased in AS patients compared with levels in the plasma of controls. There was no difference between controls and patients in term of ICAM-3 levels. Furthermore, in patients, correlation analysis showed that TNF-α and IL-6 production, as well as the ESR and CRP levels, have positive relationships with ICAM-1 and ICAM-2 plasma levels; the BASDAI, BASFI, and ASDAS scores were also found to be positively correlated with ICAM-2. However, no significant correlations between ICAM-1 levels and BASDAI, BASFI, or ASDAS were detected in our study.

CONCLUSION

The current findings suggest that ICAM-2 may be a potential biomarker reflecting disease activity and functional ability in AS patients.

LEVEL OF EVIDENCE

5.

A Dormant Microbial Component in the Development of Preeclampsia

Preeclampsia (PE) is a complex, multisystem disorder that remains a leading cause of morbidity and mortality in pregnancy. Four main classes of dysregulation accompany PE and are widely considered to contribute to its severity. These are abnormal trophoblast invasion of the placenta, anti-angiogenic responses, oxidative stress, and inflammation. What is lacking, however, is an explanation of how these themselves are caused. We here develop the unifying idea, and the considerable evidence for it, that the originating cause of PE (and of the four classes of dysregulation) is, in fact, microbial infection, that most such microbes are dormant and hence resist detection by conventional (replication-dependent) microbiology, and that by occasional resuscitation and growth it is they that are responsible for all the observable sequelae, including the continuing, chronic inflammation. In particular, bacterial products such as lipopolysaccharide (LPS), also known as endotoxin, are well known as highly inflammagenic and stimulate an innate (and possibly trained) immune response that exacerbates the inflammation further. The known need of microbes for free iron can explain the iron dysregulation that accompanies PE. We describe the main routes of infection (gut, oral, and urinary tract infection) and the regularly observed presence of microbes in placental and other tissues in PE. Every known proteomic biomarker of "preeclampsia" that we assessed has, in fact, also been shown to be raised in response to infection. An infectious component to PE fulfills the Bradford Hill criteria for ascribing a disease to an environmental cause and suggests a number of treatments, some of which have, in fact, been shown to be successful. PE was classically referred to as endotoxemia or toxemia of pregnancy, and it is ironic that it seems that LPS and other microbial endotoxins really are involved. Overall, the recognition of an infectious component in the etiology of PE mirrors that for ulcers and other diseases that were previously considered to lack one.

Transgenerational Social Stress, Immune Factors, Hormones, and Social Behavior

A social signal transduction theory of depression has been proposed that states that exposure to social adversity alters the immune response and these changes mediate symptoms of depression such as anhedonia and impairments in social behavior The exposure of maternal rats to the chronic social stress (CSS) of a male intruder depresses maternal care and impairs social behavior in the F1 and F2 offspring of these dams. The objective of the present study was to characterize basal peripheral levels of several immune factors and related hormone levels in the adult F2 offspring of CSS exposed dams and assess whether changes in these factors are associated with previously reported deficits in allogrooming behavior. CSS decreased acid glycoprotein (α1AGP) and intercellular adhesion molecule-1 (ICAM-1) in F2 females, and increased granulocyte macrophage-colony stimulating factor (GM-CSF) in F2 males. There were also sex dependent changes in IL-18, tissue inhibitors of metalloproteinases 1 (TIMP-1), and vascular endothelial growth factor (VEGF). Progesterone was decreased and alpha melanocyte stimulating hormone (α-MSH) was increased in F2 males, and brain-derived neurotrophic factor (BDNF) was decreased in F2 females. Changes in α1AGP, GM-CSF, progesterone, and α-MSH were correlated with decreased allogrooming in the F2 offspring of stressed dams. These results support the hypothesis that transgenerational social stress affects both the immune system and social behavior, and also support previous studies on the adverse effects of early life stress on immune functioning and stress associated immunological disorders, including the increasing prevalence of asthma. The immune system may represent an important transgenerational etiological factor in disorders which involve social and/or early life stress associated changes in social behavior, such as depression, anxiety, and autism, as well as comorbid immune disorders. Future studies involving immune and/or endocrine assessments and manipulations will address specific questions of function and causation, and may identify novel preventative measures and treatments for the growing number of immune mediated disorders.

Biomarkers of Endothelial Activation Are Associated with Poor Outcome in Critical Illness

Background

Endothelial activation plays a role in organ dysfunction in the systemic inflammatory response syndrome (SIRS). Angiopoietin-1 (Ang-1) promotes vascular quiescence while angiopoietin-2 (Ang-2) mediates microvascular leak. Circulating levels of Ang-1 and Ang-2 in patients with SIRS could provide insight on risks for organ dysfunction and death distinct from inflammatory proteins. In this study, we determined if biomarkers of endothelial activation and inflammation exhibit independent associations with poor outcomes in SIRS.

Methods

We studied 943 critically ill patients with SIRS admitted to an Intensive Care Unit (ICU) of an academic medical center. We measured plasma levels of endothelial markers (Ang-1, Ang-2, soluble vascular cell adhesion molecule-1 (sVCAM-1)) and inflammatory markers (interleukin-6 (IL-6), interleukin-8 (IL-8), granulocyte-colony stimulating factor (G-CSF), soluble tumor necrosis factor receptor-1 (sTNFR-1)) within 24 hours of enrollment. We tested for associations between each marker and 28 day mortality, shock, and day 3 sequential organ failure assessment (SOFA) score. For 28 day mortality, we performed sensitivity analysis for those subjects with sepsis and those with sterile inflammation. We used multivariate models to adjust for clinical covariates and determine if associations identified with endothelial activation markers were independent of those observed with inflammatory markers.

Results

Higher levels of all biomarkers were associated with increased 28 day mortality except levels of Ang-1 which were associated with lower mortality. After adjustment for comorbidities and sTNFR-1 concentration, a doubling of Ang-1 concentration was associated with lower 28 day mortality (Odds ratio (OR) = 0.81; p<0.01), shock (OR = 0.82; p<0.001), and SOFA score (β = -0.50; p<0.001), while Ang-2 concentration was associated with increased mortality (OR = 1.55; p<0.001), shock (OR = 1.51; p<0.001), and SOFA score (β = +0.63; p<0.001). sVCAM-1 was not independently associated with SIRS outcomes.

Conclusions

In critically ill patients with SIRS, early measurements of Ang-1 and Ang-2 are associated with death and organ dysfunction independently of simultaneously-measured markers of inflammation.

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.

Laboratory Diagnosis of Sepsis? No SIRS, Not Just Yet

In order to maximize the benefit of prompt antimicrobial therapy and avoid the risk associated with inappropriate use of antimicrobial agents, patients with suspected sepsis must be rapidly differentiated from patients with systemic inflammatory response syndrome (SIRS). In combination with standard microbiological testing, a number of biomarkers have been recently evaluated for this purpose, and the performance characteristics of the most promising of these are reviewed.

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.

Inflammation, vasospasm, and brain injury after subarachnoid hemorrhage

Subarachnoid hemorrhage (SAH) can lead to devastating neurological outcomes, and there are few pharmacologic treatments available for treating this condition. Both animal and human studies provide evidence of inflammation being a driving force behind the pathology of SAH, leading to both direct brain injury and vasospasm, which in turn leads to ischemic brain injury. Several inflammatory mediators that are elevated after SAH have been studied in detail. While there is promising data indicating that blocking these factors might benefit patients after SAH, there has been little success in clinical trials. One of the key factors that complicates clinical trials of SAH is the variability of the initial injury and subsequent inflammatory response. It is likely that both genetic and environmental factors contribute to the variability of patients' post-SAH inflammatory response and that this confounds trials of anti-inflammatory therapies. Additionally, systemic inflammation from other conditions that affect patients with SAH could contribute to brain injury and vasospasm after SAH. Continuing work on biomarkers of inflammation after SAH may lead to development of patient-specific anti-inflammatory therapies to improve outcome after SAH.

Consideration of the cellular microenvironment: physiologically relevant co-culture systems in drug discovery

There is renewed interest in phenotypic approaches to drug discovery, using cell-based assays to select new drugs, with the goal of improving pharmaceutical success. Assays that are more predictive of human biology can help researchers achieve this goal. Primary cells are more physiologically relevant to human biology and advances are being made in methods to expand the available cell types and improve the potential clinical translation of these assays through the use of co-cultures or three-dimensional (3D) technologies. Of particular interest are assays that may be suitable for industrial scale drug discovery. Here we review the use of primary human cells and co-cultures in drug discovery and describe the characteristics of co-culture models for inflammation biology (BioMAP systems), neo-vascularization and tumor microenvironments. Finally we briefly describe technical trends that may enable and impact the development of physiologically relevant co-culture assays in the near future.

Soluble adhesion molecules as markers for sepsis and the potential pathophysiological discrepancy in neonates, children and adults

Sepsis is a severe and life-threatening systemic inflammatory response to infection that affects all populations and age groups. The pathophysiology of sepsis is associated with aberrant interaction between leukocytes and the vascular endothelium. As inflammation progresses, the adhesion molecules that mediate these interactions become shed from cell surfaces and accumulate in the blood as soluble isoforms that are being explored as potential prognostic disease biomarkers. We critically review the studies that have tested the predictive value of soluble adhesion molecules in sepsis pathophysiology with emphasis on age, as well as the underlying mechanisms and potential roles for inflammatory shedding. Five soluble adhesion molecules are associated with sepsis, specifically, E-selectin, L-selectin and P-selectin, intercellular adhesion molecule-1 and vascular cell adhesion molecule-1. While increased levels of these soluble adhesion molecules generally correlate well with the presence of sepsis, their degree of elevation is still poorly predictive of sepsis severity scores, outcome and mortality. Separate analyses of neonates, children and adults demonstrate significant age-dependent discrepancies in both basal and septic levels of circulating soluble adhesion molecules. Additionally, a range of both clinical and experimental studies suggests protective roles for adhesion molecule shedding that raise important questions about whether these should positively or negatively correlate with mortality. In conclusion, while predictive properties of soluble adhesion molecules have been researched intensively, their levels are still poorly predictive of sepsis outcome and mortality. We propose two novel directions for improving clinical utility of soluble adhesion molecules: the combined simultaneous analysis of levels of adhesion molecules and their sheddases; and taking age-related discrepancies into account. Further attention to these issues may provide better understanding of sepsis pathophysiology and increase the usefulness of soluble adhesion molecules as diagnostic and predictive biomarkers.

Real-time monitoring of cell mechanical changes induced by endothelial cell activation and their subsequent binding with leukemic cell lines

Endothelial cell (EC) activation and their subsequent binding with different cells have various mechanical consequences that, if monitored real time, can serve as a functional biomarker of many pathophysiological response mechanisms. This work presents an innovative and facile strategy to conduct such monitoring using quartz crystal microbalance (QCM), thereby relating the shifts in its frequency and motional resistance to morphological changes upon cell-cell and cell-substrate interactions. By activating ECs with TNF-α and then characterizing their binding with HL-60 and KG-1 leukemia cells, we are able to induce the mechanical changes in ECs especially in the region of cell-substrate contact which resulted in dynamically coupled mass and viscoelastic changes representing the extent of both activation and binding. The activated ECs suffered a decrease of cellular contact area, leading to positive frequency shift and decreased motional resistance. The binding of leukemia cells onto pre-activated ECs exerted a mechanical force to regain the cell surface contact which resulted in the obvious QCM responses opposite to that of activation, and proportional to the number of cells added, in spite of the fact that these added cells are extremely outside the extinction boundary of the shear wave generated by QCM. Different cell lines demonstrate different attachment behavior, which was detected by the QCM. Despite these variations are quite subtle, yet the sensitivity of the technique for dynamic changes at the interface makes them detectable. Moreover, the reproducibility of the generated data determined at each step by deviation measurements (<10%) in response plot was very high despite the high possible heterogeneity in cell populations. The results are explained on the basis of simple theoretical and physical models, although, the development of a more quantitative and precise model is underway in our laboratory.

Biomarkers in sepsis

There is much enthusiasm and interest in sepsis biomarkers, particularly because sepsis is a highly lethal condition, its diagnosis is challenging, and even simple treatment with antibiotics has led to serious adverse consequences such as emergence of resistant pathogens. Yet development of a sepsis biomarker requires many more steps than simply finding an association between a particular molecule and a clinical state or outcome. Demonstration of improvement of therapeutic practice using receiver-operating characteristic and other analyses is important. Validation in independent, prospective and, preferably, multicenter trials is essential. Many promising candidate sepsis biomarkers have recently been proposed. While procalcitonin (PCT) is currently the most studied sepsis biomarker, evidence of potential value has been found for a wide array of blood biomarkers including proteins, mRNA expression in whole blood or leukocytes, micro-RNAs (miRNA), pathogen and host DNA, pathogen and host genetic variants and metabolomic panels, and even in the novel use of currently available clinical data. While the most common early reports link putative sepsis biomarker levels to severity of illness and outcome (prognostic), this is not anticipated to be their primary use. More important is the distinction between infection and noninfectious inflammatory responses (diagnostic) and the use of sepsis biomarkers to direct therapy (predictive).

Interleukin-6 at discharge predicts all-cause mortality in patients with sepsis

PURPOSE

Interleukin-6 (IL-6) is a proinflammatory cytokine that plays a central role in the pathogenesis of sepsis. We aim to investigate the association between IL-6 and all-cause mortality in patients with sepsis.

METHODS

A cohort of 40 elderly patients with sepsis was identified between March 2009 and June 2010 at Rambam Health Medical Campus, Haifa, Israel. The cohort was followed up for all-cause mortality occurring during the 6 months after hospital discharge. Cox proportional hazard model was used to assess the association between IL-6 and all-cause mortality.

RESULTS

Iinterleukin-6 at discharge had a higher predictive accuracy for all-cause mortality when compared with IL-6 at admission. The area under the curve was 0.752 (P = .015) and 0.545 (P = .661), respectively. Eleven (27.5%) patients died during follow-up; the subjects who died have higher IL-6 levels at discharge (median, 50.6 pg/mL [interquartile range, 39.6-105.9]) compared with survivors at the end of follow-up (median, 35.4 [interquartile range, 15.8-49]; P = .014). The risk of all-cause mortality was higher in subjects with IL-6 levels above the median compared with subjects with lower IL-6 levels (log-rank P = .017). On multivariate Cox proportional analysis, adjusting for the potential confounders, IL-6 at discharge remained an independent predictor for 6 month all-cause mortality (hazard ratio, 6.05 [1.24-24.20]) for levels above the median compared with lower levels.

CONCLUSIONS

Iinterleukin-6 at discharge is an independent predictor of all-cause mortality in patients with sepsis. Compared with IL-6 at admission, IL-6 at discharge better predicts all-cause mortality.

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.