Analytic review: Interleukin-6 in surgery, trauma, and critical care: part I: basic science

Circulating MicroRNAs as Biomarkers for Sepsis

Sepsis represents a major cause of lethality during intensive care unit (ICU) treatment. Pharmacological treatment strategies for sepsis are still limited and mainly based on the early initiation of antibiotic and supportive treatment. In this context, numerous clinical and serum based markers have been evaluated for the diagnosis, the severity, and the etiology of sepsis. However until now, few of these factors could be translated into clinical use. MicroRNAs (miRNAs) do not encode for proteins but regulate gene expression by inhibiting the translation or transcription of their target mRNAs. Recently it was demonstrated that miRNAs are released into the circulation and that the spectrum of circulating miRNAs might be altered during various pathologic conditions, such as inflammation, infection, and sepsis. By using array- and single PCR-based methods, a variety of deregulated miRNAs, including miR-25, miR-133a, miR-146, miR-150, and miR-223, were described in the context of sepsis. Some of the miRNAs correlated with the disease stage, as well as patients' short and long term prognosis. Here, we summarize the current findings on the role of circulating miRNAs in the diagnosis and staging of sepsis in critically ill patients. We compare data from patients with findings from animal models and, finally, highlight the challenges and drawbacks that currently prevent the use of circulating miRNAs as biomarkers in clinical routine.

Active Negative Pressure Peritoneal Therapy After Abbreviated Laparotomy: The Intraperitoneal Vacuum Randomized Controlled Trial

Supplemental Digital Content is Available in the Text.

This randomized trial observed a survival difference between patients randomized to the ABThera versus Barker's vacuum pack after abbreviated laparotomy. As this difference did not seem to be mediated by improved peritoneal fluid drainage, fascial closure rates, or markers of systemic inflammation, it should be confirmed by a multicenter trial.

Objective:

To determine whether active negative pressure peritoneal therapy with the ABThera temporary abdominal closure device reduces systemic inflammation after abbreviated laparotomy.

Background:

Excessive systemic inflammation after abdominal injury or intra-abdominal sepsis is associated with poor outcomes.

Methods:

We conducted a single-center, randomized controlled trial. Forty-five adults with abdominal injury (46.7%) or intra-abdominal sepsis (52.3%) were randomly allocated to the ABThera (n = 23) or Barker's vacuum pack (n = 22). On study days 1, 2, 3, 7, and 28, blood and peritoneal fluid were collected. The primary endpoint was the difference in the plasma concentration of interleukin-6 (IL-6) 24 and 48 hours after temporary abdominal closure application.

Results:

There was a significantly lower peritoneal fluid drainage from the ABThera at 48 hours after randomization. Despite this, there was no difference in plasma concentration of IL-6 at baseline versus 24 (P = 0.52) or 48 hours (P = 0.82) between the groups. There was also no significant intergroup difference in the plasma concentrations of IL-1β, −8, −10, or −12 p70 or tumor necrosis factor α between these time points. The cumulative incidence of primary fascial closure at 90 days was similar between groups (hazard ratio, 1.6; 95% confidence interval, 0.82–3.0; P = 0.17). However, 90-day mortality was improved in the ABThera group (hazard ratio, 0.32; 95% confidence interval, 0.11–0.93; P = 0.04).

Conclusions:

This trial observed a survival difference between patients randomized to the ABThera versus Barker's vacuum pack that did not seem to be mediated by an improvement in peritoneal fluid drainage, fascial closure rates, or markers of systemic inflammation.

Trial Registration:

ClinicalTrials.gov identifier NCT01355094.

Early hyperlactatemia predicts pancreatic fistula after surgery

Background

Postoperative pancreatic fistula (POPF) is a major complication after pancreatic surgery and results from an impaired healing of the pancreatic enteric anastomosis. Whether perioperative hemodynamic fluid management aiming to provide an adequate tissue perfusion could influence the occurrence of POPF is unknown. Serum lactate level is a well-recognized marker of decreased tissue perfusion and is known to be associated with higher morbidity and mortality in various postoperative settings. We aimed to determine in a retrospective high-volume center’s cohort whether postoperative hyperlactatemia could predict POPF occurrence.

Method

We conducted a retrospective analysis of 96 consecutive patients admitted in the intensive care unit (ICU) after pancreaticoduodenectomy or distal pancreatectomy. Univariate analysis was conducted to compare lactate levels at 6 h between patients evolving with versus without POPF. A logistic regression model was developed and included potential confounding factors.

Results

POPF occurred in 28 patients (29 %). Serum lactate level 6 h after admission was significantly higher in the POPF group (2.8 mmol/L [95 % confidence interval (CI): 2.1–3.5] versus 1.8 mmol/L [95 % CI: 1.8–2.4], p-value = 0.04) whereas it did not differ at ICU admission or at 12 h. Despite similar cumulative fluid balance, fluid intake and vasopressor use, hyperlactatemia > 2.5 mmol/L (Odds ratio (OR): 3.58; 95 % CI: 1.22–10.48; p-value = 0.020) and red blood cells transfusion (OR: 1.24; 95 % CI: 1.03–1.49; p-value = 0.022) were found to be independent predictive factors of POPF occurrence.

Conclusion

In patients undergoing partial pancreatectomy, hyperlactatemia measured 6 h after ICU admission is a predictive factor for the occurrence of POPF. Inflammatory changes after surgery may account for this observation and should be further evaluated.

Influence of propofol, isoflurane and enflurance on levels of serum interleukin-8 and interleukin-10 in cancer patients

OBJECTIVE

To observe the influence of propofol, isoflurane and enflurance on interleukin-8 (IL-8) and IL-10 levels in cancer patients.

METHODS

Ninety cancer patients with selective operation from March 2011 to May 2014 were randomly divided into group A (34 cases), group B (28 cases) and group C (28 cases). Intramuscular injections of scopine hydrochloride and phenobarbital sodium were routinely conducted to 3 groups. After general anesthesia was induced, tracheal intubations were given. During the maintenance of anesthesia, 0.5~1.0 mg/ kg propofol was intravenously injected to group A discontinuously, while continuous suctions of isoflurane and enflurance were subsequently performed to group B and C correspondingly. Clinical outcomes, postoperative complications as well as serum IL-8 and IL-10 levels before operation (T0), at the time of skin incision (T1), 3 h after the beginning of the operation (T2) and 24 h (T3) and 72 h (T4) after the operation were observed among 3 groups.

RESULTS

Operations in all groups were successfully completed. The rates of surgery associated complications were 8.82% (3/34), 7.14% (2/28) and 7.14% (2/28) in group A, B and C, respectively, and there were no significant differences (P>0.05). Serum IL-8 and IL-10 levels increased gradually from the beginning of the operation and reached the peak at T3, and were evidently higher at each time point than at T0 (P<0.01). At T1, serum IL-8 and IL-10 levels had no significant differences among 3 groups (P<0.05), but the differences were significant at T2, T3 and T4 (P<0.05). Moreover, correlation analysis suggested that serum IL-8 level was in positive relation with IL-10 level (r=0.952, P<0.01).

CONCLUSIONS

Propofol, which is better in inhibiting serum IL-8 secretion and improving IL-10 secretion than isoflurane and enflurance, can be regarded as a preferable anesthetic agent in inhibiting traumatic inflammatory responses.

Assessment of tissue damage due to percutaneous nephrolithotomy using serum concentrations of inflammatory mediators

OBJECTIVES

To determine the percutaneous nephrolithotomy (PCNL) effects on the tissues using the quantification of inflammatory mediators, and to assess their impact on the development of postoperative complications.

PATIENTS AND METHODS

Prospective observational non-randomized study on 40 patients underwent to PCNL. 50 patients with kidney stone who were treated by extracorporeal shock wave lithotripsy (ESWL) were used as control group. Interleukin-1beta (IL-1β), tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6) and C-reactive protein (CRP) were determined at baseline (T0: before treatment), and at 2, 6 and 24hours after (T1, T2 and T3).

RESULTS

No relevant changes on IL-1β and TNF-α were found. IL-6 showed two peaks at 2 and 6hours post-PCNL (median 17.8 and 15.8 pg/mL, respectively). At 24hours CRP had reached its peak value (3.4mg/L). The group treated with ESWL no showed significant changes in any of the markers. The serum concentration of IL-6 and CRP at 24hours post-NLP is different depending on the occurrence of complications (P=.001 and P=.039, respectively). IL-6 showed a good predictive power for the development of complications (AUC .801).

CONCLUSIONS

Tissue damage caused by the PCNL is low. This damage increases significantly in those cases showing postoperative complications. IL-6 at 24hours has been shown to be a good predictive tool for the development of complications.

Cloning and characterization of the proximal promoter region of rainbow trout (Oncorhynchus mykiss) interleukin-6 gene

Interleukin-6 (IL6) is a pleiotropic cytokine with important immunoregulatory functions. Its expression is inducible in immune cells and tissues of several fish species. We also found that IL6 mRNA abundance was significantly increased in spleen, liver, and gill of rainbow trout after experimental infection with Aeromonas salmonicida. Genomic DNA sequences of IL6 orthologs from three salmonid species revealed a conserved exon/intron structure and a high overall nucleotide identity of >88%. To uncover key mechanisms regulating IL6 expression in salmonid fish, we amplified a fragment of the proximal IL6 promoter from rainbow trout and identified in-silico conserved binding sites for NF-κB and CEBP. The activity of this IL6 promoter fragment was analyzed in the established human embryonic kidney line HEK-293. Luciferase- and GFP-based reporter systems revealed that the proximal IL6 promoter is activated by Escherichia coli. Essentially, both reporter systems proved that NF-κB p50, but not NF-κB p65 or CEBP, activates the IL6 promoter fragment. Truncation of this fragment caused a significant decrease in IL6 promoter activation. This characterization of the proximal promoter of the IL6-encoding gene provides basic knowledge about the IL6 gene expression in rainbow trout.

Role of N-terminal pro-B-type natriuretic peptide, high-sensitivity C-reactive protein, and inteleukin-6 in predicting a poor outcome after a stroke

OBJECTIVE

N-terminal pro-B-type natriuretic peptide (NT-proBNP), high-sensitivity C-reactive protein (hsCRP), and interleukin-6 (IL-6) concentrations can be important biomarkers in the acute stroke setting. In acute ischemic and hemorrhagic stroke patients, we investigated the association of NT-proBNP, hsCRP, and IL-6 serum concentrations with stroke severity and functional and cognitive outcomes at discharge.

METHODS

Seventy-eight patients (53 men; median age 72 years) admitted with ischemic or hemorrhagic stroke within 48 h of symptom onset were evaluated for clinical stroke severity (Scandinavian stroke scale; SSS), functional status before the stroke (modified Rankin scale; mRS), and cerebrovascular disease risk factors. Cognitive (Mini Mental State Examination) and functional (mRS) outcomes were evaluated at hospital discharge. Blood samples were drawn for the assessment of NT-proBNP, hsCRP, and IL-6 concentrations within 24 h of admission.

RESULTS

Greater NT-proBNP and hsCRP serum concentrations were associated with greater clinical stroke severity, adjusting for the patients' gender, age, stroke type, mRS score on admission, and presence of heart failure (β = -0.292, p = 0.012; β = -0.303, p = 0.009). In multivariate adjusted regression models with IL-6, hsCRP, and NT-proBNP considered together, IL-6 and hsCRP remained associated with worse functional (β = 0.210, p = 0.022) and cognitive (β = -0.269, p = 0.014) outcomes at discharge, respectively. In receiver operating characteristic analyses, the investigated blood biomarkers produced a minimal increase in predictive values for outcomes at discharge above the SSS score, age, and gender.

CONCLUSIONS

In acute stroke patients, greater NT-proBNP and hsCRP serum concentrations are independently associated with greater clinical stroke severity. Elevated concentrations of IL-6 and hsCRP are associated with worse functional and cognitive outcomes at discharge, respectively.

Removal of inflammatory ascites is associated with dynamic modification of local and systemic inflammation along with prevention of acute lung injury: in vivo and in silico studies

BACKGROUND

Sepsis-induced inflammation in the gut/peritoneal compartment occurs early in sepsis and can lead to acute lung injury (ALI). We have suggested that inflammatory ascites drives the pathogenesis of ALI and that removal of ascites with an abdominal wound vacuum prevents ALI. We hypothesized that the time- and compartment-dependent changes in inflammation that determine this process can be discerned using principal component analysis (PCA) and Dynamic Bayesian Network (DBN) inference.

METHODS

To test this hypothesis, data from a previous study were analyzed using PCA and DBN. In that study, two groups of anesthetized, ventilated pigs were subjected to experimental sepsis via intestinal ischemia/reperfusion and placement of a peritoneal fecal clot. The control group (n = 6) had the abdomen opened at 12 h after injury (T12) with attachment of a passive drain. The peritoneal suction treatment (PST) group (n = 6) was treated in an identical fashion except that a vacuum was applied to the peritoneal cavity at T12 to remove ascites and maintained until T48. Multiple inflammatory mediators were measured in ascites and plasma and related to lung function (PaO2/FIO2 ratio and oxygen index) using PCA and DBN.

RESULTS

Peritoneal suction treatment prevented ALI based on lung histopathology, whereas control animals developed ALI. Principal component analysis revealed that local to the insult (i.e., ascites), primary proinflammatory cytokines play a decreased role in the overall response in the treatment group as compared with control. In both groups, multiple, nested positive feedback loops were inferred from DBN, which included interrelated roles for bacterial endotoxin, interleukin 6, transforming growth factor β1, C-reactive protein, PaO2/FIO2 ratio, and oxygen index. von Willebrand factor was an output in control, but not PST, ascites.

CONCLUSIONS

These combined in vivo and in silico studies suggest that in this clinically realistic paradigm of sepsis, endotoxin drives the inflammatory response in the ascites, interplaying with lung dysfunction in a feed-forward loop that exacerbates inflammation and leads to endothelial dysfunction, systemic spillover, and ALI; PST partially modifies this process.

Post-traumatic immunosuppression is reversed by anti-coagulated salvaged blood transfusion: deductions from studying immune status after knee arthroplasty

Major trauma increases vulnerability to systemic infections due to poorly defined immunosuppressive mechanisms. It confers no evolutionary advantage. Our objective was to develop better biomarkers of post-traumatic immunosuppression (PTI) and to extend our observation that PTI was reversed by anti-coagulated salvaged blood transfusion, in the knowledge that others have shown that non-anti-coagulated (fibrinolysed) salvaged blood was immunosuppressive. A prospective non-randomized cohort study of patients undergoing primary total knee arthroplasty included 25 who received salvaged blood transfusions collected post-operatively into acid-citrate-dextrose anti-coagulant (ASBT cohort), and 18 non-transfused patients (NSBT cohort). Biomarkers of sterile trauma included haematological values, damage-associated molecular patterns (DAMPs), cytokines and chemokines. Salvaged blood was analysed within 1 and 6 h after commencing collection. Biomarkers were expressed as fold-changes over preoperative values. Certain biomarkers of sterile trauma were common to all 43 patients, including supranormal levels of: interleukin (IL)-6, IL-1-receptor-antagonist, IL-8, heat shock protein-70 and calgranulin-S100-A8/9. Other proinflammatory biomarkers which were subnormal in NSBT became supranormal in ASBT patients, including IL-1β, IL-2, IL-17A, interferon (IFN)-γ, tumour necrosis factor (TNF)-α and annexin-A2. Furthermore, ASBT exhibited subnormal levels of anti-inflammatory biomarkers: IL-4, IL-5, IL-10 and IL-13. Salvaged blood analyses revealed sustained high levels of IL-9, IL-10 and certain DAMPs, including calgranulin-S100-A8/9, alpha-defensin and heat shock proteins 27, 60 and 70. Active synthesis during salvaged blood collection yielded increasingly elevated levels of annexin-A2, IL-1β, Il-1-receptor-antagonist, IL-2, IL-4, IL-6, IL-8, IL-10, IL-12p70, IL-17A, IFN-γ, TNF-α, transforming growth factor (TGF)-β1, monocyte chemotactic protein-1 and macrophage inflammatory protein-1α. Elevated levels of high-mobility group-box protein-1 decreased. In conclusion, we demonstrated that anti-coagulated salvaged blood reversed PTI, and was attributed to immune stimulants generated during salvaged blood collection.

Pleiotropic effects of interleukin-6 in a "two-hit" murine model of acute respiratory distress syndrome

Patients with acute respiratory distress syndrome (ARDS) exhibit elevated levels of interleukin-6 (IL-6), which correlate with increased morbidity and mortality. The exact role of IL-6 in ARDS has proven difficult to study because it exhibits either pro- or anti-inflammatory actions in mouse models of lung injury, depending on the model utilized. In order to improve understanding of the role of this complex cytokine in ARDS, we evaluated IL-6 using the clinically relevant combination of lipopolysaccharide (LPS) and ventilator-induced lung injury (VILI) in IL-6(-/-) mice. Bronchoalveolar lavage fluid (BAL), whole-lung tissue, and histology were evaluated for inflammatory markers of injury. Transendothelial electrical resistance was used to evaluate the action of IL-6 on endothelial cells in vitro. In wild-type mice, the combination model showed a significant increase in lung injury compared to either LPS or VILI alone. IL-6(-/-) mice exhibited a statistically significant decrease in BAL cellular inflammation as well as lower histologic scores for lung injury, changes observed only in the combination model. A paradoxical increase in BAL total protein was observed in IL-6(-/-) mice exposed to LPS, suggesting that IL-6 provides protection from vascular leakage. However, in vitro data showed that IL-6, when combined with its soluble receptor, actually caused a significant increase in endothelial cell permeability, suggesting that the protection seen in vivo was likely due to complex interactions of IL-6 and other inflammatory mediators rather than to direct effects of IL-6. These studies suggest that a dual-injury model exhibits utility in evaluating the pleiotropic effects of IL-6 in ARDS on inflammatory cells and lung endothelium.

Is Minimally Invasive Spine Surgery Also Minimally Pro-Inflammatory? Muscular Markers, Inflammatory Parameters and Cytokines to Quantify the Operative Invasiveness Assessment in Spine Fusion

Over the last decades, minimally invasive surgery (MIS) techniques entered in the surgical routine due to their major advantage in reducing the unnecessary exposure of tissue and, thus, the trauma. Even in the context of orthopedics and spine surgery these practices have been widely developed and applied. Besides the clinical outcome of the patients, few studies have quantitatively assessed the traumatic and inflammatory effects of a specific surgical technique. Indeed, currently, a universally accepted biological outcome measure, such as a panel of biochemical markers, to define the success of MIS approach is still lacking. We reviewed the literature to collect the published data regarding the quantitative analysis of trauma induced by either conventional or minimally invasive surgery with the aim of highlighting evidence useful to guide future studies. Previous publications show some evidence in support of the hypothesis that MIS approaches are less traumatic, and possibly less pro-inflammatory, than conventional ones. Creatin kinase (as a marker of muscular damage) and C-reactive protein (as a marker of systemic inflammation) seem to reproducibly follow different trends in minimally invasive surgery compared to conventional procedures. Moreover, cytokines, such as interleukin (IL)-6 and IL-10 are also promising markers in this context.

Serum level of IL-10 is increased in patients with endometriosis, and IL-10 promotes the growth of lesions in a murine model

Immune dysregulation may be involved in the development of endometriosis. The anti-inflammatory cytokine IL-10 plays an important role in eliminating unwanted cells and cellular debris in a silent way. We investigated the modulatory role of IL-10 in the development of endometriosis. We observed that the serum level of IL-10 in patients with endometriosis was significantly higher than that in healthy subjects or in control subjects with other gynecological disease. Monocyte-derived dendritic cells acquired from male donors and subsequently conditioned with serum from women with endometriosis exhibited a tolerogenic phenotype, including increased IL-10 production, lower IL-12 secretion, and down-regulation of CD86 and HLA-DR molecules. Depletion of IL-10 activity in a C57BL/6 mouse model of surgically induced endometriosis significantly decreased the size of endometrial lesions. In contrast, IL-10 administration promoted the growth of endometrial lesions in this model. In addition, infiltrated plasmacytoid dendritic cells were the primary IL-10-secreting immune cells in endometrial lesions. Our findings suggest that IL-10 may suppress immunity against endometrial implants, contributing to development of endometriosis.

Role of biomarkers in sepsis care

Sepsis is one of the leading causes of mortality and morbidity, even with the current availability of extended-spectrum antibiotics and advanced medical care. Biomarkers offer a tool in facilitating early diagnosis, in identifying patient populations at high risk of complications, and in monitoring progression of the disease, which are critical assessments for appropriate therapy and improvement in patient outcomes. Several biomarkers are already available for clinical use in sepsis; however, their effectiveness in many instances is limited by the lack of specificity and sensitivity to characterize the presence of an infection and the complexity of the inflammatory and immune processes and to stratify patients into homogenous groups for specific treatments. Current advances in molecular techniques have provided new tools facilitating the discovery of novel biomarkers, which can vary from metabolites and chemical products present in body fluids to genes and proteins in circulating blood cells. The purpose of this review was to examine the current status of sepsis biomarkers, with special emphasis on emerging markers, which are undergoing validation and may transition into clinical practice for their informative value in diagnosis, prognosis, or response to therapy. We will also discuss the new concept of combination biomarkers and biomarker risk models, their existing challenges, and their potential use in the daily management of patients with sepsis.

Hemorrhagic shock and resuscitation are associated with peripheral blood mononuclear cell mitochondrial dysfunction and immunosuppression

BACKGROUND

Trauma and hypovolemic shock are associated with mitochondrial dysfunction and septic complications. We hypothesize that hypovolemic shock and resuscitation results in peripheral blood mononuclear cell (PBMC) mitochondrial dysfunction that is linked to immunosuppression.

METHODS

With the use of a decompensated shock model, Long-Evans rats were bled to a mean arterial pressure of 40 mm Hg until the blood pressure could no longer be maintained without fluid infusion. Shock was sustained by incremental infusion of lactated Ringer's solution until 40% of the shed volume had been returned (severe shock). Animals were resuscitated with four times the shed volume in lactated Ringer's solution over 60 minutes (resuscitation). Control animals underwent line placement but were not hemorrhaged. Animals were randomized to control (n = 5), severe shock (n = 5), or resuscitation (n = 6) groups. At each time point, PBMC were isolated for mitochondrial function analysis using flow cytometry and high-resolution respirometry. Immune function was evaluated by quantifying serum interleukin 6 (IL-6) and tumor necrosis factor (TNF-α) after PBMC stimulation with lipopolysaccharide. The impact of plasma on mitochondrial function was evaluated by incubating PBMCs harvested following severe shock with control plasma. PBMCs from control animals were likewise mixed with plasma collected following resuscitation. Student's t test and Pearson correlations were performed (significance, p < 0.05).

RESULTS

Following resuscitation, PBMCs demonstrated significant bioenergetic failure with a marked decrease in basal, maximal, and adenosine triphosphate-linked respiration. Mitochondrial membrane potential also decreased significantly by 50% following resuscitation. Serum IL-6 increased, while lipopolysaccharide stimulated TNF-α production decreased dramatically following shock and resuscitation. Observed mitochondrial dysfunction correlated significantly with IL-6 and TNF-α levels. PBMCs demonstrated significant mitochondrial recovery when incubated in control serum, whereas control PBMCs developed depressed function when incubated with serum collected following severe shock.

CONCLUSION

Mitochondrial dysfunction following hemorrhagic shock and resuscitation was associated with the inhibition of PBMC response to endotoxin that may lead to an immunosuppressed state.

The stress response to surgery and postoperative delirium: evidence of hypothalamic-pituitary-adrenal axis hyperresponsiveness and decreased suppression of the GH/IGF-1 Axis

INTRODUCTION

The aim of this study is to determine whether postoperative delirium is associated with dysregulation of hypothalamic-pituitary-adrenal and growth hormone/insulin-like growth factor 1 (GH/IGF-1) responses following acute systemic inflammation.

METHODS

Plasma levels of cortisol, IGF-1, C-reactive protein, interleukin (IL)-6, IL-8, and IL-10 were measured before and after surgery in 101 patients ≥ 60 years without dementia undergoing elective hip arthroplasty. Participants were assessed with confusion assessment method and Diagnostic and Statistical Manual of Mental Disorders (Fourth Edition, Text Revision; DSM-IV-TR) postoperatively and 37 patients fulfilled the DSM-IV-TR criteria for delirium.

RESULTS

Preoperative plasma cortisol levels were similar in delirium and nondelirium groups (405.37 ± 189.04 vs 461.83 ± 219.39; P = .22). Participants with delirium had higher postoperative cortisol levels (821.67 ± 367.17 vs 599.58 ± 214.94; P = .002) with enhanced postoperative elevation in relation to baseline (1.9- vs 1.5-fold; P = .004). The plasma levels of IGF1 did not differ in delirium and nondelirium groups before (18.12 ± 7.58 vs 16.8 ± 7.86; P = .477) and following surgery (13.39 ± 5.94 vs 11.12 ± 6.2; P = .639), but the levels increased in relation to baseline more frequently in patients who developed delirium (24.3% vs 7.8%; P = .034). The magnitude of postoperative cortisol elevation correlated with ΔIL-6 (P = .485; P = .002), ΔIL-8 (P = .429; P = .008), and ΔIL-10 (P = .544; P < .001) only in patients with delirium.

CONCLUSIONS

Hypothalamic-pituitary-adrenal axis hyperresponsiveness and a less frequent suppression of the GH/IGF-1 axis in response to acute stress are possibly involved in delirium pathophysiology.

Peri-implant versus periodontal wound healing

AIM

Peri-implant gingival healing following one-stage implant placement was investigated and compared to periodontal healing.

METHODS

Healing at surgical sites [implant (I) and adjacent teeth (T+)] was compared to non-operated tooth (T-) in non-smokers receiving one-stage implant. Periodontal Indices (PI, GI) were recorded at surgery and up to 12 weeks post-operatively. Peri-implant (PICF) and gingival crevicular fluids (GCF) were analysed for cytokines, collagenases and inhibitors. Data were analysed by linear mixed model regression analysis and repeated measures anova.

RESULTS

Forty patients (22 females; 21-74 years old) completed the study. Surgical site GI, increased at week 1, decreased significantly during early healing (weeks 1-3; p = 0.0003) and continually decreased during late healing (weeks 6-12) for I (p < 0.01). PICF volume decreased threefold by week 12 (p = 0.0003). IL-6, IL-8, MIP-1β and TIMP-1 levels significantly increased at surgical sites at week one, significantly decreasing thereafter (p < 0.016). Week one IL-6, IL-8 and MIP-1β levels were ~threefold higher and TIMP-1 levels 63% higher, at I compared to T+ (p = 0.001).

CONCLUSION

Peri-implant gingival healing, as determined by crevicular fluid molecular composition, differs from periodontal healing. The observed differences suggest that peri-implant tissues, compared to periodontal tissues, represent a higher pro-inflammatory state.

The miRNAs of herpes simplex virus (HSV)

Herpes simplex virus (HSV) is a group of common human pathogens with two serotypes HSV-1 and HSV-2. The prevalence of HSV is worldwide. It primarily infects humans through epithelial cells, when it introduces a latent infection into the nervous system. During viral latency, only a region known as the latency-associated transcript (LAT) is expressed. The discovery of HSV miRNAs helps to draw a larger picture of the infection and pathogenesis of the virus. This review summarizes miRNAs found in HSV-1 and HSV-2 so far. The functional studies of miRNAs in HSV to date indicate that they play a stage-specific role coordinated with viral proteins to maintain the virus life cycle.

Acceleration of Wound Healing by Multiple Growth Factors and Cytokines Secreted from Multipotential Stromal Cells/Mesenchymal Stem Cells

BACKGROUND

Although multipotential stromal cells/mesenchymal stem cell (MSCs) initially gained attention because of their ability to differentiate into multiple cell lineages, it is their capacity to produce and secrete growth factors and cytokines that makes them particularly valuable as potential cell therapeutics.

THE PROBLEM

Wound healing is an intricate process consisting of several integrated stages, including angiogenesis, collagen production, and cell migration and proliferation. Coordinating these processes to ensure rapid and thorough wound healing is necessary when developing therapeutics. This coordination, however, is disrupted in chronic nonhealing wounds, wherein the impaired blood supply and resulting ischemia compromise cellular functions and make it difficult to deliver the necessary signaling molecules.

BASIC/CLINICAL SCIENCE ADVANCES

MSCs secrete a combination of growth factors and cytokines, which have been shown to promote wound repair. This combination of growth factors and cytokines successfully induces angiogenesis, reduces inflammation, and promotes fibroblast migration and collagen production.

CLINICAL CARE RELEVANCE

The growth factors and cytokines secreted by MSCs can be administered to wounds by either transplanting cells or, as a safer alternative, using the conditioned medium of MSCs, which contains these secreted bioactive molecules. For their success in reducing wound closure time, MSCs offer a promising option for treating chronic wounds. Still, possible undesirable effects of MSC-based therapeutics, such as keloid formation, need to be carefully studied.

CONCLUSION

With its strong ability to secrete diverse growth factors and cytokines, MSC-based therapeutics, either with cell transplantation or the conditioned medium, offers a novel approach toward chronic nonhealing wounds.

The immunopathology of sepsis: pathogen recognition, systemic inflammation, the compensatory anti-inflammatory response, and regulatory T cells

Sepsis, the systemic inflammatory response to infection, represents the major cause of death in critically ill veterinary patients. Whereas important advances in our understanding of the pathophysiology of this syndrome have been made, much remains to be elucidated. There is general agreement on the key interaction between pathogen-associated molecular patterns and cells of the innate immune system, and the amplification of the host response generated by pro-inflammatory cytokines. More recently, the concept of immunoparalysis in sepsis has also been advanced, together with an increasing recognition of the interplay between regulatory T cells and the innate immune response. However, the heterogeneous nature of this syndrome and the difficulty of modeling it in vitro or in vivo has both frustrated the advancement of new therapies and emphasized the continuing importance of patient-based clinical research in this area of human and veterinary medicine.

HSV-1 miR-H6 inhibits HSV-1 replication and IL-6 expression in human corneal epithelial cells in vitro

HSV-1 infection in the cornea could lead to blindness. The infected cell polypeptide 4 (ICP4) of herpes simplex virus 1 (HSV-1) is a regulator of viral transcription that is required for productive infection. It has been previously demonstrated that miR-H6 encoded from HSV-1 genome targets ICP4 to help maintain latency. In this study, synthesized miR-H6 mimics were transfected into HSV-1-infected human cornea epithelial (HCE) cells. The inhibition of HSV-1 replication and viral ICP4 expression in miR-H6-transfected HCE was confirmed by plaque assay, immunofluorescence, and Western blot. Compared to nontransfection or mock, miR-H6 produced a low-titer HSV-1 and weak ICP4 expression. In addition, miR-H6 can decrease the interleukin 6 released into the medium, which was determined by ELISA. Taken together, the data suggests that miR-H6 targeting of ICP4 inhibits HSV-1 productive infection and decreases interleukin 6 production in HCE, and this may provide an approach to prevent HSV-1 lytic infection and inhibit corneal inflammation.

Early interleukin-6 and slope of monocyte human leukocyte antigen-DR: a powerful association to predict the development of sepsis after major trauma

OBJECTIVE

Major trauma is characterized by a pro-inflammatory response, followed by an immunosuppression. Recently, in trauma patients, the lack of recovery of monocyte Human Leukocyte Antigen DR (mHLA-DR, a biomarker of ICU-acquired immunosuppression) between days 1-2 and days 3-4 has been demonstrated to be independently associated with sepsis development. The main objective of this study was to determine whether early measurements of IL-6 (interleukin-6) and IL-10 plasma concentrations (as markers of initial severity) could improve, in association with mHLA-DR recovery, the prediction of sepsis occurrence in severe trauma patients.

DESIGN

Prospective observational study over 24 months in a Trauma ICU at university hospital.

PATIENTS

Trauma patients with an ISS over 25 and age over 18 were included.

MEASUREMENTS AND MAIN RESULTS

mHLA-DR was assessed by flow cytometry, IL-6 and IL-10 concentrations by ELISA. 100 consecutive severely injured patients were monitored (mean ISS 37±10). 37 patients developed sepsis. IL-6 concentrations and slope of mHLA-DR expression between days 1-2 and days 3-4 were significantly different between septic and non-septic patients. IL-10 was not detectable in most patients. After adjustment for usual clinical confounders, when assessed as a pair, multivariate logistic regression analysis revealed that a slope of mHLA-DR expression (days 3-4/days 1-2)≤1.1 and a IL-6 concentration ≥ 67.1 pg/ml remained highly associated with the development of sepsis (adjusted OR 18.4, 95% CI 4.9; 69.4, p = .00002).

CONCLUSIONS

After multivariate regression logistic analysis, when assessed as a pair, a high IL-6 concentration and a persistent mHLA-DR decreased expression were found to be in relation with the development of sepsis with the best predictive value. This study underlines the usefulness of daily monitoring of immune function to identify trauma patients at a high risk of infection.

Dangkwisoo-san, an herbal medicinal formula, ameliorates acute lung inflammation via activation of Nrf2 and suppression of NF-κB

ETHNOPHARMACOLOGICAL RELEVANCE

Dangkwisoo-san (DS), an herbal medicinal formula, has long been used in Korea for the treatment of inflammatory complications caused by physical trauma. Although the therapeutic effect of DS is likely associated with anti-inflammatory activity, the precise underlying mechanisms are largely unknown. Here we sought to elucidate the possible mechanisms of anti-inflammatory activity of DS.

MATERIALS AND METHODS

The water extract of DS was orally fed to C57BL/6 mice for 14 days prior to LPS intranasal instillation for lung inflammation. The effects of DS on lung inflammation were determined by differential cell counting, lung histology, and semi-quantitative RT-PCR of lung sections. The effects of DS on the activities of Nrf2 and NF-κB were assessed by western blotting, semi-quantitative RT-PCR, and luciferase reporter assays in RAW 264.7, an NF-κB reporter cell line, and HEK 293 transfected with an NF-κB reporter construct.

RESULTS

Mice that were treated with a water extract of DS showed significant attenuation of lung inflammation induced by intranasal lipopolysaccharide (LPS) compared to control mice treated with vehicle. In vitro experiments show that DS activated Nrf2, an anti-oxidant transcription factor that protects from various inflammatory diseases, and induced Nrf2-regulated genes including GCLC, NQO-1 and HO-1. In addition, DS suppressed NF-κB activity and reduced the production of pro-inflammatory cytokines. Transfection experiment indicates that inhibition of NF-κB likely occurred upstream of IKK complex. Furthermore, DS enhanced the expression of HO-1 and suppressed that of IL-1β and TNF-α in inflamed mouse lungs.

CONCLUSIONS

These results suggest that the therapeutic effects of DS are related with suppression of inflammation, which is, at least in part, mediated by activation of anti-inflammatory factor Nrf2 and inhibition of pro-inflammatory factor NF-κB.

Platelet proteome in healthy volunteers who smoke

Smoking accelerates atherosclerosis and is a well-known risk factor for acute cardiovascular complications; however, the mechanisms of these effects have not been completely clarified. Recently developed proteomic approaches may offer new clues when combined with well-established functional tests. Platelet proteome of healthy smokers and non-smokers was resolved by two-dimensional difference gel electrophoresis, compared by Decyder software and identified by mass spectrometry analysis (nano-LC-MS/MS). In smokers, three proteins (Factor XIII-A subunit, platelet glycoprotein IIb and beta-actin) were significantly up-regulated, whereas WDR1 protein and chaperonine HSP60 were down-regulated. Furthermore, the highest scored network derived by Ingenuity Pathway Analysis using the modulated proteins as input showed the involvement of several proteins to be related to inflammation and apoptosis. Platelet function tests and the levels of markers of platelet and leukocyte activation were not different in smokers vs. non-smoker subjects. The platelet proteomic approach confirms that cigarette smoking triggers several inflammatory reactions and may help clarify some of the molecular mechanisms of smoke effect on cellular systems relevant for vascular integrity and human health.

Metabolic considerations in management of surgical patients

Metabolic changes after surgery, trauma, or serious illness have a complex pathophysiology. The early posttraumatic stress response is physiologic and associated with a state of hyperinflammation, increased oxygen consumption, and increased energy expenditure. These are part of a systemic reaction that encompasses a wide range of endocrinological, immunologic, and hematological effects. Surgery initiates changes in metabolism that can affect virtually all organs and tissues; the metabolic response results in hormone-mediated mobilization of endogenous substrates that leads to stress catabolism. Hypercatabolism has been associated with severe complications related to hyperglycemia, hypoproteinemia, and immunosuppression. Proper metabolic support is essential to restore homeostasis and ensure survival.