Airway Epithelial Hepcidin Coordinates Lung Macrophages and Immunity Against Bacterial Pneumonia Background: Hepcidin is a liver-derived master regulator of iron metabolism through its molecular target ferroportin, the only known mammalian iron exporter. Accumulated evidence has shown the important roles of hepatic hepcidin in host defense and infections. Hepcidin is also expressed by airway epithelial cells. However, the function of epithelial hepcidin during bacterial pneumonia remains unknown. Methods: Pneumonia was induced in hepcidin-1-deficient and wild-type mice using the most common bacterial agents, and the effects of hepcidin on survival, bacterial burden, iron status, and macrophage phagocytosis after bacterial pneumonia were assessed. Results: Hepcidin levels decreased in airway epithelium during common pneumonia, while lung macrophage-derived ferroportin levels and pulmonary iron concentrations increased. Lack of hepcidin in the airway epithelium worsened the outcomes of pneumonia. Manipulation of hepcidin level in the airway epithelium in mice with macrophage-specific ferroportin deletion did not affect the progress of pneumonia. Increased pulmonary iron concentration not only facilitated bacterial growth but also led to the defective phagocytic function of lung macrophages via activation of RhoA GTPase through oxidation of RhoGDI. Furthermore, enhancing the hepcidin level in the airway epithelium rescued mice from lethal bacterial pneumonia. Conclusions: These findings identify an uncharacterized important role of airway epithelial hepcidin in protection against bacterial pneumonia and provide the basis for novel alternative therapeutic strategies for combatting bacterial pneumonia in future translational research. Address reprint requests to QiXing Chen, PhD, Clinical Research Center, Children's Hospital, School of Medicine, Zhejiang University, BinSheng Road 3333, 310052 Hangzhou, China. E-mail: qixingchen@zju.edu.cn; Co-correspondence: XiangMing Fang, MD, Department of Anesthesiology, The First Affiliated Hospital, School of Medicine, Zhejiang University, QingChun Road 79, 310003 Hangzhou, China. E-mail: xmfang@zju.edu.cn. Received 23 August, 2019 Revised 13 September, 2019 Accepted 23 October, 2019 This work was supported by programs from the National Natural Science Foundation of China (grant numbers 81871543, 81571872, and 81701947) and Zhejiang Provincial Natural Science Foundation of China (grant number LY18H150001). The authors report no conflicts of interest. Supplemental digital content is available for this article. Direct URL citation appears in the printed text and is provided in the HTML and PDF versions of this article on the journal's Web site (www.shockjournal.com). This is an open-access article distributed under the terms of the Creative Commons Attribution-Non Commercial-No Derivatives License 4.0 (CCBY-NC-ND), where it is permissible to download and share the work provided it is properly cited. The work cannot be changed in any way or used commercially without permission from the journal. http://creativecommons.org/licenses/by-nc-nd/4.0 © 2019 by the Shock Society

Variability of Microcirculatory Measurements in Critically ill Patients Introduction: monitoring the microcirculation may be helpful in guiding resuscitation in patients with circulatory shock. Sublingual side-stream dark field imaging camera's allow for non-invasive, bedside evaluation of the microcirculation, although their use in clinical practice has not yet been validated. The GlycoCheck system automatically analyzes these images to determine glycocalyx thickness, red blood cell filling percentage and vessel density. Although GlycoCheck has been used to study microcirculation in critically ill patients, little is known about the reproducibility of measurements in this population. Materials and Methods: a total of 60 critically ill patients were studied. Three consecutive microcirculation measurements were performed with the GlycoCheck system in fourty of these patients by one of two experienced observers. Twenty patients were assessed by both observers. Intra- and interobserver variability were assessed using intra-class correlation coefficients (ICC's). Results: ICC's of single measurements were poor for glycocalyx thickness and good for filling percentage and vessel density. Reproducibility could be substantially increased for all parameters when three consecutive measurements were performed and averaged. Discussion: GlycoCheck can be used to study microcirculation. However, to obtain reliable results three consecutive measurements should be performed and averaged. The variation of the measurements currently hampers the clinical application in individual patients. Address reprint requests to Martine E. Bol, MSc, P. Debyelaan 25, 6229 HX Maastricht, PO Box 5800. E-mail: martine.bol@mumc.nl Received 14 August, 2019 Revised 5 September, 2019 Accepted 19 October, 2019 D. Beurskens received funding from an unrestricted grant (2014/01) from the Coenraad Hemker Foundation. Conflicts of Interest and Source of Funding: There are no conflicts of interest. © 2019 by the Shock Society

Should Albumin Be Considered For Prehospital Resuscitation in Austere Environments? A Prospective Randomized Survival Study in Rabbits Background: The new guidelines for prehospital care of combat casualties in shock recommend administration of whole blood or blood components to increase blood pressure to a permissible hypotensive level (i.e., hypotensive resuscitation, HR). We investigated if 2hrs of HR using limited volumes of whole blood, plasma or albumin would lead to full recovery and long-term survival of rabbits subjected to severe hemorrhagic shock (HS). Methods: Following instrumentation, laparotomy was performed on IV-anesthetized spontaneously breathing NZW rabbits (3.0–3.5 kg). Next, ∼40% of rabbits’ blood volume was removed producing HS (MAP∼20 mmHg). 15 min later, rabbits were resuscitated with a limited volume (12.5 ml/kg) of rabbit whole blood (FWB), rabbit fresh frozen plasma (FFP), or 5% human albumin (ALB) to a target pressure (MAP) of 60 mmHg (n=8/grp) and monitored for 2hrs. Liver bleeding time was measured at baseline and 10 min after HR. Subsequently, animals were fully resuscitated (blood + LR), surgically repaired, and recovered for 8 days. An untreated group (n = 6) was also included. Results: Following HS, lactate and base deficit levels were increased to 9.2 ± 0.3 and 12.2 ± 2.5 mM respectively with no difference among groups. A lower volume of FWB volume was required to reach the target MAP (p < 0.05 vs. ALB) but MAP declined during the HR period (p < 0.01 vs. ALB). FWB provided higher hematocrit and platelets but it did not reduce lactate level faster than other fluids. Beside higher fibrinogen, no differences were found in hemostatic or resuscitative effects of FFP vs. ALB. Bleeding time was prolonged with ALB and FFP fluids but unchanged with FWB. Untreated rabbits died during shock or shortly after. All treated rabbits except one recovered and lived for 8 days with normal blood tests and similar tissue histology. Conclusions: Two hours of HR using a limited volume of FWB, FFP or ALB led to full recovery and long-term survival of rabbits subjected to HS. Apart from bleeding time, no clinically significant differences were found among the three fluids. Five percent human albumin solutions are isotonic, iso-oncotic, ready-to-use, stable, and compatible with all blood types and should be considered for prehospital resuscitation where blood products are not available or not accepted. Address reprint requests to Bijan S. Kheirabadi, PhD, 3650 Chambers Pass, BHT2, Bldg. 3610, Fort Sam Houston, TX 78234. E-mail: Bijan.s.kheirabadi.civ@mail.mil Received 29 August, 2019 Revised 13 September, 2019 Accepted 29 October, 2019 This work was funded solely by the US Army Medical Research and Development Command. Disclaimer: The opinions or assertions expressed herein are the private views of the authors and are not to be construed as official or as reflecting the views of the US Department of Defense. DISCLOSURE: The authors have no conflict of interest to report. This manuscript is not an endorsement of any commercial products by the authors or the U.S. Army. The funding for this work was provided solely by the US Army Medical Research and Development Command. © 2019 by the Shock Society

The Prognostic Value of Presepsin For Sepsis in Abdominal Surgery: A Prospective Study Introduction: Rapid diagnosis accompanied by appropriate treatment is essential in the therapy of sepsis. However, there is no blood marker available, which reliably predicts sepsis and associated mortality. Therefore, the aim of the present study was to evaluate presepsin and endotoxin in comparison with established blood markers in patients undergoing emergency visceral surgery for abdominal infection. Patients and Methods: This prospective study included 31 patients with abdominal infection undergoing emergency surgery between March and August 2014. The Sepsis-2 and Sepsis-3 definitions of sepsis were used. Blood markers (presepsin, endotoxin, C-reactive protein, procalcitonin (PCT), interleukin 6 (IL-6), white blood count) were analyzed preoperatively and correlated with the clinical course and mortality. Additionally, a combination of the three markers, which performed best, was tested. Results: Twenty patients (64.5%) in the analyzed cohort developed sepsis from an abdominal focus according to the latest sepsis definition. Out of the analyzed blood markers, presepsin exhibited the highest area under the curve, sensitivity, and specificity for the prediction of the development of sepsis. Moreover, presepsin had the highest predictive value for mortality as opposed to both endotoxin and previously established blood markers (i.e., PCT, IL-6). The multimarker approach, which included PCT, IL-6, and presepsin, showed no additional predictive value over presepsin alone. Conclusion: The present study suggests that presepsin is a novel predictor of sepsis and mortality from sepsis in patients undergoing surgery for intra-abdominal infections. The findings of the present study should be validated in a larger cohort. Address reprint requests to Martin K. Angele, MD, FACS, Department of General, Visceral and Transplant Surgery, Ludwig-Maximilians-University Munich, Marchioninistr. 15, 81377 Munich, Germany. E-mail: martin.angele@med.uni-muenchen.de Received 13 May, 2019 Revised 17 July, 2019 Accepted 29 October, 2019 FB and SS contributed equally to this work. The authors report no conflicts of interest. © 2019 by the Shock Society

Plasma miR-370-3p As a Biomarker of Sepsis-Associated Encephalopathy, The Transcriptomic Profiling Analysis of Microrna-Arrays From Mouse Brains The diagnosis of sepsis-associated encephalopathy (SAE), an alteration of conscious from sepsis, is difficult due to the similarity to altered states of conscious that occur from other causes. Transcriptomic analyses between mouse-brains at 24 h after cecal ligation and puncture (CLP) (SAE brain as evaluated by SHIRPA score) and at 120 h post-CLP (survivor) were performed to discover the SAE biomarker. Then, candidate microRNAs (miRs) were validated in mouse and patient samples. As such, increased miR-370-3p in SAE mouse-brains (compared with recovery phase) was demonstrated by transcriptomic miR-profiling and was highly expressed in brain (but not other organs) of 24h-post-CLP mice. Plasma miR-370-3p also increased in CLP but was non-detectable in bilateral-nephrectomy (BiNx, a representative model of acute uremic encephalopathy) despite blood brain barrier permeability defect (determined by plasma s100β and Evan blue dye assay) in both conditions. In parallel, high plasma miR-370-3p was demonstrated in patients with SAE (but not sepsis alone or uremia) suggesting the specificity toward SAE. The association among TNF-α, miR-370-3p and brain apoptosis was demonstrated by i) high serum TNF-α and increased brain apoptosis in SAE mice, ii) TNF-α (but not other cytokines) activated miR-370-3p expression in PC-12 neuron cell and iii) increased cell apoptosis in miR-370-3p transfected PC-12 after incubation with TNF-α. In conclusion, miR-370-3p increased in brain and plasma of SAE mice but not uremic encephalopathy. Perhaps, TNF-α enhances cell susceptibility toward brain apoptosis in SAE, in part, through miR-370-3p induction in neuron. Our pilot-results in patients with SAE supported the possibility that plasma miR-370-3p is an interesting SAE biomarker candidate. Further studies are warranted. Address reprint requests to Asada Leelahavanichkul, Immunology Unit, Department of Microbiology, Chulalongkorn University, Bangkok 10330, Thailand. E-mail: aleelahavanit@gmail.com Received 10 August, 2019 Revised 29 August, 2019 Accepted 24 October, 2019 Declarations: Ethics approval and consent to participate: This project was approved by the Institutional Review Board of the Faculty of Medicine, Chulalongkorn University, which waived the need for informed consent, as the study was observational and performed for routine follow-up (IRB 113/60). Consent for publication: Not applicable Availability of data and material: Not applicable Funding: This work was supported by Thailand Government Fund (RSA-6080023), Thailand Research Fund (RES_61_202_30_022), National Research Council of Thailand (Graduate studies) and Ratchadaphiseksomphot Endowment Fund 2017 (76001-HR). Authors’ contributions: Not applicable Conflicts of interest: None Supplemental digital content is available for this article. Direct URL citation appears in the printed text and is provided in the HTML and PDF versions of this article on the journal's Web site (www.shockjournal.com). Supplemental digital content is available for this article. Direct URL citations appear in the printed text and are provided in the HTML and PDF versions of this article on the journal's Website (www.shockjournal.com). © 2019 by the Shock Society

CA1 Hippocampal Pyramidal Cells in Rats, resuscitated from 8 minutes of Ventricular Fibrillation Cardiac Arrest, recover after 20 weeks of Survival: A Retrospective Pilot Study Purpose: The CA1 region of the hippocampus is specifically vulnerable to global ischemia. We hypothesized that histopathological outcome in a ventricular fibrillation cardiac arrest (VFCA) rat model depends on the time point of the examination. Methods: Male Sprague-Dawley rats were put into VFCA for 8 min, received chest compressions for 2 min and were defibrillated to achieve return of spontaneous circulation. Animals surviving for 80 min, 14 days and 140 days were compared to controls. Viable neurons were counted in a 500 μm sector of the CA1 region and layer thickness measured. Microglia cells and astrocytes were counted in a 250x300 μm2 aspect. Results: Control and 80 min surviving animals had similar numbers of pyramidal neurons in the CA1 region. In 14 and 140 days survivors neuron numbers and layer thickness were severely diminished compared to controls (p < 0.001). Two thirds of the 140 days survivors showed significantly more viable neurons than the last third. Microglia was increased in 14 days survivors compared to controls and 140 days survivors, while astrocytes increased in 14 days and 140 days survivors compared to controls (p < 0.001). 140 days survivors had significantly higher astrocyte counts compared to 14 days survivors. Conclusions: The amount and type of brain lesions present after global ischemia depend on the survival time. A consistent reduction in pyramidal cells in the CA1 region was present in all animals 14 days after VFCA, but in two-thirds of animals a repopulation of pyramidal cells seems to have taken place after 140 days. Address reprint requests to Wolfgang Weihs, DMV, Department of Emergency Medicine, Medical University of Vienna, Waehringer Guertel 18-20,6D, 1090 Vienna, Austria. E-mail: wolfgang.weihs@meduniwien.ac.at. Received 8 August, 2019 Revised 28 August, 2019 Accepted 16 October, 2019 Ethics approval and consent to participate: The experimental protocol was approved by the responsible Animal Care and Use Committee (GZ 0064.11/3b/2011). Experiments were conducted in compliance with EU regulations for animal experimentation and in accordance with ARRIVE guidelines [41]. In this study brain lesions of an 8 min VFCA rat model were analyzed. Consent for publication: Not applicable. Availability of data and material: The datasets generated and/or analyzed during the current study are available from the corresponding author on reasonable request. Competing interests: None of the authors has any actual or potential conflict of interest including any financial, personal or other relationships with other people or organizations within three years of beginning the submitted work that could inappropriately influence, or be perceived to influence, his/her work. Funding: The study was made possible through the generous financial support of the Austrian Science Fund (FWF) [P 24824–824]. The Austrian Science Fund had no involvement in the development of the study design, in the collection, analysis or interpretation of data, in the writing of the report or in the decision to submit the article for publication. The Austrian Science Fund (FWF) requires all project leaders and FWF workers to make their publications freely available through open access. Authors’ contributions: WW, substantial contributions to conception and design, acquisition of data, and analysis and interpretation of data; performance of research (histological examination), drafting of the article, its critical revision; writing of the paper and final approval of the version to be published. AW, FE, IM, performance of research (resuscitation model),acquisition and interpretation of data; EL, CS, CC, performance of research (resuscitation model), AK, UT, assistance with histological examination, BB, immunohistochemical stainings, HH Statistics, MH, AT, substantial contributions to conception and design, AK, responsible veterinarian for animal keeping and housing SH, histological examination, drafting of the article, all co-authors, critical revision of the article as to important intellectual content; and final approval of the version to be published. Supplemental digital content is available for this article. Direct URL citation appears in the printed text and is provided in the HTML and PDF versions of this article on the journal's Web site (www.shockjournal.com). This is an open access article distributed under the Creative Commons Attribution License 4.0 (CCBY), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. http://creativecommons.org/licenses/by/4.0 © 2019 by the Shock Society

Association Between Perfusate Oxygenation and Acute Lung Injury in Tetralogy of Fallot Surgery Purpose: Little is known regarding precise estimates of the association between perfusate oxygenation (PpO2) and acute lung injury (ALI) following tetralogy of Fallot repair. The objective is to investigate PpO2 and the risk of ALI following tetralogy of Fallot repair in pediatric patients. Methods: We conducted a nested case-control study within a prospective Chinese TedaICH cohort including 134 ALI patients aged 1 month to 18 years undergoing complete repair of tetralogy of Fallot, and each was matched to 2 controls. We selected the highest PpO2 during aortic crossclamp as the exposure. Conditional logistic regression was used to quantify the association between PpO2 and overall ALI risk by covariates of interest. We identified and integrated the risk covariates to build ALI nomograms and internally validated the nomograms using bootstrapping. Results: After adjusting for covariates, continuously and categorically higher PpO2 values were associated with ALI risk (all p < 0.05), especially for those with a z-score of pulmonary annulus < -4.0 (p = 0.002), McGoon ratio < 1.5 (p = 0.029), and major aortopulmonary collateral arteries (p = 0.005), despite no statistical heterogeneity (all p interaction >0.05). Younger age, lower oxyhemoglobin saturation, untreated minor aortopulmonary collateral arteries, transannular patch, larger transpulmonary gradient, major transfusion, and longer cardiopulmonary bypass time were independent risk factors for ALI (all p < 0.05). Combining the PpO2 nomogram provided further risk discriminative information on ALI diagnosis compared with the covariate-based nomogram alone in the training cohort (AUC 0.865, 95% CI [0.828 to 0.903] vs 0.869 [0.832 to 0.906], respectively) with no statistical significance (p = 0.445). Conclusions: The findings suggested an association between high PpO2 and ALI risk, and more importance should be attached to independent risk factors for ALI. Address reprint requests to Zhi-gang Liu, MD, PhD, Department of Cardiovascular Surgery, Graduate School, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100730, P.R China. E-mail: liuzgtich@sina.com, Yong-feng Shao, MD, PhD, Department of Cardiovascular Surgery, the First Affiliated Hospital of Nanjing Medical University, Nanjing 210038, P.R China. E-mail: yfshaojph@sina.com, Hong Liu, MD, PhD, Department of Cardiovascular Surgery, the First Affiliated Hospital of Nanjing Medical University, Nanjing 210038, P.R China. E-mail: dr.hongliu@foxmail.com Received 26 August, 2019 Revised 23 September, 2019 Accepted 25 October, 2019 Funding/Support: The research was supported by Fundamental Research Funds for the Central Universities (No.3332018189) and National Clinical Key Specialty Construction Projects of China. Conflict of interest: The authors have no conflict of interests. ClinicalTrials.gov: NCT03568357. © 2019 by the Shock Society

Resuscitation Fluids in Septic Shock: A Network Meta-Analysis of Randomized Controlled Trials The aim of this study was to assess the efficacy and safety of various resuscitation fluids in septic shock by adopting a network meta-analysis (NMA). Randomized controlled trials (RCTs) comparing resuscitation fluids in septic shock were carried out by retrieving electronic databases. NMAs of 28-day mortality, 90-day mortality, incidence of acute kidney injury (AKI), and the need for renal replacement therapy (RRT) were conducted using the STATA 15.0 software. Probability-based ranking and surface under cumulative ranking (SUCRA) were performed to identify the optimal resuscitation fluid. Inconsistencies were evaluated by node-splitting analysis and a loop-specific approach. Furthermore, publication bias was analyzed by funnel plots. A total of 13 RCTs were enrolled in the analysis. The NMA results revealed that no significant differences were detected in the outcomes of 28-day mortality and 90-day mortality among various resuscitation fluids. The SUCRAs (the first indicates the best) of 28-day mortality showed that the hypertonic sodium chloride/hydroxyethyl starch 40 solution ranked the highest (93.8%), followed by the balanced solution (BS) (69.6%), and albumin (61.9%). On the other hand, the SUCRAs of 90-day mortality revealed that gelatin (GEL) ranked the highest (75.1%), followed by BS (55.1%), and NS (52.4%). The NMA results of AKI demonstrated that high-molecular-weight hydroxyethyl starch (H-HES) was associated with increased risk of AKI in comparison with GEL, BS, and L-HES. The SUCRAs of AKI showed that GEL ranked the highest (74.4%), followed by NS (64.9%), and BS (58.3%). In addition, the NMA results of RRT revealed that H-HES was associated with an increased need for RRT in comparison with BS and NS, and L-HES was associated with increased need of RRT in comparison with BS. The SUCRAs of RRT revealed that NS ranked the highest (91.6%), followed by BS (74.4%) and L-HES (36.1%). No significant inconsistencies were shown by the node-splitting analysis and no publication bias was demonstrated in the funnel plots. In conclusion, BS was determined as the preferred resuscitation fluid for septic shock. Moreover, the use of GEL requires further evaluation. H-HES was associated with a significant risk of AKI and RRT, whereas L-HES with an increased need for RRT compared with BS. Thus, both resuscitation fluids should be avoided for septic shock. Address reprint requests to Liangming Liu, State Key Laboratory of Trauma, Burns, and Combined Injury, Department 2, Research Institute of Surgery, Daping Hospital, Army Medical University, Chongqing 400042, P.R. China. E-mail: liangmingliu@yahoo.com. Co-correspondence: Tao Li, PhD, MD, State Key Laboratory of Trauma, Burns, and Combined Injury, Department 2, Research Institute of Surgery, Daping Hospital, Army Medical University, Chongqing 400042, P.R. China. E-mail: lt200132@163.com. Received 11 August, 2019 Revised 16 September, 2019 Accepted 16 October, 2019 This work was supported by the Military Key Projects (Grant No. AWS16J032). The authors report no conflicts of interest. Supplemental digital content is available for this article. Direct URL citation appears in the printed text and is provided in the HTML and PDF versions of this article on the journal's Web site (www.shockjournal.com). © 2019 by the Shock Society

Shock, not Blood Pressure or Shock, Determines the need for Thoracic Damage Control Following Penetrating Trauma Background: Damage control laparotomy has increased survival for critically injured patient with penetrating abdominal trauma. There has been a slower adoption of a damage control strategy for thoracic trauma despite the considerable mortality associated with emergent thoracotomy for patients in profound shock. We postulated admission physiology, not blood pressure or shock index, would identify patients who would benefit from thoracic damage control. Study Design: Retrospective trauma registry review from 2002 to 2017 at a busy, urban trauma center. 301 patients with penetrating thoracic trauma operated on within 6 hours of admission were identified. Of those 66 (21.9%) required thoracic damage control and comprise the study population. Results: Compared to the non-damage control group, the 66 damage control patients had significantly higher ISS, chest AIS, lactate and base deficit, and lower pH and temperature. In addition, the DCTS group had significantly more gunshot wounds, transfusions, concomitant laparotomies, vasoactive infusions, and shorter time to the operating room. Notably, however, there were no significant differences in admission systolic blood pressure or shock index between the groups. Once normal physiology was restored, chest closure was performed 1.7 (0.7) days after the index operation. Mortality for thoracic damage was 15.2%, significantly higher than the 4.3% in the non-damage control group. Over two-thirds of damage control deaths occurred prior to chest closure. Conclusions: Mortality in this series of severely injured, profoundly physiologically altered patients undergoing thoracic damage control is substantially lower than previously reported. Rather than relying on blood pressure and shock index, early recognition of shock identifies patients in whom thoracic damage control is beneficial. Address reprint requests to James V. O’Connor, MD, R Adams Cowley Shock Trauma Center, University of Maryland School of Medicine, 22 S Greene Street, Baltimore, MD 21201. E-mail: james.oconnor@som.umaryland.edu Received 30 August, 2019 Revised 18 September, 2019 Accepted 24 October, 2019 The authors report no conflicts of interest. © 2019 by the Shock Society

Toll like receptor 2 and 9 expression on circulating neutrophils is associated with increased mortality in critically ill patients Background: Toll-like receptors (TLRs) play an important role in inflammatory processes in critically ill patients by binding to pathogen-associated molecular patterns and danger-associated molecular patterns (DAMPs). Whether neutrophil or monocyte TLR expression patterns are associated with outcome in critical illness is unknown. Objectives: To answer this question, we conducted a prospective, observational study including 215 consecutive patients admitted to a medical ICU at a tertiary care center. Methods: Blood was drawn at admission and expression of TLR-2, TLR-4, and TLR-9 on neutrophils and monocytes were analyzed by flow cytometry. Results: Median Acute Physiology and Chronic Health Evaluation II (APACHE II) score was 19, and 30-day mortality was 26%. TLR-2 expression on neutrophils was associated with APACHE II, Simplified Acute Physiology Score II, and Sepsis-related Organ Failure Assessment score. TLR-2 (P < 0.001) and TLR-9 (P < 0.05) expression on neutrophils was significantly higher in nonsurvivors. In contrast, neutrophil TLR-4 expression and monocyte TLR expression were not associated with survival. Neutrophil TLR-2 (OR 3.8; 95% CI 1.4–10.2; P < 0.05) and TLR-9 (OR 4.0; 95% CI 2.0–8.1; P < 0.001) expression in the third tertile predicted mortality independent from APACHE II, serum lactate, serum creatinine, and procalcitonin, respectively. Conclusion: We provide evidence for prognostic properties of neutrophil TLR-2 and TLR-9 expression regarding 30-day mortality in unselected critically ill patients, independent from baseline clinical characteristics, and laboratory values. These findings suggest that specific TLR-dependent activation of the innate immune system via neutrophils possibly caused by cell damage and release of otherwise intracellular components may play a significant role in the pathophysiology of critical illness. Address reprint requests to Walter S. Speidl, MD, Department of Internal Medicine II, Medical University of Vienna, Waehringer Guertel 18-20, Vienna, Austria. E-mail: Walter.Speidl@meduniwien.ac.at Received 7 August, 2019 Revised 28 August, 2019 Accepted 7 October, 2019 Conflicts of interest: the authors declare no conflict of interest. Availability of materials and data: The datasets generated during and/or analyzed during the present study are available from the corresponding author on reasonable request. Author contributions: K.A.K. and W.S.S. designed the study and were involved in data analysis and interpretation. A.N., K.H., J.W., and G.H. were strongly involved in analysis and interpretation of data. D.F.D., C.Z., M.K., and S.P.K. were strongly involved in data acquisition. M.L., K.A.K., and W.S.S. drafted the manuscript. D.F.D., C.Z., M.K., S.P.K., A.N., K.H., J.W., and G.H. critically revised the manuscript. All authors gave final approval of the version submitted. Each author has participated sufficiently in the work to take public responsibility for appropriate portions of the content and agreed to be accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved. Competing interests: All authors declare no competing interests. © 2019 by the Shock Society