Satoshi Fujimi

Increased CD4+ CD25+ T regulatory cell activity in trauma patients depresses protective Th1 immunity

Objectives:We recently reported increased CD4+ CD25+ T regulatory (Treg) activity after burn injury in mice. This study sought to determine if Tregs mediate the reduction in TH1-type immunity after serious injury in man and if Treg function is altered by injury. Methods:Peripheral blood was withdrawn from 19 consenting adult patients (35.1 ± 16.3 years of age) with Injury Severity Scores (ISS) 36.6 ± 13.9 on days 1 and 7 after trauma and from 5 healthy individuals. CD4+ T cells were purified and sorted into Treg (CD25high) and Treg-depleted populations. After activation of cells with anti-CD3/CD28 antibody, production of the TH1-type cytokine IFNγ, TH2-type cytokines (IL-4 and IL-5), and the inhibitory cytokine IL-10 was measured using cytometric bead arrays. Treg activity was measured by in vitro suppression of autologous CD4+ T cell proliferation. Results:All patients survived, 9 (47%) developed infection postinjury. IFNγ production by patient CD4+ T cells was decreased on day 1 and day 7, when compared with healthy controls. However, when Tregs were depleted from the CD4+ T cells, the IFNγ production increased to control levels. Tregs were the chief source of IL-4 and IL-5 as well as IL-10. Treg suppression of T cell proliferation increased significantly from day 1 to day 7 after injury. Conclusions:We demonstrate for the first time that human Tregs are increased in potency after severe injury. Most significantly, Tregs are important mediators of the suppression of T cell activation and the reduction in TH1 cytokine production found after injury.

Enhanced TLR4 reactivity following injury is mediated by increased p38 activation.

Severe injury primes the innate‐immune system for increased Toll‐like receptor 4 (TLR4)‐induced proinflammatory cytokine production by macrophages. In this study, we examined changes in TLR4 signaling pathways in splenic macrophages from burn‐injured or sham mice to determine the molecular mechanism(s) responsible for the increased TLR4 responsiveness. Using flow cytometry and specific antibodies, we first looked for injury‐induced changes in the expression levels of several TLR‐associated signaling molecules. We found similar levels of myeloid differentiation primary‐response protein 88 (MyD88) and interleukin‐1 receptor‐associated kinase‐M (IRAK‐M) and somewhat lower levels of total p38, extracellular signal‐regulated kinase (ERK), and stress‐activated protein kinase (SAPK)/c‐jun N‐terminal kinase (JNK) mitogen‐activated protein kinases (MAPKs) in burn compared with sham macrophages. However, with the use of antibodies specific for the phosphorylated (activated) forms of the three MAPKs, we found that macrophages from burn mice showed a twofold increase in purified lipopolysaccharide (LPS)‐stimulated p38 activation as compared with cells from sham mice on days 1 and 7 post‐injury, whereas ERK and SAPK/JNK activation was increased by burn injury only on day 1. Using the specific p38 inhibitor (SB203580), we confirmed that the increase in tumor necrosis factor α production by LPS‐stimulated burn macrophages requires p38 activation. Although we demonstrated that injury increases macrophage TLR4 mRNA expression and intracellular expression of TLR4‐myeloid differentiation protein‐2 (MD‐2) protein, macrophage cell‐surface expression of TLR4‐MD‐2 was not changed by burn injury. Our results suggest that the injury‐induced increase in TLR4 reactivity is mediated, at least in part, by enhanced activation of the p38 signaling pathway.

Efficacy and safety of anticoagulant therapy in three specific populations with sepsis: a meta‐analysis of randomized controlled trials

Essentials Most anticoagulant therapy has failed to demonstrate a survival benefit in the overall sepsis population. We conducted separate meta‐analyses of anticoagulant therapy in three different populations. Survival benefit was observed only in the septic disseminated intravascular coagulation (DIC) population. Further randomized controlled trials should focus on specific populations with septic DIC.

Injury Enhances Resistance to Escherichia coli Infection by Boosting Innate Immune System Function

Major injury is widely thought to predispose the injured host to opportunistic infections. This idea is supported by animal studies showing that major injury causes reduced resistance to polymicrobial sepsis induced by cecal ligation and puncture. Although cecal ligation and puncture represents a clinically relevant sepsis model, we wanted to test whether injury might also lead to greater susceptibility to peritoneal infection caused by a single common pathogen, Escherichia coli. Contrary to our expectation, we show herein that the LD50 for sham-injured mice was 103 CFU of E. coli, whereas the LD50 for burn-injured mice was 50 × 103 CFU at 7 days postinjury. This injury-associated enhanced resistance was apparent as early as 1 day after injury, and maximal resistance was observed at days 7 and 14. We found that burn-injured mice had higher numbers of circulating neutrophils and monocytes than did sham mice before infection and that injured mice were able to recruit greater numbers of neutrophils to the site of infection. Moreover, the peritoneal neutrophils in burn-injured mice were more highly activated than neutrophils from sham mice as determined by Mac-1 expression, superoxide generation, and bactericidal activity. Our findings suggest that the enhanced innate immune response that develops following injury, although it is commonly accepted as the mediator of the detrimental systemic inflammatory response syndrome, may also, in some cases, benefit the injured host by boosting innate immune antimicrobial defenses.

Murine dendritic cell antigen-presenting cell function is not altered by burn injury

Severe injury disrupts normal immune regulation causing a transient hyperinflammatory reaction and suppressed adaptive immune function. This report addresses the potential contribution of dendritic cells (DC) to changes in adaptive immune function after injury by specifically measuring injury‐induced changes in splenic DC numbers and subsets, cell‐surface markers, TLR responses, and APC function. Using a mouse burn injury model, we found that injury did not markedly alter the relative percentage of lymphoid, myeloid, or plasmacytoid DC in the spleens of burn‐injured mice. Moreover, we did not observe a significant reduction in cell‐surface expression of several major costimulatory molecules, CD40, CD80, CD86, programmed death 1 ligand, ICOS ligand, and B7‐H3, on DC. Instead, we observed increased cell‐surface expression of CD86 at 1 day after injury with no significant changes in costimulatory molecule expression at 7 days after injury, suggesting that burn injury causes an early activation of DC. In addition, injury did not suppress DC reactivity to TLR2, TLR4, or TLR9 agonists. Most important, DC prepared from injured mice were able to present peptide antigen to naïve OTII TCR transgenic CD4+ T cells as efficiently and effectively as DC from sham‐injured mice. We also found that CD4 T cells stimulated with antigen presented by DC from sham or burn mice showed similar levels of IL‐2, IFN‐γ, IL‐10, and IL‐13 production. Taken together, these findings support the conclusion that DC do not acquire a suppressive phenotype following severe injury in mice.

Trauma-hemorrhage inhibits splenic dendritic cell proinflammatory cytokine production via a mitogen-activated protein kinase process.

Although splenic dendritic cell (DC) functions are markedly altered following trauma-hemorrhage, the mechanism(s) responsible for the altered DC functions remains unknown. We hypothesized that trauma-hemorrhage inhibits DC function via suppressing toll-like receptor 4 (TLR4) expression and mitogen-activated protein kinases (MAPKs). To examine this, male C3H/HeN (6-8 wk) mice were randomly assigned to sham operation or trauma-hemorrhage. Trauma-hemorrhage was induced by midline laparotomy and approximately 90 min of hypotension [blood pressure (BP) 35 mmHg], followed by fluid resuscitation (4x the shed blood volume in the form of Ringer lactate). Two hours later, mice were euthanized, splenic DCs were isolated, and the changes in their MAPK activation, TLR4-MD-2 expression, and ability to produce cytokines were measured. The results indicate that trauma-hemorrhage downregulated the lipopolysaccharide (LPS)-induced MAPK activation in splenic DCs. In addition to the decrease in MAPK activation, surface expression of TLR4-MD-2 was suppressed following trauma-hemorrhage. Furthermore, LPS-induced cytokine production from splenic DCs was also suppressed following trauma-hemorrhage. These findings thus suggest that the decrease in TLR4-MD-2 and MAPK activation may contribute to the LPS hyporesponsiveness of splenic DCs following trauma-hemorrhage. Hyporesponsiveness of splenic DCs was also found after stimulation with the TLR2 agonist zymosan. Our results may thus explain the profound immunosuppression that is known to occur under those conditions.

The Survival Benefit of a Novel Trauma Workflow that Includes Immediate Whole-body Computed Tomography, Surgery, and Interventional Radiology, All in One Trauma Resuscitation Room: A Retrospective Historical Control Study.

Objective: The aim of this study was to evaluate the impact of a novel trauma workflow, using an interventional radiology (IVR)–computed tomography (CT) system in severe trauma. Background: In August 2011, we installed an IVR-CT system in our trauma resuscitation room. We named it the Hybrid emergency room (ER), as it enabled us to perform all examinations and treatments required for trauma in a single place. Methods: This retrospective historical control study conducted in Japan included consecutive severe (injury severity score ≥16) blunt trauma patients. Patients were divided into 2 groups: Conventional (from August 2007 to July 2011) or Hybrid ER (from August 2011 to July 2015). We set the primary endpoint as 28-day mortality. The secondary endpoints included cause of death and time course from arrival to start of CT and surgery. Multivariable logistic regression analysis adjusted for clinically important variables was performed to evaluate the clinical outcomes. Results: We included 696 patients: 360 in the Conventional group and 336 in the Hybrid ER group. The Hybrid ER group was significantly associated with decreased mortality [adjusted odds ratio (OR), 0.50 (95% confidence interval, 95% CI, 0.29–0.85); P = 0.011] and reduced deaths from exsanguination [0.17 (0.06–0.47); P = 0.001]. The time to CT initiation [Conventional 26 (21 to 32) minutes vs Hybrid ER 11 (8 to 16) minutes; P < 0.0001] and emergency procedure [68 (51 to 85) minutes vs 47 (37 to 57) minutes; P < 0.0001] were both shorter in the Hybrid ER group. Conclusion: This novel trauma workflow, comprising immediate CT diagnosis and rapid bleeding control without patient transfer, as realized in the Hybrid ER, may improve mortality in severe trauma.

Screening itself for disseminated intravascular coagulation may reduce mortality in sepsis: A nationwide multicenter registry in Japan

OBJECTIVES Screening of patients with sepsis for disseminated intravascular coagulation (DIC) has been recommended in several guidelines. However, DIC screening is still not widely accepted as an essential component of sepsis management, partly because of a lack of evidence that DIC screening has an effect on mortality. We investigated whether DIC screening was associated with a survival benefit in patients with sepsis. DESIGN Post hoc analysis of a nationwide multicenter retrospective cohort study. SETTING 42 intensive care units in Japan. PARTICIPANTS 2663 adult patients diagnosed as having severe sepsis: 1893 (71.1%) patients were considered candidates for and 770 (28.9%) patients were not considered candidates for International Society of Thrombosis and Hemostasis (ISTH) overt DIC screening on ICU day 1. MAIN OUTCOME MEASURES The primary outcome measure was all-cause in-hospital mortality. Patients were stratified according to whether DIC screening was performed at the time of ICU admission (day 1) to investigate the survival effect associated with DIC screening. We also evaluated survival benefit by classifying patients according to whether DIC screening was performed on day 1 and repeated on day 3. Effects of screening on mortality were assessed using Cox proportional hazards models adjusted by the inverse probability of treatment weighting (IPTW) method using propensity scoring. RESULTS After adjustment for imbalances, ISTH overt DIC screening on day 1 was associated with significantly lower mortality (IPTW-adjusted HR: 0.836; 95% confidence interval [CI]: 0.711-0.984), and this association became even stronger when ISTH overt DIC screening was repeated on day 3 (IPTW-adjusted HR: 0.727; 95% CI: 0.597-0.884). Besides, we observed an almost comparable effect on mortality associated with DIC screening using the Japanese Association for Acute Medicine criteria. CONCLUSION DIC screening was associated with a reduction in mortality in patients with sepsis. This association could be even stronger by repeating DIC screening.

Impact of Gram stain results on initial treatment selection in patients with ventilator-associated pneumonia: a retrospective analysis of two treatment algorithms

BackgroundVentilator-associated pneumonia (VAP) is a common and serious problem in intensive care units (ICUs). Several studies have suggested that the Gram stain of endotracheal aspirates is a useful method for accurately diagnosing VAP. However, the usefulness of the Gram stain in predicting which microorganisms cause VAP has not been established. The purpose of this study was to evaluate whether a Gram stain of endotracheal aspirates could be used to determine appropriate initial antimicrobial therapy for VAP.MethodsData on consecutive episodes of microbiologically confirmed VAP were collected from February 2013 to February 2016 in the ICU of a tertiary care hospital in Japan. We constructed two hypothetical empirical antimicrobial treatment algorithms for VAP: a guidelines-based algorithm (GLBA) based on the recommendations of the American Thoracic Society-Infectious Diseases Society of America (ATS-IDSA) guidelines and a Gram stain-based algorithm (GSBA) which limited the choice of initial antimicrobials according to the results of bedside Gram stains. The GLBA and the GSBA were retrospectively reviewed for each VAP episode. The initial coverage rates and the selection of broad-spectrum antimicrobial agents were compared between the two algorithms.ResultsDuring the study period, 219 suspected VAP episodes were observed and 131 episodes were assessed for analysis. Appropriate antimicrobial coverage rates were not significantly different between the two algorithms (GLBA 95.4% versus GSBA 92.4%; p = 0.134). The number of episodes for which antimethicillin-resistant Staphylococcus aureus agents were selected as an initial treatment was larger in the GLBA than in the GSBA (71.0% versus 31.3%; p < 0.001), as were the number of episodes for which antipseudomonal agents were recommended as an initial treatment (70.2% versus 51.9%; p < 0.001).ConclusionsAntimicrobial treatment based on Gram stain results may restrict the administration of broad-spectrum antimicrobial agents without increasing the risk of treatment failure.Trial registrationUMIN-CTR, UMIN000026457. Registered 8 March 2017 (retrospectively registered).

The possibility of the treatment for long-acting injectable antipsychotics induced severe side effects

We present the case of a 47-year-old man with schizophrenia who developed acute and persistent circulatory failure after receiving injections of paliperidone palmitate. We measured blood concentrations of paliperidone and performed resection of hip tissues, where paliperidone palmitate was suspected to be present, in order to reduce the side effects. Unfortunately, the resection could not save the patient from prolonged and severe side effects and he died of multiple organ failure. We suggest that resection of the tissues suspected of containing paliperidone palmitate can help reduce its severe side effects. However, identifying the site of injection is essential.