Depressed interleukin-12-producing activity by monocytes correlates with adverse clinical course and a shift toward Th2-type lymphocyte pattern in severely injured male trauma patients

Improving geriatric outcomes through nutritional and immunonutritional strategies: Focus on surgical setting by a comprehensive evidence review

The aging population worldwide has led to an increased request for surgical interventions in older, geriatric, and frail patients. However, all the physiological changes related to aging are associated with many challenges in the perioperative period, strongly impacting surgical outcomes. Nutritional status plays a pivotal role in determining the resilience of older adults to surgical stress and their ability to recover postoperatively. It is well known that malnutrition, a prevalent concern in geriatrics, is linked to increased adverse outcomes, including morbidity and mortality. Recognizing the significance of preoperative nutritional screening, assessment, diagnosis, intervention, and monitoring is essential for optimizing surgical outcomes. In this context, immunonutrition, which involves the supplementation of specific nutrients to modulate immune responses, emerges as a promising strategy to mitigate the increased inflammatory response observed in geriatric surgical patients. This study reviews current literature on the impact of nutrition and immunonutrition on surgical outcomes in geriatrics, highlighting the potential benefits in terms of reduced complications, enhanced wound healing, and shortened hospital stays. Recognizing and addressing the specific nutritional needs of older persons undergoing surgery is essential for promoting successful surgical outcomes and improving overall quality of life in this vulnerable population.

The role of T-lymphocytes in central nervous system diseases

The central nervous system (CNS) has been considered an immunologically privileged site. In the past few decades, research on inflammation in CNS diseases has mostly focused on microglia, innate immune cells that respond rapidly to injury and infection to maintain CNS homeostasis. Discoveries of lymphatic vessels within the dura mater and peripheral immune cells in the meningeal layer indicate that the peripheral immune system can monitor and intervene in the CNS. This review summarizes recent advances in the involvement of T lymphocytes in multiple CNS diseases, including brain injury, neurodegenerative diseases, and psychiatric disorders. It emphasizes that a deep understanding of the pathogenesis of CNS diseases requires intimate knowledge of T lymphocytes. Aiming to promote a better understanding of the relationship between the immune system and CNS and facilitate the development of therapeutic strategies targeting T lymphocytes in neurological diseases.

Major Surgical Trauma Impairs the Function of Natural Killer Cells but Does Not Affect Monocyte Cytokine Synthesis

Major traumatic and surgical injury increase the risk for infectious complications due to immune dysregulation. Upon stimulation with interleukin (IL) 12 by monocyte/macrophages, natural killer (NK) cells release interferon (IFN) γ that supports the elimination of the pathogen. In the present study, we investigated the impact of invasive spine surgery on the relationship between monocytes and NK cells upon exposure to Staphylococcus aureus. Mononuclear cells and serum were isolated from peripheral blood of patients before and up to 8 d after surgery and stimulated with inactivated S. aureus bacteria. NK cell and monocyte function were determined by flow cytometry. NK cells continuously lost their ability to produce IFN-γ during the first week after surgery independently from monocyte-derived IL-12 secretion. IFN-γ synthesis was minimal on day 8 and was associated with decreased expression of the IL-12 receptor and activation of transcription factors required for IFNG gene transcription. Addition of recombinant IL-12 could at least partially restore NK cell function. Pre-operative levels of growth/differentiation factor (GDF) 15 in the serum correlated with the extent of NK cell suppression and with hospitalization. Thus, NK cell suppression after major surgery might represent a therapeutic target to improve the immune defense against opportunistic infections.

Reduced phagocytosis, ROS production and enhanced apoptosis of leukocytes upon alcohol drinking in healthy volunteers

Background

Alcohol drinking is associated with a serious risk of developing health problems as well as with a large number of traumatic injuries. Although chronic alcohol misuse is known to contribute to severe inflammatory complications, the effects of an acute alcohol misuse are still unclear. Here, the impact of acute alcohol drinking on leukocyte counts and their cellular functions were studied.

Methods

Twenty-two healthy volunteers (12 female, 10 male) received a predefined amount of a whiskey-cola mixed drink (40% v/v), at intervals of 20 min, over 4 h to achieve a blood alcohol concentration of 1‰. Blood samples were taken before drinking T₀, 2 h (T₂), 4 h (T₄), 6 h (T₆), 24 h (T₂₄) and 48 h (T₄₈) after starting drinking alcohol. Leukocytes, monocytes and granulocyte counts and their functions regarding the production of reactive oxidative species (ROS), phagocytosis and apoptosis were analyzed by flow cytometry.

Results

Total leukocyte counts significantly increased at T₂ and T₄, while granulocyte and monocyte counts decreased at T₄ and T₆ vs. T₀. Monocytes increased significantly at T₂₄ and T₄₈ vs. T₀. While the total number of ROS-producing leukocytes and notably granulocytes significantly increased, in parallel, the intracellular ROS intensity decreased at T₂ and T₆. The numbers of ROS-positive monocytes have shown a delayed modulation of ROS, with a significant reduction in the total number of ROS-producing cells at T₄₈ and a significantly reduced intracellular ROS-intensity at T₂₄. Phagocyting capacity of leukocytes significantly decreased at T₄ and T₆. In general leukocytes, and notably granulocytes demonstrated significantly increased early (T₂), while monocyte exerted significantly increased late apoptosis (T₂₄ and T₄₈).

Conclusions

Alcohol drinking immediately impacts leukocyte functions, while the impact on monocytes occurs at even later time points. Thus, even in young healthy subjects, alcohol drinking induces immunological changes that are associated with diminished functions of innate immune cells that persist for days.

Immunosuppression is Inappropriately Qualifying the Immune Status of Septic and SIRS Patients

Immunosuppression is the most commonly used concept to qualify the immune status of patients with either sterile systemic inflammatory response syndrome (SIRS) or sepsis. In this review we attempt to demonstrate that the concept of immunosuppression is an oversimplification of the complex anti-inflammatory response that occurs in patients dealing with a severe sterile or infectious insult. Particularly, the immune status of leukocytes varies greatly depending on the compartment from where they are derived from. Furthermore, although certain functions of immune cells present in the blood stream or in the hematopoietic organs can be significantly diminished, other functions are either unchanged or even enhanced. This juxtaposition illustrates that there is no global defect. The mechanisms called reprogramming or trained innate immunity are probably aimed at preventing a generalized deleterious inflammatory reaction, and work to maintain the defense mechanisms at their due levels.

Immune capacity determines outcome following surgery or trauma: a systematic review and meta-analysis

Purpose

Immunological functions are altered following physical injury. The magnitude of the immunological response is dependent on the initial injury. However, variability in the immune response exists within and between patients where only some patients are at risk of developing complications such as systemic inflammatory response syndrome after injury. This systematic review and meta-analysis assessed whether lipopolysaccharide (LPS) induced cytokine production capacity of leucocytes can be used as a functional test to predict the risk of developing complications after injury.

Methods

Medline, Embase and Web of Science were systematically searched to identify articles that investigated the association between LPS induced cytokine production capacity in leucocytes and any clinical outcome after surgery or trauma. Where sufficient information was supplied, a meta-analysis was performed to determine the overall clinical outcomes.

Results

A total of 25 articles out of 6765 abstracts identified through the literature search were included in this review. Most articles described a positive association between cytokine production capacity and the development of inflammatory complications (n = 15/25). Coincidingly, the meta-analysis demonstrated that TNFα (Hedges g: 0.63, 95% CI 0.23, 1.03), IL-6 (Hedges g: 0.76, 95% CI 0.41, 1.11) and IL-8 (Hedges g: 0.93, 95% CI 0.46, 1.39) production capacity was significantly higher, one day after injury, in patients who developed inflammatory complications compared to patients who did not following trauma or surgical intervention. No significant difference was observed for IL-1β.

Conclusion

The associations of elevated LPS-induced cytokine production capacity with the risk of developing inflammatory complications are consistent with previous theories that proposed excessive inflammation is accompanied by anti-inflammatory mechanisms that results in a period of immunosuppression and increased risk of secondary complications. However, immunological biomarkers for risk stratification is still a developing field of research where further investigations and validations are required.

Electronic supplementary material

The online version of this article (10.1007/s00068-019-01271-6) contains supplementary material, which is available to authorized users.

Post-operative complications in patients with a significant post-operative decrease in γδT cells

BACKGROUND

It has previously been shown that appropriate distribution of immune cells between different tissues and organs of the body is required for proper function of the immune system. Our previous work demonstrated that surgical trauma in mice induces γδT lymphocyte migration from peripheral blood to the peritoneal lymphoid organs. These described γδT cells have immunoregulatory activity as they suppress the cell-mediated immune response in vitro. We found a similar phenomenon in patients after different surgical operations. In the current study, we analyse post-operative complications in patients with a significant post-operative decrease in γδT cells.

METHODS

We investigated the percentage of γδT cells in peripheral blood of patients undergoing standard surgical procedures (gastric resection, colorectal resection, cholecystectomy and strumectomy) before and 3 days after the operation. The percentage of γδT cells was evaluated by the fluorescence-activated cell sorting cytofluorimeter. Patients were grouped based on the decrease of γδT cells. We compared the number of septic complications in patients with a large and small decrease in γδT cells.

RESULTS

After major surgery in the peritoneal cavity (gastric and colorectal surgery), in the group that had a large decrease in γδT cells we found significantly more septic complications than in the group of patients with small γδT decrease. That effect was not visible after less traumatic surgery.

CONCLUSION

Surgery results in a decreased percentage of γδT lymphocytes in the peripheral human blood which correlates with the number of septic complications. This observation may help to predict post-operative recovery after gastroabdominal surgery.

Circulating growth/differentiation factor 15 is associated with human CD56bright natural killer cell dysfunction and nosocomial infection in severe systemic inflammation

Background

Systemic inflammation induced by sterile or infectious insults is associated with an enhanced susceptibility to life-threatening opportunistic, mostly bacterial, infections due to unknown pathogenesis. Natural killer (NK) cells contribute to the defence against bacterial infections through the release of Interferon (IFN) γ in response to Interleukin (IL) 12. Considering the relevance of NK cells in the immune defence we investigated whether the function of NK cells is disturbed in patients suffering from serious systemic inflammation.

Methods

NK cells from severely injured patients were analysed from the first day after the initial inflammatory insult until the day of discharge in terms of IL-12 receptor signalling and IFN-γ synthesis.

Findings

During systemic inflammation, the expression of the IL-12 receptor β2 chain, phosphorylation of signal transducer and activation 4, and IFN-γ production on/in NK cells was impaired upon exposure to Staphylococcus aureus. The profound suppression of NK cells developed within 24 h after the initial insult and persisted for several weeks. NK cells displayed signs of exhaustion. Extrinsic changes were mediated by the early and long-lasting presence of growth/differentiation factor (GDF) 15 in the circulation that signalled through the transforming growth factor β receptor I and activated Smad1/5. Moreover, the concentration of GDF-15 in the serum inversely correlated with the IL-12 receptor β2 expression on NK cells and was enhanced in patients who later acquired septic complications.

Interpretation

GDF-15 is associated with the development of NK cell dysfunction during systemic inflammation and might represent a novel target to prevent nosocomial infections.

Fund

The study was supported by the Department of Orthopaedics and Trauma Surgery, University Hospital Essen.

Early and dynamic alterations of Th2/Th1 in previously immunocompetent patients with community-acquired severe sepsis: a prospective observational study

BACKGROUND

T helper (Th) cells regulate sepsis processes, including primary pathogen clear and secondary pathogen defence. The objectives of this study were to determine the early and dynamic alterations of Th1 and Th2 populations to community-acquired severe sepsis upon onset among previously immunocompetent patients and whether it was related to clinical outcomes.

METHODS

This prospective observational cohort study was conducted at a general intensive care unit (ICU) of a tertiary teaching hospital in China. Immunocompetent patients with community-acquired severe sepsis within 24 h upon onset were included as septic group. Healthy volunteers and critically ill patients without severe sepsis were recruited as controls. Whole blood was collected on D0, 3rd day (D3) and 7th day (D7) for septic group and once upon enrollment for controls. Th1 and Th2 populations were measured by flow cytometry and assessed for associations with 28-day mortality using cox proportional hazard models. Associations of dynamic alterations of Th cell subpopulations with clinical outcomes were investigated.

RESULTS

This study demonstrated that community-acquired severe sepsis patients (n = 71) had increased Th2/Th1 and Th2 populations, compared to healthy controls (n = 7) and critically ill patients without severe sepsis (n = 7) at admission. Among the septic cohort, values of Th2/Th1 were significantly higher in non-survivors than survivors on D0 (p = 0.04), D3 (p < 0.001) and D7 (p < 0.001). Patients with persistently increasing Th2/Th1 demonstrated the highest mortality (47.1%) and incidence of ICU-acquired infections (64.7%).

CONCLUSIONS

Th2/Th1 was markedly up-regulated with Th2 dominance upon community-acquired severe sepsis onset among previously immunocompetent patients and its persistently dynamic increase was associated with ICU-acquired infections and 28-day death. Trial registration Institutional Ethics Committee of Zhongda Hospital, 2014ZDSYLL086, registered in June 2014-prospectively registered; ClinicalTrials.gov, NCT02883218, registered on 25 Aug 2016-retrospectively registered, https://www.clinicaltrials.gov/ct2/show/NCT02883218?cond=NCT02883218&rank=1.

Neuroimaging Findings in Sepsis-Induced Brain Dysfunction: Association with Clinical and Laboratory Findings

BACKGROUND

Incidence and patterns of brain lesions of sepsis-induced brain dysfunction (SIBD) have been well defined. Our objective was to investigate the associations between neuroimaging features of SIBD patients and well-known neuroinflammation and neurodegeneration factors.

METHODS

In this prospective observational study, 93 SIBD patients (45 men, 48 women; 50.6 ± 12.7 years old) were enrolled. Patients underwent a neurological examination and brain magnetic resonance imaging (MRI). Severity-of-disease scoring systems (APACHE II, SOFA, and SAPS II) and neurological outcome scoring system (GOSE) were used. Also, serum levels of a panel of mediators [IL-1β, IL-6, IL-8, IL-10, IL-12, IL-17, IFN-γ, TNF-α, complement factor Bb, C4d, C5a, iC3b, amyloid-β peptides, total tau, phosphorylated tau (p-tau), S100b, neuron-specific enolase] were measured by ELISA. Voxel-based morphometry (VBM) was employed to available patients for assessment of neuronal loss pattern in SIBD.

RESULTS

MRI of SIBD patients were normal (n = 27, 29%) or showed brain lesions (n = 51, 54.9%) or brain atrophy (n = 15, 16.1%). VBM analysis showed neuronal loss in the insula, cingulate cortex, frontal lobe, precuneus, and thalamus. Patients with abnormal MRI findings had worse APACHE II, SOFA, GOSE scores, increased prevalence of delirium and mortality. Presence of MRI lesions was associated with reduced C5a and iC3b levels and brain atrophy was associated with increased p-tau levels. Regression analysis identified an association between C5a levels and presence of lesion on MRI and p-tau levels and the presence of atrophy on MRI.

CONCLUSIONS

Neuronal loss predominantly occurs in limbic and visceral pain perception regions of SIBD patients. Complement breakdown products and p-tau stand out as adverse neuroimaging outcome markers for SIBD.

CD14+ Monocytic Cytokines: Impact on Outcome in Severely Injured Patients

Introduction:

Trauma is one of the leading causes of mortality worldwide. Trauma patients, who presented to the hospital casualty department within 24 h of injury, further admitted to the Surgical Intensive Care Unit were enrolled in this study.

Materials and Methods:

The aim was to study the peripheral blood monocyte activity to produce tumor necrosis factor (TNF-α), interleukin-1 (IL-1) β, IL-6, and IL-8 in severely injured patients after trauma.

Result:

A total of 28 polytrauma patients were enrolled and observed that the levels of TNF-α, IL-1 β, IL-6, and IL-8 were significantly decreased and levels of IL-8 were increased in the fatal patients compared to the healthy controls.

Conclusion:

After trauma, an immediate hyperactivation of circulating monocytes is rapidly followed by a substantial paralysis of cell function. Decreased activity of monocytes can be used to identify potential fatal immunological disruption. Since immunological disruption occurs before clinical symptoms; our study proposes an immunological prognostication score for trauma victims.

Prognostic value of postoperative complication for early recurrence after curative resection of hepatocellular carcinoma

BACKGROUND

Postoperative complications may adversely affect oncological outcomes. The aim of this study was to evaluate the impact of postoperative complications on early-phase recurrence after curative resection for hepatocellular carcinoma (HCC).

METHODS

We included 145 HCC patients who underwent initial and curative resection between January 2004 and December 2013. Postoperative complications of grade III or higher based on Clavien-Dindo classification were defined as clinically relevant postoperative complications. Recurrence within two years after hepatectomy was defined as early-phase recurrence.

RESULTS

Thirty-eight patients (26%) developed postoperative complications. The only predictive factor for postoperative complication was longer operative duration (P = 0.037). The disease-specific survival rate of patients with complication was lower than that of patients without complications (P = 0.015). Early-phase recurrence was observed in 20/38 (53%) patients who suffered postoperative complications and 36/107 (34%) patients with no complications, which was statistically significant (P = 0.039). Multivariate analysis identified four factors contributing to early-phase recurrence: high serum AFP level (P = 0.042), multiple tumors (P < 0.001), poor differentiation (P = 0.036) and presence of postoperative complication (P = 0.039).

CONCLUSIONS

Postoperative complication is an independent prognostic factor for early-phase recurrence after curative resection of HCC. Close observation of patients with postoperative complications may be a necessary treatment strategy for HCC.

Effects of propofol-based total intravenous anesthesia on gastric cancer: a retrospective study

Background

Several kinds of cancer surgeries with propofol-based total intravenous anesthesia (TIVA) have been shown to have better outcomes than those with sevoflurane-based inhalational anesthesia (INHA). However, the effects of this anesthetic technique have not been investigated in patients with gastric cancer. In this study, the authors retrospectively examined the link between the choice of anesthetic technique and overall survival in patients undergoing gastric cancer resection.

Methods

We conducted a retrospective analysis of the database of all patients undergoing gastric cancer resection for gastric cancer between 2007 and 2012. Patients who received TIVA or INHA were administered patient-controlled intravenous analgesia for 72-120 hours postoperatively. Survival was estimated using the Kaplan-Meier log-rank test, and associations between anesthetic technique and outcomes were analyzed using Cox proportional hazards regressions after propensity matching.

Results

A total of 2,856 anesthetics using INHA or TIVA were delivered in the study period. After propensity matching, 897 patients remained in each group. According to Kaplan-Meier analysis, the use of TIVA was associated with improved survival (P<0.001). TIVA was associated with a hazard ratio (HR) of 0.67 (95% confidence interval [CI]: 0.58-0.77) for death in univariate analysis and 0.65 (95% CI: 0.56-0.75) after a multivariate analysis of known confounders in the matched group. Cancer stage (HR =0.74, 95% CI: 0.64-0.86, P<0.001) and degree of differentiation (HR =1.28, 95% CI: 1.11-1.47, P<0.001) were also associated with survival in the univariate analysis in the matched group. In the multivariable Cox model, cancer stage (HR =0.72, 95% CI: 0.62-0.84, P<0.001) and degree of differentiation (HR =1.23, 95% CI: 1.07-1.42, P<0.001) were associated with survival in the matched group.

Conclusion

These results indicate that TIVA may be associated with improved survival in gastric cancer patients who undergo resection.

Traumatic Injury

Traumatic injury as one of the world's most relevant but neglected health concerns results in modulated inflammasome activity, which is closely linked to the development of post-injury complications. Cytokine-producing capacity of cells is important for the appropriate immune response to trauma and requires not only synthesis and transcription of inflammasome components but also their activation. Unfortunately, the precise role of inflammasome in trauma is still largely unknown. However, in the following chapter, we provide an overview on the best described inflammasomes in the various settings of trauma, introducing the recent findings on the up-to-date best described NLRP inflammasomes and underlying cytokines in the inflammatory response to trauma.

Hyporesponsiveness of natural killer cells and impaired inflammatory responses in critically ill patients

Background

To investigate natural killer (NK) cell activity, circulating cytokine level and peripheral blood mononuclear cell (PBMC) cytokine production status in critically ill patients.

Methods

Blood samples were collected <24 h after admission from 24 intensive care unit (ICU) patients and 24 age-, sex-, and body mass index (BMI)-matched healthy controls. Serum cytokine concentrations and cytokine production by PBMCs and lipopolysaccharide (LPS)-stimulated PBMCs were measured.

Results

The ICU group showed lower NK cell activity than the controls under all conditions and an absence of interferon (IFN)-γ. After adjusting for triglycerides, LDL- and HDL-cholesterol, and glucose, the ICU group exhibited lower serum levels of albumin and interleukin (IL)-12 and higher leukocyte counts and hs-CRP and IL-6 levels than the controls. Non-stimulated PBMCs from ICU patients secreted significantly greater amounts of IL-6 and IL-1β than the controls; however, the production of IL-6, TNF-α and IL-1β in response to LPS stimulation was significantly lower in the ICU group.

Conclusions

Significant reductions in NK cell activity and serum IL-12 level, an absence of serum IFN-γ, and decreased cytokine production from LPS-stimulated PBMCs indicate the hyporesponsiveness of NK cells and an impaired early phase inflammatory response in critically ill patients (ClinicalTrials.gov NCT02565589:). Retrospectively registered; October 1, 2015.

Defects in innate and adaptive immunity in patients with sepsis and health care associated infection

Recent advances in sepsis therapy exclusively involve improvements in supportive care, while sepsis mortality rates remain disturbingly high at 30%. These persistently high sepsis mortality rates arise from the absence of sepsis specific therapies. However with improvements in supportive care, patients with septic shock commonly partially recover from the infection that precipitated their initial illness, yet they frequently succumb to subsequent health care associated infections. Remarkably today the pathophysiology of sepsis in humans, a common disease in western society, remains largely a conundrum. Conventionally sepsis was regarded as primarily a disorder of inflammation. More recently the importance of immune compromise in the pathophysiology of sepsis and health care associated infection has now become more widely accepted. Accordingly a review of the human evidence for this novel sepsis paradigm is timely. Septic patients appear to exhibit a complex and long-lasting immune deficiency state, involving lymphocytes of both the innate and adaptive immune responses that have been linked with mortality and the occurrence of health care associated infection. Such is the pervasive nature of immune compromise in sepsis that ultimately immune modulation will play a crucial role in sepsis therapies of the future.

The Effect of Surgical Stress on Postoperative Tαβ and Tγδ Cell Distribution

BACKGROUND

It was previously shown that appropriate distribution of immune cells between different tissues and organs of the body is required for proper function of the immune system. Our previous experiments demonstrated that surgical trauma in mice induces Tγδ lymphocyte migration from peripheral blood to peritoneal lymphoid organs. Tγδ cells have regulatory activity as they suppress the cell-mediated immune response in vitro via TGF-β. In the current study, we aim to evaluate the influence of surgery on both Taβ and Tγδ lymphocyte distribution in patients that underwent operation.

MATERIALS AND METHODS

We investigated the percentage of Tαβ and Tγδ cells in peripheral blood of patients undergoing standard surgical procedures (gastric resection, colorectal resection, cholecystectomy, and strumectomy) before and 3 days after operation. The percentage of Tαβ and Tγδ cells was evaluated by FACS Canto II cytofluorimeter.

RESULTS

We showed that only major surgery located in the peritoneal cavity (gastric and colorectal surgery) decreases the percentage of Tγδ cells in peripheral blood as opposed to less traumatic surgery (strumectomy and cholecystectomy) which does not have such effect. However, significant reduction of Tγδ cells after operation was only observed in a group of patients that underwent gastrectomy. Additionally, we found that gastrectomy results in significant reduction of cumulative Tγδ CD4 and Tγδ CD25 lymphocyte counts.

CONCLUSION

Surgery results in decreased percentage of Tγδ lymphocytes in peripheral human blood, and this correlates with the severity and location of the surgical trauma. This observation may help to predict postoperative recovery after gastroabdominal surgery.

Persistent lymphopenia is a risk factor for ICU-acquired infections and for death in ICU patients with sustained hypotension at admission

Background

Severely ill patients might develop an alteration of their immune system called post-aggressive immunosuppression. We sought to assess the risk of ICU-acquired infection and of mortality according to the absolute lymphocyte count at ICU admission and its changes over 3 days.

Methods

Adults in ICU for at least 3 days with a shock or persistent low blood pressure were extracted from a French ICU database and included. We evaluated the impact of the absolute lymphocyte count at baseline and its change at day 3 on the incidence of ICU-acquired infection and on the 28-day mortality rate. We categorized lymphocytes in 4 groups: above 1.5 × 10³ cells/µL; between 1 and 1.5 × 10³ cells/µL; between 0.5 and 1 × 10³ cells/µL; and below 0.5 × 10³ cells/µL.

Results

A total of 753 patients were included. The median lymphocyte count was 0.8 × 10³ cells/µL [0.51–1.29]. A total of 174 (23%) patients developed infections; the 28-day mortality rate was 21% (161/753). Lymphopenia at admission was associated with ICU-acquired infection (p < 0.001) but not with 28-day mortality. Independently of baseline lymphocyte count, the absence of lymphocyte count increase at day 3 was associated with ICU-acquired infection (sub-distribution hazard ratio sHR: 1.37 [1.12–1.67], p = 0.002) and with 28-day mortality (sHR: 1.67 [1.37–2.03], p < 0.0001).

Conclusion

Lymphopenia at ICU admission and its persistence at day 3 were associated with an increased risk of ICU-acquired infection, while only persisting lymphopenia predicted increased 28-day mortality. The lymphocyte count at ICU admission and at day 3 could be used as a simple and reproductive marker of post-aggressive immunosuppression.

Electronic supplementary material

The online version of this article (doi:10.1186/s13613-017-0242-0) contains supplementary material, which is available to authorized users.

Impaired Surface Expression of HLA-DR, TLR2, TLR4, and TLR9 in Ex Vivo-In Vitro Stimulated Monocytes from Severely Injured Trauma Patients

Objective. Trauma patients (TP) frequently develop an imbalanced immune response that often causes infectious postinjury complications. Monocytes show a diminished capability of both producing proinflammatory cytokines and antigen presentation after trauma. TLR2, TLR4, and TLR9 recognize pathogens and subsequently activate monocytes. While there are conflictive data about TLR2 and TLR4 expression after trauma, no studies about the expression of TLR2, TLR4, TLR9, and HLA-DR on monocytes from TP after their secondary ex vivo-in vitro "hit" have been reported. Methods/Results. Ex vivo-in vitro lipopolysaccharide- (LPS-) stimulated blood from TP showed diminished interleukin- (IL-) 1β-release in TP for five postinjury days compared to healthy volunteers (HV). The recovery was observed at day 5. In parallel, monocytes from TP showed an impaired capability of TLR2, TLR4, and TLR9 expression after secondary stimulation compared to HV, while the measurement of unstimulated samples showed significant reduction of TLR4 and TLR9 at ED. Furthermore, HLA-DR decreased after trauma and was even more profound by stimulation of monocytes. Ratio of monocytes to leukocytes was significantly increased at days 6 and 7 after trauma compared to HV. Conclusion. Impaired expression of TLRs and HLA-DR in acute inflammatory conditions may be responsible for the well-described monocyte paralysis after severe trauma.

Interaction between ANXA1 and GATA-3 in Immunosuppression of CD4+ T Cells

Decreased Th1/Th2 ratio is one of the major characteristics of immunosuppression in sepsis. Both membrane adhesive protein Annexin-A1 (ANXA1) and transcription factor GATA-3 have been reported to play important roles in T cell differentiation. However, the relationship between ANXA1 and GATA-3 in Th1/Th2 shift is unknown. Our study investigated the interaction effects of ANXA1 and GATA-3 to influence T cell differentiation in CD4+ T cells. We found that GATA-3 and ANXA1 were coexpressed on Th0/Th1/Th2 cytoplasm and nuclear. Overexpressed ANXA1 significantly increased the expression of IFNγ and reduced IL-4 expression in T cells, while ANXA1-silenced T cells exhibited decreased production of IFNγ and increased production of IL-4. Knockdown of ANXA1 promoted higher expression level of GATA-3 and low level of T-box transcription factor (T-bet/Tbx21). Further study demonstrated that ANXA1 regulated GATA-3 expression through the formyl peptide receptor like-1 (FPRL-1) downstream signaling pathways ERK and PKB/Akt. These results suggested that ANXA1 modulates GATA-3/T-bet expression induced Th0/Th1 differentiation. Moreover, we found that GATA-3 inhibited ANXA1 expression by binding to its promoter for the first time. It is proposed that the interactions between ANXA1 and GATA-3 may provide clues to understand the immunosuppression and have potential as new therapeutic targets in immunotherapy after sepsis.

Regulation of Cellular Immune Responses in Sepsis by Histone Modifications

Severe sepsis, septic shock, and related inflammatory syndromes are driven by the aberrant expression of proinflammatory mediators by immune cells. During the acute phase of sepsis, overexpression of chemokines and cytokines drives physiological stress leading to organ failure and mortality. Following recovery from sepsis, the immune system exhibits profound immunosuppression, evidenced by an inability to produce the same proinflammatory mediators that are required for normal responses to infectious microorganisms. Gene expression in inflammatory responses is influenced by the transcriptional accessibility of the chromatin, with histone posttranslational modifications determining whether inflammatory gene loci are set to transcriptionally active, repressed, or poised states. Experimental evidence indicates that histone modifications play a central role in governing the cytokine storm of severe sepsis, and that aberrant chromatin modifications induced during the acute phase of sepsis may mediate chronic immunosuppression in sepsis survivors. This review will focus on the role of histone modifications in governing immune responses in severe sepsis, with an emphasis on specific leukocyte subsets and the histone modifications observed in these cells during chronic stages of sepsis. Additionally, the expression and function of chromatin-modifying enzymes (CMEs) will be discussed in the context of severe sepsis, as potential mediators of epigenetic regulation of gene expression in sepsis responses. In summary, this review will argue for the use of chromatin modifications and CME expression in leukocytes as potential biomarkers of immunosuppression in patients with severe sepsis.

Survival Determinants after Pancreatectomy With Vascular Resection for Pancreatic Cancer

To investigate the morbidity, mortality, and survival of patients with pancreatic cancer after pancreatectomy with vascular resection and to clarify the favorable prognostic survival factors. Pancreatic cancer is a malignant tumor. Many revisions have been made to surgical procedures to improve the prognosis of resectable pancreatic cancer. Several studies have compared no-vein and vein resection with pancreaticoduodenectomy, recording their feasibility and equal rates of operative mortality, incidence, and survival. Factors identified as potentially relevant to survival outcomes include population, perioperative treatment, and clinical pathologic factors, but these are still controversial. From January 1, 2003, to December 31, 2010, 63 patients with advanced pancreatic cancer underwent pancreatectomy with vascular resection. They were divided into 2 groups: one group had a survival time of &lt;2 years (group 1) and the other a survival time of &gt;2 years (group 2). Their clinical data, surgical techniques, perioperative parameters, and histopathologic data from a prospective database were analyzed. Major venous resection with reconstruction was performed in 61 patients (96.83%); major venous and artery resection with reconstruction in 1 patient (1.58%); and arterial resection with reconstruction in another patient (1.58%). The median survival time and the actuarial 1-, 2-, and 3-year survival rates for all patients are 19.94 months and 45.0%, 27.4%, and 17.6%, respectively. Group 1 contained 42 patients and group 2 contained 21 patients. A multivariate analysis identified tumor size, tumor differentiation, lymph-node status, nerve invasion, and metastasis (TNM) staging of the pancreatic cancer, tumor grade, operating time, and chemotherapy after surgery as independent predictors of long-term survival. TNM staging, tumor grade, operating time, and chemotherapy are independent predictors of survival after pancreatectomy.

Inflammatory Changes and Coagulopathy in Multiply Injured Patients

Severe tissue trauma leads to an early activation of several danger recognition systems, including the complement and the coagulation system, often resulting in an overwhelming almost synchronic pro- and anti-inflammatory response of the host. Although the immune response is associated with beneficial effects at the site of injury including the elimination of exogenous and endogenous danger molecules as well as the initiation of regenerative processes, an exaggerated systemic inflammatory response significantly contributes to posttraumatic complications such as multiple organ failure (MOF) and early death. Besides pre-existing physical conditions, age, gender, and underlying comorbidities, surgical and anesthesiological management after injury is decisive for outcome. Improvements in surgical intensive care have increased number of patients who survive the initial phase after trauma. However, instead of progressing to normal recovery, patients often pass into persistent inflammation, immunosuppression, and catabolism syndrome (PICS). The characterization and management of PICS will require new strategies for direct monitoring and therapeutic intervention into the patient’s immune function. In this chapter, we describe various factors involved in the inflammatory changes after trauma and aim to understand how these factors interact to progress to systemic inflammation, MOF, and PICS.

Postoperative complications affect early recurrence of hepatocellular carcinoma after curative resection

Background

Postoperative recurrence remains the major cause of death after curative resection for hepatocellular carcinoma (HCC). This study was conducted to evaluate the impact of postoperative complications on HCC recurrence after curative resection.

Methods

The postoperative outcomes of 274 HCC patients who underwent curative resection were analysed retrospectively.

Results

Of the 247 HCC patients, 103 (37.6 %) patients developed postoperative complications. The occurrence of postoperative complications was found to be associated with a significantly higher tumor recurrence (76.2 % vs. 56.6 %, P = 0.002) and a lower 5-year overall survival rate (27.7 % vs. 42.1 %; P = 0.037) as compared with those without complications. Regarding the recurrence pattern, early recurrence (≤2 years) was more frequently seen in patients with complications than that in patients without complications (54.5 % vs.38.6 %; P = 0.011). Multivariate analysis indicated that postoperative complications occurrence was an independent risk factor for early recurrence (odds ratio [OR] 2.223; 95 % confidence intervals [95 % CI] 1.161–4.258, P = 0.016) and poor overall survival (OR 1.413; 95 % CI, 1.012–1.971, P = 0.042).

Conclusions

The results of the present study indicate that the occurrence of postoperative complications is a predictive factor for HCC recurrence after curative hepatectomy, especially for early recurrence.

Role of IL-12 in overcoming the low responsiveness of NK cells to missing self after traumatic brain injury

Blood samples from 32 patients with severe Traumatic brain injury (TBI) were studied and compared with 11 cardiac surgery patients, and 29 healthy controls. A dramatic decreased expression of HLA class I molecules on monocytes was associated with increased KIR+ NK cell frequency in TBI patients. Overall, the phenotype of TBI NK cells marked by KIR and CD57 expression and lower level of NKp46 and DNAM-1 reflected a differentiated state. The NK-cell response to missing self was marked by lower degranulation and lower IFN-γ production after stimulation with HLA class I deficient cell line. In contrast, the NK-cell ADCC was not altered. IL-12 was able to restore both IFN-γ production and the cytotoxicity capacities of NK cells. This study provides the first extensive description of the phenotype and functions of NK cells in TBI patients. Further evaluation of IL-12 treatment to overcome immunosuppression-induced nosocomial infections is warranted.

Bone Components Downregulate Expression of Toll-Like Receptor 4 on the Surface of Human Monocytic U937 Cells: A Cell Model for Postfracture Immune Dysfunction

To mimic the immune status of monocyte in the localized fracture region, toll-like receptor 4 (TLR4) surface expression in human monocytic U937 cells was used as the main target to assess immune dysfunction following bone component exposure. We first identified the effects of bone components (including the marrow content) on TLR4 surface expression and then examined the mechanisms underlying the changes. The level of microRNA-146a expression, an indicator of endotoxin tolerance, was also assayed. Bone component exposure downregulated TLR4 surface expression at 24 h by flow cytometry analysis, compatible with the result obtained from the membranous portion of TLR4 by western blot analysis. The cytoplasmic portion of TLR4 paradoxically increased after bone component exposure. Impaired TLR4 trafficking from the cytoplasm to the membrane was related to gp96 downregulation, as observed by western blot analysis, and this was further evidenced by gp96-TLR4 colocalization under confocal microscopy. TaqMan analysis revealed that the expression of microRNA-146a was also upregulated. This cell model demonstrated that bone component exposure downregulated TLR4 surface expression in a gp96-related manner in human monocytic U937 cells, an indicator of immunosuppression at 24 h. Immune dysfunction was further evidenced by upregulation of microRNA-146a expression at the same time point.

Nlrp1 inflammasome is downregulated in trauma patients

After a major trauma, IL-1β-producing capacity of monocytes is reduced. Generation of IL-1β is important for appropriate immune response after trauma and requires not only synthesis and transcription of inflammasome components but also their activation. Altered IL-1β-processing due to deregulated NLRP inflammasomes assembly is associated with several inflammatory diseases. However, the precise role of NLRP1 inflammasome in monocytes after trauma is unknown. Here, we investigated if NLRP1 inflammasome components are responsible for depressed monocyte function after trauma. We found in ex vivo in vitro assays that LPS-stimulation of CD14(+)-isolated monocytes from healthy volunteers (HV) results in remarkably higher capacity of the IL-1β-release compared to trauma patients (TP). During the 10-day time course, this monocyte depression was highest immediately after admission. Inflammasome activation correlating with this inflammatory response was demonstrated by enhanced protein production of cleaved IL-1β and caspase-1. Furthermore, we found that the gene expression of IL-1β, caspase-1, and ASC was comparable in TP and HV after LPS-stimulation during the 10-day course, while NLRP1 was markedly reduced in TP. We demonstrated that transfected monocytes from TP, which expressed the lacking components, were recovered in their LPS-induced IL-1β-release and that lacking of NLRP1 is responsible for the suppressed monocyte activity after trauma. The restoration of NLRP1 inflammasome suggests new mechanistic target for the recovery of dysbalanced immune reaction after trauma.

KEY MESSAGE

Suppression in monocyte function occurs early after a major trauma or surgery. Reduced gene expression abrogates NLRP1 inflammasome assembly after trauma. Limited availability of inflammasome components may cause reduced host defense. Restoring NLRP1 in immune-suppressed monocytes recovers NLPR1 activity after trauma. Recovered inflammasome activity may improve the immune response to PAMPs/DAMPs.

Sepsis-induced immune alterations monitoring by flow cytometry as a promising tool for individualized therapy

Septic syndromes remain a major although largely under-recognized health care problem and represent the first cause of mortality in intensive care units. While sepsis has, for long, been solely described as inducing a tremendous systemic inflammatory response, novel findings indicate that sepsis indeed initiates a more complex immunologic response that varies over time, with the concomitant occurrence of both pro- and anti-inflammatory mechanisms. As a resultant, after a short proinflammatory phase, septic patients enter a stage of protracted immunosuppression. This is illustrated in those patients by reactivation of dormant viruses (CMV or HSV) or infections due to pathogens, including fungi, which are normally pathogenic solely in immunocompromised hosts. Although mechanisms are not totally understood, these alterations might be directly responsible for worsening outcome in patients who survived initial resuscitation as nearly all immune functions are deeply compromised. Indeed, the magnitude and persistence over time of these dysfunctions have been associated with increased mortality and health-care associated infection rate. Consequently, new promising therapeutic avenues are currently emerging from those recent findings such as adjunctive immunostimulation (IFN-γ, GM-CSF, IL-7, anti-PD1/L1 antibodies) for the most immunosuppressed patients. Nevertheless, as there is no clinical sign of immune dysfunctions, the prerequisite for such therapeutic intervention relies on our capacity in identifying the patients who could benefit from immunostimulation. To date, the most robust biomarkers of sepsis-induced immunosuppression are measured by flow cytometry. Of them, the decreased expression of monocyte HLA-DR appears as a "gold standard." This review reports on the mechanisms sustaining sepsis-induced immunosuppression and its related biomarkers measurable by flow cytometry. The objective is to integrate the most recent facts in an up-to-date account of clinical results, flow cytometry aspects as well as issues in results standardization for multicenter studies. © 2015 International Clinical Cytometry Society.

Invasive Surgery Impairs the Regulatory Function of Human CD56 bright Natural Killer Cells in Response to Staphylococcus aureus. Suppression of Interferon-γ Synthesis

Major surgery increases the risk for infectious complications due to the development of immunosuppression. CD56^bright NK cells play a key role in the defense against bacterial infections through the release of Interferon (IFN) γ upon stimulation with monocyte-derived Interleukin (IL) 12. We investigated whether invasive visceral surgery interferes with the IFN-γ synthesis of human NK cells in response to Staphylococcus aureus. In a prospective pilot study, peripheral blood mononuclear cells (PBMC) were isolated from 53 patients before and 1 to 7 d after elective visceral surgery. The release of IL-12 and IFN-γ from PBMC upon exposure to S. aureus in vitro was quantified. The expression of the IL-12 receptor β1 chain on the surface, the phosphorylation of signal transducer and activator of transcription (STAT) 4, and the synthesis of IFN-γ on/in individual CD56^bright NK cells were investigated using flow cytometry. The modulatory effect of IL-12 on the S. aureus-induced IFN-γ production in CD56^bright NK cells was analyzed. The IFN-γ secretion from purified CD56^bright NK cells was quantified after stimulation with IL-12 and IL-18. After surgery, CD56^bright NK cells among total PBMC were impaired in the release of IFN-γ for at least 5 d. Likewise, the IL-12-induced release of IFN-γ from purified CD56^bright NK cells was abolished. Upon stimulation with S. aureus, PBMC secreted less IL-12 but supplementation with recombinant IL-12 did not restore the capacity of CD56^bright NK cells to produce IFN-γ. CD56^bright NK cells displayed reduced levels of the IL-12Rβ1 chain whereas the phosphorylation of STAT4, the key transcription factor for the Ifng gene was not diminished. In summary, after invasive visceral surgery, CD56^bright NK cells are impaired in S. aureus-induced IFN-γ production and might contribute to the enhanced susceptibility to opportunistic infections.

Breaking the co-operation between bystander T-cells and natural killer cells prevents the development of immunosuppression after traumatic skeletal muscle injury in mice

Nosocomial infections represent serious complications after traumatic or surgical injuries in intensive care units. The pathogenesis of the underlying immunosuppression is only incompletely understood. In the present study, we investigated whether injury interferes with the function of the adaptive immune system in particular with the differentiation of antigen-specific T helper (Th)-cell responses in vivo. We used a mouse model for traumatic gastrocnemius muscle injury. Ovalbumin (OVA), which served as a foreign model antigen, was injected into the hind footpads for determination of the differentiation of OVA-specific Th-cells in the draining popliteal lymph node (pLN). The release of interferon (IFN)-γ from OVA-specific Th-cells was impaired within 24 h after injury and this impairment persisted for at least 7 days. In contrast, the proliferation of OVA-specific Th-cells remained unaffected. Injury did not modulate the function of antigen-presenting cells (APCs) in the pLN. Adoptive transfer of total T-cells from pLNs of injured mice inhibited IFN-γ production by OVA-specific Th-cells in naive mice. Suppressed Th1 priming did not occur in lymphocyte-deficient mice after injury but was restored by administration of T-cells before injury. Moreover, the suppression of Th1 differentiation required the presence of natural killer (NK) cells that were recruited to the pLN after injury; this recruitment was dependent on lymphocytes, toll-like receptor 4 (TLR4) and myeloid differentiation factor 88 (MyD88). In summary, upon traumatic skeletal muscle injury T-cells and NK cells together prevent the development of protective Th1 immunity. Breaking this co-operation might be a novel approach to reduce the risk of infectious complications after injury.

Depressed Monocytic Activity may be a Predictor for Sepsis

Introduction:

Trauma is one of the leading causes of mortality worldwide with infections as important causes of death in such patients. Bacterial infections cause activation of monocytes with excessive synthesis of pro-inflammatory cytokines. Hence, this prospective study was conducted to assess the activity of monocytes in traumatized sepsis patients using flow cytometry and to assess if they have any prognostic potential.

Materials and Methods:

A total of 16 consecutive trauma patients with sepsis and having positive blood culture were enrolled, along with four healthy controls during the period of March 2013 to July 2013. Blood from septic patients were collected on the same day when blood culture was positive and on days 2 and 5 thereafter. Surface staining for monocytes with CD14 and intracellular staining for interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-α) was done and results were analyzed by flow cytometer. Procalcitonin (PCT) assay was done using MiniVidas. Complete clinical follow-up was done for the patients.

Results:

Of the 16 patients, four died due to infections by various microorganisms. Isolated abdominal trauma (25%) was the most common injury among the enrolled patients of sepsis. Levels of TNF-α were significantly decreased when stimulated with lipopolysaccharide in the fatal patients as compared to the healthy controls. Patients having sepsis who survived had an increased level of TNF-α during the follow-up periods.

Conclusion:

This study showed that activity of monocytes to produce TNF-α and IL-6 were reduced in severe sepsis. Early identification of such immune-paralysis can help in earlier intervention to salvage this vulnerable trauma population.

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.

Changes in serum cytokines in response to musculoskeletal surgical trauma

Background

Trauma induces local and subsequent systemic inflammatory reactions, and when the cytokine production is deregulated, a systemic inflammatory response syndrome with a potentially lethal outcome can occur. The understanding of the physiological mechanism of the cytokine network would be useful to better comprehend pathological conditions.

Methods

We analysed a panel of 30 cytokines in the serum of 20 patients operated with total hip replacement. Cytokine release was assessed postoperatively up to 6 days by a multiplex antibody bead kit and compared to pre-operative values.

Results

Surgery induced significant increments in serum levels of IL-2R at 6 days after surgery, in levels of IL-6 at 6 hours after surgery and at 1 day after surgery, in levels of IL-8 at 6 hours after surgery, in levels of IL-16 at 6 hours and at 1 day after surgery. Significant decreases in serum levels of IL-1Rα were found at the end of surgery, in levels of IL-12 at the end of surgery and at 6 hours after, and in levels of Eotaxin during all phases of the postoperative course.

Conclusions

The major findings were significant increases in systemic levels of the pro-inflammatory cytokines IL-6, IL-8, IL-16, while IL-12 was significantly decreased. Otherwise there were modest changes in the systemic cytokine kinetics and no significant expression of anti-inflammatory cytokines.

Circulating monocytes are not the major source of plasma cytokines in patients with sepsis

In sepsis, large quantities of inflammatory cytokines are released into the bloodstream. The cellular source of these cytokines is unclear, and we have here investigated to what extent circulating cells in blood contributed to this production. We used the enzyme-linked immunospot technique to study the spontaneous as well as the lipopolysaccharide (LPS)-induced secretion of the proinflammatory cytokines interleukin 6 (IL-6), tumor necrosis factor α (TNF-α), granulocyte-macrophage colony-stimulating factor, IL-1β, IL-12p40, and the anti-inflammatory cytokine IL-10 from whole-blood cells. The study comprised 32 septic patients (24 with septic shock) and 30 healthy controls. Despite significantly increased plasma cytokine levels in the septic patients, the number of spontaneous cytokine-secreting cells was small or nonexistent and did not differ between the two groups. Lipopolysaccharide stimulation of cells from the same samples triggered substantially increased numbers of cytokine-producing cells in both patients and controls. However, although the numbers of IL-6- and tumor necrosis factor α-secreting monocytes were very similar in both groups, significantly fewer IL-1β-, IL-10-, IL-12p40-, and granulocyte-macrophage colony-stimulating factor-secreting monocytes were seen in samples from septic patients as compared with healthy controls. The reduced number of cytokine-secreting cells in response to LPS stimulation correlated with disease severity, as expressed by Sequential Organ Failure Assessment score and the stage of sepsis. In summary, circulating leukocytes did not appear to be responsible for the increased plasma levels of cytokines observed in sepsis. A selective sepsis-induced downregulation of cytokine secretion in response to LPS underscores the complexity of cytokine regulation in sepsis.

Lymphocyte modulation with FTY720 improves hemorrhagic shock survival in swine

The inflammatory response to severe traumatic injury results in significant morbidity and mortality. Lymphocytes have recently been identified as critical mediators of the early innate immune response to ischemia-reperfusion injury. Experimental manipulation of lymphocytes following hemorrhagic shock may prevent secondary immunologic injury in surgical and trauma patients. The objective of this study is to evaluate the lymphocyte sequestration agent FTY720 as an immunomodulator following experimental hemorrhagic shock in a swine liver injury model. Yorkshire swine were anesthetized and underwent a grade III liver injury with uncontrolled hemorrhage to induce hemorrhagic shock. Experimental groups were treated with a lymphocyte sequestration agent, FTY720, (n = 9) and compared to a vehicle control group (n = 9). Animals were observed over a 3 day survival period after hemorrhage. Circulating total leukocyte and neutrophil counts were measured. Central lymphocytes were evaluated with mesenteric lymph node and spleen immunohistochemistry (IHC) staining for CD3. Lung tissue infiltrating neutrophils were analyzed with myeloperoxidase (MPO) IHC staining. Relevant immune-related gene expression from liver tissue was quantified using RT-PCR. The overall survival was 22.2% in the vehicle control and 66.7% in the FTY720 groups (p = 0.081), and reperfusion survival (period after hemorrhage) was 25% in the vehicle control and 75% in the FTY720 groups (p = 0.047). CD3⁺ lymphocytes were significantly increased in mesenteric lymph nodes and spleen in the FTY720 group compared to vehicle control, indicating central lymphocyte sequestration. Lymphocyte disruption significantly decreased circulating and lung tissue infiltrating neutrophils, and decreased expression of liver immune-related gene expression in the FTY720 treated group. There were no observed infectious or wound healing complications. Lymphocyte sequestration with FTY720 improves survival in experimental hemorrhagic shock using a porcine liver injury model. These results support a novel and clinically relevant lymphocyte immunomodulation strategy to ameliorate secondary immune injury in hemorrhagic shock.

Complement takes its Toll: an inflammatory crosstalk between Toll-like receptors and the receptors for the complement anaphylatoxin C5a

The innate immune system is responsible for a rapid inflammatory response to pathogens that is essential for the clearance of infections. Although this response is vital, it is nonetheless potentially harmful, and dysregulated inflammation is a feature of many disease states. Thus, the mechanisms that regulate the release of soluble mediators of inflammation are an active focus of investigation. The activation by infections of two key components of the innate immune system, the Toll-like receptors (TLRs) and complement, leading to the release of soluble mediators of inflammation, is critical to microbial killing and clearance. Both TLRs and complement are independently capable of triggering pro-inflammatory responses, but their synergistic interaction resulting from a substantial crosstalk markedly amplifies those responses and may contribute to the pathophysiology of diseases such as sepsis.

Association between infection early in life and mental disorders among youth in the community: a cross-sectional study

BACKGROUND

The objective of this study was to examine the association between infection early in life and mental disorders among youth in the community.

METHODS

Data were drawn from the MECA (Methods in Epidemiology of Child and Adolescent psychopathology), a community-based study of 1,285 youth in the United States conducted in 1992. Multiple logistic regression analyses were used to investigate the association between parent/caregiver-reported infection early in life and DSM/DISC diagnoses of mental disorders at ages 9-17.

RESULTS

Infection early in life was associated with a significantly increased odds of major depression (OR = 3.9), social phobia (OR = 5.8), overanxious disorder (OR = 6.1), panic disorder (OR = 12.1), and oppositional defiant disorder (OR = 3.7).

CONCLUSIONS

These findings are consistent with and extend previous results by providing new evidence suggesting a link between infection early in life and increased risk of depression and anxiety disorders among youth. These results should be considered preliminary. Replication of these findings with longitudinal epidemiologic data is needed. Possible mechanisms are discussed.

Dysregulated cytokine expression by CD4+ T cells from post-septic mice modulates both Th1 and Th2-mediated granulomatous lung inflammation

Previous epidemiological studies in humans and experimental studies in animals indicate that survivors of severe sepsis exhibit deficiencies in the activation and effector function of immune cells. In particular, CD4+ T lymphocytes can exhibit reduced proliferative capacity and improper cytokine responses following sepsis. To further investigate the cell-intrinsic defects of CD4+ T cells following sepsis, splenic CD4+ T cells from sham surgery and post-septic mice were transferred into lymphopenic mice. These recipient mice were then subjected to both TH1-(purified protein derivative) and TH2-(Schistosoma mansoni egg antigen) driven models of granulomatous lung inflammation. Post-septic CD4+ T cells mediated smaller TH1 and larger TH2 lung granulomas as compared to mice receiving CD4+ T cells from sham surgery donors. However, cytokine production by lymph node cells in antigen restimulation assays indicated increased pan-specific cytokine expression by post-septic CD4+ T cell recipient mice in both TH1 and TH2 granuloma models. These include increased production of T_H2 cytokines in TH1 inflammation, and increased production of T_H1 cytokines in TH2 inflammation. These results suggest that cell-intrinsic defects in CD4+ T cell effector function can have deleterious effects on inflammatory processes post-sepsis, due to a defect in the proper regulation of TH-specific cytokine expression.

Burn injury suppresses human dermal dendritic cell and Langerhans cell function

Human skin contains epidermal Langerhans cells (LCs) and dermal dendritic cells (DCs) that are key players in induction of adaptive immunity upon infection. After major burn injury, suppressed adaptive immunity has been observed in patients. Here we demonstrate that burn injury affects adaptive immunity by altering both epidermal LC and dermal DC functions. We developed a human ex vivo burn injury model to study the function of DCs in thermally injured skin. No differences were observed in the capacity of both LCs and dermal DCs to migrate out of burned skin compared to unburned skin. Similarly, expression levels of co-stimulatory molecules were unaltered. Notably, we observed a strong reduction of T cell activation induced by antigen presenting cell (APC) subsets that migrated from burned skin through soluble burn factors. Further analyses demonstrated that both epidermal LCs and dermal DCs have a decreased T cell stimulatory capacity after burn injury. Restoring the T cell stimulatory capacity of DC subsets might improve tissue regeneration in patients with burn wounds.

Ethanol changes gene expression of transcription factors and cytokine production of CD4+ T-cell subsets in PBMCs stimulated with LPS

BACKGROUND

Acute ethanol intoxication has the potential to alter immune reactivity by various pathways. The aim of this study was to investigate T-helper cell subsets transcription factors and cytokines in human peripheral blood mononuclear cells (PBMCs) following a single dose of lipopolysaccharide (LPS) with or without ethanol exposure.

METHODS

Human PBMCs were cultured in the presence of 100 mM ethanol and/or 100 ng/ml LPS for various time periods (1, 3, 8, and 24 hours) and analyzed for the kinetics of gene expression by quantitative real-time PCR of selected transcription factors (T-bet, GATA3, Foxp3, and RORγt) and cytokines (TNF-α, IL-6, IL-10, and IFN-γ). The proportion of Th17 and Treg cells was identified 24 hours after treatment with ethanol and LPS by multiparameter flow cytometry. Viability and amount of dead cells were analyzed after 24 and 48 hours by MTT assay and flow cytometry.

RESULTS

  Following LPS challenge, gene expression of Foxp3 increased, whereas RORγt decreased after 3 hours, GATA3 decreased within 1 hour, whereas expression of T-bet did not change at any time. Gene expression of TNF-α, interferon-γ (IFN-γ), and IL-6 peaked after 3 hours, expression of IL-10 peaked after 8 hours. Ethanol suppressed the LPS-induced gene expression of Foxp3, RORγt, and T-bet after 8 hours, expression of TNF-α and IFN-γ was also suppressed after 3 and 8 hours. Markers of inflammation including TNF-α and IL-1β in supernatant of PBMCs were significantly decreased, while levels of IL-10 and IL-6 remained unchanged following ethanol exposure. Furthermore, ethanol-treated cells alone or in combination with LPS had significantly fewer IL-17- and IFN-γ-secreting CD4+ T cells but constant proportion of Treg cells when compared to control cells. Proliferation and viability of the cells were not influenced under these conditions.

CONCLUSIONS

Alcohol interferes with the kinetics of Foxp3, RORγt, and T-bet gene expression and the production of TNF-α and IL-1ß and influences the balance of Treg/Th17 cells following LPS exposure.

CpG-ODN and MPLA prevent mortality in a murine model of post-hemorrhage-Staphyloccocus aureus pneumonia

Infections are the most frequent cause of complications in trauma patients. Post-traumatic immune suppression (IS) exposes patients to pneumonia (PN). The main pathogen involved in PN is Methicillin Susceptible Staphylococcus aureus (MSSA). Dendritic cells () may be centrally involved in the IS. We assessed the consequences of hemorrhage on pneumonia outcomes and investigated its consequences on DCs functions. A murine model of hemorrhagic shock with a subsequent MSSA pneumonia was used. Hemorrhage decreased the survival rate of infected mice, increased systemic dissemination of sepsis and worsened inflammatory lung lesions. The mRNA expression of Tumor Necrosis Factor-alpha (TNF-α), Interferon-beta (IFN-β) and Interleukin (IL)-12p40 were mitigated for hemorrhaged-mice. The effects of hemorrhage on subsequent PN were apparent on the pDCs phenotype (reduced MHC class II, CD80, and CD86 molecule membrane expression). In addition, hemorrhage dramatically decreased CD8⁺ cDCs- and CD8^- cDCs-induced allogeneic T-cell proliferation during PN compared with mice that did not undergo hemorrhage. In conclusion, hemorrhage increased morbidity and mortality associated with PN; induced severe phenotypic disturbances of the pDCs subset and functional alterations of the cDCs subset. After hemorrhage, a preventive treatment with CpG-ODN or Monophosphoryl Lipid A increased transcriptional activity in DCs (TNF-α, IFN-β and IL-12p40) and decreased mortality of post-hemorrhage MSSA pneumonia.

Immunosuppression following surgical and traumatic injury

Severe sepsis and organ failure are still the major causes of postoperative morbidity and mortality after major hepatobiliary pancreatic surgery. Despite recent progress in understanding the immune conditions of abdominal sepsis, the postoperative incidence of septic complications after major visceral surgery remains high. This review focuses on the clinical and immunological parameters that determine the risk of the development and lethal outcome of postoperative septic complication following major surgery and trauma. A review of the literature indicates that surgical and traumatic injury profoundly affects the innate and adaptive immune responses, and that a marked suppression in cell-mediated immunity following an excessive inflammatory response appears to be responsible for the increased susceptibility to subsequent sepsis. The innate and adaptive immune responses are initiated and modulated by pathogen-associated molecular-pattern molecules and by damage-associated molecular-pattern molecules through the pattern-recognition receptors. Suppression of cell-mediated immunity may be caused by multifaceted cytokine/inhibitor profiles in the circulation and other compartments of the host, excessive activation and dysregulated recruitment of polymorphonuclear neutrophils, induction of alternatively activated or regulatory macrophages that have anti-inflammatory properties, a shift in the T-helper (Th)1/Th2 balance toward Th2, appearance of regulatory T cells, which are potent suppressors of the innate and adaptive immune system, and lymphocyte apoptosis in patients with sepsis. Recent basic and clinical studies have elucidated the functional effects of surgical and traumatic injury on the immune system. The research studies of interest may in future aid in the selection of appropriate therapeutic protocols.

Early infection during burn-induced inflammatory response results in increased mortality and p38-mediated neutrophil dysfunction

Following burn injury, the host is susceptible to bacterial infections normally cleared by healthy patients. We hypothesized that during the systemic immune response that follows scald injury, the host's altered immune status increases infection susceptibility. Using a murine model of scald injury under inhaled anesthesia followed by intraperitoneal infection, we observed increased neutrophil numbers and function at postburn day (PBD) 1 compared with sham-burned and PBD4 mice. Further, increased mortality, bacteremia, and serum IL-6 were observed in PBD1 mice after Pseudomonas aeruginosa (PA) infection compared with sham-burned and PBD4 mice infected with PA. To examine these disparate responses, we investigated neutrophils isolated at 5 and 24 h following PA infection from PBD1 and sham-burned mice. Five hours after infection, there was no significant difference in number of recruited neutrophils; however, neutrophils from injured mice had decreased activation, active-p38, and oxidative burst compared with sham-burned mice. In direct contrast, 24 h after infection, we observed increased numbers, active-p38, and oxidative burst of neutrophils from PBD1 mice. Finally, we demonstrated that in neutrophils isolated from PBD1 mice, the observed increase in oxidative burst was p38 dependent. Altogether, neutrophil activation and function from thermally injured mice are initially delayed and later exacerbated by a p38-dependent mechanism. This mechanism is likely key to the observed increase in bacterial load and mortality of PBD1 mice infected with PA.