Serial increase of IL-12 response and human leukocyte antigen-DR expression in severe sepsis survivors

Prognostic value of inflammatory cytokine detection for sepsis patients in ICU: a meta-analysis

OBJECTIVE

To explore the prognostic effect of cytokine levels such as IL-6 (interleukin), IL-8 and TNF (tumor necrosis factor)-α on patients with sepsis in intensive care units (ICUs) by Meta-analysis.

METHODS

We systematically searched PubMed, Embase, Web of Science, Cochrane Library, China National Knowledge Infrastructure (CNKI), Wanfang, and other databases up to May 2023 to retrieve clinical research articles on cytokine testing for predicting sepsis prognosis in ICU settings. Relevant indicators were extracted and recorded in Excel. Meta-analyses were performed using RevMan 5.3.

RESULTS

A total of 25 studies were finally included in this Meta-analysis: 21 investigated IL-6, 6 examined IL-8, 11 addressed IL-10, 12 reviewed TNF-α, and 6 focused on IL-1β. Meta-analysis results demonstrated that cytokine levels (IL-6, IL-8, IL-10, TNF-α and IL-1β) in survival groups were substantially lower than those in non-survival groups (ALL P < 0.00001). Specific findings include significant differences in IL-6 [SMD = -25.32, 95% CI (-27.14, -23.49), P < 0.00001], IL-8 [SMD = -140.48, 95% CI (-154.32, -126.64), P < 0.00001], IL-10 [SMD = -54.10, 95% CI (-56.74, -51.47), P < 0.00001], TNF-α [SMD = -8.67, 95% CI (-9.82, -7.52), P < 0.00001], and IL-1β [SMD = -3.71, 95% CI (-4.11, -3.30), P < 0.00001]. The funnel plots for IL-6, IL-8, IL-10, TNF-α, and IL-1β displayed roughly symmetrical distributions, suggesting minimal bias and high reliability of the findings.

CONCLUSION

Cytokine levels such as IL-6, IL-8, and TNF-α are valuable prognostic indicators for patients with sepsis in the ICUs. Early testing of these cytokines can guide clinical interventions and enable targeted treatments for high-risk patients to reduce the likelihood of adverse outcomes.

Predictive value of CD86 for the occurrence of sepsis (Sepsis-3) in patients with infection

This prospective observational study explored the predictive value of CD86 in the early diagnosis of sepsis in the emergency department. The primary endpoint was the factors associated with a diagnosis of sepsis. The secondary endpoint was the factors associated with mortality among patients with sepsis. It enrolled inpatients with infection or high clinical suspicion of infection in the emergency department of a tertiary Hospital between September 2019 and June 2021. The patients were divided into the sepsis and non-sepsis groups according to the Sepsis-3 standard. The non-sepsis group included 56 patients, and the sepsis group included 65 patients (19 of whom ultimately died). The multivariable analysis showed that CD86% (odds ratio [OR] = 1.22, 95% confidence interval [CI]: 1.04-1.44, P = 0.015), platelet count (OR = 0.99, 95%CI: 0.986-0.997, P = 0.001), interleukin-10 (OR = 1.01, 95%CI: 1.004-1.025, P = 0.009), and procalcitonin (OR = 1.17, 95%CI: 1.01-1.37, P = 0.043) were independent risk factors for sepsis, while human leukocyte antigen (HLA%) (OR = 0.96, 05%CI: 0.935-0.995, P = 0.022), respiratory rate (OR = 1.16, 95%CI: 1.03-1.30, P = 0.014), and platelet count (OR = 1.01, 95%CI: 1.002-1.016, P = 0.016) were independent risk factors for death in patients with sepsis. The model for sepsis (CD86%, platelets, interleukin-10, and procalcitonin) and the model for death (HLA%, respiratory rate, and platelets) had an area under the curve (AUC) of 0.870 and 0.843, respectively. CD86% in the first 24 h after admission for acute infection was independently associated with the occurrence of sepsis in the emergency department.

Low monocytic HLA-DR expression in critically ill patients of sepsis: An indicator for antimicrobial and/or immunomodulatory intervention

BACKGROUND

Sepsis is a result of suppressed host immune response which leads to fatal multi-organ dysfunctionality. Low frequency of active monocytes or reduced expression of human leukocyte antigen (HLA)-DR on monocytes shows the suppressed immune response in sepsis patients. One of the well-studied markers in patients with sepsis is procalcitonin (PCT). The role of monocytic (m) HLA-DR expression has been monitored in sepsis and is being considered a marker of the severity of interim immuno-depression in these patients. The study describes the impact of HLA-DR expression on monocytes quantitatively using flow cytometry.

METHODS

In this prospective study, we quantified monocytes and their HLA-DR expression in 20 patients of sepsis admitted to the Intensive Care Unit (ICU). Serum levels of PCT and interleukin (IL)-6 production were also measured in these patients, and the results were compared with those in healthy controls.

RESULTS

Monocyte frequency calculated was higher in sepsis patients as compared to healthy controls, however, HLA-DR expressing monocytes were significantly reduced as was the mean fluorescence intensity (MFI) of HLA-DR. Contrastingly, IL-6 and PCT levels were significantly high in sepsis than controls. The results suggest that low HLA-DR expression, combined with PCT, is a better prognostic parameter in the early phase of sepsis.

CONCLUSION

Poor recovery of mHLA-DR may serve as an early guide for clinicians to assess the prognosis of sepsis patients and consider immunomodulatory therapy in its management.

Alterations in levels of cytokine following treatment to predict outcome of sepsis: A meta-analysis

BACKGROUND

The mortality rate of patients with sepsis has been increasing in recent years. Alterations of biomarkers levels during treatment are important in evaluating treatment efficacy and predicting outcomes in sepsis. This meta-analysis investigated the relationship between changes in cytokine levels after treatment compared with those on hospital admission, and their relationship with the prognosis of patients with sepsis.

METHODS

From conception until August 4, 2021, a complete literature search of the PubMed, Web of Science, and Cochrane Library electronic databases was done. Observational studies where the outcomes of sepsis patients were divided into non-survivors and survivors and which reported cytokine levels at least before treatment in ICU were included in the current study. Standardized mean difference (SMD) with 95% confidence intervals (CI) values from individual studies were pooled using a random-effects model. Quality assessment, subgroup analysis, publication bias, and sensitivity analyses were all carried out.

RESULTS

A total of 2570 patients with sepsis from 25 eligible studies were included, and 14 of them measured the cytokine levels before and after treatment in ICU. Among IL-6, TNF-α, IL-1β and IL-10 levels, those of IL-6 were significantly lower after treatment in ICU than at baseline in patients with sepsis in the survival group (SMD = -0.69, P < 0.0001), but were comparable in the non-survival group (SMD = -0.99, P = 0.0575). Similarly, post-treatment TNF-α levels were significantly lower than those at baseline only in patients with sepsis in the survival group (SMD = -0.44, P < 0.0001), but not in the non-survival group (SMD =-0.17, P = 0.0842).

CONCLUSION

This meta-analysis shows that reduced IL-6 and TNF-α levels after sepsis treatment in ICU may be indicators of better prognosis and survival of patients with sepsis.

Serial Increases in Human Leukocyte Antigen-DR Expression and Decreases in Interleukin-10 Expression in Alveolar Monocytes of Survivors of Pneumonia-Related Acute Respiratory Distress Syndrome

ARDS is a potentially lethal syndrome. HLA-DR expression in monocytes reflects their activation and antigen-presenting capacity. However, the correlation between clinical outcomes and HLA-DR expression in alveolar monocytes/macrophages in patients with pneumonia-related ARDS remains unclear. Thus, we determined the trends of HLA-DR and cytokine expressions in alveolar monocytes using repeated measurements to answer this question. Thirty-one pneumonia patients with respiratory failure and ARDS without coronavirus disease 2019 between November 2019 and November 2021 were enrolled in our intensive care unit and three without complete data were excluded. Interleukin (IL)-10, IL-12, and HLA-DR expression in bronchoalveolar lavage (BAL) monocytes were determined on days one and eight. Monocyte HLA-DR expression (mHLA-DR) and CD4 T lymphocytes percentages in BAL cells of survivors increased remarkably after seven days. Monocyte IL-10 expression and monocytes percentages in BAL cells of survivors decreased substantially after seven days. The mHLA-DR was negatively correlated with disease severity scores on day one and eight. In conclusion, serial increases in HLA-DR expression and decreases in IL-10 expression were observed in BAL monocytes of survivors of pneumonia-related ARDS. More studies are needed to confirm this point of view, and then development of a therapeutic agent restoring mHLA-DR and preventing IL-10 production can be considered.

Decreased Monocyte HLA-DR Expression in Patients with Sepsis and Acute Kidney Injury

Background and objectives: Acute kidney injury (AKI) is common in critically ill patients, especially those with sepsis. Persistently low human leukocyte antigen (HLA)-DR expression in monocytes reflects the decreased function of antigen-presenting cells, contributing to poor outcomes in sepsis. This study aimed to establish an association between AKI and HLA-DR expression in monocytes of patients with sepsis. Materials and Methods: We detected HLA-DR expression in monocytes and measured plasma levels of S100A12, high-mobility group box 1 (HMGB1), advanced glycation end products (AGE), and soluble receptor for AGE (sRAGE) from septic patients and healthy controls. Results: HLA-DR expression in monocytes was decreased in patients with AKI than in those without AKI (29.8 ± 5.0% vs. 53.1 ± 5.8%, p = 0.005). Compared with AKI patients, the mean monocyte HLA-DR expression in patients with end-stage renal disease was increased without statistical significance. There were no differences in the AGE/sRAGE ratio and plasma levels of S100A12, HMGB1, AGE, and sRAGE between patients with and without AKI. Conclusions: Compared with septic patients without AKI, patients with AKI had significantly lower HLA-DR expression in monocytes. The role of hemodialysis in monocyte HLA-DR expression needs further studies to explore.

Kynurenine Pathway-An Underestimated Factor Modulating Innate Immunity in Sepsis-Induced Acute Kidney Injury?

Sepsis is a life-threatening organ dysfunction caused by a dysregulated host response to infection, and it accounts for about half of the cases of acute kidney injury (AKI). Although sepsis is the most frequent cause of AKI in critically ill patients, its pathophysiological mechanisms are not well understood. Sepsis has the ability to modulate the function of cells belonging to the innate immune system. Increased activity of indoleamine 2,3-dioxygenase 1 (IDO1) and production of kynurenines are the major metabolic pathways utilized by innate immunity cells to maintain immunological tolerance. The activation of the kynurenine pathway (KP) plays a dual role in sepsis—in the early stage, the induction of IDO1 elicits strong proinflammatory effects that may lead to tissue damage and septic shock. Afterwards, depletion of tryptophan and production of kynurenines contribute to the development of immunosuppression that may cause the inability to overpower opportunistic infections. The presented review provides available data on the various interdependencies between elements of innate immunity and sepsis-induced AKI (SAKI) with particular emphasis on the immunomodulatory significance of KP in the above processes. We believe that KP activation may be one of the crucial, though underestimated, components of a deregulated host response to infection during SAKI.

Increased Production of Interleukin-10 and Tumor Necrosis Factor-Alpha in Stimulated Peripheral Blood Mononuclear Cells after Inhibition of S100A12

Sepsis may induce immunosuppression and result in death. S100A12 can bind to the receptor for advanced glycation end-products (RAGE) and Toll-like receptor (TLR)4 following induction of various inflammatory responses. It is unclear whether S100A12 significantly influences the immune system, which may be associated with sepsis-related mortality. We measured plasma S100A12 levels and cytokine responses (mean ± standard error mean) of lipopolysaccharide (LPS)-stimulated peripheral blood mononuclear cells (PBMCs) after S100A12 inhibition in healthy controls and patients with sepsis on days one and seven. Day one plasma soluble RAGE (sRAGE) and S100A12 levels in patients with sepsis were significantly higher than those in controls (2481.3 ± 295.0 vs. 1273.0 ± 108.2 pg/mL, p < 0.001; 530.3 ± 18.2 vs. 310.1 ± 28.1 pg/mL, p < 0.001, respectively). Day seven plasma S100A12 levels in non-survivors were significantly higher than those in survivors (593.1 ± 12.7 vs. 499.3 ± 23.8 pg/mL, p = 0.002, respectively). In survivors, plasma sRAGE levels were significantly decreased after 6 days (2297.3 ± 320.3 vs. 1530.1 ± 219.1 pg/mL, p = 0.009, respectively), but not in non-survivors. Inhibiting S100A12 increased the production of tumor necrosis factor (TNF)-α and interleukin (IL)-10 in stimulated PBMCs for both controls and patients. Therefore, S100A12 plays an important role in sepsis pathogenesis. S100A12 may competitively bind to TLR4 and RAGE, resulting in decreased IL-10 and TNF-α production.

Co-varying neighborhood analysis identifies cell populations associated with phenotypes of interest from single-cell transcriptomics

As single-cell datasets grow in sample size, there is a critical need to characterize cell states that vary across samples and associate with sample attributes, such as clinical phenotypes. Current statistical approaches typically map cells to clusters and then assess differences in cluster abundance. Here we present co-varying neighborhood analysis (CNA), an unbiased method to identify associated cell populations with greater flexibility than cluster-based approaches. CNA characterizes dominant axes of variation across samples by identifying groups of small regions in transcriptional space-termed neighborhoods-that co-vary in abundance across samples, suggesting shared function or regulation. CNA performs statistical testing for associations between any sample-level attribute and the abundances of these co-varying neighborhood groups. Simulations show that CNA enables more sensitive and accurate identification of disease-associated cell states than a cluster-based approach. When applied to published datasets, CNA captures a Notch activation signature in rheumatoid arthritis, identifies monocyte populations expanded in sepsis and identifies a novel T cell population associated with progression to active tuberculosis.

Functional Ex Vivo Testing of Alveolar Monocytes in Patients with Pneumonia-Related ARDS

Biomarkers of disease severity might help with individualizing the management of patients with acute respiratory distress syndrome (ARDS). During sepsis, a sustained decreased expression of the antigen-presenting molecule human leucocyte antigen-DR (HLA-DR) on circulating monocytes is used as a surrogate marker of immune failure. This study aimed at assessing whether HLA-DR expression on alveolar monocytes in the setting of a severe lung infection is associated with their functional alterations. BAL fluid and blood from immunocompetent patients with pneumonia-related ARDS admitted between 2016 and 2018 were isolated in a prospective monocentric study. Alveolar and blood monocytes were immunophenotyped using flow cytometry. Functional tests were performed on alveolar and blood monocytes after in vitro lipopolysaccharide (LPS) stimulation. Phagocytosis activity and intracellular tumor necrosis factor (TNF) production were quantified using fluorochrome-conjugated-specific antibodies. Ten ARDS and seven non-ARDS control patients were included. Patients with pneumonia-related ARDS exhibited significantly lower HLA-DR expression both on circulating (p < 0.0001) and alveolar (p = 0.0002) monocytes. There was no statistically significant difference observed between patient groups (ARDS vs. non-ARDS) regarding both alveolar and blood monocytes phagocytosis activity. After LPS stimulation, alveolar (p = 0.027) and blood (p = 0.005) monocytes from pneumonia-related ARDS patients had a significantly lower intracellular TNF expression than non-ARDS patients. Monocytes from pneumonia-related ARDS patients have a deactivated status and an impaired TNF production capacity but display potent phagocytic activity. HLA-DR level expression should not be used as a surrogate marker of the phagocytic activity or the TNF production capacity of alveolar monocytes.

PMMA-Based Continuous Hemofiltration Modulated Complement Activation and Renal Dysfunction in LPS-Induced Acute Kidney Injury

Sepsis-induced acute kidney injury (AKI) is a frequent complication in critically ill patients, refractory to conventional treatments. Aberrant activation of innate immune system may affect organ damage with poor prognosis for septic patients. Here, we investigated the efficacy of polymethyl methacrylate membrane (PMMA)-based continuous hemofiltration (CVVH) in modulating systemic and tissue immune activation in a swine model of LPS-induced AKI. After 3 h from LPS infusion, animals underwent to PMMA-CVVH or polysulfone (PS)-CVVH. Renal deposition of terminal complement mediator C5b-9 and of Pentraxin-3 (PTX3) deposits were evaluated on biopsies whereas systemic Complement activation was assessed by ELISA assay. Gene expression profile was performed from isolated peripheral blood mononuclear cells (PBMC) by microarrays and the results validated by Real-time PCR. Endotoxemic pigs presented oliguric AKI with increased tubulo-interstitial infiltrate, extensive collagen deposition, and glomerular thrombi; local PTX-3 and C5b-9 renal deposits and increased serum activation of classical and alternative Complement pathways were found in endotoxemic animals. PMMA-CVVH treatment significantly reduced tissue and systemic Complement activation limiting renal damage and fibrosis. By microarray analysis, we identified 711 and 913 differentially expressed genes with a fold change >2 and a false discovery rate <0.05 in endotoxemic pigs and PMMA-CVVH treated-animals, respectively. The most modulated genes were Granzyme B, Complement Factor B, Complement Component 4 Binding Protein Alpha, IL-12, and SERPINB-1 that were closely related to sepsis-induced immunological process. Our data suggest that PMMA-based CVVH can efficiently modulate immunological dysfunction in LPS-induced AKI.

lncRNA SNHG14 Plays a Role in Sepsis-Induced Acute Kidney Injury by Regulating miR-93

Acute kidney injury (AKI) is a common organ injury in sepsis, which leads to poor prognosis. Long noncoding RNA (lncRNA) small nucleolus RNA host gene 14 (SNHG14) was recognized to induce cell injury in LPS-induced acute lung injury and Parkinson's disease. We want to investigate the functions and mechanisms of SNHG14 in sepsis-induced AKI. Increased expression of SNHG14 was observed in LPS-induced HK-2 cells, and this was due to the activation of the TLR4/NF-κB pathway. In vitro studies showed that SNHG14 was involved in the oxidative stress, inflammation, and apoptosis of LPS-induced HK-2 cells. Further investigations confirmed that SNHG14 exerted the functions via miR-93 which could regulate the activation of NF-κB and STAT3 signaling by targeting IRAK4 and IL-6R. We also found that silencing SNHG14 also alleviated cellular injury processes of IL-1β and IL-6 in HK-2 cells via miR-93. We demonstrate that SNHG14 accelerates cellular injury in sepsis-induced AKI by activating IRAK4/NF-κB and IL-6R/STAT3 signaling via miR-93.

The role of NK cells in fighting the virus infection and sepsis

Natural killer cells, one of the important types of innate immune cells, play a pivotal role in the antiviral process in vivo. It has been shown that increasing NK cell activity may promote the alleviation of viral infections, even severe infection-induced sepsis. Given the current state of the novel coronavirus (SARS-CoV-2) global pandemic, clarifying the anti-viral function of NK cells would be helpful for revealing the mechanism of host immune responses and decipher the progression of COVID-19 and providing important clues for combating this pandemic. In this review, we summarize the roles of NK cells in viral infection and sepsis as well as the potential possibilities of NK cell-based immunotherapy for treating COVID-19.

Monitoring immunomodulation in patients with sepsis

Introduction: This review aims to summarize current progress of the last ten years in the development of biomarkers used for classifying the immune response of the septic host and for monitoring the efficacy of the applied adjunctive immunotherapy.Areas covered: An extensive search of the literature was performed. In this review the authors discuss available biomarkers of host immune response in sepsis toward two directions; immunosuppression and hyperinflammation. Ferritin, sCD163, sIL-2 ra, and IL-18 may help in the diagnosis of macrophage activation syndrome (MAS) complicating sepsis whereas lymphopenia, decreased HLA-DR expression on monocytes, overexpression of Programmed cell death protein-1 (PD-1)/Programmed death-ligand 1 (PD-L1) and IL-10 are indicators of sepsis-induced immunosuppression. Novel approaches in the classification of immune state in sepsis include Myeloid-Derived Suppressor Cells (MDSC) and specific endotypes, defined by gene expression and molecular techniques.Expert opinion: HLA-DR and ferritin are the most commonly used biomarkers to monitor immunomodulation in clinical practice whereas developing specific sepsis endotypes is the future target. New immunotherapy trials in sepsis need to incorporate biomarkers for a personalized treatment.

Immunoglobulin-Like Transcript 5 Inhibits Macrophage-Mediated Bacterial Killing and Antigen Presentation During Sepsis

BACKGROUND

Immunosuppression contributes to the mortality of sepsis. However, the underlying mechanism remains unclear.

METHODS

In the present study, we investigated the role of inhibitory receptor immunoglobulin-like transcript 5 (ILT5) in sepsis. We first screened the expression of ILT family members, and we found that ILT5 was dramatically up-regulated in the peripheral blood mononuclear cells from sepsis patients versus healthy donors.

RESULTS

Knockdown of ILT5 by small interfering ribonucleic acid increased bacterial killing and reactive oxygen species production in THP-1 and RAW264.7 cells. Moreover, ILT5-expressing monocytes/macrophages exhibited lower expression of antigen-presenting molecules including major histocompatibility complex-II and CD80. In the in vitro coculture system with monocytes/macrophages, blockage of ILT5 facilitated Th1 proliferation and differentiation of CD4+ T cells. Furthermore, in vivo experiments demonstrated that pretreatment with ILT5 blocking peptide improved the survival and pulmonary pathology of septic mice.

CONCLUSIONS

Together, our study identified ILT5 as an immunosuppressive regulator during sepsis, which may provide potential therapeutic strategy for sepsis.

Role of procalcitonin, Il-6 and C- reactive protein in suspected cases of sepsis

OBJECTIVES

To study the role of serum procalcitonin as a diagnostic biomarker in sepsis and to compare it with other sepsis markers (IL-6, CRP) in patients of suspected sepsis.

MATERIALS AND METHODS

A total of 80 patients were included in this study from ICU and each patient was investigated for serum Procalcitonin, Interleukin-6 and C-reactive protein levels by ELISA along with blood cultures by BacT/Alert system.

RESULT

Procalcitonin along with CRP is a better diagnostic tool for sepsis.

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.

Effect of Eucommia ulmoides Oliv., Gynostemma pentaphyllum (Thunb.) Makino, and Curcuma longa L. on Th1- and Th2-cytokine responses and human leukocyte antigen-DR expression in peripheral blood mononuclear cells of septic patients

ETHNOPHARMACOLOGICAL RELEVANCE

Many traditional Chinese medicines (TCM), such as Eucommia ulmoides Oliv., Gynostemma pentaphyllum (Thunb.) Makino, and Curcuma longa L., have been reported to have various immune-modulatory effects.

AIM OF THE STUDY

To determine the effects of extracts from these three TCM on type 1 T help (Th1)- and Th2-cytokine responses and human leukocyte antigen (HLA)-DR expression in peripheral blood mononuclear cells (PBMCs) obtained from septic patients.

MATERIALS AND METHODS

Lipopolysaccharide (LPS)-stimulated PBMCs of healthy controls and septic patients were cultured for 48 hs with or without 0.05/0.1 mg/ml of TCM extract. HLA-DR expression in monocytes was detected using flow cytofluorimetry. The interferon [IFN]-γ, tumor necrosis factor [TNF]-α, interleukin (IL)- 2, IL-5, IL-10, and IL-13 levels in supernatants were measured with a human enzyme-linked immunosorbent assay.

RESULTS

Treatment with either 0.05 or 0.1 mg/ml of C. longa L. extract significantly restored the percentage of HLA-DR-positive monocytes, which was decreased by LPS in control and patient groups. Treatment with 0.05 or 0.1 mg/ml E. ulmoides Oliv. and C.longa L. extract decreased IL-10 production from LPS-stimulated PBMCs of controls and patients. In patients with sepsis, C. longa L. extract decreased IL-10 production to a greater degree than did E. ulmoides Oliv extract. Although IFN-γ, TNF-α, or IL-13 productions from LPS-stimulated PBMCs were influenced by E. ulmoides Oliv., G. pentaphyllum (Thunb.) Makino, or C. longa L. in control or sepsis groups in this study, only the influence of IL-10 was consistent in both control and sepsis groups.

CONCLUSIONS

By enhancing monocyte HLA-DR expression and decreasing IL-10 production, C. longa L. might help restore inflammatory responses in septic patients to eradicate pathogens.

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.

Immune Activation in Sepsis

Sepsis is caused by a dysregulated host response to infection. Immune responses determine the characteristics of sepsis. The body's protection against infection involves danger signal surveillance and recognition from nonself, effector functions in response to sensing danger signals, homeostatic regulation, and generation of immunologic memory. During sepsis, the immune system is activated by pathogen-associated and host-derived molecular patterns. Detecting these molecular patterns generates multisystem responses. Impaired organ function remote to the site of infection is the unifying feature. The processes by which an appropriate response to a microbial invader change from adaptive to maladaptive and dysregulated remain unclear.

High Interleukin-10 Expression in Type 2 T Helper Cells in Septic Patients

Interleukin (IL)-10 response is associated with mortality in patients with sepsis. IL-10 is primarily produced by monocytes and type 2 T helper (Th2) cells. The aim of this study was to investigate differences in IL-10 production between monocytes and Th2 cells in patients with sepsis. Forty patients with sepsis and 35 healthy controls were enrolled. Cytokine expressions in peripheral blood mononuclear cells (PBMCs) were measured by flow cytometry. The IL-10 expression in the Th2 cells of the septic patients was higher than in the healthy controls, but the expression of IL-10 in the monocytes of the septic patients was lower than in the healthy controls. After regression analysis, IL-10 expression in Th2 cells was positively associated with sepsis, but IL-10 expression in monocytes was not associated with sepsis or shock. In conclusion, the production of IL-10 in Th2 cells was higher in the patients with sepsis.

Monocyte and lymphocyte surface molecules in severe sepsis and non-septic critically ill Patients

The aim of the present study was to investigate whether expression of monocyte and lymphocyte surface molecules differs between patients with severe sepsis and non-septic patients treated in the intensive care unit (ICU). The expression of monocyte CD14, CD40, CD80 and HLA-DR, and lymphocyte CD69 were analyzed using quantitative flow cytometry on three consecutive days in 27 patients with severe sepsis and in 15 non-septic patients. Receiver operating characteristic analyses were performed and each corresponding area under the curve (AUC) was determined. The results showed that the expression levels of CD40 on monocytes and CD69 on CD4+ T cells and on natural killer (NK) cells were highest in patients with severe sepsis (p < 0.05). Monocyte CD40 and NK cell CD69 expression levels were higher in patients with severe sepsis and positive blood culture compared with those with negative blood culture (p < 0.05). The highest values of AUC for severe sepsis detection were 0.836 for CD40, 0.872 for CD69 on NK cells, and 0.795 for CD69 on CD4+ T cells. These findings suggest that monocyte CD40 and CD69 on NK cells and CD4+ T cells could prove useful for new approaches in the identification of severe sepsis in the ICU.

Low-Dose Steroid Therapy Is Associated with Decreased IL-12 Production in PBMCs of Severe Septic Patients

Background. Sepsis-induced immunosuppression may result in higher mortality rates in patients. Methods. We examined the relationship of cytokine responses from stimulated peripheral blood mononuclear cells (PBMCs) and monocyte human leukocyte antigen-DR (HLA-DR) expression (days 1 and 7) with low-dose steroid therapy in 29 septic patients. Patients were treated according to the guidelines. Thirty healthy controls were enrolled for validation. Results. Eighteen patients were prescribed low-dose steroids and 11 were not. Interleukin- (IL-) 12 responses in patients without low-dose steroid therapy on days 1 and 7 were higher than those with low-dose steroid therapy. Compared to day 1, IL-12 responses significantly increased on day 7 in patients without low-dose steroid therapy. After regression analysis, the change in the IL-12 response from day 7 to day 1 was found to be independently associated with the low-dose steroid therapy. There was no difference in monocyte HLA-DR expression between patients treated with and without low-dose steroid on day 1 or 7. No change in monocyte HLA-DR expression from day 7 to day 1 was observed in patients with or without low-dose steroid therapy. Conclusion. Decreased IL-12 response was associated with the low-dose steroid therapy in PBMCs of septic patients.

Endotoxin-Induced Tryptophan Degradation along the Kynurenine Pathway: The Role of Indolamine 2,3-Dioxygenase and Aryl Hydrocarbon Receptor-Mediated Immunosuppressive Effects in Endotoxin Tolerance and Cancer and Its Implications for Immunoparalysis

The degradation of tryptophan (TRP) along the kynurenine pathway plays a crucial role as a neuro- and immunomodulatory mechanism in response to inflammatory stimuli, such as lipopolysaccharides (LPS). In endotoxemia or sepsis, an enhanced activation of the rate-limiting enzyme indoleamine 2,3-dioxygenase (IDO) is associated with a higher mortality risk. It is assumed that IDO induced immunosuppressive effects provoke the development of a protracted compensatory hypoinflammatory phase up to a complete paralysis of the immune system, which is characterized by an endotoxin tolerance. However, the role of IDO activation in the development of life-threatening immunoparalysis is still poorly understood. Recent reports described the impact of inflammatory IDO activation and aryl hydrocarbon receptor- (AhR-) mediated pathways on the development of LPS tolerance and immune escape of cancer cells. These immunosuppressive mechanisms offer new insights for a better understanding of the development of cellular dysfunctions in immunoparalysis. This review provides a comprehensive update of significant biological functions of TRP metabolites along the kynurenine pathway and the complex regulation of LPS-induced IDO activation. In addition, the review focuses on the role of IDO-AhR-mediated immunosuppressive pathways in endotoxin tolerance and carcinogenesis revealing the significance of enhanced IDO activity for the establishment of life-threatening immunoparalysis in sepsis.

Measurement in saliva from neurotypical adults of biomarkers pertinent to autism spectrum disorders

Aim:

Measure biomarkers pertinent to autism in saliva from humans.

Materials & methods:

At 7:30 PM (reading instructions) and 8:30 PM (hearing instructions), neurotypical adults (6 M, 6 F) each spat into tubes containing protease inhibitors. Cells were counted, samples aliquoted, frozen and thawed. Rationale was given for choice of biomarkers. ELISA: CD26, IL-12, carnitine, C4B, GSH, GSSG, MT-2, testosterone, IFN-γ. Mass spectrometry: cystine, glutamine, glutamic acid, GABA, serotonin. Electrochemiluminescentimmunoassay: cortisol. Radioimmunoassay: melatonin.

Results:

Cells averaged 2.16 × 10⁶/ml. M > F: CD-26, C4B, MT-2. Testosterone, cortisol. Glutamine, glutamic acid, IFN-γ, melatonin and GSSG were measurable. Remaining biomarkers were measured in <50% of samples. Concentrations were equal at both times.

Conclusion:

Saliva can be collected by literate individuals without added instruction. Ten biomarkers were measurable.

Establishing a biomarker for postoperative ileus in humans - Results of the BiPOI trial

AIMS

Postoperative ileus (POI) is a frequent complication after abdominal surgery, resulting from an inflammation of the muscularis externa (ME). So far no valid biomarker for occurrence, duration or intensity of POI exists. Extravasation of monocytes and neutrophils from blood circulating into the postoperative ME is well known as a hallmark of POI. In a previous study we demonstrated that a low abundant subset of TH1 cells, activated by IL-12, can be detected in the peripheral blood of a small subset of patients in response to abdominal surgery. The aim of the present study was to investigate if these specific TH1 cells, IL-12 or circulating leukocyte levels could act as a valid marker for POI occurrence.

MAIN METHODS

At different time points, blood samples of patients undergoing abdominal or extraabdominal surgery were collected. Serum levels of IL-12 or TH1 cells as well as neutrophils and monocytes were analyzed. Data were compared between both groups and correlated with clinical signs of POI.

KEY FINDINGS

Time until first flatus and defecation as well as solid food tolerances are delayed after abdominal compared to extraabdominal surgery. Circulating IL-12 levels and numbers of TH1 cells, neutrophils and monocytes did not differ between both groups.

SIGNIFICANCE

While previous experiments indicated that specific TH1 cells play a crucial role in POI dissemination, our present data from a larger human cohort demonstrate that they do not seem to be suitable to distinguish between abdominal and extraabdominal surgery. Furthermore neither TH1 cells nor leukocytes or serum IL-12 levels are appropriate biomarkers for POI in a clinical setting.

Biomarkers in polytrauma induced systemic inflammatory response syndrome and sepsis - a narrative review

Polytrauma still represents one of the leading causes of death in the first four decades of life. Septic complications represent the predominant causes of late death in polytrauma patients. Early diagnosis and treatment of infection is associated with an improved clinical outcome and reduced mortality. Several biomarkers have been evaluated for making early diagnosis of sepsis. Current evidence does not support the use of a single biomarker in diagnosing septic complications. Procalcitonin trend was found to be useful in early identification of post-traumatic sepsis.

Immunological characterization of compensatory anti-inflammatory response syndrome in patients with severe sepsis: a longitudinal study*

OBJECTIVES

To perform a complete immunological characterization of compensatory anti-inflammatory response syndrome in patients with sepsis and to explore the relationship between these changes and clinical outcomes of 28-day mortality and secondary infections.

DESIGN

Prospective single-center study conducted between April 2011 and December 2012.

SETTING

ICUs from Hospital Universitario San Vicente Fundación at Medellin, Colombia.

PATIENTS

One hundred forty-eight patients with severe sepsis.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

At days 0, 1, 3, 5, 10, and 28, we determined the expression of HLA-DR in monocytes and the apoptosis and the proliferation index in T lymphocytes, as well as the levels of tumor necrosis factor-α, interleukin-6, interleukin-1β, interleukin-10, and transforming growth factor-β in both plasma and cell culture supernatants of peripheral blood mononuclear cells. The mean percentage of HLA-DR was 60.7 at enrollment and increased by 0.9% (95% CI, 0.7-1.2%) per day. The mean percentage of CD4 T cells and CD8 T cells AV+/7-AAD- at enrollment was 37.2% and 20.4%, respectively, but it diminished at a rate of -0.5% (95% CI, -0.7% to -0.3%) and -0.3% (95% CI, -0.4% to -0.2%) per day, respectively. Plasma levels of interleukin-6 and interleukin-10 were 290 and 166 pg/mL and decreased at a rate of -7.8 pg/mL (95% CI, -9.5 to -6.1 pg/mL) and -4 pg/mL (95% CI, -5.1 to -2.8 pg/mL) per day, respectively. After controlling for confounders, only sustained plasma levels of interleukin-6 increase the risk of death (hazard ratio 1.003; 95% CI, 1.001-1.006).

CONCLUSIONS

We found no evidence to support a two-phase model of sepsis pathophysiology. However, immunological variables did behave in a mixed and time-dependent manner. Further studies should evaluate changes over time of interleukin-6 plasma levels as a prognostic biomarker for critically ill patients.

Sepsis: multiple abnormalities, heterogeneous responses, and evolving understanding

Sepsis represents the host's systemic inflammatory response to a severe infection. It causes substantial human morbidity resulting in hundreds of thousands of deaths each year. Despite decades of intense research, the basic mechanisms still remain elusive. In either experimental animal models of sepsis or human patients, there are substantial physiological changes, many of which may result in subsequent organ injury. Variations in age, gender, and medical comorbidities including diabetes and renal failure create additional complexity that influence the outcomes in septic patients. Specific system-based alterations, such as the coagulopathy observed in sepsis, offer both potential insight and possible therapeutic targets. Intracellular stress induces changes in the endoplasmic reticulum yielding misfolded proteins that contribute to the underlying pathophysiological changes. With these multiple changes it is difficult to precisely classify an individual's response in sepsis as proinflammatory or immunosuppressed. This heterogeneity also may explain why most therapeutic interventions have not improved survival. Given the complexity of sepsis, biomarkers and mathematical models offer potential guidance once they have been carefully validated. This review discusses each of these important factors to provide a framework for understanding the complex and current challenges of managing the septic patient. Clinical trial failures and the therapeutic interventions that have proven successful are also discussed.

Upregulation of the inhibitory receptor ILT4 in monocytes from septic patients

Sepsis-induced immune dysfunction is a complex phenomenon that involves both innate and adaptive responses. Upregulation of the inhibitor receptor named immunoglobulin like transcript 4 (ILT4) is crucial to the tolerogenic function of monocytes. Here, ILT4 expression, endotoxin-induced IL-12 and IL-10 production and CD86 expression were investigated in circulating monocytes from 16 patients with severe sepsis and 16 age and sex matched controls. We found that monocytes from patients with severe sepsis express significantly higher levels of ILT4 than monocytes from controls. Upregulation of ILT4 expression appeared to be induced by soluble factors present in the serum of septic patients and directly correlated with the degree of organ dysfunction. ILT4(+) monocytes from septic patients also displayed an alteration in the cytokine response to endotoxin stimulation characterized by reduced IL-12 production and increased IL-10 production, and a reduced expression of the costimulatory molecule CD86. In conclusion, the increased ILT4 expression and IL-10 production and the decreased CD86 expression and IL-12 production indicate that during sepsis monocytes undergo substantial modulation of the surface and cytokine phenotype. These phenotypic changes may interfere with the antigen presenting cell activity of monocytes, which may contribute to the impairment of adaptive immune responses that takes place during sepsis.

Cytokines in sepsis: potent immunoregulators and potential therapeutic targets--an updated view

Sepsis and septic shock are among the leading causes of death in intensive care units worldwide. Numerous studies on their pathophysiology have revealed an imbalance in the inflammatory network leading to tissue damage, organ failure, and ultimately, death. Cytokines are important pleiotropic regulators of the immune response, which have a crucial role in the complex pathophysiology underlying sepsis. They have both pro- and anti-inflammatory functions and are capable of coordinating effective defense mechanisms against invading pathogens. On the other hand, cytokines may dysregulate the immune response and promote tissue-damaging inflammation. In this review, we address the current knowledge of the actions of pro- and anti-inflammatory cytokines in sepsis pathophysiology as well as how these cytokines and other important immunomodulating agents may be therapeutically targeted to improve the clinical outcome of sepsis.

Associations of T helper 1, 2, 17 and regulatory T lymphocytes with mortality in severe sepsis

Objective and design

T helper 17 (Th17) and regulatory T (T_reg) lymphocytes might play important roles in patients with severe sepsis. The association of Th17 or T_reg lymphocytes with survival is also unclear.

Methods

Eighty-seven patients with severe sepsis were enrolled from our intensive care units between August 2008 and July 2010. Leukocyte antigens and clinical data were determined on day 1 in all patients and on day 7 in first-year patients.

Results

The percentages in peripheral blood mononuclear cells (PBMCs) and circulatory counts of CD4⁺ and CD8⁺ lymphocytes in survivors were higher than those in non-survivors. Th1/CD4⁺ ratios and circulatory Th1 lymphocyte counts in survivors were higher than in non-survivors. Absolute counts of Th17 and T_reg lymphocytes in survivors were higher than in non-survivors. The percentages of CD4⁺ and CD8⁺ in survivors’ PBMCs were increased after 6 days. Th17/CD4⁺ ratios and circulatory Th17 lymphocyte counts in survivors were increased after 6 days.

Conclusions

Higher Th1 differentiation and total CD4⁺ T lymphocyte counts were associated with higher survival. The association of circulatory Th17 and T_reg lymphocytes with mortality in severe sepsis may be due to the change in total CD4⁺ T lymphocytes. In survivors, Th17 differentiation and counts were restored.

Role of an iron-dependent transcriptional regulator in the pathogenesis and host response to infection with Streptococcus pneumoniae

Iron is a critical cofactor for many enzymes and is known to regulate gene expression in many bacterial pathogens. Streptococcus pneumoniae normally inhabits the upper respiratory mucosa but can also invade and replicate in lungs and blood. These anatomic sites vary considerably in both the quantity and form of available iron. The genome of serotype 4 pneumococcal strain TIGR4 encodes a putative iron-dependent transcriptional regulator (IDTR). A mutant deleted at idtr (Δidtr) exhibited growth kinetics similar to parent strain TIGR4 in vitro and in mouse blood for up to 48 hours following infection. However, Δidtr was significantly attenuated in a murine model of sepsis. IDTR down-regulates the expression of ten characterized and putative virulence genes in nasopharyngeal colonization and pneumonia. The host cytokine response was significantly suppressed in sepsis with Δidtr. Since an exaggerated inflammatory response is associated with a poor prognosis in sepsis, the decreased inflammatory response could explain the increased survival with Δidtr. Our results suggest that IDTR, which is dispensable for pneumococcal growth in vitro, is associated with regulation of pneumococcal virulence in specific host environments. Additionally, IDTR ultimately modulates the host cytokine response and systemic inflammation that contributes to morbidity and mortality of invasive pneumococcal disease.