Circulating mitochondrial N-formyl peptides contribute to secondary nosocomial infection in patients with septic shock.
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ABSTRACT:
SUBMITTER: Kwon WY
PROVIDER: S-EPMC8092466 | biostudies-literature |
REPOSITORIES: biostudies-literature
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Project description:Sepsis syndrome represents the leading cause of death in intensive care unit. Patients present features consistent with a decline in immune responsiveness potentially contributing to mortality. We investigated whether CD4(+)CD25(+) regulatory T cells (Treg) participate in the induction of lymphocyte anergy after sepsis.Observational study in septic shock patients and experimental study in mice.We took advantage of the recently described flow cytometric gating strategy using the measurement of CD25 and CD127 expressions for monitoring Treg (CD4(+)CD25(+)CD127(-)Foxp3(+)). In patients the increased circulating Treg percentage significantly correlated with a decreased lympho-proliferative response. In a murine model of sepsis mimicking these observations, the ex vivo downregulation of Foxp3 expression using siRNA was associated with a restoration of this response.The relative increase in circulating Treg might play a role in lymphocyte anergy described after septic shock and represent a standardizable surrogate marker of declining proliferative capacity after sepsis.
| S-EPMC2789433 | biostudies-literature
Project description:Sepsis, which is the leading cause of death in intensive care units (ICU), has been acknowledged as a global health priority by the WHO in 2017. Identification of biomarkers allowing early stratification and recognition of patients at higher risk of death is crucial. One promising biomarker candidate is pentraxin-3 (PTX3); initially elevated and persistently increased plasma concentration in septic patients has been associated with increased mortality. PTX3 is an acute phase protein mainly stored in neutrophil granules. These cells are responsible for rapid and prompt release of PTX3 in inflammatory context, but the cellular origin responsible for successive days' elevation in sepsis remains unknown. Upon inflammatory stimulation, PTX3 can also be produced by other cell types, including endothelial and immune cells. As in septic patients immune alterations have been described, we therefore sought to investigate whether such cells participated in the elevation of PTX3 over the first days after septic shock onset. To address this point, PTX3 was measured in plasma from septic shock patients at day 3 after ICU admission as well as in healthy volunteers (HV), and the capacity of whole blood cells to secrete PTX3 after inflammatory stimulation was evaluated ex vivo. A significantly mean higher (100-fold) concentration of plasma PTX3 was found in patients compared to HV, which was likely due to the inflammation-induced initial release of the pre-existing PTX3 reservoir contained in neutrophils. Strikingly, when whole blood was stimulated ex vivo with LPS no significant difference between patients and HV in PTX3 release was found. This was in contrast with TNFα which decreased production was illustrative of the endotoxin tolerance phenomenon occurring in septic patients. Then, the release of PTX3 protein from a HV neutrophil-free PBMC endotoxin tolerance model was investigated. At the transcriptional level, PTX3 seems to be a weakly tolerizable gene similar to TNFα. Conversely, increased protein levels observed in anergy condition reflects a non-tolerizable phenotype, more likely to an anti-inflammatory marker. Hence, altered immune cells still have the ability to produce PTX3 in response to an inflammatory trigger, and therefore circulating white blood cell subset could be responsible of the sustained PTX3 plasma levels over the first days of sepsis setting.
| S-EPMC6338061 | biostudies-literature
Project description:Major surgery is regularly associated with clinical signs of systemic inflammation, which potentially affects the rapid identification of sepsis. Therefore, this secondary analysis of an observational study aims to determine whether NADH dehydrogenase 1 (ND1) mitochondrial DNA (mtDNA) could be used as a potential biomarker for the discrimination between septic shock and postsurgical systemic inflammation. Overall, 80 patients were included (septic shock (n = 20), cardiac artery bypass grafting (CABG, n = 20), major abdominal surgery (MAS, n = 20), and matched controls (CTRL, n = 20)). Quantitative PCR was performed to measure ND1 mtDNA. Thromboelastography was used to analyze the coagulatory system. Free-circulating ND1 mtDNA levels were significantly higher in septic shock patients compared to patients suffering from post-surgical inflammation ({copies/µL}: CTRL: 1208 (668-2685); septic shock: 3823 (2170-7318); CABG: 1272 (417-2720); and MAS: 1356 (694-2845); CTRL vs. septic shock: p < 0.001; septic shock vs. CABG: p < 0.001; septic shock vs. MAS: p = 0.006; CABG vs. MAS: p = 0.01). ND1 mtDNA levels in CABG patients showed a strong positive correlation with fibrinogen (correlation coefficient [r]= 0.57, p < 0.001) and fibrinogen-dependent thromboelastographic assays (maximum clot firmness, EXTEM: r = 0.35, p = 0.01; INTEM: r = 0.31, p = 0.02; FIBTEM: r = 0.46, p < 0.001). In conclusion, plasma levels of free-circulating ND1 mtDNA were increased in septic shock patients and were discriminative between sepsis and surgery-induced inflammation. Furthermore, this study showed an association between ND1 mtDNA and a fibrinogen-dependent pro-coagulatory shift in cardiac surgical patients.
| S-EPMC7408641 | biostudies-literature
Project description:ObjectivesLiterature suggests that neutrophils of patients with rheumatoid arthritis (RA) are primed to respond to N-formyl methionine group (formylated peptides). Animal models indicate that formylated peptides contribute to joint damage via neutrophil recruitment and inflammation in joints. Non-steroidal anti-inflammatory drugs are also known to inhibit formyl peptide-induced neutrophil activation. The predominant source of formylated peptides in sterile inflammatory conditions like RA is mitochondria, organelles with prokaryotic molecular signatures. However, there is no direct evidence of mitochondrial formyl peptides (mtNFPs) in the circulation of patients with RA and their potential role in neutrophil-mediated inflammation in RA, including their clinical significance.MethodsLevels of mtNFPs (total fMet, MT-ND6) were analyzed using ELISA in plasma and serum obtained from patients in 3 cross-sectional RA cohorts (n = 275), a longitudinal inception cohort (n = 192) followed for a median of 8 years, and age/gender-matched healthy controls (total n = 134). Neutrophil activation assays were done in the absence or presence of formyl peptide receptor 1 (FPR1) inhibitor cyclosporine H.ResultsElevated levels of total fMet were observed in the circulation of patients with RA as compared to healthy controls (p < 0.0001) associating with disease activity and could distinguish patients with the active disease from patients with inactive disease or patients in remission. Baseline levels of total fMet correlated with current and future joint involvement, respectively and predicted the development of rheumatoid nodules (OR = 1.2, p = 0.04). Further, total fMet levels improved the prognostic ability of ACPA in predicting erosive disease (OR of 7.9, p = 0.001). Total fMet levels correlated with markers of inflammation and neutrophil activation. Circulating mtNFPs induced neutrophil activation in vitro through FPR1-dependent mechanisms.ConclusionsCirculating mtNFPs could be novel biomarkers of disease monitoring and prognosis for RA and in investigating neutrophil-mediated inflammation in RA. We propose, FPR1 as a novel therapeutic target for RA.
| S-EPMC8062236 | biostudies-literature
Project description:Background: Septic shock, a major cause of death in critical care, is the clinical translation of a cytokine storm in response to infection. It can be complicated by sepsis-induced immunosuppression, exemplified by blood lymphopenia, an excess of circulating Treg lymphocytes, and decreased HLA-DR expression on circulating monocytes. Such immunosuppression is associated with secondary infections, and higher mortality. The effect of these biological modifications on circulating innate lymphoid cells (ILCs) has been little studied. Methods: We prospectively enrolled patients with septic shock (Sepsis-3 definition) in the intensive care unit (ICU) of Timone CHU Hospital. ICU controls (trauma, cardiac arrest, neurological dysfunction) were recruited at the same time (NCT03297203). We performed immunophenotyping of adaptive lymphocytes (CD3+ T cells, CD19+ B cells, CD4+CD25+FoxP3+ Treg lymphocytes), ILCs (CD3-CD56+ NK cells and helper ILCs - ILC1, ILC2, and ILC3), and monocytes by flow cytometry on fresh blood samples collected between 24 and 72 h after admission. Results: We investigated adaptive and innate circulating lymphoid cells in the peripheral blood of 18 patients in septic shock, 15 ICU controls, and 30 healthy subjects. As expected, the peripheral blood lymphocytes of all ICU patients showed lymphopenia, which was not specific to sepsis, whereas those of the healthy volunteers did not. Circulating CD3+ T cells and CD3-CD56+ NK cells were mainly concerned. There was a tendency toward fewer Treg lymphocytes and lower HLA-DR expression on monocytes in ICU patients with sepsis. Although the ILC1 count was higher in septic patients than healthy subjects, ILC2, and ILC3 counts were lower in both ICU groups. However, ILC3s within the total ILCs were overrepresented in patients with septic shock. The depression of immune responses has been correlated with the occurrence of secondary infections. We did not find any differences in ILC distribution according to this criterion. Conclusion: All ICU patients exhibit lymphopenia, regardless of the nature (septic or sterile) of the initial medical condition. Specific distribution of circulating ILCs, with an excess of ILC1, and a lack of ILC3, may characterize septic shock during the first 3 days of the disease.
| S-EPMC6763762 | biostudies-literature
Project description:Secondary infection in septic patients has received widespread attention, although clinical data are still lacking. The present study was performed on 476 patients with septic shock. Time trends for mortality were analyzed using Spearman's rank correlation test. Risk factors for secondary infection were investigated by binary logistic regression. The extended Cox model with time-varying covariates and hazard ratios (HR) was performed to determine the impact of secondary infection on mortality. Differences in hospital length of stay (LOS) between patients with and without secondary infection were calculated using a multistate model. Thirty-nine percent of septic shock patients who survived the early phase of the disease developed secondary infection. There was a statistically significant increased odds ratio for secondary infection in older patients and patients with a longer LOS in the intensive care unit (ICU), a higher Sequential Organ Failure Assessment (SOFA) score, and endotracheal intubation. Secondary infection significantly reduced the rate of discharge (HR 5.607; CI95 3.612-8.704; P < 0.001) and was associated with an increased hospital LOS of 5.46 days. The present findings represent a direct description of secondary infection in septic shock patients and highlight the influence of this condition on septic shock outcomes.
| S-EPMC5141415 | biostudies-literature
Project description:BACKGROUND:Fluid boluses are administered to septic shock patients with the purpose of increasing cardiac output as a means to restore tissue perfusion. Unfortunately, fluid therapy has a narrow therapeutic index, and therefore, several approaches to increase safety have been proposed. Fluid responsiveness (FR) assessment might predict which patients will effectively increase cardiac output after a fluid bolus (FR+), thus preventing potentially harmful fluid administration in non-fluid responsive (FR-) patients. However, there are scarce data on the impact of assessing FR on major outcomes. The recent ANDROMEDA-SHOCK trial included systematic per-protocol assessment of FR. We performed a post hoc analysis of the study dataset with the aim of exploring the relationship between FR status at baseline, attainment of specific targets, and clinically relevant outcomes. METHODS:ANDROMEDA-SHOCK compared the effect of peripheral perfusion- vs. lactate-targeted resuscitation on 28-day mortality. FR was assessed before each fluid bolus and periodically thereafter. FR+ and FR- subgroups, independent of the original randomization, were compared for fluid administration, achievement of resuscitation targets, vasoactive agents use, and major outcomes such as organ dysfunction and support, length of stay, and 28-day mortality. RESULTS:FR could be determined in 348 patients at baseline. Two hundred and forty-two patients (70%) were categorized as fluid responders. Both groups achieved comparable successful resuscitation targets, although non-fluid responders received less resuscitation fluids (0 [0-500] vs. 1500 [1000-2500] mL; p 0.0001), exhibited less positive fluid balances, but received more vasopressor testing. No difference in clinically relevant outcomes between FR+ and FR- patients was found, including 24-h SOFA score (9 [5-12] vs. 8 [5-11], p = 0.4), need for MV (78% vs. 72%, p = 0.16), need for RRT (18% vs. 21%, p = 0.7), ICU-LOS (6 [3-11] vs. 6 [3-16] days, p = 0.2), and 28-day mortality (40% vs. 36%, p = 0.5). Only thirteen patients remained fluid responsive along the intervention period. CONCLUSIONS:Systematic assessment allowed determination of fluid responsiveness status in more than 80% of patients with early septic shock. Fluid boluses could be stopped in non-fluid responsive patients without any negative impact on clinical relevant outcomes. Our results suggest that fluid resuscitation might be safely guided by FR assessment in septic shock patients. TRIAL REGISTRATION:ClinicalTrials.gov identifier, NCT03078712. Registered retrospectively on March 13, 2017.
| S-EPMC6979284 | biostudies-literature
Project description:In an ongoing translational research program involving microarray-based expression profiles in pediatric septic shock, we have now conducted longitudinal studies focused on the temporal expression profiles of canonical signaling pathways and gene networks. Genome-level expression profiles were generated from whole blood-derived RNA samples of children with septic shock (n = 30 individual patients) corresponding to days 1 and 3 of admission to the pediatric intensive care unit. Based on sequential statistical and expression filters, day 1 and day 3 of septic shock were characterized by differential regulation of 2,142 and 2,504 gene probes, respectively, relative to normal control patients. Venn analysis demonstrated 239 unique genes in the day 1 data set, 598 unique genes in the day 3 data set, and 1,906 genes common to both data sets. Analyses targeted toward derivation of biological function from these data sets demonstrated time-dependent, differential regulation of genes involved in multiple canonical signaling pathways and gene networks primarily related to immunity and inflammation. Notably, multiple and distinct gene networks involving T cell- and MHC antigen-related biological processes were persistently downregulated from day 1 to day 3. Further analyses demonstrated large scale and persistent downregulation of genes corresponding to functional annotations related to zinc homeostasis. These data represent the largest reported cohort of patients with septic shock, which has undergone longitudinal genome-level expression profiling. The data further advance our genome-level understanding of pediatric septic shock and support novel hypotheses that can be readily tested at both the experimental and translational levels. Keywords: Inflammation; sepsis; innate immunity; T cells; MHC antigen Keywords: to be updated
2007-06-14 | GSE8121 | GEO
Project description:BackgroundBiomarkers can be of help to understand critical illness and to identify and stratify sepsis. Adrenomedullin is a vasoactive hormone, with reported prognostic and potentially therapeutic value in sepsis. The primary aim of this study was to investigate the association of circulating bioactive adrenomedullin (bio-ADM) levels at intensive care unit (ICU) admission with mortality in sepsis patients and in a general ICU population. Secondary aims included the association of bio-ADM with organ failure and the ability of bio-ADM to identify sepsis.MethodsIn this retrospective observational study, adult patients admitted to one of four ICUs during 2016 had admission bio-ADM levels analysed. Age-adjusted odds ratios (OR) with 95% CI for log-2 transformed bio-ADM, and Youden's index derived cut-offs were calculated. The primary outcome was 30-day mortality, and secondary outcomes included the need for organ support and the ability to identify sepsis.ResultsBio-ADM in 1867 consecutive patients were analysed; 632 patients fulfilled the sepsis-3 criteria of whom 267 had septic shock. The median bio-ADM in the entire ICU population was 40 pg/mL, 74 pg/mL in sepsis patients, 107 pg/mL in septic shock and 29 pg/mL in non-septic patients. The association of elevated bio-ADM and mortality in sepsis patients and the ICU population resulted in ORs of 1.23 (95% CI 1.07-1.41) and 1.22 (95% CI 1.12-1.32), respectively. The association with mortality remained after additional adjustment for lactate in sepsis patients. Elevated bio-ADM was associated with an increased need for dialysis with ORs of 2.28 (95% CI 2.01-2.59) and 1.97 (95% CI 1.64-2.36) for the ICU population and sepsis patients, respectively, and with increased need of vasopressors, OR 1.33 (95% CI 1.23-1.42) (95% CI 1.17-1.50) for both populations. Sepsis was identified with an OR of 1.78 (95% CI 1.64-1.94) for bio-ADM, after additional adjustment for severity of disease. A bio-ADM cut-off of 70 pg/mL differentiated between survivors and non-survivors in sepsis, but a Youden's index derived threshold of 108 pg/mL performed better.ConclusionsAdmission bio-ADM is associated with 30-day mortality and organ failure in sepsis patients as well as in a general ICU population. Bio-ADM may be a morbidity-independent sepsis biomarker.
| S-EPMC7641835 | biostudies-literature
Project description:IntroductionIncreasing evidence supports a role for mitochondrial dysfunction in organ injury and immune dysregulation in sepsis. Although differential expression of mitochondrial genes in blood cells has been reported for several diseases in which bioenergetic failure is a postulated mechanism, there are no data about the blood cell mitochondrial transcriptome in pediatric sepsis.MethodsWe conducted a focused analysis using a multicenter genome-wide expression database of 180 children ≤ 10 years of age with septic shock and 53 healthy controls. Using total RNA isolated from whole blood within 24 hours of PICU admission for septic shock, we evaluated 296 nuclear-encoded mitochondrial genes using a false discovery rate of 1%. A series of bioinformatic approaches were applied to compare differentially expressed genes across previously validated gene expression-based subclasses (groups A, B, and C) of pediatric septic shock.ResultsIn total, 118 genes were differentially regulated in subjects with septic shock compared to healthy controls, including 48 genes that were upregulated and 70 that were downregulated. The top scoring canonical pathway was oxidative phosphorylation, with general downregulation of the 51 genes corresponding to the electron transport system (ETS). The top two gene networks were composed primarily of mitochondrial ribosomal proteins highly connected to ETS complex I, and genes encoding for ETS complexes I, II, and IV that were highly connected to the peroxisome proliferator activated receptor (PPAR) family. There were 162 mitochondrial genes differentially regulated between groups A, B, and C. Group A, which had the highest maximum number of organ failures and mortality, exhibited a greater downregulation of mitochondrial genes compared to groups B and C.ConclusionsBased on a focused analysis of a pediatric septic shock transcriptomic database, nuclear-encoded mitochondrial genes were differentially regulated early in pediatric septic shock compared to healthy controls, as well as across genotypic and phenotypic distinct pediatric septic shock subclasses. The nuclear genome may be an important mechanism contributing to alterations in mitochondrial bioenergetic function and outcomes in pediatric sepsis.
| S-EPMC4247726 | biostudies-literature