Persistently Elevated Soluble Triggering Receptor Expressed on Myeloid Cells 1 and Decreased Monocyte Human Leucocyte Antigen DR Expression Are Associated With Nosocomial Infections in Septic Shock Patients.

Sepsis-acquired immunosuppression may play a major role in patients' prognosis through increased risk of secondary infections. Triggering receptor expressed on myeloid cells 1 (TREM-1) is an innate immune receptor involved in cellular activation. Its soluble form (sTREM-1) has been described as a robust marker of mortality in sepsis. The objective of this study was to evaluate its association with the occurrence of nosocomial infections alone or in combination with human leucocyte antigen-DR on monocytes (mHLA-DR). DESIGN: Observational study. SETTING: University Hospital in France. PATIENTS: One hundred sixteen adult septic shock patients as a post hoc study from the IMMUNOSEPSIS cohort (NCT04067674). INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Plasma sTREM-1 and monocyte HLA-DR were measured at day 1 or 2 (D1/D2), D3/D4, and D6/D8 after admission. Associations with nosocomial infection were evaluated through multivariable analyses. At D6/D8, both markers were combined, and association with increased risk of nosocomial infection was evaluated in the subgroup of patients with most deregulated markers in a multivariable analysis with death as a competing risk. Significantly decreased mHLA-DR at D6/D8 and increased sTREM-1 concentrations were measured at all time points in nonsurvivors compared with survivors. Decreased mHLA-DR at D6/D8 was significantly associated with increased risk of secondary infections after adjustment for clinical parameters with a subdistribution hazard ratio of 3.61 (95% CI, 1.39-9.34; p = 0.008). At D6/D8, patients with persistently high sTREM-1 and decreased mHLA-DR presented with a significantly increased risk of infection (60%) compared with other patients (15.7%). This association remained significant in the multivariable model (subdistribution hazard ratio [95% CI], 4.65 [1.98-10.9]; p < 0.001). CONCLUSIONS: In addition to its prognostic interest on mortality, sTREM-1, when combined with mHLA-DR, may help to better identify immunosuppressed patients at risk of nosocomial infections.

Immune Profiling Demonstrates a Common Immune Signature of Delayed Acquired Immunodeficiency in Patients With Various Etiologies of Severe Injury.

OBJECTIVES: The host response plays a central role in the pathophysiology of sepsis and severe injuries. So far, no study has comprehensively described the overtime changes of the injury-induced immune profile in a large cohort of critically ill patients with different etiologies. DESIGN: Prospective observational cohort study. SETTING: Adult ICU in a University Hospital in Lyon, France. PATIENTS: Three hundred fifty-three septic, trauma, and surgical patients and 175 healthy volunteers were included in the REAnimation Low Immune Status Marker study. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Extensive immune profiling was performed by assessing cellular phenotypes and functions, protein, and messenger RNA levels at days 1-2, 3-4, and 5-7 after inclusion using a panel of 30 standardized immune markers. Using this immunomonitoring panel, no specificity in the immune profile was observed among septic, trauma, and surgical patients. This common injury-induced immune response was characterized by an initial adaptive (i.e., physiologic) response engaging all constituents of the immune system (pro- and anti-inflammatory cytokine releases, and innate and adaptive immune responses) but not associated with increased risk of secondary infections. In contrary, the persistence in a subgroup of patients of profound immune alterations at the end of the first week after admission was associated with increased risk of secondary infections independently of exposure to invasive devices. The combined monitoring of markers of pro-/anti-inflammatory, innate, and adaptive immune responses allowed a better enrichment of patients with risk of secondary infections in the selected population. CONCLUSIONS: Using REAnimation Low Immune Status Marker immunomonitoring panel, we detected delayed injury-acquired immunodeficiency in a subgroup of severely injured patients independently of primary disease. Critically ill patients' immune status could be captured through the combined monitoring of a common panel of complementary markers of pro-/anti-inflammatory, innate, and adaptive immune responses. Such immune monitoring needs to be incorporated in larger study cohorts with more extensive immune surveillance to develop specific hypothesis allowing for identification of biological systems affecting altered immune function related to late infection in the setting of acute systemic injury.

Ultrasound guidance for urgent arterial and venous catheterisation: randomised controlled study.

BACKGROUND: Haemodynamically unstable patients often require arterial and venous catheter insertion urgently. We hypothesised that ultrasound-guided arterial and venous catheterisation would reduce mechanical complications. METHODS: We performed a prospective RCT, where patients requiring both urgent arterial and venous femoral catheterisation were randomised to either ultrasound-guided or landmark-guided catheterisation. Complications and characteristics of catheter insertion (procedure duration, number of punctures, and procedure success) were recorded at the time of insertion (immediate complications). Late complications were investigated by ultrasound examination performed between the third and seventh days after randomisation. Primary outcome was the proportion of patients with at least one mechanical complication (immediate or late), by intention-to-treat analysis. Secondary outcomes included success rate, procedure time, and number of punctures. RESULTS: We analysed 136 subjects (102 [75%] male; age range: 27-62 yr) by intention to treat. The proportion of subjects with one or more complications was lower in 22/67 (33%) subjects undergoing ultrasound-guided catheterisation compared with landmark-guided catheterisation (40/69 [58%]; odds ratio: 0.35 [95% confidence interval: 0.18-0.71]; P=0.003). Ultrasound-guided catheterisation reduced both immediate (27%, compared with 51% in the landmark approach group; P=0.004) and late (10%, compared with 23% in the landmark approach group; P=0.047) complications. Ultrasound guidance also reduced the proportion of patients who developed deep vein thrombosis (4%, compared with 22% following landmark approach; P=0.012), and achieved a higher procedural success rate (96% vs 78%; P=0.004). CONCLUSIONS: An ultrasound-guided approach reduced mechanical complications after urgent femoral arterial and venous catheterisation, while increasing procedural success. CLINICAL TRIAL REGISTRATION: NCT02820909.

Toward Monocyte HLA-DR Bedside Monitoring: A Proof-of-Concept Study.

OBJECTIVES: Decreased expression of human leukocyte antigen-DR on monocytes (mHLA-DR) is recognized as the most appropriate marker for the monitoring of immune alterations in septic patients and critically ill subjects. Its measurement has been established for years by flow cytometry, but remains under-used due to pre-analytical constraints. The objectives of the present work were to develop a rapid and robust one-step protocol. METHODS: A novel, simplified protocol has been developed to measure mHLA-DR in whole blood using flow cytometry. It is a one-step procedure that includes red cell lysis, antibodies, and fixative reagents. It has been compared to the standardized routine protocol in two consecutive cohorts of septic shock patients (n = 37). Finally, the protocol was applied to a few subjects in point-of-care settings, by collecting capillary blood from fingerpricks. RESULTS: Strong correlation was observed between the one-step method and routine protocol in 24 patients. After testing several stabilizing agents, the procedure was further optimized by adding a low-dose formaldehyde to the stain and lyse solution. This improved method was tested in a second cohort of 13 patients, and again strongly correlated to the routine protocol. Finally, the fingerprick and venous puncture samples were shown to provide similar results. CONCLUSIONS: The present work demonstrates the feasibility of a bedside protocol for flow cytometry measurement of mHLA-DR in critically ill subjects. This helps overcome pre-analytical constraints previously identified, which have limited wider use of this biomarker in intensive care units. In addition, preliminary results from fingerprick samples are promising.

Deciphering heterogeneity of septic shock patients using immune functional assays: a proof of concept study.

The complexity of sepsis pathophysiology hinders patient management and therapeutic decisions. In this proof-of-concept study we characterised the underlying host immune response alterations using a standardised immune functional assay (IFA) in order to stratify a sepsis population. In septic shock patients, ex vivo LPS and SEB stimulations modulated, respectively, 5.3% (1/19) and 57.1% (12/21) of the pathways modulated in healthy volunteers (HV), highlighting deeper alterations induced by LPS than by SEB. SEB-based clustering, identified 3 severity-based groups of septic patients significantly different regarding mHLA-DR expression and TNFα level post-LPS, as well as 28-day mortality, and nosocomial infections. Combining the results from two independent cohorts gathering 20 HV and 60 patients, 1 cluster grouped all HV with 12% of patients. The second cluster grouped 42% of patients and contained all non-survivors. The third cluster grouped 46% of patients, including 78% of those with nosocomial infections. The molecular features of these clusters indicated a distinctive contribution of previously described genes defining a "healthy-immune response" and a "sepsis-related host response". The third cluster was characterised by potential immune recovery that underlines the possible added value of SEB-based IFA to capture the sepsis immune response and contribute to personalised management.

Serum Concentrations of Lidocaine During Bariatric Surgery.

Lidocaine has been shown to be clinically beneficial during bariatric surgery. However, information about lidocaine serum concentrations in this setting is scarce. This prospective clinical trial included 42 obese patients undergoing laparoscopic bariatric surgery. They received lidocaine based on adjusted body weight. Administration began with a 1.5 mg·kg bolus of intravenous lidocaine followed by a continuous infusion of 2 mg·kg·hour. After skin closure, administration was decreased to 1 mg·kg·hour until discharge from the recovery room. No serum concentrations of lidocaine were outside the usual accepted range (1.5-5 µg·mL).

TCR activation mimics CD127lowPD-1high phenotype and functional alterations of T lymphocytes from septic shock patients.

BACKGROUND: Sepsis is the leading cause of mortality for critically ill patients worldwide. Patients develop T lymphocyte dysfunctions leading to T-cell exhaustion associated with increased risk of death. As interleukin-7 (IL-7) is currently tested in clinical trials to reverse these dysfunctions, it is important to evaluate the expression of its specific CD127 receptor on the T-cell surface of patients with septic shock. Moreover, the CD127lowPD-1high phenotype has been proposed as a T-cell exhaustion marker in chronic viral infections but has never been evaluated in sepsis. The objective of this study was first to evaluate CD127 and CD127lowPD-1high phenotype in septic shock in parallel with functional T-cell alterations. Second, we aimed to reproduce septic shock-induced T-cell alterations in an ex vivo model. METHODS: CD127 expression was followed at the protein and mRNA levels in patients with septic shock and healthy volunteers. CD127lowPD-1high phenotype was also evaluated in parallel with T-cell functional alterations after ex vivo activation. To reproduce T-cell alterations observed in patients, purified T cells from healthy volunteers were activated ex vivo and their phenotype and function were evaluated. RESULTS: In patients, neither CD127 expression nor its corresponding mRNA transcript level was modified compared with normal values. However, the percentage of CD127lowPD-1high T cells was increased while T cells also presented functional alterations. CD127lowPD-1high T cells co-expressed HLA-DR, an activation marker, suggesting a role for T-cell activation in the development of this phenotype. Indeed, T-cell receptor (TCR) activation of normal T lymphocytes ex vivo reproduced the increase of CD127lowPD-1high T cells and functional alterations following a second stimulation, as observed in patients. Finally, in this model, as observed in patients, IL-7 could improve T-cell proliferation. CONCLUSIONS: The proportion of CD127lowPD-1high T cells in patients was increased compared with healthy volunteers, although no global CD127 regulation was observed. Our results suggest that TCR activation participates in the occurrence of this T-cell population and in the development of T-cell alterations in septic shock. Furthermore, we provide an ex vivo model for the investigation of the pathophysiology of sepsis-induced T-cell immunosuppression and the testing of innovative immunostimulant treatments.

Low Interleukin-7 Receptor Messenger RNA Expression Is Independently Associated With Day 28 Mortality in Septic Shock Patients.

OBJECTIVES: Septic shock is the primary cause of death in ICUs. A better comprehension of its pathophysiology, in particular, the immune alteration mechanisms, opened new therapeutic perspectives such as the recombinant interleukin-7. The use of biomarkers could improve the identification of eligible patients for this therapy. The soluble form of the interleukin-7 appears as a promising candidate in this regard since an association between its high plasmatic level and mortality in critically ill patients has been demonstrated. Because there are no data available on the transcriptional regulation of the interleukin-7 receptor in such patients, this study aimed to explore the expression level of different interleukin-7 receptor transcripts after septic shock and evaluate their association with mortality. DESIGN: Retrospective discovery cohort (30 patients) and validation cohort (177 patients). SETTING: Two French ICUs (discovery study) and six French ICUs (validation study). PATIENTS: Adult septic shock patients. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: The quantification of several interleukin-7 receptor transcripts using specific reverse transcription quantitative polymerase chain reaction designs allowed for global evaluation of interleukin-7 receptor gene expression in whole blood. In the discovery cohort, all interleukin-7 receptor transcripts studied were expressed at lower levels in septic shock patients than in healthy volunteers. Interleukin-7 receptor gene expression at day 3 after septic shock diagnosis was associated with day 28 mortality. Patients at a lower risk of death showed higher expression levels. These results were confirmed in the independent validation cohort. Interestingly, using a threshold obtained on the discovery cohort, we observed in the validation cohort a high negative predictive value for day 28 mortality for the transcript encoding the membrane form of interleukin-7 receptor (0.86; 95% CI, 0.79-0.93). CONCLUSIONS: Interleukin-7 receptor transcripts appear as biomarkers of impaired adaptive immune response in septic shock patients and as a promising tool for patient stratification in clinical trials evaluating immunoadjuvant therapies.

Source of Circulating Pentraxin 3 in Septic Shock Patients.

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.

Assessment of sepsis-induced immunosuppression at ICU discharge and 6 months after ICU discharge.

BACKGROUND: Increase in mortality and in recurrent infections in the year following ICU discharge continues in survivors of septic shock, even after total clinical recovery from the initial septic event and its complications. This supports the hypothesis that sepsis could induce persistent long-term immune dysfunctions. To date, there is almost no data on ICU discharge and long-term evolution of sepsis-induced immunosuppression in septic shock survivors. The aim of this study was to assess the persistence of sepsis-induced immunosuppression by measuring expression of human leukocyte antigen DR on monocytes (mHLA-DR), CD4+ T cells, and regulatory T cells (Treg) at ICU discharge and 6 months after ICU discharge in patients admitted to the ICU for septic shock. METHODS: In this prospective observational study, septic shock survivors with no preexisting immune suppression or treatment interfering with the immune system were included. mHLA-DR, CD4+ T cells, and Treg expression were assessed on day 1-2, 3-4, and 6-8 after ICU admission, at ICU discharge, and 6 months after ICU discharge. RESULTS: A total of 40 patients were enrolled during their ICU stay: 21 males (52.5%) and 19 females, median age 68 years (IQR 58-77), median SOFA score on day 1-2 was 8 (IQR 7-9), and median ICU length of stay was 11 days (IQR 7-24). Among these 40 patients, 33 were studied at ICU discharge and 15 were disposed for blood sampling 6 months after ICU discharge. On day 1-2, mHLA-DR expression was abnormally low for all patients [median 4212 (IQR 2640-6047) AB/C] and remained abnormally low at ICU discharge for 75% of them [median 10,281 (IQR 7719-13,035) AB/C]. On day 3-4, 46% of patients presented CD4+ lymphopenia [median 515 (IQR 343-724) mm-3] versus 34% at ICU discharge [median 642 (IQR 459-846) mm-3]. Among patients with a 6-month blood sample, normal values of mHLA-DR were found for all patients [median 32,616 (IQR 24,918-38,738) AB/C] except for one and only another one presented CD4+ lymphopenia. CONCLUSIONS: While immune alterations persist at ICU discharge, there is, at cellular level, no persistent immune alterations among septic shock survivors analyzed 6 months after ICU discharge.

Bioelectrical impedance analysis for heart failure diagnosis in the ED.

INTRODUCTION: The aim of this study was to evaluate bioimpedance vector analysis (BIVA) for the diagnosis of acute heart failure (AHF) in patients presenting with acute dyspnea to the emergency department (ED). METHODS: Patients with acute dyspnea presenting to the ED were prospectively enrolled. Four parameters were assessed: resistance (R), reactance (Ra), total body water (TBW), and extracellular body water (EBW). Brain natriuretic peptide (BNP) measures and cardiac ultrasound studies were performed in all patients at admission. Patients were classified into AHF and non-AHF groups retrospectively by expert cardiologists. RESULTS: Seventy-seven patients (39 men; age, 68±14years; weight, 79.8±20.6 kg) were included. Of the 4 BIVA parameters, Ra was significantly lower in the AHF compared to non-AHF group (32.7±14.3 vs 45.4±19.7; P<.001). Brain natriuretic peptide levels were significantly higher in the AHF group (1050.3±989 vs 148.7±181.1ng/L; P<.001). Reactance levels were significantly correlated to BNP levels (r=-0.5; P<.001). Patients with different mitral valve Doppler profiles (E/e'≤8, E/e' ≥9 and <15, and E/e'≥15) had significant differences in Ra values (47.9±19.9, 34.7±19.4, and 31.2±11.7, respectively; P=.003). Overall, the sensitivity of BIVA for AHF diagnosis with a Ra cutoff at 39Ω was 67% with a specificity of 76% and an area under the curve at 0.76. However, Ra did not significantly improve the area under the curve of BNP for the diagnosis of AHF (P=not significant). CONCLUSION: In a population of patients presenting to the ED with dyspnea, BIVA was significantly related to the AHF status but did not improve the diagnostic performance for AHF in addition to BNP alone.