Granulocyte-macrophage colony-stimulating factor (GM-CSF) in patients presenting sepsis-induced immunosuppression: The GRID randomized controlled trial.

PURPOSE: Septic shock is associated in some patients with a profound immunosuppression. We hypothesized that GM-CSF would reduce the occurrence of ICU-acquired infections in immunosuppressed septic patients. METHODS: Randomized double-blind trial conducted between 2015 and 2018. Adult patients, admitted to ICU, with severe sepsis or septic shock presenting with sepsis-induced immunosuppression defined by mHLA-DR < 8000 ABC (antibodies bound per cell) at day 3 were included. Patients were randomized to receive GM-CSF 125 µg/m2 or placebo for 5 days at a 1:1 ratio. The primary outcome was the difference in the number of patients presenting≥1 ICU-acquired infection at day 28 or ICU discharge. RESULTS: The study was prematurely stopped because of insufficient recruitment. A total of 98 patients were included, 54 in the intervention group and 44 in the placebo group. The two groups were similar except for a higher body mass index and McCabe score in the intervention group. No significant difference was observed between groups regarding ICU-acquired infection (11% vs 11%, p = 1.000), 28-day mortality (24% vs 27%,p = 0.900), or the number or localization of the ICU infections. CONCLUSION: GM-CSF had no effect on the prevention of ICU-acquired infection in sepsis immunosuppression, but any conclusion is limited by the early termination of the study leading to low number of included patients.

Association between mRNA expression of CD74 and IL10 and risk of ICU-acquired infections: a multicenter cohort study.

PURPOSE: Intensive care unit (ICU)-acquired infections (IAI) result in increased hospital and ICU stay, costs and mortality. To date, no biomarker has shown sufficient evidence and ease of application in clinical routine for the identification of patients at risk of IAI. We evaluated the association of the systemic mRNA expression of two host response biomarkers, CD74 and IL10, with IAI occurrence in a large cohort of ICU patients. METHODS: ICU patients were prospectively enrolled in a multicenter cohort study. Whole blood was collected on the day of admission (D1) and on day 3 (D3) and day 6 (D6) after admission. Patients were screened daily for IAI occurrence and data were censored after IAI diagnosis. mRNA expression levels of biomarkers were measured using RT-qPCR. Fine and Gray competing risk models were used to assess the association between gene expression and IAI occurrence. RESULTS: A total of 725 patients were analyzed. At least one IAI episode occurred in 137 patients (19%). After adjustment for shock and sepsis status at admission, CD74 and IL10 levels were found to be significantly associated with IAI occurrence [subdistribution hazard ratio (95% confidence interval) 0.67 (0.46-0.97) for CD74 D3/D1 expression ratio and 2.21 (1.63-3.00) for IL10 at D3]. IAI cumulative incidence was significantly different between groups stratified according to CD74 or IL10 expression (Gray tests p < 0.001). CONCLUSION: Our results suggest that two immune biomarkers, CD74 and IL10, could be relevant tools for the identification of IAI risk in ICU patients.

Identification of CD177 as the most dysregulated parameter in a microarray study of purified neutrophils from septic shock patients.

Sepsis represents the host's systemic inflammatory response to an infection. In this condition, immune response associates a marked inflammatory response and the delayed development of severe dysfunctions affecting both innate and adaptive responses. As neutrophils are the first line of defense against infection, they are central to the pathophysiology of sepsis in first hours. Nevertheless, their role during immunosuppression phase remains elusive. The main objective of the current work was to perform a transcriptomic study on purified neutrophils from septic shock patients (n=9) so as to identify genes that are differentially expressed during the first week after disease onset both (3-4 and 6-8days) versus healthy donors. Then, 45 septic shock patients were prospectively enrolled to confirm results at the protein level using flow cytometry. Twenty healthy volunteers (HV) were also included for the whole study. By comparing the transcriptome of purified neutrophils, we identified 364 up-regulated and 328 down-regulated genes differentially expressed. Of them, CD177 mRNA, coding for an activation molecule in chemotaxis, had the highest fold change modulation between patients and HV. This increase was then confirmed at the protein level. There was a constant subset of neutrophils that did not express CD177. However, when positive, septic neutrophils presented with significantly increased CD177 expression. Of note, no association between CD177 overexpression and features of immunosuppression has been highlighted. In addition, this up-regulation was negatively correlated with a decreased expression of CD10, a characteristic of immature myeloid cells. In conclusion, in this exploratory work, we shed light on the increased CD177 mRNA and protein expressions in circulating neutrophils after septic shock. Considering the potential dual roles of CD177 neutrophil (i.e., maturation/chemotaxis), negatively correlated in this study, its participation in septic shock pathophysiology deserves further investigation. Furthermore, its potential as a biomarker for sepsis would deserve to be investigated in large cohorts of patients.

Decreased CX3CR1 messenger RNA expression is an independent molecular biomarker of early and late mortality in critically ill patients.

BACKGROUND: Chemokine (C-X3-C motif) receptor 1 (CX3CR1) was identified as the most differentially expressed gene between survivors and non-survivors in two independent cohorts of septic shock patients and was proposed as a marker of sepsis-induced immunosuppression. Whether such a biomarker is associated with mortality in the heterogeneous group of critically ill patients is unknown. The primary objective of this study was to evaluate the association between CX3CR1 messenger RNA (mRNA) expression and mortality in intensive care unit (ICU) patients. The secondary objective was to evaluate similar endpoints in the subgroup of septic shock patients. METHODS: We performed a prospective, multicentre, non-interventional study in six ICUs of university hospitals in Lyon, France. Every consecutive adult patient with systemic inflammatory response syndrome and an expected length of stay in the ICU over 2 days was included. Whole-blood CX3CR1 mRNA expression was measured by quantitative real-time polymerase chain reaction at day 1 (D1) and D3 after inclusion. RESULTS: In ICU patients (n = 725), decreased CX3CR1 mRNA expression at D1 was associated with high D7 mortality (AUC 0.70, adjusted OR [aOR] 2.03, 95 % CI 1.19-3.46), while decreased expression at D3 was associated with increased D28 mortality (AUC 0.64, aOR 2.34, 95 % CI 1.45-3.77). In septic shock patients (n = 279), similar associations were observed between decreased D1 CX3CR1 mRNA expression and D7 mortality (AUC 0.69, aOR 2.76, 95 % CI 1.32-5.75) as well as decreased D3 expression and D28 mortality (AUC 0.72, aOR 3.98, 95 % CI 1.72-9.23). These associations were independent of lactacidaemia, Simplified Acute Physiology Score II, Sepsis-related Organ Failure Assessment score and Charlson comorbidity index. CONCLUSIONS: This study represents the largest evaluation of such an mRNA marker in a heterogeneous cohort of severely injured patients. Our results show that decreased CX3CR1 mRNA expression is associated with increased mortality in ICU patients. This suggests a link between injury-induced immunosuppression and mortality in critically ill patients. In this context, the monitoring of such a host response molecular biomarker could prove very helpful for the identification of patients at high risk of death in the ICU.

Elevated plasmatic level of soluble IL-7 receptor is associated with increased mortality in septic shock patients.

PURPOSE: Adjunctive immunoadjuvant therapies are now proposed in the treatment of septic patients that develop immune dysfunctions. However, a prerequisite is to identify patients at high risk of death that would benefit from such therapy. Knowing that rhIL-7 is a putative candidate for septic shock treatment, we evaluated the association between increased plasmatic level of soluble CD127 (sCD127, IL-7 receptor alpha chain) and mortality after septic shock. METHODS: sCD127 plasmatic level was measured in 70 septic shock patients sampled at day 1-2 (D1) and day 3-4 (D3) after the onset of shock and 41 healthy volunteers. RESULTS: Compared with survivors, non-survivors presented with significantly higher sCD127 concentrations at D1 and D3 (p < 0.001 and p = 0.002). At D1, the area under the receiver operating characteristic curve for sCD127 level association with mortality was 0.846 (p < 0.0001). Kaplan-Meier survival curves illustrated that mortality was significantly different after stratification based on D1 sCD127 level (log rank test, hazard ratio 9.10, p < 0.0001). This association was preserved in multivariate logistic regression analysis including clinical confounders (age, SAPS II and SOFA scores, odds ratio 12.71, p = 0.003). Importantly, patient stratification on both D1 sCD127 value and SAPS II score improved this predictive capacity (log rank test, p = 0.0001). CONCLUSIONS: Increased sCD127 plasmatic level enables the identification of a group of septic shock patients at high risk of death. After confirmation in a larger cohort, this biomarker may be of interest for patient stratification in future clinical trials.

Early and dynamic changes in gene expression in septic shock patients: a genome-wide approach.

BACKGROUND: As early and appropriate care of severe septic patients is associated with better outcome, understanding of the very first events in the disease process is needed. Pan-genomic analyses offer an interesting opportunity to study global genomic response within the very first hours after sepsis. The objective of this study was to investigate the systemic genomic response in severe intensive care unit (ICU) patients and determine whether patterns of gene expression could be associated with clinical severity evaluated by the severity score. METHODS: Twenty-eight ICU patients were enrolled at the onset of septic shock. Blood samples were collected within 30 min and 24 and 48 h after shock and genomic response was evaluated using microarrays. The genome-wide expression pattern of blood leukocytes was sequentially compared to healthy volunteers and after stratification based on Simplified Acute Physiology Score II (SAPSII) score to identify potential mechanisms of dysregulation. RESULTS: Septic shock induces a global reprogramming of the whole leukocyte transcriptome affecting multiple functions and pathways (>71% of the whole genome was modified). Most altered pathways were not significantly different between SAPSII-high and SAPSII-low groups of patients. However, the magnitude and the duration of these alterations were different between these two groups. Importantly, we observed that the more severe patients did not exhibit the strongest modulation. This indicates that some regulation mechanisms leading to recovery seem to take place at the early stage. CONCLUSIONS: In conclusion, both pro- and anti-inflammatory processes, measured at the transcriptomic level, are induced within the very first hours after septic shock. Interestingly, the more severe patients did not exhibit the strongest modulation. This highlights that not only the responses mechanisms by themselves but mainly their early and appropriate regulation are crucial for patient recovery. This reinforces the idea that an immediate and tailored aggressive care of patients, aimed at restoring an appropriately regulated immune response, may have a beneficial impact on the outcome.