Persistent inflammation and immunosuppression: a common syndrome and new horizon for surgical intensive care

Effects of Antithrombin on Persistent Inflammation, Immunosuppression, and Catabolism Syndrome among Patients with Sepsis-Induced Disseminated Intravascular Coagulation

Persistent inflammation, immunosuppression, and catabolism syndrome (PICS) is a serious condition after critical care. We examined the efficacy of antithrombin, which may attenuate coagulopathy with the control of inflammation, for PICS among patients with sepsis-induced disseminated intravascular coagulation (DIC). The present study used the inpatient claims database with laboratory findings to identify patients admitted to intensive care units and diagnosed with sepsis and DIC. A composite of the incidence of PICS on day 14 or 14-day mortality as the primary outcome was compared between the antithrombin and control groups using a propensity-score-matched analysis. Secondary outcomes were the incidence of PICS on day 28, 28-day mortality, and in-hospital mortality. A total of 324 well-balanced matched pairs were generated from 1622 patients. The primary outcome did not differ between the antithrombin and control groups (63.9% vs. 68.2%, respectively, p = 0.245). However, the incidences of 28-day and in-hospital mortality were significantly lower in the antithrombin group (16.0% vs. 23.5% and 24.4% vs. 35.8%, respectively). Similar results were obtained in a sensitivity analysis using overlap weighting. Antithrombin did not reduce the occurrence of PICS on day 14 in patients with sepsis-induced DIC; however, it was associated with a better mid-term (day 28) prognosis.

Muscle stem cells contribute to long-term tissue repletion following surgical sepsis

BACKGROUND

Over the past decade, advances in sepsis identification and management have resulted in decreased sepsis mortality. This increase in survivorship has highlighted a new clinical obstacle: chronic critical illness (CCI), for which there are no effective treatment options. Up to half of sepsis survivors suffer from CCI, which can include multi-organ dysfunction, chronic inflammation, muscle wasting, physical and mental disabilities, and enhanced frailty. These symptoms prevent survivors from returning to regular day-to-day activities and are directly associated with poor quality of life.

METHODS

Mice were subjected to cecal ligation and puncture (CLP) with daily chronic stress (DCS) as an in vivo model to study sepsis late-effects/sequelae on skeletal muscle components. Longitudinal monitoring was performed via magnetic resonance imaging, skeletal muscle and/or muscle stem cell (MuSCs) assays (e.g., post-necropsy wet muscle weights, minimum Feret diameter measurements, in vitro MuSC proliferation and differentiation, number of regenerating myofibres and numbers of Pax7-positive nuclei per myofibre), post-sepsis whole muscle metabolomics and MuSC isolation and high-content transcriptional profiling.

RESULTS

We report several findings supporting the hypothesis that MuSCs/muscle regeneration are critically involved in post-sepsis muscle recovery. First, we show that genetic ablation of muscle stem cells (MuSCs) impairs post-sepsis muscle recovery (maintenance of 5-8% average lean mass loss compared with controls). Second, we observe impaired MuSCs expansion capacity and morphological defects at 26 days post-sepsis compared with control MuSCs (P < 0.001). Third, when subjected to an experimental muscle injury, sepsis-recovered mice exhibited evidence of impaired muscle regeneration compared with non-septic mice receiving the same muscle injury (CLP/DCS injured mean minimum Feret is 92.1% of control injured, P < 0.01). Fourth, we performed a longitudinal RNA sequencing study on MuSCs isolated from post-sepsis mice and found clear transcriptional differences in all post-sepsis samples compared with controls. At Day 28, CLP/DCS mice satellite cells have multiple altered metabolic pathways, such as oxidative phosphorylation, mitochondrial dysfunction, sirtuin signalling and oestrogen receptor signalling, compared with controls (P < 0.001).

CONCLUSIONS

Our data show that MuSCs and muscle regeneration are required for effective post-sepsis muscle recovery and that sepsis triggers morphological, functional, and transcriptional changes in MuSCs. Moving forward, we strive to leverage a more complete understanding of post-sepsis MuSC/regenerative defects to identify and test novel therapies that promote muscle recovery and improve quality of life in sepsis survivors.

Optimal timing of free total rhubarb anthraquinones on immune regulation in rats with severe acute pancreatitis

ETHNOPHARMACOLOGICAL RELEVANCE

Rhubarb is the peeled and dried root of Rheum palmatum L., Rheum tanguticum Maxim. ex Balf. or Rheum officinale Baill. Free total rhubarb anthraquinones (FTRAs) isolated and extracted from rhubarb display the beneficial effects of anti-inflammation and immunological modulation. The timing of immune regulation is a major problem in the immunotherapy for severe acute pancreatitis (SAP). several studies reported that FTRAs could reduce systemic inflammatory responses by inhibiting early immune overactivity in the gut in rats with SAP. But, the optimal timing of rhubarb and FTRAs administration is not clear in clinical practice. Therefore, the time window for the best efficacy of rhubarb and FTRAs in the treatment of SAP patients should be further elucidated.

AIM OF THE STUDY

The main purpose of the present study was to evaluate the efficacy and optimal timing of immune modulation with FTRAs in the treatment of SAP in rats.

MATERIALS AND METHODS

FTRAs (22.5, 45 and 90 mg/kg), Rhubarb (RHU) (900 mg/kg, positive control) or normal saline (vehicle control) were initiated at 0 (immediately), 48 and 72 h every 12 h for three times in total. The therapeutic effects of FTRAs and RHU on pancreas and intestinal tissues injury, secondary infection with pseudomonas aeruginosa (PA), amylase, lipase, D-lactic acid (DLA), endotoxin (ET), proinflammatory and anti-inflammatory cytokines, macrophages, dendritic cells and regulatory T cells (Tregs) in the blood, small intestine and/or mesenteric lymph node (MLN) were determined in rats with SAP after treatment.

RESULTS

The results showed that administration of FTRAs at 0 h was superior to 48 h and 72 h, which significantly protected the injury of pancreas and intestinal tissues, reduced the mortality induced by secondary infection with PA, decreased the levels of amylase, lipase, DLA, ET, tumor necrosis factor α (TNF-α), interleukin 1β (IL-1β), IL-6, IL-8, IL-18 and Tregs, and increased the levels of IL-4, sTNF-αR, macrophages and dendritic cells, secretary immunoglobulin A (SIgA) in the blood and/or small intestinal tissues in rats with SAP.

CONCLUSIONS

In conclusion, our studies indicate that the treatment window of FTRAs for SAP is within 48 h of development, administration of FTRAs at the early stage (0 h, immune overreaction period) was the optimal time and superior to that of 48 h and 72 h for its therapeutic efficacy. The earlier the administration of FTRAs, the better the therapeutic efficacy. Therefore, our data may provide a scientific rationale for the clinical application and optimal timing of FTRAs in the treatment of SAP.

[Pay attention to persistent inflammation-immunosuppression-catabolism syndrome in the late stage of severe burns]

With the deepening of researches on organ complications after severe burns and the continuous improvement of monitoring and support technology for organ function, severe burn patients have avoided death in the early and middle to late stages due to shock, infection, etc., and entered the late stage of burns. Due to the failure of timely and effective burn wound healing and long-term exposure and infection of extensive burn wounds, some of these patients were in chronic and critical conditions such as fever, emaciation, and delayed wound healing that are accompanied by decreased immune function, anemia, and hypoproteinemia, etc. It manifested as persistent inflammation-immunosuppression-catabolism syndrome (PICS), leading to prolonged hospitalization and increased long-term mortality. Based on clinical practice of the author's team in burn treatment, this paper briefly expounds the main causes, clinical characteristics, and prevention methods of PICS in the late stage of severe burns of patients, hoping to attract the attention of peers to PICS in the late stage of severe burns.

[Analysis of the risk factors of persistent inflammation-immunosuppression-catabolism syndrome in patients with extensive burns]

Objective: To investigate the risk factors and treatment outcome of persistent inflammation-immunosuppression-catabolism syndrome (PICS) in patients with extensive burns. Methods: A retrospective case series study was conducted. From January 2017 to December 2021, 220 patients with extensive burns who were admitted to Guangzhou Red Cross Hospital of Jinan University met the inclusion criteria, including 168 males and 52 females, aged 18-84 (43±14) years. According to the occurrence of PICS, the patients were divided into PICS group (84 patients) and non-PICS group (136 patients). The general data such as sex, age, complication of underlying diseases and acute physiology and chronic health evaluation Ⅱ (APACHE Ⅱ) score on admission, sepsis-related organ failure evaluation (SOFA) scores on admission and 14 days post admission, and proportion of patients with mechanical ventilation over 48 h during treatment, special conditions such as total burn area, full-thickness burn area, proportion of patients admitted within 48 h post injury, and exposed deep wound area at the 30th day post injury, outcome indicators such as hospitalization day, total cost of hospital stay, number of surgeries, and death of patients in the 2 groups were collected and analyzed. Data were statistically analyzed with independent sample t test, Mann-Whitney U test, and chi-square test. The multivariate logistic regression analysis was performed on the indicators with statistically significant differences between the two groups except for outcome indicators, and the independent risk factors influencing secondary PICS in patients with extensive burns were screened. Results: The APACHE Ⅱ and SOFA scores on admission, and proportion of patients with mechanical ventilation over 48 h during treatment of patients in PICS group were significantly higher than those in non-PICS group (t=6.78, Z=-4.75, χ2=4.74, respectively, P<0.05). There were no statistically significant differences in the rest of general data of patients between the two groups (P>0.05). The total burn area, full-thickness burn area, and exposed deep wound area at the 30th day post injury in PICS group were significantly greater than those in non-PICS group (t=6.29, Z=-7.25, Z=-8.73, P<0.05), the exposed deep wound areas at the 30th day post injury in PICS group and non-PICS group were respectively 25% (15%, 35%) total body surface area (TBSA) and 8% (0, 13%) TBSA, while the proportion of patients admitted within 48 h post injury was significantly lower than that in non-PICS group (χ2=6.13, P<0.05). The hospitalization day, total cost of hospital stay, and number of surgeries of patients in PICS group were significantly higher than those in non-PICS group (with Z values of -7.12, -8.48, and -6.87, respectively, P<0.05), while the deaths of patients in the 2 groups were similar (P>0.05). The APACHE Ⅱ score on admission and exposed deep wound area at the 30th day post injury both were the independent risk factors for PICS in patients with extensive burns (with odds ratios of 1.15 and 1.07, 95% confidence intervals of 1.06-1.25 and 1.05-1.10, respectively, P<0.05). Conclusions: The APACHE Ⅱ score on admission and exposed deep wound area at the 30th day post injury are the independent risk factors for PICS in patients with extensive burns. The patients with secondary PICS had good prognosis with more surgical intervention and hospitalization day, and higher total cost of hospital stay.

Synbiotics and Surgery: Can Prebiotics and Probiotics Affect Inflammatory Surgical Outcomes?

PURPOSE OF REVIEW

Prebiotics, probiotics, and synbiotics have received increasing attention over the years for their beneficial impact on the gut microbiome and for their systemic anti-inflammatory effects. They have also been shown to improve surgical outcomes. Here, we review the inflammatory effects of surgery as well as the data which suggests a benefit of prebiotics, probiotics, and synbiotics taken in the perioperative period.

RECENT FINDINGS

Synbiotics and fermented foods may have an even greater anti-inflammatory effect than probiotics or prebiotics alone. Recent data suggest that the anti-inflammatory effects and microbiome changes brought on by prebiotics, probiotics, and synbiotics have the potential to improve surgical outcomes. We highlight the potential to alter systemic inflammation, surgical and hospital-acquired infections, colorectal cancer formation, recurrence, and anastomotic leak. Synbiotics could also impact metabolic syndrome. Prebiotics, probiotics, and especially synbiotics may be extremely beneficial when taken in the perioperative period. Even short-term gut microbiome pre-habilitation could alter surgical outcomes significantly.

Comprehensively evaluate the short outcome of small bowel obstruction: A novel medical-economic score system

BACKGROUND

Small bowel obstruction (SBO) still imposes a substantial burden on the health care system. Traditional evaluation systems for SBO outcomes only focus on a single element. The comprehensive evaluation of outcomes for patients with SBO remains poorly studied. Early intensive clinical care would effectively improve the short-term outcomes for SBO, however, the full spectrum of the potential risk status regarding the high complication-cost burden is undetermined.

AIM

We aim to construct a novel system for the evaluation of SBO outcomes and the identification of potential risk status.

METHODS

Patients who were diagnosed with SBO were enrolled and stratified into the simple SBO (SiBO) group and the strangulated SBO (StBO) group. A principal component (PC) analysis was applied for data simplification and the extraction of patient characteristics, followed by separation of the high PC score group and the low PC score group. We identified independent risk status on admission via a binary logistic regression and then constructed predictive models for worsened management outcomes. Receiver operating characteristic curves were drawn, and the areas under the curve (AUCs) were calculated to assess the effectiveness of the predictive models.

RESULTS

Of the 281 patients, 45 patients (16.0%) were found to have StBO, whereas 236 patients (84.0%) had SiBO. Regarding standardized length of stay (LOS), total hospital cost and the presence of severe adverse events (SAEs), a novel principal component was extracted (PC score = 0.429 × LOS + 0.444 × total hospital cost + 0.291 × SAE). In the multivariate analysis, risk statuses related to poor results for SiBO patients, including a low lymphocyte to monocyte ratio (OR = 0.656), radiological features of a lack of small bowel feces signs (OR = 0.316) and mural thickening (OR = 1.338), were identified as risk factors. For the StBO group, higher BUN levels (OR = 1.478) and lower lymphocytes levels (OR = 0.071) were observed. The AUCs of the predictive models for poor outcomes were 0.715 (95%CI: 0.635-0.795) and 0.874 (95%CI: 0.762-0.986) for SiBO and StBO stratification, respectively.

CONCLUSION

The novel PC indicator provided a comprehensive scoring system for evaluating SBO outcomes on the foundation of complication-cost burden. According to the relative risk factors, early tailored intervention would improve the short-term outcomes.

SCIATIC DENERVATION-INDUCED SKELETAL MUSCLE ATROPHY IS ASSOCIATED WITH PERSISTENT INFLAMMATION AND INCREASED MORTALITY DURING SEPSIS

ABSTRACT

Background: Patients with underlying skeletal muscle atrophy are likely to develop aggravated sepsis. However, no study has experimentally verified the association between the prognosis of sepsis and muscle atrophy, and the mechanism of aggravation of sepsis under muscle atrophy remains unclear. In this study, we investigated the effect of skeletal muscle atrophy induced by sciatic denervation (DN), an experimental muscle atrophy model, on sepsis prognosis. Methods: Skeletal muscle atrophy was induced by DN of the sciatic nerve in C57BL/6J male mice. Cecal ligation and puncture (CLP) was performed to induce sepsis. Results: The survival rates of the sham and DN groups 7 days after CLP were 63% and 35%, respectively, wherein an approximately 30% reduction was observed in the DN group ( P < 0.05, vs. sham-CLP). The DN group had a higher bacterial count in the blood 48 h after CLP ( P < 0.05, vs. sham-CLP). Notably, NOx (a metabolite of nitric oxide) concentrations in DN mice were higher than those in sham mice after CLP ( P < 0.05, vs. sham-CLP), whereas serum platelet levels were lower 48 h after CLP ( P < 0.05, vs. sham-CLP). In organ damage analysis, DN mice presented increased protein expression of the kidney injury molecule (KIM-1) and neutrophil gelatinase-associated lipocalin (NGAL), a kidney injury marker, after CLP (NGAL 48 h after CLP, P < 0.05, vs. sham-CLP; KIM-1 24 h after CLP, P < 0.01, vs. sham-CLP). Furthermore, nitro tyrosine levels in the kidneys of DN mice were higher 48 h after CLP compared with those in sham-CLP mice, indicating the accumulation of nitrative stress ( P < 0.05, vs. sham-CLP). Serum cytokine levels were increased in both groups after CLP, but decreased in the sham group 48 h after CLP and remained consistently higher in the DN group (tumor necrosis factor [TNF]-α: P < 0.05, sham-CLP vs. DN-CLP; interleukin (IL)-1β: P < 0.01, sham-CLP vs. DN-CLP; IL-6: P < 0.05, DN vs. DN-CLP; IL-10: P < 0.05, sham-CLP vs. DN-CLP). Conclusions: We verified that skeletal muscle atrophy induced by DN is associated with poor prognosis after CLP-induced sepsis. Importantly, mice with skeletal muscle atrophy presented worsening sepsis prognosis at late onset, including prolonged infection, persistent inflammation, and kidney damage accumulation, resulting in delayed recovery.

Microvesicle-Mediated Transfer of DNA Methyltransferase Proteins Results in Recipient Cell Immunosuppression

INTRODUCTION

Patients with sepsis exhibit significant, persistent immunologic dysfunction. Evidence supports the hypothesis that epigenetic regulation of key cytokines plays an important role in this dysfunction. In sepsis, circulating microvesicles (MVs) containing elevated levels of DNA methyltransferase (DNMT) mRNA cause gene methylation and silencing in recipient cells. We sought to examine the functional role of MV DNMT proteins in this immunologic dysfunction.

METHODS

In total, 33 patients were enrolled within 24 h of sepsis diagnosis (23 sepsis, 10 critically ill controls). Blood and MVs were collected on days 1, 3, and 5 of sepsis, and protein was isolated from the MVs. Levels of DNMT protein and activity were quantified. MVs were produced in vitro by stimulating naïve monocytes with lipopolysaccharide. Methylation was assessed using bisulfate site-specific qualitative real-time polymerase chain reaction.

RESULTS

The size of MVs in the patients with sepsis decreased from days 1 to 5 compared to the control group. Circulating MVs contained significantly higher levels of DNMT 1 and 3A, protein. We recapitulated the production of these DNMT-containing MVs in vitro by treating monocytes with lipopolysaccharide. We found that exposing naïve monocytes to these MVs resulted in increased promoter methylation of tumor necrosis factor alpha.

CONCLUSIONS

An analysis of the isolated MVs revealed higher levels of DNMT proteins in septic patients than those in nonseptic patients. Exposing naïve monocytes to DNMT-containing MVs produced in vitro resulted in hypermethylation of tumor necrosis factor alpha, a key cytokine implicated in postsepsis immunosuppression. These results suggest that DNMT-containing MVs cause epigenetic changes in recipient cells. This study highlights a novel role for MVs in the immune dysfunction of patients with sepsis.

Characterization of Mortality by Sepsis Source in Patients Admitted to the Surgical Intensive Care Unit

INTRODUCTION

The impact of infectious source on sepsis outcomes for surgical patients is unclear. The objective of this study was to evaluate the association between sepsis sources and cumulative 90-d mortality in patients admitted to the surgical intensive care unit (SICU) with sepsis.

METHODS

All patients admitted to the SICU at an academic institution who met sepsis criteria (2014-2019, n = 1296) were retrospectively reviewed. Classification of source was accomplished through a chart review and included respiratory (RT, n = 144), intra-abdominal (IA, n = 859), skin and soft tissue (SST, n = 215), and urologic (UR, n = 78). Demographics, comorbidities, and clinical presentation were compared. Outcomes included 90-d mortality, respiratory and renal failure, length of stay, and discharge disposition. Cox-proportional regression was used to model predictors of mortality; P < 0.05 was significant.

RESULTS

Patients with SST were younger, more likely to be diabetic and obese, but had the lowest total comorbidities. Median admission sequential organ failure assessment scores were highest for IA and STT and lowest in urologic infections. Cumulative 90-d mortality was highest for IA and RT (35% and 33%, respectively) and lowest for SST (20%) and UR (8%) (P < 0.005). Compared to the other categories, UR infections had the lowest SICU length of stay and the highest discharge-to-home (57%, P < 0.0005). Urologic infections remained an independent negative predictor of 90-d mortality (odds ratio 0.14, 95% confidence interval: 0.1-0.4), after controlling for sequential organ failure assessment.

CONCLUSIONS

Urologic infections remained an independent negative predictor of 90-d mortality when compared to other sources of sepsis. Characterization of sepsis source revealed distinct populations and clinical courses, highlighting the importance of understanding different sepsis phenotypes.

NEW INSIGHTS INTO THE PATHOPHYSIOLOGY OF TRAUMA AND HEMORRHAGE

ABSTRACT

Circulatory shock from trauma and hemorrhage remains a clinical challenge with mortality still high within the first hours after impact. It represents a complex disease involving the impairment of a number of physiological systems and organs and the interaction of different pathological mechanisms. Multiple external and patient-specific factors may further modulate and complicate the clinical course. Recently, novel targets and models with complex multiscale interaction of data from different sources have been identified which offer new windows of opportunity. Future works needs to consider patient-specific conditions and outcomes to mount shock research onto the next higher level of precision and personalized medicine.

MicroRNA Profiles in Intestinal Epithelial Cells in a Mouse Model of Sepsis

Sepsis is a systemic inflammatory disorder that leads to the dysfunction of multiple organs. In the intestine, the deregulation of the epithelial barrier contributes to the development of sepsis by triggering continuous exposure to harmful factors. However, sepsis-induced epigenetic changes in gene-regulation networks within intestinal epithelial cells (IECs) remain unexplored. In this study, we analyzed the expression profile of microRNAs (miRNAs) in IECs isolated from a mouse model of sepsis generated via cecal slurry injection. Among 239 miRNAs, 14 miRNAs were upregulated, and 9 miRNAs were downregulated in the IECs by sepsis. Upregulated miRNAs in IECs from septic mice, particularly miR-149-5p, miR-466q, miR-495, and miR-511-3p, were seen to exhibit complex and global effects on gene regulation networks. Interestingly, miR-511-3p has emerged as a diagnostic marker in this sepsis model due to its increase in blood in addition to IECs. As expected, mRNAs in the IECs were remarkably altered by sepsis; specifically, 2248 mRNAs were decreased, while 612 mRNAs were increased. This quantitative bias may be possibly derived, at least partly, from the direct effects of the sepsis-increased miRNAs on the comprehensive expression of mRNAs. Thus, current in silico data indicate that there are dynamic regulatory responses of miRNAs to sepsis in IECs. In addition, the miRNAs that were increased with sepsis had enriched downstream pathways including Wnt signaling, which is associated with wound healing, and FGF/FGFR signaling, which has been linked to chronic inflammation and fibrosis. These modifications in miRNA networks in IECs may lead to both pro- and anti-inflammatory effects in sepsis. The four miRNAs discovered above were shown to putatively target LOX, PTCH1, COL22A1, FOXO1, or HMGA2, via in silico analysis, which were associated with Wnt or inflammatory pathways and selected for further study. The expressions of these target genes were downregulated in sepsis IECs, possibly through posttranscriptional modifications of these miRNAs. Taken together, our study suggests that IECs display a distinctive miRNA profile which is capable of comprehensively and functionally reshaping the IEC-specific mRNA landscape in a sepsis model.

Inhibition of DDX3X alleviates persistent inflammation, immune suppression and catabolism syndrome in a septic mice model

OBJECTIVE

DDX3X is involved in various pathological processes such as infection, immunity and cell death. This study aimed to investigate the effect of RK-33, a specific inhibitor of DDX3X, on the progression of sepsis to persistent inflammation, immune suppression and catabolism syndrome(PICS).

METHODS

The septic mice model was established using caecal ligation and perforation (CLP). The mice were randomly divided into four groups: sham group, sham + RK-33 group (20 mg/kg, intraperitoneal injection, once a day), CLP group and CLP + RK-33 group (20 mg/kg, intraperitoneal injection, once a day). The number of inflammatory cells in the peripheral blood, spleen and bone marrow was calculated, and inflammatory cytokines were detected using an enzyme-linked immunosorbent assay. The septic mice's body weight and skeletal muscle mass were measured, and skeletal muscle tissues were examined using eosin staining. Western blotting was performed to detect the expression levels of MuRF1, atrogin1 and NLRP3 in the skeletal muscle of septic mice. Additionally, reactive oxidative species, superoxide dismutase and malondialdehyde were measured using commercial kits.

RESULTS

RK-33 reduced inflammatory cell counts and cytokine levels in CLP mice, ameliorated the decline in CD4 and CD8 T cells and prevented the loss of body weight and skeletal muscle mass in septic mice. Additionally, RX-33 reduced oxidative stress in the skeletal muscle of septic mice.

CONCLUSION

In the established sepsis mouse model, RK-33 alleviated inflammation and oxidative stress, ameliorated CLP-induced immunosuppression and skeletal muscle atrophy and improved survival. These findings suggest that RK-33 could be a novel potential therapeutic agent for preventing the progression of sepsis to PICS.

Relationship among Low T3 Levels, Type 3 Deiodinase, Oxidative Stress, and Mortality in Sepsis and Septic Shock: Defining Patient Outcomes

Low T3 syndrome occurs frequently in patients with sepsis. Type 3 deiodinase (DIO3) is present in immune cells, but there is no description of its presence in patients with sepsis. Here, we aimed to determine the prognostic impact of thyroid hormones levels (TH), measured on ICU admission, on mortality and evolution to chronic critical illness (CCI) and the presence of DIO3 in white cells. We used a prospective cohort study with a follow-up for 28 days or deceased. Low T3 levels at admission were present in 86.5% of the patients. DIO3 was induced by 55% of blood immune cells. The cutoff value of 60 pg/mL for T3 displayed a sensitivity of 81% and specificity of 64% for predicting death, with an odds ratio of 4.89. Lower T3 yielded an area under the receiver operating characteristic curve of 0.76 for mortality and 0.75 for evolution to CCI, thus displaying better performance than commonly used prognostic scores. The high expression of DIO3 in white cells provides a novel mechanism to explain the reduction in T3 levels in sepsis patients. Further, low T3 levels independently predict progression to CCI and mortality within 28 days for sepsis and septic shock patients.

Utility of monocyte HLA-DR and rationale for therapeutic GM-CSF in sepsis immunoparalysis

Sepsis, a heterogeneous clinical syndrome, features a systemic inflammatory response to tissue injury or infection, followed by a state of reduced immune responsiveness. Measurable alterations occur in both the innate and adaptive immune systems. Immunoparalysis, an immunosuppressed state, associates with worsened outcomes, including multiple organ dysfunction syndrome, secondary infections, and increased mortality. Multiple immune markers to identify sepsis immunoparalysis have been proposed, and some might offer clinical utility. Sepsis immunoparalysis is characterized by reduced lymphocyte numbers and downregulation of class II human leukocyte antigens (HLA) on innate immune monocytes. Class II HLA proteins present peptide antigens for recognition by and activation of antigen-specific T lymphocytes. One monocyte class II protein, mHLA-DR, can be measured by flow cytometry. Downregulated mHLA-DR indicates reduced monocyte responsiveness, as measured by ex-vivo cytokine production in response to endotoxin stimulation. Our literature survey reveals low mHLA-DR expression on peripheral blood monocytes correlates with increased risks for infection and death. For mHLA-DR, 15,000 antibodies/cell appears clinically acceptable as the lower limit of immunocompetence. Values less than 15,000 antibodies/cell are correlated with sepsis severity; and values at or less than 8000 antibodies/cell are identified as severe immunoparalysis. Several experimental immunotherapies have been evaluated for reversal of sepsis immunoparalysis. In particular, sargramostim, a recombinant human granulocyte-macrophage colony-stimulating factor (rhu GM-CSF), has demonstrated clinical benefit by reducing hospitalization duration and lowering secondary infection risk. Lowered infection risk correlates with increased mHLA-DR expression on peripheral blood monocytes in these patients. Although mHLA-DR has shown promising utility for identifying sepsis immunoparalysis, absence of a standardized, analytically validated method has thus far prevented widespread adoption. A clinically useful approach for patient inclusion and identification of clinically correlated output parameters could address the persistent high unmet medical need for effective targeted therapies in sepsis.

Improvement of inflammatory response and gastrointestinal function in perioperative of cholelithiasis by Modified Xiao-Cheng-Qi decoction

BACKGROUND

In the perioperative period of biliary surgery, various factors can induce the release of a large number of inflammatory factors, leading to an imbalance in pro-inflammatory and anti-inflammatory responses and resulting in gastrointestinal (GI) dysfunction. Enhanced Recovery After Surgery protocols in biliary surgery have been shown to reduce the stress response and accelerate postoperative recovery. It is crucial to reduce the inflammatory response and promote the recovery of GI function after biliary surgery, both of which are the basis and key for perioperative care and postoperative recovery.

AIM

To better understand the effects of Modified Xiao-Cheng-Qi decoction (MXD) on inflammatory response and GI function in the perioperative management of cholelithiasis and their correlation.

METHODS

This was a prospective randomized placebo-controlled trial, in which 162 patients who received biliary tract surgery were randomly assigned to three groups: MXD group, XD group, and placebo-control group. The observed parameters included frequency of bowel sounds, time of first flatus and defecation, time of diet, and amount of activity after surgery. The serum levels of C-reactive protein (CRP), interleukin (IL)-6, IL-10, serum amyloid A protein (SAA), and substance P were measured by the enzyme-linked immunosorbent assay. Then, the spearman correlation coefficient was used to analyze the relationship between the indicators of GI function and inflammation.

RESULTS

Compared to the placebo-control, improvements in GI function were observed in the MXD groups including reduced incidence of nausea, vomiting, and bloating; and earlier first exhaust time, first defecation time, and feeding time after surgery (P < 0.05). On the 1^st and 2^nd d after surgery, IL-6, CRP and SAA levels in MXD group were lower than that in placebo control, but substance P level was higher, compared to the control (P < 0.05). Functional diarrhea occurred in both MXD and XD groups without any other adverse effects, toxic reactions, and allergic reactions. Diarrhea was relieved after the discontinuation of the investigational remedies. Bowel sounds at 12 h after surgery, the occurring time of the first flatus, first defecation, postoperative liquid diet and semi-liquid diet were significantly correlated with levels of IL-6, CRP, SAA and substance P on second day after surgery (P < 0.05).

CONCLUSION

Treatment with MXD can relieve inflammatory response and improve GI function after surgery. Moreover, there are significant correlations between them. Furthermore, it does not cause serious adverse reactions.

Persistent inflammation-immunosuppression-catabolism syndrome in patients with systemic lupus erythematosus

OBJECTIVE

To evaluate the clinical characteristics and prognosis of systemic lupus erythematosus (SLE) with persistent inflammation-immunosuppression-catabolism syndrome (PICS).

METHODS

We retrospectively analyzed patients with SLE who were admitted to the renal intensive care unit (ICU) for over 14 days at Jinling Hospital from July 2010 to July 2018. According to the diagnostic criteria of PICS, we divided the SLE patients into a PICS group and a non-PICS group. We performed a multivariate Cox regression analysis on the risk factors for death in these two groups by comparing the clinical features and prognosis.

RESULTS

A total of 96 SLE patients met the inclusion and exclusion criteria of this study, including 61 patients in the PICS group and 35 patients in the non-PICS group. The PICS group patients required a longer length of stay in ICU with higher inflammatory indicators (such as C-reactive protein, procalcitonin and interleukin-6) and lower immune levels (such as total, CD3 + , CD4 + , CD8 + and CD20 + lymphocytes) compared to the non-PICS group patients (P < 0.01). Hemoglobin, platelets, serum creatinine, serum blood urea nitrogen and SLE Disease Activity Index (SLE-DAI) score in the PICS group were lower than those in the non-PICS group (P < 0.05), suggesting severe hematological injury in the PICS group and relatively severe renal damage in the non-PICS group. The rates of PICS combined with sepsis, acute respiratory distress syndrome, mechanical ventilation, gram-positive bacteria, gram-negative bacteria, fungi and double infections were higher than those in the non-PICS group (P < 0.05). The 3-year survival rate was 50.82% in the PICS group and 85.71% in the non-PICS group. The 3-year renal survival rate was 32.79% in the PICS group and 51.43% in the non-PICS group. Multivariate Cox regression found that the total lymphocyte count during ICU admission was an independent risk factor for death in SLE patients with PICS.

CONCLUSION

Patients with SLE complicated with PICS had longer ICU stays, a lower level of SLE activity, a higher risk of secondary infection and a significantly lower survival rate than non-PICS patients.

Immunopathology of terminal complement activation and complement C5 blockade creating a pro-survival and organ-protective phenotype in trauma

BACKGROUND AND PURPOSE

Traumatic haemorrhage (TH) is the leading cause of potentially preventable deaths that occur during the prehospital phase of care. No effective pharmacological therapeutics are available for critical TH patients yet. Here, we identify terminal complement activation (TCA) as a therapeutic target in combat casualties and evaluate the efficacy of a TCA inhibitor (nomacopan) on organ damage and survival in vivo.

EXPERIMENTAL APPROACH

Complement activation products and cytokines were analysed in plasma from 54 combat casualties. The correlations between activated complement pathway(s) and the clinical outcomes in trauma patients were assessed. Nomacopan was administered to rats subjected to lethal TH (blast injury and haemorrhagic shock). Effects of nomacopan on TH were determined using survival rate, organ damage, physiological parameters, and laboratory profiles.

KEY RESULTS

Early TCA was associated with systemic inflammatory responses and clinical outcomes in this trauma cohort. Lethal TH in the untreated rats induced early TCA that correlated with the severity of tissue damage and mortality. The addition of nomacopan to a damage-control resuscitation (DCR) protocol significantly inhibited TCA, decreased local and systemic inflammatory responses, improved haemodynamics and metabolism, attenuated tissue and organ damage, and increased survival.

CONCLUSION AND IMPLICATIONS

Previous findings of our and other groups revealed that early TCA represents a rational therapeutic target for trauma patients. Nomacopan as a pro-survival and organ-protective drug, could emerge as a promising adjunct to DCR that may significantly reduce the morbidity and mortality in severe TH patients while awaiting transport to critical care facilities.

Akkermansia muciniphila Alleviates Persistent Inflammation, Immunosuppression, and Catabolism Syndrome in Mice

Many patients in intensive care units, especially the elderly, suffer from chronic critical illness and exhibit a new pathophysiological phenotype: persistent inflammation, immunosuppression, and catabolism syndrome (PICS). Most patients with PICS have a constellation of digestive-system symptoms and gut failure. Akkermansia muciniphila (Akk) is a commensal gut bacterium that reduces inflammation, balances immune responses, modulates energy metabolism, and supports gut health. This study investigated the protective effects and underlying mechanisms of live and pasteurized Akk in treating PICS in a mouse model. PICS was induced on day 14 after performing cecal ligation and puncture (CLP) on day 1 and administrating lipopolysaccharide on day 11. Pasteurized or live Akk, or phosphate-buffered saline was administered twice daily by oral gavage for 7 days. Both live and pasteurized Akk attenuated PICS, as evidenced by reduced weight loss, and a reduction in symptoms and serum cytokine/chemokine levels. Liver and intestinal injuries were mitigated, and intestinal barrier integrity improved with Akk administration. Analysis of 16S rRNA amplicon sequences showed that Akk induced significant intestinal microbiota alterations, including increased abundance of Akk, Muribaculaceae, Parabacterbides goldsteinii, and decreased abundance of Escherichia_Shigella and Enterobacteriaceae. Collectively, Akk alleviates PICS by enhancing gut barrier function and reshaped the microbial community.

Activated regulatory T-cells promote duodenal bacterial translocation into necrotic areas in severe acute pancreatitis

OBJECTIVE

In acute pancreatitis (AP), bacterial translocation and subsequent infection of pancreatic necrosis are the main risk factors for severe disease and late death. Understanding how immunological host defence mechanisms fail to protect the intestinal barrier is of great importance in reducing the mortality risk of the disease. Here, we studied the role of the T_reg/Th17 balance for maintaining the intestinal barrier function in a mouse model of severe AP.

DESIGN

AP was induced by partial duct ligation in C57Bl/6 or DEREG mice, in which regulatory T-cells (T_reg) were depleted by intraperitoneal injection of diphtheria toxin. By flow cytometry, functional suppression assays and transcriptional profiling we analysed T_reg activation and characterised T-cells of the lamina propria as well as intraepithelial lymphocytes (IELs) regarding their activation and differentiation. Microbiota composition was examined in intestinal samples as well as in murine and human pancreatic necrosis by 16S rRNA gene sequencing.

RESULTS

The prophylactic T_reg-depletion enhanced the proinflammatory response in an experimental mouse model of AP but stabilised the intestinal immunological barrier function of Th17 cells and CD8⁺/γδTCR⁺ IELs. T_reg depleted animals developed less bacterial translocation to the pancreas. Duodenal overgrowth of the facultative pathogenic taxa Escherichia/Shigella which associates with severe disease and infected necrosis was diminished in T_reg depleted animals.

CONCLUSION

T_regs play a crucial role in the counterbalance against systemic inflammatory response syndrome. In AP, T_reg-activation disturbs the duodenal barrier function and permits translocation of commensal bacteria into pancreatic necrosis. Targeting T_regs in AP may help to ameliorate the disease course.

CLINICAL AND PROGNOSTIC FEATURES OF CHRONIC CRITICAL ILLNESS/PERSISTENT INFLAMMATION IMMUNOSUPPRESSION AND CATABOLISM PATIENTS: A PROSPECTIVE OBSERVATIONAL CLINICAL STUDY

ABSTRACT

Objective: The aims of this study were to investigate and compare the clinical features and prognosis of chronic critical illness (CCI)/persistent inflammation immunosuppression and catabolism (PICS). Methods: This is a prospective observational clinical study. During this study period, we collect intensive care unit patients' data from Suzhou Municipal Hospital and Suzhou Ninth People's Hospital. All patients older than 18 years were included, and according to the corresponding exclusion and diagnostic criteria, they were divided into four groups: PICS group, CCI group, CCI and PICS group (CCI + PICS), and neither CCI nor PICS group (NCCI + NPICS) and collected and recorded age, sex, hospital time, hospital diagnosis, Acute Physiology and Chronic Health Evaluation II score, Sequential Organ Failure Assessment score, C-reactive protein, absolute value lymphocyte count, serum albumin, white blood cell count, absolute value neutrophil count, secondary infection, and 28-day case fatality rate separately. Results: A total of 687 patients were admitted to the intensive care unit during the study period. The hospitalization time less than 14 days were excluded, and 168 patients were eventually included. There are 17 in the PICS group, 71 in the CCI group, 50 in the CCI + PICS group, and 30 in the NCCI + NPICS group. Baseline characteristics showed statistically significant differences in Sequential Organ Failure Assessment, length of hospital stay, and 28-day mortality among four groups. Baseline main indicator and multiple comparisons showed that the CCI + PICS group had longer hospital stay, worse prognosis, and more adverse outcomes. Multivariate analysis showed that final age, C-reactive protein on days 14 and 21, and serum albumin on days 1 and 21 had an impact on the prognosis ( P < 0.05). Conclusion: The clinical prognosis of the four groups decreased in order of NCCI + NPICS, CCI, PICS, and CCI + PICS. Our finding of clinically isolated PICS may indicate that PICS acts as an inducement or independent factor to worsen the prognosis of CCI.

Monitoring of the Forgotten Immune System during Critical Illness-A Narrative Review

Immune organ failure is frequent in critical illness independent of its cause and has been acknowledged for a long time. Most patients admitted to the ICU, whether featuring infection, trauma, or other tissue injury, have high levels of alarmins expression in tissues or systemically which then activate innate and adaptive responses. Although necessary, this response is frequently maladaptive and leads to organ dysfunction. In addition, the counter-response aiming to restore homeostasis and repair injury can also be detrimental and contribute to persistent chronic illness. Despite intensive research on this topic in the last 40 years, the immune system is not routinely monitored in critical care units. In this narrative review we will first discuss the inflammatory response after acute illness and the players of maladaptive response, focusing on neutrophils, monocytes, and T cells. We will then go through commonly used biomarkers, like C-reactive protein, procalcitonin and pancreatic stone protein (PSP) and what they monitor. Next, we will discuss the strengths and limitations of flow cytometry and related techniques as an essential tool for more in-depth immune monitoring and end with a presentation of the most promising cell associated markers, namely HLA-DR expression on monocytes, neutrophil expression of CD64 and PD-1 expression on T cells. In sum, immune monitoring critically ill patients is a forgotten and missing piece in the monitoring capacity of intensive care units. New technology, including bed-side equipment and in deep cell phenotyping using emerging multiplexing techniques will likely allow the definition of endotypes and a more personalized care in the future.

Identification of novel immune-related targets mediating disease progression in acute pancreatitis

Introduction

Acute pancreatitis (AP) is an inflammatory disease with very poor outcomes. However, the order of induction and coordinated interactions of systemic inflammatory response syndrome (SIRS) and compensatory anti-inflammatory response syndrome (CARS) and the potential mechanisms in AP are still unclear.

Methods

An integrative analysis was performed based on transcripts of blood from patients with different severity levels of AP (GSE194331), as well as impaired lung (GSE151572), liver (GSE151927) and pancreas (GSE65146) samples from an AP experimental model to identify inflammatory signals and immune response-associated susceptibility genes. An AP animal model was established in wild-type (WT) mice and Tlr2-deficient mice by repeated intraperitoneal injection of cerulein. Serum lipase and amylase, pancreas impairment and neutrophil infiltration were evaluated to assess the effects of Tlr2 in vivo.

Results

The numbers of anti-inflammatory response-related cells, such as M2 macrophages (P = 3.2 × 10^-3), were increased with worsening AP progression, while the numbers of pro-inflammatory response-related cells, such as neutrophils (P = 3.0 × 10^-8), also increased. Then, 10 immune-related AP susceptibility genes (SOSC3, ITGAM, CAMP, FPR1, IL1R1, TLR2, S100A8/9, HK3 and MMP9) were identified. Finally, compared with WT mice, Tlr2-deficient mice exhibited not only significantly reduced serum lipase and amylase levels after cerulein induction but also alleviated pancreatic inflammation and neutrophil accumulation.

Discussion

In summary, we discovered SIRS and CARS were stimulated in parallel, not activated consecutively. In addition, among the novel susceptibility genes, TLR2might be a novel therapeutic target that mediates dysregulation of inflammatory responses during AP progression.

Investigating the potential of a prematurely aged immune phenotype in severely injured patients as predictor of risk of sepsis

BACKGROUND

Traumatic injury elicits a hyperinflammatory response and remodelling of the immune system leading to immuneparesis. This study aimed to evaluate whether traumatic injury results in a state of prematurely aged immune phenotype to relate this to clinical outcomes and a greater risk of developing additional morbidities post-injury.

METHODS AND FINDINGS

Blood samples were collected from 57 critically injured patients with a mean Injury Severity Score (ISS) of 26 (range 15-75 years), mean age of 39.67 years (range 20-84 years), and 80.7% males, at days 3, 14, 28 and 60 post-hospital admission. 55 healthy controls (HC), mean age 40.57 years (range 20-85 years), 89.7% males were also recruited. The phenotype and frequency of adaptive immune cells were used to calculate the IMM-AGE score, an indicator of the degree of phenotypic ageing of the immune system. IMM-AGE was elevated in trauma patients at an early timepoint (day 3) in comparison with healthy controls (p < 0.001), driven by an increase in senescent CD8 T cells (p < 0.0001), memory CD8 T cells (p < 0.0001) and regulatory T cells (p < 0.0001) and a reduction in naïve CD8 T cells (p < 0.001) and overall T cell lymphopenia (p < 0 .0001). These changes persisted to day 60. Furthermore, the IMM-AGE scores were significantly higher in trauma patients (mean score 0.72) that developed sepsis (p = 0.05) in comparison with those (mean score 0.61) that did not.

CONCLUSIONS

The profoundly altered peripheral adaptive immune compartment after critical injury can be used as a potential biomarker to identify individuals at a high risk of developing sepsis and this state of prematurely aged immune phenotype in biologically young individuals persists for up to two months post-hospitalisation, compromising the host immune response to infections. Reversing this aged immune system is likely to have a beneficial impact on short- and longer-term outcomes of trauma survivors.

Multidimensional machine learning models predicting outcomes after trauma

BACKGROUND

An emerging body of literature supports the role of individualized prognostic tools to guide the management of patients after trauma. The aim of this study was to develop advanced modeling tools from multidimensional data sources, including immunological analytes and clinical and administrative data, to predict outcomes in trauma patients.

METHODS

This was a prospective study of trauma patients at Level 1 centers from 2015 to 2019. Clinical, flow cytometry, and serum cytokine data were collected within 48 hours of admission. Sparse logistic regression models were developed, jointly selecting predictors and estimating the risk of ventilator-associated pneumonia, acute kidney injury, complicated disposition (death, rehabilitation, or nursing facility), and return to the operating room. Model parameters (regularization controlling model sparsity) and performance estimation were obtained via nested leave-one-out cross-validation.

RESULTS

A total of 179 patients were included. The incidences of ventilator-associated pneumonia, acute kidney injury, complicated disposition, and return to the operating room were 17.7%, 28.8%, 22.5%, and 12.3%, respectively. Regarding extensive resource use, 30.7% of patients had prolonged intensive care unit stay, 73.2% had prolonged length of stay, and 23.5% had need for prolonged ventilatory support. The models were developed and cross-validated for ventilator-associated pneumonia, acute kidney injury, complicated dispositions, and return to the operating room, yielding predictive areas under the curve from 0.70 to 0.91. Each model derived its optimal predictive value by combining clinical, administrative, and immunological analyte data.

CONCLUSION

Clinical, immunological, and administrative data can be combined to predict post-traumatic outcomes and resource use. Multidimensional machine learning modeling can identify trauma patients with complicated clinical trajectories and high resource needs.

Immunopathology of chronic critical illness in sepsis survivors: Role of abnormal myelopoiesis

Sepsis remains the single most common cause of mortality and morbidity in hospitalized patients requiring intensive care. Although earlier detection and improved treatment bundles have reduced in-hospital mortality, long-term recovery remains dismal. Sepsis survivors who experience chronic critical illness often demonstrate persistent inflammation, immune suppression, lean tissue wasting, and physical and functional cognitive declines, which often last in excess of 1 year. Older patients and those with preexisting comorbidities may never fully recover and have increased mortality compared with individuals who restore their immunologic homeostasis. Many of these responses are shared with individuals with advanced cancer, active autoimmune diseases, chronic obstructive pulmonary disease, and chronic renal disease. Here, we propose that this resulting immunologic endotype is secondary to a persistent maladaptive reprioritization of myelopoiesis and pathologic activation of myeloid cells. Driven in part by the continuing release of endogenous alarmins from chronic organ injury and muscle wasting, as well as by secondary opportunistic infections, ongoing myelopoiesis at the expense of lymphopoiesis and erythropoiesis leads to anemia, recurring infections, and lean tissue wasting. Early recognition and intervention are required to interrupt this pathologic activation of myeloid populations.

Overview of the Medical Management of the Critically Ill Patient

The medical management of the critically ill patient focuses predominantly on treatment of the underlying condition (e g, sepsis or respiratory failure). However, in the past decade, the importance of initiating early prophylactic treatment for complications arising from care in the intensive care unit setting has become increasingly apparent. As survival from critical illness has improved, there is an increased prevalence of postintensive care syndrome-defined as a decline in physical, cognitive, or psychologic function among survivors of critical illness. The Intensive Care Unit Liberation Bundle, a major initiative of the Society of Critical Care Medicine, is centered on facilitating the return to normal function as early as possible, with the intent of minimizing iatrogenic harm during necessary critical care. These concepts are universally applicable to patients seen by nephrologists in the intensive care unit and may have particular relevance for patients with kidney failure either on dialysis or after kidney transplant. In this article, we will briefly summarize some known organ-based consequences associated with critical illness, review the components of the ABCDEF bundle (the conceptual framework for Intensive Care Unit Liberation), highlight the role nephrologists can play in implementing and complying with the ABCDEF bundle, and briefly discuss areas for additional research.

Surgical Site Infection in Cardiac Surgery

Surgical site infections (SSIs) are one of the most significant complications in surgical patients and are strongly associated with poorer prognosis. Due to their aggressive character, cardiac surgical procedures carry a particular high risk of postoperative infection, with infection incidence rates ranging from a reported 3.5% and 26.8% in cardiac surgery patients. Given the specific nature of cardiac surgical procedures, sternal wound and graft harvesting site infections are the most common SSIs. Undoubtedly, DSWIs, including mediastinitis, in cardiac surgery patients remain a significant clinical problem as they are associated with increased hospital stay, substantial medical costs and high mortality, ranging from 3% to 20%. In SSI prevention, it is important to implement procedures reducing preoperative risk factors, such as: obesity, hypoalbuminemia, abnormal glucose levels, smoking and S. aureus carriage. For decolonisation of S. aureus carriers prior to cardiac surgery, it is recommended to administer nasal mupirocin, together with baths using chlorhexidine-based agents. Perioperative management also involves antibiotic prophylaxis, surgical site preparation, topical antibiotic administration and the maintenance of normal glucose levels. SSI treatment involves surgical intervention, NPWT application and antibiotic therapy.

Decay-Accelerating Factor Creates an Organ-Protective Phenotype after Hemorrhage in Conscious Rats

Preclinical and clinical studies have shown that traumatic hemorrhage (TH) induces early complement cascade activation, leading to inflammation-associated multiple-organ dysfunction syndrome (MODS). Several previous studies have demonstrated the beneficial effects of complement inhibition in anesthetized (unconscious) animal models of hemorrhage. Anesthetic agents profoundly affect the immune response, microcirculation response, and coagulation patterns and thereby may confound the TH research data acquired. However, no studies have addressed the effect of complement inhibition on inflammation-driven MODS in a conscious model of hemorrhage. This study investigated whether early administration of decay-accelerating factor (CD55/DAF, a complement C3/C5 inhibitor) alleviates hemorrhage-induced organ damage and how DAF modulates hemorrhage-induced organ damage. DAF was administered to unanesthetized male Sprague Dawley rats subjected to pressure-controlled hemorrhage followed by a prolonged (4 h) hypotensive resuscitation with or without lactated Ringer’s (LR). We assessed DAF effects on organ protection, tissue levels of complement synthesis and activation, T lymphocyte infiltration, fluid resuscitation requirements, and metabolic acidosis. Hemorrhage with (HR) or without (H) LR resuscitation resulted in significantly increased C3, C5a, and C5b-9 deposition in the lung and intestinal tissues. HR rats had significantly higher tissue levels of complement activation/deposition (particularly C5a and C5b-9 in the lung tissues), a higher but not significant amount of C3 and C5b-9 pulmonary microvascular deposition, and relatively severe injury in the lung and intestinal tissues compared to H rats. DAF treatment significantly reduced tissue C5b-9 formation and C3 deposition in the H or HR rats and decreased tissue levels of C5a and C3 mRNA in the HR rats. This treatment prevented the injury of these organs, improved metabolic acidosis, reduced fluid resuscitation requirements, and decreased T-cell infiltration in lung tissues. These findings suggest that DAF has the potential as an organ-protective adjuvant treatment for TH during prolonged damage control resuscitation.

LIPOPOLYSACCHARIDE-PRECONDITIONED MESENCHYMAL STEM CELL TRANSPLANTATION ATTENUATES CRITICAL PERSISTENT INFLAMMATION IMMUNE SUPPRESSION AND CATABOLISM SYNDROME IN MICE

ABSTRACT

Background: Persistent inflammation, immunosuppression, and catabolism syndrome (PIICS) is associated with high mortality and high health care costs, and there is currently no effective target treatment. Mesenchymal stem cells (MSCs) possess multipotent immunomodulatory properties. LPS-preconditioned type 1 MSCs (MSC1s) are potentially beneficial for PIICS treatment because of their proinflammatory, anti-infective, and healing properties. Here, we investigated the therapeutic efficacy and mechanisms of action of MSC1s in PIICS. Methods: We previously optimized a reaggravated PIICS mouse model, which was used in this study. PIICS mice were subjected to cecal ligation and puncture on day 1 and LPS injection on day 11. Subsequently, the mice were treated with or without MSC1s. Animal survival and phenotypes, along with the levels of catabolism, inflammation, and immunosuppression, were evaluated. MSC1s were cocultured with CD8 + T cells in vitro , and inflammatory cytokine levels and CD8 + T-cell function were assessed. Results: MSC1 transplantation alleviated weight loss and muscle wasting, inhibited catabolism and inflammation, and considerably improved the proportion and function of CD8 + T cells in the PIICS mice. After coculture with MSC1s, the expression levels of CD107a and interferon γ increased, whereas the expression level of programmed death 1 decreased significantly in CD8 + T cells. MSC1s also promoted proinflammatory cytokine secretion and reduced the concentration of soluble PD-L1 in vitro . Conclusions: MSC1s can protect mice against critical PIICS, partly by enhancing CD8 + T-cell function. Therefore, MSC1 transplantation is a novel therapeutic candidate for PIICS.

Traumatized triad of complementopathy, endotheliopathy, and coagulopathy ˗ Impact on clinical outcomes in severe polytrauma patients

Complementopathy, endotheliopathy, and coagulopathy following a traumatic injury are key pathophysiological mechanisms potentially associated with multiple-organ failure (MOF) and mortality. However, the heterogeneity in the responses of complementopathy, endotheliopathy, and coagulopathy to trauma, the nature and extent of their interplay, and their relationship to clinical outcomes remain unclear. Fifty-four poly-trauma patients were enrolled and divided into three subgroups based on their ISS. Biomarkers in blood plasma reflecting complement activation, endothelial damage, and coagulopathy were measured starting from admission to the emergency department and at 3, 6, 12, 24, and 120 hours after admission. Comparative analyses showed that severely injured patients (ISS>24) were associated with longer days on mechanical ventilation, in the intensive care unit and hospital stays, and a higher incidence of hyperglycemia, bacteremia, respiratory failure and pneumonia compared to mildly (ISS<16) or moderately (ISS=16-24) injured patients. In this trauma cohort, complement was activated early, primarily through the alternative complement pathway. As measured in blood plasma, severely injured patients had significantly higher levels of complement activation products (C3a, C5a, C5b-9, and Bb), endothelial damage markers (syndecan-1, sTM, sVEGFr1, and hcDNA), and fibrinolytic markers (D-dimer and LY30) compared to less severely injured patients. Severely injured patients also had significantly lower thrombin generation (ETP and peak) and lower levels of coagulation factors (I, V, VIII, IX, protein C) than less severely injured patients. Complement activation correlated with endothelial damage and hypocoagulopathy. Logistic regression analyses revealed that Bb >1.57 μg/ml, syndecan-1 >66.6 ng/ml or D-dimer >6 mg/L at admission were associated with a higher risk of MOF/mortality. After adjusting for ISS, each increase of the triadic score defined above (Bb>1.57 µg/ml/Syndecan-1>66.6 ng/ml/D-dimer>6.0mg/L) was associated with a 6-fold higher in the odds ratio of MOF/death [OR: 6.83 (1.04-44.96, P=0.046], and a 4-fold greater in the odds of infectious complications [OR: 4.12 (1.04-16.36), P=0.044]. These findings provide preliminary evidence of two human injury response endotypes (traumatized triad and non-traumatized triad) that align with clinical trajectory, suggesting a potential endotype defined by a high triadic score. Patients with this endotype may be considered for timely intervention to create a pro-survival/organ-protective phenotype and improve clinical outcomes.

Biological signatures and prediction of an immunosuppressive status-persistent critical illness-among orthopedic trauma patients using machine learning techniques

BACKGROUND

Persistent critical illness (PerCI) is an immunosuppressive status. The underlying pathophysiology driving PerCI remains incompletely understood. The objectives of the study were to identify the biological signature of PerCI development, and to construct a reliable prediction model for patients who had suffered orthopedic trauma using machine learning techniques.

METHODS

This study enrolled 1257 patients from the Medical Information Mart for Intensive Care III (MIMIC-III) database. Lymphocytes were tracked from ICU admission to more than 20 days following admission to examine the dynamic changes over time. Over 40 possible variables were gathered for investigation. Patients were split 80:20 at random into a training cohort (n=1035) and an internal validation cohort (n=222). Four machine learning algorithms, including random forest, gradient boosting machine, decision tree, and support vector machine, and a logistic regression technique were utilized to train and optimize models using data from the training cohort. Patients in the internal validation cohort were used to validate models, and the optimal one was chosen. Patients from two large teaching hospitals were used for external validation (n=113). The key metrics that used to assess the prediction performance of models mainly included discrimination, calibration, and clinical usefulness. To encourage clinical application based on the optimal machine learning-based model, a web-based calculator was developed.

RESULTS

16.0% (201/1257) of all patients had PerCI in the MIMIC-III database. The means of lymphocytes (%) were consistently below the normal reference range across the time among PerCI patients (around 10.0%), whereas in patients without PerCI, the number of lymphocytes continued to increase and began to be in normal range on day 10 following ICU admission. Subgroup analysis demonstrated that patients with PerCI were in a more serious health condition at admission since those patients had worse nutritional status, more electrolyte imbalance and infection-related comorbidities, and more severe illness scores. Eight variables, including albumin, serum calcium, red cell volume distributing width (RDW), blood pH, heart rate, respiratory failure, pneumonia, and the Sepsis-related Organ Failure Assessment (SOFA) score, were significantly associated with PerCI, according to the least absolute shrinkage and selection operator (LASSO) logistic regression model combined with the 10-fold cross-validation. These variables were all included in the modelling. In comparison to other algorithms, the random forest had the optimal prediction ability with the highest area under receiver operating characteristic (AUROC) (0.823, 95% CI: 0.757-0.889), highest Youden index (1.571), and lowest Brier score (0.107). The AUROC in the external validation cohort was also up to 0.800 (95% CI: 0.688-0.912). Based on the risk stratification system, patients in the high-risk group had a 10.0-time greater chance of developing PerCI than those in the low-risk group. A web-based calculator was available at https://starxueshu-perci-prediction-main-9k8eof.streamlitapp.com/.

CONCLUSIONS

Patients with PerCI typically remain in an immunosuppressive status, but those without PerCI gradually regain normal immunity. The dynamic changes of lymphocytes can be a reliable biomarker for PerCI. This work developed a reliable model that may be helpful in improving early diagnosis and targeted intervention of PerCI. Beneficial interventions, such as improving nutritional status and immunity, maintaining electrolyte and acid-base balance, curbing infection, and promoting respiratory recovery, are early warranted to prevent the onset of PerCI, especially among patients in the high-risk group and those with a continuously low level of lymphocytes.

Cellular microRNAs correlate with clinical parameters in multiple injury patients

INTRODUCTION

The pathophysiology of the inflammatory response after major trauma is complex, and the magnitude correlates with severity of tissue injury and outcomes. Study of infection-mediated immune pathways has demonstrated that cellular microRNAs may modulate the inflammatory response. The authors hypothesize that the expression of microRNAs would correlate to complicated recoveries in polytrauma patients (PtPs).

METHODS

Polytrauma patients enrolled in the prospective observational Tissue and Data Acquisition Protocol with Injury Severity Score of >15 were selected for this study. Polytrauma patients were divided into complicated recoveries and uncomplicated recovery groups. Polytrauma patients' blood samples were obtained at the time of admission (T0). Established biomarkers of systemic inflammation, including cytokines and chemokines, were measured using multiplexed Luminex-based methods, and novel microRNAs were measured in plasma samples using multiplex RNA hybridization.

RESULTS

Polytrauma patients (n = 180) had high Injury Severity Score (26 [20-34]) and complicated recovery rate of 33%. MicroRNAs were lower in PtPs at T0 compared with healthy controls, and bivariate analysis demonstrated that variations of microRNAs correlated with age, race, comorbidities, venous thromboembolism, pulmonary complications, complicated recovery, and mortality. Positive correlations were noted between microRNAs and interleukin 10, vascular endothelial growth factor, Acute Physiology and Chronic Health Evaluation, and Sequential Organ Failure Assessment scores. Multivariable Lasso regression analysis of predictors of complicated recovery based on microRNAs, cytokines, and chemokines revealed that miR-21-3p and monocyte chemoattractant protein-1 were predictive of complicated recovery with an area under the curve of 0.78.

CONCLUSION

Systemic microRNAs were associated with poor outcomes in PtPs, and results are consistent with previously described trends in critically ill patients. These early biomarkers of inflammation might provide predictive utility in early complicated recovery diagnosis and prognosis. Because of their potential to regulate immune responses, microRNAs may provide therapeutic targets for immunomodulation.

LEVEL OF EVIDENCE

Diagnostic Tests/Criteria; Level II.

Clinical Criteria for Persistent Inflammation, Immunosuppression, and Catabolism Syndrome: An Exploratory Analysis of Optimal Cut-Off Values for Biomarkers

Background: While clinical criteria have been proposed for persistent inflammation, immunosuppression, and catabolism syndrome (PICS) using C-reactive protein (CRP), albumin, and lymphocyte count, there is no substantial basis for their optimal cut-off values. We herein aimed to develop and externally validate clinical criteria for PICS by investigating the optimal cut-off values for these biomarkers using machine-learning approaches and confirmed it with external validation. Methods: To develop criteria, we included ICU patients treated at a tertiary care hospital in Japan between 2018 and 2021 (derivation cohort). We introduced CRP, albumin and lymphocyte counts at around day 14 into six machine-learning models to predict PICS, defined as the compound outcome of the Barthel index (BI) < 70 at hospital discharge and in-hospital death. We incorporated the results of these models to assess the optimal cut-off values for biomarkers. We then developed and externally validated criteria for PICS using a nationwide claims database in Japan (validation cohort). Results: In the derivation cohort, 291 out of 441 patients had BI < 70 or in-hospital death. Based on machine-learning models, the optimal cut-off values for biomarkers to predict them were a CRP of 2.0 mg/dL, albumin of 3.0 g/dL, and a lymphocyte count of 800/μL, with an AUROC of 0.67. In the external validation cohort, 4492 out of 15,302 patients had BI < 70 or in-hospital death. The AUROC of the criteria was 0.71, with sensitivity of 0.71 and specificity of 0.68 to predict PICS. Conclusions: We herein provide a fundamental basis for PICS clinical criteria with CRP >2.0 mg/dL, albumin <3.0 g/dL, and a lymphocyte count <800/μL on day 14. The criteria developed will identify patients with PICS whose long-term mortality and activity of daily living may be poor.

Prevalence and Risk Factor Analysis of Post-Intensive Care Syndrome in Patients with COVID-19 Requiring Mechanical Ventilation: A Multicenter Prospective Observational Study

Introduction: Post-intensive care syndrome (PICS) is an emerging problem in critically ill patients and the prevalence and risk factors are unclear in patients with severe coronavirus disease 2019 (COVID-19). This multicenter prospective observational study aimed to investigate the prevalence and risk factors of PICS in ventilated patients with COVID-19 after ICU discharge. Methods: Questionnaires were administered twice in surviving patients with COVID-19 who had required mechanical ventilation, concerning Barthel Index, Short-Memory Questionnaire, and Hospital Anxiety and Depression Scale scores. The risk factors for PICS were examined using a multivariate logistic regression analysis. Results: The first and second PICS surveys were obtained at 5.5 and 13.5 months (mean) after ICU discharge, with 251 and 209 patients completing the questionnaires and with a prevalence of PICS of 58.6% and 60.8%, respectively, along with the highest percentages of cognitive impairment. Delirium (with an odds ratio of (OR) 2.34, 95% CI 1.1–4.9, and p = 0.03) and the duration of mechanical ventilation (with an OR of 1.29, 95% CI 1.05–1.58, and p = 0.02) were independently identified as the risk factors for PICS in the first PICS survey. Conclusion: Approximately 60% of the ventilated patients with COVID-19 experienced persistent PICS, especially delirium, and required longer mechanical ventilation.

The effect of age on the clinical characteristics and innate immune cell function in the patients with abdominal sepsis

Sepsis is a life-threatening dysregulated host response to infection that compromises organ health, and abdominal sepsis is a commonly presenting critical illness in intensive care units (ICU). In this study, we investigate the effect of age on clinical sepsis characteristics and innate immune cells (neutrophils and monocytes) functionality in abdominal sepsis patients. We recruited 32 patients with abdominal sepsis from the Beijing Ditan Hospital’s ICU from February 2021 to September 2021, and selected 18 healthy volunteers that were age- and sex-matched as controls for a prospective cohort study. Elderly abdominal sepsis patients (age >65 years) had the following altered characteristics compared to nonelderly patient controls: lower mean arterial pressure, monocytes percentage, and red blood cell volume distribution width (p < 0.05); higher neutrophils percentage and neutrophils-to-lymphocytes ratio (p < 0.05); significantly increased monocyte-produced reactive oxygen (p < 0.05); increases neutrophilic secretion of TNF-α, as well as lower monocytic secretion of TNF-α (p < 0.05); higher neutrophil percentage (which was significantly higher in peripheral blood than monocyte percentage). Elderly patients also had significantly increased phagocytic activity in their neutrophils and monocytes (p < 0.05), significantly reduced neutrophils-produced reactive oxygen (p < 0.001), and significantly increased TNF-α secretion by monocytes and neutrophils (p < 0.05). We found that elderly patients have decreased immune cell function and increased release of cytokines compared to younger patients, suggesting individualized treatment plans targeting the elderly septic microenvironment could help prevent organ failure in elderly septic patients and improves patient survival.

Analysis of Risk Factors for Postoperative Lower Extremity Deep Venous Thrombosis and its Treatment and Nursing

Objective

To explore the risk factors of lower extremity deep venous thrombosis (LEDVT) after surgery and discuss the treatment and nursing countermeasures.

Methods

A retrospective analysis was conducted on 268 surgical patients admitted between July to December 2021. The factors associated with LEDVT were analyzed using the Logistic regression model. Further, LEDVT patients were assigned to a research group treated with targeted nursing to prevent LEDVT and a control group that used routine care. Coagulation function and inflammatory cytokines before and after nursing intervention were compared between groups. The assessment of patients' mobility employed the lower limb motor function part of the Fugel–Meyer Assessment (FMA), Harris Hip Score (HHS), and Barthel index (BI), and their psychological status was evaluated using the Kolcaba's General Comfort Questionnaire (GCQ) and Self-rating Anxiety/Depression Scale (SAS/SDS). Finally, patient satisfaction with the treatment service was investigated.

Results

Logistic regression analysis showed that hypertension, limb paralysis, central venous catheterization of lower limbs, and bedridden time affect postoperative LEDVT in an independent way (P < 0.05). After the intervention, the coagulation function and inflammatory reaction were improved in both groups, with more significant improvement in the research group (P < 0.05). The research group also showed higher FMA, Harris, GCQ, and BI scores while lower SAS and SDS scores than the control group postnursing intervention (P < 0.05). Finally, a higher satisfaction rate was identified in the research group as compared to the control group (P < 0.05).

Conclusion

Hypertension, limb paralysis, CVC of lower limbs, and bedridden time are all independent risk factors for LEDVT after surgery. The implementation of targeted nursing strategies for the above factors can effectively alleviate the hypercoagulable state of patients after operation, reduce inflammatory responses, and improve patient comfort, which is of great significance for preventing the occurrence of LEDVT.

Inflammation in kidney repair: Mechanism and therapeutic potential

The kidney has a remarkable ability of repair after acute kidney injury (AKI). However, when injury is severe or persistent, the repair is incomplete or maladaptive and may lead to chronic kidney disease (CKD). Maladaptive kidney repair involves multiple cell types and multifactorial processes, of which inflammation is a key component. In the process of inflammation, there is a bidirectional interplay between kidney parenchymal cells and the immune system. The extensive and complex crosstalk between renal tubular epithelial cells and interstitial cells, including immune cells, fibroblasts, and endothelial cells, governs the repair and recovery of the injured kidney. Further research in this field is imperative for the discovery of biomarkers and promising therapeutic targets for kidney repair. In this review, we summarize the latest progress in the immune response and inflammation during maladaptive kidney repair, analyzing the interaction between immune cells and intrinsic kidney cells, pointing out the potentialities of inflammation-related pathways as therapeutic targets, and discussing the challenges and future research prospects in this field.

Immune dysfunction following severe trauma: A systems failure from the central nervous system to mitochondria

When a traumatic injury exceeds the body's internal tolerances, the innate immune and inflammatory systems are rapidly activated, and if not contained early, increase morbidity and mortality. Early deaths after hospital admission are mostly from central nervous system (CNS) trauma, hemorrhage and circulatory collapse (30%), and later deaths from hyperinflammation, immunosuppression, infection, sepsis, acute respiratory distress, and multiple organ failure (20%). The molecular drivers of secondary injury include damage associated molecular patterns (DAMPs), pathogen associated molecular patterns (PAMPs) and other immune-modifying agents that activate the hypothalamic-pituitary-adrenal (HPA) axis and sympathetic stress response. Despite a number of drugs targeting specific anti-inflammatory and immune pathways showing promise in animal models, the majority have failed to translate. Reasons for failure include difficulty to replicate the heterogeneity of humans, poorly designed trials, inappropriate use of specific pathogen-free (SPF) animals, ignoring sex-specific differences, and the flawed practice of single-nodal targeting. Systems interconnectedness is a major overlooked factor. We argue that if the CNS is protected early after major trauma and control of cardiovascular function is maintained, the endothelial-glycocalyx will be protected, sufficient oxygen will be delivered, mitochondrial energetics will be maintained, inflammation will be resolved and immune dysfunction will be minimized. The current challenge is to develop new systems-based drugs that target the CNS coupling of whole-body function.

Simultaneous C5 and CD14 inhibition limits inflammation and organ dysfunction in pig polytrauma

Dysfunctional complement activation and Toll-like receptor signaling immediately after trauma are associated with development of trauma-induced coagulopathy and multiple organ dysfunction syndrome. We assessed the efficacy of the combined inhibition therapy of complement factor C5 and the TLR co-receptor CD14 on thrombo-inflammation and organ damage in an exploratory 72-h polytrauma porcine model, conducted under standard surgical and intensive care management procedures. Twelve male pigs were subjected to polytrauma, followed by resuscitation (ATLS® guidelines) and operation of the femur fracture (intramedullary nailing technique). The pigs were allocated to combined C5 and CD14 inhibition therapy group (n=4) and control group (n=8). The therapy group received intravenously C5 inhibitor (RA101295) and anti-CD14 antibody (rMil2) 30 min post-trauma. Controls received saline. Combined C5 and CD14 inhibition reduced the blood levels of the terminal complement complex (TCC) by 70% (p=0.004), CRP by 28% (p=0.004), and IL-6 by 52% (p=0.048). The inhibition therapy prevented the platelet consumption by 18% and TAT formation by 77% (p=0.008). Moreover, the norepinephrine requirements in the treated group were reduced by 88%. The inhibition therapy limited the organ damage, thereby reducing the blood lipase values by 50% (p=0.028), LDH by 30% (p=0.004), AST by 33%, and NGAL by 30%. Immunofluorescent analysis of the lung tissue revealed C5b-9 deposition on blood vessels in five from the untreated, and in none of the treated animals. In kidney and liver, the C5b-9 deposition was similarly detected mainly the untreated as compared to the treated animals. Combined C5 and CD14 inhibition limited the inflammatory response, the organ damage, and reduced the catecholamine requirements after experimental polytrauma and might be a promising therapeutic approach.

Time to Look for Another Infectious Source? White Blood Cell Trends during Ventilator-Associated Pneumonia

Background: Ventilator-associated pneumonia (VAP) continues to plague patients in intensive care units (ICUs) throughout the world. Persistent leukocytosis despite antibiotic treatment for VAP can have many etiologies including normal inflammatory response, inadequate VAP antimicrobial therapy, and the presence of additional infectious diagnoses. Hypothesis: Surgical patients with VAP and a second infectious source have a different white blood cell count (WBC) trend than patients with VAP alone. Patients and Methods: Retrospective, single-center study of surgical ICU patients diagnosed with VAP (>10⁴ CFU/mL on semi-quantitative culture) between January 2019 and June 2020. Chart review identified additional infections diagnosed during VAP treatment. White blood cell count values were compared between patients treated for VAP alone (VAP-alone) and those with additional infections (VAP-plus) using a Wilcoxon test. Univariable analysis compared admission type, surgeries, and steroid use between cohorts. Results: Eighty-eight VAPs were included for analysis; 61 (69%) were VAP-alone and 27 (31%) VAP-plus. Average age was 47.1 ± 16.7 years, 78% were male, and 93% were trauma admissions. Median hospital day of VAP diagnosis was six (interquartile range [IQR], 4-10). Nearly all patients (99%) were started on initial antibiotic agents to which the VAP organism was sensitive. Daily WBC was higher for VAP-plus compared with VAP-alone on days five, six, and seven of treatment. The maximum WBC was higher for VAP-plus (21.6 k/mcL vs. 16.1 k/mcL; p = 0.02). There were no differences in admission types, number of surgeries, or steroid use between groups. Conclusions: Providers should have increased suspicion for additional sources of infection when ICU patients with a VAP continue to have elevated WBC despite appropriate antibiotic therapy.

Lymphocyte trajectories are associated with prognosis in critically ill patients: A convenient way to monitor immune status

Background

Immunosuppression is a risk factor for poor prognosis of critically ill patients, but current monitoring of the immune status in clinical practice is still inadequate. Absolute lymphocyte count (ALC) is not only a convenient biomarker for immune status monitoring but is also suitable for clinical application. In this study, we aimed to explore different trajectories of ALC, and evaluate their relationship with prognosis in critically ill patients.

Methods

We retrospectively enrolled 10,619 critically ill patients admitted to a general intensive care unit (ICU) with 56 beds from February 2016 to May 2020. Dynamic ALC was defined as continuous ALC from before ICU admission to 5 days after ICU admission. Initial ALC was defined as the minimum ALC within 48 h after ICU admission. Group-based trajectory modeling (GBTM) was used to group critically ill patients according to dynamic ALC. Multivariate cox regression model was used to determine the independent association of trajectory endotypes with death and persistent inflammation, immunosuppression, catabolism syndrome (PICS).

Results

A total of 2022 critically ill patients were unsupervisedly divided into four endotypes based on dynamic ALC, including persistent lymphopenia endotype (n = 1,211; 58.5%), slowly rising endotype (n = 443; 22.6%), rapidly decreasing endotype (n = 281; 14.5%) and normal fluctuation endotype (n = 87; 4.4%). Among the four trajectory endotypes, the persistent lymphopenia endotype had the highest incidence of PICS (24.9%), hospital mortality (14.5%) and 28-day mortality (10.8%). In multivariate cox regression model, persistent lymphopenia was associated with increased risk of 28-day mortality (HR: 1.54; 95% CI: 1.06–2.23), hospital mortality (HR: 1.66; 95% CI: 1.20–2.29) and PICS (HR: 1.79; 95% CI: 1.09–2.94), respectively. Sensitivity analysis further confirmed that the ALC trajectory model of non-infected patients and non-elderly patients can accurately distinguished 91 and 90% of critically ill patients into the same endotypes as the original model, respectively.

Conclusion

The ALC trajectory model is helpful for grouping critically ill patients, and early persistent lymphopenia is associated with poor prognosis. Notably, persistent lymphopenia may be a robust signal of immunosuppression in critically ill patients.

Sex differences associate with late microbiome alterations after murine surgical sepsis

BACKGROUND

Sepsis-induced gut microbiome alterations contribute to sepsis-related morbidity and mortality. Given evidence for improved postsepsis outcomes in females compared with males, we hypothesized that female mice maintain microbiota resilience versus males.

METHODS

Mixed-sex C57BL/6 mice underwent cecal ligation and puncture (CLP) with antibiotics, saline resuscitation, and daily chronic stress and were compared with naive (nonsepsis/no antibiotics) controls. For this work, the results of young (3-5 months) and old (18-22 months) adult mice were analyzed by sex, independent and dependent of age. Mice were sacrificed at days 7 and 14, and 16S rRNA gene sequencing was performed on fecal bacterial DNA. α and β diversity were determined by Shannon index and Bray-Curtis with principal coordinate analysis, respectively. False discovery rate (FDR) correction was implemented to account for potential housing effect.

RESULTS

In control mice, there was no difference in α or β diversity between male and female mice (FDR, 0.76 and 0.99, respectively). However, male mice that underwent CLP with daily chronic stress had a decrease in microbiota α diversity at 7 days post-CLP (Shannon FDR, 0.005), which was sustained at 14 days post-CLP (Shannon FDR, 0.001), compared with baseline. In addition, male mice maintained differences in β diversity even at day 14 compared with controls (FDR, <0.0001). In contrast, female mice had a decreased microbiota α diversity (Shannon FDR, 0.03) and β diversity (FDR, 0.02) 7 days post-CLP but recovered their α and β diversity by post-CLP day 14 (Shannon FDR, 0.5, and FDR, 0.02, respectively). Further analysis of females revealed that only young female mice were not different (β diversity) post-CLP day 14 to controls.

CONCLUSION

Although sepsis-induced perturbations of the intestinal microbiota occur initially in both male and female C57BL/6 mice, females demonstrate different microbiota by day 14. This may be seen primarily in younger females. This difference in recovery may play a role in outcome differences between sexes after sepsis.

Hypercatabolism and Anti-catabolic Therapies in the Persistent Inflammation, Immunosuppression, and Catabolism Syndrome

Owing to the development of intensive care units, many patients survive their initial insults but progress to chronic critical illness (CCI). Patients with CCI are characterized by prolonged hospitalization, poor outcomes, and significant long-term mortality. Some of these patients get into a state of persistent low-grade inflammation, suppressed immunity, and ongoing catabolism, which was defined as persistent inflammation, immunosuppression, and catabolism syndrome (PICS) in 2012. Over the past few years, some progress has been made in the treatment of PICS. However, most of the existing studies are about the role of persistent inflammation and suppressed immunity in PICS. As one of the hallmarks of PICS, hypercatabolism has received little research attention. In this review, we explore the potential pathophysiological changes and molecular mechanisms of hypercatabolism and its role in PICS. In addition, we summarize current therapies for improving the hypercatabolic status and recommendations for patients with PICS.

The Clinical Impact of Platelets on Post-Injury Serum Creatinine Concentration in Multiple Trauma Patients: A Retrospective Cohort Study

Background and objective: Platelets contribute to the immunological response after multiple trauma. To determine the clinical impact, this study analyzes the association between platelets and creatinine concentration as an indicator of kidney function in polytraumatized patients. Methods: We investigated all patients presenting an Injury Severity Score (ISS) ≥16 for a 2-year period at our trauma center. Platelet counts and creatinine concentrations were analyzed, and correlation analysis was performed within 10 days after multiple trauma. Results: 83 patients with a median ISS of 22 were included. Platelet count was decreased on day 3 (p ≤ 0.001) and increased on day 10 (p ≤ 0.001). Platelet count was elevated on day 10 in younger patients and diminished in severely injured patients (ISS ≥35) on day 1 (p = 0.012) and day 3 (p = 0.011). Creatinine concentration was decreased on day 1 (p = 0.003) and day 10 (p ≤ 0.001) in female patients. Age (p = 0.01), male sex (p = 0.004), and injury severity (p = 0.014) were identified as factors for increased creatinine concentration on day 1, whereas platelets (p = 0.046) were associated with decreased creatinine concentrations on day 5 after multiple trauma. Conclusions: Kinetics of platelet count and creatinine concentration are influenced by age, gender, and trauma severity. There was no clear correlation between platelet counts and creatinine concentration. However, platelets seem to have a modulating effect on creatinine concentrations in the vulnerable phase after trauma.

Cerebral dysfunctions caused by sepsis during ageing

Systemic inflammation elicited by sepsis can induce an acute cerebral dysfunction known as sepsis-associated encephalopathy (SAE). Recent evidence suggests that SAE is common but shows a dynamic trajectory over time. Half of all patients with sepsis develop SAE in the intensive care unit, and some survivors present with sustained cognitive impairments for several years after initial sepsis onset. It is not clear why some, but not all, patients develop SAE and also the factors that determine the persistence of SAE. Here, we first summarize the chronic pathology and the dynamic changes in cognitive functions seen after the onset of sepsis. We then outline the cerebral effects of sepsis, such as neuroinflammation, alterations in neuronal synapses and neurovascular changes. We discuss the key factors that might contribute to the development and persistence of SAE in older patients, including premorbid neurodegenerative pathology, side effects of sedatives, renal dysfunction and latent virus reactivation. Finally, we postulate that some of the mechanisms that underpin neuropathology in SAE may also be relevant to delirium and persisting cognitive impairments that are seen in patients with severe COVID-19.

Inflammatory cytokines associated with outcomes in orthopedic trauma patients independent of New Injury Severity score: A pilot prospective cohort study

Traumatic injury is the leading cause of mortality in patients under 50. It is associated with a complex inflammatory response involving hormonal, immunologic, and metabolic mediators. The marked elevation of cytokines and inflammatory mediators subsequently correlates with the development of posttraumatic complications. The aim was to determine whether elevated cytokine levels provide a predictive value for orthopedic trauma patients. A prospective cohort study of patients with New Injury Severity Score (NISS) > 5 was undertaken. IL-6, IL-8, IL-10, and migration inhibitory factor levels were measured within 24-h of presentation. Demographic covariates and clinical outcomes were obtained from the medical records. Fifty-eight patients (83% male, 40 years) were included. Addition of IL-6 to baseline models significantly improved prediction of pulmonary complication (LR = 6.21, p = 0.01), ICU (change in R²  = 0.31, p < 0.01), and hospital length of stay (change in R²  = 0.16, p < 0.01). The addition of IL-8 significantly improved the prediction of acute kidney injury (LR = 9.15, p < 0.01). The addition of postinjury IL-6 level to baseline New Injury Severity Score model is better able to predict the occurrence of pulmonary complications as well as prolonged ICU and hospital length of stay.