Sepsis and Immunosenescence in the Elderly Patient: A Review

Amyloid A and lactic acid as a predictor in patients with sepsis in patients with liver cirrhosis

BACKGROUND

Sepsis is triggered by pathogenic microorganisms, resulting in a systemic inflammatory response. Liver cirrhosis and sepsis create a vicious cycle: cirrhosis weakens immune function, raising infection risk and hindering pathogen clearance. Optimal treatment outcomes depend on understanding liver cirrhosis patients' sepsis risk factors. Thus, preventing sepsis involves addressing these risk factors. Therefore, early identification and understanding of clinical characteristics in liver cirrhosis patients with sepsis are crucial for selecting appropriate antibiotics. A case-control study using logistic regression was conducted to examine the prognostic value of amyloid A/lactate level monitoring in identifying sepsis risk factors in liver cirrhosis patients.

METHODS

From March 2020 to March 2022, 136 liver cirrhosis patients treated at our hospital were divided into a sepsis group (n = 35) and a non-sepsis group (n = 101) based on sepsis complications. General clinical data were collected. Univariate analysis screened for liver cirrhosis patients' sepsis risk factors. Multivariate logistic analysis was subsequently employed to evaluate the risk factors. Sepsis patients were followed up for a month. Based on prognosis, patients were categorized into a poor prognosis group (n = 16) and a good prognosis group (n = 19). Serum amyloid A (SAA) and blood lactic acid (BLA) levels were compared between the two groups. The receiver operating characteristic (ROC) curve was used to evaluate the prognostic value of both individual and combined SAA/BLA monitoring.

RESULTS

Patient data, including age, diabetes history, liver cancer, hepatic artery embolization, recent antibiotic use, invasive procedures within two weeks, APACHE II Scoring, ALB and SAA and BLA levels, were compared between the sepsis and non-sepsis groups, showing significant differences (P < 0.05). Logistic regression identified factors such as age ≥ 70, recent antibiotic use, recent invasive procedures, history of liver cancer, hepatic artery embolization history, high APACHE II scores, decreased albumin, and elevated SAA and BLA levels as independent sepsis risk factors in liver cirrhosis patients (P < 0.05). Among the 35 sepsis patients, 16 had a poor prognosis, representing an incidence rate of 45.71%. Serum SAA and BLA levels were significantly higher in the poor prognosis group than in the good prognosis group (P < 0.05). The AUC for serum SAA and BLA was 0.831 (95%CI: 0.738-0.924), 0.720 (95%CI: 0.600-0.840), and 0.909 (95%CI: 0.847-0.972), respectively. The combined diagnostic AUC was significantly higher than that of single factor predictions (P < 0.05). The predictive value ranked as follows: joint detection > SAA > BLA.

CONCLUSION

In treating liver cirrhosis, prioritize patients with advanced age, a history of hepatic artery embolization, recent invasive operations, history of liver cancer, recent antibiotic exposure, high APACHE II scores and low albumin. Closely monitoring serum SAA and BLA levels in these patients can offer valuable insights for early clinical prevention and treatment.

Influence of lymphopenia on long-term mortality in septic shock, a retrospective observational study

BACKGROUND AND OBJECTIVE

The diagnosis of infection, to diagnose septic shock, has been qualified by leukocyte counts and protein biomarkers. Septic shock mortality is persistently high (20%-50%), and rising in the long term. The definition of sepsis does not include leukocyte count, and lymphopenia has been associated with its mortality in the short term. Immunosuppression and increased mortality in the long term due to sepsis have not been demonstrated. The aim is to relate the occurrence of lymphopenia and its lack of recovery during septic shock with mortality at 2 years.

PATIENTS AND METHODS

Cohort of 332 elderly patients diagnosed with septic shock. Mortality at 28 days and 2 years was analysed according to leukocyte, neutrophil, and lymphocyte counts, and the ability to recover from lymphopenia (LRec).

RESULTS

A total of 74.1% of patients showed lymphopenia, and 73.5% did not improve during ICU stay. Mortality was 31.0% and 50.3% at 28 days and 2 years, respectively. Lymphopenia was a predictor of early mortality (OR 2.96) and LRec of late mortality (OR 3.98). Long-term mortality was associated with LRec (HR 1.69).

CONCLUSIONS

In elderly patients with septic shock, 28-day mortality is associated with lymphopenia and neutrophilia, and LRec with 2-year mortality; this may represent 2 distinct phenotypes of behaviour after septic shock.

Vagus nerve stimulation modulates distinct acetylcholine receptors on B cells and limits the germinal center response

Acetylcholine is produced in the spleen in response to vagus nerve activation; however, the effects on antibody production have been largely unexplored. Here, we use a chronic vagus nerve stimulation (VNS) mouse model to study the effect of VNS on T-dependent B cell responses. We observed lower titers of high-affinity IgG and fewer antigen-specific germinal center (GC) B cells. GC B cells from chronic VNS mice exhibited altered mRNA and protein expression suggesting increased apoptosis and impaired plasma cell differentiation. Follicular dendritic cell (FDC) cluster dispersal and altered gene expression suggested poor function. The absence of acetylcholine-producing CD4+ T cells diminished these alterations. In vitro studies revealed that α7 and α9 nicotinic acetylcholine receptors (nAChRs) directly regulated B cell production of TNF, a cytokine crucial to FDC clustering. α4 nAChR inhibited coligation of CD19 to the B cell receptor, presumably decreasing B cell survival. Thus, VNS-induced GC impairment can be attributed to distinct effects of nAChRs on B cells.

The obesity paradox in younger adult patients with sepsis: analysis of the MIMIC-IV database

BACKGROUND

The obesity paradox suggests that individuals with obesity may have a survival advantage against specific critical illnesses, including sepsis. However, whether this paradox occurs at younger ages remains unclear. Therefore, we aimed to investigate whether obesity could improve survival in younger adult patients with sepsis.

METHODS

We used clinical data sourced from the Medical Information Mart for Intensive Care IV (MIMIC-IV) database. Patients with Sequential Organ Failure Assessment score ≥2 and suspected infection at the time of ICU admission were identified as having sepsis, following the Sepsis-3 definition. Individuals were classified into the obesity (BMI ≥30 kg/m²) and non-obesity (BMI <30 kg/m²) groups. Patients aged <50 and ≥50 years were categorized as younger adult patients and older patients, respectively.

RESULTS

Of 73,181 patients in the MIMIC-IV ICU database, 18,120 satisfied the inclusion criteria: 2642 aged <50 years and 15,478 aged ≥50 years. The Kaplan-Meier curve showed that obesity was not associated with an improved mortality rate among younger adult patients with sepsis (log-rank test: P = 0.197), while obesity exhibited a survival benefit in older patients with sepsis (log-rank test: P < 0.001). After propensity score matching, in-hospital mortality did not differ significantly between the obesity and non-obesity groups (13.3% vs. 12.2%; P = 0.457) in the younger adult patients with sepsis. Multivariate logistic regression analysis revealed that BMI was not an independent risk factor for in-hospital mortality in younger adult patients with sepsis (underweight: adjusted odds ratio [aOR] 1.72, P = 0.076; overweight: aOR 0.88, P = 0.437; obesity: aOR 0.93, P = 0.677; and severe obesity: aOR 1.22, P = 0.580, with normal weight as the reference).

CONCLUSION

Contrary to findings regarding older patients with sepsis, our findings suggest that the obesity paradox does not apply to younger adult patients with sepsis.

Age-associated accumulation of B cells promotes macrophage inflammation and inhibits lipolysis in adipose tissue during sepsis

Non-canonical lipolysis induced by inflammatory cytokines or Toll-like receptor ligands is required for the regulation of inflammation during endotoxemia and sepsis. Canonical lipolysis induced by catecholamines declines during aging due to factors including an expansion of lymphocytes, pro-inflammatory macrophage polarization, and an increase in chronic low-grade inflammation; however, the extent to which the non-canonical pathway of lipolysis is active and impacted by immune cells during aging remains unclear. Therefore, we aimed to define the extent to which immune cells from old mice influence non-canonical lipolysis during sepsis. We identified age-associated impairments of non-canonical lipolysis and an accumulation of dysfunctional B1 B cells in the visceral white adipose tissue (vWAT) of old mice. Lifelong deficiency of B cells results in restored non-canonical lipolysis and reductions in pro-inflammatory macrophage populations. Our study suggests that targeting the B cell-macrophage signaling axis may resolve metabolic dysfunction in aged vWAT and attenuate septic severity in older individuals.

Changes in Early T-Cell Subsets and Their Impact on Prognosis in Patients with Sepsis: A Single-Center Retrospective Study

Objective

To analyze the early changes in CD3+, CD4+, and CD8+T-cell subset counts in patients with sepsis and their correlation with prognosis to provide a feasible basis for clinical immunomodulation in sepsis.

Methods

This is a single-center retrospective study. The study enrolled sepsis patients (meeting SEPSIS 3.0 definition) who were admitted to the Department of Intensive Care Unit at the First Hospital of Jilin University from July 5th, 2018 to December 5th, 2019 and were aged 18 years or above. In addition, these patients underwent cellular immune testing (CD3+, CD4+, CD8+ T lymphocyte counts, and CD4+/CD8+ ratio) within 24 hours of ICU admission. Patient's clinical data including age, gender, infection site, APACHE II score, SOFA score, length of ICU stay, mechanical ventilation time, ICU mortality, 28-day mortality, and 3-year survival status were collected. The prognostic indicators and survival of the decreased and nondecreased groups of different subsets of T lymphocyte counts and CD4+/CD8+ ratio were compared.

Results

A total of 206 patients were enrolled, with 76.7% having a decrease in CD3+ T lymphocyte count, 76.7% having a decrease in CD4+ T lymphocyte count, and 63.6% having a decrease in CD8+ T lymphocyte count. Furthermore, 21.8% had a lower CD4+/CD8+ ratio. Analysis showed that the CD3+ T lymphocyte count decreased group had a longer length of ICU stay [11 d (4, 21) vs. 7 d (4, 17), P=0.03], increased percentage of mechanical ventilation (67.5% vs. 51.0%, P=0.04), and extended mechanical ventilation time [144 h (48, 360) vs. 96 h (48, 144), P=0.04] compared to the nondecreased group. The 28-day mortality was higher in the decreased group of CD4+/CD8+ ratio compared to the nondecreased group (33.3% vs. 25.5%, P=0.29); however, the difference did not reach statistical significance. Logistic regression analysis revealed no significant correlation between the decrease in CD4+/CD8+ ratio and 28-day mortality (P=0.11). The 3-year follow-up revealed that the CD4+/CD8+ decreased group had a lower survival rate than the nondecreased group (33.3% vs. 53.4%, P=0.01).

Conclusions

In the early stage of sepsis, most patients showed a decrease in CD3+, CD4+, and CD8+T-cell subsets, as well as in the CD4+/CD8+ ratio. The decrease in CD3+ and CD4+/CD8+ was related to some poor prognosis.

Anisodamine hydrobromide in the treatment of critically ill patients with septic shock: a multicenter randomized controlled trial

BACKGROUND

Septic shock is the development of sepsis to refractory circulatory collapse and metabolic derangements, characterized by persistent hypotension and increased lactate levels. Anisodamine hydrobromide (Ani HBr) is a Chinese medicine used to improve blood flow in circulatory disorders. The purpose of this study was to determine the therapeutic efficacy of Ani HBr in the treatment of patients with septic shock.

METHODS

This was a prospective, multicenter, randomized controlled trial focusing on patients with septic shock in 16 hospitals in China. Patients were randomly assigned in a 1:1 ratio to either the treatment group or the control group. The primary endpoint was 28-day mortality. The secondary outcomes included 7-day mortality, hospital mortality, hospital length of stay, vasopressor-free days within 7 days, etc. These indicators were measured and collected at 0, 6h, 24h, 48h, 72h and 7d after the diagnosis.

RESULTS

Between September 2017 and March 2021, 404 subjects were enrolled. 203 subjects received Ani HBr and 201 subjects were assigned to the control group. The treated group showed lower 28-day mortality than the control group. Stratified analysis further showed significant differences in 28-day mortality between the two groups for patients with a high level of illness severity. We also observed significant differences in 7-day mortality, hospital mortality and some other clinical indicators between the two groups.

CONCLUSION

Ani HBr might be an important adjuvant to conventional treatment to reduce 28-day mortality in patients with septic shock. A large-scale prospective randomized multicenter trial is warranted to confirm our results.

Host test based on tumor necrosis factor-related apoptosis-inducing ligand, interferon gamma-induced protein-10 and C-reactive protein for differentiating bacterial and viral respiratory tract infections in adults: diagnostic accuracy study

OBJECTIVES

To assess the performance of a test (called BV), integrating the blood levels of three immune proteins into a score, to differentiate bacterial from viral infection among adults with suspected lower respiratory tract infection (LRTI).

METHODS

Prospective diagnostic accuracy study, enrolling febrile adults >18 years with LRTI signs or symptoms for less than 7 days presenting to several hospitals' emergency departments in Israel. The main exclusion criterion was immunodeficiency. Reference standard diagnosis (bacterial/viral/indeterminate) was based on three experts independently reviewing comprehensive patient data including follow-up data. BV generated three results: viral infection or other nonbacterial condition (0 ≤ score < 35), equivocal (35 ≤ score ≤ 65) and bacterial infection including co-infection (65 < score ≤ 100). BV performance was assessed against the reference standard with indeterminate reference standard and equivocal BV cases removed.

RESULTS

Of 490 enrolled patients, 415 met eligibility criteria (median age 56 years, interquartile range 35). The reference standard classified 104 patients as bacterial, 210 as viral and 101 as indeterminate. BV was equivocal in 9.6% (30/314). Excluding indeterminate reference standard diagnoses and equivocal BV results, BV's sensitivity for bacterial infection was 98.1% (101/103; 95% confidence interval 95.4-100), specificity 88.4% (160/181; 83.7-93.1) and negative predictive value 98.8% (160/162; 97.1-100).

DISCUSSION

BV exhibited high diagnostic performance for febrile adults with suspected LRTI among patients with reference standard diagnoses of bacterial or viral LRTI.

Staphylococcus aureus phagocytosis is affected by senescence

Senescent cells accumulate in multicellular animals with aging, resulting in organ or tissue dysfunction. These alterations increase the incidence of a variety of illnesses, including infectious diseases, and, in certain instances, its severity. In search of a rationale for this phenomenon, we focused on the endophagocytic pathway in senescent cells. We first described the endocytic vesicle populations at different stages of maturation using confocal microscopy. There was an increase in the number of vacuoles per cell, which was partially explained by an increase in cell size. No changes in vesicle maturation or degradation capacities were determined by microscopy or Western blot assays. Also, we studied the internalization of various endophagocytic cargoes in senescent cells and observed only a decrease in the intracellular recovery of bacteria such as Staphylococcus aureus. Afterwards, we studied the intracellular traffic of S. aureus, and observed no differences in the infection between control and senescent cells. In addition we quantified the recovery of bacteria from control and senescent cells infected in the presence of several inhibitors of endophagosomal maturation, and no changes were observed. These results suggest that bacterial internalization is affected in senescent cells. Indeed, we confirmed this hypothesis by determining minor bacterial adherence and internalization by confocal microscopy. Furthermore, it is important to highlight that we found very similar results with cells from aged animals, specifically BMDMs. This alteration in senescent cells enlightens the diminished bacterial clearance and may be a factor that increases the propensity to suffer severe infectious conditions in the elderly.

Costs and Consequences of a Novel Emergency Department Sepsis Diagnostic Test: The IntelliSep Index

Sepsis causes 270,000 deaths and costs $38 billion annually in the United States. Most cases of sepsis present in the emergency department (ED), where rapid diagnosis remains challenging. The IntelliSep Index (ISI) is a novel diagnostic test that analyzes characteristics of WBC structure and provides a reliable early signal for sepsis. This study performs a cost-consequence analysis of the ISI relative to procalcitonin for early sepsis diagnosis in the ED.

PERSPECTIVE

U.S. healthcare system.

SETTING

Community hospital ED.

METHODS

A decision tree analysis was performed comparing ISI with procalcitonin. Model parameters included prevalence of sepsis, sensitivity and specificity of diagnostic tests (both ISI and procalcitonin), costs of hospitalization, and mortality rate stratified by diagnostic test result. Mortality and prevalence of sepsis were estimated from best available literature. Costs were estimated based on an analysis of a large, national discharge dataset, and adjusted to 2018 U.S. dollars. Outcomes included expected costs and survival.

RESULTS

Assuming a confirmed sepsis prevalence of 16.9% (adjudicated to Sepsis-3), the ISI strategy had an expected cost per patient of $3,849 and expected survival rate of 95.08%, whereas the procalcitonin strategy had an expected cost of $4,656 per patient and an expected survival of 94.98%. ISI was both less costly and more effective than procalcitonin, primarily because of fewer false-negative results. These results were robust in sensitivity analyses.

CONCLUSIONS

ISI was both less costly and more effective in preventing mortality than procalcitonin, primarily because of fewer false-negative results. The ISI may provide health systems with a higher-value diagnostic test in ED sepsis evaluation. Additional work is needed to validate these results in clinical practice.

Up-regulation of Myocardial Klotho Expression to Promote Cardiac Functional Recovery in Old Mice following Endotoxemia

Objective

Endotoxemic cardiac dysfunction contributes to greater morbidity and mortality in elderly patients with sepsis. This study tested the hypothesis that Klotho insufficiency in aging heart exaggerates and prolongs myocardial inflammation to hinder cardiac function recovery following endotoxemia.

Methods

Endotoxin (0.5 mg/kg, iv) was administered to young adult (3-4 months) and old (18-22 months) mice with or without subsequent treatment with recombinant interleukin-37 (IL-37, 50 μg/kg, iv) or recombinant Klotho (10 μg/kg, iv). Cardiac function was analyzed using a microcatheter 24, 48 and 96 h later. Myocardial levels of Klotho, ICAM-1, VCAM-1 and IL-6 were determined by immunoblotting and ELISA.

Results

In comparison to young adult mice, old mice had worse cardiac dysfunction accompanied by greater myocardial levels of ICAM-1, VCAM-1 and IL-6 at each time point following endotoxemia and failed to fully recover cardiac function by 96 h. The exacerbated myocardial inflammation and cardiac dysfunction were associated with endotoxemia-caused further reduction of lower myocardial Klotho level in old mice. Recombinant IL-37 promoted inflammation resolution and cardiac functional recovery in old mice. Interestingly, recombinant IL-37 markedly up-regulated myocardial Klotho levels in old mice with or without endotoxemia. Similarly, recombinant Klotho suppressed myocardial inflammatory response and promoted inflammation resolution in old endotoxemic mice, leading to complete recovery of cardiac function by 96 h.

Conclusion

Myocardial Klotho insufficiency in old endotoxemic mice exacerbates myocardial inflammatory response, impairs inflammation resolution and thereby hinders cardiac functional recovery. IL-37 is capable of up-regulating myocardial Klotho expression to improve cardiac functional recovery in old endotoxemic mice.

Curcumin interferes with sepsis-induced cardiomyocyte apoptosis via TLR1 inhibition

OBJECTIVE

Sepsis-induced cardiomyopathy is the leading cause of death in sepsis and is characterized by reversible myocardial depression. However, the specific mechanisms responsible for myocardial injury in sepsis are not known. The present study used bioinformatic analysis to explore the possible mechanisms of sepsis-induced myocardial injury and the therapeutic potential of curcumin.

METHODS

The GSE125042 microarray gene expression matrix was obtained from the Gene Expression Omnibus database, which includes 10 septic cardiomyocyte samples from cecum ligation perforation constructs and 10 sham-operated groups cardiomyocyte samples. Background correction and matrix data normalization were performed using the robust multiarray average algorithm. Differentially expressed genes (DEGs) screening was performed using the Limma R package expression matrix, and whole gene analysis was performed using the weighted gene co-expression network analysis R package to construct gene networks and identify modules. Enrichment analysis and gene set enrichment analysis was performed on the genes to be selected. Construct cellular and animal models of myocardial injury in sepsis were assessed and the effects of curcumin on a rat or cardiac myocytes were observed.

RESULTS

A total of 2876 DEGs were screened based on the GSE125042 chip, of which 1424 genes were upregulated and 1452 genes were down regulated. WGCNA analysis of the whole genes was also performed and a total of 20 gene modules were generated. Among them, the selected TLR1 gene was present in the most strongly correlated Brown module. Enrichment analysis of the upregulated DEGs with the Brown module showed that they were significantly enriched in biological processes related to ribosomal protein complex generation, cellular components related to phagocytic vesicles and molecular functions related to Toll-like receptor binding, affecting cardiomyocyte survival as a target for molecular intervention in septic cardiomyopathy. Animal experiments showed that curcumin reduced inflammation levels, improved cardiac function and increased survival in rats with septic myocardial injury. Cellular experiments showed that curcumin increased the survival rate of lipopolysaccharide-treated cardiomyocytes and down regulated TLR1 expression and inhibited NF-κB phosphorylation in cells in a dose-dependent manner. Molecular docking analysis revealed that curcumin interacted with TLR1 by hydrogen bonding and could be stably bound to inhibit the biological function of TLR1.

CONCLUSION

Our study shows that curcumin attenuates myocardial injury in sepsis by inhibiting TLR1 expression, which provides a molecular theoretical basis for clinical treatment.

Whole transcriptome analysis to explore the impaired immunological features in critically ill elderly patients with sepsis

BACKGROUND

Sepsis is a frequent complication in critically ill patients, is highly heterogeneous and is associated with high morbidity and mortality rates, especially in the elderly population. Utilizing RNA sequencing (RNA-Seq) to analyze biological pathways is widely used in clinical and molecular genetic studies, but studies in elderly patients with sepsis are still lacking. Hence, we investigated the mortality-relevant biological features and transcriptomic features in elderly patients who were admitted to the intensive care unit (ICU) for sepsis.

METHODS

We enrolled 37 elderly patients with sepsis from the ICU at Taichung Veterans General Hospital. On day-1 and day-8, clinical and laboratory data, as well as blood samples, were collected for RNA-Seq analysis. We identified the dynamic transcriptome and enriched pathways of differentially expressed genes between day-8 and day-1 through DVID enrichment analysis and Gene Set Enrichment Analysis. Then, the diversity of the T cell repertoire was analyzed with MiXCR.

RESULTS

Overall, 37 patients had sepsis, and responders and non-responders were grouped through principal component analysis. Significantly higher SOFA scores at day-7, longer ventilator days, ICU lengths of stay and hospital mortality were found in the non-responder group, than in the responder group. On day-8 in elderly ICU patients with sepsis, genes related to innate immunity and inflammation, such as ZDHCC19, ALOX15, FCER1A, HDC, PRSS33, and PCSK9, were upregulated. The differentially expressed genes (DEGs) were enriched in the regulation of transcription, adaptive immune response, immunoglobulin production, negative regulation of transcription, and immune response. Moreover, there was a higher diversity of T-cell receptors on day-8 in the responder group, than on day-1, indicating that they had better regulated recovery from sepsis compared with the non-response patients.

CONCLUSION

Sepsis mortality and incidence were both high in elderly individuals. We identified mortality-relevant biological features and transcriptomic features with functional pathway and MiXCR analyses based on RNA-Seq data; and found that the responder group had upregulated innate immunity and increased T cell diversity; compared with the non-responder group. RNA-Seq may be able to offer additional complementary information for the accurate and early prediction of treatment outcome.

Ex vivo LPS-stimulated cytokine production is associated with hydration status in community-dwelling middle-to-older-aged adults

PURPOSE

Suboptimal hydration has been linked to a variety of adverse health outcomes. Few studies have examined the impact of hydration status on immune function, a plausible physiological mechanism underlying these associations. Therefore, we tested how variation in hydration status was associated with circulating pro-inflammatory cytokine levels and ex vivo lipopolysaccharide (LPS)-stimulated pro-inflammatory cytokine production.

METHODS

Blood samples were obtained from a community sample of healthy middle-to-older-aged adults (N = 72). These samples were used to assess serum osmolality, a biomarker of hydration status, and markers of immune function including circulating pro-inflammatory cytokines and stimulated pro-inflammatory cytokine production after 4 and 24 h of incubation with LPS. Multiple linear regressions were used to test the association between serum osmolality (as a continuous variable) and markers of immune function at baseline and after 4 and 24 h adjusting for age, sex, and BMI. These models were re-estimated with serum osmolality dichotomized at the cut-off for dehydration (> 300 mOsm/kg).

RESULTS

While not significantly associated with circulating cytokines (B = - 0.03, p = 0.09), serum osmolality was negatively associated with both 4 h (B = - 0.05, p = 0.048) and 24 h (B = - 0.05, p = 0.03) stimulated cytokine production when controlling for age, sex, and BMI. Similarly, dehydration was associated with significantly lower cytokine production at both 4 h (B = - 0.54, p = 0.02) and 24 h (B = - 0.51, p = 0.02) compared to adequate hydration.

CONCLUSION

These findings suggest that dehydration may be associated with suppressed immune function in generally healthy middle-to-older aged community-dwelling adults. Further longitudinal research is needed to more clearly define the role of hydration in immune function.

Advancing personalized medicine for tuberculosis through the application of immune profiling

While early and precise diagnosis is the key to eliminating tuberculosis (TB), conventional methods using culture conversion or sputum smear microscopy have failed to meet demand. This is especially true in high-epidemic developing countries and during pandemic-associated social restrictions. Suboptimal biomarkers have restricted the improvement of TB management and eradication strategies. Therefore, the research and development of new affordable and accessible methods are required. Following the emergence of many high-throughput quantification TB studies, immunomics has the advantages of directly targeting responsive immune molecules and significantly simplifying workloads. In particular, immune profiling has been demonstrated to be a versatile tool that potentially unlocks many options for application in TB management. Herein, we review the current approaches for TB control with regard to the potentials and limitations of immunomics. Multiple directions are also proposed to hopefully unleash immunomics' potential in TB research, not least in revealing representative immune biomarkers to correctly diagnose TB. The immune profiles of patients can be valuable covariates for model-informed precision dosing-based treatment monitoring, prediction of outcome, and the optimal dose prediction of anti-TB drugs.

Preventative Management of Sepsis-Induced Acute Respiratory Distress Syndrome in the Geriatric Population

Sepsis and its treatment are the most common etiologies of acute respiratory distress syndrome (ARDS), which has a disturbing mortality rate. Sepsis management relies heavily on the introduction of resuscitative fluids. However, when fluids are paired with the circulating inflammatory mediators of sepsis, patients are prone to lung damage. Survivors of sepsis-induced ARDS become plagued with functional and/or psychological sequelae such as impaired memory, difficulty in concentrating, and decreased mental processing speed. Specific techniques can be implemented when diagnosing and treating elderly patients with sepsis to prevent the onset of ARDS, including bed elevation and early antibiotics. Additionally, albumin infusion may be beneficial; however, more research must be conducted. Finally, inflammatory mediators, including serum mannose biomarkers and extracellular histone therapy, show a promising avenue for future treatment. Although there is limited research on osteopathic manipulative medicine (OMT) on ARDS or sepsis-induced ARDS, OMT that focuses on alleviating rib and thoracic somatic dysfunctions has been used as an adjunct therapy to treat other respiratory diseases, such as pneumonia and chronic obstructive pulmonary disease (COPD). The results of these studies may garner interest in whether the use of OMT as an adjunct therapy may be beneficial for patients with ARDS or sepsis-induced ARDS. This paper is intended to review the current guidelines for sepsis and ARDS management in elderly patients to identify measures to prevent sepsis-induced ARDS.

Nutritional indices may have prognostic value in elderly critically ill patients with sepsis

Aim: Nutritional indicators are associated with adverse outcomes in critically ill elderly patients. In this study, we aimed to evaluate the prognostic potential of prealbumin and albumin in the prediction of mortality in elderly patients with sepsis. Material and Method: A total of 108 patients who developed intensive care unit-acquired sepsis were divided into two groups: Survivors (n=72) and Non-survivors (n=36). Results: Patients in the Non-survivors group were often older (68 vs 74) and presented lower prealbumin (15.1 vs 11), and higher Charlson index (4 vs 6), Sequential Organ Failure Assessment (SOFA) score (8.5 vs 10), C-reactive protein (CRP) (68.8 vs 91) and procalcitonin (PCT) (6 vs 8.4) (p< 0.05). The area under the curve of PCT was the highest at 0.74. Prealbumin presented the best sensitivity (75%) and 12 mg/dL cut-off value, while PCT had the best specificity (75%) and a cut-off value of 7 ng/mL. Although prealbumin was negatively correlated to SOFA score in a significant way (r=-0.226, p=0.019), White blood cells, CRP, and PCT were positively correlated to SOFA score (r=0.198, p=0.040; r=0.233, p=0.015; r=0.286, p=0.003, respectively). In addition, a weak negative correlation was observed between prealbumin and CRP and PCT (r=-0.203, p=0.037; r=-0.215, p=0.026, respectively). Multivariate analysis showed that a reduction in serum prealbumin levels compared to steady prealbumin greater than 4 mg/dL increased the risk of death by 85% (aHR: 1.85, 95% CI: 1.05-2.56, p=0.029). Conclusion: Changes in serum prealbumin in the acute phase of sepsis may assist in determining the risk of mortality and in the administration of specific treatment in critically ill elderly patients.

How Effective is Angiotensin II in Decreasing Mortality of Vasodilatory Shock? A Systematic Review

Background

Patients with severe vasodilation accompanied by refractory hypotension despite high doses of vasopressors were associated with a high mortality rate. The Ang-2 for the Treatment of High-Output Shock (ATHOS) 3 trial demonstrated that angiotensin 2 (Ang-2) could effectively increase MAP and blood pressure in vasodilatory shock patients. This systematic review aims to summarize the impact of Ang-2 for the treatment of vasodilatory shock on clinical outcomes, including length of stay, MAP level (before and after), and mortality also Ang-2 dose needed.

Methods

A systematic search in PubMed, Sage, ScienceDirect, Scopus and Gray literature was conducted to obtain studies about the use of Ang-2 in vasodilatory shock patients.

Results

In all of the studies that we obtained, there were different results regarding mortality in patients with vasodilatory shock with Ang-2. Mortality was significantly lower when Ang-2 was administered to patients with elevated renin. The initial dose of Ang-2 can be started at 10-20 ng/kg/min, but there is no agreement on the maximum dose. Ang-2 may be considered a third-line vasopressor if the targeted MAP has not been achieved after administration of norepinephrine >200 ng/kg/min for more than 6 hours. Although not statistically significant, the use of Ang-2 can reduce the length of stay in the ICU and in the hospital when compared to patients without Ang-2 therapy, in addition to reducing the dose of vasopressor.

Conclusion

Overall, the use of Ang-2 has potential to be a regimen for patients with vasodilatory shock. Further study is needed to obtain more data.

Prediction of short-term mortality in elderly patients with sepsis using immunoglobulin G2: An observational study

Background

Sepsis is a global healthcare issue and continues to cause high mortality especially in elderly patients. The humoral immune system plays an important role in protecting from microbial contamination. The goal of this study is to investigate the immune status and prognostic evaluation of elderly patients with sepsis.

Methods

A single-center, prospective observational study has been conducted, with the endpoint being the 28-day mortality. Patients 65 years and older who met the diagnostic criteria of Sepsis-3 in the Emergency Department of Beijing Chao-Yang Hospital were divided into survivors and non-survivors groups. Levels of immunoglobulin (Ig) A, IgG, IgM and their subclasses as well as clinical indicators were collected upon enrollment, and the results were statistically analyzed.

Results

This study finally enrolled 106 elderly patients, including 68 survivors and 38 non-survivors. Compared with survivors, IgG2 level and IgG4 level were lower in non-survivors ( P < 0.05 ). IgG2 could be regarded as an independent predictor of the 28-day mortality in elderly septic patients. IgG2 had a higher predictive value than other immunoglobulins, lactate, procalcitonin, SOFA score and APACHE II score for mortality in elderly septic patients, and the ratio of IgG2 to IgG had a slightly larger area under the ROC curve compared to IgG2 only (AUC: 0.776 v.s. 0.741).

Conclusion

IgG subclasses play important roles in the prognosis of elderly septic patients, with IgG2 being the main component. IgG2 was found to outperform other immunoglobulins, lactate, procalcitonin, SOFA score and APACHE II score in terms of predicting the mortality. A complete immunological evaluation is helpful to guide the prognosis and treatment of patients with age-related infection.

Interpretable Machine Learning to Optimize Early In-Hospital Mortality Prediction for Elderly Patients with Sepsis: A Discovery Study

Sepsis-related mortality rates are high among elderly patients, especially those in intensive care units (ICUs). Early prediction of the prognosis of sepsis is critical, as prompt and effective treatment can improve prognosis. Researchers have predicted mortality and the development of sepsis using machine learning algorithms; however, few studies specifically focus on elderly patients with sepsis. This paper proposes a viable model for early prediction of in-hospital mortality among elderly patients diagnosed with sepsis. We extracted patient information from the Medical Information Mart for Intensive Care IV database. We employed several machine learning algorithms to predict the in-hospital mortality of elderly ICU patients with sepsis. The performance of the model was evaluated by using the AUROC and F1 score. Furthermore, the SHAP algorithm was used to explain the model, analyze how the individual features affect the model output, and visualize the Shapley value for a single individual. Our study included 18522 elderly patients, with a mortality of 15.4%. After screening, 59 clinical variables were extracted to develop models. Feature importance analysis showed that age, PO2, RDW, SPO2, WBC, and urine output were significantly related to the in-hospital mortality. According to the results of AUROC (0.871 (95% CI: 0.854-0.888)) and F1 score (0.547 (95% CI: 0.539-0.661)) analyses, the extreme gradient boosting (XGBoost) model outperformed the other models (i.e., LGBM, LR, RF, DT, and KNN). Furthermore, SHAP force analysis illustrated how the constructed model visualized the individualized prediction of death. XGBoost machine learning framework gives good in-hospital mortality prediction of elderly patients with sepsis and can maximize prediction model accuracy. The XGBoost model could be an effective tool to assist doctors in identifying high-risk cases of in-hospital mortality among elderly patients with sepsis. This could be used to create a clinical decision support system in the future.

Association between age and the host response in critically ill patients with sepsis

BACKGROUND

The association of ageing with increased sepsis mortality is well established. Nonetheless, current investigations on the influence of age on host response aberrations are largely limited to plasma cytokine levels while neglecting other pathophysiological sepsis domains like endothelial cell activation and function, and coagulation activation. The primary objective of this study was to gain insight into the association of ageing with aberrations in key host response pathways and blood transcriptomes in sepsis.

METHODS

We analysed the clinical outcome (n = 1952), 16 plasma biomarkers providing insight in deregulation of specific pathophysiological domains (n = 899), and blood leukocyte transcriptomes (n = 488) of sepsis patients stratified according to age decades. Blood transcriptome results were validated in an independent sepsis cohort and compared with healthy individuals.

RESULTS

Older age was associated with increased mortality independent of comorbidities and disease severity. Ageing was associated with lower endothelial cell activation and dysfunction, and similar inflammation and coagulation activation, despite higher disease severity scores. Blood leukocytes of patients ≥ 70 years, compared to patients < 50 years, showed decreased expression of genes involved in cytokine signaling, and innate and adaptive immunity, and increased expression of genes involved in hemostasis and endothelial cell activation. The diminished expression of gene pathways related to innate immunity and cytokine signaling in subjects ≥ 70 years was sepsis-induced, as healthy subjects ≥ 70 years showed enhanced expression of these pathways compared to healthy individuals < 50 years.

CONCLUSIONS

This study provides novel evidence that older age is associated with relatively mitigated sepsis-induced endothelial cell activation and dysfunction, and a blood leukocyte transcriptome signature indicating impaired innate immune and cytokine signaling. These data suggest that age should be considered in patient selection in future sepsis trials targeting the immune system and/or the endothelial cell response.

Septic Shock: Management and Outcomes

The incidence rates of sepsis and septic shock as a complication have become more common over the past several decades. With this increase, sepsis remains the most common cause of intensive care unit (ICU) admissions and one of the most mortality factors, with a huge burden on healthcare facilities. Septic shock has devastating consequences on patients' lives, including organ failures and other long-term complications. Due to its dynamic clinical presentations, guidelines and tools have been established to improve the diagnosis and management effectively. However, there is still a need for evidence-based standardized procedures for the diagnosis, treatment, and follow-up of sepsis and septic shock patients due to the inconsistency of current guidelines and studies contrasting with each other. The standardization would help physicians better manage sepsis, minimize complications and reduce mortality. Septic shock is usually challenging to manage due to its variety of clinical characteristics and physiologic dynamics, affecting the outcomes. Therefore, this review presented the available data in the literature on septic shock diagnosis, management, and prognosis to have an overview of the updated best practice approach to septic shock.

One-year hospital readmission for recurrent sepsis: associated risk factors and impact on 1-year mortality-a French nationwide study

BACKGROUND

Sepsis is a complex health condition, leading to long-term morbidity and mortality. Understanding the risk factors for recurrent sepsis, as well as its impact on mid- and long-term mortality among other risk factors, is essential to improve patient survival.

METHODS

A risk factor analysis, based on French nationwide medico-administrative data, was conducted on a cohort of patients above 15 years old, hospitalized with an incident sepsis in metropolitan France between 1st January 2018 and 31st December 2018 and who survived their index hospitalization. Two main analyses, focusing on outcomes occurring 1-year post-discharge, were conducted: a first one to assess risk factors for recurrent sepsis and a second to assess risk factors for mortality.

RESULTS

Of the 178017 patients surviving an incident sepsis episode in 2018 and included in this study, 22.3% died during the 1-year period from discharge and 73.8% had at least one hospital readmission in acute care, among which 18.1% were associated with recurrent sepsis. Patients aged between 56 and 75, patients with cancer and renal disease, with a long index hospital stay or with mediastinal or cardiac infection had the highest odds of recurrent sepsis. One-year mortality was higher for patients with hospital readmission for recurrent sepsis (aOR 2.93; 99% CI 2.78-3.09). Among all comorbidities, patients with cancer (aOR 4.35; 99% CI 4.19-4.52) and dementia (aOR 2.02; 99% CI 1.90-2.15) had the highest odds of 1-year mortality.

CONCLUSION

Hospital readmission for recurrent sepsis is one of the most important risk factors for 1-year mortality of septic patients, along with age and comorbidities. Our study suggests that recurrent sepsis, as well as modifiable or non-modifiable other risk factors identified, should be considered in order to improve patient care pathway and survival.

Massive intravascular hemolysis is an important factor in Clostridium perfringens-induced bacteremia

Clostridium perfringens bacteremia is rare but often fatal. In particular, once bacteremia with massive intravascular hemolysis (MIH) occurs, the mortality rate is extremely high. However, because of its rarity, the detailed pathophysiology of this fulminant form of bacteremia is unclear. To elucidate the detailed pathogenesis of MIH, we retrospectively reviewed the data of all patients with C. perfringens bacteremia from two university hospitals from 2000 to 2014. The medical records and laboratory data of 60 patients with bacteremia, including 6 patients with MIH and 54 patients without MIH, were analyzed. Patients with MIH had higher rates of intense pain at onset, impaired consciousness, shock at presentation, hematuria, metabolic acidosis, and gas formation than patients without MIH. The antibiotic susceptibility of the clinical isolates was not significantly different between the two groups. All patients with MIH, although treated with appropriate antimicrobial agents, died within 26 h of admission due to rapidly progressive acute lung injury or acute respiratory distress syndrome, and the median time from arrival at the hospital to death was only 4 h and 20 min. When clinicians observe intravascular hemolysis in blood samples from patients with characteristic symptoms of MIH, they should prepare for a severe disease outcome. The underlying pathophysiology of fulminant cases must be investigated.

Comparative Study of Different Diagnostic Routine Methods for the Identification of Acinetobacter radioresistens

Recent publications indicate that A. radioresistens can cause infections in humans, even though it is rarely reported in routine diagnostics. However, the fact that it is infrequently detected may be explained by the misidentification of the species by conventional methods. It is also likely that A. radioresistens is not considered clinically relevant and therefore not consistently included in diagnostic results. To elucidate the medical significance of this probably clinically underestimated bacterial species, we created a well-documented reference strain collection of 21 strains collected in routine diagnostics. For further analysis of A. radioresistens, it is essential to know which methods can be used to achieve a trustworthy identification. We, therefore, compared three methods widely used in routine diagnostics (MALDI-TOF MS, VITEK 2, and sequencing of housekeeping genes) in terms of secure and reliable identification of A. radioresistens. As reference methods, whole genome-based approaches were applied. VITEK 2 led to misidentification for four strains. However, MALDI-TOF MS and sequencing of housekeeping genes led to reliable and robust identifications.

Immunosenescence: A Critical Factor Associated With Organ Injury After Sepsis

Progressive immune dysfunction associated with aging is known as immunosenescence. The age-related deterioration of immune function is accompanied by chronic inflammation and microenvironment changes. Immunosenescence can affect both innate and acquired immunity. Sepsis is a systemic inflammatory response that affects parenchymal organs, such as the respiratory system, cardiovascular system, liver, urinary system, and central nervous system, according to the sequential organ failure assessment (SOFA). The initial immune response is characterized by an excess release of inflammatory factors, followed by persistent immune paralysis. Moreover, immunosenescence was found to complement the severity of the immune disorder following sepsis. Furthermore, the immune characteristics associated with sepsis include lymphocytopenia, thymus degeneration, and immunosuppressive cell proliferation, which are very similar to the characteristics of immunosenescence. Therefore, an in-depth understanding of immunosenescence after sepsis and its subsequent effects on the organs may contribute to the development of promising therapeutic strategies. This paper focuses on the characteristics of immunosenescence after sepsis and rigorously analyzes the possible underlying mechanism of action. Based on several recent studies, we summarized the relationship between immunosenescence and sepsis-related organs. We believe that the association between immunosenescence and parenchymal organs might be able to explain the delayed consequences associated with sepsis.

Effects of Early Initiation of High-Dose Dexamethasone Therapy on Pro-Inflammatory Cytokines and Mortality in LPS-Challenged Mice

This study aims to explore the effects of early dexamethasone therapy at low to high doses on the survival and inflammatory responses in lipopolysaccharide (LPS)-challenged mice. We performed two-series experiments to explore the impact of early dexamethasone therapy at different doses (0.5 mg/kg, 1.5 mg/kg, and 5 mg/kg; PO) on pro-inflammatory cytokine levels, including tumor necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6), as well as survival in LPS-treated mice (10 mg/kg, IP). Dexamethasone was administered daily from 24 h before and 5 days after LPS challenge. Dose-dependent improved survival was demonstrated with dexamethasone (p < 0.05). Body weight was significantly decreased within 24 h of LPS injection, with significantly greater weight loss in the dexamethasone groups (p < 0.05). Weight changes were significantly associated with the days after LPS administration (p < 0.01), but not with the dexamethasone dose (p > 0.05). Mice treated with high-dose dexamethasone (5 mg/kg) had a significantly lowered serum TNF-α (134.41 ± 15.83 vs. 408.83 ± 18.32) and IL-6 (22.08 ± 4.34 vs. 91.27 ± 8.56) compared with those without dexamethasone. This study provides essential insights that the suppression of early-phase hyperactivation of pro-inflammatory activities through the early initiation of high-dose dexamethasone therapy increases sepsis-related prognosis.

Characterization of lncRNA-Based ceRNA Network and Potential Prognostic Hub Genes for Sepsis

Objective

Sepsis is one of the most common reasons for hospitalization and in-hospital mortality each year. Noncoding RNAs have been reported not only as diagnostic and prognostic indicators but also as therapeutic targets of sepsis. Herein, we used an integrative computational approach to identify miRNA-mediated ceRNA crosstalk between lncRNAs and genes in sepsis based on the “ceRNA hypothesis” and investigated prognostic roles of hub genes in sepsis.

Methods

Two good-quality gene expression datasets with more than 10 patient samples, GSE89376 and GSE95233, were employed to obtain differentially expressed lncRNAs (DElncRNAs) and genes (DEGs) in sepsis. The DElncRNA-miRNA-DEG regulatory network was constructed using a combination of DElncRNA-miRNA pairs and miRNA-DEmRNA pairs. The protein-protein interaction (PPI) network was constructed by mapping DEGs into the STRING database to identify hub genes in sepsis. The clinical and prognostic significance of hub genes was validated in 89 patients with post-traumatic sepsis.

Results

The integrative computational approach identified 311 DEGs and 19 DElncRNAs between septic patients and healthy volunteers. Results yielded 122 downDElncRNA-miRNA-downDEG networks based on two lncRNAs, HCP5, and HOTAIRM1, and 36 upDElncRNA-miRNA-upDEG network based on BASP1-AS1. The PPI network identified serum/glucocorticoid regulated kinase 1 (SGK1), arrestin beta 1 (ARRB1), and G protein-coupled receptor 183 (GPR183) as located at the core of the network, and three of them were downregulated in sepsis. SGK1, ARRB1, and GPR183 were all involved in lncRNA HCP5-based ceRNA network. The quantitative real-time PCR revealed that the patients with post-traumatic sepsis exhibited reduced relative mRNA levels of SGK1, ARRB1, and GPR183 compared to the patients without sepsis. The nonsurvivor group, according to the 28-day mortality, showed lower relative mRNA levels of SGK1, ARRB1, and GPR183 than the survivor group. We also demonstrated reduced mRNA levels of SGK1, ARRB1, and GPR183 were associated with sepsis-related death after trauma.

Conclusion

Our integrative analysis and clinical validation suggest lncRNA HCP5-based ceRNA networks with SGK1, ARRB1, and GPR183 involved were associated with the occurrence and progression of sepsis.

Functional Flexibility of Exosomes and MicroRNAs of Intestinal Epithelial Cells in Affecting Inflammation

Intestinal epithelial cells (IECs) are a mucosal immune barrier essential to coordinate host–microbe crosstalk. Sepsis is a systemic inflammatory syndrome with dysfunction in multiple organs including the intestine whose epithelial barrier is deregulated. Thus, IECs are a main contributor to intestinal permeability and inflammation in sepsis. Exosomes emerge as a mediator of intercellular and inter-organic communications. Recently, IEC-derived exosomes and their cargoes, such as microRNAs (miRNAs), in sepsis were shown to regulate the expression of proinflammatory mediators in the inflamed gut tissues. It is a compelling hypothesis that these IEC exosomes exhibit their dynamic activity to deliver their functional miRNA cargoes to immune cells in local and distant organs to regulate proinflammatory responses and alleviate tissue injury. Also, epithelial tight junction (TJ) proteins are downregulated on gut inflammation. Some of the IEC miRNAs were reported to deteriorate the epithelial integrity by diminishing TJ expressions in intestines during sepsis and aging. Thus, it is worth revisiting and discussing the diverse functions of IEC exosomes and miRNAs in reshaping inflammations. This review includes both iterative and hypothetical statements based on current knowledge in this field.

The Impact of Age on In-Hospital Mortality in Critically Ill COVID-19 Patients: A Retrospective and Multicenter Study

Introduction: For the past two years, healthcare systems worldwide have been battling the ongoing COVID-19 pandemic. Several studies tried to find predictive factors of mortality in COVID-19 patients. We aimed to research age as a predictive factor associated with in-hospital mortality in severe and critical SARS-CoV-2 infection. Methods: Between 1 March and 20 April 2020, we conducted a multicenter and retrospective study on a cohort of severe COVID-19 patients who were all hospitalized in the Intensive Care Unit (ICU). We led our study in nine hospitals of northeast France, one of the pandemic’s epicenters in Europe. Results: The median age of our study population was 66 years (58−72 years). Mortality was 24.6% (CI 95%: 20.6−29%) in the ICU and 26.5% (CI 95%: 22.3−31%) in the hospital. Non-survivors were significantly older (69 versus 64 years, p < 0.001) than the survivors. Although a history of cardio-vascular diseases was more frequent in the non-survivor group (p = 0.015), other underlying conditions and prior level of autonomy did not differ between the two groups. On multivariable analysis, age appeared to be an interesting predictive factor of in-hospital mortality. Thus, age ranges of 65 to 74 years (OR = 2.962, CI 95%: 1.231−7.132, p = 0.015) were predictive of mortality, whereas the group of patients aged over 75 years was not (OR = 3.084, CI 95%: 0.952−9.992, p = 0.06). Similarly, all comorbidities except for immunodeficiency (OR = 4.207, CI 95%: 1.006−17.586, p = 0.049) were not predictive of mortality. Finally, survival follow-up was obtained for the study population. Conclusion: Age appears to be a relevant predictive factor of in-hospital mortality in cases of severe or critical SARS-CoV-2 infection.

Relationships Between Age, Soluble Triggering Receptor Expressed on Myeloid Cells-1 (sTREM-1), and Mortality Among Critically Ill Adults: A Cohort Study

BACKGROUND

Innate immune dysregulation may contribute to age-related differences in outcomes among critically ill adults. Soluble triggering receptor expressed on myeloid cells-1 (sTREM-1) is an important innate immune marker with prognostic value in sepsis, but age-related differences have not been studied.

METHODS

This was a prospective cohort from a large tertiary care hospital enrolling adults from both medical and trauma-surgical intensive care units (ICUs). Plasma sTREM-1 was measured in participants within 24 h of ICU admission. We analyzed associations between age (≤50 and >50 years) and sTREM-1 using linear regression. We then examined associations between sTREM-1 and both 28-day mortality and persistent organ dysfunction (defined as need for dialysis, vasopressors, or invasive mechanical ventilation) 7 days following admission using relative risk regression.

RESULTS

Of 231 critically ill adults, older patients (n = 122) had higher prevalence of chronic disease and sepsis on enrollment than younger patients, but acute illness severity was similar. Age over 50 was associated with 27% higher sTREM-1 concentrations (95% CI 6%-53%), adjusted for sex and Charlson comorbidity index (CCI). Two-fold higher sTREM-1 was associated with 2.42-fold higher risk for mortality (95% CI 1.57, 3.73) and 1.86-fold higher risk for persistent organ dysfunction (95% CI 1.45, 2.39), adjusted for sex, CCI, and age.

CONCLUSIONS

sTREM-1 was elevated among critically ill older adults, and strongly associated with both death and persistent organ dysfunction. Immune responses associated with sTREM-1 may contribute to age-related differences in ICU outcomes, warranting further study as a potential therapeutic target in older adults.

Sarcopenia and Mortality Risk of Patients with Sepsis: A Meta-Analysis

Background

The association between sarcopenia at admission and mortality in patients with sepsis has not been comprehensively evaluated. We performed a meta-analysis to systematically evaluate the above association.

Methods

This meta-analysis included relevant observational studies from Medline, Embase, and Web of Science databases. A random-effect model after incorporation of the intrastudy heterogeneity was selected to pool the results. Subgroup analyses were applied to evaluate the influences of study characteristics on relationship.

Results

Ten cohort studies including 2396 patients with sepsis were included, and 1496 (62.4%) of them had sarcopenia at presentation. Pooled results showed that compared to those without sarcopenia, septic patients with sarcopenia had a significantly increased early (in-hospital or 1-month) mortality risk (risk ration (RR): 2.14, 95% confidence interval (CI): 1.60-2.87, P < 0.001; I 2 = 46%). Subgroup analyses showed consistent association between sarcopenia and increased acute mortality risk in septic patients which were not affected by study characteristics such as study design, country of the study, clinical settings, diagnostic criteria for sepsis, age, gender of the patients, and methods for diagnosis of sarcopenia (P for all subgroup analyses >0.05). Further meta-analyses showed that sarcopenia was also associated with increased mortality risk in septic patients at 3-6 months (RR: 2.13, 95% CI: 1.58-2.89, P < 0.001; I 2 = 0%) and at 1 year (RR: 1.57, 95% CI: 1.09-2.24, P = 0.01; I 2 = 29%).

Conclusions

Current evidence suggests that sarcopenia may be a predictor of mortality in patients with sepsis.

How old is too old?: Matched analysis of geriatric patients undergoing anterior lumbar interbody fusion

STUDY DESIGN

Retrospective Review INTRODUCTION/OBJECTIVE: The aim of this study is to utilize a national database to identify how age affects patient outcomes following anterior lumbar interbody fusion (ALIF). There are no established age guidelines for the geriatric population within the spine specialty, which makes patient selection challenging. Furthermore, there are conflicting studies for the risks of performing spine surgeries in the elderly.

METHODS

A retrospective review of the Mariner Claims Database was conducted on patients who underwent a single level ALIF (CPT 22558) between 2010 and 2018. Patients were separated into three groups by age: 50-64, 65-74, and 75-84 and matched with respect to gender, smoking, and comorbidity burden. Multivariable logistic regression was used to determine the independent effect of outpatient surgery on the postoperative outcomes after adjusting for demographic factors and pertinent comorbidities. Statistical significance was set at p < 0.05.

RESULTS

The study identified 8459 matched patients (3350 50-64; 3350 65-74; and 1759 75-84). Compared with patients aged 50-64, patients aged 65-74 and 75-84 had significantly increased risks of pneumonia (65-74: OR 1.53, 95% CI 1.06-2.24, p = 0.025; 75-84: OR 1.62, 95% CI 1.07-2.42, p = 0.022), sepsis (65-74: OR 2.20, 95% CI 1.36-3.76, p = 0.002; 75-84: OR 2.42, 95% CI 1.43-4.13, p = 0.001), and major complications (65-74: OR 1.35, 95% CI 1.05-1.74, p = 0.021; 75-84: OR 1.48, 95% CI 1.11-1.95, p = 0.006) (Table 2). There were no significant differences between patients aged 65-74 and 75-84 for risks of postoperative pneumonia, sepsis, and major complications (p > 0.05). There were no differences between any groups in terms of long-term outcomes such as pseudoarthrosis, implant related complications, or reoperation (p > 0.05) (Table 3).

DISCUSSION/CONCLUSION

The study showed that those older than 65 had a significant increase in risk of pneumonia, sepsis, and major complications following ALIF. In the two cohorts above the age of 65 (65-74 and 75-84) there was no significant differences in postoperative outcomes.

LEVEL OF EVIDENCE

3.

LncRNA NEAT1 Promotes Inflammatory Response in Sepsis via the miR-31-5p/POU2F1 Axis

Sepsis is considered to be a systemic inflammatory response, which results in organ dysfunction. LncRNA nuclear-enriched abundant transcript 1 (NEAT1) involved in sepsis progression has been reported. However, the underlying mechanism of NEAT1 in sepsis-induced inflammatory response remains to be revealed. In this study, NEAT1 and POU domain class 2 transcription factor 1 (POU2F1) were highly expressed in LPS-induced septic RAW264.7 cells, opposite to miR-31-5p expression. Furthermore, we found that NEAT1 silencing inhibited LPS-induced inflammatory response and cell proliferation, and promoted cell apoptosis. Subsequently, we found that miR-31-5p interacted with NEAT1 and targeted the 3'UTR of POU2F1, and in LPS-induced RAW264.7 cells, the inhibition of NEAT1 silencing was reversed by miR-31-5p knockdown, while POU2F1 downregulation could cover the functions of miR-31-5p knockdown. In a word, this study indicates that NEAT1 inhibits the LPS-induced progression of sepsis in RAW264.7 cells by modulating miR-31-5p/POU2F1 axis, suggesting that NEAT1 will be the potential therapeutic target for sepsis.

Biomarker-Guided Individualization of Antibiotic Therapy

Treatment failure of antibiotic therapy due to insufficient efficacy or occurrence of toxicity is a major clinical challenge, and is expected to become even more urgent with the global rise of antibiotic resistance. Strategies to optimize treatment in individual patients are therefore of crucial importance. Currently, therapeutic drug monitoring plays an important role in optimizing antibiotic exposure to reduce treatment failure and toxicity. Biomarker-based strategies may be a powerful tool to further quantify and monitor antibiotic treatment response, and reduce variation in treatment response between patients. Host response biomarkers, such as CRP, procalcitonin, IL-6, and presepsin, could potentially carry significant information to be utilized for treatment individualization. To achieve this, the complex interactions among immune system, pathogen, drug, and biomarker need to be better understood and characterized. The purpose of this tutorial is to discuss the use and evidence of currently available biomarker-based approaches to inform antibiotic treatment. To this end, we also included a discussion on how treatment response biomarker data from preclinical, healthy volunteer, and patient-based studies can be further characterized using pharmacometric and system pharmacology based modeling approaches. As an illustrative example of how such modeling strategies can be used, we describe a case study in which we quantitatively characterize procalcitonin dynamics in relation to antibiotic treatments in patients with sepsis.

Pathogenic Characterization of Clostridium perfringens Strains Isolated From Patients With Massive Intravascular Hemolysis

Sepsis caused by Clostridium perfringens infection is rare but often fatal. The most serious complication leading to poor prognosis is massive intravascular hemolysis (MIH). However, the molecular mechanism underlying this fulminant form of hemolysis is unclear. In the present study, we employed 11 clinical strains isolated from patients with C. perfringens septicemia and subdivided these isolates into groups H and NH: septicemia with (n = 5) or without (n = 6) MIH, respectively. To elucidate the major pathogenic factors of MIH, biological features were compared between these groups. The isolates of two groups did not differ in growth rate, virulence-related gene expression, or phospholipase C (CPA) production. Erythrocyte hemolysis was predominantly observed in culture supernatants of the strains in group H, and the human erythrocyte hemolysis rate was significantly correlated with perfringolysin O (PFO) production. Correlations were also found among PFO production, human peripheral blood mononuclear cell (PBMC) cytotoxicity, and production of interleukin-6 (IL-6) and interleukin-8 (IL-8) by human PBMCs. Analysis of proinflammatory cytokines showed that PFO induced tumor necrosis factor-α (TNF-α), IL-5, IL-6, and IL-8 production more strongly than did CPA. PFO exerted potent cytotoxic and proinflammatory cytokine induction effects on human blood cells. PFO may be a major virulence factor of sepsis with MIH, and potent proinflammatory cytokine production induced by PFO may influence the rapid progression of this fatal disease caused by C. perfringens.

Guidelines for Point-of-Care Fluorescence Imaging for Detection of Wound Bacterial Burden Based on Delphi Consensus

Excessive levels of bacteria impede wound healing and can lead to infectious complications. Unfortunately, clinical signs and symptoms of elevated bacterial burden are often unreliable. As a result, point--of--care fluorescence imaging, used to detect critical bacterial burden in wounds, is becoming widely recognized and adopted by clinicians across the globe as an accepted and added component of wound assessment protocol. A Delphi method was employed to establish consensus guidelines describing fluorescence imaging use. A multidisciplinary panel of 32 wound experts (56% MD, 22% podiatrist, 12.5% nurses/nurse practitioners) representing multiple sites of service (e.g., hospital outpatient, inpatient, private office, long-term care) completed two rounds of online questionnaires. The Delphi included key topics, including competencies required to perform imaging, clinical indications for imaging (e.g., signs/symptoms present, procedures warranting imaging), frequency of imaging, and a clinical workflow algorithm. Describing their clinical experiences of imaging impact, >80% reported changes in treatment plans, 96% reported that imaging-informed treatment plans led to improved wound healing, 78% reported reduced rates of amputations, and 83% reported reduced rates of microbiological sampling. The guidelines provided here will help to standardize use of fluorescence imaging among wound care providers and enhance the quality of patient care.

Follicular dendritic cell dysfunction contributes to impaired antigen-specific humoral responses in sepsis-surviving mice

Sepsis survivors exhibit impaired responsiveness to antigen (Ag) challenge associated with increased mortality from infection. The contribution of follicular dendritic cells (FDCs) in the impaired humoral response in sepsis-surviving mice is investigated in this study. We demonstrated that mice subjected to sepsis from cecal ligation and puncture (CLP mice) have reduced NP-specific high-affinity class-switched Ig antibodies (Abs) compared with sham-operated control mice following immunization with the T cell-dependent Ag, NP-CGG. NP-specific germinal center (GC) B cells in CLP mice exhibited reduced TNF-α and AID mRNA expression compared with sham-operated mice. CLP mice showed a reduction in FDC clusters, a reduced binding of immune complexes on FDCs, and reduced mRNA expression of CR2, ICAM-1, VCAM-1, FcγRIIB, TNFR1, IKK2, and LTβR compared with sham-operated mice. Adoptive transfer studies showed that there was no B cell-intrinsic defect. In summary, our data suggest that the reduced Ag-specific Ab response in CLP mice is secondary to a disruption in FDC and GC B cell function.

Risk Perception of Septic Shock with Multiple Organ Failure Due to Acute Exacerbation of an Infectious Dental Disease

In general dental conditions such as dental caries and periodontal disease, a combination of adverse conditions can cause potentially life-threatening periodontal abscess. We treated a patient in whom an oral infection developed into septic shock, resulting in patient death. A 78-year-old woman experienced spontaneous pain around a moving tooth. Pus discharge was observed, the area was sterilized, and an analgesic was prescribed. A few days later, the swelling spread to the buccal region leading to difficulty while eating. Upon systemic status and blood examination at our dental hospital, depressed consciousness due to dehydration and septic shock were suspected. Oxygenation and infusion of acetate linger with antibiotics were immediately performed. Furthermore, a blood examination revealed malnutrition and a severe infection; therefore, the patient was transferred to a nearby general hospital. However, the patient died the next day because of advanced disseminated intravascular coagulation and multiple organ failure. When an oral infection is suspected in an elderly patient, antibiotics should be quickly administered, the patient’s local and systemic state should be confirmed, and sterilization should be performed daily. If no improvement is observed, medical attention should be quickly sought.

Risk Factors for 28-Day Mortality in a Surgical ICU: A Retrospective Analysis of 347 Cases

Purpose

Advances in surgical techniques and intensive care over the past decades have significantly reduced the mortality rates of critically ill surgical patients. However, evaluations of risk factors associated with mortality in surgical intensive care units (ICUs) are limited. The aim of this study was to analyze the independent risk factors for 28-day mortality of surgical ICU patients.

Patients and Methods

The clinical data of adult patients who were admitted to the surgical ICU in the First Affiliated Hospital of Xi’an Jiaotong University from June 2013 to June 2017 were collected. Univariate and multivariable logistic regression analyses were performed to examine risk factors associated with 28-day mortality.

Results

A total of 347 patients were included in this analysis. The overall 28-day mortality rate was 32.6%. The major causes of surgical ICU admission were gastrointestinal diseases (46.7%), infection (20.5%), trauma (8.9%), respiratory diseases (8.9%) and cardiovascular diseases (6.6%). The univariate analysis showed age, total bilirubin, prothrombin time, international normalized ratio, arterial lactate level, APACHE II and SOFA score at ICU admission were significantly associated with 28-day mortality. In the multivariate analysis, however, age [Odds Ratio (OR): 2.899, 95% CI: 1.427–5.890, P=0.003], hypertension [OR: 3.630, 95% CI: 1.545–8.531, P=0.003], platelet count [OR: 1.004, 95% CI: 1.001–1.007, P=0.015], arterial lactate level [OR: 1.186, 95% CI: 1.088–1.293, P<0.001] and SOFA score [OR: 1.289, 95% CI: 1.131–1.469, P<0.001] were identified as the independent risk factors for 28-day mortality of patients in the surgical ICU.

Conclusion

In patients admitted to the surgical ICU, age 65 and older, a high arterial lactate level and SOFA score at ICU admission were associated with increased 28-day mortality.

Management of Very Old Patients in Intensive Care Units

The global population is aging and the demand for critical care wards increasing. Aging is associated not only with physiological and cognitive vulnerability, but also with a decline in organ function. A new topic in geriatric care is how to appropriately use critical care resources and provide the best treatment plan for very old patients (VOPs). Our special geriatric intensive care unit has admitted nearly 500 VOPs. In this review, we share our VOP treatment strategy and summarize the key points as “ABCCDEFGHI bundles.” The aim is to help intensivists to provide more comprehensive therapy for VOPs in intensive care units.

Serratia Marcescens Endophthalmitis and Bacteraemia following Complicated Cataract Surgery

A 93-year-old male presented with left eye pain, fever and loss of vision two days after complicated cataract surgery. A diagnosis of Serratia marcescens endophthalmitis and systemic bacteremia was made after the organism was identified on vitreous and peripheral blood cultures. This case demonstrates that an aggressive intraocular infection can lead to bacteremia.

Host-virus interaction and viral evasion

With each infectious pandemic or outbreak, the medical community feels the need to revisit basic concepts of immunology to understand and overcome the difficult times brought about by these infections. Regarding viruses, they have historically been responsible for many deaths, and such a peculiarity occurs because they are known to be obligate intracellular parasites that depend upon the host's cell machinery for their replication. Successful infection with the production of essential viral components requires constant viral evolution as a strategy to manipulate the cellular environment, including host internal factors, the host's nonspecific and adaptive immune responses to viruses, the metabolic and energetic state of the infected cell, and changes in the intracellular redox environment during the viral infection cycle. Based on this knowledge, it is fundamental to develop new therapeutic strategies for controlling viral dissemination, by means of antiviral therapies, vaccines, or antioxidants, or by targeting the inhibition or activation of cell signaling pathways or metabolic pathways that are altered during infection. The rapid recovery of altered cellular homeostasis during viral infection is still a major challenge. Here, we review the strategies by which viruses evade the host's immune response and potential tools used to develop more specific antiviral therapies to cure, control, or prevent viral diseases.

Aging, Immunity, and COVID-19: How Age Influences the Host Immune Response to Coronavirus Infections?

The novel coronavirus severe acute respiratory syndrome coronavirus 2 causing the Coronavirus disease (COVID-19) pandemic has ravaged the world with over 72 million total cases and over 1.6 million deaths worldwide as of early December 2020. An overwhelming preponderance of cases and deaths is observed within the elderly population, and especially in those with pre-existing conditions and comorbidities. Aging causes numerous biological changes in the immune system, which are linked to age-related illnesses and susceptibility to infectious diseases. Age-related changes influence the host immune response and therefore not only weaken the ability to fight respiratory infections but also to mount effective responses to vaccines. Immunosenescence and inflamm-aging are considered key features of the aging immune system wherein accumulation of senescent immune cells contribute to its decline and simultaneously increased inflammatory phenotypes cause immune dysfunction. Age-related quantitative and qualitative changes in the immune system affect cells and soluble mediators of both the innate and adaptive immune responses within lymphoid and non-lymphoid peripheral tissues. These changes determine not only the susceptibility to infections, but also disease progression and clinical outcomes thereafter. Furthermore, the response to therapeutics and the immune response to vaccines are influenced by age-related changes within the immune system. Therefore, better understanding of the pathophysiology of aging and the immune response will not only help understand age-related diseases but also guide targeted management strategies for deadly infectious diseases like COVID-19.

Efficacy of blood urea nitrogen and the neutrophil-to-lymphocyte ratio as predictors of mortality among elderly patients with genitourinary tract infections: A retrospective multicentre study

OBJECTIVES

To investigate whether initial blood urea nitrogen (BUN) and the neutrophil-to-lymphocyte ratio (NLR) in the emergency department (ED) are associated with mortality in elderly patients with genitourinary tract infections.

METHODS

A total of 541 patients with genitourinary tract infections in 5 EDs between November 2016 and February 2017 were included and retrospectively reviewed. We assessed age, sex, comorbidities, vital signs, and initial laboratory results, including BUN, NLR and the SOFA criteria. The primary outcome was all-cause in-hospital mortality.

RESULTS

The nonsurvivor group included 32 (5.9%) elderly patients, and the mean arterial pressure (MAP), NLR and BUN were significantly higher in this group than in the survivor group (p < 0.001, p = 0.003, p < 0.001). In multivariate analysis, MAP <70 mmHg, NLR ≥23.8 and BUN >28 mg/dl were shown to be independent risk factors for in-hospital mortality (OR 3.62, OR 2.51, OR 2.76: p = 0.002, p = 0.033, p = 0.038, respectively). Additionally, NLR ≥23.8 and BUN >28 were shown to be independent risk factors for mortality in admitted elderly with complicated UTI (p = 0.030, p = 0.035). When BUN and NLR were combined with MAP, the area under the ROC curve (AUROC) value was 0.807 (0.771-0.839) for the prediction of mortality, the sensitivity was 87.5% (95% CI 71.0-96.5), and the specificity was 61.3% (95% CI 56.9-65.5%).

CONCLUSION

The initial BUN and NLR values with the MAP were good predictors associated with all-cause in-hospital mortality among elderly genitourinary tract infections visiting the ED.

Nutraceuticals-Based Immunotherapeutic Concepts and Opportunities for the Mitigation of Cellular Senescence and Aging: A Narrative Review

The role of increased tissue senescent cell (SC) burden in driving the process of ageing and associated disorders is rapidly gaining attention. Amongst various plausible factors, impairment in immune functions is emerging as a critical regulator of known age-associated accumulation of SC. Immune cells dysfunctions with age are multi-faceted and are uniquely attributed to the independent processes of immunosenescence and cellular senescence which may collectively impair immune system mediated clearance of SC. Moreover, being functionally and phenotypically heterogenic, immune cells are also liable to be affected by senescence microenvironment in other tissues. Therefore, strategies aimed at improving immunosenescence and cellular senescence in immune cells can have pleiotropic effects on ageing physiology including the accumulation of SC. In this regard, nutraceutical's immunomodulatory attributes are well documented which may have implications in developing nutrition-oriented immunotherapeutic approaches against SC. In particular, the three diverse sources of bioactive ingredients, viz., phytochemicals, probiotic bacteria and omega-3-fatty acids have shown promising anti-immunosenescence and anti-cellular senescence potential in immune cells influencing aging and immunity in ways beyond modest stimulation of immune responses. The present narrative review describes the preventive and therapeutic attributes of phytochemicals such as polyphenols, probiotic microbes and omega-3-fatty acids in influencing the emerging nexus of immunosenescence, cellular senescence and SC during aging. Outstanding questions and nutraceuticals-based pro-longevity and niche research areas have been deliberated. Further research using integrative approaches is recommended for developing nutrition-based holistic immunotherapeutic strategies for 'healthy ageing'.

Immunosenescence is both functional/adaptive and dysfunctional/maladaptive

Alterations in the immune system with aging are considered to underlie many age-related diseases. However, many elderly individuals remain healthy until even a very advanced age. There is also an increase in numbers of centenarians and their apparent fitness. We should therefore change our unilaterally detrimental consideration of age-related immune changes. Recent data taking into consideration the immunobiography concept may allow for meaningful distinctions among various aging trajectories. This implies that the aging immune system has a homeodynamic characteristic balanced between adaptive and maladaptive aspects. The survival and health of an individual depends from the equilibrium of this balance. In this article, we highlight which parts of the aging of the immune system may be considered adaptive in contrast to those that may be maladaptive.

Early Immunoparalysis Was Associated with Poor Prognosis in Elderly Patients with Sepsis: Secondary Analysis of the ETASS Study

Purpose

Although immune dysfunction has been investigated in adult septic patients, early immune status remains unclear. In this study, our primary aim was to assess early immune status in adult patients with sepsis stratified by age and its relevance to hospital mortality.

Patients and Methods

A post hoc analysis of a multicenter, randomized controlled trial was conducted; 273 patients whose immune status was evaluated within 48 hours after onset of sepsis were enrolled. Early immune status was evaluated by the percentage of monocyte human leukocyte antigen-DR (mHLA-DR) in total monocytes within 48 hours after onset of sepsis and it was classified as immunoparalysis (mHLA-DR ≤30%) or non-immunoparalysis (>30%). Three logistic regression models were conducted to explore the associations between early immunoparalysis and hospital mortality. We also developed two sensitivity analyses to find out whether the definition of early immune status (24 hours vs 48 hours after onset of sepsis) and immunotherapy affect the primary outcome.

Results

Of the 181 elderly (≥60yrs) and 92 non-elderly (<60yrs) septic patients, 71 (39.2%) and 25 (27.2%) died in hospital, respectively. The percentage of early immunoparalysis in the elderly was twice of that in the non-elderly patients (32% vs 16%, p=0.006). For the elderly, hospital mortality was higher in the immunoparalysis ones than the non-immunoparalysis ones (53.4% vs 32.5%, p=0.009). But there was no significant difference in hospital mortality between immunoparalysis non-elderly patients and non-immunoparalysis non-elderly ones (33.5% vs 26.0%, p=0.541). By means of logistic regression models, we found that early immunoparalysis was independently associated with increased hospital mortality in elderly, but not in non-elderly patients. Sensitivity analysis further confirmed the definition of early immune status and immunotherapy did not affect the outcomes.

Conclusion

The elderly were more susceptible to early immunoparalysis after onset of sepsis. Early immunoparalysis was independently associated with poor prognosis in elderly, but not in non-elderly patients.