Inefficient Recovery of Repeatedly Stimulated Memory CD8 T Cells after Polymicrobial Sepsis Induction Leads to Changes in Memory CD8 T Cell Pool Composition.

Long-lasting sepsis-induced immunoparalysis has been principally studied in primary (1°) memory CD8 T cells; however, the impact of sepsis on memory CD8 T cells with a history of repeated cognate Ag encounters is largely unknown but important in understanding the role of sepsis in shaping the pre-existing memory CD8 T cell compartment. Higher-order memory CD8 T cells are crucial in providing immunity against common pathogens that reinfect the host or are generated by repeated vaccination. In this study, we analyzed peripheral blood from septic patients and show that memory CD8 T cells with defined Ag specificity for recurring CMV infection proliferate less than bulk populations of central memory CD8 T cells. Using TCR-transgenic T cells to generate 1° and higher-order (quaternary [4°]) memory T cells within the same host, we demonstrate that the susceptibility and loss of both memory subsets are similar after sepsis induction, and sepsis diminished Ag-dependent and -independent (bystander) functions of these memory subsets equally. Both the 1° and 4° memory T cell populations proliferated in a sepsis-induced lymphopenic environment; however, due to the intrinsic differences in baseline proliferative capacity, expression of receptors (e.g., CD127/CD122), and responsiveness to homeostatic cytokines, 1° memory T cells become overrepresented over time in sepsis survivors. Finally, IL-7/anti-IL-7 mAb complex treatment early after sepsis induction preferentially rescued the proliferation and accumulation of 1° memory T cells, whereas recovery of 4° memory T cells was less pronounced. Thus, inefficient recovery of repeatedly stimulated memory cells after polymicrobial sepsis induction leads to changes in memory T cell pool composition, a notion with important implications in devising strategies to recover the number and function of pre-existing memory CD8 T cells in sepsis survivors.

NK Cell-Derived IL-10 Supports Host Survival during Sepsis.

The dysregulated sepsis-induced cytokine storm evoked during systemic infection consists of biphasic and interconnected pro- and anti-inflammatory responses. The contrasting inflammatory cytokine responses determine the severity of the septic event, lymphopenia, host survival, and the ensuing long-lasting immunoparalysis state. NK cells, because of their capacity to elaborate pro- (i.e., IFN-γ) and anti-inflammatory (i.e., IL-10) responses, exist at the inflection of sepsis-induced inflammatory responses. Thus, NK cell activity could be beneficial or detrimental during sepsis. In this study, we demonstrate that murine NK cells promote host survival during sepsis by limiting the scope and duration of the cytokine storm. Specifically, NK cell-derived IL-10, produced in response to IL-15, is relevant to clinical manifestations in septic patients and critical for survival during sepsis. This role of NK cells demonstrates that regulatory mechanisms of classical inflammatory cells are beneficial and critical for controlling systemic inflammation, a notion relevant for therapeutic interventions during dysregulated infection-induced inflammatory responses.

Characterization and Outcomes of Hospitalized Children With Coronavirus Disease 2019: A Report From a Multicenter, Viral Infection and Respiratory Illness Universal Study (Coronavirus Disease 2019) Registry.

OBJECTIVES: Multicenter data on the characteristics and outcomes of children hospitalized with coronavirus disease 2019 are limited. Our objective was to describe the characteristics, ICU admissions, and outcomes among children hospitalized with coronavirus disease 2019 using Society of Critical Care Medicine Discovery Viral Infection and Respiratory Illness Universal Study: Coronavirus Disease 2019 registry. DESIGN: Retrospective study. SETTING: Society of Critical Care Medicine Viral Infection and Respiratory Illness Universal Study (Coronavirus Disease 2019) registry. PATIENTS: Children (< 18 yr) hospitalized with coronavirus disease 2019 at participating hospitals from February 2020 to January 2021. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: The primary outcome was ICU admission. Secondary outcomes included hospital and ICU duration of stay and ICU, hospital, and 28-day mortality. A total of 874 children with coronavirus disease 2019 were reported to Viral Infection and Respiratory Illness Universal Study registry from 51 participating centers, majority in the United States. Median age was 8 years (interquartile range, 1.25-14 yr) with a male:female ratio of 1:2. A majority were non-Hispanic (492/874; 62.9%). Median body mass index (n = 817) was 19.4 kg/m2 (16-25.8 kg/m2), with 110 (13.4%) overweight and 300 (36.6%) obese. A majority (67%) presented with fever, and 43.2% had comorbidities. A total of 238 of 838 (28.2%) met the Centers for Disease Control and Prevention criteria for multisystem inflammatory syndrome in children, and 404 of 874 (46.2%) were admitted to the ICU. In multivariate logistic regression, age, fever, multisystem inflammatory syndrome in children, and pre-existing seizure disorder were independently associated with a greater odds of ICU admission. Hospital mortality was 16 of 874 (1.8%). Median (interquartile range) duration of ICU (n = 379) and hospital (n = 857) stay were 3.9 days (2-7.7 d) and 4 days (1.9-7.5 d), respectively. For patients with 28-day data, survival was 679 of 787, 86.3% with 13.4% lost to follow-up, and 0.3% deceased. CONCLUSIONS: In this observational, multicenter registry of children with coronavirus disease 2019, ICU admission was common. Older age, fever, multisystem inflammatory syndrome in children, and seizure disorder were independently associated with ICU admission, and mortality was lower among children than mortality reported in adults.

Admission Lymphopenia is Associated With Discharge Disposition in Blunt Chest Wall Trauma Patients.

BACKGROUND: Lymphopenia contributes to the immune suppression observed in critical illness. However, its role in the immunologic response to trauma remains unclear. Herein, we assessed whether admission lymphopenia is associated with poor outcomes in patients with blunt chest wall trauma (BCWT). METHODS: All adult patients with a Chest Abbreviated Injury Score (CAIS) ≥2 admitted to our Level I Trauma center between May 2009 and December 2018 were identified in our institution Trauma Registry. Patients with absolute lymphocyte counts (ALC) collected within 24 H of admission were included. Patients who died within 24 H of admission, had bowel perforation on admission, penetrating trauma, and burns were excluded. Demographics, injury characteristics, comorbidities, ALC, complications, and outcomes were collected. Lymphopenia was defined as an ALC ≤1000/µL. Association between lymphopenia and clinical outcomes of BCWT was assessed using multivariate analyses. P < 0.05 was considered significant. RESULTS: A total of 1394 patients were included; 69.7% were male; 44.3% were lymphopenic. On univariate analysis, lymphopenia was associated with longer in-hospital stay (11.6±10.2 versus 10.1±11.4, P = 0.009), in-hospital death (9.7% versus 5.8%, P = 0.006), and discharge to a healthcare facility (60.9% versus 46.4%, P < 0.001). Controlling for Injury Severity Score, age, gender, and comorbidities, the association between lymphopenia and discharge to another facility (SNF/rehabilitation facility/ACH) (OR = 1.380 [1.041-1.830], P = 0.025) remained significant. CONCLUSIONS: Lymphopenia on admission is associated with discharge requiring increased healthcare support. Routine lymphocyte count monitoring on admission may provide important prognostic information for BCWT patients.

Addressing Language Barriers in the Intensive Care Unit: A Case-Based Reflection and Brief Appraisal of the Literature.

At present, a substantial number of individuals in the US face limited English proficiency (LEP), posing difficulties for healthcare providers. Language barriers between healthcare providers and patients can lead to poor quality of care, especially in patients with hyperacute conditions such as stroke, myocardial infarction, acute trauma, and more. In the intensive care unit (ICU), diagnosis and rapid treatment decision-making rely on taking an accurate patient history and physical exam. While in-person interpreters are the gold standard for patients with LEP, the fast-paced nature of the ICU may require alternate modes of using interpreting services to fit ICU workflows. We present a case-based reflection of a patient with LEP who presented to our ICU after a motor vehicle accident. We present this case from the perspective of a third-year medical student caring for a patient while rotating in an ICU service. We illustrate how language interpretation impacted the patient's care. We conclude by appraising the ICU literature and providing solutions to addressing language barriers for ICU patients with LEP to deliver patient-centered, high-quality care.

Development and optimization of a diluted whole blood ELISpot assay to test immune function.

Sepsis remains a leading cause of death worldwide with no proven immunomodulatory therapies. Stratifying Patient Immune Endotypes in Sepsis ('SPIES') is a prospective, multicenter observational study testing the utility of ELISpot as a functional bioassay specifically measuring cytokine-producing cells after stimulation to identify the immunosuppressed endotype, predict clinical outcomes in septic patients, and test potential immune stimulants for clinical development. Most ELISpot protocols call for the isolation of PBMC prior to their inclusion in the assay. In contrast, we developed a diluted whole blood (DWB) ELISpot protocol that has been validated across multiple laboratories. Heparinized whole blood was collected from healthy donors and septic patients and tested under different stimulation conditions to evaluate the impact of blood dilution, stimulant concentration, blood storage, and length of stimulation on ex vivo IFNγ and TNFα production as measured by ELISpot. We demonstrate a dynamic range of whole blood dilutions that give a robust ex vivo cytokine response to stimuli. Additionally, a wide range of stimulant concentrations can be utilized to induce cytokine production. Further modifications demonstrate anticoagulated whole blood can be stored up to 24 h at room temperature without losing significant functionality. Finally, we show ex vivo stimulation can be as brief as 4 h allowing for a substantial decrease in processing time. The data demonstrate the feasibility of using ELISpot to measure the functional capacity of cells within DWB under a variety of stimulation conditions to inform clinicians on the extent of immune dysregulation in septic patients.

Adverse outcomes and an immunosuppressed endotype in septic patients with reduced IFN-γ ELISpot.

BACKGROUNDSepsis remains a major clinical challenge for which successful treatment requires greater precision in identifying patients at increased risk of adverse outcomes requiring different therapeutic approaches. Predicting clinical outcomes and immunological endotyping of septic patients generally relies on using blood protein or mRNA biomarkers, or static cell phenotyping. Here, we sought to determine whether functional immune responsiveness would yield improved precision.METHODSAn ex vivo whole-blood enzyme-linked immunosorbent spot (ELISpot) assay for cellular production of interferon γ (IFN-γ) was evaluated in 107 septic and 68 nonseptic patients from 5 academic health centers using blood samples collected on days 1, 4, and 7 following ICU admission.RESULTSCompared with 46 healthy participants, unstimulated and stimulated whole-blood IFN-γ expression was either increased or unchanged, respectively, in septic and nonseptic ICU patients. However, in septic patients who did not survive 180 days, stimulated whole-blood IFN-γ expression was significantly reduced on ICU days 1, 4, and 7 (all P < 0.05), due to both significant reductions in total number of IFN-γ-producing cells and amount of IFN-γ produced per cell (all P < 0.05). Importantly, IFN-γ total expression on days 1 and 4 after admission could discriminate 180-day mortality better than absolute lymphocyte count (ALC), IL-6, and procalcitonin. Septic patients with low IFN-γ expression were older and had lower ALCs and higher soluble PD-L1 and IL-10 concentrations, consistent with an immunosuppressed endotype.CONCLUSIONSA whole-blood IFN-γ ELISpot assay can both identify septic patients at increased risk of late mortality and identify immunosuppressed septic patients.TRIAL REGISTRYN/A.FUNDINGThis prospective, observational, multicenter clinical study was directly supported by National Institute of General Medical Sciences grant R01 GM-139046, including a supplement (R01 GM-139046-03S1) from 2022 to 2024.

Adverse Long-Term Outcomes and an Immune Suppressed Endotype in Sepsis Patients with Reduced Interferon-γELISpot: A Multicenter, Prospective Observational Study.

BACKGROUND: Sepsis remains a major clinical challenge for which successful treatment requires greater precision in identifying patients at increased risk of adverse outcomes requiring different therapeutic approaches. Predicting clinical outcomes and immunological endotyping of septic patients has generally relied on using blood protein or mRNA biomarkers, or static cell phenotyping. Here, we sought to determine whether functional immune responsiveness would yield improved precision. METHODS: An ex vivo whole blood enzyme-linked immunosorbent (ELISpot) assay for cellular production of interferon-γ (IFN-γ) was evaluated in 107 septic and 68 non-septic patients from five academic health centers using blood samples collected on days 1, 4 and 7 following ICU admission. RESULTS: Compared with 46 healthy subjects, unstimulated and stimulated whole blood IFNγ expression were either increased or unchanged, respectively, in septic and nonseptic ICU patients. However, in septic patients who did not survive 180 days, stimulated whole blood IFNγ expression was significantly reduced on ICU days 1, 4 and 7 (all p<0.05), due to both significant reductions in total number of IFNγ producing cells and amount of IFNγ produced per cell (all p<0.05). Importantly, IFNγ total expression on day 1 and 4 after admission could discriminate 180-day mortality better than absolute lymphocyte count (ALC), IL-6 and procalcitonin. Septic patients with low IFNγ expression were older and had lower ALC and higher sPD-L1 and IL-10 concentrations, consistent with an immune suppressed endotype. CONCLUSIONS: A whole blood IFNγ ELISpot assay can both identify septic patients at increased risk of late mortality, and identify immune-suppressed, sepsis patients.

Trial Participation and Outcomes Among English-Speaking and Spanish-Speaking Patients With Appendicitis Randomized to Antibiotics: A Secondary Analysis of the CODA Randomized Clinical Trial.

Importance: Spanish-speaking participants are underrepresented in clinical trials, limiting study generalizability and contributing to ongoing health inequity. The Comparison of Outcomes of Antibiotic Drugs and Appendectomy (CODA) trial intentionally included Spanish-speaking participants. Objective: To describe trial participation and compare clinical and patient-reported outcomes among Spanish-speaking and English-speaking participants with acute appendicitis randomized to antibiotics. Design, Setting, and Participants: This study is a secondary analysis of the CODA trial, a pragmatic randomized trial comparing antibiotic therapy with appendectomy in adult patients with imaging-confirmed appendicitis enrolled at 25 centers across the US from May 1, 2016, to February 28, 2020. The trial was conducted in English and Spanish. All 776 participants randomized to antibiotics are included in this analysis. The data were analyzed from November 15, 2021, through August 24, 2022. Intervention: Randomization to a 10-day course of antibiotics or appendectomy. Main Outcomes and Measures: Trial participation, European Quality of Life-5 Dimensions (EQ-5D) questionnaire scores (higher scores indicating a better health status), rate of appendectomy, treatment satisfaction, decisional regret, and days of work missed. Outcomes are also reported for a subset of participants that were recruited from the 5 sites with a large proportion of Spanish-speaking participants. Results: Among eligible patients 476 of 1050 Spanish speakers (45%) and 1076 of 3982 of English speakers (27%) consented, comprising the 1552 participants who underwent 1:1 randomization (mean age, 38.0 years; 976 male [63%]). Of the 776 participants randomized to antibiotics, 238 were Spanish speaking (31%). Among Spanish speakers randomized to antibiotics, the rate of appendectomy was 22% (95% CI, 17%-28%) at 30 days and 45% (95% CI, 38%-52%) at 1 year, while in English speakers, these rates were 20% (95% CI, 16%-23%) at 30 days and 42% (95% CI 38%-47%) at 1 year. Mean EQ-5D scores were 0.93 (95% CI, 0.92-0.95) among Spanish speakers and 0.92 (95% CI, 0.91-0.93) among English speakers. Symptom resolution at 30 days was reported by 68% (95% CI, 61%-74%) of Spanish speakers and 69% (95% CI, 64%-73%) of English speakers. Spanish speakers missed 6.69 (95% CI, 5.51-7.87) days of work on average, while English speakers missed 3.76 (95% CI, 3.20-4.32) days. Presentation to the emergency department or urgent care, hospitalization, treatment dissatisfaction, and decisional regret were low for both groups. Conclusions and Relevance: A high proportion of Spanish speakers participated in the CODA trial. Clinical and most patient-reported outcomes were similar for English- and Spanish-speaking participants treated with antibiotics. Spanish speakers reported more days of missed work. Trial Registration: ClinicalTrials.gov Identifier: NCT02800785.

Admission Lymphopenia Predicts Infectious Complications and Mortality in Traumatic Brain Injury Victims.

BACKGROUND: Traumatic brain injury (TBI) is a major cause of mortality and disability associated with increased risk of secondary infections. Identifying a readily available biomarker may help direct TBI patient care. Herein, we evaluated whether admission lymphopenia could predict outcomes of TBI patients. METHODS: This is a 10-year retrospective review of TBI patients with a head Abbreviated Injury Score 2 to 6 and absolute lymphocyte counts (ALC) collected within 24 h of admission. Exclusion criteria were death within 24 h of admission and presence of bowel perforation on admission. Demographics, admission data, injury severity score, mechanism of injury, and outcomes were collected. Association between baseline variables and outcomes was analyzed. RESULTS: We included 2,570 patients; 946 (36.8%) presented an ALC ≤1,000 on admission (lymphopenic group). Lymphopenic patients were significantly older, less likely to smoke, and more likely to have heart failure, hypertension, or chronic kidney disease. Lymphopenia was associated with increased risks of mortality (OR = 1.903 [1.389-2.608]; P < 0.001) and pneumonia (OR = 1.510 [1.081-2.111]; P = 0.016), increased LOS (OR = 1.337 [1.217-1.469]; P < 0.001), and likelihood of requiring additional healthcare resources at discharge (OR = 1.669 [1.344-2.073], P < 0.001). Additionally, lymphopenia increased the risk of early in-hospital death (OR = 1.459 [1.097-1.941]; P = 0.009). Subgroup analysis showed that lymphopenia was associated with mortality in polytrauma patients and those who presented with two or more concurrent types of TBI. In all subgroup analyses, lymphopenia was associated with longer length of stay and discharge requiring higher level of care. CONCLUSION: A routine complete blood count with differential for all TBI patients may help predict patient outcomes and direct care accordingly.

Phorbol ester-induced human cytomegalovirus major immediate-early (MIE) enhancer activation through PKC-delta, CREB, and NF-kappaB desilences MIE gene expression in quiescently infected human pluripotent NTera2 cells.

The ways in which human cytomegalovirus (HCMV) major immediate-early (MIE) gene expression breaks silence from latency to initiate the viral replicative cycle are poorly understood. A delineation of the signaling cascades that desilence the HCMV MIE genes during viral quiescence in the human pluripotent N-Tera2 (NT2) cell model provides insight into the molecular mechanisms underlying HCMV reactivation. In this model, we show that phorbol 12-myristate 13-acetate (PMA) immediately activates the expression of HCMV MIE RNA and protein and greatly increases the MIE-positive (MIE(+)) NT2 cell population density; levels of Oct4 (pluripotent cell marker) and HCMV genome penetration are unchanged. Decreasing PKC-delta activity (pharmacological, dominant-negative, or RNA interference [RNAi] method) attenuates PMA-activated MIE gene expression. MIE gene activation coincides with PKC-delta Thr505 phosphorylation. Mutations in MIE enhancer binding sites for either CREB (cyclic AMP [cAMP] response element [CRE]) or NF-kappaB (kappaB) partially block PMA-activated MIE gene expression; the ETS binding site is negligibly involved, and kappaB does not confer MIE gene activation by vasoactive intestinal peptide (VIP). The PMA response is also partially attenuated by the RNAi-mediated depletion of the CREB or NF-kappaB subunit RelA or p50; it is not diminished by TORC2 knockdown or accompanied by TORC2 dephosphorylation. Mutations in both CRE and kappaB fully abolish PMA-activated MIE gene expression. Thus, PMA stimulates a PKC-delta-dependent, TORC2-independent signaling cascade that acts through cellular CREB and NF-kappaB, as well as their cognate binding sites in the MIE enhancer, to immediately desilence HCMV MIE genes. This signaling cascade is distinctly different from that elicited by VIP.

Unanticipated Admission Following Outpatient Laparoscopic Cholecystectomy: Identifying Opportunities for Improvement.

BACKGROUND: Unanticipated admissions are a burden to the health care system. Over 400 000 outpatient laparoscopic cholecystectomies (LCs) are performed annually in the United States. The aim of this study is to identify causes of unanticipated admissions and modifiable risk factors. METHODS: Patients undergoing elective outpatient LCs were identified from the 2013-2015 American College of Surgeons National Surgical Quality Improvement Program database. RESULTS: A total of 69 376 patients underwent outpatient LC or LC+ intraoperative cholangiogram (IOC); 2027 (2.9%) were admitted after a median of 5 days (interquartile range 3-8). Admission rates varied by preoperative indications: pancreatitis (4.9%), gallstones with obstruction (3.9%), cholecystitis (3.0%), and gallstones without obstruction (2.6%) (P = .003). The most frequent causes were infection, retained stones, and other GI complications. Patients admitted for infection or cardiopulmonary complications were older with higher American Society of Anesthesiologists (ASA) (P < .01), while patients with pain and retained stones were younger with lower ASA (P < .01). Patients who underwent LC+IOC had a lower admission rate due to retained stones (.17% vs. .31% LC, P = .006). CONCLUSIONS: Unanticipated admissions following outpatient LC occur infrequently for diverse reasons usually within the first week after surgery. Associated factors are patient and disease related and not at all modifiable. In selected patients, increased IOC use may decrease admissions from retained stones.

Autoimmunity Increases Susceptibility to and Mortality from Sepsis.

We recently demonstrated how sepsis influences the subsequent development of experimental autoimmune encephalomyelitis (EAE) presented a conceptual advance in understanding the postsepsis chronic immunoparalysis state. However, the reverse scenario (autoimmunity prior to sepsis) defines a high-risk patient population whose susceptibility to sepsis remains poorly defined. In this study, we present a retrospective analysis of University of Iowa Hospital and Clinics patients demonstrating increased sepsis prevalence among multiple sclerosis (MS), relative to non-MS, patients. To interrogate how autoimmune disease influences host susceptibility to sepsis, well-established murine models of MS and sepsis and EAE and cecal ligation and puncture, respectively, were used. EAE, relative to non-EAE, mice were highly susceptible to sepsis-induced mortality with elevated cytokine storms. These results were further recapitulated in LPS and Streptococcus pneumoniae sepsis models. This work highlights both the relevance of identifying highly susceptible patient populations and expands the growing body of literature that host immune status at the time of septic insult is a potent mortality determinant.

Prolonged Reactive Oxygen Species Production following Septic Insult.

The dysregulated host response and organ damage following systemic infection that characterizes a septic event predisposes individuals to a chronic immunoparalysis state associated with severe transient lymphopenia and diminished lymphocyte function, thereby reducing long-term patient survival and quality of life. Recently, we observed lasting production of reactive oxygen species (ROS) in mice that survive sepsis. ROS production is a potent mechanism for targeting infection, but excessive ROS production can prove maladaptive by causing organ damage, impairing lymphocyte function, and promoting inflammaging, concepts paralleling sepsis-induced immunoparalysis. Notably, we observed an increased frequency of ROS-producing immature monocytes in septic hosts that was sustained for greater than 100 days postsurgery. Recent clinical trials have explored the use of vitamin C, a potent antioxidant, for treating septic patients. We observed that therapeutic vitamin C administration for sepsis limited ROS production by monocytes and reduced disease severity. Importantly, we also observed increased ROS production by immature monocytes in septic patients both at admission and ∼28 days later, suggesting a durable and conserved feature that may influence the host immune response. Thus, lasting ROS production by immature monocytes is present in septic patients, and early intervention strategies to reduce it may improve host outcomes, potentially reducing sepsis-induced immunoparalysis.

Sepsis leads to lasting changes in phenotype and function of memory CD8 T cells.

The global health burden due to sepsis and the associated cytokine storm is substantial. While early intervention has improved survival during the cytokine storm, those that survive can enter a state of chronic immunoparalysis defined by transient lymphopenia and functional deficits of surviving cells. Memory CD8 T cells provide rapid cytolysis and cytokine production following re-encounter with their cognate antigen to promote long-term immunity, and CD8 T cell impairment due to sepsis can pre-dispose individuals to re-infection. While the acute influence of sepsis on memory CD8 T cells has been characterized, if and to what extent pre-existing memory CD8 T cells recover remains unknown. Here, we observed that central memory CD8 T cells (TCM) from septic patients proliferate more than those from healthy individuals. Utilizing LCMV immune mice and a CLP model to induce sepsis, we demonstrated that TCM proliferation is associated with numerical recovery of pathogen-specific memory CD8 T cells following sepsis-induced lymphopenia. This increased proliferation leads to changes in composition of memory CD8 T cell compartment and altered tissue localization. Further, memory CD8 T cells from sepsis survivors have an altered transcriptional profile and chromatin accessibility indicating long-lasting T cell intrinsic changes. The sepsis-induced changes in the composition of the memory CD8 T cell pool and transcriptional landscape culminated in altered T cell function and reduced capacity to control L. monocytogenes infection. Thus, sepsis leads to long-term alterations in memory CD8 T cell phenotype, protective function and localization potentially changing host capacity to respond to re-infection.

A dirty cut, a nasty burn, a severe COVID infection; there are many ways for someone to develop sepsis. This life-threatening condition emerges when the immune system overreacts to a threat and ends up damaging the body. Even when patients survive, they are often left with a partially impaired immune system that cannot adequately protect against microbes and cancer; this is known as immunoparalysis. Memory CD8 T cells, a type of immune cell that is compromised by sepsis, are a long-lived population of cells that 'remember' previous infection or vaccination, and then react faster to prevent the same illness if the person ever encounters the same threat again. Yet it is unclear how exactly sepsis harms the function and representation of memory CD8 T cells, and the immune system in general. Jensen et al. investigated this question, first by showing that sepsis leads to a profound loss of memory CD8 T cells, but that surviving memory CD8 T cells multiply quickly ­ especially a subpopulation known as central memory CD8 T cells ­ to re-establish the memory CD8 T cell population. Since the central memory CD8 T cells proliferate better than the other memory T cells this alters the overall composition of the pool of memory CD8 T cells, with central memory cells becoming overrepresented. Further experiments revealed that this biasing toward central memory T cells, due to sepsis, created long-term changes in the distribution of memory CD8 T cells throughout the body. The way the genetic information of these cells was packaged had also been altered, as well as which genes were switched on or off. Overall, these changes reduced the ability of memory CD8 T cells to control infections. Together, these findings help to understand how immunoparalysis can emerge after sepsis, and what could be done to correct it. These findings could also be applied to other conditions ­ such as COVID-19 ­ which may cause similar long-term changes to the immune system.

Breaking human cytomegalovirus major immediate-early gene silence by vasoactive intestinal peptide stimulation of the protein kinase A-CREB-TORC2 signaling cascade in human pluripotent embryonal NTera2 cells.

The triggering mechanisms underlying reactivation of human cytomegalovirus (HCMV) in latently infected persons are unclear. During latency, HCMV major immediate-early (MIE) gene expression breaks silence to initiate viral reactivation. Using quiescently HCMV-infected human pluripotent embryonal NTera2 cells (NT2) to model HCMV reactivation, we show that vasoactive intestinal peptide (VIP), an immunomodulatory neuropeptide, immediately and dose-dependently (1 to 500 nM) activates HCMV MIE gene expression. This response requires the MIE enhancer cyclic AMP response elements (CRE). VIP quickly elevates CREB Ser133 and ATF-1 Ser63 phosphorylation levels, although the CREB Ser133 phosphorylation level is substantial at baseline. VIP does not change the level of HCMV genomes in nuclei, Oct4 (pluripotent cell marker), or hDaxx (cellular repressor of HCMV gene expression). VIP-activated MIE gene expression is mediated by cellular protein kinase A (PKA), CREB, and TORC2. VIP induces PKA-dependent TORC2 Ser171 dephosphorylation and nuclear entry, which likely enables MIE gene activation, as TORC2 S171A (devoid of Ser171 phosphorylation) exhibits enhanced nuclear entry and desilences the MIE genes in the absence of VIP stimulation. In conclusion, VIP stimulation of the PKA-CREB-TORC2 signaling cascade activates HCMV CRE-dependent MIE gene expression in quiescently infected NT2 cells. We speculate that neurohormonal stimulation via this signaling cascade is a possible means for reversing HCMV silence in vivo.

The Effect of Improving Basic Preventive Measures in the Perioperative Arena on Staphylococcus aureus Transmission and Surgical Site Infections: A Randomized Clinical Trial.

Importance: Surgical site infections increase patient morbidity and health care costs. The Centers for Disease Control and Prevention emphasize improved basic preventive measures to reduce bacterial transmission and infections among patients undergoing surgery. Objective: To assess whether improved basic preventive measures can reduce perioperative Staphylococcus aureus transmission and surgical site infections. Design, Setting, and Participants: This randomized clinical trial was conducted from September 20, 2018, to September 20, 2019, among 19 surgeons and their 236 associated patients at a major academic medical center with a 60-day follow-up period. Participants were a random sample of adult patients undergoing orthopedic total joint, orthopedic spine, oncologic gynecological, thoracic, general, colorectal, open vascular, plastic, or open urological surgery requiring general or regional anesthesia. Surgeons and their associated patients were randomized 1:1 via a random number generator to treatment group or to usual care. Observers were masked to patient groupings during assessment of outcome measures. Interventions: Sustained improvements in perioperative hand hygiene, vascular care, environmental cleaning, and patient decolonization efforts. Main Outcomes and Measures: Perioperative S aureus transmission assessed by the number of isolates transmitted and the incidence of transmission among patient care units (primary) and the incidence of surgical site infections (secondary). Results: Of 236 patients (156 [66.1%] women; mean [SD] age, 57 [15] years), 106 (44.9%) and 130 (55.1%) were allocated to the treatment and control groups, respectively, received the intended treatment, and were analyzed for the primary outcome. Compared with the control group, the treatment group had a reduced mean (SD) number of transmitted perioperative S aureus isolates (1.25 [2.11] vs 0.47 [1.13]; P = .002). Treatment reduced the incidence of S aureus transmission (incidence risk ratio; 0.56; 95% CI, 0.37-0.86; P = .008; with robust variance clustering by surgeon: 95% CI, 0.42-0.76; P < .001). Overall, 11 patients (4.7%) experienced surgical site infections, 10 (7.7%) in the control group and 1 (0.9%) in the treatment group. Transmission was associated with an increased risk of surgical site infection (8 of 73 patients [11.0%] with transmission vs 3 of 163 [1.8%] without; risk ratio, 5.95; 95% CI, 1.62-21.86; P = .007). Treatment reduced the risk of surgical site infection (hazard ratio, 0.12; 95% CI, 0.02-0.92; P = .04; with clustering by surgeon: 95% CI, 0.03-0.51; P = .004). Conclusions and Relevance: Improved basic preventive measures in the perioperative arena can reduce S aureus transmission and surgical site infections. Trial Registration: ClinicalTrials.gov Identifier: NCT03638947.

Subcapsular hematoma in blunt splenic injury: A significant predictor of failure of nonoperative management.

BACKGROUND: In patients with blunt splenic injury (BSI), patient selection, angiography, and embolization have contributed to low nonoperative management (NOM) failure rates. Despite these advances, some patients will fail NOM. We noted that a significant proportion of NOM failures had subcapsular hematomas (SCHs) identified on imaging. We sought to determine if there is a correlation between SCH and higher risk of NOM failure after BSI. METHODS: Our institutional trauma registry was queried for all patients with BSI during a 2-year period. Charts were reviewed to determine grade, presence of SCH, and outcome of NOM. Under current institutional protocol, all stable patients with BSI Grades III to V and those with contrast blush on computed tomography are referred for angiography and embolization. Failure of NOM was declared if splenectomy was required for bleeding after an initial plan of nonoperation. RESULTS: From May 2012 to May 2014, 312 patients with BSI were identified. A total of 253 patients (81%) underwent NOM. Overall, 15 (5.9%) failed NOM. Of those undergoing NOM, 34 had SCH and 12 failed (35.3% vs. 1.5% without SCH, p = 0.0001). Failure rates in Grades 1 to 4 were 2.3%, 3.8%, 8.8%, and 19.2%, respectively. NOM failure rates in the subset with SCH for Grades I to IV were 20%, 25%, 30.8%, and 80%, respectively. These are significantly higher than patients without SCH in Grades II to IV (0%, p = 0.003; 2.3%, p = 0.008; and 4.8%, p = 0.016) and approach significance in Grade I (1.2%, p = 0.11). There were no SCHs and no failures of NOM in Grade V injuries. CONCLUSION: The NOM failure rate of BSI patients with SCH is significantly higher than those without SCH. Patients with BSI Grades I to III slated for NOM must be observed as the failure rate approaches 30%. Splenectomy should be considered in patients with Grade IV BSI with SCH, as NOM failure rate is 80%. LEVEL OF EVIDENCE: Therapeutic study, level IV.