Male gender is associated with increased risk for postinjury pneumonia

Acute emergence of the intestinal pathobiome after postinjury pneumonia

BACKGROUND

Previous preclinical studies have demonstrated sex-specific alterations in the gut microbiome following traumatic injury or sepsis alone; however, the impact of host sex on dysbiosis in the setting of postinjury sepsis acutely is unknown. We hypothesized that multicompartmental injury with subsequent pneumonia would result in host sex-specific dysbiosis.

METHODS

Male and proestrus female Sprague-Dawley rats (n = 8/group) were subjected to either multicompartmental trauma (PT) (lung contusion, hemorrhagic shock, cecectomy, bifemoral pseudofracture), PT plus 2-hour daily restraint stress (PT/RS), PT with postinjury day 1 Pseudomonas aeruginosa pneumonia (PT-PNA), PT/RS with pneumonia (PT/RS-PNA), or naive controls. Fecal microbiome was measured on days 0 and 2 using high-throughput 16S rRNA sequencing and Quantitative Insights Into Microbial Ecology 2 bioinformatics analyses. Microbial α-diversity was assessed using Chao1 (number of different unique species) and Shannon (species richness and evenness) indices. β-diversity was assessed using principal coordinate analysis. Significance was defined as p < 0.05.

RESULTS

All groups had drastic declines in the Chao1 (α-diversity) index compared with naive controls ( p < 0.05). Groups PT-PNA and PT/RS-PNA resulted in different β-diversity arrays compared with uninfected counterparts (PT, PT/RS) ( p = 0.001). Postinjury sepsis cohorts showed a loss of commensal bacteria along with emergence of pathogenic bacteria, with blooms of Proteus in PT-PNA and Escherichia-Shigella group in PT/RS-PNA compared with other cohorts. At day 2, PT-PNA resulted in β-diversity, which was unique between males and females ( p = 0.004). Microbiome composition in PT-PNA males was dominated by Anaerostipes and Parasuterella , whereas females had increased Barnesiella and Oscillibacter . The PT/RS males had an abundance of Gastranaerophilales and Muribaculaceae .

CONCLUSION

Multicompartmental trauma complicated by sepsis significantly diminishes diversity and alters microbial composition toward a severely dysbiotic state early after injury, which varies between males and females. These findings highlight the role of sex in postinjury sepsis and the pathobiome, which may influence outcomes after severe trauma and sepsis.

EFFECT OF GENDER ON 28-DAY SURVIVAL RATES AND TRANSFUSION VOLUME IN SEVERE TRAUMA PATIENTS: A MULTICENTER OBSERVATIONAL STUDY

ABSTRACT

Background: This study clarified the relationship between sex with survival and transfusion volume in severe trauma cases. Methods: A multicenter, collaborative post hoc analysis of patients with trauma in Japan was conducted. Patients aged ≥18 years with severe trauma indicated by an Injury Severity Score (ISS) of 16 or higher were enrolled. Patients were matched and analyzed by gender based on propensity score with factors determined at the time of injury. Subgroup analysis was performed on patients younger than 50 years and older than 50 years. The significance level was defined as P < 0.05. Results: The 1,189 patients included in this registry were divided into adjusted groups of 226 male and female patients each. In the main analysis, 28-day survival rates in females were significantly higher than those in males ( P = 0.046). In the subgroup analyses, there was no statistically significant prognostic effect of gender. Secondary outcomes, including transfusion volume, showed no significant gender-based variations. Logistic regression analyses consistently demonstrated that female sex was a significant favorable prognostic factor in all ages. This was true for the over-50 group on subgroup analysis, but no significant gender-prognosis relationship was identified in the under-50 age group. High ISSs were associated with poorer outcomes across all age groups. Conclusion: In severe trauma, survival at 28 days was significantly lower in males. However, this trend was not observed in patients aged <50 years. Factors other than sex hormones may be responsible for differences in posttraumatic outcomes by gender.

Sex-related immunity: could Toll-like receptors be the answer in acute inflammatory response?

An increasing number of studies have highlighted the existence of a sex-specific immune response, wherein men experience a worse prognosis in cases of acute inflammatory diseases. Initially, this sex-dependent inflammatory response was attributed to the influence of sex hormones. However, a growing body of evidence has shifted the focus toward the influence of chromosomes rather than sex hormones in shaping these inflammatory sex disparities. Notably, certain pattern recognition receptors, such as Toll-like receptors (TLRs), and their associated immune pathways have been implicated in driving the sex-specific immune response. These receptors are encoded by genes located on the X chromosome. TLRs are pivotal components of the innate immune system, playing crucial roles in responding to infectious diseases, including bacterial and viral pathogens, as well as trauma-related conditions. Importantly, the TLR-mediated inflammatory responses, as indicated by the production of specific proteins and cytokines, exhibit discernible sex-dependent patterns. In this review, we delve into the subject of sex bias in TLR activation and explore its clinical implications relatively to both the X chromosome and the hormonal environment. The overarching objective is to enhance our understanding of the fundamental mechanisms underlying these sex differences.

Comparison of the stability of glycoprotein acetyls and high sensitivity C-reactive protein as markers of chronic inflammation

It has been suggested that glycoprotein acetyls (GlycA) better reflects chronic inflammation than high sensitivity C-reactive protein (hsCRP), but paediatric/life-course data are sparse. Using data from the Avon Longitudinal Study of Parents and Children (ALSPAC) and UK Biobank, we compared short- (over weeks) and long-term (over years) correlations of GlycA and hsCRP, cross-sectional correlations between GlycA and hsCRP, and associations of pro-inflammatory risk factors with GlycA and hsCRP across the life-course. GlycA showed high short-term (weeks) stability at 15 years (r = 0.75; 95% CI = 0.56, 0.94), 18 years (r = 0.74; 0.64, 0.85), 24 years (r = 0.74; 0.51, 0.98) and 48 years (r = 0.82 0.76, 0.86) and this was comparable to the short-term stability of hsCRP at 24 years. GlycA stability was moderate over the long-term, for example between 15 and 18 years r = 0.52; 0.47, 0.56 and between 15 and 24 years r = 0.37; 0.31, 0.44. These were larger than equivalent correlations of hsCRP. GlycA and concurrently measured hsCRP were moderately correlated at all ages, for example at 15 years (r = 0.44; 0.40, 0.48) and at 18 years (r = 0.55; 0.51, 0.59). We found similar associations of known proinflammatory factors and inflammatory diseases with GlycA and hsCRP. For example, BMI was positively associated with GlycA (mean difference in GlycA per standard deviation change in BMI = 0.08; 95% CI = 0.07, 0.10) and hsCRP (0.10; 0.08, 0.11). This study showed that GlycA has greater long-term stability than hsCRP, however associations of proinflammatory factors with GlycA and hsCRP were broadly similar.

Sex disparities in adverse outcomes after surgically managed isolated traumatic spinal injury

BACKGROUND

Traumatic spinal injury (TSI) encompasses a wide range of injuries affecting the spinal cord, nerve roots, bones, and soft tissues that result in pain, impaired mobility, paralysis, and death. There is some evidence suggesting that women may have different physiological responses to traumatic injury compared to men; therefore, this study aimed to investigate if there are any associations between sex and adverse outcomes following surgically managed isolated TSI.

METHODS

Using the 2013-2019 TQIP database, all adult patients with isolated TSI, defined as a spine AIS ≥ 2 with an AIS ≤ 1 in all other body regions, resulting from blunt force trauma requiring spinal surgery, were eligible for inclusion in the study. The association between the sex and in-hospital mortality as well as cardiopulmonary and venothromboembolic complications was determined by calculating the risk ratio (RR) after adjusting for potential confounding using inverse probability weighting.

RESULTS

A total of 43,756 patients were included. After adjusting for potential confounders, female sex was associated with a 37% lower risk of in-hospital mortality [adjusted RR (95% CI): 0.63 (0.57-0.69), p < 0.001], a 27% lower risk of myocardial infarction [adjusted RR (95% CI): 0.73 (0.56-0.95), p = 0.021], a 37% lower risk of cardiac arrest [adjusted RR (95% CI): 0.63 (0.55-0.72), p < 0.001], a 34% lower risk of deep vein thrombosis [adjusted RR (95% CI): 0.66 (0.59-0.74), p < 0.001], a 45% lower risk of pulmonary embolism [adjusted RR (95% CI): 0.55 (0.46-0.65), p < 0.001], a 36% lower risk of acute respiratory distress syndrome [adjusted RR (95% CI): 0.64 (0.54-0.76), p < 0.001], a 34% lower risk of pneumonia [adjusted RR (95% CI): 0.66 (0.60-0.72), p < 0.001], and a 22% lower risk of surgical site infection [adjusted RR (95% CI): 0.78 (0.62-0.98), p < 0.032], compared to male sex.

CONCLUSION

Female sex is associated with a significantly decreased risk of in-hospital mortality as well as cardiopulmonary and venothromboembolic complications following surgical management of traumatic spinal injuries. Further studies are needed to elucidate the cause of these differences.

Sex-related differences in extracranial complications in patients with traumatic brain injury

Background

Extracranial complications after traumatic brain injury (TBI) are common. Their influence on outcome is uncertain. Furthermore, the role of sex on the development of extracranial complications following TBI remains poorly investigated. We aimed to investigate the incidence of extracranial complications after TBI with particular focus on sex-related differences with regard to complications and their influence on outcome.

Methods

This retrospective, observational study was conducted in a level I universitary swiss trauma center. Consecutive patients with TBI admitted to the intensive care unit (ICU) between 2018 and 2021 were included. Patients' and trauma characteristics, in-hospital complications (i.e., cardiovascular, respiratory, renal, metabolic, gastrointestinal, hematological, and infectious) as well as functional outcome 3 months after trauma were analyzed. Data was dichotomized by sex or by outcome. Univariate as well as multivariate logistic regression was performed to reveal possible associations between sex, outcome and complications.

Results

Overall, 608 patients were included (male n = 447, 73.5%). Extracranial complications occurred most frequently in cardiovascular, renal, hematological and infectious systems. Men and women suffered similarly from extracranial complications. While men needed correction of coagulopathies more often (p = 0.029), women suffered more frequently from urogenital infections (p = 0.001). Similar results were found in a subgroup of patients (n = 193) with isolated TBI. A multivariate analysis did not show extracranial complications to be independent predictors of unfavorable outcome.

Conclusion

Extracranial complications following TBI occur frequently during the ICU-stay, can affect almost all organ systems but are not independent predictors of unfavorable outcome. The results suggest that sex-specific strategies for early recognition of extracranial complications might not be needed in patients with TBI.

The Lung Alveolar Cell (LAC) miRNome and Gene Expression Profile of the SP-A-KO Mice After Infection With and Without Rescue With Human Surfactant Protein-A2 (1A0)

Human surfactant protein (SP)-A1 and SP-A2 exhibit differential qualitative and quantitative effects on the alveolar macrophage (AM), including a differential impact on the AM miRNome. Moreover, SP-A rescue (treatment) of SP-A-knockout (KO) infected mice impoves survival. Here, we studied for the first time the role of exogenous SP-A protein treatment on the regulation of lung alveolar cell (LAC) miRNome, the miRNA-RNA targets, and gene expression of SP-A-KO infected mice of both sexes. Toward this, SP-A-KO mice of both sexes were infected with Klebsiella pneumoniae, and half of them were also treated with SP-A2 (1A⁰). After 6 h of infection/SP-A treatment, the expression levels and pathways of LAC miRNAs, genes, and target miRNA-mRNAs were studied in both groups. We found 1) significant differences in the LAC miRNome, genes, and miRNA-mRNA targets in terms of sex, infection, and infection plus SP-A2 (1A⁰) protein rescue; 2) an increase in the majority of miRNA-mRNA targets in both study groups in KO male vs. female mice and involvement of the miRNA-mRNA targets in pathways of inflammation, antiapoptosis, and cell cycle; 3) genes with significant changes to be involved in TP-53, tumor necrosis factor (TNF), and cell cycle signaling nodes; 4) when significant changes in the expression of molecules from all analyses (miRNAs, miRNA-mRNA targets, and genes) were considered, two signaling pathways, the TNF and cell cycle, referred to as “integrated pathways” were shown to be significant; 5) the cell cycle pathway to be present in all comparisons made. Because SP-A could be used therapeutically in pulmonary diseases, it is important to understand the molecules and pathways involved in response to an SP-A acute treatment. The information obtained contributes to this end and may help to gain insight especially in the case of infection.

Female Patients with Pneumonia on Intensive Care Unit Are under Risk of Fatal Outcome

Background and Objectives: The impact of sex on mortality in patients with pneumonia requiring intensive care unit (ICU) treatment is still a controversial discussion, with studies providing heterogeneous results. The reasons for sex differences are widespread, including hormonal, immunologic and therapeutic approaches. This study's aim was to evaluate sex-related differences in the mortality of ICU patients with pneumonia. Material and Methods: A prospective observational clinical trial was performed at Charité University Hospital in Berlin. Inclusion criteria were a diagnosis of pneumonia and a treatment period of over 24 h on ICU. A total of 436 mainly postoperative patients were included. Results: Out of 436 patients, 166 (38.1%) were female and 270 (61.9%) were male. Significant differences in their SOFA scores on admission, presence of immunosuppression and diagnosed cardiovascular disease were observed. Male patients were administered more types of antibiotics per day (p = 0.028) at significantly higher daily costs (in Euros) per applied anti-infective drug (p = 0.003). Mortalities on ICU were 34 (20.5%) in females and 39 (14.4%) in males (p = 0.113), before correcting for differences in patient characteristics using logistic regression analysis, and afterwards, the female sex showed an increased risk of ICU mortality with an OR of 1.775 (1.029-3.062, p = 0.039). Conclusions: ICU mortality was significantly higher in female patients with pneumonia. The identification of sex-specific differences is important to increase awareness among clinicians and allow resource allocation. The impact of sex on illness severity, sex differences in infectious diseases and the consequences on treatment need to be elucidated in the future.

Female hormones prevent sepsis-induced cardiac dysfunction: an experimental randomized study

Although epidemiologic research has demonstrated significant differences in incidence and outcomes of sepsis according to sex, their underlying biological mechanisms are poorly understood. Here, we studied the influence of hormonal status by comparing in vivo cardiac performances measured by MRI in non-ovariectomized and ovariectomized septic female rats. Control and ovariectomized rats were randomly allocated to the following groups: sham, sepsis and sepsis plus landiolol. Sepsis was induced by caecum ligation and punction (CLP). Landiolol, a short-acting selective β1-adrenergic blocker improving the in vivo cardiac performance of septic male rats was perfused continuously after sepsis induction. Cardiac MRI was carried out 18 h after induction of sepsis to assess in vivo cardiac function. Capillary permeability was evaluated by Evans Blue administration and measurement of its tissue extravasation. Variation in myocardial gene and protein expression was also assessed by qPCR and western-blot in the left ventricular tissue. Sepsis reduced indexed stroke volume, cardiac index and indexed end-diastolic volume compared to sham group in ovariectomized females whereas it had no effect in control females. This was associated with an overexpression of JAK2 expression and STAT3 phosphorylation on Ser727 site, and an inhibition of the adrenergic pathways in OVR females. Landiolol increased the indexed stroke volume by reversing the indexed end-diastolic volume reduction after sepsis in ovariectomized females, while it decreased indexed stroke volume and cardiac index in control. This was supported by an overexpression of genes involved in calcium influx in OVR females while an inactivation of the β-adrenergic and a calcium efflux pathway was observed in control females. Sepsis decreased in vivo cardiac performances in ovariectomized females but not in control females, presumably associated with a more pronounced inflammation, inhibition of the adrenergic pathway and calcium efflux defects. Administration of landiolol prevents this cardiac dysfunction in ovariectomized females with a probable activation of calcium influx, while it has deleterious effects in control females in which calcium efflux pathways were down-regulated.

Loss of life expectancy due to respiratory infectious diseases: findings from the global burden of disease study in 195 countries and territories 1990–2017

Understanding of the patterns of and changes in mortality from respiratory infectious diseases (RID) and its contribution to loss of life expectancy (LE) is inadequate in the existing literature. With rapid sociodemographic changes globally, and the current COVID-19 pandemic, it is timely to revisit the disease burden of RID. Using the approaches of life table and cause-eliminated life table based on data from the Global Burden of Disease Study (GBD), the study analyses loss of LE due to RID in 195 countries/territories and its changes during the period 1990–2017. Results indicate that loss of LE due to RID stood at 1.29 years globally in 2017 globally and varied widely by age, gender, and geographic location, with men, elderly people, and populations in middle/low income countries/territories suffering a disproportionately high loss of LE due to RID. Additionally, loss of LE due to RID decreased remarkably by 0.97 years globally during the period 1990–2017 but increased slightly among populations older than 70 years and in many high income countries/territories. Results suggest that RID still pose a severe threat for population and public health, and that amid dramatic sociodemographic changes globally, the disease burden of RID may resurge. The study presents the first examination of the life-shortening effect of RID at the global and country/territory levels, providing new understanding of the changing disease burden of RID and shedding light on the potential consequences of the current COVID-19 pandemic.

Diet-induced obesity in mice impairs host defense against Klebsiella pneumonia in vivo and glucose transport and bactericidal functions in neutrophils in vitro

Obesity impairs host defense against Klebsiella pneumoniae, but responsible mechanisms are incompletely understood. To determine the impact of diet-induced obesity on pulmonary host defense against K. pneumoniae, we fed 6-wk-old male C57BL/6j mice a normal diet (ND) or high-fat diet (HFD) (13% vs. 60% fat, respectively) for 16 wk. Mice were intratracheally infected with Klebsiella, assayed at 24 or 48 h for bacterial colony-forming units, lung cytokines, and leukocytes from alveolar spaces, lung parenchyma, and gonadal adipose tissue were assessed using flow cytometry. Neutrophils from uninfected mice were cultured with and without 2-deoxy-d-glucose (2-DG) and assessed for phagocytosis, killing, reactive oxygen intermediates (ROI), transport of 2-DG, and glucose transporter (GLUT1-4) transcripts, and protein expression of GLUT1 and GLUT3. HFD mice had higher lung and splenic bacterial burdens. In HFD mice, baseline lung homogenate concentrations of IL-1β, IL-6, IL-17, IFN-γ, CXCL2, and TNF-α were reduced relative to ND mice, but following infection were greater for IL-6, CCL2, CXCL2, and IL-1β (24 h only). Despite equivalent lung homogenate leukocytes, HFD mice had fewer intraalveolar neutrophils. HFD neutrophils exhibited decreased Klebsiella phagocytosis and killing and reduced ROI to heat-killed Klebsiella in vitro. 2-DG transport was lower in HFD neutrophils, with reduced GLUT1 and GLUT3 transcripts and protein (GLUT3 only). Blocking glycolysis with 2-DG impaired bacterial killing and ROI production in neutrophils from mice fed ND but not HFD. Diet-induced obesity impairs pulmonary Klebsiella clearance and augments blood dissemination by reducing neutrophil killing and ROI due to impaired glucose transport.

The Hematopoietic Stem/Progenitor Cell Response to Hemorrhage, Injury, and Sepsis: A Review of Pathophysiology

ABSTRACT

Hematopoietic stem/progenitor cells (HSPC) have both unique and common responses following hemorrhage, injury, and sepsis. HSPCs from different lineages have a distinctive response to these "stress" signals. Inflammation, via the production of inflammatory factors, including cytokines, hormones, and interferons, has been demonstrated to impact the differentiation and function of HSPCs. In response to injury, hemorrhagic shock, and sepsis, cellular phenotypic changes and altered function occur, demonstrating the rapid response and potential adaptability of bone marrow hematopoietic cells. In this review, we summarize the pathophysiology of emergency myelopoiesis and the role of myeloid-derived suppressor cells, impaired erythropoiesis, as well as the mobilization of HSPCs from the bone marrow. Finally, we discuss potential therapeutic options to optimize HSPC function after severe trauma or infection.

Prolonged Prehospital Time is a Risk Factor for Pneumonia in Trauma (the PRE-TRIP study): A Retrospective Analysis of the United States National Trauma Data Bank

BACKGROUND

Although multiple risk factors for development of pneumonia in patients with trauma sustained in a motor vehicle accident have been studied, the effect of prehospital time on pneumonia incidence post-trauma is unknown.

RESEARCH QUESTION

Is prolonged prehospital time an independent risk factor for pneumonia?

STUDY DESIGN AND METHODS

We retrospectively analyzed prospectively collected clinical data from 806,012 motor vehicle accident trauma incidents from the roughly 750 trauma hospitals contributing data to the National Trauma Data Bank between 2010 and 2016.

RESULTS

Prehospital time was independently associated with development of pneumonia post-motor vehicle trauma (p < 0.001). This association was primarily driven by patients with low Glasgow Coma Scale scores. Post-trauma pneumonia was uncommon (1.5% incidence) but was associated with a significant increase in mortality (p < 0.001, 4.3% mortality without pneumonia vs. 12.1% mortality with pneumonia). Other pneumonia risk factors included age, sex, race, primary payor, trauma center teaching status, bed size, geographic region, intoxication, comorbid lung disease, steroid use, lower Glasgow Coma Scale score, higher Injury Severity Scale score, blood product transfusion, chest trauma, and respiratory burns.

INTERPRETATION

Increased prehospital time is an independent risk factor for development of pneumonia and increased mortality in patients with trauma caused by a motor vehicle accident. Although prehospital time is often not modifiable, its recognition as a pneumonia risk factor is important as prolonged prehospital time may need to be considered in subsequent decision making.

CLINICAL TRIAL REGISTRATION

Not applicable.

A scoping review of female drowning: an underexplored issue in five high-income countries

BACKGROUND

Drowning is a significant public health issue, with females accounting for one third of global drowning deaths. The rate of female drowning has not decreased within high-income countries and presentations to hospital have increased. This scoping review aimed to explore adult female unintentional drowning, including risk factors, clinical treatment and outcomes of females hospitalised for drowning.

METHODS

A systematic search of the literature following the PRISMA-ScR framework was undertaken. The databases OVID MEDLINE, Embase, CINAHL, OVID Emcare, Web of Science, Informit and Scopus were accessed. Study locations of focus were Australia, Canada, New Zealand, the United Kingdom, and the United States. Studies from January 2003 to April 2019 were included. The quality of evidence of included studies was assessed using GRADE guidelines.

RESULTS

The final search results included 14 studies from Australia (n = 4), Canada (n = 1), New Zealand (n = 1), United States (n = 6), United Kingdom (n = 1), and one study reporting data from both Australia and United States. Nine studies reported risk factors for female drowning including age, with the proportion of female drowning incidence increasing with age. Although females are now engaging in risk-taking behaviours associated with drowning that are similar to males, such as consuming alcohol and swimming in unsafe locations, their exposure to risky situations and ways they assess risk, differ. Females are more likely to drown from accidental entry into water, such as in a vehicle during a flood or fall into water. This review found no evidence on the clinical treatment provided to females in hospital after a drowning incident, and only a small number of studies reported the clinical outcomes of females, with inconsistent results (some studies reported better and some no difference in clinical outcomes among females).

CONCLUSION

Adult females are a group vulnerable to drowning, that have lacked attention. There was no single study found which focused solely on female drowning. There is a need for further research to explore female risk factors, the clinical treatment and outcomes of females hospitalised for drowning. This will not only save the lives of females, but also contribute to an overall reduction in drowning.

Sex Differences in Respiratory Viral Pathogenesis and Treatments

Biological sex affects the outcome of diverse respiratory viral infections. The pathogenesis of respiratory infections caused by viruses ranging from respiratory syncytial virus to influenza viruses and severe acute respiratory syndrome coronavirus 2 differs between the sexes across the life course. Generally, males are more susceptible to severe outcomes from respiratory viral infections at younger and older ages. During reproductive years (i.e., after puberty and prior to menopause), females are often at greater risk than males for severe outcomes. Pregnancy and biological sex affect the pathogenesis of respiratory viral infections. In addition to sex differences in the pathogenesis of disease, there are consistent sex differences in responses to treatments, with females often developing greater immune responses but experiencing more adverse reactions than males. Animal models provide mechanistic insights into the causes of sex differences in respiratory virus pathogenesis and treatment outcomes, where available. Expected final online publication date for the Annual Review of Virology, Volume 8 is September 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

Impact of coexisting pneumonia in the patients admitted with Clostridium difficile infection: a retrospective study from a national inpatient database

Clostridium difficile is a gram-positive anaerobic spore forming bacillus that can cause infection in a setting of antibiotic use. Pneumonia is a major cause of morbidity and mortality in an inpatient setting and is frequently associated with significant antibiotic administration. This study aims to compare the outcomes of C. difficile infection (CDI) with and without pneumonia to determine the impact of pneumonia in hospitalized patients with CDI. This population-based retrospective observational propensity matched analysis study uses data from the National Inpatient Sample database for the years 2016 and 2017. The primary outcomes were in-hospital mortality, total hospital charges, and mean length of stay. Secondary outcomes were the rates of sepsis, septic shock, non-ST elevation myocardial infarction (NSTEMI), acute renal failure, deep vein thrombosis, and pulmonary embolism. In-hospital mortality was noted to be higher in patients with pneumonia than those without (6.5% vs 1.2%, adjusted OR (aOR) 3.85; 95% CI 2.90 to 5.11, p<0.001). The following outcomes were more prevalent in patients with pneumonia compared with those without pneumonia: sepsis (9.8% vs 1.8%, aOR 4.69, 95% CI 3.73 to 5.87, p<0.001), septic shock (4.0% vs 0.5%, aOR 6.32, 95% CI 4.43 to 9.03, p<0.001), NSTEMI (1.9% vs 0.5%, aOR 2.95, 95% CI 1.85 to 4.71, p<0.001), and acute renal failure (31.5% vs 23.1%, aOR 1.23, 95% CI 1.07 to 1.40, p=0.003). In conclusion, patients with pneumonia were associated with significantly higher rates of system-based complications and higher in-hospital mortality rates.

Why women have more autoimmune diseases than men: An evolutionary perspective

Women have up to a fourfold increase in risk for autoimmune disease compared to men. Many explanations have been proposed, including sex hormones, the X chromosome, microchimerism, environmental factors, and the microbiome. However, the mechanism for this autoimmune sex bias remains obscure. In this manuscript, we evaluate the hypothesis that qualitative or quantitative differences in circulating antibodies may explain, at least in part, the pathogenesis of autoimmune disease and its sex bias-especially when considering an evolutionary perspective. Indeed, women have higher absolute levels of antibodies than men, and (auto)antibodies are also associated with most autoimmune diseases. Several facts suggest differences in antibodies may cause increased prevalence of autoimmune disease in women. First, the association between increased quantities of serum antibodies and increased prevalence of autoimmunity is found not only in women, but also in men with Klinefelter syndrome. Second, both serum antibody levels and autoimmunity spike in the postpartum period. Third, a dose-response effect exists between parity and both serum antibodies and prevalence of autoimmune disease. Fourth, many biologically plausible mechanisms explain the association, such as T cell-dependent activation of B cells and/or VGLL3. The evolutionary underpinning of increased antibodies in women is likely to be protection of offspring from infections. Overall, this evolutionary paradigm can help explain why the phenomenon of autoimmunity occurs preferentially in women and raises the possibility of new treatment options.

Murine Myeloid Progenitors Attenuate Immune Dysfunction Induced by Hemorrhagic Shock

Hemorrhagic shock induces an aberrant immune response characterized by simultaneous induction of a proinflammatory state and impaired host defenses. The objective of this study was to evaluate the impact of conditionally immortalized neutrophil progenitors (NPs) on this aberrant immune response. We employed a mouse model of hemorrhagic shock, followed by the adoptive transfer of NPs and subsequent inoculation of Staphylococcus aureus to induce pneumonia. We observed that transplant of NPs decreases the proportion of host neutrophils that express programmed death ligand 1 and intercellular adhesion molecule 1 in the context of prior hemorrhage. Following hemorrhage, NP transplant decreased proinflammatory cytokines in the lungs, increased neutrophil migration into the airspaces, and enhanced bacterial clearance. Further, hemorrhagic shock improved NP engraftment in the bone marrow. These results suggest that NPs hold the potential for use as a cellular therapy in the treatment and prevention of secondary infection following hemorrhagic shock.

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Myeloid progenitors restore a competent inflammatory response to pneumonia

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Progenitor transplantation promotes clearance of secondary S. aureus pneumonia

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Hemorrhagic shock enhances engraftment of transplanted myeloid progenitors

The Diagnostic Value of Fe3+ and Inflammation Indicators in the Death of Sepsis Patients: A Retrospective Study of 428 Patients

Background

Studies have shown that a variety of blood inflammatory markers can be used to assess the criticality of patients with sepsis. In this study, the blood inflammatory factors related to the sepsis survival group and the death group were compared and analyzed, which can be used by clinicians to adjust sepsis patient treatment.

Methods

This study used retrospective methods to analyze the medical records of 428 patients with sepsis. The test of blood samples includes the patient's age, gender, hospital stays, the concentration of procalcitonin (PCT), absolute neutrophil count (ANC), absolute lymphocyte count (ALC), neutrophil-to-lymphocyte ratio (NLR), D-dimer (DD), Fe³⁺, and hemoglobin (Hb) in the venous blood of patients with sepsis. The detection of PCT methods adopts the sandwich immunofluorescence (IF). ROC curve was used for the diagnosis and analysis of various factors of sepsis.

Results

Among all the patients with sepsis, 133 patients died, with a mortality rate of 31.07%. Analysis of related inflammatory indicators and the patient's baseline parameters showed the patients age, the values of PCT, ANC, NLR, and DD in death group were statistically higher than those in survival group (all p values were <0.05). However, the concentration of Fe³⁺ and ALC show an opposite trend between the two groups. Regression analysis results showed the patient's gender, Fe³⁺, PCT, ANC, and DD are all independent prognostic factors for patients with sepsis. The results of the ROC curve of related diagnostic indicators show that DD has the best area under curve (AUC=0.700), the most sensitive index is ANC (74.44), and the most specific index is PCT (89.80). The results of the two-by-two combined diagnosis of the four indicators showed that the PCT+DD group had better AUC (0.748) and specificity (78.23), and the Fe³⁺+DD group had the best sensitivity (75.89).

Conclusion

In this study, the patient's gender and the inflammation-related markers of Fe³⁺, PCT, ANC, and DD can be used as independent risk factors affecting the prognosis of patients with sepsis. The combination of PCT+DD and Fe³⁺+DD has high diagnostic value for patients with sepsis.

Comparison of short-term surgical outcomes between men and women with breast cancer: a retrospective study using nationwide inpatient data in Japan

PURPOSE

Although long-term survival is similar between men and women, little is known about the short-term outcomes following breast cancer surgery in men. This study was performed to compare postoperative outcomes adjusted for background factors between men and women with breast cancer using a Japanese nationwide inpatient database.

METHODS

This study included 2126 men and 363,468 women who underwent surgery for stage 0-III breast cancer from July 2010 to March 2017. We generated a 1:4 matched-pair cohort matched for age, institution, and fiscal year at admission. We then conducted multivariable regression analyses to compare postoperative complications, 30-day readmission, duration of anesthesia, length of hospitalization, and total hospitalization costs between the sexes.

RESULTS

Men were older, more likely to have comorbidities and advanced cancer, and more likely to undergo total mastectomy and axillary dissection than women. There were no significant differences in postoperative complications between the sexes, but men showed a lower risk of 30-day readmission (odds ratio 0.74; 95% confidence interval [CI] 0.57-0.95), shorter duration of anesthesia (difference - 22.0 min; 95% CI - 2.1 to - 0.5), shorter length of hospitalization (difference - 1.3 days; 95% CI - 2.1 to - 0.5), and lower total hospitalization costs (difference - 506 US dollars; 95% CI - 668 to - 334) than women.

CONCLUSIONS

The matched-pair cohort analyses revealed no significant differences in postoperative complications between men and women with breast cancer. However, men showed better outcomes than women in terms of 30-day readmission, duration of anesthesia, length of hospitalization, and total hospitalization costs.

The Influence of High Flow Nasal Cannulae on the Outcomes of Severe Respiratory Disease in Children Admitted to a Regional Hospital in South Africa

In settings where access to paediatric intensive care unit (PICU) facilities is constrained and transfer capacity is limited, High Flow Nasal Cannulae (HFNC) might fill an important service gap. The aim of this study was to document the effect of HFNC on the outcomes of children admitted with severe respiratory disease at a regional hospital without a PICU in Cape Town, South Africa. It is a 4-year retrospective analysis documenting two periods of 2 years each, one before (2013-15) and one after (2016-18) the initiation of HFNC use. Patients were between the ages of 2 months and 13 years and had been admitted to a paediatric ward. Outcomes were defined by the need for transfer to a tertiary hospital, the need for invasive ventilation and death. There were 90 instances of HFNC use with a significant reduction in the number of children who were transferred (59 vs. 31), invasively ventilated (20 vs. 6, p ≤ 0.01) and who died (3 vs. 0, p = 0.02). Before HFNC implementation, there was also a significantly greater proportion of transferred children who remained on low flow nasal cannulae (15 vs. 2, p ≤ 0.001) at the tertiary hospital. Children who failed HFNC use tended to do this within a day of initiation (Median 11 vs. 60 h for success, p ≤ 0.001). There were no complications related to its use. We believe that in our setting the utilization of HFNC has helped to timeously and accurately identify children needing to be transferred and may mitigate against severe respiratory disease progression.

Healthcare-associated infection after spinal cord injury in a tertiary rehabilitation center in South Korea: a retrospective chart audit

STUDY DESIGN

A retrospective observational study.

OBJECTIVE

To identify the difference between patients with and without healthcare-associated infection (HAI) after spinal cord injury (SCI), changes in the quantity of rehabilitation after HAI, and resistance to and application of empirical antibiotics.

SETTING

University hospital-affiliated rehabilitation center.

METHODS

Altogether, 338 patients with SCI receiving inpatient rehabilitation from January 2015 to March 2018 were categorized into two groups based on the presence or absence of HAI. Demographic and clinical characteristics, amount of rehabilitation performance between before and after HAI, resistance to antibiotics, and empirical antibiotic change rates were investigated.

RESULTS

In 79 patients, 117 HAI cases occurred, with an overall incidence of 34.6%. Male sex, complete SCI, and trauma history were more frequent in the HAI group than in the non-HAI group. Length of stay (LOS) was longer at 28.9 days in the HAI group. The incidence of lower respiratory tract infections (LRIs) and urinary tract infections (UTIs) was 5.0 and 16.9%, respectively. The rehabilitation loss rates due to LRIs and UTIs were 40.0 and 20.2%, respectively, which were not statistically significant. The rates of resistance to recommended empirical antibiotics for LRIs and UTIs were 26.9-57.7% and 54.2-67.8%, respectively. The rates of empirical antibiotic changes for LRIs and UTIs were 35.3 and 43.9%, respectively.

CONCLUSIONS

HAI after SCI was more common in men, complete SCI and trauma history. LOS was prolonged in the HAI group. A quantitative reduction of rehabilitation treatment after HAI was observed, but further research is needed for validation.

Impact of Ozone, Sex, and Gonadal Hormones on Bronchoalveolar Lavage Characteristics and Survival in SP-A KO Mice Infected with Klebsiella pneumoniae

Surfactant protein A (SP-A) plays an important role in innate immunity. The sex-dependent survival of infected SP-A knockout (KO) mice has been observed. Our goal was to study the impact of ozone (O₃) and sex, as well as gonadal hormones, on the bronchoalveolar lavage (BAL) readouts and survival, respectively, of Klebsiella pneumoniae-infected SP-A KO mice. Male and female SP-A KO mice were exposed to O₃ or filtered air and infected with K. pneumoniae. We studied markers of inflammation and tissue damage at 4, 24, and 48 h, as well as the survival over 14 days, of gonadectomized (Gx) mice implanted with control pellets (CoP) or hormone (5α-dihydrotestosterone (DHT) in female gonadectomized mice (GxF) or 17β-estradiol (E₂) in male gonadectomized mice (GxM)). We observed: (1) an increase in neutrophil and macrophage inflammatory protein-2 levels as time progressed post-infection, and O₃ exposure appeared to increase this response; (2) an increase in lactate dehydrogenase, total protein, oxidized protein, and phospholipids in response to O₃ with no consistent sex differences in studied parameters; and (3) a reduction in survival of the GxM and CoP mice, the GxM and E₂ mice, and the GxF and DHT mice but not for the GxF and CoP mice after O₃. Without SP-A, (a) sex was found to have a minimal impact on BAL cellular composition and tissue damage markers, and (b) the impact of gonadal hormones on survival was found to involve different mechanisms than in the presence of SP-A.

Neuroendocrine Modulation of the Immune Response after Trauma and Sepsis: Does It Influence Outcome?

Although the treatment of multiple-injured patients has been improved during the last decades, sepsis and multiple organ failure (MOF) still remain the major cause of death. Following trauma, profound alterations of a large number of physiological systems can be observed that may potentially contribute to the development of sepsis and MOF. This includes alterations of the neuroendocrine and the immune system. A large number of studies focused on posttraumatic changes of the immune system, but the cause of posttraumatic immune disturbance remains to be established. However, an increasing number of data indicate that the bidirectional interaction between the neuroendocrine and the immune system may be an important mechanism involved in the development of sepsis and MOF. The aim of this article is to highlight the current knowledge of the neuroendocrine modulation of the immune system during trauma and sepsis.

Sex-Specific Regulation of Gene Expression Networks by Surfactant Protein A (SP-A) Variants in Alveolar Macrophages in Response to Klebsiella pneumoniae

Surfactant protein A (SP-A) in addition to its surfactant-related functions interacts with alveolar macrophages (AM), the guardian cells of innate immunity in the lungs, and regulates many of its functions under basal condition and in response to various pressures, such as infection and oxidative stress. The human SP-A locus consists of two functional genes, SFTPA1 and SFTPA2, and one pseudogene. The functional genes encode human SP-A1 and SP-A2 proteins, respectively, and each has been identified with several genetic variants. SP-A variants differ in their ability to regulate lung function mechanics and survival in response to bacterial infection. Here, we investigated the effect of hSP-A variants on the AM gene expression profile in response to Klebsiella pneumoniae infection. We used four humanized transgenic (hTG) mice that each carried SP-A1 (6A², 6A⁴) or SP-A2 (1A⁰, 1A³), and KO. AM gene expression profiling was performed after 6 h post-infection. We found: (a) significant sex differences in the expression of AM genes; (b) in response to infection, 858 (KO), 196 (6A²), 494 (6A⁴), 276 (1A⁰), and 397 (1A³) genes were identified (P < 0.05) and some of these were differentially expressed with ≥2 fold, specific to either males or females; (c) significant SP-A1 and SP-A2 variant-specific differences in AM gene expression; (d) via Ingenuity Pathway Analysis (IPA), key pathways and molecules were identified that had direct interaction with TP53, TNF, and cell cycle signaling nodes; (e) of the three pathways (TNF, TP-53, and cell cycle signaling nodes) studied here, all variants except SP-A2 (1A³) female, showed significance for at least 2 of these pathways, and KO male showed significance for all three pathways; (f) validation of key molecules exhibited variant-specific significant differences in the expression between sexes and a similarity in gene expression profile was observed between KO and SP-A1. These results reveal for the first time a large number of biologically relevant functional pathways influenced in a sex-specific manner by SP-A variants in response to infection. These data may assist in studying molecular mechanisms of SP-A-mediated AM gene regulation and potentially identify novel therapeutic targets for K. pneumoniae infection.

When the balance is broken: X-linked gene dosage from two X chromosomes and female-biased autoimmunity

Women and men exhibit differences in innate and adaptive immunity, and women are more susceptible to numerous autoimmune disorders. Two or more X chromosomes increases the risk for some autoimmune diseases, and increased expression of some X-linked immune genes is frequently observed in female lymphocytes from autoimmune patients. Evidence from mouse models of autoimmunity also supports the idea that increased expression of X-linked genes is a feature of female-biased autoimmunity. Recent studies have begun to elucidate the correlation between abnormal X-chromosome inactivation (XCI), an essential mechanism female somatic cells use to equalize X-linked gene dosage between the sexes, and autoimmunity in lymphocytes. In this review, we highlight research describing overexpression of X-linked immunity-related genes and female-biased autoimmunity in both humans and mouse models, and make connections with our recent work elucidating lymphocyte-specific mechanisms of XCI maintenance that become altered in lupus patients.

Dehydroepiandrosterone: a potential therapeutic agent in the treatment and rehabilitation of the traumatically injured patient

Severe injuries are the major cause of death in those aged under 40, mainly due to road traffic collisions. Endocrine, metabolic and immune pathways respond to limit the tissue damage sustained and initiate wound healing, repair and regeneration mechanisms. However, depending on age and sex, the response to injury and patient prognosis differ significantly. Glucocorticoids are catabolic and immunosuppressive and are produced as part of the stress response to injury leading to an intra-adrenal shift in steroid biosynthesis at the expense of the anabolic and immune enhancing steroid hormone dehydroepiandrosterone (DHEA) and its sulphated metabolite dehydroepiandrosterone sulphate (DHEAS). The balance of these steroids after injury appears to influence outcomes in injured humans, with high cortisol: DHEAS ratio associated with increased morbidity and mortality. Animal models of trauma, sepsis, wound healing, neuroprotection and burns have all shown a reduction in pro-inflammatory cytokines, improved survival and increased resistance to pathological challenges with DHEA supplementation. Human supplementation studies, which have focused on post-menopausal females, older adults, or adrenal insufficiency have shown that restoring the cortisol: DHEAS ratio improves wound healing, mood, bone remodelling and psychological well-being. Currently, there are no DHEA or DHEAS supplementation studies in trauma patients, but we review here the evidence for this potential therapeutic agent in the treatment and rehabilitation of the severely injured patient.

The Pregnancy Pickle: Evolved Immune Compensation Due to Pregnancy Underlies Sex Differences in Human Diseases

We hypothesize that, ancestrally, sex-specific immune modulation evolved to facilitate survival of the pregnant person in the presence of an invasive placenta and an immunologically challenging pregnancy - an idea we term the 'pregnancy compensation hypothesis' (PCH). Further, we propose that sex differences in immune function are mediated, at least in part, by the evolution of gene content and dosage on the sex chromosomes, and are regulated by reproductive hormones. Finally, we propose that changes in reproductive ecology in industrialized environments exacerbate these evolved sex differences, resulting in the increasing risk of autoimmune disease observed in females, and a counteracting reduction in diseases such as cancer that can be combated by heightened immune surveillance. The PCH generates a series of expectations that can be tested empirically and that may help to identify the mechanisms underlying sex differences in modern human diseases.

Temporal progression of gene regulation of peripheral white blood cells explains gender dimorphism of critically ill patients after trauma

BACKGROUND

The immune response of the critically ill after severe trauma is sex-specific and may explain the different progression of the disease. This may be explained by a different gene regulatory program of their peripheral immune cells. We investigated the progression of the transcription profiles of peripheral immune cells of the patients to elucidate their distinct physiological response and clinical course.

METHODS

We compared transcription profiles of whole blood of male and female patients from a larger longitudinal study of critically ill patients after trauma. We developed a statistical analysis pipeline that synchronized the time lapse of the profiles based on the temporal severity score of each patient.

RESULTS

This enabled to categorize the temporal progression of the disease into two pre-acute, an acute and two post-acute phases. Comparing gene regulation of male and female patients at each phase, we identified distinctively regulated molecular processes mainly in the immune response, but also in the regulation of metabolism allowing to cluster these discriminative gene sets into sets of highly related cellular processes. Compared to male patients and healthy controls, female patients showed upregulation of gene sets of innate immunity in the early phase, upregulation of wound healing processes during the acute phase and upregulation of adaptive immunity in the late phase indicating early recovery. In turn, during the pre-acute and acute phase, male patients showed less suppression of gene sets coding for enzymes of energy metabolism and anabolism, most prominently the tricarboxylic acid cycle and β-oxidation, and cellular maintenance, such as cell cycle, DNA replication and damage response, and RNA metabolism.

CONCLUSIONS

A stronger innate immune response at the very early phase of the disease may support early clearance of the pathogen and its associated molecular patterns. Upregulation of wound healing processes may explain reduced multiple organ failure during the acute phase. Down regulated energy metabolism during the acute phase may make female patients less susceptible to oxidative stress, the upregulated adaptive immune system reflects an earlier recovery and rebuilding of the adaptive immune system that may protect them from secondary infections. Follow up studies need to be performed confirming these observations experimentally.

Pneumonia in severely injured patients with thoracic trauma: results of a retrospective observational multi-centre study

Background

While the incidence and aspects of pneumonia in ICU patients has been extensively discussed in the literature, studies on the occurrence of pneumonia in severely injured patients are rare. The aim of the present study is to elucidate factors associated with the occurrence of pneumonia in severely injured patients with thoracic trauma.

Setting

Level-I University Trauma Centres associated with the TraumaRegister DGU®.

Methods

A total of 1162 severely injured adult patients with thoracic trauma documented in the TraumaRegister DGU® (TR-DGU) were included in this study. Demographic data, injury severity, duration of mechanical ventilation (MV), duration of ICU stay, occurrence of pneumonia, bronchoalveolar lavage, aspiration, pathogen details, and incidences of mortality were evaluated. Statistical evaluation was performed using SPSS (Version 25.0, SPSS, Inc.) software.

Results

The overall incidence of pneumonia was 27.5%. Compared to patients without pneumonia, patients with pneumonia had sustained more severe injuries (mean ISS: 32.6 vs. 25.4), were older (mean age: 51.3 vs. 47.5) and spent longer periods under MV (mean: 368.9 h vs. 114.9 h). Age, sex (male), aspiration, and duration of MV were all independent predictors for pneumonia occurrence in a multivariate analysis. The cut-off point for duration of MV that best discriminated between patients who would and would not develop pneumonia during their hospital stay was 102 h. The extent of thoracic trauma (AIS_thorax), ISS, and presence of pulmonary comorbidities did not show significant associations to pneumonia incidence in our multivariate analysis. No significant difference in mortality between patients with and without pneumonia was observed.

Conclusions

Likelihood of pneumonia increases with age, aspiration, and duration of MV. These parameters were not found to be associated with differences in outcomes between patients with and without pneumonia. Future studies should focus on independent parameters to more clearly identify severely injured subgroups with a high risk of developing pneumonia.

Level of evidence

Level II - Retrospective medical record review.

Hormone Therapy in Trauma Patients

Low-dose hydrocortisone reduces the dose of vasopressors and hospital length of stay; it may also decrease the rate of hospital-acquired pneumonia and time on ventilator. No major side effect was reported, but glycemia and natremia should be monitored. Progesterone did not enhance outcome of trauma patients. A meta-analysis suggested that oxandrolone was associated with shorter length of stay and reduced weight loss. Erythropoietin did not enhance neurologic outcome of traumatic brain-injured patients; such treatment, however, could reduce the mortality in subgroups of patients. This review focuses mainly on glucocorticoids, which are the most extensively investigated treatments in hormone therapy.

Haptoglobin improves acute phase response and endotoxin tolerance in response to bacterial LPS

Sepsis is characterized by delayed acute phase response and lowered immune tolerance in patients. Acute phase serum proteins, like Haptoglobin (Hp), have been associated with increased mortality in bacteria mediated acute lung inflammation and sepsis in neonates. However, it's direct role in modulating the immune response by regulating pro-inflammatory mediators leading to immune tolerant state and if gender affects its expression levels during bacterial infection, especially in blood has not been fully explored. To understand its specific role in endotoxin-mediated immune response, we investigated the correlation between the rise in Hp levels on bacterial infection and its influence on the expression of pro-inflammatory mediators in male and female Whole blood (WHB) and PBMCs. Here, we observed pathogen-specific and gender-specific expression of Hp. Gonadal steroid hormones differentially influenced the Hp expression in LPS-induced WHB, where the addition of Estrogen increased Hp expression, with suppression of TNFα, in both genders. Further on evaluating, the influence of Hp on TNFα expression in endotoxin tolerance (ET), we show that increased Hp levels directly reduced TNFα expression in ET models. Interestingly, blockade of secreted Hp significantly reversed the (ET) state, confirmed by a significant rise in TNFα expression in both ex vivo and in vitro ET models, indicating a possible feedback inhibition by Hp on inflammatory mediators like TNFα. We also investigated the role of PKCδ in the regulation of LPS induced secretion of acute phase proteins (Hp) in serum, where inhibition of PKCδ, reduced secretion of anti-microbial proteins in response to LPS shown by restored bacterial growth. These findings clearly highlight the crucial role of Hp in maintaining immune tolerance via suppressing the pro-inflammatory mediators and also in preventing bacterial proliferation in blood during infection.

Gender Disparities in Trauma Care: How Sex Determines Treatment, Behavior, and Outcome

Trauma data bank and other research reveal sex disparities in trauma care. Risk-taking behaviors leading to traumatic injury have been associated with sex, menstrual cycle timing, and cortisol levels. Trauma patient treatment stratified by sex reveals differences in access to services at trauma centers as well as specific treatments, such as venous thromboembolism prophylaxis and massive transfusion component ratios. Trauma patient outcomes, such as in-hospital mortality, multiple organ failure, pneumonia, and sepsis are associated with sex disparities in the general trauma patient. Outcome after general trauma and specifically traumatic brain injury show mixed results with respect to sex disparity.

Gender differences in trauma, shock and sepsis

Despite efforts in prevention and intensive care, trauma and subsequent sepsis are still associated with a high mortality rate. Traumatic injury remains the main cause of death in people younger than 45 years and is thus a source of immense social and economic burden. In recent years, the knowledge concerning gender medicine has continuously increased. A number of studies have reported gender dimorphism in terms of response to trauma, shock and sepsis. However, the advantageous outcome following trauma-hemorrhage in females is not due only to sex. Rather, it is due to the prevailing hormonal milieu of the victim. In this respect, various experimental and clinical studies have demonstrated beneficial effects of estrogen for the central nervous system, the cardiopulmonary system, the liver, the kidneys, the immune system, and for the overall survival of the host. Nonetheless, there remains a gap between the bench and the bedside. This is most likely because clinical studies have not accounted for the estrus cycle. This review attempts to provide an overview of the current level of knowledge and highlights the most important organ systems responding to trauma, shock and sepsis. There continues to be a need for clinical studies on the prevailing hormonal milieu following trauma, shock and sepsis.

Survival of Surfactant Protein-A1 and SP-A2 Transgenic Mice After Klebsiella pneumoniae Infection, Exhibits Sex-, Gene-, and Variant Specific Differences; Treatment With Surfactant Protein Improves Survival

Surfactant protein A (SP-A) is involved in lung innate host defense and surfactant-related functions. The human SFTPA1 and SFTPA2 genes encode SP-A1 and SP-2 proteins, and each gene has been identified with numerous genetic variants. SP-A1 and SP-A2 differentially enhance bacterial phagocytosis. Sex differences have been observed in pulmonary disease and in survival of wild type and SP-A knockout (KO) mice. The impact of human SP-A variants on survival after infection is unknown. In this study, we determined whether SP-A variants differentially affect survival of male and female mice infected with Klebsiella pneumoniae. Transgenic (TG) mice, where each carries a different human (h) SP-A1 (6A², 6A⁴), SP-A2 (1A⁰, 1A³) variant or both variants SP-A1/SP-A2 (6A²/1A⁰, co-ex), and SP-A- KO, were utilized. The hTG and KO mice were infected intratracheally with K. pneumoniae bacteria, and groups of KO mice were treated with SP-A1 or SP-A2 either prior to and/or at the time of infection and survival for both experimental groups was monitored over 14 days. The binding of purified SP-A1 and SP-A2 proteins to phagocytic and non-phagocytic cells and expression of cell surface proteins in alveolar macrophages (AM) from SP-A1 and SP-A2 mice was examined. We observed gene-, variant-, and sex-specific (except for co-ex) differences with females showing better survival: (a) Gene-specific differences: co-ex = SP-A2 > SP-A1 > KO (both sexes); (b) Variant-specific survival co-ex (6A²/1A⁰) = 1A⁰ > 1A³ = 6A² > 6A⁴ (both sexes); (c) KO mice treated with SPs (SP-A1 or SP-A2) proteins exhibit significantly (p < 0.05) better survival; (d) SP-A1 and SP-A2 differentially bind to phagocytic, but not to non-phagocytic cells, and AM from SP-A1 and SP-A2 hTG mice exhibit differential expression of cell surface proteins. Our results indicate that sex and SP-A genetics differentially affect survival after infection and that exogenous SP-A1/SP-A2 treatment significantly improves survival. We postulate that the differential SP-A1/SP-A2 binding to the phagocytic cells and the differential expression of cell surface proteins that bind SP-A by AM from SP-A1 and SP-A2 mice play a role in this process. These findings provide insight into the importance of sex and innate immunity genetics in survival following infection.

Early clinical predictors of pneumonia in critically ill spinal cord injured individuals: a retrospective cohort study

STUDY DESIGN

Retrospective cohort.

OBJECTIVES

Pneumonia is the dominant complication following traumatic spinal cord injury (SCI) and profoundly impacts morbidity by prolonging length of stay and worsening neurological outcome. The aims of this study were to determine the key predictors of clinically important pneumonia (CIP); and to examine the impact of CIP on resource utilisation in critically ill acute traumatic SCI individuals between 2010 and 2015.

SETTING

Alfred and Austin Hospitals (Melbourne, Australia).

METHODS

Data were extracted from the medical records of 93 cases of acute traumatic SCI resulting in ISNCSCI C3-L1 level of injury requiring admission to the intensive care unit and aged between 15 and 70 years. Patients with life-threatening injuries, not requiring spinal surgery, palliated within 7 days of injury, diagnosis of traumatic central cord syndrome or with poor general health, were excluded.

RESULTS

A total of 33 episodes of CIP were observed. Median time to CIP diagnosis was 65 h (IQR: 42-93) and median time to spinal surgery was 22 h (IQR: 12-32). Four key predictors were identified; male gender (OR: 18.3, CI: 1.9-174.9, p = 0.001), motor complete injury (OR: 10.1, CI: 1.1-92.1, p = 0.011), presence of chest trauma (OR: 4.5, CI: 1.4-14.4, p = 0.007) and delayed intubation (HR: 6.8, CI: 1.6-28.6, p = 0.009).

CONCLUSIONS

This study identifies four key predictors involved in elevated pneumonia risk; male gender, motor complete injury, presence of chest trauma and delayed intubation, enabling the future synthesis of a pneumonia prediction tool for use in the acute postinjury period.

Age and Number of Surgeries Increase Risk for Complications in Polytrauma Patients with Operative Maxillofacial Fractures

BACKGROUND

Poly-trauma patients often sustain complex head/neck injuries requiring prolonged hospitalizations and multiple operations. Few studies have evaluated the associated injury patterns and risk factors for poor clinical outcomes.

METHODS

Consecutive poly-trauma patients with operative maxillofacial fractures treated at a level 1 trauma medical center between 1995 and 2013 were evaluated. Concomitant head/neck injuries to identify potential injury patterns were numerated. Lastly, a multivariate analysis was performed to determine independent risk factors for complications during the acute hospitalization period.

RESULTS

Totally, 232 poly-trauma patients presented with operative maxillofacial fractures, while 38.8% of patients had a secondary maxillofacial fracture, 16.4% had intracranial hemorrhage, 23.7% had skull fractures, and 12.1% had spinal fractures. The rate of complication during admission was 28.3%. Multivariate analysis revealed advanced patient age and increased number of operations to predict the rate of complication. Patients requiring more than one operation had a 1.8-fold increase in complication rate (p<0.01) and older patients had a 4.5% increase in complication rate (p<0.05) for every year of increased age.

CONCLUSION

Poly-trauma patients have a high incidence of secondary maxillofacial fractures, concomitant head/neck injury, and inpatient complication rate. Knowledge of associated injury patterns can help increased awareness and can guide physician decision-making to avoid missed/delayed injuries.

Aesthetic Surgical Procedures in Men: Major Complications and Associated Risk Factors

BACKGROUND

The number of men undergoing cosmetic surgery is increasing in North America.

OBJECTIVES

To determine the incidence and risk factors of major complications in males undergoing cosmetic surgery, compare the complication profiles between men and women, and identify specific procedures that are associated with higher risk of complications in males.

METHODS

A prospective cohort of patients undergoing cosmetic surgery between 2008 and 2013 was identified from the CosmetAssure database. Gender specific procedures were excluded. Primary outcome was occurrence of a major complication in males requiring emergency room visit, hospital admission, or reoperation within 30 days of the index operation. Univariate and multivariate analysis evaluated potential risk factors for major complications including age, body mass index (BMI), smoking, diabetes, type of surgical facility, type of procedure, and combined procedures.

RESULTS

Of the 129,007 patients, 54,927 underwent gender nonspecific procedures, of which 5801 (10.6%) were males. Women showed a higher mean age (46.4 ± 14.1 vs 45.2 ± 16.7 years, P < 0.01). Men had a higher BMI (27.2 ± 4.7 vs 25.7 ± 4.9 kg/m2, P < 0.01), and were more likely to be smokers (7.1% vs 5.7%, P < 0.01) when compared to women. Men demonstrated similar overall major complication rates compared to women (2.1% vs 2.1%, P = 0.97). When specific complications were analyzed further, men had higher hematoma rates, but lower incidence of surgical site infection. Additionally, major complications after abdominoplasty, facelift surgery, and buttock augmentation were noted to preferentially affect males. On multivariate analysis, independent predictors of major complications in males included BMI (RR 1.05), hospital or ambulatory surgery center procedures (RR 3.47), and combined procedures (RR 2.56).

CONCLUSIONS

Aesthetic surgery in men is safe with low major complication rates. Modifiable predictors of complications included BMI and combined procedures.

LEVEL OF EVIDENCE 2

Differential effects of innate immune variants of surfactant protein-A1 (SFTPA1) and SP-A2 (SFTPA2) in airway function after Klebsiella pneumoniae infection and sex differences

Background

Surfactant Protein-A (SP-A) is a major protein component of surfactant and plays a role in surfactant-related functions and innate immunity. Human SP-A consists of two functional genes, SFTPA1 and SFTPA2, encoding SP-A1 and SP-A2 proteins, respectively and each is identified with numerous genetic variants. These differentially enhance bacterial phagocytosis, with SP-A2 variants being more effective than SP-A1.

Methods

Lung functions of humanized transgenic (hTG) mice that carry different SP-A1 and SP-A2 variants or both variants SP-A1/SP-A2 (6A²/1A⁰, co-ex), as well as SP-A knockout (KO), were studied. The animals were connected to a flexiVent system to obtain forced oscillation technique (FOT) measurements and the data were analyzed using various models. Lung function was assessed after infection (baseline) and following inhaled methacholine concentrations (0–50 mg/mL).

Results

Here, we investigated the role of SP-A variants on airway function after Klebsiella pneumoniae (Kp) infection (baseline) and following inhaled methacholine. We found that: 1) in the absence of methacholine no significant differences were observed between SP-A1 and SP-A2 variants and/or SP-A knockout (KO) except for sex differences in most of the parameters studied. 2) In response to methacholine, i) sex differences were observed that were reverse of those observed in the absence of methacholine; ii) SP-A2 (1A³) gene variant in males exhibited increased total and central airway resistance (Rrs and Rn) versus all other variants; iii) In females, SP-A2 (1A³) and SP-A1 (6A²) variants had similar increases in total and central airway resistance (Rrs and Rn) versus all other variants; iv) Allele-specific differences were observed, a) with SP-A2 (1A³) exhibiting significantly higher lung functions versus SP-A2 (1A⁰) in both sexes, except for Crs, and b) SP-A1 (6A², 6A⁴) had more diverse changes in lung function in both sexes.

Conclusion

We conclude that, in response to infection and methacholine, SP-A variants differentially affect lung function and exhibit sex-specific differences consistent with previously reported findings of functional differences of SP-A variants. Thus, the observed changes in respiratory function mechanics provide insight into the role and importance of genetic variation of innate immune molecules, such as SP-A, on mechanical consequences of lung function after infection and inhaled substances.

The Role and Use of Estrogens Following Trauma

Several lines of evidence indicate that female sex is a protective factor in trauma and hemorrhage. In both clinical and experimental studies, proestrus females have been shown to have better chances of survival and reduced rates of posttraumatic sepsis. Estrogen receptors are expressed in a variety of tissues and exert genomic, as well as nongenomic effects. By improving cardiac, pulmonary, hepatic, and immune function, estrogens have been shown to prolong survival in animal models of hemorrhagic shock. Despite encouraging results from experimental studies, retrospective clinical studies have not clearly pointed to advantages of estrogens following trauma-hemorrhage, which may be due to insufficient study design. Therefore, this review aims to give an overview on the current evidence and emphasizes on the importance of further clinical investigation on estrogens following trauma.

Differential Susceptibility to Infectious Respiratory Diseases between Males and Females Linked to Sex-Specific Innate Immune Inflammatory Response

It is widely acknowledged that males and females exhibit contrasting degrees of susceptibility to infectious and non-infectious inflammatory diseases. This is particularly observed in respiratory diseases where human males are more likely to be affected by infection-induced acute inflammations compared to females. The type and magnitude of the innate immune inflammatory response play a cardinal role in this sex bias. Animal models mimicking human respiratory diseases have been used to address the biological factors that could explain the distinct outcomes. In this review, we focus on our current knowledge about experimental studies investigating sex-specific differences in infection-induced respiratory diseases and we provide an update on the most important innate immune mechanisms that could explain sex bias of the inflammatory response. We also discuss whether conclusions drawn from animal studies could be relevant to human.

Sex Differences in Trajectories of Risk After Rehospitalization for Heart Failure, Acute Myocardial Infarction, or Pneumonia

BACKGROUND

Women have an increased risk of rehospitalization in the immediate postdischarge period; however, few studies have determined how readmission risk dynamically changes on a day-to-day basis over the full year after hospitalization by sex and how these differences compare with the risk for mortality.

METHODS AND RESULTS

We identified >3 000 000 hospitalizations of patients with a principal discharge diagnosis of heart failure, acute myocardial infarction, or pneumonia and estimated sex differences in the daily risk of rehospitalization/death 1 year after discharge from a population of Medicare fee-for-service beneficiaries aged 65 years and older. We calculated the (1) time required for adjusted rehospitalization/mortality risks to decline 50% from maximum values after discharge, (2) time required for the adjusted readmission risk to approach plateau periods of minimal day-to-day change, and (3) extent to which adjusted risks are greater among recently hospitalized patients versus Medicare patients. We identified 1 392 289, 530 771, and 1 125 231 hospitalizations for heart failure, acute myocardial infarction, and pneumonia, respectively. The adjusted daily risk of rehospitalization varied by admitting condition (hazard rate ratio for women versus men, 1.10 for acute myocardial infarction; hazard rate ratio, 1.04 for heart failure; and hazard rate ratio, 0.98 for pneumonia). However, for all conditions, the adjusted daily risk of death was higher among men versus women (hazard rate ratio women versus with men, <1). For both sexes, there was a similar timing of peak daily risk, half daily risk, and reaching plateau.

CONCLUSIONS

Although the association of sex with daily risk of rehospitalization varies across conditions, women are at highest risk after discharge for acute myocardial infarction. Future studies should focus on understanding the determinants of sex differences in rehospitalization risk among conditions.

The influence of sex steroid hormones on the response to trauma and burn injury

Trauma and related sequelae result in disturbance of homeostatic mechanisms frequently leading to cellular dysfunction and ultimately organ and system failure. Regardless of the type and severity of injury, gender dimorphism in outcomes following trauma have been reported, with females having lower mortality than males, suggesting that sex steroid hormones (SSH) play an important role in the response of body systems to trauma. In addition, several clinical and experimental studies have demonstrated the effects of SSH on the clinical course and outcomes following injury. Animal studies have reported the ability of SSH to modulate immune, inflammatory, metabolic and organ responses following traumatic injury. This indicates that homeostatic mechanisms, via direct and indirect pathways, can be maintained by SSH at local and systemic levels and hence result in more favourable prognosis. Here, we discuss the role and mechanisms by which SSH modulates the response of the body to injury by maintaining various processes and organ functions. Such properties of sex hormones represent potential novel therapeutic strategies and further our understanding of current therapies used following injury such as oxandrolone in burn-injured patients.

Smoking, Gender, and Overweight Are Important Influencing Factors on Monocytic HLA-DR before and after Major Cancer Surgery

Background

Monocytic human leukocyte antigen D related (mHLA-DR) is essential for antigen-presentation. Downregulation of mHLA-DR emerged as a general biomarker of impaired immunity seen in patients with sepsis and pneumonia and after major surgery. Influencing factors of mHLA-DR such as age, overweight, diabetes, smoking, and gender remain unclear.

Methods

We analyzed 20 patients after esophageal or pancreatic resection of a prospective, randomized, placebo-controlled, double-blind trial (placebo group). mHLA-DR was determined from day of surgery (od) until postoperative day (pod) 5. Statistical analyses were performed using multivariate generalized estimating equation analyses (GEE), nonparametric multivariate analysis of longitudinal data, and univariate post hoc nonparametric Mann–Whitney tests.

Results

In GEE, smoking and gender were confirmed as significant influencing factors over time. Univariate analyses of mHLA-DR between smokers and nonsmokers showed lower preoperative levels (p = 0.010) and a trend towards lower levels on pod5 (p = 0.056) in smokers. Lower mHLA-DR was seen in men on pod3 (p = 0.038) and on pod5 (p = 0.026). Overweight patients (BMI > 25 kg/m²) had lower levels of mHLA-DR on pod3 (p = 0.039) and pod4 (p = 0.047).

Conclusion

Smoking is an important influencing factor on pre- and postoperative immune function while postoperative immune function was influenced by gender and overweight. Clinical trial registered with ISRCTN27114642.

Pneumonia in Trauma Patients

Purpose of Review

This article reviews the new definitions of pneumonia, discusses risk factors for pneumonia among trauma patients, presents the latest evidence for prevention strategies, discusses the best ways to make the diagnosis, and reviews the microbiology and treatment for trauma patients with pneumonia.

Recent Findings

Pneumonia can be prevented by decreasing the duration of mechanical ventilation using daily paired spontaneous awakening and breathing trials, but not with early tracheostomy placement. Other useful prevention strategies include semirecumbent positioning and oral care. Mini-BAL is a sensitive and specific means of securing the diagnosis of pneumonia that does not require a physician to be present and is therefore especially useful in busy trauma centers.

Summary

Pneumonia is a frequent complication among trauma patients. Risk factors are largely unmodifiable. However, trauma centers can institute routine daily paired spontaneous awakening and breathing trials to decrease the duration of ventilation and incidence of pneumonia. Future research is needed to further characterize the microbiology of pneumonia among trauma patients.

Necroptosis as a potential therapeutic target in multiple organ dysfunction syndrome

Purpose

To investigate how necroptosisis, i.e. programmed necrosis, is involved in MODS, and to examine whether Nec-1, a specific necroptosis inhibitor, ameliorates multiorgan injury in MODS.

Experimental Design

A model of MODS was established in six-week old SD rats using fracture trauma followed by hemorrhage. Control animals received sham surgery. Cell death form and necrosome formation were measured by fluorescence-activated cell sorting and western blotting. MODS rats were randomly assigned to receive Nec-1 or saline with pretreatment and once daily. The first end-point was 72 hours survival. Organ injury and dysfunction, inflammatory cytokine levels, and necroptotic execution protein expression were also recorded.

Results

Organ injury and dysfunction were significantly more severe in the MODS group than the sham group (all p<0.01). Furthermore, MODS-induced liver, lung and kidney tissue injury was characterized by necroptosis rather than apoptosis, and accompanied by necrosome formation. Compared to MODS group, Nec-1 administration significantly improved 72 hours survival (p<0.01). Nec-1 administration significantly reduced necroptosis-induced liver, lung and kidney injury and dysfunction, inhibited inflammatory cytokines production, inhibited release of necroptotic execution proteins such as high-mobility group box 1 and mixed-lineage kinase domain-like protein pseudokinase in MODS rats (all p<0.01).

Conclusions

These results suggest that necroptosis is involved the pathology of MODS. Further, a necroptotic inhibitor Nec-1 may be considered as an adjunct treatment for MODS.