The impact of body mass index on the development of systemic inflammatory response syndrome and sepsis in patients with polytrauma

Correlation between body mass index and gender-specific 28-day mortality in patients with sepsis: a retrospective cohort study

Objective

To investigate the potential correlation between body mass index (BMI) and the 28-day mortality rate among sepsis patients and the gender difference in this association.

Design

The current research was a retrospective cohort study.

Participants

A total of 14,883 male and female cohorts of sepsis patients were included in the Medical Information Mart for Intensive Care IV (MIMIC-IV V2.2) database. Patients in each gender cohort were further classified as underweight, normal weight, overweight, or obese according to BMI and the World Health Organization (WHO) BMI categories.

Outcomes

The 28-day mortality from the date of ICU hospitalization was the primary outcome measure.

Results

The BMI and 28-day mortality exhibited an L-shaped relationship (p for nonlinearity <0.001) with significant gender-specific differences. Subgroup analysis revealed different association patterns between the male and female cohorts. Specifically, BMI and mortality exhibited a U-shaped curve relationship among the males (p for nonlinearity <0.001) and an L-shaped relationship among the females (p for nonlinearity = 0.045).

Conclusion

This study proposes a link between extreme BMI and 28-day mortality in patients with sepsis. Underweight patients have an increased risk of mortality; however, this risk decreases in overweight and obese patients. Upon stratifying by sex, a U-shaped pattern was observed, indicating an association between BMI and 28-day mortality in males, while an L-shaped pattern emerged in females.

The Utility of C-Reactive Protein, Procalcitonin, and Leukocyte Values in Predicting the Prognosis of Patients with Pneumosepsis and Septic Shock

Background and Objectives: The predictive value of changes in C-reactive protein (CRP), procalcitonin, and leukocyte levels, which are commonly used in the diagnosis of infection in sepsis and septic shock, remains a topic of debate. The aim of this study was to evaluate the effectiveness of changes in CRP, procalcitonin, and leukocyte counts on the prognosis of 230 patients admitted to the intensive care unit (ICU) with the diagnosis of sepsis and pneumonia-related septic shock between 1 April 2022 and 31 December 2023, and to investigate whether any of these markers have a superior predictive value over the others in forecasting prognosis. Materials and Methods: This single-center, retrospective, cross-sectional observational study included patients who developed sepsis and septic shock due to community-acquired pneumonia and were admitted to the ICU. Demographic data, 1-month and 90-day mortality rates, length of stay in the ICU, discharge to the ward or an outside facility, need for dialysis after sepsis, need for invasive or noninvasive mechanical ventilation during the ICU stay and the duration of this support, whether patients admitted with sepsis or septic shock required inotropic agent support during their stay in the ICU and whether they received monotherapy or combination therapy with antibiotics during their admission to the ICU, the Comorbidity Index score (CCIS), CURB-65 score (confusion, uremia, respiratory rate, BP, age ≥ 65), and Acute Physiology and Chronic Health Evaluation II (APACHE-II) score were analyzed. Additionally, CRP, procalcitonin, and leukocyte levels were recorded, and univariate and multivariate logistic regression analyses were performed to evaluate their effects on 1- and 3-month mortality outcomes. In all statistical analyses, a p-value of <0.05 was accepted as a significant level. Results: According to multivariate logistic regression analysis, low BMI, male gender, and high CCIS, CURB-65, and APACHE-II scores were found to be significantly associated with both 1-month and 3-month mortality (p < 0.05). Although there was no significant relationship between the first-day levels of leukocytes, CRP, and PCT and mortality, their levels on the third day were observed to be at their highest in both the 1-month and 3-month mortality cases (p < 0.05). Additionally, a concurrent increase in any two or all three of CRP, PCT, and leukocyte values was found to be higher in patients with 3-month mortality compared with those who survived (p = 0.004). Conclusions: In patients with pneumoseptic or pneumonia-related septic shock, the persistent elevation and concurrent increase in PCT, CRP, and leukocyte values, along with male gender, advanced age, low BMI, and high CCIS, CURB-65, and APACHE-II scores, were found to be significantly associated with 3-month mortality.

Influence of higher body mass index on postoperative nausea and vomiting in patients following thoracic surgery for lung cancer: a propensity score-matched cohort study

This study aimed to quantify the association between body mass index (BMI) and postoperative nausea and vomiting (PONV) within the initial 48 h following thoracic surgery for lung cancer. We then explored whether changes in serum inflammatory factor concentrations were related to BMI during the early postoperative period. We conducted a propensity score-matched (PSM), retrospective cohort study at a specialized tertiary medical center. A total of 194 patients aged 18-80 years who underwent thoracic surgery for lung cancer at Shanghai Pulmonary Hospital between January and June 2021 were enrolled. The primary outcome was the incidence of PONV during the first 48 h after surgery. Nausea, vomiting or retching at different time periods, severe pain, and concentrations of perioperative serum inflammatory factors including CRP, IL-6, IL-12, and IFN-γ were also assessed. Patients in the high BMI group (BMI ≥ 25 kg/m2) had a lower incidence of PONV than those in the normal BMI group (18.5-25 kg/m2) within the first 48 h after surgery (22 vs. 50%, p = 0.004). The incidence of nausea was lower at 0-12 h (14.5 vs. 37.1%, p = 0.004) and 12-24 h (8.1 vs. 22.6%, p = 0.025) in the high BMI group after surgery, and the incidence of vomiting was lower at 0-12 h (12.9 vs. 30.6%, p = 0.017) in higher BMI after surgery. We found no significant difference in the incidence of severe pain [severe static pain (p = 0.697) and severe dynamic pain (p = 0.158)]. Moreover, higher concentrations of IL-12 (2.24 ± 2.67 pg/ml vs. 1.48 ± 1.14 pg/ml, p = 0.048) and IFN-γ [1.55 (1.00) pg/ml vs. 1.30 (0.89) pg/ml, p = 0.041] were observed in patients with normal BMI on the first day after surgery. Given this finding, patients with a normal BMI should receive more attention for the prevention of PONV than those with a high BMI following thoracic surgery for lung cancer.Trial registration: http://www.chictr.org.cn and ChiCTR2100052380 (24/10/2021).

Independent predictors of systemic inflammatory response syndrome for intramedullary nailing of femoral shaft fractures: Analysis of national inpatient sample database

Background

The systemic inflammatory response syndrome (SIRS) is a clinical reaction that can occur due to a variety of stimuli. Reamed intramedullary femoral nailing is a common orthopedic surgery that has been shown to induce SIRS. To date, no nationwide analyses have been performed to evaluate the incidence, risk factors, and economic burdens of SIRS following intramedullary femoral nailing for femoral shaft fractures. The objective of this study is to investigate the independent predictors, incidence, post-operative, and economic burden of SIRS among patients treated with intramedullary nailing for femoral shaft fractures.

Methods

We utilized the 2016-2019 National Inpatient Sample (NIS) to identify patients who underwent intramedullary femoral nailing and were diagnosed with non-infectious SIRS (NI-SIRS) based on ICD-10-CM coding. Identified patients who underwent intramedullary femoral nailing were dichotomized into SIRS and Non-SIRS groups to assess independent predictors of SIRS development, and to compare post-operative complications and costs.

Results

A total of 65,240 patients with femur shaft fractures underwent IMFN, of which 665 (1.0 %) developed NI-SIRS. Patients with NI-SIRS had a higher incidence of laparotomy (OR = 13.97, p < 0.001), initial treatment with external fixation (OR = 1.845, p < 0.001), and late application of external fixation (OR = 4.884, p = 0.005). Routine discharge (OR = 0.491, p < 0.001) was less likely in patients with NI-SIRS. Length of stay (12.38 days vs 7.16 days, p < 0.001) and total charges ($278, 590 vs $145,118, p < 0.001) were both increased in patients with NI-SIRS.

Conclusion

NI-SIRS is associated with increasing injury severity and post-operative complications. Those that developed NI-SIRS experienced higher healthcare resource utilization. Risk factors associated with development of NI-SIRS warrant further investigation.

The association between obesity with treatment duration, ICU length of stay and the risk of death in critically ill patients with COVID-19

BACKGROUND

Despite the confirmed association between higher BMI with increased risk of the acute respiratory distress syndrome (ARDS), the association between obesity with mortality in critically ill patients with coronavirus disease 2019 (COVID-19) is not clear. The present study aimed to investigate the association between obesity with treatment duration, ICU length of stay, and the risk of death in critically ill patients with COVID-19.

METHODS

This case-control study was performed on 223 patients with COVID-19 including 148 surviving patients as the control group and 75 eventually dead patients as the case group in Rasht, Iran. Data on demographic factors, comorbidities, anthropometric measurements, the length of hospitalization and the mortality were obtained from patients' medical records.

RESULTS

The mortality rate was significantly associated with weight (OR = 1.04, 95% CI: 1.002-1.083, p = .04), but not with BMI after adjustments for age, gender, length of stay in ICU, chronic diseases and smoking. The results did not change after further adjustments for biochemical and pathological factors.

CONCLUSIONS

Weight was positively associated with mortality after controlling for confounding variables. Further studies should consider the patient's body composition such as fat mass to establish the relationship between obesity and COVID-19 outcomes.

Exploring the Causality Between Body Mass Index and Sepsis: A Two-Sample Mendelian Randomization Study

Objective: Observational epidemiological studies have shown a link between obesity and sepsis, but any causal relationship is not clear. Our study aimed to explore the correlation and causal relationship between body mass index and sepsis by a two-sample Mendelian randomization (MR). Methods: In large sample genome-wide association studies, single-nucleotide polymorphisms related to body mass index were screened as instrumental variables. Three MR methods, MR-Egger regression, weighted median estimator, and inverse variance-weighted, were used to evaluate the causal relationship between body mass index and sepsis. Odds ratio (OR) and 95% confidence interval (CI) were used as the evaluation index of causality, and sensitivity analyses were conducted to assess pleiotropy and instrument validity. Results: By two-sample MR, the inverse variance weighting method results suggested that increased body mass index was associated with an increased risk of sepsis (odds ratio 1.32; 95% CI 1.21-1.44; p = 1.37 × 10^-9) and streptococcal septicemia (OR 1.46; 95% CI 1.11-1.91; p = 0.007), but there was no causal relationship with puerperal sepsis (OR, 1.06; 95% CI, 0.87-1.28; p = 0.577). Sensitivity analysis was consistent with the results, and there was no heterogeneity and level of pleiotropy. Conclusion: Our study supports a causal relationship between body mass index and sepsis. Proper control of body mass index may prevent sepsis.

The Effect of Fat Distribution on the Inflammatory Response of Multiple Trauma Patients-A Retrospective Study

Objectives In recent years; increasing evidence pointed out the clinical importance of adipose tissue (AT) distribution in various patient populations. In particular, visceral adipose tissue (VAT), when compared to subcutaneous adipose tissue (SAT), was found to play a pivotal role in the development of inflammatory reaction. The aim of the present study was to examine whether body fat distribution has an impact on the development of systemic inflammatory response syndrome (SIRS) in patients with polytrauma. Methods In our retrospective study; we filtered our institution records of the German Trauma Registry (Trauma Register DGU) from November 2018 to April 2021 and included 132 adult polytrauma patients with injury severity score (ISS) >16. Subsequently; we measured the visceral and subcutaneous adipose tissue area based on whole-body CT scan and calculated the ratio of VAT to SAT (VSr). Thereafter, the patient population was evenly divided into three groups; respectively VSr value less than 0.4 for the first group (low ratio), 0.4–0.84 for the second group (intermediate ratio), and greater than 0.84 for the third group (high ratio). Considering the other influencing factors; the groups were further divided into subgroups in the respective analysis according to gender (male/female), BMI (<25 or ≥25), and ISS (<26 or ≥26). Result VSr was an independent factor from body mass index (BMI) (r² = 0.003; p = 0.553). VSr in male patients was significantly higher (p < 0.001). Patients with low VSr had higher ISS scores (p = 0.028). Polytrauma patients with higher VSr tended to have lower SIRS scores and significant differences of SIRS score were found on multiple days during the whole hospitalization period. In the low VAT/SAT group, male patients, and patients with BMI greater than 25, both exhibited higher SIRS scores during hospital stay (day 16: p = 0.01; day 22: p = 0.048 and p = 0.011; respectively). During hospitalization, patients with higher ISS score (≥26) in the low VSr group was found to have higher SIRS score (day 16; p = 0.007). Over the hospital stay; serum markers of CRP; CK; and leukocyte in patients with low VSr were higher than those in patients in the intermediate and high VSr groups; with significant difference discovered on multiple days (day 16: 0.014; day 22: p = 0.048). Conclusion Lower VSr is associated with increased inflammatory response and worse clinical outcome in patients with polytrauma. Furthermore; VSr is an independent factor providing additional information to BMI.

Low body mass index is associated with increased mortality in patients with pelvic and acetabular fractures

AIMS

Fractures of the pelvis and acetabulum are often the consequence of high energy trauma in young individuals or fragility fractures in osteoporotic bone. They can be life-threatening or life changing injuries. No published data exists comparing body mass index (BMI) and mortality for this patient group. The aim of this study was to identify if low BMI (<18.5) was a predictor of morbidity and mortality for patients with these injuries.

PATIENTS AND METHODS

Of the 1033 patients with pelvic or acetabular fractures referred to a single level 1 major trauma centre (MTC) over a 4.5-year period (August 2015 - January 2020); we retrospectively analysed data for all admitted patients. Data was collected on demographics, injury pattern, operative intervention and complications. Comparison was made between patients that were underweight (BMI<18.5) and patients that were not. Both in-hospital and post discharge complications were recorded including pulmonary embolus (PE), deep venous thrombosis (DVT), ileus, infection, loss of reduction and mortality at 6 months.

RESULTS

569 patients admitted to the MTC with a pelvic or acetabular fracture were included in our analysis. Underweight patients had a statistically significant increase in mortality both in-hospital (p = 0.019) and at 6 months post injury (p = 0.039) when compared to other BMI groups. No statistical significance was found between these BMI groups comparing morbidity: DVT (p = 0.712), PE (p = 0.736) nor ileus (p = 0.149). Covariate analysis showed that a low BMI was associated with triple the in-hospital mortality after correction for age and energy of injury (adjusted OR 3.028, 95% CI 1.059-8.659).

CONCLUSION

This is the first published study that demonstrates a statistically significant increase in mortality in patients with pelvic or acetabular fractures who are underweight. Surgeons should carefully consider appropriate peri-operative optimisation for these patients. Further investigation into the effects of low BMI and response to trauma is required.

Interleukin-6 Is an Early Plasma Marker of Severe Postoperative Complications in Thoracic Surgery: Exploratory Results From a Substudy of a Randomized Controlled Multicenter Trial

BACKGROUND

Postoperative complications in surgery are a significant burden, not only for the patients but also economically. While several predicting factors have already been identified, it is still not well known if increased levels of inflammatory markers in the immediate perioperative phase correlate with a higher incidence of postoperative complications. This study aimed to evaluate which patient characteristics and intraoperative parameters correlate with increased plasma values of monocyte chemoattractant protein 1 (MCP-1) and interleukin 6 (IL-6) of thoracic surgery patients. A second goal was to explore whether MCP-1 and IL-6 are associated with the incidence of postoperative complications. We hypothesized that there is a positive association between inflammatory markers and the occurrence of complications within 6 months after surgery.

METHODS

This is a substudy of a recent randomized controlled trial, which defined the effect of desflurane versus propofol anesthesia on morbidity and mortality in patients undergoing thoracic surgery. MCP-1 and IL-6 were determined in plasma obtained before and 30 minutes after 1-lung ventilation, 6 hours after surgery, and on postoperative days 1 and 2. Complications were recorded for 6 months. Mixed linear models were used to examine factors associated with MCP-1 and IL-6 levels. Logistic regression models and receiver operating characteristic curves were used to determine the association between MCP-1 and IL-6 and postoperative complications.

RESULTS

In the original study, 460 patients were included, MCP-1 and IL-6 levels were determined in 428 patients. MCP-1 was positively associated with the duration of surgery (P = .016), whereas IL-6 levels increased with both the length (P < .001) and invasiveness of lung surgery (thoracoscopic wedge resection or lobectomy versus open lobectomy, P = .005; thoracoscopic wedge resection or lobectomy versus pneumonectomy, P = .021). In an exploratory approach, elevated IL-6 plasma peaks were associated with the occurrence of severe complications defined as Clavien-Dindo score grade ≥IVa during the postoperative phase up to 6 months after thoracic surgery (P = .006).

CONCLUSIONS

In summary, this substudy reveals factors, which correlate with high MCP-1 and IL-6 values. Moreover, higher IL-6 seems to be associated with postoperative severe complications. Perioperative IL-6 monitoring might be helpful for risk estimation in the perioperative setting of patients after lung surgery.

Impact of Chest Trauma and Overweight on Mortality and Outcome in Severely Injured Patients

The morbidity and mortality of severely injured patients are commonly affected by multiple factors. Especially, severe chest trauma has been shown to be a significant factor in considering outcome. Contemporaneously, weight-associated endocrinological, haematological, and metabolic deviations from the norm seem to have an impact on the posttraumatic course. Therefore, the aim of this study was to determine the influence of body weight on severely injured patients by emphasizing chest trauma. A total of 338 severely injured patients were included. Multivariate regression analyses were performed on patients with severe chest trauma (AIS ≥ 3) and patients with minor chest trauma (AIS < 3). The influence of body weight on in-hospital mortality was evaluated. Of all the patients, 70.4% were male, the median age was 52 years (IQR 36–68), the overall Injury Severity Score (ISS) was 24 points (IQR 17–29), and a median BMI of 25.1 points (IQR 23–28) was determined. In general, chest trauma was associated with prolonged ventilation, prolonged ICU treatment, and increased mortality. For overweight patients with severe chest trauma, an independent survival benefit was found (OR 0.158; p = 0.037). Overweight seems to have an impact on the mortality of severely injured patients with combined chest trauma. Potentially, a nutritive advantage or still-unknown immunological aspects in these patients affecting the intensive treatment course could be argued.

Impact of body mass index on outcomes after thoracic trauma-A matched-triplet analysis of the TraumaRegister DGU®

INTRODUCTION

Chest trauma and obesity are both associated with increased risks for respiratory complications (e.g. hypoxia, hypercarbia, pneumonia), which are frequent causes of posttraumatic morbidity and mortality. However, as there is only limited and inconsistent evidence, the aim of our study was to analyse the effect of body mass index (BMI) on patient outcomes after thoracic trauma.

PATIENTS AND METHODS

We screened 50.519 patients entered in TraumaRegister DGU^®, between 2004-2009, when the BMI was part of the standardized dataset. After matching for injury patterns and severity of trauma we performed a matched tripled analysis with regard to the BMI (group 1: <25.0 kg/m²; group 2: 25.0-29.9 kg/m²; group 3: >30.0 kg/m²). Data are shown as percentages and mean values with standard deviation.

RESULTS

The matching process yielded a cohort of 828 patients with serious blunt thoracic trauma, evenly distributed over the 3 BMI groups (276 triplets). BMI did not have an impact on the need for prehospital or emergency department interventions. There was a trend towards more liberal use of whole-body-CT scanning with increasing BMI (group 1: 68.8%; group 2: 73.2%; group 3: 75.0%). Additional abdominal injuries were more common in normal weight patients (Group 1: 28.3%; Group 2: 14.9%; Group 3: 17.8%). Obesity (BMI > 30.0 kg/m²) had a significant impact on the duration of mechanical ventilation (in days; group 1: 6.5 (9.4); group 2: 6.4 (8.9); group 3: 9.1 (14.4); p = 0.002), ICU days (in days; group 1: 11.5 (11.5); group 2: 10.9 (9.6); group 3: 14.1 (16.7); p = 0.005) and hospital length of stay (in days; group 1: 27.8 (19.3); group 2: 27.4 (19.2); group 3: 32.2 (25.9); p = 0.009). There were no significant differences regarding overall mortality (group 1: 3.6%; group 2: 1.8%; group 3: 4.0%; p = 0.26).

CONCLUSIONS

Obesity has a negative impact on outcomes after blunt chest trauma, as it is associated with prolonged duration of mechanical ventilation, ICU and hospital length of stay. Mortality did not seem to be affected, yet, further research is required to confirm these results in a larger cohort.

Increased Ratio of Visceral to Subcutaneous Adipose Tissue in Septic Patients Is Associated With Adverse Outcome

OBJECTIVES

Visceral and subcutaneous adipose tissue may contribute differentially to the septic inflammatory response. Accordingly, we tested the hypothesis that the ratio of visceral to subcutaneous adipose tissue is associated with altered sepsis outcome.

DESIGN

A retrospective analysis from a cohort of sepsis patients admitted between 2004 and 2009.

SETTING

A mixed medical-surgical ICU at St. Paul's Hospital in Vancouver, Canada.

PATIENTS

Patients older than 16 years old who had sepsis and underwent abdominal CT scan (n = 257) for clinical reasons.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

We measured the visceral adipose tissue and subcutaneous adipose tissue areas and calculated the visceral adipose tissue-to-subcutaneous adipose tissue ratio. Visceral adipose tissue/subcutaneous adipose tissue was not correlated with body mass index (r = -0.015, p = NS) and therefore provides additional unique information independent of body mass index. Sepsis patients with higher visceral adipose tissue/subcutaneous adipose tissue had greater 90-day mortality than patients with lower visceral adipose tissue/subcutaneous adipose tissue (log-rank test, linear-by linear association p < 0.005). After adjustment for significant covariates using Cox regression, increased visceral adipose tissue/subcutaneous adipose tissue quartile was significantly associated with increased 90-day mortality with hazard ratios of 2.01 (95% CI, 1.01-3.99) for the third visceral adipose tissue/subcutaneous adipose tissue quartile compared with the first quartile and 2.32 (95% CI, 1.15-4.69) for the highest visceral adipose tissue/subcutaneous adipose tissue quartile when compared with the first quartile. Increased mortality for patients with higher visceral adipose tissue/subcutaneous adipose tissue was found for both patients with body mass index less than 25 kg/m (p = 0.004) and for body mass index greater than or equal to 25 kg/m (p = 0.023). Furthermore, we found significantly greater need for mechanical ventilation, renal replacement therapy, and ICU stay in patients in the highest visceral adipose tissue/subcutaneous adipose tissue quartile. The ratio of proinflammatory (interleukin-8) to anti-inflammatory (interleukin-10) plasma cytokine levels was greater in patients with higher visceral adipose tissue/subcutaneous adipose tissue than in those with lower visceral adipose tissue/subcutaneous adipose tissue (p = 0.043).

CONCLUSIONS

Visceral obesity, defined by a high visceral adipose tissue-to-subcutaneous adipose tissue ratio, contributes to adverse outcome in sepsis patients perhaps because of a greater pro- versus anti-inflammatory response.

The Use of Redox Expression and Associated Molecular Damage to Evaluate the Inflammatory Response in Critically Ill Patient with Severe Burn

The patient with severe burns always represents a challenge for the trauma team due to the severe biochemical and physiopathological disorders. Although there are many resuscitation protocols of severe burn patient, systemic inflammatory response, oxidative stress, decreased immune response, infections, and multiple organ dysfunction syndromes are still secondary complications of trauma, present at maximum intensity in this type of patients. Currently there are numerous studies regarding the evaluation, monitoring, and minimizing the side effects induced by free radicals through antioxidant therapy. In this study, we want to introduce biochemical and physiological aspects of oxidative stress in patients with severe burns and to summarize the biomarkers used presently in the intensive care units. Systemic inflammations and infections are according to the literature the most important causes of death in these type of patients, being directly involved in multiple organ dysfunction syndrome and death.

Elite Control, Gut CD4 T Cell Sparing, and Enhanced Mucosal T Cell Responses in Macaca nemestrina Infected by a Simian Immunodeficiency Virus Lacking a gp41 Trafficking Motif

Deletion of Gly-720 and Tyr-721 from a highly conserved GYxxØ trafficking signal in the SIVmac239 envelope glycoprotein cytoplasmic domain, producing a virus termed ΔGY, leads to a striking perturbation in pathogenesis in rhesus macaques (Macaca mulatta). Infected macaques develop immune activation and progress to AIDS, but with only limited and transient infection of intestinal CD4(+) T cells and an absence of microbial translocation. Here we evaluated ΔGY in pig-tailed macaques (Macaca nemestrina), a species in which SIVmac239 infection typically leads to increased immune activation and more rapid progression to AIDS than in rhesus macaques. In pig-tailed macaques, ΔGY also replicated acutely to high peak plasma RNA levels identical to those for SIVmac239 and caused only transient infection of CD4(+) T cells in the gut lamina propria and no microbial translocation. However, in marked contrast to rhesus macaques, 19 of 21 pig-tailed macaques controlled ΔGY replication with plasma viral loads of <15 to 50 RNA copies/ml. CD4(+) T cells were preserved in blood and gut for up to 100 weeks with no immune activation or disease progression. Robust antiviral CD4(+) T cell responses were seen, particularly in the gut. Anti-CD8 antibody depletion demonstrated CD8(+) cellular control of viral replication. Two pig-tailed macaques progressed to disease with persisting viremia and possible compensatory mutations in the cytoplasmic tail. These studies demonstrate a marked perturbation in pathogenesis caused by ΔGY's ablation of the GYxxØ trafficking motif and reveal, paradoxically, that viral control is enhanced in a macaque species typically predisposed to more pathogenic manifestations of simian immunodeficiency virus (SIV) infection.

IMPORTANCE

The pathogenesis of human immunodeficiency virus (HIV) and simian immunodeficiency virus (SIV) reflects a balance between viral replication, host innate and adaptive antiviral immune responses, and sustained immune activation that in humans and Asian macaques is associated with persistent viremia, immune escape, and AIDS. Among nonhuman primates, pig-tailed macaques following SIV infection are predisposed to more rapid disease progression than are rhesus macaques. Here, we show that disruption of a conserved tyrosine-based cellular trafficking motif in the viral transmembrane envelope glycoprotein cytoplasmic tail leads in pig-tailed macaques to a unique phenotype in which high levels of acute viral replication are followed by elite control, robust cellular responses in mucosal tissues, and no disease. Paradoxically, control of this virus in rhesus macaques is only partial, and progression to AIDS occurs. This novel model should provide a powerful tool to help identify host-specific determinants for viral control with potential relevance for vaccine development.

Current Concepts in Orthopedic Management of Multiple Trauma

Multiple trauma patients frequently present challenging clinical scenarios with musculoskeletal injuries being the most common indications for surgical procedures in these patients. Despite our substantial knowledge, a universally approved objective definition for “multiple trauma” is yet to be delineated. Several controversial aspects of economics, pathophysiology, animal models, diagnosis, management and outcome of patients with multiple trauma have recently been explored and although some progress has been made, it seems that the available evidence is still inconclusive in some occasions. This manuscript revisits several current concepts of multiple trauma that have been the focus of recent investigation. We aim to provide the reader with an updated perspective based on the most recently published literature in the field of multiple trauma.

Use of miRNAs as biomarkers in sepsis

Sepsis is one of the most common causes of death in critical patients. Severe generalized inflammation, infections, and severe physiological imbalances significantly decrease the survival rate with more than 50%. Moreover, monitoring, evaluation, and therapy management often become extremely difficult for the clinician in this type of patients. Current methods of diagnosing sepsis vary based especially on the determination of biochemical-humoral markers, such as cytokines, components of the complement, and proinflammatory and anti-inflammatory compounds. Recent studies highlight the use of new biomarkers for sepsis, namely, miRNAs. miRNAs belong to a class of small, noncoding RNAs with an approximate content of 19-23 nucleotides. Following biochemical and physiological imbalances, the expression of miRNAs in blood or other body fluids changes significantly. Moreover, its stability, specificity, and selectivity make miRNAs ideal candidates for sepsis biomarkers. In conclusion, we can affirm that stable species of circulating miRNAs represent potential biomarkers for monitoring the evolution of sepsis.

Obesity-induced hyperleptinemia improves survival and immune response in a murine model of sepsis

BACKGROUND

Obesity is a growing health problem and associated with immune dysfunction. Sepsis is defined as systemic inflammatory response syndrome that occurs during infection. Excessive inflammation combined with immune dysfunction can lead to multiorgan damage and death.

METHODS

The authors investigated the influence of a class 1 obesity (body mass index between 30 and 34.9) on immune function and outcome in sepsis and the role of leptin on the immune response. The authors used a long-term high-fat-diet feeding model (12 weeks) on C57Bl/6 mice (n = 100) and controls on standard diet (n = 140) followed by a polymicrobial sepsis induced by cecal ligation and puncture.

RESULTS

The authors show that class 1 obesity is connected to significant higher serum leptin levels (data are mean ± SEM) (5.7 ± 1.2 vs. 2.7 ± 0.2 ng/ml; n = 5; P = 0.033) and improved innate immune response followed by significant better survival rate in sepsis (71.4%, n = 10 vs. 10%, n = 14; P < 0.0001). Additional sepsis-induced increases in leptin levels stabilize body temperature and are associated with a controlled immune response in a time-dependent and protective manner. Furthermore, leptin treatment of normal-weight septic mice with relative hypoleptinemia (n = 35) also significantly stabilizes body temperature, improves cellular immune response, and reduces proinflammatory cytokine response resulting in improved survival (30%; n = 10).

CONCLUSIONS

Relative hyperleptinemia of class 1 obesity or induced by treatment is protective in sepsis. Leptin seems to play a regulatory role in the immune system in sepsis, and treatment of relative hypoleptinemia could offer a new way of an individual sepsis therapy.