Global, regional, and national sepsis incidence and mortality, 1990-2017: analysis for the Global Burden of Disease Study

S1P lyase inhibition protects against sepsis by promoting disease tolerance via the S1P/S1PR3 axis

Background

One-third of all deaths in hospitals are caused by sepsis. Despite its demonstrated prevalence and high case fatality rate, antibiotics remain the only target-oriented treatment option currently available. Starting from results showing that low-dose anthracyclines protect against sepsis in mice, we sought to find new causative treatment options to improve sepsis outcomes.

Methods

Sepsis was induced in mice, and different treatment options were evaluated regarding cytokine and biomarker expression, lung epithelial cell permeability, autophagy induction, and survival benefit. Results were validated in cell culture experiments and correlated with patient samples.

Findings

Effective low-dose epirubicin treatment resulted in substantial downregulation of the sphingosine 1-phosphate (S1P) degrading enzyme S1P lyase (SPL). Consequent accumulation and secretion of S1P in lung parenchyma cells stimulated the S1P-receptor type 3 (S1PR3) and mitogen-activated protein kinases p38 and ERK, reducing tissue damage via increased disease tolerance. The protective effects of SPL inhibition were absent in S1PR3 deficient mice. Sepsis patients showed increased expression of SPL, stable expression of S1PR3, and increased levels of mucin-1 and surfactant protein D as indicators of lung damage.

Interpretation

Our work highlights a tissue-protective effect of SPL inhibition in sepsis due to activation of the S1P/S1PR3 axis and implies that SPL inhibitors and S1PR3 agonists might be potential therapeutics to protect against sepsis by increasing disease tolerance against infections.

Funding

This study was supported by the Center for Sepsis Control and Care (CSCC), the German Research Foundation (DFG), RTG 1715 (to M. H. G. and I. R.) and the National Institutes of Health, Grant R01GM043880 (to S. S.).

Glucocorticoids in Sepsis: To Be or Not to Be

Sepsis is a highly lethal syndrome resulting from dysregulated immune and metabolic responses to infection, thereby compromising host homeostasis. Activation of the hypothalamic–pituitary–adrenal (HPA) axis and subsequently adrenocortical glucocorticoid (GC) production during sepsis are important regulatory processes to maintain homeostasis. Multiple preclinical studies have proven the pivotal role of endogenous GCs in tolerance against sepsis by counteracting several of the sepsis characteristics, such as excessive inflammation, vascular defects, and hypoglycemia. Sepsis is however often complicated by dysfunction of the HPA axis, resulting from critical-illness-related corticosteroid insufficiency (CIRCI) and GC resistance. Therefore, GCs have been tested as an adjunctive therapy in sepsis and septic shock in different randomized clinical trials (RCTs). Nonetheless, these studies produced conflicting results. Interestingly, adding vitamin C and thiamin to GC therapy enhances the effects of GCs, probably by reducing GC resistance, and this results in an impressive reduction in sepsis mortality as was shown in two recent preliminary retrospective before–after studies. Multiple RCTs are currently underway to validate this new combination therapy in sepsis.

Sepsis in urology - where are we now? And where are we going?

CONTEXT

There has been heightened public awareness of the important issue of sepsis in the lay press in recent years with a focus on rapid detection and treatment. Within the field of Urology, how good are we at identifying, preventing and managing sepsis? Review: Reducing the morbidity and mortality associated with sepsis requires a multi-faceted approach including heightening awareness, prevention, early recognition of deterioration, escalation of care when necessary, implementation of antibiotic stewardship and the development of novel anti-microbial treatment strategies.

DISCUSSION

We review some of the aspects of sepsis management within our field that are working effectively and others that could potentially be optimised.

Changes in the incidence and prevalence of human immunodeficiency virus or acquired immunodeficiency syndrome in the South African medical schemes environment: 2005-2015

Background

The South African (SA) private medical schemes environment has over the past two decades respond to the evolving needs of people living with the human immunodeficiency virus (PLWH) or acquired immunodeficiency syndrome (AIDS).

Objective

To determine changes in the incidence and prevalence rate of human immunodeficiency virus (HIV) or AIDS in the SA private medical schemes environment from 2005 to 2015.

Method

In this observational study, a single, pharmaceutical benefit management (PBM) company’s medicine-claims database of members with HIV or AIDS has been retrospectively analysed from January 2005 to December 2015. The cohort includes all patients identified by the HIV or AIDS-related diagnostic ICD-10 codes, B20-B24, who also claimed antiretroviral medication during that period.

Results

From 2005 to 2015, the proportion of HIV or AIDS patients enrolled in the PBM-company increased from 0.63% to 2.10%, and the incidence rate of new cases among the beneficiaries increased 2.3 times. The highest HIV or AIDS prevalence and incidence rates were found in the age group ≥ 40 and < 60 years, followed by the age group ≥ 60 and < 70 years. The highest prevalence rates in 2015 were recorded in Gauteng, namely, 422.4/1000 beneficiaries, followed by Western Cape (149.4/1000), and KwaZulu-Natal (118.4/1000).

Conclusion

There has been an increase in the number of SA-PLWH accessing treatment in the medical scheme environment. The high prevalence of HIV infection among older members should signal concern that HIV-related comorbid conditions are likely to become a growing component of care required by PLWH utilizing the SA private healthcare sector.

Health-related quality of life in survivors of septic shock: 6-month follow-up from the ADRENAL trial

PURPOSE

To investigate the impact of hydrocortisone treatment and illness severity on health-related quality of life (HRQoL) at 6 months in septic shock survivors from the ADRENAL trial.

METHODS

Using the EuroQol questionnaire (EQ-5D-5L) at 6 months after randomization we assessed HRQoL in patient subgroups defined by hydrocortisone or placebo treatment, gender, illness severity (APACHE II < or ≥ 25), and severity of shock (baseline peak catecholamine doses < or ≥ 15 mcg/min). Additionally, in subgroups defined by post-randomisation variables; time to shock reversal (days), treatment with renal replacement therapy (RRT), and presence of bacteremia.

RESULTS

At 6 months, there were 2521 survivors. Of these 2151 patients (85.3%-1080 hydrocortisone and 1071 placebo) completed 6-month follow-up. Overall, at 6 months the mean EQ-5D-5L visual analogue scale (VAS) was 70.8, mean utility score 59.4. Between 15% and 30% of patients reported moderate to severe problems in any given HRQoL domain. There were no differences in any EQ-5D-5L domain in patients who received hydrocortisone vs. placebo, nor in the mean VAS (p = 0.6161), or mean utility score (p = 0.7611). In all patients combined, males experienced lower pain levels compared to females [p = 0.0002). Neither higher severity of illness or shock impacted reported HRQoL. In post-randomisation subgroups, longer time to shock reversal was associated with increased problems with mobility (p = < 0.0001]; self-care (p = 0.0.0142), usual activities (p = <0.0001] and pain (p = 0.0384). Amongst those treated with RRT, more patients reported increased problems with mobility (p = 0.0307) and usual activities (p = 0.0048) compared to those not treated. Bacteraemia was not associated with worse HRQoL in any domains of the EQ-5D-5L.

CONCLUSIONS

Approximately one fifth of septic shock survivors report moderate to extreme problems in HRQoL domains at 6 months. Hydrocortisone treatment for septic shock was not associated with improved HRQoL at 6 months. Female gender was associated with worse pain at 6 months.

Presenting Symptoms in Sepsis: Is the Mnemonic "SEPSIS" Useful?

Background

The mnemonic “SEPSIS” (S = Slurred speech or confusion, E = Extreme shivering or muscle pain, fever, P = Passing no urine all day, S = Severe breathlessness, I = It feels like you are going to die, S = Skin mottled or discolored) has been developed by the World Sepsis Day committee, so as to raise public awareness of the symptomatic presentation of sepsis. However, this mnemonic has not been validated.

Methods

A retrospective, observational, single-center study was performed. All adult septic patients presenting at the emergency department of Songklanagarind Hospital from 2016 to 2019 were included and followed up until either hospital discharge or death.

Results

The study included 437 patients, comprising patients with sepsis (n = 250) and those with septic shock (n = 187). Patients presented with symptoms according to the mnemonic as follows: S = 97 (22.2%), E = 240 (54.9%), P = 18 (4.1%), S =181 (41.4%), I = 5 (1.1%), and S = 5 (1.1%). Sixty-five patients (14.9%) did not present with any sepsis-specific symptoms according to the mnemonic. Compared with patients who had at least one mnemonic symptom, a higher proportion of patients without mnemonic symptoms had underlying immunosuppression (24.6% vs 8.3%, P < 0.01) and were diagnosed with intraabdominal infection (38.5% vs 12.1%, P < 0.01). In a multivariable adjusted logistic regression model, vague-presenting symptoms were independently associated with in-hospital mortality (adjusted odds ratio 2.17, 95% confidence interval 1.30−3.61, P = 0.03).

Conclusion

Two components of the mnemonic “SEPSIS” were rarely reported: it feels like you are going to die and skin mottled or discolored. Using the mnemonic might lead to missed diagnoses, especially in immunosuppression and intraabdominal infection. This mnemonic should be revised for the local context.

sTREM-1 predicts mortality in hospitalized patients with infection in a tropical, middle-income country

BACKGROUND

Few studies of biomarkers as predictors of outcome in infection have been performed in tropical, low- and middle-income countries where the burden of sepsis is highest. We evaluated whether selected biomarkers could predict 28-day mortality in infected patients in rural Thailand.

METHODS

Four thousand nine hundred eighty-nine adult patients admitted with suspected infection to a referral hospital in northeast Thailand were prospectively enrolled within 24 h of admission. In a secondary analysis of 760 patients, interleukin-8 (IL-8), soluble tumor necrosis factor receptor 1 (sTNFR-1), angiopoietin-1 (Ang-1), angiopoietin-2 (Ang-2), and soluble triggering receptor expressed by myeloid cells 1 (sTREM-1) were measured in the plasma. Association with 28-day mortality was evaluated using regression; a parsimonious biomarker model was selected using the least absolute shrinkage and selection operator (LASSO) method. Discrimination of mortality was assessed by receiver operating characteristic curve analysis and verified by multiple methods.

RESULTS

IL-8, sTNFR-1, Ang-2, and sTREM-1 concentrations were strongly associated with death. LASSO identified a three-biomarker model of sTREM-1, Ang-2, and IL-8, but sTREM-1 alone provided comparable mortality discrimination (p = 0.07). sTREM-1 alone was comparable to a model of clinical variables (area under receiver operating characteristic curve [AUC] 0.81, 95% confidence interval [CI] 0.77-0.85 vs AUC 0.79, 95% CI 0.74-0.84; p = 0.43). The combination of sTREM-1 and clinical variables yielded greater mortality discrimination than clinical variables alone (AUC 0.83, 95% CI 0.79-0.87; p = 0.004).

CONCLUSIONS

sTREM-1 predicts mortality from infection in a tropical, middle-income country comparably to a model derived from clinical variables and, when combined with clinical variables, can further augment mortality prediction.

TRIAL REGISTRATION

The Ubon-sepsis study was registered on ClinicalTrials.gov ( NCT02217592 ), 2014.

Illustrated State-of-the-Art Capsules of the ISTH 2020 Congress

The 2020 Congress of the International Society of Thrombosis and Haemostasis (ISTH) was held virtually July 12-15, 2019, due to the coronavirus disease 2019 pandemic. The congress convenes annually to discuss clinical and basic topics in hemostasis and thrombosis. Each year, the program includes State of Art (SOA) lectures given by prominent scientists. Presenters are asked to create Illustrated Capsules of their talks, which are concise illustrations with minimal explanatory text. Capsules cover major themes of the presentation, and these undergo formal peer review for inclusion in this article. Owing to the shift to a virtual congress this year, organizers reduced the program size. There were 39 SOA lectures virtually presented, and 29 capsules (9 from talks omitted from the virtual congress) were both submitted and successful in peer review, and are included in this article. Topics include the roles of the hemostatic system in inflammation, infection, immunity, and cancer, platelet function and signaling, platelet function disorders, megakaryocyte biology, hemophilia including gene therapy, phenotype tests in hemostasis, von Willebrand factor, anticoagulant factor V, computational driven discovery, endothelium, clinical and basic aspects of thrombotic microangiopathies, fibrinolysis and thrombolysis, antithrombotics in pediatrics, direct oral anticoagulant management, and thrombosis and hemostasis in pregnancy. Capsule authors invite virtual congress attendees to refer to these capsules during the live presentations and participate on Twitter in discussion. Research and Practice in Haemostasis and Thrombosis will release 2 tweets from @RPTHJournal during each presentation, using #IllustratedReview, #CoagCapsule and #ISTH2020. Readers are also welcome to utilize capsules for teaching and ongoing education.

The Role of Brain Natriuretic Peptide as a Prognostic Marker for Sepsis

Brain natriuretic peptide (BNP) is a neurohormone released in response to volume expansion and increased pressure. It is commonly used to assist in the diagnosis and management of heart failure. BNP can also play an important role as a biomarker in septic shock; however, elevations of BNP in conditions other than sepsis or cardiac dysfunction limits its use as the sole prognostic marker in patients hospitalized with sepsis. Further relationships regarding laboratory value and correlation with severity of illness need to be established with larger prospective studies to develop consensus regarding a cut-off point for optimum sensitivity and specificity in predicting in-hospital mortality related to sepsis.

The I-MICRO trial, Ilomedin for treatment of septic shock with persistent microperfusion defects: a double-blind, randomized controlled trial-study protocol for a randomized controlled trial

BACKGROUND

Septic shock remains a significant cause of death in critically ill patients. During septic shock, some patients will retain microcirculatory disorders despite optimal hemodynamic support (i.e., fluid resuscitation, vasopressors, inotropes). Alterations in the microcirculation are a key pathophysiological factor of organ dysfunction and death in septic shock patients. Ilomedin is a prostacyclin analog with vasodilatory effect and anti-thrombotic properties (i.e., inhibition of platelet aggregation) preferentially at the microcirculatory level. We hypothesize that early utilization of intravenous Ilomedin in septic shock patients with clinical persistence of microperfusion disorders would improve the recovery of organ dysfunction.

METHODS

The I-MICRO trial is a multicenter, prospective, randomized, double-blinded, placebo-controlled study. We plan to recruit 236 adult patients with septic shock and persistent microcirculatory disorders (i.e., skin mottling or increased capillary refill time) despite hemodynamic support. Participants will be randomized to receive a 48-h intravenous infusion of either Ilomedin or placebo starting at the earliest 6 h and later 24 h after septic shock. The primary outcome will be the change (delta) of sequential organ failure assessment (SOFA) score between randomization and day 7. Secondary outcomes will include mean SOFA score during the first 7 days after randomization, mortality at day 28 post-randomization, number of ventilation-free survival days in the 28 days post-randomization, number of renal replacement therapy-free survival days in the 28 days post-randomization, number of vasopressor-free survival days in the 28 days post-randomization, and mottling score at day 1 after randomization.

DISCUSSION

The trial aims to provide evidence on the efficacy and safety of Ilomedin in patients with septic shock and persistent microcirculatory disorders.

TRIAL REGISTRATION

NCT NCT03788837 . Registered on 28 December 2018.

Epidemiology and burden of sepsis acquired in hospitals and intensive care units: a systematic review and meta-analysis

PURPOSE

Sepsis is recognized as a global public health problem, but the proportion due to hospital-acquired infections remains unclear. We aimed to summarize the epidemiological evidence related to the burden of hospital-acquired (HA) and ICU-acquired (ICU-A) sepsis.

METHODS

We searched MEDLINE, Embase and the Global Index Medicus from 01/2000 to 03/2018. We included studies conducted hospital-wide or in intensive care units (ICUs), including neonatal units (NICUs), with data on the incidence/prevalence of HA and ICU-A sepsis and the proportion of community and hospital/ICU origin. We did random-effects meta-analyses to obtain pooled estimates; inter-study heterogeneity and risk of bias were assessed.

RESULTS

Of the 13,239 studies identified, 51 met the inclusion criteria; 22 were from low- and middle-income countries. Twenty-eight studies were conducted in ICUs, 13 in NICUs, and ten hospital-wide. The proportion of HA sepsis among all hospital-treated sepsis cases was 23.6% (95% CI 17-31.8%, range 16-36.4%). In the ICU, 24.4% (95% CI 16.7-34.2%, range 10.3-42.5%) of cases of sepsis with organ dysfunction were acquired during ICU stay and 48.7% (95% CI 38.3-59.3%, range 18.7-69.4%) had a hospital origin. The pooled hospital incidence of HA sepsis with organ dysfunction per 1000 patients was 9.3 (95% CI 7.3-11.9, range 2-20.6)). In the ICU, the pooled incidence of HA sepsis with organ dysfunction per 1000 patients was 56.5 (95% CI 35-90.2, range 9.2-254.4) and it was particularly high in NICUs. Mortality of ICU patients with HA sepsis with organ dysfunction was 52.3% (95% CI 43.4-61.1%, range 30.1-64.6%). There was a significant inter-study heterogeneity. Risk of bias was low to moderate in ICU-based studies and moderate to high in hospital-wide and NICU studies.

CONCLUSION

HA sepsis is of major public health importance, and the burden is particularly high in ICUs. There is an urgent need to improve the implementation of global and local infection prevention and management strategies to reduce its high burden among hospitalized patients.

Circular RNAs in Sepsis: Biogenesis, Function, and Clinical Significance

Sepsis is a life-threatening condition that occurs when the body responds to an infection that damages it is own tissues. The major problem in sepsis is rapid, vital status deterioration in patients, which can progress to septic shock with multiple organ failure if not properly treated. As there are no specific treatments, early diagnosis is mandatory to reduce high mortality. Despite more than 170 different biomarkers being postulated, early sepsis diagnosis and prognosis remain a challenge for clinicians. Recent findings propose that circular RNAs (circRNAs) may play a prominent role in regulating the patients’ immune system against different pathogens, including bacteria and viruses. Mounting evidence also suggests that the misregulation of circRNAs is an early event in a wide range of diseases, including sepsis. Despite circRNA levels being altered in sepsis, the specific mechanisms controlling the dysregulation of these noncoding RNAs are not completely elucidated, although many factors are known to affect circRNA biogenesis. Therefore, there is a need to explore the molecular pathways that lead to this disorder. This review describes the role of this new class of regulatory RNAs in sepsis and the feasibility of using circRNAs as diagnostic biomarkers for sepsis, opening up new avenues for circRNA-based medicine.

Utility of Procalcitonin as a Biomarker for Sepsis in Children

Sepsis is a complex process defined as life-threatening organ dysfunction caused by a dysregulated host response to infection. It is associated with significant morbidity and mortality rates in both adults and children, and emphasis has been placed on its early recognition and prompt provision of antimicrobials. Owing to limitations of current diagnostic tests (i.e., poor sensitivity and delayed results), significant research has been conducted to identify sepsis biomarkers. Ideally, a biomarker could reliably and rapidly distinguish bacterial infection from other, noninfectious causes of systemic inflammatory illness. In doing so, a sepsis biomarker could be used for earlier identification of sepsis, risk stratification/prognostication, and/or guidance of antibiotic decision-making. In this minireview, we review one of the most common clinically used sepsis biomarkers, procalcitonin, and its roles in sepsis management in these three areas. We highlight key findings in the adult literature but focus the bulk of this review on pediatric sepsis. The challenges and limitations of procalcitonin measurement in sepsis are also discussed.

Elevated body mass index is associated with an increased risk of infectious disease admissions and mortality: a mendelian randomization study

OBJECTIVE

The effect of body mass index (BMI) on the risk of infectious diseases admissions and mortality is unclear and is difficult to study given the risks of confounding variables.

METHODS

We used genome-wide association studies (GWASs) with mendelian randomization (MR) to obtain causal inference of BMI on the following infectious diseases outcomes: hospital admissions for pneumonia, sepsis, urinary tract infections, skin and soft tissue infections (SSTIs) or all-cause infections. For patients with pneumonia and sepsis, we also analysed their 28-day and 90-day mortalities. The UK Biobank (UKB) cohort (n > 500 000) provided data for GWASs on infectious diseases. The GIANT consortium (n = 681 265) GWAS was used to identify single-nucleotide polymorphisms (SNPs) associated with BMI.

RESULTS

Genetically increased BMI, by one standard deviation, was associated with higher rates of admission due to all infectious disease. The effect was most important for SSTIs (OR: 1.11, 95%CI: 1.09, 1.12). Increasing BMI by one standard deviation was associated with higher pneumonia mortality, especially at 28 days (OR: 1.03, 95%CI: 1.01, 1.05). BMI was not clearly associated with sepsis mortality, although interpretation of the results was limited by a small sample size. There were consistent findings in sensitivity analysis performed by removing highly pleiotropic SNPs and multivariate MR including type-2 diabetes mellitus, estimated glomerular filtration rate, high-density lipoprotein, educational attainment, and a history of smoking.

CONCLUSIONS

Increased BMI was associated with increased risk of admission for infectious disease and mortality. While the pathophysiology behind this phenomenon remains unknown, increasing BMI may influence immune dysregulation.

Hydrogen Gas Alleviates Sepsis-Induced Brain Injury by Improving Mitochondrial Biogenesis Through the Activation of PGC-α in Mice

ABSTRACT

Sepsis-associated encephalopathy (SAE) affects approximately one-third of septic patients, and there is a lack of effective therapeutics for SAE. Hydrogen gas is a new medical gas that exerts anti-inflammation, antioxidation, and anti-apoptotic effects and can effectively protect septic mice. Mitochondrial dysfunction, which can be improved by mitochondrial biogenesis, is a type of molecular pathology in sepsis. Peroxisome proliferator-activated receptor gamma co-activator 1α (PGC-1α), which can be inhibited by SR-18292, is the key regulatory factor of mitochondrial biogenesis. Therefore, we investigated the effects of hydrogen gas on mitochondrial function and mitochondrial biogenesis in mice with SAE and the related regulatory mechanisms. Cecal ligation and puncture was used to induce sepsis in mice. The mice with hydrogen gas therapy were exposed to 2% H2 inhalation for 1 h beginning at both 1 and 6 h after operation, and mice were also injected with a PGC-1α inhibitor, SR-18292. We recorded the 7-day survival rates of the mice and detected their cognitive function using a Y-maze test. The Nissl bodies in the CA1 region of hippocampus were observed by Nissl staining, and the apoptotic cells were observed by terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling assay staining. The mitochondrial membrane potential (MMP), adenosine triphosphate (ATP) level, and mitochondrial respiratory chain complexes I and II were analyzed using commercial kits. The mitochondrial morphology was observed by transmission electron microscopy. The expression levels of PGC-1α, nuclear respiratory factor 2 (NRF2), and mitochondrial transcription factor A (Tfam) were detected by Western blot analysis. The present study showed that hydrogen gas therapy increased the 7-day survival rate, improved cognitive function, increased the mitochondrial function (MMP, ATP level, complex I activity) and expression of mitochondrial biogenesis parameters (PGC-1α, NRF2, Tfam). However, the injection of SR-18292 (a PGC-1α inhibitor) decreased mitochondrial function, PGC-1α activation, and expression of NRF2 and Tfam. Therefore, these results indicate that hydrogen gas alleviates sepsis-induced brain injury in mice by improving mitochondrial biogenesis through the activation of PGC-1α.

Incidence and mortality of hospital- and ICU-treated sepsis: results from an updated and expanded systematic review and meta-analysis

Purpose

To investigate the global burden of sepsis in hospitalized adults by updating and expanding a systematic review and meta-analysis and to compare findings with recent Institute for Health Metrics and Evaluation (IHME) sepsis estimates.

Methods

Thirteen electronic databases were searched for studies on population-level sepsis incidence defined according to clinical criteria (Sepsis-1, -2: severe sepsis criteria, or sepsis-3: sepsis criteria) or relevant ICD-codes. The search of the original systematic review was updated for studies published 05/2015–02/2019 and complemented by a search targeting low- or middle-income-country (LMIC) studies published 01/1979–02/2019. We performed a random-effects meta-analysis with incidence of hospital- and ICU-treated sepsis and proportion of deaths among these sepsis cases as outcomes.

Results

Of 4746 results, 28 met the inclusion criteria. 21 studies contributed data for the meta-analysis and were pooled with 30 studies from the original meta-analysis. Pooled incidence was 189 [95% CI 133, 267] hospital-treated sepsis cases per 100,000 person-years. An estimated 26.7% [22.9, 30.7] of sepsis patients died. Estimated incidence of ICU-treated sepsis was 58 [42, 81] per 100,000 person-years, of which 41.9% [95% CI 36.2, 47.7] died prior to hospital discharge. There was a considerably higher incidence of hospital-treated sepsis observed after 2008 (+ 46% compared to the overall time frame).

Conclusions

Compared to results from the IHME study, we found an approximately 50% lower incidence of hospital-treated sepsis. The majority of studies included were based on administrative data, thus limiting our ability to assess temporal trends and regional differences. The incidence of sepsis remains unknown for the vast majority of LMICs, highlighting the urgent need for improved epidemiological sepsis surveillance.

Electronic supplementary material

The online version of this article (10.1007/s00134-020-06151-x) contains supplementary material, which is available to authorized users.

Biomarkers and Associated Immune Mechanisms for Early Detection and Therapeutic Management of Sepsis

Sepsis is conceptually defined as life-threatening organ dysfunction that is caused by a dysregulated host response to infection. Although there has been significant advancement in recent decades in defining and understanding sepsis pathology, clinical management of sepsis is challenging due to difficulties in diagnosis, a lack of reliable prognostic biomarkers, and treatment options that are largely limited to antibiotic therapy and fundamental supportive measures. The lack of reliable diagnostic and prognostic tests makes it difficult to triage patients who are in need of more urgent care. Furthermore, while the acute inpatient treatment of sepsis warrants ongoing attention and investigation, efforts must also be directed toward longer term survival and outcomes. Sepsis survivors experience incomplete recovery, with long-term health impairments that may require both cognitive and physical treatment and rehabilitation. This review summarizes recent advances in sepsis prognosis research and discusses progress made in elucidating the underlying causes of prolonged health deficits experienced by patients surviving the early phases of sepsis.

Dietary micronutrients in the wake of COVID-19: an appraisal of evidence with a focus on high-risk groups and preventative healthcare

Existing micronutrient deficiencies, even if only a single micronutrient, can impair immune function and increase susceptibility to infectious disease. Certain population groups are more likely to have micronutrient deficiencies, while certain disease pathologies and treatment practices also exacerbate risk, meaning these groups tend to suffer increased morbidity and mortality from infectious diseases. Optimisation of overall nutritional status, including micronutrients, can be effective in reducing incidence of infectious disease. Micronutrient deficiencies are rarely recognised but are prevalent in the UK, as well as much more widely, particularly in high-risk groups susceptible to COVID-19. Practitioners should be aware of this fact and should make it a consideration for the screening process in COVID-19, or when screening may be difficult or impractical, to ensure blanket treatment as per the best practice guidelines. Correction of established micronutrient deficiencies, or in some cases assumed suboptimal status, has the potential to help support immune function and mitigate risk of infection. The effects of and immune response to COVID-19 share common characteristics with more well-characterised severe acute respiratory infections. Correction of micronutrient deficiencies has proven effective in several infectious diseases and has been shown to promote favourable clinical outcomes. Micronutrients appear to play key roles in mediating the inflammatory response and such effects may be enhanced through correction of deficiencies. Many of those at highest risk during the COVID-19 pandemic are also populations at highest risk of micronutrient deficiencies and poorer overall nutrition. Correction of micronutrient deficiencies in established COVID-19 infection may contribute to supporting immune response to infection in those at highest risk. There is a need for further research to establish optimal public health practice and clinical intervention regimens.

The Multifaceted Function of Granzymes in Sepsis: Some Facts and a Lot to Discover

Sepsis is a serious global health problem. In addition to a high incidence, this syndrome has a high mortality and is responsible for huge health expenditure. The pathophysiology of sepsis is very complex and it is not well-understood yet. However, it is widely accepted that the initial phase of sepsis is characterized by a hyperinflammatory response while the late phase is characterized by immunosuppression and immune anergy, increasing the risk of secondary infections. Granzymes (Gzms) are a family of serine proteases classified according to their cleavage specificity. Traditionally, it was assumed that all Gzms acted as cytotoxic proteases. However, recent evidence suggests that GzmB is the one with the greatest cytotoxic capacity, while the cytotoxicity of others such as GzmA and GzmK is not clear. Recent studies have found that GzmA, GzmB, GzmK, and GzmM act as pro-inflammatory mediators. Specially, solid evidences show that GzmA and GzmK function as extracellular proteases that regulate the inflammatory response irrespectively of its ability to induce cell death. Indeed, studies in animal models indicate that GzmA is involved in the cytokine release syndrome characteristic of sepsis. Moreover, the GZM family also could regulate other biological processes involved in sepsis pathophysiology like the coagulation cascade, platelet function, endothelial barrier permeability, and, in addition, could be involved in the immunosuppressive stage of sepsis. In this review, we provide a comprehensive overview on the contribution of these novel functions of Gzms to sepsis and the new therapeutic opportunities emerging from targeting these proteases for the treatment of this serious health problem.

Pediatric Sepsis Definition-A Systematic Review Protocol by the Pediatric Sepsis Definition Taskforce

Supplemental Digital Content is available in the text.

Sepsis is responsible for a substantial proportion of global childhood morbidity and mortality. However, evidence demonstrates major inaccuracies in the use of the term “sepsis” in clinical practice, coding, and research. Current and previous definitions of sepsis have been developed using expert consensus but the specific criteria used to identify children with sepsis have not been rigorously evaluated. Therefore, as part of the Society of Critical Care Medicine’s Pediatric Sepsis Definition Taskforce, we will conduct a systematic review to synthesize evidence on individual factors, clinical criteria, or illness severity scores that may be used to identify children with infection who have or are at high risk of developing sepsis-associated organ dysfunction and separately those factors, criteria, and scores that may be used to identify children with sepsis who are at high risk of progressing to multiple organ dysfunction or death.

IGF-1 Deficiency Rescue and Intracellular Calcium Blockade Improves Survival and Corresponding Mechanisms in a Mouse Model of Acute Kidney Injury

This study was undertaken to test two therapies for acute kidney injury (AKI) prevention, IGF-1, which is renal protective, and BTP-2, which is a calcium entry (SOCE) inhibitor. We utilized lipopolysaccharide (LPS) IP, as a systemic model of AKI and studied in five groups of animals. Three experiments showed that at 7 days: (1) LPS significantly reduced serum IGF-1 and intramuscular IGF-I in vivo gene therapy rescued this deficiency. (2) Next, at the 7-day time point, our combination therapy, compared to the untreated group, caused a significant increase in survival, which was noteworthy because all of the untreated animals died in 72 h. (3) The four pathways associated with inflammation, including (A) increase in cytosolic calcium, (B) elaboration of proinflammatory cytokines, (C) impairment of vascular integrity, and (D) cell injury, were adversely affected in renal tissue by LPS, using a sublethal dose of LPS. The expression of several genes was measured in each of the above pathways. The combined therapy of IGF-1 and BTP-2 caused a favorable gene expression response in all four pathways. Our current study was an AKI study, but these pathways are also involved in other types of severe inflammation, including sepsis, acute respiratory distress syndrome, and probably severe coronavirus infection.

Phagocytosis-Inflammation Crosstalk in Sepsis: New Avenues for Therapeutic Intervention

Phagocytosis is a complex process by which cells within most organ systems remove pathogens and cell debris. Phagocytosis is usually followed by inflammatory pathway activation, which promotes pathogen elimination and inhibits pathogen growth. Delayed pathogen elimination is the first step in sepsis development and a key factor in sepsis resolution. Phagocytosis thus has an important role during sepsis and likely contributes to all of its clinical stages. However, only a few studies have specifically explored and characterized phagocytic activity during sepsis. Here, we describe the phagocytic processes that occur as part of the immune response preceding sepsis onset and identify the elements of phagocytosis that might constitute a predictive marker of sepsis outcomes. First, we detail the key features of phagocytosis, including the main receptors and signaling hallmarks associated with different phagocytic processes. We then discuss how the initial events of phagosome formation and cytoskeletal remodeling might be associated with known sepsis features, such as a cytokine-driven hyperinflammatory response and immunosuppression. Finally, we highlight the unresolved mechanisms of sepsis development and progression and the need for cross-disciplinary approaches to link the clinical complexity of the disease with basic cellular and molecular mechanisms.

New EUCAST definitions of S, I and R from 2019 - German physicians are largely not aware of the changes

PURPOSE

On January 1st 2019, the new EUCAST definitions of susceptibility testing categories S, I and R took effect. The changes in the I category have considerable clinical impact because they lead to major changes in the antibiogram, and misinterpretation may result in inappropriate selection and dosing of antibiotics hampering effective treatment of infectious diseases. We assessed if German physicians are aware of the new definitions and their consequences.

METHODS

We conducted a nationwide web-based survey to assess the knowledge on the new definitions of S, I and R. The survey was addressed to clinicians across all medical specialties working in Germany and was open from May 9th to July 30th 2019.

RESULTS

The answers of 902 participants were included in the analysis. Most participants were employed at hospitals (79.3%) and had already completed specialist training (86.1%). The predominant specialty was internal medicine (50.6%). Of all participants, 45.7% did not know that there was a change in the definitions of S, I and R, and 65.4% did not feel well-informed about the changes. When the participants had to identify true and false statements regarding the new I, substantial knowledge gaps were apparent. Worst results were achieved by those physicians who are not employed in a hospital but work in their own practice.

CONCLUSION

Our survey shows that German physicians are insufficiently informed about the new definitions of S, I and R. Further education is strongly needed to ensure optimal treatment of infectious diseases.

Recommendations for fluid management of adults with sepsis in sub-Saharan Africa: a systematic review of guidelines

BACKGROUND

Sepsis guidelines are widely used in high-income countries and intravenous fluids are an important supportive treatment modality. However, fluids have been harmful in intervention trials in low-income countries, most notably in sub-Saharan Africa. We assessed the relevance, quality and applicability of available guidelines for the fluid management of adult patients with sepsis in this region.

METHODS

We identified sepsis guidelines by systematic review with broad search terms, duplicate screening and data extraction. We included peer-reviewed publications with explicit relevance to sepsis and fluid therapy. We excluded those designed exclusively for specific aetiologies of sepsis, for limited geographic locations, or for non-adult populations. We used the AGREE II tool to assess the quality of guideline development, performed a narrative synthesis and used theoretical case scenarios to assess practical applicability to everyday clinical practice in resource-constrained settings.

RESULTS

Published sepsis guidelines are heterogeneous in sepsis definition and in quality: 8/10 guidelines had significant deficits in applicability, particularly with reference to resource considerations in low-income settings. Indications for intravenous fluid were hypotension (8/10), clinical markers of hypoperfusion (6/10) and lactataemia (3/10). Crystalloids were overwhelmingly recommended (9/10). Suggested volumes varied; 5/10 explicitly recommended "fluid challenges" with reassessment, totalling between 1 L and 4 L during initial resuscitation. Fluid balance, including later de-escalation of therapy, was not specifically described in any. Norepinephrine was the preferred initial vasopressor (5/10), specifically targeted to MAP > 65 mmHg (3/10), with higher values suggested in pre-existing hypertension (1/10). Recommendations for guidelines were almost universally derived from evidence in high-income countries. None of the guidelines suggested any refinement for patients with malnutrition.

CONCLUSIONS

Widely used international guidelines contain disparate recommendations on intravenous fluid use, lack specificity and are largely unattainable in low-income countries given available resources. A relative lack of high-quality evidence from sub-Saharan Africa increases reliance on recommendations which may not be relevant or implementable.

Relevance of anaerobic bacteremia in adult patients: A never-ending story?

Obligate anaerobic bacteria are considered important constituents of the microbiota of humans; in addition, they are also important etiological agents in some focal or invasive infections and bacteremia with a high level of mortality. Conflicting data have accumulated over the last decades regarding the extent in which these pathogens play an intrinsic role in bloodstream infections. Clinical characteristics of anaerobic bloodstream infections do not differ from bacteremia caused by other pathogens, but due to their longer generation time and rigorous growth requirements, it usually takes longer to establish the etiological diagnosis. The introduction of matrix-assisted laser desorption-ionization time-of-flight mass spectrometry (MALDI-TOF MS) has represented a technological revolution in microbiological diagnostics, which has allowed for the fast, accurate and reliable identification of anaerobic bacteria at a low sample cost. The purpose of this review article is to summarize the currently available literature data on the prevalence of anaerobic bacteremia in adults for physicians and clinical microbiologists and to shed some light on the complexity of this topic nowadays.

IFNL3 rs12980275 Polymorphism Predicts Septic Shock-Related Death in Patients Undergoing Major Surgery: A Retrospective Study

Interferon lambda 3 (IFNL3, previously called IL-28B) is a cytokine with effects against viral and bacterial pathogens. We aimed to analyze the IFNL3 rs12980275 SNP in patients who underwent major surgery, in order to establish its relationship with susceptibility to septic shock and septic shock-related death in these patients. We performed a case-control study on 376 patients to establish the association between IFNL3 rs12980275 SNP and the susceptibility to develop septic shock. Besides, we performed a longitudinal study among 172 septic shock patients using survival analysis with one censoring point of 28-days mortality. The IFNL3 rs12980275 polymorphism was genotyped by Agena Bioscience's MassARRAY platform. IFNL3 rs12980275 polymorphism was not associated with higher susceptibility to infection and septic shock development. Regarding survival analysis, the Kaplan–Meier analysis showed that patients with IFNL3 rs12980275 AA genotype had higher survival than patients with GG genotype (p = 0.003). The Cox regression analysis adjusted by the most relevant clinical and epidemiological characteristics showed that the GG genotype (recessive model) and the presence of the G allele (additive model) were associated with higher risk of death [adjusted hazard ratio (aHR) = 2.15, p = 0.034; aHR = 1.50, p = 0.030, respectively]. In conclusion, IFNL3 rs12980275 polymorphism was associated with septic shock-related death in patients who underwent major surgery. The A allele was linked to protection, and the G allele was associated with an increased risk of death. This is a first preliminary study that suggests for the first time a role of IFNL3 polymorphisms in the prognosis of septic shock.

Whole blood transcriptional responses of very preterm infants during late-onset sepsis

BACKGROUND

Host immune responses during late-onset sepsis (LOS) in very preterm infants are poorly characterised due to a complex and dynamic pathophysiology and challenges in working with small available blood volumes. We present here an unbiased transcriptomic analysis of whole peripheral blood from very preterm infants at the time of LOS.

METHODS

RNA-Seq was performed on peripheral blood samples (6-29 days postnatal age) taken at the time of suspected LOS from very preterm infants <30 weeks gestational age. Infants were classified based on blood culture positivity and elevated C-reactive protein concentrations as having confirmed LOS (n = 5), possible LOS (n = 4) or no LOS (n = 9). Bioinformatics and statistical analyses performed included pathway over-representation and protein-protein interaction network analyses. Plasma cytokine immunoassays were performed to validate differentially expressed cytokine pathways.

RESULTS

The blood leukocyte transcriptional responses of infants with confirmed LOS differed significantly from infants without LOS (1,317 differentially expressed genes). However, infants with possible LOS could not be distinguished from infants with no LOS or confirmed LOS. Transcriptional alterations associated with LOS included genes involved in pathogen recognition (mainly TLR pathways), cytokine signalling (both pro-inflammatory and inhibitory responses), immune and haematological regulation (including cell death pathways), and metabolism (altered cholesterol biosynthesis). At the transcriptional-level cytokine responses during LOS were characterised by over-representation of IFN-α/β, IFN-γ, IL-1 and IL-6 signalling pathways and up-regulation of genes for inflammatory responses. Infants with confirmed LOS had significantly higher levels of IL-1α and IL-6 in their plasma.

CONCLUSIONS

Blood responses in very preterm infants with LOS are characterised by altered host immune responses that appear to reflect unbalanced immuno-metabolic homeostasis.

Nangibotide in patients with septic shock: a Phase 2a randomized controlled clinical trial

PURPOSE

Nangibotide is a specific TREM-1 inhibitor that tempered deleterious host-pathogens interactions, restored vascular function, and improved survival, in animal septic shock models. This study evaluated the safety and pharmacokinetics of nangibotide and its effects on clinical and pharmacodynamic parameters in septic shock patients.

METHODS

This was a multicenter randomized, double-blind, two-stage study. Patients received either continuous infusion of nangibotide (0.3, 1.0, or 3.0 mg/kg/h) or placebo. Treatment began < 24 h after shock onset and continued for up to 5 days. Safety primary outcomes were adverse events (AEs), whether serious or not, and death. Exploratory endpoints evaluated nangibotide effects on pharmacodynamics, organ function, and mortality, and were analyzed according to baseline sTREM-1 concentrations.

RESULTS

Forty-nine patients were randomized. All treatment emergent AEs (TEAEs) were collected until Day 28. No significant differences were observed in TEAEs between treatment groups. No drug withdrawal linked to TEAE nor appearance of anti-drug antibodies were reported. Nangibotide pharmacokinetics appeared to be dose-proportional and clearance was dose-independent. Nangibotide did not significantly affect pharmacodynamic markers. Decrease in SOFA score LS mean change (± SE) from baseline to Day 5 in pooled nangibotide groups versus placebo was - 0.7 (± 0.85) in the randomized population and - 1.5 (± 1.12) in patients with high baseline plasma sTREM-1 concentrations (non-significant). This pattern was similar to organ support end points.

CONCLUSION

No significant increases in TEAEs were detected in nangibotide-treated patients versus placebo. These results encourage further evaluation of nangibotide and further exploration of plasma sTREM-1 concentrations as a predictive efficacy biomarker.

Epidemiological Trend of Sepsis in Patients with Hospital Admissions Related to Hepatitis C in Spain (2000-2015): A Nationwide Study

Background: Hepatitis C virus (HCV) infection predisposes patients to other infectious diseases, such as sepsis. We aimed to analyze epidemiological trends of sepsis-related admissions, deaths, and costs in hospital admissions with chronic hepatitis C who had a hospital admission in Spain. Methods: We performed a retrospective study of all hospitalizations involving chronic hepatitis C in the Spanish Minimum Basic Data Set (MBDS) between 2000 and 2015. This period was divided into four calendar periods (2000–2004, 2005–2007, 2008–2011, and 2012–2015). Results: We selected 868,523 hospital admissions of patients with chronic hepatitis C over 16 years in the Spanish MBDS. Among them, we found 70,976 (8.17%) hospital admissions of patients who developed sepsis, of which 13,915 (19.61%) died during admission. We found an upward trend, from 2000–2003 to 2012–2015, in the rate of sepsis-related admission (from 6.18% to 10.64%; p < 0.001), the risk of sepsis-related admission (from 1.31 to 1.55; p < 0.001), and the sepsis-related cost per hospital admission (from 7198€ to above 9497€; p < 0.001). However, we found a downward trend during the same study period in the sepsis case-fatality rate (from 21.99% to 18.16%; p < 0.001), the risk of sepsis-related death (from 0.81 to 0.56; p < 0.001), and the length of hospital stay (LOHS) (from 16.9 to 13.9; p < 0.001). Moreover, the rate of bacterial Gram-positive and candidiasis infections decreased, while Gram-negative microorganisms increased from 2000–2003 to 2012–2015. Conclusions: Sepsis, in chronic hepatitis C patients admitted to the hospital, has increased the period 2000–2015 and has been an increasing burden for the Spanish public health system. However, there has also been a significant reduction in lethality and LOHS during the study period. In addition, the most prevalent specific microorganisms have also changed in this period.

Antibody Production in Murine Polymicrobial Sepsis-Kinetics and Key Players

Although antigen-specific priming of antibody responses is impaired during sepsis, there is nevertheless a strong increase in IgM and IgG serum concentrations. Using colon ascendens stent peritonitis (CASP), a mouse model of polymicrobial abdominal sepsis, we observed substantial increases in IgM as well as IgG of all subclasses, starting at day 3 and peaking 2 weeks after sepsis induction. The dominant source of antibody-secreting cells was by far the spleen, with a minor contribution of the mesenteric lymph nodes. Remarkably, sepsis induction in splenectomized mice did not change the dynamics of the serum IgM/IgG reaction, indicating that the marginal zone B cells, which almost exclusively reside in the spleen, are dispensable in such a setting. Hence, in systemic bacterial infection, the function of the spleen as dominant niche of antibody-producing cells can be compensated by extra-splenic B cell populations as well as other lymphoid organs. Depletion of CD4+ T cells did not affect the IgM response, while it impaired IgG generation of all subclasses with the exception of IgG3. Taken together, our data demonstrate that the robust class-switched antibody response in sepsis encompasses both T cell-dependent and -independent components.

EcDBS1R6: A novel cationic antimicrobial peptide derived from a signal peptide sequence

BACKGROUND

Bacterial infections represent a major worldwide health problem the antimicrobial peptides (AMPs) have been considered as potential alternative agents for treating these infections. Here we demonstrated the antimicrobial activity of EcDBS1R6, a peptide derived from a signal peptide sequence of Escherichia coli that we previously turned into an AMP by making changes through the Joker algorithm.

METHODS

Antimicrobial activity was measured by broth microdilution method. Membrane integrity was measured using fluorescent probes and through scanning electron microscopy imaging. A sliding window of truncated peptides was used to determine the EcDBS1R6 active core. Molecular dynamics in TFE/water environment was used to assess the EcDBS1R6 structure.

RESULTS

Signal peptides are known to naturally interact with membranes; however, the modifications introduced by Joker transformed this peptide into a membrane-active agent capable of killing bacteria. The C-terminus was unable to fold into an α-helix whereas its fragments showed poor or no antimicrobial activity, suggesting that the EcDBS1R6 antibacterial core was located at the helical N-terminus, corresponding to the signal peptide portion of the parent peptide.

CONCLUSION

The strategy of transforming signal peptides into AMPs appears to be promising and could be used to produce novel antimicrobial agents.

GENERAL SIGNIFICANCE

The process of transforming an inactive signal peptide into an antimicrobial peptide could open a new venue for creating new AMPs derived from signal peptides.

2-Chlorofatty acids are biomarkers of sepsis mortality and mediators of barrier dysfunction in rats

Sepsis is defined as the systemic, dysregulated host immune response to an infection that leads to injury to host organ systems and, often, death. Complex interactions between pathogens and their hosts elicit microcirculatory dysfunction. Neutrophil myeloperoxidase (MPO) is critical for combating pathogens, but MPO-derived hypochlorous acid (HOCl) can react with host molecular species as well. Plasmalogens are targeted by HOCl, leading to the production of 2-chlorofatty acids (2-CLFAs). 2-CLFAs are associated with human sepsis mortality, decrease in vitro endothelial barrier function, and activate human neutrophil extracellular trap formation. Here, we sought to examine 2-CLFAs in an in vivo rat sepsis model. Intraperitoneal cecal slurry sepsis with clinically relevant rescue therapies led to ∼73% mortality and evidence of microcirculatory dysfunction. Plasma concentrations of 2-CLFAs assessed 8 h after sepsis induction were lower in rats that survived sepsis than in nonsurvivors. 2-CLFA levels were elevated in kidney, liver, spleen, lung, colon, and ileum in septic animals. In vivo, exogenous 2-CLFA treatments increased kidney permeability, and in in vitro experiments, 2-CLFA also increased epithelial surface expression of vascular cell adhesion molecule 1 and decreased epithelial barrier function. Collectively, these studies support a role of free 2-CLFAs as biomarkers of sepsis mortality, potentially mediated, in part, by 2-CLFA-elicited endothelial and epithelial barrier dysfunction.

Optimal Nutritional Status for a Well-Functioning Immune System Is an Important Factor to Protect against Viral Infections

Public health practices including handwashing and vaccinations help reduce the spread and impact of infections. Nevertheless, the global burden of infection is high, and additional measures are necessary. Acute respiratory tract infections, for example, were responsible for approximately 2.38 million deaths worldwide in 2016. The role nutrition plays in supporting the immune system is well-established. A wealth of mechanistic and clinical data show that vitamins, including vitamins A, B6, B12, C, D, E, and folate; trace elements, including zinc, iron, selenium, magnesium, and copper; and the omega-3 fatty acids eicosapentaenoic acid and docosahexaenoic acid play important and complementary roles in supporting the immune system. Inadequate intake and status of these nutrients are widespread, leading to a decrease in resistance to infections and as a consequence an increase in disease burden. Against this background the following conclusions are made: (1) supplementation with the above micronutrients and omega-3 fatty acids is a safe, effective, and low-cost strategy to help support optimal immune function; (2) supplementation above the Recommended Dietary Allowance (RDA), but within recommended upper safety limits, for specific nutrients such as vitamins C and D is warranted; and (3) public health officials are encouraged to include nutritional strategies in their recommendations to improve public health.

Prevalence and Outcomes of Infection Among Patients in Intensive Care Units in 2017

IMPORTANCE

Infection is frequent among patients in the intensive care unit (ICU). Contemporary information about the types of infections, causative pathogens, and outcomes can aid the development of policies for prevention, diagnosis, treatment, and resource allocation and may assist in the design of interventional studies.

OBJECTIVE

To provide information about the prevalence and outcomes of infection and the available resources in ICUs worldwide.

DESIGN, SETTING, AND PARTICIPANTS

Observational 24-hour point prevalence study with longitudinal follow-up at 1150 centers in 88 countries. All adult patients (aged ≥18 years) treated at a participating ICU during a 24-hour period commencing at 08:00 on September 13, 2017, were included. The final follow-up date was November 13, 2017.

EXPOSURES

Infection diagnosis and receipt of antibiotics.

MAIN OUTCOMES AND MEASURES

Prevalence of infection and antibiotic exposure (cross-sectional design) and all-cause in-hospital mortality (longitudinal design).

RESULTS

Among 15 202 included patients (mean age, 61.1 years [SD, 17.3 years]; 9181 were men [60.4%]), infection data were available for 15 165 (99.8%); 8135 (54%) had suspected or proven infection, including 1760 (22%) with ICU-acquired infection. A total of 10 640 patients (70%) received at least 1 antibiotic. The proportion of patients with suspected or proven infection ranged from 43% (141/328) in Australasia to 60% (1892/3150) in Asia and the Middle East. Among the 8135 patients with suspected or proven infection, 5259 (65%) had at least 1 positive microbiological culture; gram-negative microorganisms were identified in 67% of these patients (n = 3540), gram-positive microorganisms in 37% (n = 1946), and fungal microorganisms in 16% (n = 864). The in-hospital mortality rate was 30% (2404/7936) in patients with suspected or proven infection. In a multilevel analysis, ICU-acquired infection was independently associated with higher risk of mortality compared with community-acquired infection (odds ratio [OR], 1.32 [95% CI, 1.10-1.60]; P = .003). Among antibiotic-resistant microorganisms, infection with vancomycin-resistant Enterococcus (OR, 2.41 [95% CI, 1.43-4.06]; P = .001), Klebsiella resistant to β-lactam antibiotics, including third-generation cephalosporins and carbapenems (OR, 1.29 [95% CI, 1.02-1.63]; P = .03), or carbapenem-resistant Acinetobacter species (OR, 1.40 [95% CI, 1.08-1.81]; P = .01) was independently associated with a higher risk of death vs infection with another microorganism.

CONCLUSIONS AND RELEVANCE

In a worldwide sample of patients admitted to ICUs in September 2017, the prevalence of suspected or proven infection was high, with a substantial risk of in-hospital mortality.

Taking the STING Out of Sepsis?

In this issue of Cell Host & Microbe, Zhang et al. use a sepsis mouse model to show that macrophage-specific release of coagulation factor F3 depends on pathogen detection and responses mediated by TMEM173/STING. The therapeutic power of targeting TMEM173/STING-F3 is evident in mice, but will it penetrate the sepsis bedside?

Sepsis-associated pathways segregate cancer groups

BACKGROUND

Sepsis and cancer are both leading causes of death, and occurrence of any one, increases the likelihood of the other. While cancer patients are susceptible to sepsis, survivors of sepsis are also susceptible to develop certain cancers. This mutual dependence for susceptibility suggests shared biology between the two disease categories. Earlier analysis had revealed a cancer-related pathway to be up-regulated in Septic Shock (SS), an advanced stage of sepsis. This has motivated a more comprehensive comparison of the transcriptomes of SS and cancer.

METHODS

Gene Set Enrichment Analysis was performed to detect the pathways enriched in SS and cancer. Thereafter, hierarchical clustering was applied to identify relative segregation of 17 cancer types into two groups vis-a-vis SS. Biological significance of the selected pathways was explored by network analysis. Clinical significance of the pathways was tested by survival analysis. A robust classifier of cancer groups was developed based on machine learning.

RESULTS

A total of 66 pathways were observed to be enriched in both SS and cancer. However, clustering segregated cancer types into two categories based on the direction of transcriptomic change. In general, there was up-regulation in SS and one group of cancer (termed Sepsis-Like Cancer, or SLC), but not in other cancers (termed Cancer Alone, or CA). The SLC group mainly consisted of malignancies of the gastrointestinal tract (head and neck, oesophagus, stomach, liver and biliary system) often associated with infection. Machine learning classifier successfully segregated the two cancer groups with high accuracy (> 98%). Additionally, pathway up-regulation was observed to be associated with survival in the SLC group of cancers.

CONCLUSION

Transcriptome-based systems biology approach segregates cancer into two groups (SLC and CA) based on similarity with SS. Host response to infection plays a key role in pathogenesis of SS and SLC. However, we hypothesize that some component of the host response is protective in both SS and SLC.

Sepsis therapies: learning from 30 years of failure of translational research to propose new leads

Sepsis has been identified by the World Health Organization (WHO) as a global health priority. There has been a tremendous effort to decipher underlying mechanisms responsible for organ failure and death, and to develop new treatments. Despite saving thousands of animals over the last three decades in multiple preclinical studies, no new effective drug has emerged that has clearly improved patient outcomes. In the present review, we analyze the reasons for this failure, focusing on the inclusion of inappropriate patients and the use of irrelevant animal models. We advocate against repeating the same mistakes and propose changes to the research paradigm. We discuss the long-term consequences of surviving sepsis and, finally, list some putative approaches-both old and new-that could help save lives and improve survivorship.

GILZ in sepsis: "Poor is the pupil who does not surpass his master"

With the legendary saying of Leonardo da Vinci in the title, we suggest that Glucocorticoid Induced Leucine Zipper (GILZ) may have more promising effects against polymicrobial sepsis, than glucocorticoids (GC). Indeed, the use of GCs in sepsis remains a matter of debate. The rationale for their use in sepsis is to modulate the exaggerated inflammatory response while maintaining innate immunity. However, GC resistance and side-effects limit their therapeutic value in sepsis. Hence, there is a growing interest in understanding the mechanisms by which GCs modulate immune responses upon infection. In this issue of the European Journal of Immunology, Ellouze et al. provide data demonstrating that deregulated expression of GILZ, a GC-induced protein, in monocytes/macrophages (M/M) recovered from septic shock patients may contribute to the pathogenesis. Furthermore, the authors demonstrate that GILZ overexpression in M/M improves outcome in septic animals by limiting systemic inflammation while increasing bacterial clearance. Overall, these data provide evidence that GCs may modulate immune responses via GILZ and that GILZ is a valuable alternative for GC therapy in sepsis.