Herpes simplex encephalitis in France: incidence, 6-month rehospitalizations and mortality

BACKGROUND

Herpes simplex encephalitis (HSE) is a disease with unfavorable vital and functional prognoses. There are no recent epidemiological data on HSE at a national level using real-life databases, especially in France. This study aimed to report the incidence, the clinical characteristics and outcomes of the patients with HSE.

METHODS

We conducted a comprehensive retrospective cohort study on all patients hospitalized for HSE in France between 2015 and 2022 using national hospital discharge databases. Incidence, socio-demographic and clinical characteristics (including comorbidities, seizure, stays' features, intensive care supports) were described. The short- (first stay) and long-term (6-month) outcomes were reported, in terms of mortality and rehospitalizations.

RESULTS

1425 HSE patients were included (median age 67 [54-77] years old, M/F sex ratio 1.07), giving a mean yearly hospital incidence of 2.3 [2.1-2.5] per 1,000,000 inhabitants. 51.2% of the patients were admitted in ICU (n = 730), of whom 59.0% were mechanically ventilated. The overall mortality during the first stay was 14.3% (n = 204), up to 17.9% for ICU patients. Within 6 months, among the survivors, 10.1% had at least one rehospitalization related to HSE. At 6 months, 16.5% of all patients had died (n = 235), 20.8% for ICU patients.

CONCLUSION

In France, the incidence of hospitalizations for HSE was 2.3 per 1,000,000 inhabitants with more than half of the patients admitted in ICU and a 6-month in-hospital mortality about 16.5%. This real-life update on the characteristics and severe outcomes of the disease raises awareness among care practitioners, of the serious nature of the disease, and thus can lead to higher vigilance.

COVID-19 associated pulmonary aspergillosis in critically-ill patients: a prospective multicenter study in the era of Delta and Omicron variants

BACKGROUND

During the first COVID-19 pandemic wave, COVID-19-associated pulmonary aspergillosis (CAPA) has been reported in up to 11-28% of critically ill COVID-19 patients and associated with increased mortality. As new SARS-CoV-2 variants emerged, the characteristics of critically ill COVID-19 patients have evolved, particularly in the era of Omicron. The purpose of this study is to investigate the characteristics of CAPA in the era of new variants.

METHODS

This is a prospective multicenter observational cohort study conducted in France in 36 participating intensive care units (ICU), between December 7th, 2021 and April 26th 2023. Diagnosis criteria of CAPA relied on European Confederation of Medical Mycology (ECMM)/International Society for Human & Animal Mycology (ISHAM) consensus criteria.

RESULTS

566 patients were included over the study period. The prevalence of CAPA was 5.1% [95% CI 3.4-7.3], and rose to 9.1% among patients who required invasive mechanical ventilation (IMV). Univariable analysis showed that CAPA patients were more frequently immunosuppressed and required more frequently IMV support, vasopressors and renal replacement therapy during ICU stay than non-CAPA patients. SAPS II score at ICU admission, immunosuppression, and a SARS-CoV-2 Delta variant were independently associated with CAPA in multivariable logistic regression analysis. Although CAPA was not significantly associated with day-28 mortality, patients with CAPA experienced a longer duration of mechanical ventilation and ICU stay.

CONCLUSION

This study contributes valuable insights into the prevalence, characteristics, and outcomes of CAPA in the era of Delta and Omicron variants. We report a lower prevalence of CAPA (5.1%) among critically-ill COVID-19 patients than previously reported, mainly affecting intubated-patients. Duration of mechanical ventilation and ICU stay were significantly longer in CAPA patients.

Fluid Intake in Critically Ill Patients: The "Save Useless Fluids For Intensive Resuscitation" Multicenter Prospective Cohort Study

OBJECTIVES

Patients at risk of adverse effects related to positive fluid balance could benefit from fluid intake optimization. Less attention is paid to nonresuscitation fluids. We aim to evaluate the heterogeneity of fluid intake at the initial phase of resuscitation.

DESIGN

Prospective multicenter cohort study.

SETTING

Thirty ICUs across France and one in Spain.

PATIENTS

Patients requiring vasopressors and/or invasive mechanical ventilation.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

All fluids administered by vascular or enteral lines were recorded over 24 hours following admission and were classified in four main groups according to their predefined indication: fluids having a well-documented homeostasis goal (resuscitation fluids, rehydration, blood products, and nutrition), drug carriers, maintenance fluids, and fluids for technical needs. Models of regression were constructed to determine fluid intake predicted by patient characteristics. Centers were classified according to tertiles of fluid intake. The cohort included 296 patients. The median total volume of fluids was 3546 mL (interquartile range, 2441-4955 mL), with fluids indisputably required for body fluid homeostasis representing 36% of this total. Saline, glucose-containing high chloride crystalloids, and balanced crystalloids represented 43%, 27%, and 16% of total volume, respectively. Whatever the class of fluids, center of inclusion was the strongest factor associated with volumes. Compared with the first tertile, the difference between the volume predicted by patient characteristics and the volume given was +1.2 ± 2.0 L in tertile 2 and +3.0 ± 2.8 L in tertile 3.

CONCLUSIONS

Fluids indisputably required for body fluid homeostasis represent the minority of fluid intake during the 24 hours after ICU admission. Center effect is the strongest factor associated with the volume of fluids. Heterogeneity in practices suggests that optimal strategies for volume and goals of common fluids administration need to be developed.

The proteolytic airway environment associated with pneumonia acts as a barrier for treatment with anti-infective antibodies

Like pneumonia, coronavirus disease 2019 (COVID-19) is characterized by a massive infiltration of innate immune cells (such as polymorphonuclear leukocytes) into the airways and alveolar spaces. These cells release proteases that may degrade therapeutic antibodies and thus limit their effectiveness. Here, we investigated the in vitro and ex vivo impact on anti-severe acute respiratory syndrome coronavirus 2 (SARS-CoV2) IgG1s and other IgG subclasses (IgG2 and IgG4) of the neutrophil elastase, proteinase 3 and cathepsin G (the three main neutrophil serine proteases) found in endotracheal aspirates from patients with severe COVID-19. Although the IgGs were sensitive to neutrophil serine proteases, IgG2 was most resistant to proteolytic degradation. The two anti-SARS CoV2 antibodies (casirivimab and imdevimab) were sensitive to the lung's proteolytic environment, although neutrophil serine protease inhibitors only partly limited the degradation. Overall, our results show that the pneumonia-associated imbalance between proteases and their inhibitors in the airways contributes to degradation of antiviral antibodies.

Invasive group A streptococcal infections requiring admission to ICU: a nationwide, multicenter, retrospective study (ISTRE study)

BACKGROUND

Group A Streptococcus is responsible for severe and potentially lethal invasive conditions requiring intensive care unit (ICU) admission, such as streptococcal toxic shock-like syndrome (STSS). A rebound of invasive group A streptococcal (iGAS) infection after COVID-19-associated barrier measures has been observed in children. Several intensivists of French adult ICUs have reported similar bedside impressions without objective data. We aimed to compare the incidence of iGAS infection before and after the COVID-19 pandemic, describe iGAS patients' characteristics, and determine ICU mortality associated factors.

METHODS

We performed a retrospective multicenter cohort study in 37 French ICUs, including all patients admitted for iGAS infections for two periods: two years before period (October 2018 to March 2019 and October 2019 to March 2020) and a one-year after period (October 2022 to March 2023) COVID-19 pandemic. iGAS infection was defined by Group A Streptococcus isolation from a normally sterile site. iGAS infections were identified using the International Classification of Diseases and confirmed with each center's microbiology laboratory databases. The incidence of iGAS infections was expressed in case rate.

RESULTS

Two hundred and twenty-two patients were admitted to ICU for iGAS infections: 73 before and 149 after COVID-19 pandemic. Their case rate during the period before and after COVID-19 pandemic was 205 and 949/100,000 ICU admissions, respectively (p < 0.001), with more frequent STSS after the COVID-19 pandemic (61% vs. 45%, p = 0.015). iGAS patients (n = 222) had a median SOFA score of 8 (5-13), invasive mechanical ventilation and norepinephrine in 61% and 74% of patients. ICU mortality in iGAS patients was 19% (14% before and 22% after COVID-19 pandemic; p = 0.135). In multivariate analysis, invasive mechanical ventilation (OR = 6.08 (1.71-21.60), p = 0.005), STSS (OR = 5.75 (1.71-19.22), p = 0.005), acute kidney injury (OR = 4.85 (1.05-22.42), p = 0.043), immunosuppression (OR = 4.02 (1.03-15.59), p = 0.044), and diabetes (OR = 3.92 (1.42-10.79), p = 0.008) were significantly associated with ICU mortality.

CONCLUSION

The incidence of iGAS infections requiring ICU admission increased by 4 to 5 after the COVID-19 pandemic. After the COVID-19 pandemic, the rate of STSS was higher, with no significant increase in ICU mortality rate.

Long-term immunosuppressive treatment is not associated with worse outcome in patients hospitalized in the intensive care unit for septic shock: the PACIFIC study

BACKGROUND

Except in a few retrospective studies mainly including patients under chemotherapy, information regarding the impact of immunosuppressive therapy on the prognosis of patients admitted to the intensive care unit (ICU) for septic shock is scarce. Accordingly, the PACIFIC study aimed to asses if immunosuppressive therapy is associated with an increased mortality in patients admitted to the ICU for septic shock.

METHODS

This was a retrospective epidemiological multicentre study. Eight high enroller centres in septic shock randomised controlled trials (RCTs) participated in the study. Patients in the "exposed" group were selected from the screen failure logs of seven recent RCTs and excluded because of immunosuppressive treatment. The "non-exposed" patients were those included in the placebo arm of the same RCTs. A multivariate logistic regression model was used to estimate the risk of death.

RESULTS

Among the 433 patients enrolled, 103 were included in the "exposed" group and 330 in the "non-exposed" group. Reason for immunosuppressive therapy included organ transplantation (n = 45 [44%]) or systemic disease (n = 58 [56%]). ICU mortality rate was 24% in the "exposed" group and 25% in the "non-exposed" group (p = 0.9). Neither in univariate nor in multivariate analysis immunosuppressive therapy was associated with a higher ICU mortality (OR: 0.95; [95% CI 0.56-1.58]: p =  0.86 and 1.13 [95% CI 0.61-2.05]: p =  0.69, respectively) or 3-month mortality (OR: 1.13; [95% CI 0.69-1.82]: p =  0.62 and OR: 1.36 [95% CI 0.78-2.37]: p =  0.28, respectively).

CONCLUSIONS

In this study, long-term immunosuppressive therapy excluding chemotherapy was not associated with significantly higher or lower ICU and 3-month mortality in patients admitted to the ICU for septic shock.

Outcomes in COVID-19 Patients With Acute Encephalopathy and Coma: An International Prospective Study

OBJECTIVE

To report the prevalence of acute encephalopathy and outcomes in patients with severe COVID-19, and to identify determinants of 90-day outcomes.

METHODS

Data from adults with severe COVID-19 and acute encephalopathy were prospectively collected for patients requiring intensive care unit management in 31 university or university-affiliated in six countries (France, USA, Colombia, Spain, Mexico, Brazil) between March and September of 2020. Acute encephalopathy was defined, as recently recommended, as subsyndromal delirium or delirium, or as a comatose state in case of severely decreased level of consciousness. Logistic multivariable regression was performed to identify factors associated with 90-day outcomes. A Glasgow Outcome Scale-Extended score (GOS-E) of 1-4 was considered a poor outcome (indicating death, vegetative state, or severe disability).

RESULTS

Of 4060 patients admitted with COVID-19, 374 (9.2%) experienced acute encephalopathy at or prior to the ICU admission. A total of 199/345 (57.7%) patients had a poor outcome at 90-day follow-up as evaluated by the GOS-E (29 patients were lost to follow-up). On multivariable analysis, age >70 years (odds ratio [OR] 4.01, 95% confidence interval [CI], 2.25-7.15), presumed fatal comorbidity (3.98, 1.68-9.44), Glasgow Coma Scale score <9 before/at ICU admission ICU admission (2.20, 1.22-3.98), vasopressor/inotrope support during ICU stay (3.91, 1.97-7.76), renal replacement therapy during ICU stay (2.31, 1.21-4.50), and CNS ischemic or hemorrhagic complications as acute encephalopathy etiology (3.22, 1.41-7.82) were independently associated with higher odds of poor 90-day outcome. Status epilepticus, posterior reversible encephalopathy syndrome, and reversible cerebral vasoconstriction syndrome were associated with lower odds of poor 90-day outcome (OR 0.15, 95% CI 0.03-0.83).

CONCLUSIONS

and Relevance: In this observational study, we found a low prevalence of acute encephalopathy at ICU admission in COVID-19 patients. Over a half of patients with COVID-19 presenting with acute encephalopathy had poor outcomes as evaluated by GOS-E. Determinants of poor 90-day outcome were dominated by older age, comorbidities, degree of impairment of consciousness before/at ICU admission, association with other organ failures, and acute encephalopathy etiology.

TRIAL REGISTRATION

The study is registered with ClinicalTrials.gov, number NCT04320472.

Could treatment with immunomodulatory agents targeting IL-1, IL-6, or JAK signalling improve outcomes in patients with severe influenza pneumonia? A systematic and narrative review

Background: Influenza is a global cause of morbidity and mortality and a significant risk for a future pandemic infection. Host hyperinflammation, similar to that seen in COVID-19, may occur in response to influenza virus pneumonia, with Janus kinase (JAK) signalling and proinflammatory cytokines Interleukin (IL)-1 and IL-6 involved. Immune modulation treatment of hospitalised and critically ill COVID-19 patients, including with IL-6 and JAK inhibitors, has been found to be beneficial. Significant interest exists in the use of immunomodulatory agents targeting these pathways in the treatment of severe influenza pneumonia. Methods: We conducted a review with both systematic and narrative methods to assess whether, in patients with severe influenza pneumonia, treatment with immunomodulatory agents targeting IL-1, IL-6 or JAK signalling, in comparison to no immune modulation, is beneficial and improves clinical outcomes. Results: Our systematic search screened 5409 records and found no randomised controlled trials of IL-1, IL-6 or JAK immunomodulatory agents in patients with severe influenza pneumonia. To support this systematic search, we provide a narrative review of the biological rationale, previous use of these agents, including in hospitalised patients with COVID-19, and an overview of their safety profiles. Conclusions: Although immune modulation has proven successful in treating hospitalised and critically ill patients with COVID-19 and a biological rationale exists for testing these agents in influenza, no agents targeting IL-1, IL-6 or JAK signalling have been assessed in randomised controlled trials of patients with severe influenza pneumonia. This highlights a significant evidence gap.

Host succinate inhibits influenza virus infection through succinylation and nuclear retention of the viral nucleoprotein

Influenza virus infection causes considerable morbidity and mortality, but current therapies have limited efficacy. We hypothesized that investigating the metabolic signaling during infection may help to design innovative antiviral approaches. Using bronchoalveolar lavages of infected mice, we here demonstrate that influenza virus induces a major reprogramming of lung metabolism. We focused on mitochondria‐derived succinate that accumulated both in the respiratory fluids of virus‐challenged mice and of patients with influenza pneumonia. Notably, succinate displays a potent antiviral activity in vitro as it inhibits the multiplication of influenza A/H1N1 and A/H3N2 strains and strongly decreases virus‐triggered metabolic perturbations and inflammatory responses. Moreover, mice receiving succinate intranasally showed reduced viral loads in lungs and increased survival compared to control animals. The antiviral mechanism involves a succinate‐dependent posttranslational modification, that is, succinylation, of the viral nucleoprotein at the highly conserved K87 residue. Succinylation of viral nucleoprotein altered its electrostatic interactions with viral RNA and further impaired the trafficking of viral ribonucleoprotein complexes. The finding that succinate efficiently disrupts the influenza replication cycle opens up new avenues for improved treatment of influenza pneumonia.

Recruitment and training of alveolar macrophages after pneumococcal pneumonia

Recovery from pneumococcal pneumonia remodels the pool of alveolar macrophages so that they exhibit new surface marker profiles, transcriptomes, metabolomes, and responses to infection. Mechanisms mediating alveolar macrophage phenotypes after pneumococcal pneumonia have not been delineated. IFN-γ and its receptor on alveolar macrophages were essential for certain, but not all, aspects of the remodeled alveolar macrophage phenotype. IFN-γ was produced by CD4⁺ T cells plus other cells, and CD4⁺ cell depletion did not prevent alveolar macrophage remodeling. In mice infected or recovering from pneumococcus, monocytes were recruited to the lungs, and the monocyte-derived macrophages developed characteristics of alveolar macrophages. CCR2 mediated the early monocyte recruitment but was not essential to the development of the remodeled alveolar macrophage phenotype. Lineage tracing demonstrated that recovery from pneumococcal pneumonias converted the pool of alveolar macrophages from being primarily of embryonic origin to being primarily of adult hematopoietic stem cell origin. Alveolar macrophages of either origin demonstrated similar remodeled phenotypes, suggesting that ontogeny did not dictate phenotype. Our data reveal that the remodeled alveolar macrophage phenotype in lungs recovered from pneumococcal pneumonia results from a combination of new recruitment plus training of both the original cells and the new recruits.

Kallikrein-related peptidase 5 contributes to the remodeling and repair of bronchial epithelium

Inflammation, oxidative stress, and protease/protease inhibitor imbalance with excessive production of proteases are factors associated with pathogenesis of the chronic obstructive pulmonary disease (COPD). In this study, we report that kallikrein-related peptidase 5 (KLK5) is a crucial protease involved in extracellular matrix (ECM) remodeling and bronchial epithelial repair after injury. First, we showed that KLK5 degrades the basal layer formed by culture of primary bronchial epithelial cells from COPD or non-COPD patients. Also, exogenous KLK5 acted differently on BEAS-2B cells already engaged in epithelial-to-mesenchymal transition (EMT) or on 16HBE 14o- cells harboring epithelial characteristics. Indeed, by inducing EMT, KLK5 reduced BEAS-2B cell adherence to the ECM. This effect, neutralized by tissue factor pathway inhibitor 2, a kunitz-type serine protease inhibitor, was due to a direct proteolytic activity of KLK5 on E-cadherin, β-catenin, fibronectin, and α5β1 integrin. Thus, KLK5 may strengthen EMT mechanisms and promote the migration of cells by activating the mitogen-activated protein kinase signaling pathway required for this function. In contrast, knockdown of endogenous KLK5 in 16HBE14o- cells, accelerated wound healing repair after injury, and exogenous KLK5 addition delayed the closure repair. These data suggest that among proteases, KLK5 could play a critical role in airway remodeling events associated with COPD during exposure of the pulmonary epithelium to inhaled irritants or smoking and the inflammation process.

TLR5 signalling is hyper-responsive in porcine cystic fibrosis airways epithelium

Excessive lung inflammation and airway epithelium damage are hallmarks of cystic fibrosis (CF) disease. It is unclear whether lung inflammation is related to an intrinsic defect in the immune response or to chronic infection. We aimed to determine whether TLR5-mediated response is defective in the CF airway epithelium. We used a newborn CF pig model to study intrinsic alterations in CF airway epithelium innate immune response. Airway epithelial cells (AECs) were stimulated with flagellin or lipopolysaccharide to determine responses specific for TLR5 and TLR4, respectively. We observed a significant increase in cytokine secretion when CF AECs were stimulated with flagellin compared to wild type (WT) AECs. These results were recapitulated when AECs were treated with an inhibitor of CFTR channel activity. We show that TLR5-signalling is altered in CF lung epithelium at birth. Modulation of TLR5 signalling could contribute to better control the excessive inflammatory response observed in CF lungs.

Case fatality inequalities of critically ill COVID-19 patients according to patient-, hospital- and region-related factors: a French nationwide study

Background

The COVID-19 sanitary crisis inflicted different challenges regarding the reorganization of the human and logistic resources, particularly in intensive care unit (ICU). Interdependence between regional pandemic burden and individual outcome remains unknown. The study aimed to assess the association between ICU bed occupancy and case fatality rate of critically ill COVID-19 patients.

Methods

A cross-sectional study was performed in France, using the national hospital discharge database from March to May, 2020. All patients admitted to ICU for COVID-19 were included. Case fatality was described according to: (i) patient’s characteristics (age, sex, comorbid conditions, ICU interventions); (ii) hospital’s characteristics (baseline ICU experience assessed by the number of ICU stays in 2019, number of ICU physicians per bed), and (iii) the regional outbreak-related profiles (workload indicator based on ICU bed occupancy). The determinants of lethal outcome were identified using a logistic regression model.

Results

14,513 COVID-19 patients were admitted to ICU; 4256 died (29.3%), with important regional inequalities in case fatality (from 17.6 to 33.5%). Older age, multimorbidity and clinical severity were associated with higher mortality, as well as a lower baseline ICU experience of the health structure. Regions with more than 10 days with ≥ 75% of ICU occupancy by COVID-19 patients experienced an excess of mortality (up to adjusted OR = 2.2 [1.9–2.6] for region with the highest occupancy rate of ICU beds).

Conclusions

The regions with the highest burden of care in ICU were associated with up to 2.2-fold increase of death rate.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13613-021-00915-4.

Inhaled bacteriophage therapy in a porcine model of pneumonia caused by Pseudomonas aeruginosa during mechanical ventilation

BACKGROUND AND PURPOSE 255: Pseudomonas aeruginosa is a main cause of ventilator-associated pneumonia (VAP) with drug-resistant bacteria. Bacteriophage therapy has experienced resurgence to compensate for the limited development of novel antibiotics. However, phage therapy is limited to a compassionate use so far, resulting from lack of adequate studies in relevant pharmacological models. We used a pig model of pneumonia caused by P. aeruginosa that recapitulates essential features of human disease to study the antimicrobial efficacy of nebulized-phage therapy.

EXPERIMENTAL APPROACH

(i) Lysis kinetic assays were performed to evaluate in vitro phage antibacterial efficacy against P. aeruginosa and select relevant combinations of lytic phages. (ii) The efficacy of the phage combinations was investigated in vivo (murine model of P. aeruginosa lung infection). (iii) We determined the optimal conditions to ensure efficient phage delivery by aerosol during mechanical ventilation. (iv) Lung antimicrobial efficacy of inhaled-phage therapy was evaluated in pigs, which were anaesthetized, mechanically ventilated and infected with P. aeruginosa.

KEY RESULTS

By selecting an active phage cocktail and optimizing aerosol delivery conditions, we were able to deliver high phage concentrations in the lungs, which resulted in a rapid and marked reduction in P. aeruginosa density (1.5-log reduction, p < .001). No infective phage was detected in the sera and urines throughout the experiment.

CONCLUSION AND IMPLICATIONS

Our findings demonstrated (i) the feasibility of delivering large amounts of active phages by nebulization during mechanical ventilation and (ii) rapid control of in situ infection by inhaled bacteriophage in an experimental model of P. aeruginosa pneumonia with high translational value.

Fatal Measles Inclusion-Body Encephalitis in Adult with Untreated AIDS, France

We report a fatal case of measles inclusion-body encephalitis occurring in a woman from Romania with AIDS. After an extensive but unsuccessful diagnostic evaluation, a pan-pathogen shotgun metagenomic approach revealed a measles virus infection. We identified no mutations previously associated with neurovirulence.

Airway Administration of Flagellin Regulates the Inflammatory Response to Pseudomonas aeruginosa

Excessive lung inflammation and airway epithelial damage are hallmarks of human inflammatory lung diseases, such as cystic fibrosis (CF). Enhancement of innate immunity provides protection against pathogens while reducing lung-damaging inflammation. However, the mechanisms underlying innate immunity–mediated protection in the lung remain mysterious, in part because of the lack of appropriate animal models for these human diseases. TLR5 (Toll-like receptor 5) stimulation by its specific ligand, the bacterial protein flagellin, has been proposed to enhance protection against several respiratory infectious diseases, although other cellular events, such as calcium signaling, may also control the intensity of the innate immune response. Here, we investigated the molecular events prompted by stimulation with flagellin and its role in regulating innate immunity in the lung of the pig, which is anatomically and genetically more similar to humans than rodent models. We found that flagellin treatment modulated NF-κB signaling and intracellular calcium homeostasis in airway epithelial cells. Flagellin pretreatment reduced the NF-κB nuclear translocation and the expression of proinflammatory cytokines to a second flagellin stimulus as well as to Pseudomonas aeruginosa infection. Moreover, in vivo administration of flagellin decreased the severity of P. aeruginosa–induced pneumonia. Then we confirmed these beneficial effects of flagellin in a pathological model of CF by using ex vivo precision-cut lung slices from a CF pigz model. These results provide evidence that flagellin treatment contributes to a better regulation of the inflammatory response in inflammatory lung diseases such as CF.

Lung-resident memory B cells protect against bacterial pneumonia

Lung-resident memory B cells (BRM cells) are elicited after influenza infections of mice, but connections to other pathogens and hosts - as well as their functional significance - have yet to be determined. We postulate that BRM cells are core components of lung immunity. To test this, we examined whether lung BRM cells are elicited by the respiratory pathogen pneumococcus, are present in humans, and are important in pneumonia defense. Lungs of mice that had recovered from pneumococcal infections did not contain organized tertiary lymphoid organs, but did have plasma cells and noncirculating memory B cells. The latter expressed distinctive surface markers (including CD69, PD-L2, CD80, and CD73) and were poised to secrete antibodies upon stimulation. Human lungs also contained B cells with a resident memory phenotype. In mice recovered from pneumococcal pneumonia, depletion of PD-L2+ B cells, including lung BRM cells, diminished bacterial clearance and the level of pneumococcus-reactive antibodies in the lung. These data define lung BRM cells as a common feature of pathogen-experienced lungs and provide direct evidence of a role for these cells in pulmonary antibacterial immunity.

Proteinase release from activated neutrophils in mechanically ventilated patients with non-COVID-19 and COVID-19 pneumonia

Severe cases of pneumonia are frequently associated with acute respiratory distress syndrome (ARDS), which carries a mortality rate of about 40% [1]. Uncontrolled host inflammatory response in the lung is a key factor in the transition from pneumonia to ARDS, with alveolocapillary membrane disruption leading to interstitial and alveolar oedema [2]. Neutrophils are part of the innate immune system and are the first responders to local tissue damage and infection. Recruited neutrophils are considered important actors in lung tissue injury [3]. Indeed, their broad arsenal of antimicrobial weaponry can cause direct and indirect collateral damage. Neutrophil serine proteinases (NSPs), including elastase (NE), proteinase 3 (PR3) and cathepsin G (CatG), are released from activated cells and play a part in ARDS pathophysiology, as illustrated in both preclinical and clinical studies [4]. Thus, NSPs emerge as an untapped point for therapeutic interventions in pneumonia-induced ARDS [4]. These NSPs are readily synthesised in neutrophil precursors within the bone marrow and are converted into their active form by cathepsin C (CatC) [5]. They are stored together in cytoplasmic granules and secreted into the extracellular compartment upon stimulation [6].

COVID-19 ARDS is associated with release of biologically active neutrophil elastase-related proteinases to the airways and blood at a comparable level to non-COVID ARDShttps://bit.ly/3nihveh

[Metabokines reviewed: Essential mediators of anti-infectious immunity]

Metabolism and immunity have long been classified in distinct research fields; however, the concept of immunometabolism has recently highlighted their close relationship. Immune cells in an infectious context undergo a metabolic reprogramming that leads to the accumulation of metabolites. Some of these metabolites, called metabokines, play a crucial role in anti-infectious immunity by having immunoregulatory and antimicrobial defence properties. On the one hand, metabokines regulate the response of host immune cells by modulating intracellular signalling and/or inducing post-translational modifications of proteins. On the other hand, metabokines can directly or indirectly target pathogens by inhibiting microbial metabolic pathways, restoring the sensitivity of bacteria to antibiotics, and disrupting viral replication cycles. These discoveries on metabokine properties could pave the way for the development of innovative anti-infectious metabolic treatments.

Ozonation of 47 organic micropollutants in secondary treated municipal effluents: Direct and indirect kinetic reaction rates and modelling

Micropollutants like pharmaceuticals, hormones and pesticides are still found in treated municipal wastewater. An effective way to degrade micropollutants is to use oxidants such as ozone or hydroxyl radicals. We designed an innovative experimental protocol combining batch experiments and a study of a full-scale WWTP to understand and predict the removal via ozonation of typical micropollutants present in secondary treated effluents. First, the direct and indirect ozonation of 47 organic micropollutants was scrutinized, then a model was developed and calibrated to simulate the ozone transfers and the oxidation of the selected micropollutants. The kinetic rate constants between micropollutants and ozone or hydroxyl radicals (OH^●) were determined for 47 micropollutants found in secondary treated effluent. We classified the micropollutants into low- (k_O3 between 1.50 and 4.47 × 10² L mol^-1. s^-1), medium- (k_O3 between 1.31 × 10³ and 4.92 × 10³ L mol^-1. s^-1) and high-oxidizable groups (k_O3 between 9.44 × 10⁴ and 8.18 × 10⁶ L mol^-1. s^-1) according to their reactivity with ozone, and identified the major degradation pathways for all 47 micropollutants. Micropolluants of the low- and medium-oxidizable groups were largely eliminated by the indirect pathway, at 96% and 84% on average, respectively. In contrast, micropollutants of high-oxidizable group were largely eliminated by the direct pathway, at 98% on average. The model successfully simulated the direct and indirect ozonation of the 47 micropollutants in batch experiments and confirmed the predominant pathways for each group. Finally, the model was applied to the full-scale ozonation process operated at an ozone dose ranging from 0.5 to 1.6 gO₃. gDOC^-1. The model was found to reliably simulate the ozonation-process removal efficiencies for 4 micropollutants (imidacloprid, fenofibric acid, metronidazole and ketoprofen).

2-year survival among elderly hospitalised for acute respiratory infection versus hip fracture: a useful comparison to raise awareness

We read with great interest the article by Cillónizet al. [1]. The authors nicely reported and discussed recent literature showing that pneumonia is a common lung infection that can be life-threatening, with particular concern for the elderly. Indeed, the annual incidences of hospitalisation for respiratory infections increase with age from 0.2% (for patients aged <75 years) to 1.9% (for age 80–84 years), 3.2% (for age 85–89 years) and 5.0% (for age ≥90 years) [2]. For the elderly, pneumonia has the greatest risk of death among the common causes of hospitalisation [3]. We do agree with the authors when they concluded that preventive interventions are of pivotal importance to improve outcomes and reduce the occurrence of adverse consequences [1]. However, we would like to emphasise that there is a mismatch between the high morbidity and mortality caused by respiratory infection and the low public awareness of this disease. A large pneumonia awareness survey involving over 9000 adults aged ≥50 years highlighted that most fail to accurately gauge their own pneumonia risk, leading to inadequate pneumonia prevention efforts including low uptake of existing vaccines [4]. The low public awareness of respiratory infection risk and severity in the elderly is a barrier to healthcare delivery and a driver of unhealthy ageing [5]. It is critical to raise awareness of this disease among the general public to improve the management of this largely preventable infectious disease [5].

If breaking a hip feels like a concern for the elderly, then getting pneumonia should be twice as concerning: patients hospitalised for lung infection had 3.3-fold greater in-hospital mortality and 1.8-fold increased risk of death at 2 yearshttps://bit.ly/2Xqsrf6

Correlation and clinical relevance of animal models for inhaled pharmaceuticals and biopharmaceuticals

Nonclinical studies are fundamental for the development of inhaled drugs, as for any drug product, and for successful translation to clinical practice. They include in silico, in vitro, ex vivo and in vivo studies and are intended to provide a comprehensive understanding of the inhaled drug beneficial and detrimental effects. To date, animal models cannot be circumvented during drug development programs, acting as surrogates of humans to predict inhaled drug response, fate and toxicity. Herein, we review the animal models used during the different development stages of inhaled pharmaceuticals and biopharmaceuticals, highlighting their strengths and limitations.

Controlled Heat and Humidity-Based Treatment for the Reuse of Personal Protective Equipment: A Pragmatic Proof-of-Concept to Address the Mass Shortage of Surgical Masks and N95/FFP2 Respirators and to Prevent the SARS-CoV2 Transmission

Background: The coronavirus infectious disease-2019 (COVID-19) pandemic has led to an unprecedented shortage of healthcare resources, primarily personal protective equipment like surgical masks, and N95/filtering face piece type 2 (FFP2) respirators.

Objective: Reuse of surgical masks and N95/FFP2 respirators may circumvent the supply chain constraints and thus overcome mass shortage. Methods, design, setting, and measurement: Herein, we tested the effects of dry- and moist-air controlled heating treatment on structure and chemical integrity, decontamination yield, and filtration performance of surgical masks and FFP2 respirators.

Results: We found that treatment in a climate chamber at 70°C during 1 h with 75% humidity rate was adequate for enabling substantial decontamination of both respiratory viruses, oropharyngeal bacteria, and model animal coronaviuses, while maintaining a satisfying filtering capacity.

Limitations: Further studies are now required to confirm the feasibility of the whole process during routine practice.

Conclusion: Our findings provide compelling evidence for the recycling of pre-used surgical masks and N95/FFP2 respirators in case of imminent mass shortfall.

Effect of Hydrocortisone on 21-Day Mortality or Respiratory Support Among Critically Ill Patients With COVID-19: A Randomized Clinical Trial

Importance

Coronavirus disease 2019 (COVID-19) is associated with severe lung damage. Corticosteroids are a possible therapeutic option.

Objective

To determine the effect of hydrocortisone on treatment failure on day 21 in critically ill patients with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and acute respiratory failure.

Design, Setting, and Participants

Multicenter randomized double-blind sequential trial conducted in France, with interim analyses planned every 50 patients. Patients admitted to the intensive care unit (ICU) for COVID-19-related acute respiratory failure were enrolled from March 7 to June 1, 2020, with last follow-up on June 29, 2020. The study intended to enroll 290 patients but was stopped early following the recommendation of the data and safety monitoring board.

Interventions

Patients were randomized to receive low-dose hydrocortisone (n = 76) or placebo (n = 73).

Main Outcomes and Measures

The primary outcome, treatment failure on day 21, was defined as death or persistent dependency on mechanical ventilation or high-flow oxygen therapy. Prespecified secondary outcomes included the need for tracheal intubation (among patients not intubated at baseline); cumulative incidences (until day 21) of prone position sessions, extracorporeal membrane oxygenation, and inhaled nitric oxide; Pao2:Fio2 ratio measured daily from day 1 to day 7, then on days 14 and 21; and the proportion of patients with secondary infections during their ICU stay.

Results

The study was stopped after 149 patients (mean age, 62.2 years; 30.2% women; 81.2% mechanically ventilated) were enrolled. One hundred forty-eight patients (99.3%) completed the study, and there were 69 treatment failure events, including 11 deaths in the hydrocortisone group and 20 deaths in the placebo group. The primary outcome, treatment failure on day 21, occurred in 32 of 76 patients (42.1%) in the hydrocortisone group compared with 37 of 73 (50.7%) in the placebo group (difference of proportions, -8.6% [95.48% CI, -24.9% to 7.7%]; P = .29). Of the 4 prespecified secondary outcomes, none showed a significant difference. No serious adverse events were related to the study treatment.

Conclusions and Relevance

In this study of critically ill patients with COVID-19 and acute respiratory failure, low-dose hydrocortisone, compared with placebo, did not significantly reduce treatment failure (defined as death or persistent respiratory support) at day 21. However, the study was stopped early and likely was underpowered to find a statistically and clinically important difference in the primary outcome.

Trial Registration

ClinicalTrials.gov Identifier: NCT02517489.

Phenotypical and functional alteration of unconventional T cells in severe COVID-19 patients

COVID-19 includes lung infection ranging from mild pneumonia to life-threatening acute respiratory distress syndrome (ARDS). Dysregulated host immune response in the lung is a key feature in ARDS pathophysiology. However, cellular actors involved in COVID-19-driven ARDS are poorly understood. Here, in blood and airways of severe COVID-19 patients, we serially analyzed unconventional T cells, a heterogeneous class of T lymphocytes (MAIT, γδT, and iNKT cells) with potent antimicrobial and regulatory functions. Circulating unconventional T cells of COVID-19 patients presented with a profound and persistent phenotypic alteration. In the airways, highly activated unconventional T cells were detected, suggesting a potential contribution in the regulation of local inflammation. Finally, expression of the CD69 activation marker on blood iNKT and MAIT cells of COVID-19 patients on admission was predictive of clinical course and disease severity. Thus, COVID-19 patients present with an altered unconventional T cell biology, and further investigations will be required to precisely assess their functions during SARS-CoV-2-driven ARDS.

Clinical performance of four immunoassays for antibodies to SARS-CoV-2, including a prospective analysis for the diagnosis of COVID-19 in a real-life routine care setting

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The sensitivity of evaluated SARS-CoV-2 immunoassays ranged from 95.6% to 97.8%.

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The specificity was 92.1% for Euroimmun IgG and ≥ 98.9% for Abbott IgG, Wantai Ab and DiaPro confirmation IgG assays.

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A lack of specificity was observed for low positive Euroimmun IgG results (ratio<5) and inconclusive RT-PCR results.

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A lack of sensitivity was observed for early serology (<14 days) or late RT-PCR testing (>30 days).

Objectives

The aim of the present study was to evaluate the clinical performance of four SARS-CoV-2 immunoassays and their contribution in routine care for the diagnosis of COVID-19, in order to benefit of robust data before their extensive use.

Methods

The clinical performance of Euroimmun ELISA SARS-CoV-2 IgG, Abbott SARS-CoV-2 IgG, Wantai SARS-CoV-2 Ab ELISA, and DiaPro COVID-19 IgG confirmation were evaluated in the context of both a retrospective and a prospective analysis of COVID-19 patients. The retrospective analysis included plasma samples from 63 COVID-19 patients and 89 control (pre-pandemic) patients. The prospective study included 203 patients who tested either negative (n = 181) or positive (n = 22) by RT-PCR before serology sampling.

Results

The specificity was 92.1 %, 98.9 %, 100 % and 98.9 % and the sensitivity 14 days after onset of symptoms was 95.6 %, 95.6 %, 97.8 % and 95.6 % for Euroimmun IgG, Abbott IgG, Wantai Ab, and DiaPro IgG confirmation SARS-CoV-2 immunoassays, respectively. The low specificity of Euroimmun IgG (for ratio <5) was not confirmed in routine care setting (98.5 % negative agreement). Serology was complementary to RT-PCR in routine care and lead to identification of false positive (Ct>38, <2 targets detected) and false negative RT-PCR results (>1 month post onset of symptoms).

Conclusions

Serology was complementary to RT-PCR for the diagnosis of COVID-19 at least 14 days after onset of symptoms. First line serology testing can be performed with Wantai Ab or Abbott IgG assays, while DiaPro IgG confirmation assay can be used as an efficient confirmation assay.

Techniques de détection des protéines

La détection de protéines au sein de tissus/fl uides estaujourd’hui de pratique courante (ex : western blot oucytométrie en fl ux) et utilisée dans des domaines trèsdifférents, par exemple pour confi rmer une sérologieVIH positive ou réaliser un dosage toxicologique. Dansle domaine de la recherche, ces techniques sont également couramment utilisées notamment pour développerdes biomarqueurs d’intérêt diagnostic ou pronostic.L’objectif de cette fi che est de présenter les différentestechniques utilisées de façon courante pour la détectiondes protéines. La cytométrie en fl ux a fait l’objet d’uneprécédente publication. Quelle que soit la techniqueprésentée, la présence d’un contrôle positif et d’un contrôlenégatif est indispensable à l’interprétation des résultats

Long-term survival of elderly patients after intensive care unit admission for acute respiratory infection: a population-based, propensity score-matched cohort study

Background

Intensive care unit (ICU) hospitalisations of elderly patients with acute respiratory infection have increased, yet the long-term effects of ICU admission among elderly individuals remain unknown. We examined differences over the 2 years after discharge in mortality, healthcare utilisation and frailty score between elderly survivors of ARI in the ICU and an elderly control population.

Methods

We used 2009–2017 data from 39 hospital discharge databases. Patients ≥ 80 years old discharged alive from ICU hospitalisation for acute respiratory infection were propensity score-matched with controls (cataract surgery) discharged from the hospital at the same time and adjusted for age, sex and comorbidities present before hospitalisation. We reported 2-year mortality and compared healthcare utilisation and frailty scores in the 2-year periods before and after ICU hospitalisation.

Results

One thousand two hundred and twenty elderly survivors of acute respiratory infection in the ICU were discharged, and 988 were successfully matched with controls. After discharge, patients had a 10.1-fold [95% CI, 6.1–17.3] higher risk of death at 6 months and 3.6-fold [95% CI, 2.9–4.6] higher risk of death at 2 years compared with controls. They also had a 2-fold increase in both healthcare utilisation and frailty score in the 2 years after hospital discharge, whereas healthcare utilisation and frailty scores among controls were stable before and after hospitalisation.

Conclusions

We observed a substantially increased rate of death in the years following ICU hospitalisation for elderly patients along with elevated healthcare resource use and accelerated age-associated decline as assessed by frailty score. These findings provide data for better informed goals-of-care discussions and may help target post-ICU discharge services.

Intrinsic alterations in peripheral neutrophils from cystic fibrosis newborn piglets

BACKGROUND

The hallmark of the cystic fibrosis (CF) lung disease is a neutrophil dominated lung environment that is associated to chronic lung tissue destruction and ultimately the patient's death. It is unclear whether the exacerbated neutrophil response is primary related to a defective CFTR or rather secondary to chronic bacterial colonization and inflammation. Here, we hypothesized that CF peripheral blood neutrophils present intrinsic alteration at birth before the start of an inflammatory process.

METHODS

Peripheral blood neutrophils were isolated from newborn CFTR^+/+ and CFTR^-/- piglets. Neutrophils immunophenotype was evaluated by flow cytometry. Lipidomic and proteomic profile were characterized by liquid chromatography/tandem mass spectrometry (LC-MS/MS), intact cell matrix-assisted laser desorption/ionization mass spectrometry (ICM-MS) followed by top-down high-resolution mass spectrometry (HRMS), respectively. The ability of CF neutrophils to kill pseudomonas aeruginosa was also evaluated.

RESULTS

Polyunsaturated fatty acid metabolites analysis did not show any difference between CFTR^+/+ and CFTR^-/- neutrophils. On the other hand, a predictive mathematical model based on the ICM-MS proteomic profile was able to discriminate between both genotypes. Top-down proteomic analysis identified 19 m/z differentially abundant masses that corresponded mainly to proteins related to the antimicrobial response and the generation of reactive oxygen species (ROS). However, no alteration in the ability of CFTR^-/- neutrophils to kill pseudomonas aeruginosa in vitro was observed.

CONCLUSIONS

ICM-MS demonstrated that CFTR^-/- neutrophils present intrinsic alterations already at birth, before the presence of any infection or inflammation.

Predicting the microbial cause of community-acquired pneumonia: can physicians or a data-driven method differentiate viral from bacterial pneumonia at patient presentation?

BACKGROUND

Community-acquired pneumonia (CAP) requires urgent and specific antimicrobial therapy. However, the causal pathogen is typically unknown at the point when anti-infective therapeutics must be initiated. Physicians synthesize information from diverse data streams to make appropriate decisions. Artificial intelligence (AI) excels at finding complex relationships in large volumes of data. We aimed to evaluate the abilities of experienced physicians and AI to answer this question at patient admission: is it a viral or a bacterial pneumonia?

METHODS

We included patients hospitalized for CAP and recorded all data available in the first 3-h period of care (clinical, biological and radiological information). For this proof-of-concept investigation, we decided to study only CAP caused by a singular and identified pathogen. We built a machine learning model prediction using all collected data. Finally, an independent validation set of samples was used to test the pathogen prediction performance of: (i) a panel of three experts and (ii) the AI algorithm. Both were blinded regarding the final microbial diagnosis. Positive likelihood ratio (LR) values > 10 and negative LR values < 0.1 were considered clinically relevant.

RESULTS

We included 153 patients with CAP (70.6% men; 62 [51-73] years old; mean SAPSII, 37 [27-47]), 37% had viral pneumonia, 24% had bacterial pneumonia, 20% had a co-infection and 19% had no identified respiratory pathogen. We performed the analysis on 93 patients as co-pathogen and no-pathogen cases were excluded. The discriminant abilities of the AI approach were low to moderate (LR+ = 2.12 for viral and 6.29 for bacterial pneumonia), and the discriminant abilities of the experts were very low to low (LR+ = 3.81 for viral and 1.89 for bacterial pneumonia).

CONCLUSION

Neither experts nor an AI algorithm can predict the microbial etiology of CAP within the first hours of hospitalization when there is an urgent need to define the anti-infective therapeutic strategy.

Pneumonia recovery reprograms the alveolar macrophage pool

Community-acquired pneumonia is a widespread disease with significant morbidity and mortality. Alveolar macrophages are tissue-resident lung cells that play a crucial role in innate immunity against bacteria that cause pneumonia. We hypothesized that alveolar macrophages display adaptive characteristics after resolution of bacterial pneumonia. We studied mice 1 to 6 months after self-limiting lung infections with Streptococcus pneumoniae, the most common cause of bacterial pneumonia. Alveolar macrophages, but not other myeloid cells, recovered from the lung showed long-term modifications of their surface marker phenotype. The remodeling of alveolar macrophages was (a) long-lasting (still observed 6 months after infection), (b) regionally localized (observed only in the affected lobe after lobar pneumonia), and (c) associated with macrophage-dependent enhanced protection against another pneumococcal serotype. Metabolomic and transcriptomic profiling revealed that alveolar macrophages of mice that recovered from pneumonia had new baseline activities and altered responses to infection that better resembled those of adult humans. The enhanced lung protection after mild and self-limiting bacterial respiratory infections includes a profound remodeling of the alveolar macrophage pool that is long-lasting; compartmentalized; and manifest across surface receptors, metabolites, and both resting and stimulated transcriptomes.

Benefit-to-risk balance of bronchoalveolar lavage in the critically ill. A prospective, multicenter cohort study

Purpose

To assess the benefit-to-risk balance of bronchoalveolar lavage (BAL) in intensive care unit (ICU) patients.

Methods

In 16 ICUs, we prospectively collected adverse events during or within 24 h after BAL and assessed the BAL input for decision making in consecutive adult patients. The occurrence of a clinical adverse event at least of grade 3, i.e., sufficiently severe to need therapeutic action(s), including modification(s) in respiratory support, defined poor BAL tolerance. The BAL input for decision making was declared satisfactory if it allowed to interrupt or initiate one or several treatments.

Results

We included 483 BAL in 483 patients [age 63 years (interquartile range (IQR) 53–72); female gender: 162 (33.5%); simplified acute physiology score II: 48 (IQR 37-61); immunosuppression 244 (50.5%)]. BAL was begun in non-intubated patients in 105 (21.7%) cases. Sixty-seven (13.9%) patients reached the grade 3 of adverse event or higher. Logistic regression showed that a BAL performed by a non-experienced physician (non-pulmonologist, or intensivist with less than 10 years in the specialty or less than 50 BAL performed) was the main predictor of poor BAL tolerance in non-intubated patients [OR: 3.57 (95% confidence interval 1.04–12.35); P = 0.04]. A satisfactory BAL input for decision making was observed in 227 (47.0%) cases and was not predictable using logistic regression.

Conclusions

Adverse events related to BAL in ICU patients are not infrequent nor necessarily benign. Our findings call for an extreme caution, when envisaging a BAL in ICU patients and for a mandatory accompaniment of the less experienced physicians.

Electronic supplementary material

The online version of this article (10.1007/s00134-019-05896-4) contains supplementary material, which is available to authorized users.

CFTR-deficient pigs display alterations of bone microarchitecture and composition at birth

BACKGROUND

The lack of cystic fibrosis transmembrane conductance regulator (CFTR) function causes cystic fibrosis (CF), predisposing to severe lung disease, reduced growth and osteopenia. Both reduced bone content and strength are increasingly recognized in infants with CF before the onset of significant lung disease, suggesting a developmental origin and a possible role in bone disease pathogenesis. The role of CFTR in bone metabolism is unclear and studies on humans are not feasible. Deletion of CFTR in pigs (CFTR ^-/- pigs) displays at birth severe malformations similar to humans in the intestine, respiratory tract, pancreas, liver, and male reproductive tract.

METHODS

We compared bone parameters of CFTR ^-/- male and female pigs with those of their wild-type (WT) littermates at birth. Morphological and microstructural properties of femoral cortical and trabecular bone were evaluated using micro-computed tomography (μCT), and their chemical compositions were examined using Raman microspectroscopy.

RESULTS

The integrity of the CFTR ^-/- bone was altered due to changes in its microstructure and chemical composition in both sexes. Low cortical thickness and high cortical porosity were found in CFTR ^-/- pigs compared to sex-matched WT littermates. Moreover, an increased chemical composition heterogeneity associated with higher carbonate/phosphate ratio and higher mineral crystallinity was found in CFTR ^-/- trabecular bone, but not in CFTR ^-/- cortical bone.

CONCLUSIONS

The loss of CFTR directly alters the bone composition and metabolism of newborn pigs. Based on these findings, we speculate that bone defects in patients with CF could be a primary, rather than a secondary consequence of inflammation and infection.

Healthcare trajectories before and after critical illness: population-based insight on diverse patients clusters

BACKGROUND

The post intensive care syndrome (PICS) gathers various disabilities, associated with a substantial healthcare use. However, patients' comorbidities and active medical conditions prior to intensive care unit (ICU) admission may partly drive healthcare use after ICU discharge. To better understand retative contribution of critical illness and PICS-compared to pre-existing comorbidities-as potential determinant of post-critical illness healthcare use, we conducted a population-based evaluation of patients' healthcare use trajectories.

RESULTS

Using discharge databases in a 2.5-million-people region in France, we retrieved, over 3 years, all adult patients admitted in ICU for septic shock or acute respiratory distress syndrome (ARDS), intubated at least 5 days and discharged alive from hospital: 882 patients were included. Median duration of mechanical ventilation was 11 days (interquartile ranges [IQR] 8;20), mean SAPS2 was 49, and median hospital length of stay was 42 days (IQR 29;64). Healthcare use (days spent in healthcare facilities) was analyzed 2 years before and 2 years after ICU admission. Prior to ICU admission, we observed, at the scale of the whole study population, a progressive increase in healthcare use. Healthcare trajectories were then explored at individual level, and patients were assembled according to their individual pre-ICU healthcare use trajectory by clusterization with the K-Means method. Interestingly, this revealed diverse trajectories, identifying patients with elevated and increasing healthcare use (n = 126), and two main groups with low (n = 476) or no (n = 251) pre-ICU healthcare use. In ICU, however, SAPS2, duration of mechanical ventilation and length of stay were not different across the groups. Analysis of post-ICU healthcare trajectories for each group revealed that patients with low or no pre-ICU healthcare (which represented 83% of the population) switched to a persistent and elevated healthcare use during the 2 years post-ICU.

CONCLUSION

For 83% of ARDS/septic shock survivors, critical illness appears to have a pivotal role in healthcare trajectories, with a switch from a low and stable healthcare use prior to ICU to a sustained higher healthcare recourse 2 years after ICU discharge. This underpins the hypothesis of long-term critical illness and PICS-related quantifiable consequences in healthcare use, measurable at a population level.

Acute respiratory infection hospitalized in intensive care unit: long-term outcome in Elderly

Background

The consequences of the ageing population concerning ICU-hospitalization need to be adequately described, especially acute respiratory infections (ARI) strongly associated with Elderly. The study aimed to assess the long-term outcomes of ARI surviving ICU hospitalization in patients over 80 yo.

Methods

A retrospective multicentre cohort study was performed, based on hospital discharge databases in one French region (2.5 million inhabitants). Patients with ARI in ICU were selected according to specific ICD-10 diagnosis codes recorded and matched with a control population (patient undergoing a cataract surgery), using a propensity score (matching algorithm 1:1 ratio, caliper 0.002) with the matching variables (age, sex, frailty score, chronic heart disease, chronic pulmonary disease and cancer). Analyzes of this matched population were performed to determine their 2-year in-hospital mortality, healthcare utilization and evolution of the frailty score during the 2-year period before/after the inclusion stay.

Results

A total of 1,658 hospital stays for ARI after 80 yo were identified, with 438 dead (26%) during the initial stay. After matching with the cataract population, 988 patients were selected in each group without difference in the propensity score. ARI lead to an important increase of healthcare use during the 2 years after discharge. The patients that were discharged from hospital after ARI requiring ICU, had a 23-fold increase of death at 90 days and 4-fold at 2 years and the evolution of the frailty score was 1.6 fold higher than the cataract population.

Conclusions

Elderly patients with severe ARI survived from their ICU stay in 75%, but have a major risk of death in the following months, and an important increase in healthcare consumption. Our findings provide data for more informed goals-of-care discussions and may help target post-ICU discharge services for these high-risk groups.

Key messages

Elderly patients with severe acute respiratory infection survived ICU in 75%, but had a major risk of death in the following months, added to a substantial increase in healthcare consumption. These findings provide data for more informed goals-of-care discussions and may help target interventions for these high-risk groups.

Pseudomonas aeruginosa Lipoxygenase LoxA Contributes to Lung Infection by Altering the Host Immune Lipid Signaling

Pseudomonas aeruginosa is an opportunistic bacteria and a major cause of nosocomial pneumonia. P. aeruginosa has many virulence factors contributing to its ability to colonize the host. LoxA is a lipoxygenase enzyme secreted by P. aeruginosa that oxidizes polyunsaturated fatty acids. Based on previous in vitro biochemical studies, several biological roles of LoxA have been hypothesized, including interference of the host lipid signaling, and modulation of bacterial invasion properties. However, the contribution of LoxA to P. aeruginosa lung pathogenesis per se remained unclear. In this study, we used complementary in vitro and in vivo approaches, clinical strains of P. aeruginosa as well as lipidomics technology to investigate the role of LoxA in lung infection. We found that several P. aeruginosa clinical isolates express LoxA. When secreted in the lungs, LoxA processes a wide range of host polyunsaturated fatty acids, which further results in the production of bioactive lipid mediators (including lipoxin A₄). LoxA also inhibits the expression of major chemokines (e.g., MIPs and KC) and the recruitment of key leukocytes. Remarkably, LoxA promotes P. aeruginosa persistence in lungs tissues. Hence, our study suggests that LoxA-dependent interference of the host lipid pathways may contribute to P. aeruginosa lung pathogenesis.

Preclinical septic shock research: why we need an animal ICU

Animal experiments are widely used in preclinical medical research with the goal of disease modeling and exploration of novel therapeutic approaches. In the context of sepsis and septic shock, the translation into clinical practice has been disappointing. Classical animal models of septic shock usually involve one-sex-one-age animal models, mostly in mice or rats, contrasting with the heterogeneous population of septic shock patients. Many other factors limit the reliability of preclinical models and may contribute to preclinical research failure in critical care, including the host specificity of several pathogens, the fact that laboratory animals are raised in pathogen-free facilities and that organ support techniques are either absent or minimal. Advanced animal models have been developed with the aim of improving the clinical translatability of experimental findings. So-called animal ICUs refer to the preclinical investigation of adult or even aged animals of either sex, using—in case of rats and mice—miniaturized equipment allowing for reproducing an ICU environment at a small animal scale and integrating chronic comorbidities to more closely reflect the clinical conditions studied. Strength and limitations of preclinical animal models designed to decipher the mechanisms involved in septic cardiomyopathy are discussed. This article reviews the current status and the challenges of setting up an animal ICU.

Intra-tracheal amikacin spray delivery in healthy mechanically ventilated piglets

BACKGROUND

Nebulization during mechanical ventilation is impeded by large extra-pulmonary drug deposition and long administration durations which currently limit implementation of inhaled antibiotic therapy. Direct intra-tracheal delivery using a sprayer represents an appealing alternative investigated in small animal models, but large animal data are lacking.

METHODS

Amikacin was administered through intravenous infusion (20 mg/kg), nebulization (60 mg/kg) and direct intra-tracheal spray (30 mg/kg) to 10 intubated piglets, in a randomized cross-over design. Amikacin concentrations were measured in the serum and pulmonary parenchyma. Anatomic deposition was investigated using immuno-histochemistry.

RESULTS

Spray delivery resulted in higher amikacin outputs than nebulization and infusion. Pulmonary inhaled delivery techniques yielded much higher lung concentrations and much lower serum concentrations than intravenous infusion. However, unlike nebulization and infusion, intra-tracheal spray delivery was associated with more than 100- and 1000-fold variability in lung concentrations between and within animals. Amikacin specific immuno-histochemistry showed consistent bronchial and alveolar drug deposition with all modalities.

CONCLUSION

Nebulization remains the most reliable and simple technique to deliver inhaled amikacin uniformly to the lung during mechanical ventilation. Further development of tracheal sprays is required to take advantage of potential benefits related to high drug output and low extra-pulmonary deposition in large animals.

Exploring the fate of inhaled monoclonal antibody in the lung parenchyma by microdialysis

Therapeutic antibodies (Abs) are emerging as major drugs to treat respiratory diseases, and inhalation may provide substantial benefits for their delivery. Understanding the behavior of Abs after pulmonary deposition is critical for their development. We investigated the pharmacokinetics of a nebulized Ab by continuous sampling in lung parenchyma using microdialysis in non-human primates. We defined the optimal conditions for microdialysis of Ab and demonstrated that lung microdialysis of Ab is feasible over a period of several days. The concentration-profile indicated a two-phase non-linear elimination and/or distribution of inhaled mAbX. Lung exposition was higher than the systemic one over a period of 33 hours and above MabX affinity for its target. The microdialysis results were supported by an excellent relationship with dosages from lung extracts.