Association of COVID-19 inflammation with activation of the C5a-C5aR1 axis.

Coronavirus disease 2019 (COVID-19) is a disease caused by infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and has resulted in a pandemic1. The C5a complement factor and its receptor C5aR1 (also known as CD88) have a key role in the initiation and maintenance of several inflammatory responses by recruiting and activating neutrophils and monocytes1. Here we provide a longitudinal analysis of immune responses, including phenotypic analyses of immune cells and assessments of the soluble factors that are present in the blood and bronchoalveolar lavage fluid of patients at various stages of COVID-19 severity, including those who were paucisymptomatic or had pneumonia or acute respiratory distress syndrome. The levels of soluble C5a were increased in proportion to the severity of COVID-19 and high expression levels of C5aR1 receptors were found in blood and pulmonary myeloid cells, which supports a role for the C5a-C5aR1 axis in the pathophysiology of acute respiratory distress syndrome. Anti-C5aR1 therapeutic monoclonal antibodies prevented the C5a-mediated recruitment and activation of human myeloid cells, and inhibited acute lung injury in human C5aR1 knock-in mice. These results suggest that blockade of the C5a-C5aR1 axis could be used to limit the infiltration of myeloid cells in damaged organs and prevent the excessive lung inflammation and endothelialitis that are associated with acute respiratory distress syndrome in patients with COVID-19.

Severe 25E-NBOH intoxication associated with MDPHP intake: a case report, metabolism study, and literature review.

N-Benzylphenethylamine derivatives are 5-HT2A receptor agonists with hallucinogenic properties, including NBOMe (N-(2-methoxybenzyl)-2-(3,4,5-trimethoxyphenyl)ethan-1-amine) and NBOH (2-(((2,5-dimethoxyphenethyl)amino)methyl)phenol). We reported here the case of a 23-year-old man who presented a serotoninergic syndrome and a loss of consciousness following the consumption of a powder labelled as 25I-NBOH. Toxicological analyses of biological samples were carried out using a liquid chromatography high-resolution mass spectrometry. Two new psychoactive substances were identified and confirmed with certified reference materials: 25E-NBOH (2-(((4-ethyl-2,5-dimethoxyphenethyl)amino)methyl)phenol) and MDPHP (1-(benzo[d][1,3]dioxol-5-yl)-2-(pyrrolidin-1-yl)hexan-1-one). Pharmaceuticals administered to the patient during his medical care were found in plasma and urine. 25E-NBOH and MDPHP concentrations were respectively at 2.3 ng/mL and 3.4 ng/mL in plasma, and 25.7 ng/mL and 30.5 ng/mL in urine. 25I-NBOH (2-(((4-iodo-2,5-dimethoxyphenethyl)amino)methyl)phenol) was specifically searched in both samples and was not detected. These results are discussed along with a literature review on human cases of exposure to N-benzylphenethylamine derivatives. Using molecular networking approach, we propose the first 25E-NBOH metabolism study using authentic biological samples (plasma and urine). We described seven metabolites (M1 to M7), including two phase I (m/z 330.172; m/z 288.160) and five phase II metabolites (m/z 464.191, m/z 478.207, m/z 492.223, m/z 508.218; m/z 396.156). The M6 (m/z 492.223) was the most intense ion detected in plasma and urine and could be proposed as a relevant 25E-NBOH consumption marker. Overall, we described an original case of 25E-NBOH poisoning and identified metabolites that could potentially be used as consumption markers to detect 25E-NBOH intoxications with a higher confidence level and probably a longer detection window.

Early IL-1 receptor blockade in severe inflammatory respiratory failure complicating COVID-19.

Around the tenth day after diagnosis, ∼20% of patients with coronavirus disease 2019 (COVID-19)-associated pneumonia evolve toward severe oxygen dependence (stage 2b) and acute respiratory distress syndrome (stage 3) associated with systemic inflammation often termed a "cytokine storm." Because interleukin-1 (IL-1) blocks the production of IL-6 and other proinflammatory cytokines, we treated COVID-19 patients early in the disease with the IL-1 receptor antagonist, anakinra. We retrospectively compared 22 patients from three different centers in France with stages 2b and 3 COVID-19-associated pneumonia presenting with acute severe respiratory failure and systemic inflammation who received either standard-of-care treatment alone (10 patients) or combined with intravenous anakinra (12 patients). Treatment started at 300 mg⋅d-1 for 5 d, then tapered with lower dosing over 3 d. Both populations were comparable for age, comorbidities, clinical stage, and elevated biomarkers of systemic inflammation. All of the patients treated with anakinra improved clinically (P < 0.01), with no deaths, significant decreases in oxygen requirements (P < 0.05), and more days without invasive mechanical ventilation (P < 0.06), compared with the control group. The effect of anakinra was rapid, as judged by significant decrease of fever and C-reactive protein at day 3. A mean total dose of 1,950 mg was infused with no adverse side effects or bacterial infection. We conclude that early blockade of the IL-1 receptor is therapeutic in acute hyperinflammatory respiratory failure in COVID-19 patients.

Complement cascade in severe forms of COVID-19: Recent advances in therapy.

The complement system is an essential component of the innate immune system. The three complement pathways (classical, lectin, alternative) are directly or indirectly activated by the SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2). In the most severe forms of COVID-19, overactivation of the complement system may contribute to the cytokine storm, endothelial inflammation (endotheliitis) and thrombosis. No antiviral drug has yet been shown to be effective in COVID-19. Therefore, immunotherapies represent a promising therapeutic in the immunopathological phase (following the viral phase) of the disease. Complement blockade, mostly C5a-C5aR axis blockade, may prevent acute respiratory distress syndrome (ARDS) from worsening or progression to death. Clinical trials are underway.

Avdoralimab (Anti-C5aR1 mAb) Versus Placebo in Patients With Severe COVID-19: Results From a Randomized Controlled Trial (FOR COVID Elimination [FORCE]).

OBJECTIVES: Severe COVID-19 is associated with exaggerated complement activation. We assessed the efficacy and safety of avdoralimab (an anti-C5aR1 mAb) in severe COVID-19. DESIGN: FOR COVID Elimination (FORCE) was a double-blind, placebo-controlled study. SETTING: Twelve clinical sites in France (ICU and general hospitals). PATIENTS: Patients receiving greater than or equal to 5 L oxygen/min to maintain Sp o2 greater than 93% (World Health Organization scale ≥ 5). Patients received conventional oxygen therapy or high-flow oxygen (HFO)/noninvasive ventilation (NIV) in cohort 1; HFO, NIV, or invasive mechanical ventilation (IMV) in cohort 2; and IMV in cohort 3. INTERVENTIONS: Patients were randomly assigned, in a 1:1 ratio, to receive avdoralimab or placebo. The primary outcome was clinical status on the World Health Organization ordinal scale at days 14 and 28 for cohorts 1 and 3, and the number of ventilator-free days at day 28 (VFD28) for cohort 2. MEASUREMENTS AND MAIN RESULTS: We randomized 207 patients: 99 in cohort 1, 49 in cohort 2, and 59 in cohort 3. During hospitalization, 95% of patients received glucocorticoids. Avdoralimab did not improve World Health Organization clinical scale score on days 14 and 28 (between-group difference on day 28 of -0.26 (95% CI, -1.2 to 0.7; p = 0.7) in cohort 1 and -0.28 (95% CI, -1.8 to 1.2; p = 0.6) in cohort 3). Avdoralimab did not improve VFD28 in cohort 2 (between-group difference of -6.3 (95% CI, -13.2 to 0.7; p = 0.96) or secondary outcomes in any cohort. No subgroup of interest was identified. CONCLUSIONS: In this randomized trial in hospitalized patients with severe COVID-19 pneumonia, avdoralimab did not significantly improve clinical status at days 14 and 28 (funded by Innate Pharma, ClinicalTrials.gov number, NCT04371367).

Functional and genetic testing in adults with HLH reveals an inflammatory profile rather than a cytotoxicity defect.

Hemophagocytic lymphohistiocytosis (HLH) is a life-threatening hyperinflammatory condition. Primary HLH occurs early in life as a result of monogenic biallelic mutations affecting lymphocyte cytotoxicity. Secondary HLH occurs mostly in adults secondary to infection, lymphoma, or rheumatic disease. In this latter setting, lymphocyte cytotoxicity status is not known. We conducted a systematic evaluation of natural killer (NK) cell cytotoxicity in adult patients with secondary HLH. Adult patients with secondary HLH were prospectively studied ex vivo for total lymphocyte count and subtype, NK cell phenotype, perforin expression and degranulation, and natural or antibody-dependent cell cytotoxicity, in comparison with patients affected by the same underlying disease without HLH (disease controls [DCs]) and with healthy controls (HCs). Screening for variants of cytotoxity genes was systematically performed. 68 patients were included in the HLH group and 34 each in the DC and HC groups. In HLH patients, severe and transient lymphopenia, activated NK cell phenotype (eg, increased CD69, ICAM-1, HLADR, and CCR5 expression), and decreased capacity of interferon γ production were observed; mean perforin expression was normal; and degranulation tests and NK cell cytotoxicity were not different from those in DCs. A monoallelic variant of uncertain significance affecting a lymphocyte cytotoxicity gene or the perforin variant A91V was observed in almost 50% of the patients. We detected no major intrinsic cytotoxicity dysfunction in secondary HLH patients compared with DCs and no predicted pathogenic gene variant. The activated NK phenotype profile associated with decreased interferon γ production seems similar to those of other hyperinflammatory diseases such as sepsis or systemic juvenile idiopathic arthritis.

The association between regional guidelines compliance and mortality in severe trauma patients: an observational, retrospective study.

BACKGROUND AND IMPORTANCE: Trauma is a major cause of mortality and morbidity. Regional trauma systems are the cornerstones of healthcare systems, helping to improve outcomes and avoid preventable deaths in severe trauma patients. OBJECTIVES: The goal of this study was to evaluate the association between compliance with the guidelines of a regional trauma management system and survival at 28 days of severe trauma patients. DESIGN, SETTINGS AND PARTICIPANTS: We conducted a retrospective observational study from 1 January 2019 to 31 December 2019. All adult patients admitted for trauma at the University Hospital of Marseille (France) and requiring a pre-hospital medical team were analysed. Compliance with a list of 30 items based on the regional guidelines for the trauma management was evaluated. Each item was classified as compliant, not compliant or not applicable. The global compliance was calculated for each patient as the ratio between the number of compliant items over the number of applicable items. OUTCOME MEASURES AND ANALYSIS: The primary aim was to measure the association between compliance with the guidelines and survival at 28 days using a logistic regression. Secondary objectives were to measure the association between compliance with the guidelines and survival at 28 days and 6 months according to the severity of the patients, using a cut-off of the injury severity score at 24. MAIN RESULTS: A total of 494 patients with a median age of 35.0 (25.0-50.0) years were analysed. Global compliance with guidelines was 63%. Mortality at 28 days and 6 months was assessed at 33 (6.7%) and 37 (7.5%) patients, respectively. The level of compliance was associated with reduced mortality at 28 days [odds ratio (OR) at 0.94 and 95% confidence interval (CI) at 0.89-0.98]. In the subgroup of 122 patients with an injury severity score above 23, the level of compliance was associated with reduced mortality at 28 days [OR: 0.93 (95% CI: 0.88-0.99)] and 6 months [OR: 0.93 (95% CI: 0.87-0.99)]. CONCLUSION: Increased levels of compliance with the guidelines in severe trauma patients were associated with an increase in survival, notably in the most severe patients.

Prospective Multicenter Study on Early Proximal Tubular Injury in COVID-19-Related Acute Respiratory Distress Syndrome.

Introduction: During COVID-19, renal impairment is associated with poor prognosis in intensive care unit (ICU). We aimed to assess the existence and incidence of early renal dysfunction and its prognostic value in patients with COVID-19-related acute respiratory distress syndrome (ARDS). Methods: In this prospective multicenter study, patients aged over 18 years with invasive mechanical ventilation (MV) for ARDS were enrolled in 3 ICUs. Precise evaluation of renal dysfunction markers, including urinary protein electrophoresis (UPE) and quantification, was performed within 24 hours after MV onset. Results: From March 2020 to December 2021, 135 patients were enrolled as follows: 100 with COVID-19 ARDS and 35 with non-COVID-19 ARDS. UPE found more tubular dysfunction in patients with COVID-19 (68% vs. 21.4%, P < 0.0001) and more normal profiles in patients without COVID-19 (65.0% vs. 11.2%, P = 0.0003). Patients with COVID-19 significantly displayed early urinary leakage of tubular proteins such as beta-2-microglobulin (ß2m) and free light chains, tended to display acute kidney injury (AKI) more frequently (51.0% vs. 34.3%, P = 0.088), had longer MV (20 vs. 9 days, P < 0.0001) and longer ICU stay (26 vs. 15 days, P < 0.0001). In COVID-19 ARDS, leakage of free lambda light chain was associated with the onset of Kidney Disease: Improving Global Outcomes (KDIGO) ≥2 AKI (odds ratio [OR]: 1.014, 95% confidence interval [CI] 1.003-1.025, P = 0.011). Conclusion: Patients with COVID-19-related ARDS display a proximal tubular dysfunction before the onset of AKI, which predicts AKI. Proximal tubular damage seems an important mechanism of COVID-19-induced nephropathy. Analysis of urinary proteins is a reliable noninvasive tool to assess proximal tubular dysfunction in the ICU.

Ventilator Acquired Pneumonia in COVID-19 ICU Patients: A Retrospective Cohort Study during Pandemia in France.

Describe the characteristics of ventilation-acquired pneumonia (VAP) and potential risk factors in critically ill SARS-CoV-2 patients admitted in three French public hospitals during the first year of the COVID-19 pandemic. We conducted a monocentric retrospective study in seven Marseille intensive care units (ICUs) aiming to describe VAP characteristics and identify their risk factors. VAP patients were compared to a non-VAP control group. From March to November 2020, 161 patients admitted for viral-induced acute respiratory failure (ARF) requiring invasive mechanical ventilation (IMV) were included. This cohort was categorized in two groups according to the development or not of a VAP during their stay in ICU. 82 patients (51%) developed ventilation-acquired pneumonia. Most of them were men (77%) and 55% had hypertension. In the VAP population, 31 out of 82 patients (38%) had received dexamethasone and 47% were administered antibiotic course prior to ICU admission. An amount of 88% of respiratory infections were late VAPs with a median delay of 10 days from the onset of IMV. Gram negative bacteria were responsible for 62% of VAPs with Pseudomonas spp. being the most documented bacteria. Less than a third of the ICU-acquired infections were due to multidrug resistant (MDR) bacteria mainly displaying AmpC cephalosporin hyper production resistance phenotype. Multivariate analysis revealed that early Dexamethasone administration in ICU, male sex, older age and ROX score were risk factors for VAP whereas pre-ICU antimicrobial treatment and higher IGS 2 were protective factors. VAP is a frequent ICU-related complication affecting half of patients infected with SARS-CoV-2 and requiring IMV. It was responsible for increased morbidity due to a longer ICU and hospital stay. VAP risk factors included demographic factors such as age and sex. Dexamethasone was associated with a threefold greater risk of developing VAP during ICU stay. These results need to be comforted by large multi-centric studies before questioning the only available and effective treatment against SARS-CoV-2 in ICU patients.

Salivary Alpha Amylase Bronchial Measure for Early Aspiration Pneumonia Diagnosis in Patients Treated With Therapeutic Hypothermia After Out-of-hospital Cardiac Arrest.

Background: Aspiration pneumonia is the most common respiratory complication following out-of-hospital cardiac arrests (OHCA). Alpha-amylase (α-amylase) in pulmonary secretions is a biomarker of interest in detecting inhalation. The main goal of this study is to evaluate the performance of bronchoalveolar levels of α-amylase in early diagnosis of aspiration pneumonia, in patients admitted to intensive care unit (ICU) after OHCA. Methods: This is a prospective single-center trial, led during 5 years (July 2015 to September 2020). We included patients admitted to ICU after OHCA. A protected specimen bronchial brushing and a mini-bronchoalveolar lavage (mini-BAL) were collected during the first 6 h after admission. Dosage of bronchial α-amylase and standard bacterial analysis were performed. Investigators confirmed pneumonia diagnosis using clinical, radiological, and microbiological criteria. Every patient underwent targeted temperature management. Results: 88 patients were included. The 34% (30 patients) developed aspiration pneumonia within 5 days following admission. The 55% (17) of pneumonias occurred during the first 48 h. The 57% of the patients received a prophylactic antibiotic treatment on their admission day. ICU mortality was 50%. Median value of bronchial α-amylase did not differ whether patients had aspiration pneumonia (15 [0-94]) or not (3 [0-61], p = 0,157). Values were significantly different concerning early-onset pneumonia (within 48 h) [19 (7-297) vs. 3 (0-82), p = 0,047]. If one or more microorganisms were detected in the initial mini-BAL, median value of α-amylase was significantly higher [25 (2-230)] than in sterile cultures (2 [0-43], p = 0,007). With an 8.5 IU/L cut-point, sensitivity and specificity of α-amylase value for predicting aspiration pneumonia during the first 2 days were respectively 74 and 62%. True positive and negative rates were respectively 44 and 86%. The area under the ROC curve was 0,654 (CI 95%; 0,524-0,785). Mechanical ventilation duration, length of ICU stay, and mortality were similar in both groups. Conclusion: In our study, dosage of bronchial α-amylase was not useful in predicting aspiration pneumonia within the first 5 days after ICU admission for OHCA. Performance in predicting early-onset pneumonia was moderate.

Immune Checkpoint Inhibitor-Induced Myositis/Myocarditis with Myasthenia Gravis-like Misleading Presentation: A Case Series in Intensive Care Unit.

INTRODUCTION: Immune checkpoint inhibitors (ICIs) are a major breakthrough in cancer treatment. Their increasingly frequent use leads to an uprising incidence of immune-related adverse events (irAEs). Among those, myocarditis is the most reported fatal cardiovascular irAE, frequently associated with ICI-related myositis. CASE SERIES: Here, we report three cases of ICI-induced myocarditis/myositis with an extremely severe myasthenia gravis-like (MG-like) presentation, highlighting the main challenges in irAEs management. These patients were over 60 years old and presented an ongoing melanoma, either locally advanced or metastatic, treated with ICI combinations. Shortly after the first or second ICI infusion, they were admitted in an intensive care unit (ICU) for grade 3 ICI-induced MG-like symptoms leading to acute respiratory failure (ARF) requiring invasive mechanical ventilation (IMV). The initial misdiagnosis was later corrected to severe ICI-induced seronegative myocarditis/myositis upon biological results and histopathology from muscular/endomyocardial biopsies. All of them received urgent high-dose corticosteroids pulses. The oldest patient died prematurely, but the two others received targeted therapies leading to complete recovery for one of them. DISCUSSION: These cases highlight the four main challenges of irAEs, encompassing the lack of knowledge among physicians, the risk of misdiagnosis due to numerous and non-specific symptoms, the frequent overlapping forms of irAEs, and the extremely rare MG-like misleading presentation of myocarditis/myositis. The exact pathophysiology of irAEs remains unclear, although a major involvement of the lymphoid compartment (specifically T lymphocytes) was evidenced. Therapeutic management is based on urgent high-dose corticosteroids. For the severest forms of irAEs, case-by-case targeted immunosuppressive therapies should be urgently administered upon multidisciplinary meetings. CONCLUSION: These cases highlight the lack of knowledge of irAEs among physicians, aggravated by misleading overlapping forms, requiring specific management in trained units and multidisciplinary care. Severe MG-like presentation of irAEs constitutes an absolute therapeutic emergency with high-dose corticosteroids and targeted immunosuppressive therapy.

Two Venovenous Extracorporeal Membrane Oxygenation for One Gunshot.

Venovenous extracorporeal membrane oxygenation (VV-ECMO) is an adjuvant treatment for severe acute respiratory distress syndrome (ARDS) with refractory hypoxemia. Contraindications to therapeutic anticoagulation must be ruled out prior to ECMO implementation. We report the case of a 17-year-old male admitted in intensive care unit (ICU) for penetrating chest trauma due to multiple gunshot wounds. The body computed tomography (body CT scan) documented right pulmonary contusions and a homolateral hemothorax. His condition rapidly deteriorated with refractory hypoxemia due to lung contusion requiring invasive mechanical ventilation (IMV) and polytransfused hemorrhagic shock. During his stay in ICU, venovenous ECMO (VV-ECMO) was implemented twice, firstly for trauma-induced ARDS and secondly after thoracic surgery. This case emphasizes the successful use of VV-ECMO in posttraumatic ARDS without increasing the risk of bleeding.

Eosinopenia as Predictor of Poor Outcome in Hospitalized COVID-19 Adult Patients from Waves 1 and 2 of 2020 Pandemic.

During SARS-CoV-2 infection, eosinopenia may reflect a hyperactive immune response. In this study of hospitalized COVID-19 patients, we aimed to better understand the prognostic value of severe eosinopenia (absolute eosinophil count = 0 G/L) and decipher its underlying mechanisms. We retrospectively analyzed the records of COVID-19 patients hospitalized from March to June 2020 in three university hospitals in Marseille, France. We assessed the association between severe eosinopenia and a composite poor outcome in these patients, including the need for oxygen supplementation at >6 L/min, ICU admission, and in-hospital death. Among the 551 COVID-19 patients included in this study, severe eosinopenia was found in 228 (51%) of them on admission to hospital and was associated with a composite poor outcome using multivariate analysis (OR = 2.58; CI95 [1.77−3.75]; p < 0.0001). We found a significant association between the presence of severe eosinopenia on admission and the elevation in C-reactive protein, ferritin, IP-10, and suPAR. The histological findings in a series of 37 autopsies from patients who died from severe COVID-19 and presented with severe eosinopenia showed no pulmonary eosinophil trapping. Severe eosinopenia can be a reliable biomarker associated with a composite poor outcome in hospitalized COVID-19 adult patients. It may reflect the magnitude of immune hyperactivation during severe-to-critical COVID-19.

Impact of Dexamethasone and Inhaled Nitric Oxide on Severe Acute Kidney Injury in Critically Ill Patients with COVID-19.

Background: Acute kidney injury (AKI) is the second most frequent condition after acute respiratory distress syndrome (ARDS) in critically ill patients with severe COVID-19 and is strongly associated with mortality. The aim of this multicentric study was to assess the impact of the specific treatments of COVID-19 and ARDS on the risk of severe AKI in critically ill COVID-19 patients. Methods: In this cohort study, data from consecutive patients older than 18 years admitted to 6 ICUs for COVID-19-related ARDS requiring invasive mechanical ventilation were included. The incidence and severity of AKI, defined according to the 2012 KDIGO definition, were monitored during the entire ICU stay until day 90. Patients older than 18 years admitted to the ICU for COVID-19-related ARDS requiring invasive mechanical ventilation were included. Results: 164 patients were included in the final analysis; 97 (59.1%) displayed AKI, of which 39 (23.8%) had severe stage 3 AKI, and 21 (12.8%) required renal replacement therapy (RRT). In univariate analysis, severe AKI was associated with angiotensin-converting enzyme inhibitors (ACEI) exposure (p = 0.016), arterial hypertension (p = 0.029), APACHE-II score (p = 0.004) and mortality at D28 (p = 0.008), D60 (p < 0.001) and D90 (p < 0.001). In multivariate analysis, the factors associated with the onset of stage 3 AKI were: exposure to ACEI (OR: 4.238 (1.307−13.736), p = 0.016), APACHE II score (without age) (OR: 1.138 (1.044−1.241), p = 0.003) and iNO (OR: 5.694 (1.953−16.606), p = 0.001). Prone positioning (OR: 0.234 (0.057−0.967), p = 0.045) and dexamethasone (OR: 0.194 (0.053−0.713), p = 0.014) were associated with a decreased risk of severe AKI. Conclusions: Dexamethasone was associated with the prevention of the risk of severe AKI and RRT, and iNO was associated with severe AKI and RRT in critically ill patients with COVID-19. iNO should be used with caution in COVID-19-related ARDS.

[Involvement of the complement cascade in severe forms of COVID-19]. / Implication de la cascade du complément dans les formes sévères de COVID-19.

The complement system is an essential component of the innate immune system. Its excessive activation during COVID-19 contributes to cytokine storm, disease-specific endothelial inflammation (endotheliitis) and thrombosis that comes with the disease. Targeted therapies of complement inhibition in COVID-19, in particular blocking the C5a-C5aR1 axis have to be taken into account in the establishment of potential biomarkers and development of therapeutic strategies in the most severe forms of the disease.

TITLE: Implication de la cascade du complément dans les formes sévères de COVID-19. ABSTRACT: Le système du complément est un composant essentiel du système immunitaire inné. Son activation excessive au cours de la COVID-19 participe à l'orage cytokinique, à l'inflammation endothéliale (endothélite) et aux thromboses qui accompagnent la maladie. Bloquer le complément, notamment l'axe C5a-C5aR1, par des thérapies spécifiques représente un espoir thérapeutique dans les formes les plus sévères de la maladie.

High Mortality of HLH in ICU Regardless Etiology or Treatment.

Background: Adult hemophagocytic lymphohistiocytosis (HLH) is highly lethal in the ICU. The diagnostic and therapeutic emergency that HLH represents is compounded by its unknown pathophysiological mechanisms. Here, we report on a large cohort of adult HLH in the ICU (ICU-HLH). We analyzed prognostic factors associated with mortality to define the diagnostic and therapeutic challenges in this specific population. Methods: This retrospective study included adult patients diagnosed with HLH in four ICUs in Marseille, France between 2010 and 2020. Patients who fulfilled the HLH-2004 criteria (≥ 4/8) and/or had an HScore ≥ 169 were diagnosed with HLH. HLH was categorized into four groups according to etiology: sepsis-associated HLH, intracellular infection-associated HLH, malignancy-associated HLH, and idiopathic HLH. Results: Two hundred and sixty patients were included: 121 sepsis-associated HLH (47%), 84 intracellular infection-associated HLH (32%), 28 malignancy-associated HLH (11%), and 27 idiopathic HLH (10%). The ICU mortality rate reached 57% (n = 147/260) without a statistical difference between etiological groups. Independent factors associated with mortality in multivariate analysis included age (OR (5 years) = 1.31 [1.16-1.48], p < 0.0001), SOFA score at ICU admission (OR = 1.37 [1.21-1.56], p < 0.0001), degradation of the SOFA score between ICU arrival and HLH diagnosis (Delta SOFA) (OR = 1.47 [1.28-1.70], p < 0.0001), the presence of bone-marrow hemophagocytosis (OR = 5.27 [1.11-24.97], p = 0.04), highly severe anemia (OR = 1.44 [1.09-1.91], p = 0.01), and hypofibrinogenemia (OR = 1.21 [1.04-1.41], p = 0.02). Conclusions: In this large retrospective cohort study of critically ill patients, ICU-HLH in adults was associated with a 57% mortality rate, regardless of HLH etiology or specific treatment. Factors independently associated with prognosis included age, presence of hemophagocytosis in bone-marrow aspirates, organ failure at admission, and worsening organ failure during the ICU stay. Whether a rapid diagnosis and the efficacy of specific therapy improve outcome is yet to be prospectively investigated.

Factors Associated with 90-Day Mortality in Invasively Ventilated Patients with COVID-19 in Marseille, France.

OBJECTIVES: To describe clinical characteristics and management of intensive care units (ICU) patients with laboratory-confirmed COVID-19 and to determine 90-day mortality after ICU admission and associated risk factors. METHODS: This observational retrospective study was conducted in six intensive care units (ICUs) in three university hospitals in Marseille, France. Between 10 March and 10 May 2020, all adult patients admitted in ICU with laboratory-confirmed SARS-CoV-2 and respiratory failure were eligible for inclusion. The statistical analysis was focused on the mechanically ventilated patients. The primary outcome was the 90-day mortality after ICU admission. RESULTS: Included in the study were 172 patients with COVID-19 related respiratory failure, 117 of whom (67%) received invasive mechanical ventilation. 90-day mortality of the invasively ventilated patients was 27.4%. Median duration of ventilation and median length of stay in ICU for these patients were 20 (9-33) days and 29 (17-46) days. Mortality increased with the severity of ARDS at ICU admission. After multivariable analysis was carried out, risk factors associated with 90-day mortality were age, elevated Charlson comorbidity index, chronic statins intake and occurrence of an arterial thrombosis. CONCLUSION: In this cohort, age and number of comorbidities were the main predictors of mortality in invasively ventilated patients. The only modifiable factor associated with mortality in multivariate analysis was arterial thrombosis.

Imbalance of Circulating Innate Lymphoid Cell Subpopulations in Patients With Septic Shock.

Background: Septic shock, a major cause of death in critical care, is the clinical translation of a cytokine storm in response to infection. It can be complicated by sepsis-induced immunosuppression, exemplified by blood lymphopenia, an excess of circulating Treg lymphocytes, and decreased HLA-DR expression on circulating monocytes. Such immunosuppression is associated with secondary infections, and higher mortality. The effect of these biological modifications on circulating innate lymphoid cells (ILCs) has been little studied. Methods: We prospectively enrolled patients with septic shock (Sepsis-3 definition) in the intensive care unit (ICU) of Timone CHU Hospital. ICU controls (trauma, cardiac arrest, neurological dysfunction) were recruited at the same time (NCT03297203). We performed immunophenotyping of adaptive lymphocytes (CD3+ T cells, CD19+ B cells, CD4+CD25+FoxP3+ Treg lymphocytes), ILCs (CD3-CD56+ NK cells and helper ILCs - ILC1, ILC2, and ILC3), and monocytes by flow cytometry on fresh blood samples collected between 24 and 72 h after admission. Results: We investigated adaptive and innate circulating lymphoid cells in the peripheral blood of 18 patients in septic shock, 15 ICU controls, and 30 healthy subjects. As expected, the peripheral blood lymphocytes of all ICU patients showed lymphopenia, which was not specific to sepsis, whereas those of the healthy volunteers did not. Circulating CD3+ T cells and CD3-CD56+ NK cells were mainly concerned. There was a tendency toward fewer Treg lymphocytes and lower HLA-DR expression on monocytes in ICU patients with sepsis. Although the ILC1 count was higher in septic patients than healthy subjects, ILC2, and ILC3 counts were lower in both ICU groups. However, ILC3s within the total ILCs were overrepresented in patients with septic shock. The depression of immune responses has been correlated with the occurrence of secondary infections. We did not find any differences in ILC distribution according to this criterion. Conclusion: All ICU patients exhibit lymphopenia, regardless of the nature (septic or sterile) of the initial medical condition. Specific distribution of circulating ILCs, with an excess of ILC1, and a lack of ILC3, may characterize septic shock during the first 3 days of the disease.