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Background: Myeloid-derived suppressor cells (MDSCs) are immature myeloid cells with immunosuppressive functions sub-classified into monocytic and polymorphonuclear MDSCs (M-MDSCs and PMN-MDSCs). Clinical studies reported increased levels of MDSCs that were associated with poor outcome in sepsis patients. Since sepsis patients exhibit signs of inflammation and immunosuppression, MDSCs may provide benefit by dampening deleterious inflammation in some patients. To test this hypothesis, we measured MDSCs in critically ill sepsis patients with pneumonia and multi-organ dysfunctions and a high likelihood of death., Methods: This was a prospective multicenter observational cohort study performed in eight ICUs in Athens and Thessaloniki, Greece, enrolling critically ill patients with pneumonia and sepsis with multi-organ dysfunctions. A flow cytometry approach using blood collected at study inclusion in tubes containing lyophilized antibodies combined to unsupervised clustering was developed to quantify M-MDSCs and PMN-MDSCs., Results: Forty-eight patients were included, of whom 34 died within 90 days. At study inclusion, M-MDSCs and PMN-MDSCs were increased in sepsis patients when compared to healthy subjects (3.07% vs 0.96% and 22% vs 2.1% of leukocytes, respectively; p < 10 -4 ). Increased PMN-MDSCs were associated with secondary infections (p = 0.024) and new sepsis episodes (p = 0.036). M-MDSCs were more abundant in survivors than in patients who died within 28 days (p = 0.028). Stratification of patients according to M-MDSC levels revealed that high levels of M-MDSC were associated with reduced 90-day mortality (high vs low M-MDSCs: 47% vs 84% mortality, p = 0.003, hazard ratio [HR] = 3.2, 95% CI 1.4-7.2). Combining high M-MDSC levels with low Acute Physiology and Chronic Health Evaluation (APACHE) II score improved patient stratification (M-MDSCs high /APACHE II low vs M-MDSCs low /APACHE II low : 20% vs 80% 90-day mortality, p = 0.0096, HR = 7.2, 95% CI 1.6-32). In multivariate analyses high M-MDSCs remained correlated with improved survival in patients with low APACHE II score (p = 0.05, HR = 5.26, 95% CI 1.0-27.8)., Conclusion: This is the first study to associate high levels of M-MDSCs with improved survival in sepsis patients., (© 2022. The Author(s).)

Predicting the severity of COVID-19 remains an unmet medical need. Our objective was to develop a blood-based host-gene-expression classifier for the severity of viral infections and validate it in independent data, including COVID-19. We developed a logistic regression-based classifier for the severity of viral infections and validated it in multiple viral infection settings including COVID-19. We used training data (N = 705) from 21 retrospective transcriptomic clinical studies of influenza and other viral illnesses looking at a preselected panel of host immune response messenger RNAs. We selected 6 host RNAs and trained logistic regression classifier with a cross-validation area under curve of 0.90 for predicting 30-day mortality in viral illnesses. Next, in 1417 samples across 21 independent retrospective cohorts the locked 6-RNA classifier had an area under curve of 0.94 for discriminating patients with severe vs. non-severe infection. Next, in independent cohorts of prospectively (N = 97) and retrospectively (N = 100) enrolled patients with confirmed COVID-19, the classifier had an area under curve of 0.89 and 0.87, respectively, for identifying patients with severe respiratory failure or 30-day mortality. Finally, we developed a loop-mediated isothermal gene expression assay for the 6-messenger-RNA panel to facilitate implementation as a rapid assay. With further study, the classifier could assist in the risk assessment of COVID-19 and other acute viral infections patients to determine severity and level of care, thereby improving patient management and reducing healthcare burden., (© 2022. The Author(s).)

Background: Macrophage activation-like syndrome (MALS) and complex immune dysregulation (CID) often underlie acute respiratory distress (ARDS) in COVID-19. We aimed to investigate the effect of personalized immunotherapy on clinical improvement of critical COVID-19., Methods: In this open-label prospective trial, 102 patients with ARDS by SARS-CoV-2 were screened for MALS (ferritin >4,420 ng/mL) and CID (ferritin ≤4,420 ng/mL and low human leukocyte antigen (HLA)-DR expression on CD14-monocytes). Patients with MALS or CID with increased aminotransferases received intravenous anakinra; those with CID and normal aminotransferases received tocilizumab. The primary outcome was ≥25% decrease in the Sequential Organ Failure Assessment (SOFA) score and/or 50% increase in the respiratory ratio by day 8; 28-day mortality, change of SOFA score by day 28, serum biomarkers, and cytokine production by mononuclear cells were secondary endpoints., Results: The primary study endpoint was met in 58.3% of anakinra-treated patients and in 33.3% of tocilizumab-treated patients (p: 0.01). Most patients in both groups received dexamethasone as standard of care. No differences were found in secondary outcomes, mortality, and SOFA score changes. Ferritin decreased among anakinra-treated patients; interleukin-6, soluble urokinase plasminogen activator receptor, and HLA-DR expression increased among tocilizumab-treated patients. Survivors by day 28 who received anakinra were distributed to lower severity levels of the WHO clinical progression scale. Greater incidence of secondary infections was found with tocilizumab treatment., Conclusion: Immune assessment resulted in favorable anakinra responses among critically ill patients with COVID-19 and features of MALS., (© 2021 The Author(s). Published by S. Karger AG, Basel.)

The role of probiotics in the prevention of ventilator-associated pneumonia (VAP) remains inconclusive. The aim of this study was to assess the efficacy of a probiotic regimen for VAP prophylaxis in mechanically ventilated multi-trauma patients, intubated immediately after the injurious insult. In a randomized, placebo-controlled study enrolling multi-trauma patients, patients expected to require mechanical ventilation for >10 days were assigned at random to receive prophylaxis with a probiotic formula (n=59) or placebo (n=53). The probiotic formula was a preparation of Lactobacillus acidophilus LA-5 [1.75 × 10 9 colony-forming units (cfu)], Lactobacillus plantarum (0.5 × 10 9 cfu), Bifidobacterium lactis BB-12 (1.75 × 10 9 cfu) and Saccharomyces boulardii (1.5 × 10 9 cfu) in sachets. Each patient received two sachets twice daily for 15 days: one through the nasogastric tube and one spread on the oropharynx. The incidence of VAP was the primary endpoint. The incidence of other infections and sepsis, and the duration of hospital stay were the secondary endpoints. Administration of probiotics reduced the incidence of VAP [11.9% vs 28.3%, hazard ratio (HR) 0.34, 95% confidence interval (CI) 0.13-0.92; P=0.034] and sepsis [6.8% vs 24.5%, odds ratio 0.22, 95% CI 0.07-0.74: P=0.016]. Furthermore, probiotic prophylaxis reduced the time of stay in the intensive care unit (ICU) and the length of hospital stay. The prophylactic use of probiotics with a combination of enteral and topical application to the oropharynx had a positive effect on the incidence of VAP and sepsis, as well as on ICU and total hospital stay in patients receiving protracted mechanical ventilation., (Copyright © 2021 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Acute respiratory distress syndrome (ARDS) in COVID-19 has been associated with catastrophic inflammation. We present measurements in humans and a new animal model implicating a role in danger-associated molecular patterns. Calprotectin (S100A8/A9) and high-mobility group box 1 (HMGB1) were measured in patients without/with ARDS, and admission calprotectin was associated with soluble urokinase plasminogen activator receptor (suPAR). An animal model was developed by intravenous injection of plasma from healthy or patients with COVID-19 ARDS into C57/BL6 mice once daily for 3 consecutive days. Mice were treated with one anti-S100A8/A9 antibody, the IL-1 receptor antagonist anakinra or vehicle, and Flo1-2a anti-murine anti-IL-1α monoclonal antibody or the specific antihuman IL-1α antibody XB2001 or isotype controls. Cytokines and myeloperoxidase (MPO) were measured in tissues. Calprotectin, but not HMGB1, was elevated in ARDS. Higher suPAR indicated higher calprotectin. Animal challenge with COVID-19 plasma led to inflammatory reactions in murine lung and intestines as evidenced by increased levels of TNFα, IL-6, IFNγ, and MPO. Lung inflammation was attenuated with anti-S100A8/A9 pre-treatment. Anakinra treatment restored these levels. Similar decrease was found in mice treated with Flo1-2a but not with XB2001. Circulating alarmins, specifically calprotectin, of critically ill COVID-19 patients induces tissue-specific inflammatory responses through an IL-1-mediated mechanism. This could be attenuated through inhibition of IL-1 receptor or of IL-1α., (© 2022 The Author(s). Published by S. Karger AG, Basel.)

Background Use of angiotensin-converting enzyme inhibitors and angiotensin receptor blockers (ACEi/ARB) is thought to affect COVID-19 through modulating levels of angiotensin-converting enzyme 2, the cell entry receptor for SARS-CoV2. We sought to assess the association between ACEi/ARB, biomarkers of inflammation, and outcomes in patients hospitalized for COVID-19. Methods and Results We leveraged the ISIC (International Study of Inflammation in COVID-19), identified patients admitted for symptomatic COVID-19 between February 1, 2020 and June 1, 2021 for COVID-19, and examined the association between in-hospital ACEi/ARB use and all-cause death, need for ventilation, and need for dialysis. We estimated the causal effect of ACEi/ARB on the composite outcomes using marginal structural models accounting for serial blood pressure and serum creatinine measures. Of 2044 patients in ISIC, 1686 patients met inclusion criteria, of whom 398 (23.6%) patients who were previously on ACEi/ARB received at least 1 dose during their hospitalization for COVID-19. There were 215 deaths, 407 patients requiring mechanical ventilation, and 124 patients who required dialysis during their hospitalization. Prior ACEi/ARB use was associated with lower levels of soluble urokinase plasminogen activator receptor and C-reactive protein. In multivariable analysis, in-hospital ACEi/ARB use was associated with a lower risk of the composite outcome of in-hospital death, mechanical ventilation, or dialysis (adjusted hazard ratio 0.49, 95% CI [0.36-0.65]). Conclusions In patients hospitalized for COVID-19, ACEi/ARB use was associated with lower levels of inflammation and lower risk of in-hospital outcomes. Clinical trials will define the role of ACEi/ARB in the treatment of COVID-19. Registration URL: https://www.clinicaltrials.gov; Unique identifier: NCT04818866.

Introduction: The anti-inflammatory effect of macrolides prompted the study of oral clarithromycin in moderate COVID-19., Methods: An open-label non-randomized trial in 90 patients with COVID-19 of moderate severity was conducted between May and October 2020. The primary endpoint was defined at the end of treatment (EOT) as no need for hospital re-admission and no progression into lower respiratory tract infection (LRTI) for patients with upper respiratory tract infection and as at least 50% decrease of the respiratory symptoms score without progression into severe respiratory failure (SRF) for patients with LRTI. Viral load, biomarkers, the function of mononuclear cells and safety were assessed., Results: The primary endpoint was attained in 86.7% of patients treated with clarithromycin (95% CIs 78.1-92.2%); this was 91.7% and 81.4% among patients starting clarithromycin the first 5 days from symptoms onset or later (odds ratio after multivariate analysis 6.62; p 0.030). The responses were better for patients infected by non-B1.1 variants. Clarithromycin use was associated with decreases in circulating C-reactive protein, tumour necrosis factor-alpha and interleukin (IL)-6; by increase of production of interferon-gamma and decrease of production of interleukin-6 by mononuclear cells; and by suppression of SARS-CoV-2 viral load. No safety concerns were reported., Conclusions: Early clarithromycin treatment provides most of the clinical improvement in moderate COVID-19., Trial Registration: ClinicalTrials.gov, NCT04398004., (© 2021. The Author(s).)

Objective: Coronavirus disease 2019 is a heterogeneous disease most frequently causing respiratory tract infection, which can induce respiratory failure and multiple organ dysfunction syndrome in its severe forms. The prevalence of coronavirus disease 2019-related sepsis is still unclear; we aimed to describe this in a systematic review., Data Sources: MEDLINE (PubMed), Cochrane, and Google Scholar databases were searched based on a prespecified protocol (International Prospective Register for Systematic Reviews: CRD42020202018)., Study Selection: Studies reporting on patients with confirmed coronavirus disease 2019 diagnosed with sepsis according to sepsis-3 or according to the presence of infection-related organ dysfunctions necessitating organ support/replacement were included in the analysis. The primary end point was prevalence of coronavirus disease 2019-related sepsis among adults hospitalized in the ICU and the general ward. Among secondary end points were the need for ICU admission among patients initially hospitalized in the general ward and the prevalence of new onset of organ dysfunction in the ICU. Outcomes were expressed as proportions with respective 95% CI., Data Extraction: Two reviewers independently screened and reviewed existing literature and assessed study quality with the Newcastle-Ottawa Scale and the Methodological index for nonrandomized studies., Data Synthesis: Of 3,825 articles, 151 were analyzed, only five of which directly reported sepsis prevalence. Noting the high heterogeneity observed, coronavirus disease 2019-related sepsis prevalence was 77.9% (95% CI, 75.9-79.8; I2 = 91%; 57 studies) in the ICU, and 33.3% (95% CI, 30.3-36.4; I2 = 99%; 86 studies) in the general ward. ICU admission was required for 17.7% (95% CI, 12.9-23.6; I2 = 100%) of ward patients. Acute respiratory distress syndrome was the most common organ dysfunction in the ICU (87.5%; 95% CI, 83.3-90.7; I2 = 98%)., Conclusions: The majority of coronavirus disease 2019 patients hospitalized in the ICU meet Sepsis-3 criteria and present infection-associated organ dysfunction. The medical and scientific community should be aware and systematically report viral sepsis for prognostic and treatment implications., Competing Interests: Dr. Karakike received funding from the Horizon 2020 Marie Skłodowska-Curie Grant European Sepsis Academy (grant 676129). Dr. Netea’s institution received funding from Roche; he received funding form an ERC Advanced Grant (833247), a Spinoza grant of the Netherlands Organization for Scientific Research, TTxD, GSK, and ViiV HealthCare; he disclosed he is on the scientific Advisory Board at Trained Therapeutic and Discovery; received independent educational grants from AbbVie, Abbott CH, Astellas Pharma Europe, AxisShield, bioMérieux, InflaRx GmbH, the Medicines Company, and XBiotech. Dr. Reinhart disclosed that he was the President of the Global Sepsis Alliance and that he is a shareholder of InflaRx NV, a Jena/Germany-based Biotech Company that evaluates an immune-modulatory approach for the adjunctive treatment of coronavirus disease 2019. Dr. Giamarellos-Bourboulis’ institution received funding from the Framework 7 Program, HemoSpec (granted to the National and Kapodistrian University of Athens), the Horizon 2020 Marie-Curie Project European Sepsis Academy (granted to the National and Kapodistrian University of Athens), and the Horizon 2020 European Grant ImmunoSep (granted to the Hellenic Institute for the Study of Sepsis); he received funding from AbbVie, United States; Abbott CH; Angelini; Astellas Pharma; AxisShield; bioMérieux; Biotest; Brahms GmbH; InflaRx GmbH; MSD Greece; XBiotech; and The Medicines Company; independent educational grants from AbbVie, Abbott CH, Astellas Pharma Europe, AxisShield, bioMérieux, InflaRx GmbH, the Medicines Company, and XBiotech. The remaining authors have disclosed that they do not have any potential conflicts of interest., (Copyright © 2021 by the Society of Critical Care Medicine and Wolters Kluwer Health, Inc. All Rights Reserved.)

Background: We aimed to investigate the potential beneficial effect of immunomodulation therapy on the thromboembolic risk in hospitalized COVID-19 patients., Methods: We searched PubMed and Scopus for randomized trials reporting the outcomes of venous thromboembolism (VTE), ischemic stroke or systemic embolism, myocardial infarction, any thromboembolic event, and all-cause mortality in COVID-19 patients treated with immunomodulatory agents. Odds ratios (OR) and 95% confidence intervals (CI) were calculated using the Mantel-Haenszel random effects method., Results: Among 8499 patients hospitalized with COVID-19, 4638 were treated with an immunomodulatory agent, 3861-with usual care only. Among the patients prescribed immunomodulatory agents, there were 1.77 VTEs per 100 patient-months compared to 2.30 among those treated with usual care (OR: 0.84, 95% CI: 0.61-1.16; I 2 : 0%). Among the patients who received an interleukin 6 (IL-6) antagonist, VTEs were reported in 12 among the 1075 patients compared to 20 among the 848 receiving the usual care (OR: 0.52, 95% CI: 0.22-1.20; I 2 : 6%). Immunomodulators as an add-on to usual care did not reduce the risk of stroke or systemic embolism (OR: 1.10, 95% CI: 0.50-2.40; I 2 : 0%) or of myocardial infarction (OR: 1.06, 95% CI: 0.47-2.39; I 2 : 0%) and there was a nonsignificant reduction in any thromboembolic event (OR: 0.86, 95% CI: 0.65-1.14; I 2 : 0%)., Conclusions: We did not identify a statistically significant effect of immunomodulation on prevention of thromboembolic events in COVID-19. However, given the large effect estimate for VTE prevention, especially in the patients treated with IL-6 antagonists, we cannot exclude a potential effect of immunomodulation.

Abstract: Further improvement of the diagnostic and prognostic performance of biomarkers for the critically ill is needed. Procalcitonin (PCT), placental growth factor (PlGF) and soluble fms-like tyrosine kinase-1 raise interest for sepsis diagnosis and prognosis.Serum samples from 2 cohorts of 172 patients (derivation cohort) and of 164 patients (validation cohort) comprising only patients with microbiologically confirmed gram-negative infections were analyzed. PlGF, s-Flt-1 and procalcitonin (PCT) were measured in serum within 24 hours from sepsis onset and repeated on days 3 and 7.PCT and s-Flt-1 baseline levels were higher in sepsis and septic shock compared to non-sepsis; this was not the case for PlGF. s-Flt-1 at concentrations greater than 60 pg/ml diagnosed sepsis with sensitivity 72.3% and specificity 54.9% whereas at concentrations greater than 70 pg/ml predicted unfavorable outcome with specificity 73.0% and sensitivity 63.7%. At least 80% decrease of PCT and/or PCT less than 0.5 ng/ml on day 7 was protective from sepsis-associated death.Both s-Flt-1 and PCT should be measured in the critically ill since they provide additive information for sepsis diagnosis and prognosis.ClinicalTrials.gov numbers NCT01223690 and NCT00297674., Competing Interests: E.J. Giamarellos-Bourboulis has received honoraria from Abbott CH, Brahms GmbH, bioMérieux Inc, InflaRx GmbH, MSD Greece, Sobi and XBiotech Inc; independent educational grants from Abbott CH, Astellas Pharma Europe, AxisShield, bioMérieux Inc, InflaRx GmbH, Sobi and XBiotech Inc.; and funding from the FrameWork 7 program HemoSpec (granted to the National and Kapodistrian University of Athens), the Horizon2020 Marie-Curie Project European Sepsis Academy (granted to the National and Kapodistrian University of Athens), and the Horizon 2020 European Grants ImmunoSep and RISKinCOVID (granted to the Hellenic Institute for the Study of Sepsis). The other authors have no conflicts of interest to disclose., (Copyright © 2021 the Author(s). Published by Wolters Kluwer Health, Inc.)

Importance: Surgery is a mainstay in the management of hidradenitis suppurativa (HS). Adalimumab is the first drug approved for HS., Objective: To investigate the efficacy and safety of adalimumab in combination with wide-excision surgery followed by secondary intention healing., Design, Setting, and Participants: The Safety and Efficacy of Adalimumab for Hidradenitis Suppurativa Peri-Surgically (SHARPS) trial was a phase 4, randomized, double-blind, placebo-controlled study of adalimumab in conjunction with surgery. Patients were enrolled in 45 sites across 20 countries from July 18, 2016, to February 2, 2019, with the last patient visit on October 16, 2019. Eligible patients (aged 18-65 years) had moderate to severe HS that required radical surgery in an axillary or inguinal region and had 2 other anatomical regions affected, with 1 or more regions at Hurley stage II or III. Analysis was conducted in November 2019., Interventions: Patients were randomized 1:1 to receive continuous adalimumab, 40 mg, or placebo during presurgery (12 weeks), perioperative (2 weeks), and postoperative (10 weeks) periods., Main Outcomes and Measures: The primary end point was the proportion of patients achieving HS clinical response across all body regions at week 12., Results: Overall, 103 patients were randomized to adalimumab and 103 to matching placebo. Among all patients, 51% (n = 106) were women, 94% (n = 193) were White, and the mean (SD) age was 37.6 (11.3) years. At week 12, significantly more patients receiving adalimumab (49 of 103 [48%]) vs placebo (35 of 103 [34%]; P = .049) achieved HS clinical response across all body regions (treatment difference, 14% [95% CI, 0%-27%]). Treatment-emergent adverse events were reported in 74 of 103 patients (72%) and 69 of 103 patients (67%) in the adalimumab and placebo groups, respectively. No increased risk of postoperative wound infection, complication, or hemorrhage was observed with adalimumab vs placebo. Two deaths occurred in the adalimumab group; neither was considered as having a reasonable possibility of relationship to study drug., Conclusions and Relevance: Adalimumab was efficacious in conjunction with wide-excision surgery followed by secondary intention healing, with no need to interrupt treatment prior to surgery. These data support further investigation of adalimumab as an adjuvant therapy to surgery in patients with moderate to severe HS., Trial Registration: ClinicalTrials.gov Identifier: NCT02808975.

Competing Interests: Declaration of Competing Interest E. J. Giamarellos-Bourboulis has received honoraria from Abbott CH, bioMérieux, Brahms GmbH, GSK, InflaRx GmbH, Sobi and XBiotech Inc; independent educational grants from Abbott CH, bioMérieux Inc, InflaRx GmbH, Johnson & Johnson, MSD, Novartis, UCB, Sobi and XBiotech Inc.; and funding from the Horizon2020 Marie-Curie Project European Sepsis Academy (granted to the National and Kapodistrian University of Athens), and the Horizon 2020 European Grants ImmunoSep and RISKinCOVID (granted to the Hellenic Institute for the Study of Sepsis).

Intergenerational inheritance of immune traits linked to epigenetic modifications has been demonstrated in plants and invertebrates. Here we provide evidence for transmission of trained immunity across generations to murine progeny that survived a sublethal systemic infection with Candida albicans or a zymosan challenge. The progeny of trained mice exhibited cellular, developmental, transcriptional and epigenetic changes associated with the bone marrow-resident myeloid effector and progenitor cell compartment. Moreover, the progeny of trained mice showed enhanced responsiveness to endotoxin challenge, alongside improved protection against systemic heterologous Escherichia coli and Listeria monocytogenes infections. Sperm DNA of parental male mice intravenously infected with the fungus C. albicans showed DNA methylation differences linked to immune gene loci. These results provide evidence for inheritance of trained immunity in mammals, enhancing protection against infections., (© 2021. The Author(s), under exclusive licence to Springer Nature America, Inc.)

Early increase of soluble urokinase plasminogen activator receptor (suPAR) serum levels is indicative of increased risk of progression of coronavirus disease 2019 (COVID-19) to respiratory failure. The SAVE-MORE double-blind, randomized controlled trial evaluated the efficacy and safety of anakinra, an IL-1α/β inhibitor, in 594 patients with COVID-19 at risk of progressing to respiratory failure as identified by plasma suPAR ≥6 ng ml -1 , 85.9% (n = 510) of whom were receiving dexamethasone. At day 28, the adjusted proportional odds of having a worse clinical status (assessed by the 11-point World Health Organization Clinical Progression Scale (WHO-CPS)) with anakinra, as compared to placebo, was 0.36 (95% confidence interval 0.26-0.50). The median WHO-CPS decrease on day 28 from baseline in the placebo and anakinra groups was 3 and 4 points, respectively (odds ratio (OR) = 0.40, P < 0.0001); the respective median decrease of Sequential Organ Failure Assessment (SOFA) score on day 7 from baseline was 0 and 1 points (OR = 0.63, P = 0.004). Twenty-eight-day mortality decreased (hazard ratio = 0.45, P = 0.045), and hospital stay was shorter., (© 2021. The Author(s).)

Background: Anakinra might improve the prognosis of patients with moderate to severe COVID-19 (ie, patients requiring oxygen supplementation but not yet receiving organ support). We aimed to assess the effect of anakinra treatment on mortality in patients admitted to hospital with COVID-19., Methods: For this systematic review and individual patient-level meta-analysis, a systematic literature search was done on Dec 28, 2020, in Medline (PubMed), Cochrane, medRxiv, bioRxiv, and the ClinicalTrials.gov databases for randomised trials, comparative studies, and observational studies of patients admitted to hospital with COVID-19, comparing administration of anakinra with standard of care, or placebo, or both. The search was repeated on Jan 22, 2021. Individual patient-level data were requested from investigators and corresponding authors of eligible studies; if individual patient-level data were not available, published data were extracted from the original reports. The primary endpoint was mortality after 28 days and the secondary endpoint was safety (eg, the risk of secondary infections). This study is registered on PROSPERO (CRD42020221491)., Findings: 209 articles were identified, of which 178 full-text articles fulfilled screening criteria and were assessed. Aggregate data on 1185 patients from nine studies were analysed, and individual patient-level data on 895 patients were provided from six of these studies. Eight studies were observational and one was a randomised controlled trial. Most studies used historical controls. In the individual patient-level meta-analysis, after adjusting for age, comorbidities, baseline ratio of the arterial partial oxygen pressure divided by the fraction of inspired oxygen (PaO 2 /FiO 2 ), C-reactive protein (CRP) concentrations, and lymphopenia, mortality was significantly lower in patients treated with anakinra (38 [11%] of 342) than in those receiving standard of care with or without placebo (137 [25%] of 553; adjusted odds ratio [OR] 0·32 [95% CI 0·20-0·51]). The mortality benefit was similar across subgroups regardless of comorbidities (ie, diabetes), ferritin concentrations, or the baseline PaO 2 /FiO 2 . In a subgroup analysis, anakinra was more effective in lowering mortality in patients with CRP concentrations higher than 100 mg/L (OR 0·28 [95% CI 0·17-0·47]). Anakinra showed a significant survival benefit when given without dexamethasone (OR 0·23 [95% CI 0·12-0·43]), but not with dexamethasone co-administration (0·72 [95% CI 0·37-1·41]). Anakinra was not associated with a significantly increased risk of secondary infections when compared with standard of care (OR 1·35 [95% CI 0·59-3·10])., Interpretation: Anakinra could be a safe, anti-inflammatory treatment option to reduce the mortality risk in patients admitted to hospital with moderate to severe COVID-19 pneumonia, especially in the presence of signs of hyperinflammation such as CRP concentrations higher than 100 mg/L., Funding: Sobi., Competing Interests: EJG-B has received honoraria from AbbVie USA, Abbott CH, Biotest Germany, Brahms, InflaRx, MSD Greece, XBiotech, and Angelini Italy; independent educational grants from AbbVie, Abbott CH, Astellas Pharma Europe, AxisShield, bioMérieux, InflaRx, the Medicines Company and XBiotech; and funding from the FrameWork 7 program HemoSpec (granted to the National and Kapodistrian University of Athens), the Horizon2020 Marie-Curie Project European Sepsis Academy (granted to the National and Kapodistrian University of Athens), and the Horizon 2020 European Grant ImmunoSep (granted to the Hellenic Institute for the Study of Sepsis). MG has received speakers' fees and unrestricted grants from Novartis and Sobi. PP, MKo, and EKo are funded by a COVID-19 grant paid to the Radboud University Medical Center (Radboudumc). JE-O is a co-founder, shareholder, and CSO of ViroGates, Denmark, and named inventor on patents on suPAR owned by Copenhagen University Hospital Hvidovre, Denmark. GK has received from ROCHE-CHUGAI Research Grants (<€20 000), fees from Sobi France for scientific presentations (<€4000) and participated in a SOBI Advisory Board on COVID (unpaid) and in an OLATEC Monitoring Board (unpaid). GCa has received speakers' and consulting fees from Novartis and Sobi. LD has received grants (paid to LD's institution outside the current work) from AbbVie, Bristol-Myers Squibb, Celgene, GlaxoSmithKline, Janssen, Kiniksa, Merk Sharp & Dohme, Mundipharma Pharmaceuticals, Novartis, Pfizer, Roche, Sanofi Genzyme, and Sobi; and consulting fees from AbbVie, Amgen, Biogen, Bristol-Myers Squibb, Celltrion, Galapagos, GlaxoSmithKline, Kiniksa, Novartis, Pfizer, Roche, Sanofi-Genzyme, and Sobi. GH reports consultancy fees from Bristol-Myers Squibb, Lilly, Novartis; speakers' fees from AbbVie, Bristol-Myers-Squibb, Celgene, Lilly, Novartis, Pfizer, Roche, Sanofi-Aventis; support for attending meetings from Bristol-Myers-Squibb, Fresenius-Kabi, Janssen-Cilag, Lilly, Mylan, Roche, UCB; and participation on advisory boards for Bristol-Myers-Squibb and Lilly. FV has received (via the Institut de Recherche pour le Développement) Horizon 2020-EDCTP-European Grants: PANDORA and ITAIL-COVID. All other authors declare no competing interests., (© 2021 Elsevier Ltd. All rights reserved.)

Background: Sepsis represents a life-threatening syndrome characterized by a cytokine storm. Whether cytokine levels are related to the susceptibility pattern of invasive micro-organism remains a matter of debate. The purpose of this study is to investigate the immune response in multidrug resistant (MDR) and non-MDR sepsis patients by measuring cytokine levels, compare the outcome and determine predictors of mortality., Materials and Methods: A total of 128 septic patients, treated in intensive care unit (ICU) were enrolled in the study. Epidemiological and ICU data were recorded. Plasma concentrations of angiopoietin-2 (Ang-2), interleukin (IL)-6, IL-10, tumour necrosis factor-α (TNF-α) and soluble triggering receptor expressed on myeloid cells-1 (sTREM-1) were measured on admission., Results: A total of 90 patients suffered from non-MDR and 38 from MDR gram-negative sepsis. Levels of TNF-α were significantly higher ( p  = .017) in non-MDR sepsis patients. All pro-inflammatory cytokines were significantly increased in severely ill patients compared to patients with lower acute physiology and chronic health evaluation (APACHE) II score. MDR positive patients had a significantly lower 28-d survival ( p  = .008). Factors that were independently associated with higher 28-d mortality were carbapenem resistance (OR 5.38 [1.032 - 28.12], p  = .046), male gender (OR 2.76 [1.156 - 6.588], p  = .022), APACHE II score (OR 1.126 [1.048 - 1.21], p  = .001) and Ang-2 (OR 1.025 [1.001 - 20.1], p  = .048)., Conclusions: Sepsis evolution and outcome are influenced by multiple factors. Although MDR pathogens induced a weaker immune response characterized by lower TNF-α levels this was not accompanied by better survival. Increased Ang-2 levels, APACHE II score and carbapenem resistance are important factors associated with higher mortality.

Biochemical information from activated leukocytes provide valuable diagnostic information. In this study, Raman spectroscopy was applied as a label-free analytical technique to characterize the activation pattern of leukocyte subpopulations in an in vitro infection model. Neutrophils, monocytes, and lymphocytes were isolated from healthy volunteers and stimulated with heat-inactivated clinical isolates of Candida albicans , Staphylococcus aureus , and Klebsiella pneumoniae . Binary classification models could identify the presence of infection for monocytes and lymphocytes, classify the type of infection as bacterial or fungal for neutrophils, monocytes, and lymphocytes and distinguish the cause of infection as Gram-negative or Gram-positive bacteria in the monocyte subpopulation. Changes in single-cell Raman spectra, upon leukocyte stimulation, can be explained with biochemical changes due to the leukocyte's specific reaction to each type of pathogen. Raman spectra of leukocytes from the in vitro infection model were compared with spectra from leukocytes of patients with infection (DRKS-ID: DRKS00006265) with the same pathogen groups, and a good agreement was revealed. Our study elucidates the potential of Raman spectroscopy-based single-cell analysis for the differentiation of circulating leukocyte subtypes and identification of the infection by probing the molecular phenotype of those cells.

In light of the accumulating evidence for survival benefit coming from the use of macrolides for community-acquired pneumonia (CAP), a group of experts from the field of internal medicine and infectious diseases frame a position statement on the use of macrolides for the management of bacterial CAP and for infection by the novel coronavirus (COVID-19). The statement is framed taking into consideration existing publications and own research experience. The main content of this statement is that the combination of one β-lactam and a macrolide should be the first treatment of choice for patients with severe bacterial CAP. Severity is assessed as scoring 2 or more points on the CURB65 scoring system of severity or as pneumonia severity index III to V or C-reactive protein more than 150 mg/l; the suggested macrolide is either azithromycin or clarithromycin. The experts also suggest that in COVID-19 pneumonia, the combination of one β-lactam and a macrolide should be reserved only when there is strong suspicion of bacterial co-infection., (© 2021. The Author(s).)

Although in vitro data suggest that tigecycline is active against Klebsiella pneumoniae carbapenemase-producing K. pneumoniae (KPC-Kp), experimental and clinical data are limited. We studied the effect of tigecycline alone or in combination for experimental infections by KPC-Kp. A total of 540 male C57BL/6 mice were infected with three genetically diverse KPC-Kp isolates susceptible to tigecycline with meropenem minimum inhibitory concentrations (MICs) of 4, 16 and 256 μg/mL, respectively. Mice were randomly treated with water for injection, tigecycline, meropenem and colistin alone, and double or triple combinations of tigecycline, colistin and meropenem. Mouse survival was recorded for 14 days. In separate experiments, mice were sacrificed 6 h and 24 h after bacterial challenge for quantitative culture of tissues and serological analysis. Time-kill curves were performed. Tigecycline, colistin and meropenem concentrations were measured in tissues and serum by high-performance liquid chromatography (HPLC). Survival was significantly prolonged when mice were treated with tigecycline alone and tigecycline-containing regimens compared with control mice and mice treated with tigecycline-sparing regimens. Tigecycline-sparing regimens were active only against the isolate with a meropenem MIC of 4 μg/mL. Mortality was associated with progression to multiple organ failure. Tigecycline and tigecycline-containing regimens achieved a rapid decrease of bacterial loads both in tissues and in vitro. Tigecycline concentrations in tissues were negatively correlated with tissue bacterial load. Tigecycline alone or in combination with meropenem and/or colistin achieves effective treatment of experimental KPC-Kp infections irrespective of the meropenem MIC., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

Introduction: The epidemiology of severe lower respiratory tract infections (LRTI) is constantly changing. We aimed to describe it using the BioFire ® FilmArray ® Pneumonia plus (PNplus) Panel., Methods: In a sub-study of the PROGRESS trial, sputum samples of 90 patients with sepsis and LRTI were retrospectively studied. The primary endpoint was the comparative detection rate of pathogens between conventional microbiology and PNplus Panel; secondary endpoints were microbiology and the association with the inflammatory host response., Results: Fifty-six patients with community-acquired pneumonia without risk factors for multidrug-resistant (MDR) pathogens and another 34 patients with risk factors for MDR were studied; median pneumonia severity index (PSI) was 113 (88-135). PNplus detection rate was 72.2% compared to 10% by conventional microbiology (p < 0.001); Streptococcus pneumoniae was the most common pathogen. PSI and procalcitonin were greater among patients with bacterial pathogens than viral pathogens. Median procalcitonin was 0.49 ng/ml and 0.18 ng/ml among patients with ≥ 10 5 and < 10 5  copies/ml of detected bacteria, respectively (p = 0.004). Resistance reached 14.4%., Conclusion: PNplus detects severe pneumonia pathogens at a greater rate than conventional microbiology. High levels of inflammation accompany bacterial detection., Trial Registration: PROGRESS, ClinicalTrials.gov NCT03333304, 06/11/2017., (© 2021. The Author(s).)

Background: Severe coronavirus disease 2019 (COVID-19) is the result of a hyper-inflammatory reaction to the severe acute respiratory syndrome coronavirus 2. The biomarkers of inflammation have been used to risk-stratify patients with COVID-19. Osteopontin (OPN) is an integrin-binding glyco-phosphoprotein involved in the modulation of leukocyte activation; its levels are associated with worse outcomes in patients with sepsis. Whether OPN levels predict outcomes in COVID-19 is unknown., Methods: We measured OPN levels in serum of 341 hospitalized COVID-19 patients collected within 48 h from admission. We characterized the determinants of OPN levels and examined their association with in-hospital outcomes; notably death, need for mechanical ventilation, and need for renal replacement therapy (RRT) and as a composite outcome. The risk discrimination ability of OPN was compared with other inflammatory biomarkers., Results: Patients with COVID-19 (mean age 60, 61.9% male, 27.0% blacks) had significantly higher levels of serum OPN compared to healthy volunteers (96.63 vs. 16.56 ng/mL, p < 0.001). Overall, 104 patients required mechanical ventilation, 35 needed dialysis, and 53 died during their hospitalization. In multivariable analyses, OPN levels ≥140.66 ng/mL (third tertile) were associated with a 3.5 × (95%CI 1.44-8.27) increase in the odds of death, and 4.9 × (95%CI 2.48-9.80) increase in the odds of requiring mechanical ventilation. There was no association between OPN and need for RRT. Finally, OPN levels in the upper tertile turned out as an independent prognostic factor of event-free survival with respect to the composite endpoint., Conclusion: Higher OPN levels are associated with increased odds of death and mechanical ventilation in patients with COVID-19, however, their utility in triage is questionable.

Surgical site infections represent a considerable burden for healthcare systems. To obtain a consensus on the impact and future clinical and economic needs regarding SSI management in an era of multidrug resistance. A modified Delphi method was used to obtain consensus among experts from five European countries. The Delphi questionnaire was assembled by a steering committee, verified by a panel of experts and administered to 90 experts in 8 different surgical specialities (Abdominal, Cancer, Cardiac, General surgery, Orthopaedic, Thoracic, Transplant and Vascular and three other specialities (infectious disease, internal medicine microbiology). Respondents (n = 52) reached consensus on 62/73 items including that resistant pathogens are an increasing matter of concern and increase both treatment complexity and the length of hospital stay. There was strong positive consensus on the cost-effectiveness of early discharge (ED) programs, improvement of quality of life with ED and association between increased length of stay and economic burden to the hospital. However, established ED protocols were not widely available in their hospitals. Respondents expressed a positive consensus on the usefulness of antibiotics that allow ED. Surgeons are aware of their responsibility in an interdisciplinary team for the treatment of SSI, and of the impact of multidrug-resistant bacteria in the context of SSI. Reducing the length of hospital stays by applying ED protocols and implementing new treatment alternatives is crucial to reduce harm to patients and costs for the hospital., (© 2021. The Author(s).)

The therapeutic potential of IgM-enriched immunoglobulin preparations (IgGAM) in sepsis remains a field of debate. The use of polyclonal immunoglobulins as adjuvant therapy (Esen & Tugrul, 2009; Kaukonen et al., 2014; Molnár et al., 2013; Taccone et al., 2009) has been shown to improve clinical outcomes in terms of mortality. This study analyze the impact of IgM-enriched IgG (IgGM) as additional immunomodulation. Patients and methods: This is a retrospective registry of 1196 patients with severe sepsis and septic shock from nine Intensive Care Units in Colombia, from routine clinical practice; 220 patients treated with IgGAM were registered. Fully matched comparators for severity and type of infection selected among patients non-treated with IgGAM. Mortality after 28 days was 30.5% among IgGAM-treated patients and 40.5% among matched comparators. Results: Multivariate Cox regression analysis showed IgGAM treatment to be the only variable protective from death after 28 days (hazard ratio 0.62; 0.45-0.86; p: 0.004). Results reinforce the importance of IgGAM treatment for favorable outcome after septic shock and are in line with recent published meta-analyses. This study showed that treatment with IgGM in patients with sepsis was an independent modulator of the 28-day associated with a lower mortality., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Background: Tetracyclines and clindamycin plus rifampicin combination therapy are both considered first-line therapy in current hidradenitis suppurativa guidelines. However, evidence for their efficacy is drawn from small studies, often without validated outcomes., Objective: To assess the 12-week efficacy of oral tetracyclines and a combination of clindamycin and rifampicin., Methods: A prospective, international cohort study performed between October 2018 and August 2019., Results: In total, 63.6% of the included 283 patients received oral tetracyclines, and 36.4% were treated with clindamycin and rifampicin. Both groups showed a significant decrease in International Hidradenitis Suppurativa Severity Score System from baseline (both P < .001). The Hidradenitis Suppurativa Clinical Response (HiSCR) was achieved in 40.1% and 48.2% of patients, respectively (P = .26). Patient characteristics or disease severity were not associated with the attainment of HiSCR or the minimal clinically important differences for the Dermatology Life Quality Index and pain., Limitations: Cohort study. Respectively, 23.9% and 19.4% of patients had to be excluded from the HiSCR analysis for the tetracycline and combination therapy group because of a low abscess and nodule count at baseline., Conclusion: This study shows significant efficacy of both tetracycline treatment and clindamycin and rifampicin combination therapy after 12 weeks in patients with hidradenitis suppurativa. No significant differences in efficacy were observed between the 2 treatments, regardless of disease severity., Competing Interests: Conflicts of interest Dr Tzellos has reported relationships with AbbVie, UCB, and Sanofi Genzyme. Dr Guillem has received honoraria from AbbVie and Novartis as a consultant and has given nonpaid lectures for AbbVie, Brothier, Cicaplus, Coloplast, Inresa, and Novartis. Dr Giamarellos-Bourboulis has received honoraria from Abbott CH, Angelini Italy, bioMérieux Inc, InflaRx GmbH, MSD Greece, and XBiotech Inc; independent educational grants from AbbVie, Abbott, Astellas Pharma Europe, AxisShield, bioMérieux Inc, InflaRx GmbH, ThermoFisher Brahms GmbH, and XBiotech Inc; and funding from the FrameWork 7 program HemoSpec (granted to the National and Kapodistrian University of Athens), the Horizon2020 Marie-Curie Project European Sepsis Academy (granted to the National and Kapodistrian University of Athens), and the Horizon 2020 European Grant ImmunoSep (granted to the Hellenic Institute for the Study of Sepsis). Dr Jemec has received honoraria from AbbVie, Chemocentryx, Coloplast, Incyte, Inflarx, Kymera, Leo Pharma, Novartis, and UCB for participation on advisory boards; grants from AbbVie, AstraZeneca, Inflarx, Janssen-Cilag, Leo Pharma, Novartis, Regeneron, and Sanofi for participation as an investigator; speaker honoraria from AbbVie, Boehringer Ingelheim, Galderma, and Novartis; and unrestricted departmental grants from Leo Pharma and Novartis. Dr Katoulis has reported relationships with AbbVie, Novartis, Genesis Pharma, Mylan, Janssen, Leo Pharma, and Lilly. Dr Koenig was an investigator, speaker, or advisor for AbbVie, Braun-Stiftung, and Celgene. Dr Lazaridou has received speaker honoraria, and/or honoraria for participation in advisory boards, and/or grants from AbbVie, Novartis, Genesis Pharma, Mylan, Pfizer, Janssen, Leo Pharma, Roche, Lilly, UCB, and Sanofi. Dr Matusiak reports personal fees from AbbVie, Amgen, Galapagos, InflaRx, Janssen-Cilag, LEO, Menlo, Novartis, Pfizer, Pierre Fabre, Regeneron, Trevi, and UCB. Dr Pinter has been an investigator, speaker, or advisor for AbbVie, Almirall-Hermal, Amgen, Biogen Idec, Biontec, Boehringer Ingelheim, Celgene, GlaxoSmithKline, Eli Lilly, Galderma, Hexal, Janssen, LEO-Pharma, MC2, Medac, Merck Serono, Mitsubishi, MSD, Novartis, Pascoe, Pfizer, Tigercat Pharma, Regeneron, Roche, Sandoz Biopharmaceuticals, Sanofi-Genzyme, Schering-Plough, and UCB Pharma. Dr Romani has reported relationships with AbbVie, Novartis, Leo Pharma, Janssen, Almirall, and Isdín. Dr Saunte was paid as a consultant for advisory board meeting by AbbVie, Janssen, Sanofi, and Leo Pharma and received speaker honoraria and/or grants from AbbVie, Pfizer, Galderma, Novartis, and Leo Pharma during the last 5 years. Dr Szepietowski reports personal fees from AbbVie, Amgen, Galapagos, InflaRx, Janssen-Cilag, LEO, Menlo, Novartis, Pfizer, Pierre Fabre, Regeneron, Sandoz, Sanofi, Sienna, Trevi, and UCB. Dr Trigoni has reported relationships with AbbVie, UCB, Novartis, and LEO. Dr Trigoni has reported relationships with AbbVie, UCB, Novartis, and LEO. Dr van der Zee has received honoraria from AbbVie. Drs van Straalen, Benhadou, Cuencia-Barrales, Daxhelet, Daoud, Efthymiou, Marzano, Molina-Leyva, Moltrasio, Potenza, Skroza, Stergianou, and Vilarrasa have no conflicts of interest to declare., (Copyright © 2021 American Academy of Dermatology, Inc. Published by Elsevier Inc. All rights reserved.)

Recent publications on the probable role of heparin-binding protein (HBP) as a biomarker in sepsis prompted us to investigate its diagnostic and prognostic performance in severe COVID-19. HBP and IL-6 were measured by immunoassays at admission and on day 7 in 178 patients with pneumonia by SARS-CoV-2. Patients were classified into non-sepsis and sepsis as per the Sepsis-3 definitions and were followed up for the development of severe respiratory failure (SRF) and for outcome. Results were confirmed by multivariate analyses. HBP was significantly higher in patients classified as having sepsis and was negatively associated with the oxygenation ratio and positively associated with creatinine and lactate. Logistic regression analysis evidenced admission HBP more than 18 ng/ml and IL-6 more than 30 pg/ml as independent risk factors for the development of SRP. Their integration prognosticated SRF with respective sensitivity, specificity, positive predictive value, and negative predictive 59.1%, 96.3%, 83.9%, and 87.8%. Cox regression analysis evidenced admission HBP more than 35 ng/ml and IL-6 more than 30 pg/ml as independent risk factors for 28-day mortality. Their integration prognosticated 28-day mortality with respective sensitivity, specificity, positive predictive value, and negative predictive value 69.2%, 92.7%, 42.9%, and 97.5%. HBP remained unchanged over-time course. A prediction score of the disposition of patients with COVID-19 is proposed taking into consideration admission levels of IL-6 and HBP. Using different cut-offs, the score may predict the likelihood for SRF and for 28-day outcome.

Background: Whether or not to administer antibiotics is a common and challenging clinical decision in patients with suspected infections presenting to the emergency department (ED). We prospectively validate InSep, a 29-mRNA blood-based host response test for the prediction of bacterial and viral infections., Methods: The PROMPT trial is a prospective, non-interventional, multi-center clinical study that enrolled 397 adult patients presenting to the ED with signs of acute infection and at least one vital sign change. The infection status was adjudicated using chart review (including a syndromic molecular respiratory panel, procalcitonin and C-reactive protein) by three infectious disease physicians blinded to InSep results. InSep (version BVN-2) was performed using PAXgene Blood RNA processed and quantified on NanoString nCounter SPRINT. InSep results (likelihood of bacterial and viral infection) were compared to the adjudicated infection status., Results: Subject mean age was 64 years, comorbidities were significant for diabetes (17.1%), chronic obstructive pulmonary disease (13.6%), and severe neurological disease (6.8%); 16.9% of subjects were immunocompromised. Infections were adjudicated as bacterial (14.1%), viral (11.3%) and noninfected (0.25%): 74.1% of subjects were adjudicated as indeterminate. InSep distinguished bacterial vs. viral/noninfected patients and viral vs. bacterial/noninfected patients using consensus adjudication with AUROCs of 0.94 (95% CI 0.90-0.99) and 0.90 (95% CI 0.83-0.96), respectively. AUROCs for bacterial vs. viral/noninfected patients were 0.88 (95% CI 0.79-0.96) for PCT, 0.80 (95% CI 0.72-89) for CRP and 0.78 (95% CI 0.69-0.87) for white blood cell counts (of note, the latter biomarkers were provided as part of clinical adjudication). To enable clinical actionability, InSep incorporates score cutoffs to allocate patients into interpretation bands. The Very Likely (rule in) InSep bacterial band showed a specificity of 98% compared to 94% for the corresponding PCT band (> 0.5 µg/L); the Very Unlikely (rule-out) band showed a sensitivity of 95% for InSep compared to 86% for PCT. For the detection of viral infections, InSep demonstrated a specificity of 93% for the Very Likely band (rule in) and a sensitivity of 96% for the Very Unlikely band (rule out)., Conclusions: InSep demonstrated high accuracy for predicting the presence of both bacterial and viral infections in ED patients with suspected acute infections or suspected sepsis. When translated into a rapid, point-of-care test, InSep will provide ED physicians with actionable results supporting early informed treatment decisions to improve patient outcomes while upholding antimicrobial stewardship. Registration number at Clinicaltrials.gov NCT03295825.

Context: Lymphopenia is a key feature of immune dysfunction in patients with bacterial sepsis and coronavirus disease 2019 (COVID-19) and is associated with poor clinical outcomes, but the cause is largely unknown. Severely ill patients may present with thyroid function abnormalities, so-called nonthyroidal illness syndrome, and several studies have linked thyrotropin (thyroid stimulating hormone, TSH) and the thyroid hormones thyroxine (T4) and 3,5,3'-triiodothyronine (T3) to homeostatic regulation and function of lymphocyte populations., Objective: This work aimed to test the hypothesis that abnormal thyroid function correlates with lymphopenia in patients with severe infections., Methods: A retrospective analysis of absolute lymphocyte counts, circulating TSH, T4, free T4 (FT4), T3, albumin, and inflammatory biomarkers was performed in 2 independent hospitalized study populations: bacterial sepsis (n = 224) and COVID-19 patients (n = 161). A subgroup analysis was performed in patients with severe lymphopenia and normal lymphocyte counts., Results: Only T3 significantly correlated (ρ = 0.252) with lymphocyte counts in patients with bacterial sepsis, and lower concentrations were found in severe lymphopenic compared to nonlymphopenic patients (n = 56 per group). Severe lymphopenic COVID-19 patients (n = 17) showed significantly lower plasma concentrations of TSH, T4, FT4, and T3 compared to patients without lymphopenia (n = 18), and demonstrated significantly increased values of the inflammatory markers interleukin-6, C-reactive protein, and ferritin. Remarkably, after 1 week of follow-up, the majority (12 of 15) of COVID-19 patients showed quantitative recovery of their lymphocyte numbers, whereas TSH and thyroid hormones remained mainly disturbed., Conclusion: Abnormal thyroid function correlates with lymphopenia in patients with severe infections, like bacterial sepsis and COVID-19, but future studies need to establish whether a causal relationship is involved., (© The Author(s) 2021. Published by Oxford University Press on behalf of the Endocrine Society. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Aims Infection by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) may lead to the development of severe respiratory failure. In hospitalized-patients, prompt interruption of the virus-driven inflammatory process by using combination treatments seems theoretically of outmost importance. Our aim was to investigate the hypothesis of multifaceted management of these patients. Methods A treatment algorithm based on ferritin was applied in 311 patients (67.2% males; median age 63-years; moderate disease, n=101; severe, n=210). Patients with ferritin <500ng/ml received anakinra 2-4mg/kg/day ± corticosteroids (Arm A, n=142) while those with ≥500ng/ml received anakinra 5-8mg/kg/day with corticosteroids and γ-globulins (Arm B, n=169). In case of no improvement a single dose of tocilizumab (8mg/kg; maximum 800mg) was administered with the potential of additional second and/or third pulses. Treatment endpoints were the rate of the development of respiratory failure necessitating intubation and the SARS-CoV-2-related mortality. The proposed algorithm was also validated in matched hospitalized-patients treated with standard-of-care during the same period. Results In overall, intubation and mortality rates were 5.8% and 5.1% (0% in moderate; 8.6% and 7.6% in severe). Low baseline pO 2 /FiO 2 and older age were independent risk factors. Comparators had significantly higher intubation (HR=7.4; 95%CI: 4.1-13.4; p<0.001) and death rates (HR=4.5, 95%CI: 2.1-9.4, p<0.001). Significant adverse events were rare, including severe secondary infections in only 7/311 (2.3%). Conclusions Early administration of personalized combinations of immunomodulatory agents may be life-saving in hospitalized-patients with COVID-19. An immediate intervention (the sooner the better) could be helpful to avoid development of full-blown acute respiratory distress syndrome and improve survival., (Copyright © 2021. Published by Elsevier B.V.)

The zoonotic SARS-CoV-2 virus that causes COVID-19 continues to spread worldwide, with devastating consequences. While the medical community has gained insight into the epidemiology of COVID-19, important questions remain about the clinical complexities and underlying mechanisms of disease phenotypes. Severe COVID-19 most commonly involves respiratory manifestations, although other systems are also affected, and acute disease is often followed by protracted complications. Such complex manifestations suggest that SARS-CoV-2 dysregulates the host response, triggering wide-ranging immuno-inflammatory, thrombotic, and parenchymal derangements. We review the intricacies of COVID-19 pathophysiology, its various phenotypes, and the anti-SARS-CoV-2 host response at the humoral and cellular levels. Some similarities exist between COVID-19 and respiratory failure of other origins, but evidence for many distinctive mechanistic features indicates that COVID-19 constitutes a new disease entity, with emerging data suggesting involvement of an endotheliopathy-centred pathophysiology. Further research, combining basic and clinical studies, is needed to advance understanding of pathophysiological mechanisms and to characterise immuno-inflammatory derangements across the range of phenotypes to enable optimum care for patients with COVID-19., Competing Interests: Declaration of interests MSW has received unrestricted funding from Sartorius. GL reports personal fees from Swedish Orphan Biovitrum. TSp and JCS disclose institutional funding (received by the University of Bern) from Orion Pharma, Abbott Nutrition International, B Braun Medical, CSEM, Edwards Lifesciences, Kenta Biotech, Maquet Critical Care, Omnicare Clinical Research, Nestlé, Pierre Fabre Pharma, Pfizer, Bard Medica, Abbott, Anandic Medical Systems, PanGas Healthcare, Bracco, Hamilton Medical, Fresenius Kabi, Getinge Group Maquet, Dräger, Teleflex Medical, GlaxoSmithKline, Merck Sharp and Dohme, Eli Lilly, Baxter, Astellas, AstraZeneca, CSL Behring, Novartis, Covidien, Nycomed, Phagenesis, and Hemotune. MGN reports grants from GlaxoSmithKline and ViiV Healthcare, and was a scientific founder of TTxD. All other authors declare no competing interests., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

The reported incidence of COVID-19 among cohorts of patients with inflammatory bowel and skin diseases under treatment with biologicals is low. Treatment may further modify disease severity as some biological modifiers, such as anakinra, are also proposed for the management of COVID-19 patients potentially providing HS patients with an advantage. The above preliminary evidence suggests that hidradenitis suppurativa (HS) does probably not provide an increased susceptibility for COVID-19 and that any susceptibility is unlikely to be modified negatively by treatment with biologicals. On the occasion of its 10th International Conference, experts of the European Hidradenitis Suppurativa Foundation e.V. have prepared a consensus statement regarding anti-COVID-19 measurements for HS patients. Based on the available knowledge, patients with HS may be vaccinated against SARS-CoV2 and patients affected by metabolic syndrome constitute a high-risk group for COVID-19 and should be vaccinated at the earliest convenient point in time. HS patients on treatment with adalimumab can be vaccinated with non-living virus anti-SARS-CoV2 vaccines. A possible suboptimal effect of the vaccine may be suspected but might not be expected universally. The management of the biological treatment in HS patients is at the discretion of the dermatologist / responsible physician., (© 2021 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

The registration of the tumour necrosis factor-α inhibitor adalimumab in 2015 was a major step forward in the treatment of hidradenitis suppurativa/acne inversa (HS). However, it soon became evident that the effectiveness of adalimumab in daily practice was highly variable. A significant unmet medical need of HS patients remained, and the search for novel therapeutic targets was intensified. During the 10th European Hidradenitis Suppurativa Foundation (EHSF) e.V. Conference, reknown international HS investigators virtually presented and discussed the published data on these potential target molecules for future HS treatment. This article addresses the most promising molecules currently under investigation from a pathophysiological and clinical point of view. With phase III trials ongoing, the anti- interleukin (IL)-17 biologics bimekizumab and secukinumab are in the most advanced stage of clinical development showing promising results. In addition, targeting IL-1α with bermekimab has shown encouraging results in two clinical trials. Directing treatment at neutrophil recruitment and activation by targeting IL-36 with spesolimab fits well in the pathogenic concept of HS and clinical phase II trial results are pending. In contrast to in situ evidence, Complement 5a (C5a) and C5a receptor blockade have only shown greater clinical benefit in patients with severe HS. Inhibition of Janus kinase (JAK) 1 signalling in HS showed clinical efficacy only in the highest dosage, highlighting that careful surveillance of the balance between safety and efficacy of JAK inhibition is warranted. Overall, clinical efficacies of all novel treatments reported so far are modest. To guide drug development, more and better-defined translational data on the pathogenesis of this severe and enigmatic inflammatory skin disease are required., (© 2021 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Fast and reliable detection of patients with severe and heterogeneous illnesses is a major goal of precision medicine 1,2 . Patients with leukaemia can be identified using machine learning on the basis of their blood transcriptomes 3 . However, there is an increasing divide between what is technically possible and what is allowed, because of privacy legislation 4,5 . Here, to facilitate the integration of any medical data from any data owner worldwide without violating privacy laws, we introduce Swarm Learning-a decentralized machine-learning approach that unites edge computing, blockchain-based peer-to-peer networking and coordination while maintaining confidentiality without the need for a central coordinator, thereby going beyond federated learning. To illustrate the feasibility of using Swarm Learning to develop disease classifiers using distributed data, we chose four use cases of heterogeneous diseases (COVID-19, tuberculosis, leukaemia and lung pathologies). With more than 16,400 blood transcriptomes derived from 127 clinical studies with non-uniform distributions of cases and controls and substantial study biases, as well as more than 95,000 chest X-ray images, we show that Swarm Learning classifiers outperform those developed at individual sites. In addition, Swarm Learning completely fulfils local confidentiality regulations by design. We believe that this approach will notably accelerate the introduction of precision medicine.

Objectives: Leukocytes are first responders to infection. Their activation state can reveal information about specific host immune response and identify dysregulation in sepsis. This study aims to use the Raman spectroscopic fingerprints of blood-derived leukocytes to differentiate inflammation, infection, and sepsis in hospitalized patients. Diagnostic sensitivity and specificity shall demonstrate the added value of the direct characterization of leukocyte's phenotype., Design: Prospective nonrandomized, single-center, observational phase-II study (DRKS00006265)., Setting: Jena University Hospital, Germany., Patients: Sixty-one hospitalized patients (19 with sterile inflammation, 23 with infection without organ dysfunction, 18 with sepsis according to Sepsis-3 definition)., Interventions: None (blood withdrawal)., Measurements and Main Results: Individual peripheral blood leukocytes were characterized by Raman spectroscopy. Reference diagnostics included established clinical scores, blood count, and biomarkers (C-reactive protein, procalcitonin and interleukin-6). Binary classification models using Raman data were able to distinguish patients with infection from patients without infection, as well as sepsis patients from patients without sepsis, with accuracies achieved with established biomarkers. Compared with biomarker information alone, an increase of 10% (to 93%) accuracy for the detection of infection and an increase of 18% (to 92%) for detection of sepsis were reached by adding the Raman information. Leukocytes from sepsis patients showed different Raman spectral features in comparison to the patients with infection that point to the special immune phenotype of sepsis patients., Conclusions: Raman spectroscopy can extract information on leukocyte's activation state in a nondestructive, label-free manner to differentiate sterile inflammation, infection, and sepsis., Competing Interests: The authors have disclosed that they do not have any potential conflicts of interest., (Copyright © 2021 The Authors. Published by Wolters Kluwer Health, Inc. on behalf of the Society of Critical Care Medicine.)

Lipopolysaccharide (LPS) and monophosphoryl lipid A (MPLA) induce, overall, similar transcriptional profiles in healthy individuals, although LPS has been shown to more potently induce pro-inflammatory cytokines. We explore herein whether MPLA could be considered as a synthetic replacement of LPS in immune functional assays to study anergy of immune cells in septic patients. Ex vivo whole blood stimulation with MPLA revealed a lower induction of the TNFα secreted protein in 20 septic patients (SP) compared to 10 healthy volunteers (HV), in agreement with monocyte anergy. Principal component analysis of the 93-gene molecular response to MPLA and LPS stimulation found that the main variability was driven by stimulation in HV and by pathophysiology in SP. MPLA was a stronger inducer of the HLA family genes than LPS in both populations, arguing for divergent signalling pathways downstream of TLR-4. In addition, MPLA appeared to present a more informative stratification potential within the septic population., (Copyright © 2021 The Authors. Published by Elsevier Inc. All rights reserved.)

Background: Although the ability of β-D-glucan and monophosphoryl lipid A (MPLA) to modulate immune responses has been studied in human primary cells, their effect on sterile inflammation models such as necrotizing pancreatitis has never been investigated., Materials and Methods: 85 male New Zealand rabbits were assigned into following groups: A: control, B: pretreatment with β-D-glucan 3 d before pancreatitis, C: pretreatment with MPLA 3 d before pancreatitis, D: pretreatment with β-D-glucan and laminarin 3 d before pancreatitis, E: treatment with β-D-glucan 1 d after pancreatitis, and F: MPLA 1 d after pancreatitis. Pancreatitis was induced by sodium taurocholate injection into the pancreatic duct and parenchyma. Survival was recorded for 21 d. On days 1, 3, and 7, blood was collected for amylase measurement. Peripheral blood mononuclear cells were isolated and stimulated for tumor necrosis factor alpha and interleukin 10 production. Pancreatic necrosis and tissue bacterial load were assessed., Results: 21-d survival was prolonged after pretreatment or treatment with β-D-glucan; this benefit was lost with laminarin administration. At sacrifice, pancreatic inflammatory alterations were more prominent in the control group. Bacterial load was lower after pretreatment or treatment with β-D-glucan and MPLA. Tumor necrosis factor alpha production from stimulated peripheral blood mononuclear cells was significantly decreased, whereas interleukin 10 production remained unaltered after pretreatment or treatment with β-D- glucan., Conclusions: β-D-glucan reduces mortality of experimental pancreatitis in vivo. This is mediated through attenuation of cytokine production and prevention of bacterial translocation., (Copyright © 2020 Elsevier Inc. All rights reserved.)

The clinical spectrum of COVID-19 varies and the differences in host response characterizing this variation have not been fully elucidated. COVID-19 disease severity correlates with an excessive proinflammatory immune response and profound lymphopenia. Inflammatory responses according to disease severity were explored by plasma cytokine measurements and proteomics analysis in 147 COVID-19 patients. Furthermore, peripheral blood mononuclear cell cytokine production assays and whole blood flow cytometry were performed. Results confirm a hyperinflammatory innate immune state, while highlighting hepatocyte growth factor and stem cell factor as potential biomarkers for disease severity. Clustering analysis revealed no specific inflammatory endotypes in COVID-19 patients. Functional assays revealed abrogated adaptive cytokine production (interferon-γ, interleukin-17, and interleukin-22) and prominent T-cell exhaustion in critically ill patients, whereas innate immune responses were intact or hyperresponsive. Collectively, this extensive analysis provides a comprehensive insight into the pathobiology of severe to critical COVID-19 and highlights potential biomarkers of disease severity., (© The Author(s) 2021. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail: journals.permissions@oup.com.)

Viral infections induce a conserved host response distinct from bacterial infections. We hypothesized that the conserved response is associated with disease severity and is distinct between patients with different outcomes. To test this, we integrated 4,780 blood transcriptome profiles from patients aged 0 to 90 years infected with one of 16 viruses, including SARS-CoV-2, Ebola, chikungunya, and influenza, across 34 cohorts from 18 countries, and single-cell RNA sequencing profiles of 702,970 immune cells from 289 samples across three cohorts. Severe viral infection was associated with increased hematopoiesis, myelopoiesis, and myeloid-derived suppressor cells. We identified protective and detrimental gene modules that defined distinct trajectories associated with mild versus severe outcomes. The interferon response was decoupled from the protective host response in patients with severe outcomes. These findings were consistent, irrespective of age and virus, and provide insights to accelerate the development of diagnostics and host-directed therapies to improve global pandemic preparedness., Competing Interests: Declaration of interests E.J.G.B. has received honoraria from Abbott CH, Angelini Italy, bioMérieux Inc, InflaRx GmbH, MSD Greece, and XBiotech Inc.; independent educational grants from AbbVie, Abbott, Astellas Pharma Europe, AxisShield, bioMérieux Inc, InflaRx GmbH, ThermoFisher Brahms GmbH, and XBiotech Inc; and funding from the FrameWork 7 program HemoSpec (granted to the National and Kapodistrian University of Athens), the Horizon2020 Marie-Curie Project European Sepsis Academy (granted to the National and Kapodistrian University of Athens), and the Horizon 2020 European Grant ImmunoSep (granted to the Hellenic Institute for the Study of Sepsis). P.K. is a shareholder and a consultant to Inflammatix, Inc. Y.H.B. and Y.D.H. are employees of, and stockholders in, Inflammatix, Inc., (Copyright © 2021 The Author(s). Published by Elsevier Inc. All rights reserved.)

Purpose of Review: Biomarkers, mainly procalcitonin, are commonly used in sepsis diagnosis, prognosis and treatment follow-up. This review summarizes the potential benefit of their use for the critically ill., Recent Findings: Increased clinical evidence from randomized clinical trials of biomarker-guided treatment suggests a trend for appropriate but short antimicrobial treatment for the critically ill. Procalcitonin (PCT) is the most studied biomarker; in the majority of randomized clinical trials, the use of a stopping rule of antibiotics on the day when PCT is below 80% from baseline or less than 0.5 ng/ml was proven effective to reduce length of antimicrobial treatment, antibiotic-associated adverse events and infectious complications like infections by multidrug-resistant organisms and Clostridium difficile. Survival benefit was also noted., Summary: Biomarkers, mainly PCT, may help improve sepsis outcome by restriction of injudicious antimicrobial use., (Copyright © 2021 Wolters Kluwer Health, Inc. All rights reserved.)

Many milestones in medical history rest on animal modeling of human diseases. The SARS-CoV-2 pandemic has evoked a tremendous investigative effort primarily centered on clinical studies. However, several animal SARS-CoV-2/COVID-19 models have been developed and pre-clinical findings aimed at supporting clinical evidence rapidly emerge. In this review, we characterize the existing animal models exposing their relevance and limitations as well as outline their utility in COVID-19 drug and vaccine development. Concurrently, we summarize the status of clinical trial research and discuss the novel tactics utilized in the largest multi-center trials aiming to accelerate generation of reliable results that may subsequently shape COVID-19 clinical treatment practices. We also highlight areas of improvement for animal studies in order to elevate their translational utility. In pandemics, to optimize the use of strained resources in a short time-frame, optimizing and strengthening the synergy between the preclinical and clinical domains is pivotal., Competing Interests: Declaration of Competing Interest The authors declare no conflicts of interest., (Copyright © 2021 The Authors. Published by Elsevier B.V. All rights reserved.)

Hydrogen sulfide (H2S) has recently been recognized as a novel gaseous transmitter with several anti-inflammatory properties. The role of host- derived H2S in infections by Pseudomonas aeruginosa was investigated in clinical and mouse models. H2S concentrations and survival was assessed in septic patients with lung infection. Animal experiments using a model of severe systemic multidrug-resistant P. aeruginosa infection were performed using mice with a constitutive knock-out of cystathionine-γ lyase (Cse) gene (Cse-/-) and wild-type mice with a physiological expression (Cse+/+). Experiments were repeated in mice after a) treatment with cyclophosphamide; b) bone marrow transplantation (BMT) from a Cse+/+ donor; c) treatment with H2S synthesis inhibitor aminooxyacetic acid (ΑΟΑΑ) or propargylglycine (PAG) and d) H2S donor sodium thiosulfate (STS) or GYY3147. Bacterial loads and myeloperoxidase activity were measured in tissue samples. The expression of quorum sensing genes (QS) was determined in vivo and in vitro. Cytokine concentration was measured in serum and incubated splenocytes. Patients survivors at day 28 had significantly higher serum H2S compared to non-survivors. A cut- off point of 5.3 μΜ discriminated survivors with sensitivity 92.3%. Mortality after 28 days was 30.9% and 93.7% in patients with H2S higher and less than 5.3 μΜ (p = 7 x 10-6). In mice expression of Cse and application of STS afforded protection against infection with multidrug-resistant P. aeruginosa. Cyclophosphamide pretreatment eliminated the survival benefit of Cse+/+ mice, whereas BMT increased the survival of Cse-/- mice. Cse-/- mice had increased pathogen loads compared to Cse+/+ mice. Phagocytic activity of leukocytes from Cse-/- mice was reduced but was restored after H2S supplementation. An H2S dependent down- regulation of quorum sensing genes of P.aeruginosa could be demonstrated in vivo and in vitro. Endogenous H2S is a potential independent parameter correlating with the outcome of P. aeruginosa. H2S provides resistance to infection by MDR bacterial pathogens., Competing Interests: The authors have declared that no competing interests exist.

Large clinical trials testing hydrocortisone therapy in septic shock have produced conflicting results. Subgroups may benefit of hydrocortisone treatment depending on their individual immune response. We performed an exploratory analysis of the database from the international randomized controlled clinical trial Corticosteroid Therapy of Septic Shock (CORTICUS) employing machine learning to a panel of 137 variables collected from the Berlin subcohort comprising 83 patients including demographic and clinical measures, organ failure scores, leukocyte counts and levels of circulating cytokines. The identified theranostic marker was validated against data from a cohort of the Hellenic Sepsis Study Group (HSSG) ( n = 246), patients enrolled in the clinical trial of Sodium Selenite and Procalcitonin Guided Antimicrobial Therapy in Severe Sepsis (SISPCT, n = 118), and another, smaller clinical trial (Crossover study, n = 20). In addition, in vitro blood culture experiments and in vivo experiments in mouse models were performed to assess biological plausibility. A low serum IFNγ/IL10 ratio predicted increased survival in the hydrocortisone group whereas a high ratio predicted better survival in the placebo group. Using this marker for a decision rule, we applied it to three validation sets and observed the same trend. Experimental studies in vitro revealed that IFNγ/IL10 was negatively associated with the load of (heat inactivated) pathogens in spiked human blood and in septic mouse models. Accordingly, an in silico analysis of published IFNγ and IL10 values in bacteremic and non-bacteremic patients with the Systemic Inflammatory Response Syndrome supported this association between the ratio and pathogen burden. We propose IFNγ/IL10 as a molecular marker supporting the decision to administer hydrocortisone to patients in septic shock. Prospective clinical studies are necessary and standard operating procedures need to be implemented, particularly to define a generic threshold. If confirmed, IFNγ/IL10 may become a suitable theranostic marker for an urging clinical need., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 König, Kolte, Ahlers, Oswald, Krauss, Roell, Sommerfeld, Dimopoulos, Tsangaris, Antoniadou, Jaishankar, Bogatsch, Löffler, Rödel, Garcia-Moreno, Tuchscherr, Sprung, Singer, Brunkhorst, Oppert, Gerlach, Claus, Coldewey, Briegel, Giamarellos-Bourboulis, Keh and Bauer.)

Background: It was studied if early suPAR-guided anakinra treatment can prevent severe respiratory failure (SRF) of COVID-19., Methods: A total of 130 patients with suPAR ≥6 ng/ml were assigned to subcutaneous anakinra 100 mg once daily for 10 days. Primary outcome was SRF incidence by day 14 defined as any respiratory ratio below 150 mmHg necessitating mechanical or non-invasive ventilation. Main secondary outcomes were 30-day mortality and inflammatory mediators; 28-day WHO-CPS was explored. Propensity-matched standard-of care comparators were studied., Results: 22.3% with anakinra treatment and 59.2% comparators (hazard ratio, 0.30; 95% CI, 0.20-0.46) progressed into SRF; 30-day mortality was 11.5% and 22.3% respectively (hazard ratio 0.49; 95% CI 0.25-0.97). Anakinra was associated with decrease in circulating interleukin (IL)-6, sCD163 and sIL2-R; IL-10/IL-6 ratio on day 7 was inversely associated with SOFA score; patients were allocated to less severe WHO-CPS strata., Conclusions: Early suPAR-guided anakinra decreased SRF and restored the pro-/anti-inflammatory balance., Funding: This study was funded by the Hellenic Institute for the Study of Sepsis, Technomar Shipping Inc, Swedish Orphan Biovitrum, and the Horizon 2020 Framework Programme., Clinical Trial Number: NCT04357366., Competing Interests: EK, SM, NG, EK, MS, GL, AS, DP, SG, OT, VP, KT, MK, VL, MD, IP, KA, DM, AG, AS, TG, KK, TM, IT, KS, LC, SC, NV, CA, SC, MK No competing interests declared, PP honoraria from GILEAD Sciences, Janssen, and MSD, GD Advisor/Lecturer for Abbvie, Bristol-Myers Squibb, Gilead, Novartis, Roche, Amgen, MSD, Janssen, Ipsen and Pfizer, has received Grant support from Bristol-Myers Squib, Gilead, Roche, Janssen, Abbvie and Bayer and was or is currently PI in National & International Protocols sponsored by Abbvie, Bristol-Myers Squibb, Novartis, Gilead, Novo Nordisk, Genkyotex, Regulus Therapeutics Inc, Tiziana Life Sciences, Bayer, Astellas, Ipsen, Pfizer and Roche, GP independent educational grants from Pfizer, MSD, Angelini, and Biorad, HM honoraria, consulting fees and non-financial support from healthcare companies, including Amgen, Angelini, Bayer, Mylan, MSD, Pfizer, and Servier, Jv Senior editor, eLife, JE cofounder, shareholder and CSO of ViroGates A7S, Denmark and is named inventor on patents on suPAR owned by Copenhagen University Hospital Hvidovre, Denmark, MN supported by an ERC Advanced Grant (#833247) and a Spinoza grant of the Netherlands Organization for Scientific Research. He has also received independent educational grants from TTxD, GSK and ViiV HealthCare, EG Reviewing editor, eLife, (© 2021, Kyriazopoulou et al.)

Background: Excessive activation of immune responses in coronavirus disease 2019 (COVID-19) is considered to be related to disease severity, complications, and mortality rate. The complement system is an important component of innate immunity and can stimulate inflammation, but its role in COVID-19 is unknown., Methods: A prospective, longitudinal, single center study was performed in hospitalized patients with COVID-19. Plasma concentrations of complement factors C3a, C3c, and terminal complement complex (TCC) were assessed at baseline and during hospital admission. In parallel, routine laboratory and clinical parameters were collected from medical files and analyzed., Results: Complement factors C3a, C3c, and TCC were significantly increased in plasma of patients with COVID-19 compared with healthy controls (P < .05). These complement factors were especially elevated in intensive care unit patients during the entire disease course (P < .005 for C3a and TCC). More intense complement activation was observed in patients who died and in those with thromboembolic events., Conclusions: Patients with COVID-19 demonstrate activation of the complement system, which is related to disease severity. This pathway may be involved in the dysregulated proinflammatory response associated with increased mortality rate and thromboembolic complications. Components of the complement system might have potential as prognostic markers for disease severity and as therapeutic targets in COVID-19., (© The Author(s) 2020. Published by Oxford University Press for the Infectious Diseases Society of America.)

Objectives: Complex critical syndromes like sepsis and coronavirus disease 2019 may be composed of underling "endotypes," which may respond differently to treatment. The aim of this study was to test whether a previously defined bacterial sepsis endotypes classifier recapitulates the same clinical and immunological endotypes in coronavirus disease 2019., Design: Prospective single-center observational cohort study., Setting: Patients were enrolled in Athens, Greece, and blood was shipped to Inflammatix (Burlingame, CA) for analysis., Patients: Adult patients within 24 hours of hospital admission with coronavirus disease 2019 confirmed by polymerase chain reaction and chest radiography., Interventions: None., Measurements and Main Results: We studied 97 patients with coronavirus disease 2019, of which 50 went on to severe respiratory failure (SRF) and 16 died. We applied a previously defined 33-messenger RNA classifier to assign endotype (Inflammopathic, Adaptive, or Coagulopathic) to each patient. We tested endotype status against other clinical parameters including laboratory values, severity scores, and outcomes. Patients were assigned as Inflammopathic (29%), Adaptive (44%), or Coagulopathic (27%), similar to our prior study in bacterial sepsis. Adaptive patients had lower rates of SRF and no deaths. Coagulopathic and Inflammopathic endotypes had 42% and 18% mortality rates, respectively. The Coagulopathic group showed highest d-dimers, and the Inflammopathic group showed highest C-reactive protein and interleukin-6 levels., Conclusions: Our predefined 33-messenger RNA endotypes classifier recapitulated immune phenotypes in viral sepsis (coronavirus disease 2019) despite its prior training and validation only in bacterial sepsis. Further work should focus on continued validation of the endotypes and their interaction with immunomodulatory therapy., Competing Interests: Drs. Sweeney, Liesenfeld, Wacker, He, Rawling, and Midic received funding from Inflammatix. Drs. He and Kontogeorgou disclosed work for hire. Dr. Sweeney, Dr. Liesenfeld, Dr. Wacker, Dr. He, Dr. Rawling, Ms. Coyle, Dr. Midic are employees of, and stockholders in, Inflammatix, which has exclusive license to the patent covering the 33-messenger RNA set. Dr. Giamarellos-Bourboulis has received honoraria from AbbVie USA, Abbott CH, InflaRx GmbH, MSD Greece, XBiotech, and Angelini Italy; independent educational grants from AbbVie, Abbott, Astellas Pharma Europe, AxisShield, bioMérieux, InflaRx GmbH, and XBiotech; and funding from the FrameWork 7 program HemoSpec (granted to the National and Kapodistrian University of Athens), the Horizon2020 Marie-Curie Project European Sepsis Academy (granted to the National and Kapodistrian University of Athens), and the Horizon 2020 European Grant ImmunoSep (granted to the Hellenic Institute for the Study of Sepsis). The remaining authors have disclosed that they do not have any potential conflicts of interest., (Copyright © 2020 by the Society of Critical Care Medicine and Wolters Kluwer Health, Inc. All Rights Reserved.)

Rationale: Although early antimicrobial discontinuation guided by procalcitonin (PCT) has shown decreased antibiotic consumption in lower respiratory tract infections, the outcomes in long-term sepsis sequelae remain unclear. Objectives: To investigate if PCT guidance may reduce the incidence of long-term infection-associated adverse events in sepsis. Methods: In this multicenter trial, 266 patients with sepsis (by Sepsis-3 definitions) with lower respiratory tract infections, acute pyelonephritis, or primary bloodstream infection were randomized (1:1) to receive either PCT-guided discontinuation of antimicrobials or standard of care. The discontinuation criterion was ≥80% reduction in PCT levels or any PCT ≤0.5 μg/L at Day 5 or later. The primary outcome was the rate of infection-associated adverse events at Day 180, a composite of the incidence of any new infection by Clostridioides difficile or multidrug-resistant organisms, or any death attributed to baseline C. difficile or multidrug-resistant organism infection. Secondary outcomes included 28-day mortality, length of antibiotic therapy, and cost of hospitalization. Measurements and Main Results: The rate of infection-associated adverse events was 7.2% (95% confidence interval [CI], 3.8-13.1%; 9/125) versus 15.3% (95% CI, 10.1-22.4%; 20/131) (hazard ratio, 0.45; 95% CI, 0.20-0.98; P  = 0.045); 28-day mortality 15.2% (95% CI, 10-22.5%; 19/125) versus 28.2% (95% CI, 21.2-36.5%; 37/131) (hazard ratio, 0.51; 95% CI, 0.29-0.89; P  = 0.02); and median length of antibiotic therapy 5 (range, 5-7) versus 10 (range, 7-15) days ( P  < 0.001) in the PCT and standard-of-care arms, respectively. The cost of hospitalization was also reduced in the PCT arm. Conclusions: In sepsis, PCT guidance was effective in reducing infection-associated adverse events, 28-day mortality, and cost of hospitalization.Clinical trial registered with www.clinicaltrials.gov (NCT03333304).