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Background: Numerous, mostly uncontrolled, observations suggest that artificial liver support with the Molecular Adsorbent Recirculating System (MARS) improves pathophysiologic sequelae and outcome of acute and acute-on-chronic liver failure. MARS is felt to be safe, but extracorporeal circuits may activate coagulation. Objective: To assess the frequency of and risk factors for activation of coagulation during MARS treatment. Patients/Methods: Retrospective analysis of coagulopathy/bleeding complications observed during 83 consecutive MARS sessions in 21 patients (11 men; median age 46 years; median three sessions per patient; median duration of session 8 h). Results: Nine clinically relevant episodes of coagulopathy/bleeding were observed in eight patients, forced to premature cessation of MARS in seven and ended lethal in four. Four complications occurred during the first, five during later (third to seventh) MARS sessions and two bleeders tolerated further sessions without complications. Coagulation parameters worsened significantly also during MARS sessions not associated with bleeding ( P≤0.004). In univariate analysis, patient's age, vasopressor therapy, pretreatment INR, fibrin D–dimer and fibrinogen concentrations, but not severity of underlying disease (MELD, Child-Pugh, SAPS II scores), were significantly associated with coagulopathy ( P<0.05). Only patient's age, fibrin D-dimer level and INR were retained in a multivariate model correctly classifying 98% of sessions without, but only 33% with complications. Conclusion: Coagulation is frequently activated during MARS therapy, potentially leading to bleeding complications and mortality. [ABSTRACT FROM AUTHOR]

Activated protein C (APC) has endothelial barrier protective effects that require binding to endothelial protein C receptor (EPCR) and cleavage of protease activated receptor-1 (PAR1) and that may play a role in the anti-inflammatory action of APC. In this study we investigated whether protein C (PC) activation by thrombin on the endothelial cell surface may be linked to efficient protective signaling. To minimize direct thrombin effects on endothelial permeability we used the anticoagulant double mutant thrombin VC215A/E217A (WE). Activation of PC by WE on the endothelial cell surface generated APC with high barrier protective activity. Comparable barrier protective effects by exogenous APC required a 4-fold higher concentration of APC. To demonstrate conclusively that protective effects in the presence of WE are mediated by APC generation and not direct signaling by WE, we used a PC variant with a substitution of the active site serine with alanine (PC S360A). Barrier protective effects of a low concentration of exogenous APC were blocked by both wildtype PC and PC S360A, consistent with their expected role as competitive inhibitors for APC binding to EPCR. WE induced protective signaling only in the presence of wild type PC but not PC S360A and PAR1 cleavage was required for these protective effects. These data demonstrate that the endogenous PC activation pathway on the endothelial cell surface is mechanistically linked to PAR1-dependent autocrine barrier protective signaling by the generated APC. WE may have powerful protective effects in systemic inflammation through signaling by the endogenously generated APC. [ABSTRACT FROM AUTHOR]

Following the publication of this article [1], the authors reported an incorrect citation in the following sentence in the "Metalloproteases" sub-section: [ABSTRACT FROM AUTHOR]

Background: The continuous exposure of blood to a non-biological surface during extracorporeal membrane oxygenation (ECMO) may lead to progressive thrombus formation in the oxygenator, hemolysis and consequently impaired gas exchange. In most centers oxygenator performance is monitored only on a once daily basis. Carboxyhemoglobin (COHb) is generated upon red cell lysis and is routinely measured with any co-oximetry performed to surveille gas exchange and acid–base homeostasis every couple of hours. This retrospective cohort study aims to evaluate COHb in the arterial blood gas as a novel marker of oxygenator dysfunction and its predictive value for imminent oxygenator change. Results: Out of the 484 screened patients on ECMO 89, cumulatively requiring 116 oxygenator changes within 1833 patient days, including 19,692 arterial COHb measurements were analyzed. Higher COHb levels were associated with lower post-oxygenator pO2 (estimate for log(COHb): − 2.176 [95% CI − 2.927, − 1.427], p < 0.0001) and with a shorter time to oxygenator change (estimate for log(COHb): − 67.895 [95% CI − 74.209, − 61.542] hours, p < 0.0001). COHb was predictive of oxygenator change within 6 h (estimate for log(COHb): 5.027 [95% CI 1.670, 15.126], p = 0.004). Conclusion: COHb correlates with oxygenator performance and can be predictive of imminent oxygenator change. Therefore, longitudinal measurements of COHb in clinical routine might be a cheap and more granular candidate for ECMO surveillance that should be further analyzed in a controlled prospective trial design. [ABSTRACT FROM AUTHOR]

Background: This study aimed to assess a potential organ protective effect of volatile sedation in a scenario of severe inflammation with an early cytokine storm (in particular IL-6 elevation) in patients suffering from COVID-19-related lung injury with invasive mechanical ventilation and sedation. Methods: This is a small-scale pilot multicenter randomized controlled trial from four tertiary hospitals in Switzerland, conducted between April 2020 and May 2021. 60 patients requiring mechanical ventilation due to severe COVID-19-related lung injury were included and randomized to 48-hour sedation with sevoflurane vs. continuous intravenous sedation (= control) within 24 h after intubation. The primary composite outcome was determined as mortality or persistent organ dysfunction (POD), defined as the need for mechanical ventilation, vasopressors, or renal replacement therapy at day 28. Secondary outcomes were the length of ICU and hospital stay, adverse events, routine laboratory parameters (creatinine, urea), and plasma inflammatory mediators. Results: 28 patients were randomized to sevoflurane, 32 to the control arm. The intention-to-treat analysis revealed no difference in the primary endpoint with 11 (39%) sevoflurane and 13 (41%) control patients (p = 0.916) reaching the primary outcome. Five patients died within 28 days in each group (16% vs. 18%, p = 0.817). Of the 28-day survivors, 6 (26%) and 8 (30%) presented with POD (p = 0.781). There was a significant difference regarding the need for vasopressors (1 (4%) patient in the sevoflurane arm, 7 (26%) in the control one (p = 0.028)). Length of ICU stay, hospital stay, and registered adverse events within 28 days were comparable, except for acute kidney injury (AKI), with 11 (39%) sevoflurane vs. 2 (6%) control patients (p = 0.001). The blood levels of IL-6 in the first few days after the onset of the lung injury were less distinctly elevated than expected. Conclusions: No evident benefits were observed with short sevoflurane sedation on mortality and POD. Unexpectedly low blood levels of IL-6 might indicate a moderate injury with therefore limited improvement options of sevoflurane. Acute renal issues suggest caution in using sevoflurane for sedation in COVID-19. Trial registration: The trial was registered on ClinicalTrials.gov (NCT04355962) on 2020/04/21. [ABSTRACT FROM AUTHOR]

Objectives: Bromelain-based enzymatic debridement has emerged as an alternative to surgical eschar removal. Indications include partial thickness, mixed pattern, and full-thickness burns. Enzymatic debridement has been approved by the European Medicines Agency for treating burn wounds affecting <15% total body surface area (TBSA). Data and evidence for the treatment of areas >15% TBSA in one session is scarce. The aim of this retrospective study was to retrospectively analyze off-label use of enzymatic debridement in a single burn center for large TBSA burns.Methods: Between 01/2017 and 12/2018, 59 patients with partial- to full-thickness burns underwent enzymatic debridement in a single center study. Patients were categorized into two groups: the regular use group with a treated area less than 15% TBSA and the off-label group (OG) with larger TBSA debrided in one session. Treatment was evaluated for systemic inflammatory reaction, bleeding, hemodynamic instability and electrolyte shifts.Results: In total, 49 patients were treated in the regular use group with a median application area of 6% (IQR 2.5-9.5) and 10 patients were treated in the off-label group with a median application area of 18% (IQR 15-19) TBSA. We found no significant differences regarding blood pressure, body temperature or hemodynamic stability during and after enzymatic debridement. No treatment-related serious adverse events were observed in either group. Catecholamine use was similar in both groups. No differences in leukocyte counts, CRP, PCT and lactate prior to application and during the following three days were observed. Sodium, potassium, chloride and phosphate levels did not differ. We found no evidence of an electrolyte shift. Survival was 49 of 49 patients (100%) in the RG and 7 of 10 patients (70%) in the OG (p = 0.004).Conclusion: Enzymatic debridement did not result in any expected or unexpected side effects in the patient groups investigated. These preliminary results indicate the potential safety of bromelain-based enzymatic debridementin the treatment of burns greater than 15% TBSA. [ABSTRACT FROM AUTHOR]

Inflammatory diseases have become increasingly prevalent with industrialization. To address this, numerous anti-inflammatory agents and molecular targets have been considered in clinical trials. Among molecular targets, protease-activated receptors (PARs) are abundantly recognized for their roles in the development of chronic inflammatory diseases. In particular, several inflammatory effects are directly mediated by the sensing of proteolytic activity by PARs. PARs belong to the seven transmembrane domain G protein-coupled receptor family, but are unique in their lack of physiologically soluble ligands. In contrast with classical receptors, PARs are activated by N-terminal proteolytic cleavage. Upon removal of specific N-terminal peptides, the resulting N-termini serve as tethered activation ligands that interact with the extracellular loop 2 domain and initiate receptor signaling. In the classical pathway, activated receptors mediate signaling by recruiting G proteins. However, activation of PARs alternatively lead to the transactivation of and signaling through receptors such as co-localized PARs, ion channels, and toll-like receptors. In this review we consider PARs and their modulators as potential therapeutic agents, and summarize the current understanding of PAR functions from clinical and in vitro studies of PAR-related inflammation. [ABSTRACT FROM AUTHOR]

Background: Clogging is characterized by a progressive impairment of transmembrane patency in renal replacement devices and occurs due to obstruction of pores by unknown molecules. If citrate-based anti-coagulation is used, clogging can manifest as a metabolic alkalosis accompanied by hypernatremia and hypercalcemia, primarily a consequence of Na3Citrate infusion. An increased incidence of clogging has been observed during the COVID-19 pandemic. However, precise factors contributing to the formation remain uncertain. This investigation aimed to analyze its incidence and assessed time-varying trajectories of associated factors in critically ill patients on continuous renal replacement therapy (CRRT). Methods: In this retrospective, single-center data analysis, we evaluated COVID-19 patients undergoing CRRT and admitted to critical care between March 2020 and December 2021. We assessed the proportional incidence of clogging surrogates in the overall population and subgroups based on the specific CRRT devices employed at our institution, including multiFiltrate (Fresenius Medical Care) and Prismaflex System (Baxter). Moderate and severe clogging were defined as Na > 145 or ≥ 150 mmol/l and HCO3− > 28.0 or ≥ 30 mmol/l, respectively, with a total albumin-corrected calcium > 2.54 mmol/l. A mixed effect model was introduced to investigate factors associated with development of clogging. Results: Fifty-three patients with 240 CRRT runs were analyzed. Moderate and severe clogging occurred in 15% (8/53) and 19% (10/53) of patients, respectively. Twenty-seven percent (37/136) of CRRTs conducted with a multiFiltrate device met the criteria for clogging, whereas no clogging could be observed in patients dialyzed with the Prismaflex System. Occurrence of clogging was associated with elevated triglyceride plasma levels at filter start (p = 0.013), amount of enteral nutrition (p = 0.002) and an increasing white blood cell count over time (p = 0.002). Conclusions: Clogging seems to be a frequently observed phenomenon in critically ill COVID-19 patients. The presence of hypertriglyceridemia, combined with systemic inflammation, may facilitate the development of an impermeable secondary membrane within filters, thereby contributing to compromised membrane patency. [ABSTRACT FROM AUTHOR]

Bromelain-based enzymatic debridement has emerged as a valuable option to the standard surgical intervention for debridement in burn injuries. Adverse effects on coagulation parameters after enzymatic debridement have been described. The purpose of this study was to compare the effect of enzymatic and surgical debridement on coagulation. Between 03/2017 and 02/2021 patients with burn injuries with a total body surface area (TBSA) ≥ 1% were included in the study. Patients were categorized into two groups: the surgically debrided group and the enzymatically debrided group. Coagulation parameters were assessed daily for the first seven days of hospitalization. In total 132 patients with a mean TBSA of 17% were included in this study, of which 66 received enzymatic debridement and 66 received regular surgical-debridement. Patients receiving enzymatic debridement presented significantly higher factor-V concentration values over the first seven days after admission (p = <0.01). Regarding coagulation parameters, we found no difference in INR-, aPTT-, fibrinogen-, factor-XIII- and thrombocyte-concentrations over the first seven days (p = >0.05). Enzymatic debridement in burned patients does not appear to increase the risk of coagulation abnormalities compared with the regular surgical approach. • Enzymatic debridement (ED) in burned patients does not increase the risk of coagulation. • ED emerges are safe and an alternative to standard treatment without significant effect of the coagulation. • This is the first analysis of coagulation-specific laboratory markers including coagulation factor-V and factor-XIII concentrations in ED. [ABSTRACT FROM AUTHOR]

Background: Optimal anticoagulation strategies for COVID-19 patients with the acute respiratory distress syndrome (ARDS) on venovenous extracorporeal membrane oxygenation (VV ECMO) remain uncertain. A higher incidence of intracerebral hemorrhage (ICH) during VV ECMO support compared to non-COVID-19 viral ARDS patients has been reported, with increased bleeding rates in COVID-19 attributed to both intensified anticoagulation and a disease-specific endotheliopathy. We hypothesized that lower intensity of anticoagulation during VV ECMO would be associated with a lower risk of ICH. In a retrospective, multicenter study from three academic tertiary intensive care units, we included patients with confirmed COVID-19 ARDS requiring VV ECMO support from March 2020 to January 2022. Patients were grouped by anticoagulation exposure into higher intensity, targeting anti-factor Xa activity (anti-Xa) of 0.3–0.4 U/mL, versus lower intensity, targeting anti-Xa 0.15–0.3 U/mL, cohorts. Mean daily doses of unfractionated heparin (UFH) per kg bodyweight and effectively measured daily anti-factor Xa activities were compared between the groups over the first 7 days on ECMO support. The primary outcome was the rate of ICH during VV ECMO support. Results: 141 critically ill COVID-19 patients were included in the study. Patients with lower anticoagulation targets had consistently lower anti-Xa activity values over the first 7 ECMO days (p < 0.001). ICH incidence was lower in patients in the lower anti-Xa group: 4 (8%) vs 32 (34%) events. Accounting for death as a competing event, the adjusted subhazard ratio for the occurrence of ICH was 0.295 (97.5% CI 0.1–0.9, p = 0.044) for the lower anti-Xa compared to the higher anti-Xa group. 90-day ICU survival was higher in patients in the lower anti-Xa group, and ICH was the strongest risk factor associated with mortality (odds ratio [OR] 6.8 [CI 2.1–22.1], p = 0.001). Conclusions: For COVID-19 patients on VV ECMO support anticoagulated with heparin, a lower anticoagulation target was associated with a significant reduction in ICH incidence and increased survival. [ABSTRACT FROM AUTHOR]

Background: Therapeutic plasma exchange (TPE) is frequently performed in critical care settings for heterogenous indications. However, specific intensive care unit (ICU) data regarding TPE indications, patient characteristics and technical details are sparse. Methods: We performed a retrospective, single-center study using data from January 2010 until August 2021 for patients treated with TPE in an ICU setting at the University Hospital Zurich. Data collected included patient characteristics and outcomes, ICU-specific parameters, as well as apheresis-specific technical parameters and complications. Results: We identified n = 105 patients receiving n = 408 TPEs for n = 24 indications during the study period. The most common was thrombotic microangiopathies (TMA) (38%), transplant-associated complications (16.3%) and vasculitis (14%). One-third of indications (35.2%) could not be classified according to ASFA. Anaphylaxis was the most common TPE-related complication (6.7%), while bleeding complications were rare (1%). The median duration of ICU stay was 8 ± 14 days. Ventilator support, renal replacement therapy or vasopressors were required in 59 (56.2%), 26 (24.8%), and 35 (33.3%) patients, respectively, and 6 (5.7%) patients required extracorporeal membrane oxygenation. The overall hospital survival rate was 88.6%. Conclusion: Our study provides valuable real-world data on heterogenous TPE indications for patients in the ICU setting, potentially supporting decision-making. [ABSTRACT FROM AUTHOR]

Background: Sepsis is as a life-threatening organ dysfunction caused by a dysregulated host response to an infection. The mortality of sepsis and particular of septic shock is very high. Treatment mostly focuses on infection control but a specific intervention that targets the underlying pathological host response is lacking to the present time. The investigators hypothesize that early therapeutic plasma exchange (TPE) will dampen the maladaptive host response by removing injurious mediators thereby limiting organ dysfunction and improving survival in patients with septic shock. Although small prospective studies demonstrated rapid hemodynamic stabilization under TPE, no adequately powered randomized clinical trial has investigated hard outcomes. Methods: This is a randomized, prospective, multicenter, open-label, controlled, parallel-group interventional trial to test the adjunctive effect of TPE in patients with early septic shock. Patients with a refractory (defined as norepinephrine (NE) ≥ 0.4 μg/kg/min ≥ 30 min OR NE 0.3 μg/kg/min + vasopressin) and early (shock onset < 24 h) septic shock will be included. The intervention is a standard TPE with donor fresh frozen plasma (1.2 × individual plasma volume) performed within 6 h after randomization and will be compared to a standard of care (SOC) control arm. The primary endpoint is 28 days mortality for which the power analysis revealed a group size of 137 / arm (n = 274) to demonstrate a benefit of 15%. The key secondary objective will be to compare the extent of organ failure indicated by mean SOFA over the first 7 days as well as organ support-free days until day 28 following randomization. Besides numerous biological secondary, safety endpoints such as incidence of bleeding, allergic reactions, transfusion associated lung injury, severe thrombocytopenia, and other severe adverse events will be assessed during the first 7 days. For exploratory scientific analyses, biomaterial will be acquired longitudinally and multiple predefined scientific subprojects are planned. This study is an investigator-initiated trial supported by the German Research Foundation (DFG, DA 1209/7–1), in which 26 different centers in Germany, Switzerland, and Austria will participate over a duration of 33 months. Discussion: This trial has substantial clinical relevance as it evaluates a promising adjunctive treatment option in refractory septic shock patients suffering from an extraordinary high mortality. A positive trial result could change the current standard of care for this septic subgroup. The results of this study will be disseminated through presentations at international congresses, workshops, and peer-reviewed publications. Trial registration: ClinicalTrials.gov NCT05726825, Registered on 14 February 2023. [ABSTRACT FROM AUTHOR]

Hypothermia in severely burned patients is associated with a significant increase in morbidity and mortality. The use of an oesophageal heat exchanger tube (EHT) can improve perioperative body temperatures in severely burned patients. The aim of this study was to investigate the intraoperative warming effect of oesophageal heat transfer in severe burn patients. Single-centre retrospective study performed at the Burns Centre of the University Hospital Zurich. Between January 2020 and May 2021 perioperative temperature management with EHT was explored in burned patients with a total body surface area (TBSA) larger than 30%. Data from patients, who received perioperative temperature management by EHT, were compared to data from the same patients during interventions performed under standard temperature management matching for length and type of intervention. A total of 30 interventions (15 with and 15 without EHT) in 10 patients were analysed. Patient were 38 [26−48] years of age, presented with severe burns covering a median of 50 [42−64] % TBSA and were characterized by an ABSI of 10 [8−12] points. When receiving EHT management patients experienced warming at 0.07 °C per minute (4.2 °C/h) compared to a temperature loss of − 0.03 °C per minute (1.8 °C/h) when only receiving standard temperature management (p < 0.0001). No adverse or serious adverse events were reported. The use of an oesophageal heat transfer device was effective and safe in providing perioperative warming to severely burned patients when compared to a standard temperature management protocol. By employing an EHT as primary temperature management device perioperative hypothermia in severely burned patients can possibly be averted, potentially leading to reduced hypothermia-associated complications. • EHT was associated with intraoperative warming as opposed to standard temperature management. • This study shows that the use of an EHT was effective and safe. • EHT can potentially leading to reduced hypothermia-associated complications. [ABSTRACT FROM AUTHOR]

Simple Summary: Lung cancer is a serious burden worldwide. The growth of lung tumors depends on vessel density and intratumoral copper concentration. Copper chelating agents can reduce copper content in tumor tissue, resulting in lower vessel density and lower tumor weight. PSP-2, a very potent copper chelator, was tested on lung tumor grafts that were on-planted on the chorioallantoic membrane of the chicken embryo. We found a lower vessel density and a lower tumor weight under PSP-2 application compared to the controls. Thus, PSP-2 could be a potential therapeutic agent to treat lung cancer in the future. Human lung cancer ranks among the most frequently treated cancers worldwide. As copper appears critical to angiogenesis and tumor growth, selective removal of copper represents a promising strategy to restrict tumor growth. To this end, we explored the activity of the novel high-affinity membrane-permeant Cu(I) chelator PSP-2 featuring a low-zeptomolar dissociation constant. Using H460 human lung cancer cells, we generated small tumors on the chorioallantoic membrane of the chicken embryo (CAM assay) and studied the effects of topical PSP-2 application on their weight and vessel density after one week. We observed a significant angiosuppression along with a marked decrease in tumor weight under PSP-2 application compared to controls. Moreover, PSP-2 exposure resulted in lower ki67+ cell numbers at a low dose but increased cell count under a high dose. Moreover, HIF-1α+ cells were significantly reduced with low-dose PSP-2 exposure compared to high-dose and control. The total copper content was considerably lower in PSP-2 treated tumors, although statistically not significant. Altogether, PSP-2 shows promising potential as an anti-cancer drug. Nevertheless, further animal experiments and application to different tumor types are mandatory to support these initial findings, paving the way toward clinical trials. [ABSTRACT FROM AUTHOR]

Background: Renal tubular acidosis (RTA) is an extremely rare cause of metabolic acidosis (10 in 100,000). RTA has been linked neither to pregnancy nor to severe coronavirus disease 2019 (COVID-19). The purpose of this study was to analyze the prevalence and clinical course of normal anion gap metabolic acidosis in critically ill pregnant COVID-19 patients and to compare them to an age-matched nonpregnant female patient cohort. Methods: Secondary analysis was conducted on a prospective observational cohort of critically ill patients suffering from COVID-19 consecutively admitted to a tertiary intensive care unit (ICU) between February 2020 and April 2021. Results: A total of 321 COVID-19 patients required admission to the ICU; 95 (30%) were female, and 18 (19%) were of childbearing age. Seven of eight (88%) pregnant women (all in the last trimester) required advanced respiratory support due to COVID-19. The estimated glomerular filtration rate was 135 (123–158) mL/min/m2 body surface area, and six pregnant women (86%) were diagnosed with a normal, respiratory compensated, anion gap metabolic acidosis (pHmin 7.3 (7.18–7.31), HCO3−min 14.8 (12.8–18.6) mmol/L, and paCO2 3.4 (3.3–4.5) kPa). Three (43%) acidotic pregnant women fulfilled diagnostic criteria for RTA. All women recovered spontaneously within less 7 days. Conclusions: Metabolic acidosis seems to be very common (85%) in pregnant critically ill COVID-19 patients, and the prevalence of RTA might be higher than normal. It remains to be demonstrated if this observation is an indirect epiphenomenon or due to a direct viral effect on the tubular epithelium. [ABSTRACT FROM AUTHOR]

Autoantibodies neutralizing the antiviral action of type I interferons (IFNs) have been associated with predisposition to severe Coronavirus Disease 2019 (COVID-19). Here, we screened for such autoantibodies in 103 critically ill COVID-19 patients in a tertiary intensive care unit (ICU) in Switzerland. Eleven patients (10.7%), but no healthy donors, had neutralizing anti-IFNα or anti-IFNα/anti-IFNω IgG in plasma/serum, but anti-IFN IgM or IgA was rare. One patient had nonneutralizing anti-IFNα IgG. Strikingly, all patients with plasma anti-IFNα IgG also had anti-IFNα IgG in tracheobronchial secretions, identifying these autoantibodies at anatomical sites relevant for Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) infection. Longitudinal analyses revealed patient heterogeneity in terms of increasing, decreasing, or stable anti-IFN IgG levels throughout the length of hospitalization. Notably, presence of anti-IFN autoantibodies in this critically ill COVID-19 cohort appeared to predict herpesvirus disease (caused by herpes simplex viruses types 1 and 2 (HSV-1/-2) and/or cytomegalovirus (CMV)), which has been linked to worse clinical outcomes. Indeed, all 7 tested COVID-19 patients with anti-IFN IgG in our cohort (100%) suffered from one or more herpesviruses, and analysis revealed that these patients were more likely to experience CMV than COVID-19 patients without anti-IFN autoantibodies, even when adjusting for age, gender, and systemic steroid treatment (odds ratio (OR) 7.28, 95% confidence interval (CI) 1.14 to 46.31, p = 0.036). As the IFN system deficiency caused by neutralizing anti-IFN autoantibodies likely directly and indirectly exacerbates the likelihood of latent herpesvirus reactivations in critically ill patients, early diagnosis of anti-IFN IgG could be rapidly used to inform risk-group stratification and treatment options. Trial Registration: ClinicalTrials.gov Identifier: NCT04410263. Autoantibodies that neutralize the antiviral action of type I interferons are associated with predisposition to severe COVID-19. This study shows that this deficiency in the interferon system is associated with a heightened risk of herpesvirus disease in critically ill patients infected with SARS-CoV-2. [ABSTRACT FROM AUTHOR]

Objectives: Extracorporeal membrane oxygenation (ECMO) is a potentially lifesaving procedure in acute respiratory distress syndrome (ARDS) due to COVID-19. Previous studies have shown a high prevalence of clinically silent cerebral microbleeds in patients with COVID-19. Based on this fact, together with the hemotrauma and the requirement of therapeutic anticoagulation on ECMO support, we hypothesized an increased risk of intracranial hemorrhages (ICHs). We analyzed ICH occurrence rate, circumstances and clinical outcome in patients that received ECMO support due to COVID-19-induced ARDS in comparison to viral non-COVID-19-induced ARDS intracerebral hemorrhage.Design: Multicenter, retrospective analysis between January 2010 and May 2021.Setting: Three tertiary care ECMO centers in Germany and Switzerland.Patients: Two-hundred ten ARDS patients on ECMO support (COVID-19, n = 142 vs viral non-COVID, n = 68).Interventions: None.Measurements and Main Results: Evaluation of ICH occurrence rate, parameters of coagulation and anticoagulation strategies, inflammation, and ICU survival. COVID-19 and non-COVID-19 ARDS patients showed comparable disease severity regarding Sequential Organ Failure Assessment score, while the oxygenation index before ECMO cannulation was higher in the COVID group (82 vs 65 mm Hg). Overall, ICH of any severity occurred in 29 of 142 COVID-19 patients (20%) versus four of 68 patients in the control ECMO group (6%). Fifteen of those 29 ICH events in the COVID-19 group were classified as major (52%) including nine fatal cases (9/29, 31%). In the control group, there was only one major ICH event (1/4, 25%). The adjusted subhazard ratio for the occurrence of an ICH in the COVID-19 group was 5.82 (97.5% CI, 1.9-17.8; p = 0.002). The overall ICU mortality in the presence of ICH of any severity was 88%.Conclusions: This retrospective multicenter analysis showed a six-fold increased adjusted risk for ICH and a 3.5-fold increased incidence of ICH in COVID-19 patients on ECMO. Prospective studies are needed to confirm this observation and to determine whether the bleeding risk can be reduced by adjusting anticoagulation strategies. [ABSTRACT FROM AUTHOR]

TEN/DRESS overlap syndrome can be difficult to diagnose, especially if it is masked by comorbidities in critically ill patients in intensive care units. The existing therapy for the two conditions is also a major challenge for the treating team. A possible alternative, especially for refractory cases, is benralizumab as an IL-5-receptor alpha-chain-specific humanized monoclonal antibody (IgG1k). We are able to show a successful treatment in this case report. [ABSTRACT FROM AUTHOR]

First, despite older age and elevated risk profile, vaccinated ICU patients had less severe lung and systemic organ failure, need for mechanical ventilation and shorter ICU length-of-stay, yet still similar ICU mortality. ICU mortality estimates were modeled using a Cox proportional hazards model, with an underlying time scale of ICU admission until date of death or date of discharge which was defined as censoring event, with ICU mortality entered as event and ICU survival entered as censored event. [Extracted from the article]

Background: Necrotizing soft-tissue infections are infections with high mortality. The use of immunoglobulins within a combination therapy including broad-spectrum antibiotics has been debated. We assessed potential benefits of immunoglobulins and hypothesized that they were associated with a treatment benefit in a high-resource setting.Methods: Patients with necrotizing soft-tissue infection hospitalized in the tertiary intensive care unit of the University Hospital of Zurich, Switzerland, between 2008 and 2020 were included retrospectively. The association between immunoglobulin administration and in-hospital survival, intensive care unit length of stay, the incidences of acute renal failure, acute respiratory distress syndrome and septic shock were analyzed.Results: After adjustment for confounders, no difference for in-hospital survival (hazard ratio 2.20, 95% confidence interval [CI] 0.24-20.20, p = 0.5), intensive care unit length of stay (subhazard ratio [SHR] 0.90, CI 0.41-1.98, p = 0.8) and the development of acute respiratory distress syndrome (SHR 1.2, CI 0.36-4.03, p = 0.77) was observed in patients with or without immunoglobulin treatment. The Simplified Acute Physiology Score II, the risk of developing acute renal failure (SHR 2.86, CI 1.33-6.15, p = 0.01) and septic shock (SHR 1.86, CI 1.02-3.40, p = 0.04) was higher in patients treated with immunoglobulins, possibly reflecting a higher disease severity beyond measured confounders.Conclusions: No clear evidence for a benefit of immunoglobulins in our cohort with consistent antibiotic use was found. Patients receiving immunoglobulins appeared more severely ill. Complementary to high treatment standards and appropriate antibiotics including beta lactams and protein synthesis inhibitors, immunoglobulins should be administered on a case-to-case basis, at least while more evidence from larger randomized controlled trials is missing. [ABSTRACT FROM AUTHOR]

COVID-19 displays diverse disease severities and symptoms including acute systemic inflammation and hypercytokinemia, with subsequent dysregulation of immune cells. Bacterial superinfections in COVID-19 can further complicate the disease course and are associated with increased mortality. However, there is limited understanding of how SARS-CoV-2 pathogenesis and hypercytokinemia impede the innate immune function against bacterial superinfections. We assessed the influence of COVID-19 plasma hypercytokinemia on the functional responses of myeloid immune cells upon bacterial challenges from acute-phase COVID-19 patients and their corresponding recovery (rec)-phase. We show that a severe hypercytokinemia status in COVID-19 patients correlates with the development of bacterial superinfections. Neutrophils and monocytes derived from COVID-19 patients in their acute-phase showed an impaired intracellular microbicidal capacity upon bacterial challenges. The impaired microbicidal capacity was reflected by abrogated MPO and reduced NETs production in neutrophils along with reduced ROS production in both neutrophils and monocytes. Moreover, we observed a distinct pattern of cell surface receptor expression on both neutrophils and monocytes, in line with suppressed autocrine and paracrine cytokine signaling. This phenotype was characterized by a high expression of CD66b, CXCR4 and low expression of CXCR1, CXCR2 and CD15 in neutrophils and low expression of HLA-DR, CD86 and high expression of CD163 and CD11b in monocytes. Furthermore, the impaired antibacterial effector function was mediated by synergistic effect of the cytokines TNF-α, IFN-γ and IL-4. COVID-19 patients receiving dexamethasone showed a significant reduction of overall inflammatory markers in the plasma as well as exhibited an enhanced immune response towards bacterial challenge ex vivo. Finally, broad anti-inflammatory treatment was associated with a reduction in CRP, IL-6 levels as well as length of ICU and hospital stay in critically ill COVID-19 patients. Our data provides insights into the transient functional dysregulation of myeloid immune cells against subsequent bacterial infections in COVID-19 patients and describe a beneficial role for the use of dexamethasone in these patients. Author summary: COVID-19 caused by SARS-CoV-2 induces immune-paralysis characterized by misdirected host responses and altered levels of inflammatory mediators. Additionally, bacterial superinfections can further exacerbate the disease. Here, we report an in-depth functional characterization of the effector response and phenotypic properties of neutrophils and monocytes derived from critically ill COVID-19 patients towards bacterial superinfection. We show that elevated levels of specific cytokine clusters, positively correlate with the development of bacterial superinfections in these patients. Neutrophils and monocytes of critically ill COVID-19 patients showed impaired bactericidal capacity, which was mediated by elevated inflammatory mediators in the plasma. The observed impaired bactericidal capacity in critically ill COVID-19 patients was due to reduced classical effector functions of neutrophils and monocytes. Interestingly, lower levels of overall inflammatory mediators as well as reduction in length of ICU and hospital stay in critically ill COVID-19 patients treated with dexamethasone was observed. These data suggest that the exhaustion and paralysis of the cellular innate immunity against bacterial challenge in critically ill COVID-19 patients is driven by a misdirected host-response, characterized by a hyperinflammatory environment including dysregulated cytokine levels. These results further emphasize the utility and importance of dampening these inflammatory mediators via broad anti-inflammatory therapy in COVID-19 patients, which improves the antibacterial effector functions of neutrophils and monocytes. [ABSTRACT FROM AUTHOR]

Objectives: Critically ill coronavirus disease 2019 (COVID‐19) patients are characterised by a severely dysregulated cytokine profile and elevated neutrophil counts, impacting disease severity. However, it remains unclear how neutrophils contribute to pathophysiology during COVID‐19. Here, we assessed the impact of the dysregulated cytokine profile on the regulated cell death (RCD) programme of neutrophils. Methods: Regulated cell death phenotype of neutrophils isolated from critically ill COVID‐19 patients or healthy donors and stimulated with COVID‐19 or healthy plasma ex vivo was assessed by flow cytometry, time‐lapse microscopy and cytokine multiplex analysis. Immunohistochemistry of COVID‐19 patients and control biopsies were performed to assess the in situ neutrophil RCD phenotype. Plasma cytokine levels of COVID‐19 patients and healthy donors were measured by multiplex analysis. Clinical parameters were correlated to cytokine levels of COVID‐19 patients. Results: COVID‐19 plasma induced a necroptosis‐sensitive neutrophil phenotype, characterised by cell lysis, elevated release of damage‐associated molecular patterns (DAMPs), increased receptor‐interacting serine/threonine‐protein kinase (RIPK) 1 levels and mixed lineage kinase domain‐like pseudokinase (MLKL) involvement. The occurrence of neutrophil necroptosis MLKL axis was further confirmed in COVID‐19 thrombus and lung biopsies. Necroptosis was induced by the tumor necrosis factor receptor 1 (TNFRI)/TNF‐α axis. Moreover, reduction of soluble Fas ligand (sFasL) levels in COVID‐19 patients and hence decreased signalling to Fas directly increased RIPK1 levels, exacerbated TNF‐driven necroptosis and correlated with disease severity, which was abolished in patients treated with glucocorticoids. Conclusion: Our results suggest a novel role for sFasL signalling in the TNF‐α‐induced RCD programme in neutrophils during COVID‐19 and a potential therapeutic target to curb inflammation and thus influence disease severity and outcome. [ABSTRACT FROM AUTHOR]

Group A Streptococcus (GAS) has developed a broad arsenal of virulence factors that serve to circumvent host defense mechanisms. The virulence factor DNase Sda1 of the hyperinvasive M1T1 GAS clone degrades DNA-based neutrophil extracellular traps allowing GAS to escape extracellular killing. TLR9 is activated by unmethylated CpG-rich bacterial DNA and enhances innate immune resistance. We hypothesized that Sda1 degradation of bacterial DNA could alter TLR9-mediated recognition of GAS by host innate immune cells. We tested this hypothesis using a dual approach: loss and gain of function of DNase in isogenic GAS strains and presence and absence of TLR9 in the host. Either DNA degradation by Sda1 or host deficiency of TLR9 prevented GAS induced IFN-α and IFN-α secretion from murine macrophages and contributed to bacterial survival. Similarly, in a murine necrotizing fasciitis model, IFN-α and IFN-α levels were significantly decreased in wild type mice infected with GAS expressing Sda1, whereas no such Sda1-dependent effect was seen in a TLR9-deficient background. Thus GAS Sda1 suppressed both the TLR9-mediated innate immune response and macrophage bactericidal activity. Our results demonstrate a novel mechanism of bacterial innate immune evasion based on autodegradation of CpG-rich DNA by a bacterial DNase. [ABSTRACT FROM AUTHOR]

Background: SecDF is an accessory factor of the conserved Sec protein translocation machinery and belongs to the resistance-nodulation-cell division (RND) family of multidrug exporters. SecDF has been shown in Escherichia coli and Bacillus subtilis to be involved in the export of proteins. RND proteins can mediate resistance against various substances and might be of relevance in antimicrobial therapy. The role of RND proteins in Staphylococcus aureus has not yet been determined. Results: Markerless deletion mutants were constructed to analyze the impact of the so far uncharacterized RND proteins in S. aureus. While the lack of Sa2056 and Sa2339 caused no phenotype regarding growth and resistance, the secDF mutant resulted in a pleiotropic phenotype. The secDF mutant was cold sensitive, but grew normally in rich medium at 37°C. Resistance to beta-lactams, glycopeptides and the RND substrates acriflavine, ethidium bromide and sodium dodecyl sulfate was reduced. The secDF mutant showed an aberrant cell separation and increased spontaneous and Triton X-100 induced autolysis, although the amounts of penicillin-binding proteins in the membrane were unchanged. The impact of secDF deletion on transcription and expression of specific virulence determinants varied: While coagulase transcription and activity were reduced, the opposite was observed for the autolysin Atl. A reduction of the transcription of the cell wall anchored protein A (spa) was also found. The accumulation of SpA in the membrane and lowered amounts in the cell wall pointed to an impaired translocation. Conclusions: The combination of different effects of secDF deletion on transcription, regulation and translocation lead to impaired cell division, reduced resistance and altered expression of virulence determinants suggesting SecDF to be of major relevance in S. aureus. Thus SecDF could be a potential target for the control and eradication of S. aureus in the future. [ABSTRACT FROM AUTHOR]

Iron is essential for many biological processes, including oxygen delivery, and its supply is tightly regulated. Hepcidin, a small peptide synthesized in the liver, is a key regulator of iron absorption and homeostasis in mammals. Hepcidin production is increased by iron overload and decreased by anemia and hypoxia; but the molecular mechanisms that govern the hepcidin response to these stimuli are not known. Here we establish that the von Hippel—Lindau/hypoxia-inducible transcription factor (VHL/HIF) pathway is an essential link between iron homeostasis and hepcidin regulation in vivo. Through coordinate downregulation of hepcidin and upregulation of erythropoietin and ferroportin, the VHL-HIF pathway mobilizes iron to support erythrocyte production. [ABSTRACT FROM AUTHOR]

Iron is essential for many biological processes, including oxygen delivery, and its supply is tightly regulated. Hepcidin, a small peptide synthesized in the liver, is a key regulator of iron absorption and homeostasis in mammals. Hepcidin production is increased by iron overload and decreased by anemia and hypoxia; but the molecular mechanisms that govern the hepcidin response to these stimuli are not known. Here we establish that the von Hippel—Lindau/hypoxia-inducible transcription factor (VHL/HIF) pathway is an essential link between iron homeostasis and hepcidin regulation in vivo. Through coordinate downregulation of hepcidin and upregulation of erythropoietin and ferroportin, the VHL-HIF pathway mobilizes iron to support erythrocyte production. [ABSTRACT FROM AUTHOR]

Background: Lung-protective ventilation is key in bridging patients suffering from COVID-19 acute respiratory distress syndrome (ARDS) to recovery. However, resource and personnel limitations during pandemics complicate the implementation of lung-protective protocols. Automated ventilation modes may prove decisive in these settings enabling higher degrees of lungprotective ventilation than conventional modes. Method: Prospective study at a Swiss university hospital. Critically ill, mechanically ventilated COVID-19 ARDS patients were allocated, by study-blinded coordinating staff, to either closed-loop or conventional mechanical ventilation, based on mechanical ventilator availability. Primary outcome was the overall achieved percentage of lung-protective ventilation in closed-loop versus conventional mechanical ventilation, assessed minute-by-minute, during the initial 7 days and overall mechanical ventilation time. Lung-protective ventilation was defined as the combined target of tidal volume <8 ml per kg of ideal body weight, dynamic driving pressure <15 cmH2O, peak pressure <30 cmH2O, peripheral oxygen saturation -88% and dynamic mechanical power <17 J/min. Results: Forty COVID-19 ARDS patients, accounting for 1,048,630 minutes (728 days) of cumulative mechanical ventilation, allocated to either closed-loop (n = 23) or conventional ventilation (n = 17), presenting with a median paO2/FiO2 ratio of 92 [72-147] mmHg and a static compliance of 18 [11-25] ml/cmH2O, were mechanically ventilated for 11 [4-25] days and had a 28-day mortality rate of 20%. During the initial 7 days of mechanical ventilation, patients in the closed-loop group were ventilated lung-protectively for 65% of the time versus 38% in the conventional group (Odds Ratio, 1.79; 95% CI, 1.76-1.82; P < 0.001) and for 45% versus 33% of overall mechanical ventilation time (Odds Ratio, 1.22; 95% CI, 1.21-1.23; P < 0.001). Conclusion: Among critically ill, mechanically ventilated COVID-19 ARDS patients during an early highpoint of the pandemic, mechanical ventilation using a closed-loop mode was associated with a higher degree of lung-protective ventilation than was conventional mechanical ventilation. [ABSTRACT FROM AUTHOR]

Staphylococcus aureus causes invasive infections and easily acquires antibiotic resistance. Even antibiotic-susceptible S. aureus can survive antibiotic therapy and persist, requiring prolonged treatment and surgical interventions. These so-called persisters display an arrested-growth phenotype, tolerate high antibiotic concentrations, and are associated with chronic and recurrent infections. To characterize these persisters, we assessed S. aureus recovered directly from a patient suffering from a persistent infection. We show that host-mediated stress, including acidic pH, abscess environment, and antibiotic exposure promoted persister formation in vitro and in vivo. Multiomics analysis identified molecular changes in S. aureus in response to acid stress leading to an overall virulent population. However, further analysis of a persister-enriched population revealed major molecular reprogramming in persisters, including down-regulation of virulence and cell division and up-regulation of ribosomal proteins, nucleotide-, and amino acid-metabolic pathways, suggesting their requirement to fuel and maintain the persister phenotype and highlighting that persisters are not completely metabolically inactive. Additionally, decreased aconitase activity and ATP levels and accumulation of insoluble proteins involved in transcription, translation, and energy production correlated with persistence in S. aureus, underpinning the molecular mechanisms that drive the persister phenotype. Upon regrowth, these persisters regained their virulence potential and metabolically active phenotype, including reduction of insoluble proteins, exhibiting a reversible state, crucial for recurrent infections. We further show that a targeted antipersister combination therapy using retinoid derivatives and antibiotics significantly reduced lag-phase heterogeneity and persisters in a murine infection model. Our results provide molecular insights into persisters and help explain why persistent S. aureus infections are so difficult to treat. [ABSTRACT FROM AUTHOR]

Background: In intensive care units (ICUs) treating patients with Coronavirus disease 2019 (COVID-19) invasive ventilation poses a high risk for aerosol and droplet formation. Surface contamination of severe acute respiratory syndrome Coronavirus 2 (SARS-CoV-2) or bacteria can result in nosocomial transmission. Methods: Two tertiary care COVID-19 intensive care units treating 53 patients for 870 patient days were sampled after terminal cleaning and preparation for regular use to treat non-COVID-19 patients. Results: A total of 176 swabs were sampled of defined locations covering both ICUs. No SARS-CoV-2 ribonucleic acid (RNA) was detected. Gram-negative bacterial contamination was mainly linked to sinks and siphons. Skin flora was isolated from most swabbed areas and Enterococcus faecium was detected on two keyboards. Conclusions: After basic cleaning with standard disinfection measures no remaining SARS-CoV-2 RNA was detected. Bacterial contamination was low and mainly localised in sinks and siphons. [ABSTRACT FROM AUTHOR]

Purpose: Estimation of cardiac output (CO) and evaluation of change in CO as a result of therapeutic interventions are essential in critical care medicine. Whether noninvasive tools estimating CO, such as continuous cardiac output (esCCOTM) methods, are sufficiently accurate and precise to guide therapy needs further evaluation. We compared esCCOTM with an established method, namely, transpulmonary thermodilution (TPTD). Patients and Methods. In a single center mixed ICU, esCCOTM was compared with the TPTD method in 38 patients. The primary endpoint was accuracy and precision. The cardiac output was assessed by two investigators at baseline and after eight hours.Results: In 38 critically ill patients, the two methods correlated significantly (r = 0.742). The Bland-Altman analysis showed a bias of 1.6 l/min with limits of agreement of -1.76 l/min and +4.98 l/min. The percentage error for COesCCO was 47%. The correlation of trends in cardiac output after eight hours was significant (r = 0.442), with a concordance of 74%. The performance of COesCCO could not be linked to the patient's condition.Conclusion: The accuracy and precision of the esCCOTM method were not clinically acceptable for our critical patients. EsCCOTM also failed to reliably detect changes in cardiac output. [ABSTRACT FROM AUTHOR]

• The role of circulating Angiopoietin-2 has never been assessed in burns. • The Angiopoietin-2/-1 ratio increases in the first 48 h after burn insult. • An increased Angiopoietin-2/-1 ratio is associated with higher mortality. Angiopoietin-2 (Angpt-2) is involved in the pathogenesis of the capillary leak syndrome in sepsis and has been shown to be associated with worse outcomes in diverse critical illnesses. It is however unclear whether Angpt-2 plays a similar role in severely burned patients during the early phase characterized by massive capillary leakage. Our aim was to analyze the Angiopoietin-2/Angiopoietin-1 ratio (Angpt-2/Angpt-1 ratio) over the first two days in critically ill burn patients and examine its association with survival and further clinical parameters. Adult burn patients with a total burn surface area (TBSA) ≥ 20% treated in the burn intensive care unit (ICU) of the University Hospital of Zurich, Switzerland, were included. Serum samples were collected prospectively and serum Angpt-1 and Angpt-2 were measured by enzyme-linked immunosorbent assay (ELISA) over the first two days after burn insult and stratified according to survival status, TBSA and the abbreviated burn severity index (ABSI). Due to hemodilution in the initial resuscitation phase, the Angpt-2/Angpt-1 ratio was normalized to albumin. Fifty-six patients were included with a median age of 51.5 years. Overall mortality was 14.3% (8/56 patients). The total amount of infused crystalloids was 12́902 ml (IQR 9́362–16́770 ml) at 24 h and 18́461 ml (IQR 13́024–23́766 ml) at 48 h. The amount of substituted albumin was 20 g (IQR 10–50 g) at 24 h and 50 g (IQR 20–60 g) at 48 h. The albumin-corrected Angpt-2/Angpt-1 ratios increased over the first 48 h after the burn insult (d0: 0.5 pg*l/ml*g [IQR 0.24 – 0.80 pg*l/ml*g]; d1: 0.83 pg*l/ml*g [IQR 0.29 – 1.98 pg*l/ml*g]; d2: 1.76 pg*l/ml*g [IQR 0.70 – 3.23 pg*l/ml*g]; p < 0.001) and were significantly higher in eventual ICU non-survivors (p = 0.005), in patients with a higher TBSA (p = 0.001) and in patients with a higher ABSI (p = 0.001). In analogy to the pathological host response in sepsis, the Angpt-2/Angpt-1 ratio steadily increases in the first two days in critically ill burn patients, suggesting a putative involvement in the pathogenesis of capillary leakage in burns. A higher Angpt-2/Angpt-1 ratio is associated with mortality, total burn surface area and burn scores. [ABSTRACT FROM AUTHOR]

Protease-activated receptors (PARs) evolved to react to extracellular proteolytic activity. In mammals, three of the four PARs (PAR1, PAR3, and PAR4) that are expressed respond to the prototypical procoagulant enzyme thrombin, whereas PAR2 was assumed to resist activation by thrombin. To date, involvement of cell surface thrombin-recruiting co-receptors such as thrombomodulin (TM), which potentially facilitates PAR2 cleavage, has not been addressed. Thus, we examined whether TM-bound thrombin cleaved PAR2 and tested biological responses such as nuclear factor kappa B (NF-κB) DNA binding activity and cytokine release. We examined 293T cells overexpressing PAR2 and TM for thrombin recruitment by TM promoting PAR2 cleavage. To test for the TM–thrombin interactions required for PAR2 cleavage and to map cleavage sites on PAR2, mutant constructs of TM or PAR2 were engineered. Biological effects because of PAR2 activation were investigated using an NF-κB reporter system and cytokine release. We identified that, at low to moderate concentrations, thrombin cleaved PAR2 in a TM co-receptor-dependent manner with cleavage efficiency comparable to that of trypsin. In TM's presence, thrombin efficiently cleaved both, PAR1 and PAR2, albeit kinetics differed. Whereas the majority of surface expressed PAR1 was immediately cleaved off, prolonged exposure to thrombin resulted in few additional cleavage. In contrast, PAR2 cleavage was sustained upon prolonged exposure to thrombin. However, TM EGF-like domain 5 was required and TM chondroitin sulfate (CS) proteoglycan sites serine 490 and serine 492 assisted in PAR2 cleavage, while thrombin preferentially cleaved at arginine 36 on PAR2's N-terminus. Note that thrombin-induced activation of NF-κB via PAR2 resulted in release of interleukin-8. Thus, we provide a novel concept of how thrombin efficiently cleaves PAR2 in a TM-dependent manner, resulting in pro-inflammatory interleukin-8 release. This unexpected pro-inflammatory role of TM, promoting cleavage and activation of PAR2 by thrombin, may lead to novel therapeutic options for treating inflammatory and malignant diseases. Unlabelled Image • Co-receptor-dependent cleavage of PAR2 by thrombin has not been considered thus far. • Low to moderate concentrations of thrombomodulin-bound thrombin efficiently cleaved PAR2. • Thrombin triggered IL-8 in a PAR2- and thrombomodulin-dependent manner in overexpression and native cell systems. • PAR2 activated by thrombin in presence of thrombomodulin induced NF-kB DNA binding activity. [ABSTRACT FROM AUTHOR]

Abstract: Grade 3 primary graft dysfunction (PGD3) represents the most important risk factor for patient mortality during the first year after lung transplantation (LTX). We investigated whether pretransplant pulmonary hypertension (PH) is a risk factor for the development of PGD3. This retrospective, single‐center cohort study included 96 candidates undergoing right heart catheterization (RHC) prior to being listed for LTX between March 2000 and October 2015. Based on their mean pulmonary artery pressure (mPAP) levels, the patients were classified into 3 groups: (1) <25 mm Hg, (2) 25‐34 mm Hg and (3) ≥35 mm Hg. Forty‐seven patients were classified in group 1, 31 in group 2, and 18 in group 3. Fifteen recipients (16%, 95%‐CI 8‐23) developed PGD3. In the univariate analysis, the diagnosis of interstitial lung disease (ILD) compared to COPD (OR: 7.06, P = .005), blood transfusion >1000 mL during surgery (OR: 5.25, P = .005), the need for intra‐operative cardio‐pulmonary bypass (CPB) or extra‐corporeal membrane oxygenation (ECMO) (OR: 4, P = .027), mPAP (OR 1.06, P = .007) and serum high density lipoprotein‐cholesterol (HDL‐C) (OR 0.09, P = .005) were associated with PGD3. In the multivariable logistic regression analysis, only HDL‐C (OR 0.10, P = .016) was associated with PGD3 based on our single‐center cohort data analysis. [ABSTRACT FROM AUTHOR]

Background: Necrotizing fasciitis (NF) retains a very high mortality rate despite prompt and adequate antibiotic treatment and surgical debridement. Necrotizing fasciitis has recently been associated with Streptococcus dysgalactiae subspecies equisimilis (SDSE).Methods: We investigated the causes of a very severe clinical manifestation of SDSE-NF by assessing both host and pathogen factors.Results: We found a lack of streptokinase-function blocking antibodies in the patient resulting in increased streptokinase-mediated fibrinolysis and bacterial spread. At the same time, the clinical SDSE isolate produced very high levels of streptokinase. Exogenous immunoglobulin Gs (ex-IgGs) efficiently blocked streptokinase-mediated fibrinolysis in vitro, indicating a protective role against the action of streptokinase. In vivo, SDSE infection severity was also attenuated by ex-IgGs in a NF mouse model.Conclusions: These findings illustrate for the first time that the lack of specific antibodies against streptococcal virulence factors, such as streptokinase, may contribute to NF disease severity. This can be counteracted by ex-IgGs. [ABSTRACT FROM AUTHOR]

Group A Streptococcus (GAS) has acquired an arsenal of virulence factors, promoting life-threatening invasive infections such as necrotizing fasciitis. Current therapeutic regimens for necrotizing fasciitis include surgical debridement and treatment with cell wall-active antibiotics. Addition of clindamycin (CLI) is recommended, although clinical evidence is lacking. Reflecting the current clinical dilemma, an observational study showed that only 63% of the patients with severe invasive GAS infection received CLI. This work thus aimed to address whether CLI improves necrotizing fasciitis outcome by modulating virulence factors of CLI-susceptible and CLI-resistant GAS in vitro and in vivo. Treatment with CLI reduced extracellular DNase Sda1 and streptolysin O (SLO) activity in vivo, whereas subinhibitory CLI concentrations induced expression and activity of SLO, DNase, and Streptococcus pyogenes cell envelope protease in vitro. Our in vivo results suggest that CLI should be administered as soon as possible to patients with necrotizing fasciitis, while our in vitro studies emphasize that a high dosage of CLI is essential. [ABSTRACT FROM AUTHOR]

Background: Neutrophils and monocytes are crucial for controlling bacterial infections. More-frequent bacterial infections are accordingly encountered in neutropenic patients undergoing chemotherapy. This is not the case for pegylated interferon α (IFN-α)-induced neutropenia. We hypothesized that IFN-α induces a compensatory innate antibacterial state that prevents bacterial infections despite the neutropenia.Methods: To investigate whether patients with hepatitis C virus infection treated with IFN-α killed group A Streptococcus (GAS) better than before initiating therapy, whole blood was used to perform ex vivo GAS killing assays before, during, and after IFN-α therapy.Results: We found that IFN-α therapy enhanced GAS killing in whole blood ex vivo despite the decreased neutrophil and monocyte numbers during IFN-α therapy. IFN-α also boosted neutrophil- and monocyte-mediated GAS killing in vitro. Underlying mechanisms included increased production of the antibacterial properdin, a regulator of the complement activation, as well as reactive oxygen species.Conclusions: These findings help to explain the rather discrepant facts of neutropenia but preserved antibacterial immune defenses in patients treated with IFN-α. [ABSTRACT FROM AUTHOR]

Background: Staphylococcus aureus-infected patients treated with antibiotics that are effective in vitro often experience relapse of infection because the bacteria hide in privileged locations. These locations include abscesses and host cells, which contain low-pH compartments and are sites from which nonstable S. aureus small-colony variants (SCVs) are frequently recovered.Methods: We assessed the effect of low pH on S. aureus colony phenotype and bacterial growth, using in vitro and in vivo models of long-term infection.Results: We showed that low pH induced nonstable SCVs and nonreplicating persisters that are capable of regrowth. Within host cells, S. aureus was located in phagolysosomes, a low-pH compartment. Therapeutic neutralization of phagolysosomal pH with ammonium chloride, bafilomycin A1, or the antimalaria drug chloroquine reduced SCVs in infected host cells. In a systemic mouse infection model, treatment with chloroquine also reduced SCVs.Conclusions: Our results show that the acidic environment favors formation of nonstable SCVs, which reflect the SCVs found in clinics. They also provide evidence that treatment with alkalinizing agents, together with antibiotics, may provide a novel translational strategy for eradicating persisting intracellular reservoirs of staphylococci. This approach may also be extended to other intracellular bacteria. [ABSTRACT FROM AUTHOR]

Difficult-to-treat infections caused by antibiotic-susceptible strains have been linked to the occurrence of persisters, a subpopulation of dormant bacteria that tolerate antibiotic exposure despite lacking genetic resistance. These persisters can be identified phenotypically by plating on nutrient agar because of their altered growth dynamics, resulting in colony-size heterogeneity. The occurrence of within-patient bacterial phenotypic heterogeneity in various infections and clinical determinants of persister formation remains unknown. We plated bacteria derived from 132 patient samples of difficult-to-treat infections directly on nutrient-rich agar and monitored colony growth by time-lapse imaging. We retained 36 Staphylococcus aureus monocultures for further analysis. We investigated clinical factors associated with increased colony growth-delay with regression analyses. We corroborated the clinical findings using in vitro grown static biofilms exposed to distinct antibiotics. The extent of phenotypic heterogeneity of patient-derived S. aureus varied substantially between patients (from no delay to a maximum of 57.6 hours). Increased heterogeneity coincided with increased median colony growth-delay. Multivariable regression showed that rifampicin treatment was significantly associated with increased median growth-delay (13.3 hours; 95% CI 7.13–19.6 hours; p < 0.001). S. aureus grown in biofilms and exposed to high concentrations of rifampicin or a combination of rifampicin with clindamycin or levofloxacin exhibited prolonged growth-delay (p < 0.05 for 11 of 12 comparisons), correlating with a strain-dependent increase in antibiotic tolerance. Colony-size heterogeneity upon direct sampling of difficult-to-treat S. aureus infections was frequently observed. Hence, future studies are needed to assess the potential benefit of phenotypic heterogeneity quantification for staphylococcal infection prognosis and treatment guidelines. [Display omitted] [ABSTRACT FROM AUTHOR]

The Gram-positive human pathogen Staphylococcus aureus causes a variety of human diseases such as skin infections, pneumonia, and endocarditis. The micrococcal nuclease Nuc1 is one of the major S. aureus virulence factors and allows the bacterium to avoid neutrophil extracellular trap (NET)-mediated killing. We found that addition of the protein synthesis inhibitor clindamycin to S. aureus LAC cultures decreased nuc1 transcription and subsequently blunted nuclease activity in a molecular beacon-based fluorescence assay. We also observed reduced NET degradation through Nuc1 inhibition translating into increased NET-mediated clearance. Similarly, pooled human immunoglobulin specifically inhibited nuclease activity in a concentration-dependent manner. Inhibition of nuclease activity by clindamycin and immunoglobulin enhanced S. aureus clearance and should be considered in the treatment of S. aureus infections. [ABSTRACT FROM AUTHOR]

The Gram-positive human pathogen Staphylococcus aureus causes a variety of human diseases such as skin infections, pneumonia, and endocarditis. The micrococcal nuclease Nuc1 is one of the major S. aureus virulence factors and allows the bacterium to avoid neutrophil extracellular trap (NET)–mediated killing. We found that addition of the protein synthesis inhibitor clindamycin to S. aureus LAC cultures decreased nuc1 transcription and subsequently blunted nuclease activity in a molecular beacon–based fluorescence assay. We also observed reduced NET degradation through Nuc1 inhibition translating into increased NET-mediated clearance. Similarly, pooled human immunoglobulin specifically inhibited nuclease activity in a concentration-dependent manner. Inhibition of nuclease activity by clindamycin and immunoglobulin enhanced S. aureus clearance and should be considered in the treatment of S. aureus infections. [ABSTRACT FROM PUBLISHER]

Group A Streptococcus (GAS) is a human pathogen causing a wide range of mild to severe and life-threatening diseases. The GAS M1 protein is a major virulence factor promoting GAS invasiveness and resistance to host innate immune clearance. M1 displays an irregular coiled-coil structure, including the B-repeats that bind fibrinogen. Previously, we found that B-repeat stabilisation generates an idealised version of M1 (M1*) characterised by decreased fibrinogen binding in vitro. To extend these findings based on a soluble truncated version of M1, we now studied the importance of the B-repeat coiled-coil irregularities in full length M1 and M1* expressed in live GAS and tested whether the modulation of M1-fibrinogen interactions would open up novel therapeutic approaches. We found that altering either the M1 structure on the GAS cell surface or removing its target host protein fibrinogen blunted GAS virulence. GAS expressing M1* showed an impaired ability to adhere to and to invade human endothelial cells, was more readily killed by whole blood or neutrophils and most importantly was less virulent in a murine necrotising fasciitis model. M1-mediated virulence of wild-type GAS was strictly dependent on the presence and concentration of fibrinogen complementing our finding that M1-fibrinogen interactions are crucial for GAS virulence. Consistently blocking M1-fibrinogen interactions by fragment D reduced GAS virulence in vitro and in vivo. This supports our conclusion that M1-fibrinogen interactions are crucial for GAS virulence and that interference may open up novel complementary treatment options for GAS infections caused by the leading invasive GAS strain M1. [ABSTRACT FROM AUTHOR]

Background: There is little knowledge about the effect of dyslipidaemia on the outcome after lung transplantation. Thus, the aim of this retrospective single centre study was to analyse the impact of the plasma lipid profile on mortality in lung transplant recipients. From January 2000 to December 2008 the charts of 172 consecutive lung transplantation recipients were analysed. At baseline and after one year lipid profiles were routinely collected. During the follow-up major cardiovascular events (MCE; beginning of dialysis, cerebrovascular insult or myocardial infarction) were recorded. The follow-up period ended December 2010. Findings: Over all total cholesterol (4.3 ± 1.6 vs. 5.4 ± 1.3 mmol/l, p < 0.0001), triglycerides (1.2 ± 0.7 vs. 2.4 ± 1.3 mmol/l, p < 0.0001), HDL (1.5 ± 0.6 vs. 1.7 ± 0.6 mmol/l, p = 0.003) and TC/HDL ratio (3.0 ± 1.0 vs. 3.6 ± 1.2, p = 0.002) increased significantly after 1 year. During the observational period 6.9% (10 patients) suffered a major cardiac event. In univariate analysis MCE was associated with baseline TC: on average the event-group had a 33% higher baseline TC (5.6 vs. 4.2 mmol/l, OR 1.6, CI 1.1 - 2.2, p = 0.02). The total mortality in the observational period was 25% (36 patients overall). In univariate analysis mortality was associated with increased TC/HDL ratio. The non-survivors had on average a 22% higher baseline TC/HDL ratio (3.6 vs. 2.8, HR 2.8, CI 1.2 - 3.5, p = 0.001). There was no association between mortality and TC (p = 0.33), triglycerides (p = 0.34), HDL (p = 0.78) and creatinine (p = 0.73). In a multivariate model the hazard ratio was 1.5 (1.2 - 1.9, p = 0.001) per increase of 0.4 TC/HDL ratio. Conclusions: This study shows that the total cholesterol before transplantation is associated with the incidence of MCE and the cholesterol/HDL ratio with mortality in lung transplanted recipients [ABSTRACT FROM AUTHOR]

Oberkofler CE, Stocker R, Raptis DA, Stover JF, Schuepbach RA, Müllhaupt B, Dutkowski P, Clavien P-A, Béchir M. Same quality - higher price? The paradox of allocation: the first national single center analysis after the implementation of the new Swiss transplantation law: the ICU view. Clin Transplant 2011: 25: 921-928. © 2010 John Wiley & Sons A/S. Abstract: This study was undertaken as the first national single-center analysis to assess the impact of the new Swiss transplantation law on patient selection, intensive care unit (ICU) complications, outcome, and, in particular, costs in liver transplant recipients treated in our surgical ICU. The first 35 consecutive liver transplant recipients following the new act were compared with the last 35 liver transplant recipients preceding July 1, 2007. Following execution of the new law, recipients were in poorer condition, reflected by significant higher Model for End-Stage Liver Disease (MELD) scores (12 vs. 22; p = 0.006). Furthermore, the MELD group obtained more renal replacement therapies (40.0% vs. 14.3%; p = 0.015). Cumulative one-yr patient survival was comparable in both groups (91.4% vs. 80.1%, p = 0.22). Finally, the additional costs per single case increased 27 000 Euros after the adoption of the new law. Our data serve as an example that political decisions influence patient's selection, and, in turn, complications, finally leading to higher costs of medical treatment. Liver graft allocation according to the MELD system may save lives at the price of increased intensive care efforts. [ABSTRACT FROM AUTHOR]

Background. The Molecular Adsorbent Recirculating System (MARS) has been shown to clear albumin-bound toxins from patients with liver failure but might cause bleeding complications potentially obscuring survival benefits. We hypothesized that monitoring clotting parameters and bed-side thromboelastography allows to reduce bleeding complications. Methods. Retrospective analysis of 25 MARS sessions during which clotting parameters were monitored by a standardized protocol. Results. During MARS therapy median INR increased significantly from 1.7 to 1.9 platelet count and fibrinogen content decreased significantly from 57 fL(-1) to 42 fL(-1) and 2.1 g/L to 1.5 g/L. Nine relevant complications occurred: the MARS system clotted 6 times 3 times we observed hemorrhages. Absent thrombocytopenia and elevated plasma fibrinogen predicted clotting of the MARS system (ROC 0.94 and 0.82). Fibrinolysis, detected by thromboelastography, uniquely predicted bleeding events. Conclusion. Bed-side thromboelastography and close monitoring of coagulation parameters can predict and, therefore, help prevent bleeding complications during MARS therapy. [ABSTRACT FROM AUTHOR]

Background: Less is known about the influence of hematocrit detection methodology on transfusion triggers. Therefore, the aim of the present study was to compare two different hematocrit-assessing methods. In a total of 50 critically ill patients hematocrit was analyzed using (1) blood gas analyzer (ABLflex 800) and (2) the central laboratory method (ADVIA® 2120) and compared. Findings: Bland-Altman analysis for repeated measurements showed a good correlation with a bias of +1.39% and 2 SD of±3.12%. The 24%-hematocrit-group showed a correlation of r² = 0.87. With a kappa of 0.56, 22.7% of the cases would have been transfused differently. In the-28%-hematocrit group with a similar correlation (r² = 0.8) and a kappa of 0.58, 21% of the cases would have been transfused differently. Conclusions: Despite a good agreement between the two methods used to determine hematocrit in clinical routine, the calculated difference of 1.4% might substantially influence transfusion triggers depending on the employed method. [ABSTRACT FROM AUTHOR]

Cardiovascular complications are rapidly emerging as a key threat in coronavirus disease 2019 (COVID-19) in addition to respiratory disease. Intriguingly, SARS-CoV-2 can directly infect engineered human blood vessel organoids in vitro.[4] Here we demonstrate endothelial cell involvement across vascular beds of different organs in a series of patients with COVID-19 (further case details are provided in the appendix). She developed progressive respiratory failure due to COVID-19 and subsequently developed multi-organ failure and needed renal replacement therapy. [Extracted from the article]