(1) Background: SeptiCyte RAPID is a molecular test for discriminating sepsis from non-infectious systemic inflammation, and for estimating sepsis probabilities. The objective of this study was the clinical validation of SeptiCyte RAPID, based on testing retrospectively banked and prospectively collected patient samples. (2) Methods: The cartridge-based SeptiCyte RAPID test accepts a PAXgene blood RNA sample and provides sample-to-answer processing in ~1 h. The test output (SeptiScore, range 0–15) falls into four interpretation bands, with higher scores indicating higher probabilities of sepsis. Retrospective (N = 356) and prospective (N = 63) samples were tested from adult patients in ICU who either had the systemic inflammatory response syndrome (SIRS), or were suspected of having/diagnosed with sepsis. Patients were clinically evaluated by a panel of three expert physicians blinded to the SeptiCyte test results. Results were interpreted under either the Sepsis-2 or Sepsis-3 framework. (3) Results: Under the Sepsis-2 framework, SeptiCyte RAPID performance for the combined retrospective and prospective cohorts had Areas Under the ROC Curve (AUCs) ranging from 0.82 to 0.85, a negative predictive value of 0.91 (sensitivity 0.94) for SeptiScore Band 1 (score range 0.1–5.0; lowest risk of sepsis), and a positive predictive value of 0.81 (specificity 0.90) for SeptiScore Band 4 (score range 7.4–15; highest risk of sepsis). Performance estimates for the prospective cohort ranged from AUC 0.86–0.95. For physician-adjudicated sepsis cases that were blood culture (+) or blood, urine culture (+)(+), 43/48 (90%) of SeptiCyte scores fell in Bands 3 or 4. In multivariable analysis with up to 14 additional clinical variables, SeptiScore was the most important variable for sepsis diagnosis. A comparable performance was obtained for the majority of patients reanalyzed under the Sepsis-3 definition, although a subgroup of 16 patients was identified that was called septic under Sepsis-2 but not under Sepsis-3. (4) Conclusions: This study validates SeptiCyte RAPID for estimating sepsis probability, under both the Sepsis-2 and Sepsis-3 frameworks, for hospitalized patients on their first day of ICU admission.

Objective: The objective of this study is to report on the bactericidal effects of blue light administered at low irradiance for extended periods of time.Background: Multidrug-resistant organisms (MDROs) utilize biofilms that can limit the efficacy of antibiotics, causing infection and impaired wound healing. Unlike high-energy systems, continuous low-irradiance phototherapy (CLIP) avoids thermal injury of healthy tissue and can be delivered for extended periods.Methods: Four MDRO species, two of which contained different antibiotic resistance genes, were exposed to 405 nm irradiation in vitro. The microbes were incrementally exposed to increasing dose-rates (irradiance; mW/cm(2)) over a 24-h time period. Cell viability and biomass reduction assays were conducted to quantify the antibacterial/antibiofilm effects. Primary human dermal fibroblasts were also exposed to CLIP to assess whether these dose-rates would impair cell viability or proliferation.Results: CLIP exposure utilizing irradiances as low as 2.78 mW/cm(2) delivered over 24 h resulted in a >3.0-log (>99.9%) and >2.0-log (>99.0%) microbial load reduction when organisms were grown in planktonic and biofilm-encapsulated conditions, respectively. Crystal violet biofilm assays revealed destruction of extracellular biofilm architecture following CLIP exposure. Human fibroblast viability and proliferation were unaffected by CLIP.Conclusions: This is the first report demonstrating the antimicrobial efficacy of CLIP for MDROs found in infected wounds. CLIP did not compromise cultured human fibroblast growth and survival. This study demonstrated that very low fluence rates (irradiances) delivered over extended periods are potently antimicrobial. There is translational potential for CLIP to be fabricated as a wearable device that would enable continuous ambulatory care of wounds.

Endotoxin removal therapy with polymyxin B immobilized fiber column (PMX) has been clinically applied for sepsis and septic shock patients since 1994. The effectiveness and usefulness of this therapy have been demonstrated for more than a quarter of a century. However, a documented survival benefit has not yet been demonstrable in a large, multicenter, randomized and controlled trial. Following the findings derived from a large sepsis clinical trial with PMX in North America, a new trial is ongoing to determine if PMX has a long-term survival benefit when administered to septic patients. Another approach to support a survival benefit from intervention with PMX is to utilize a detailed analysis available from a large clinical data base. The endotoxin adsorption capacity of PMX columns in vitro and the effectiveness of PMX columns can be further demonstrable in animal models. The capability of PMX and details of its mechanism of action to intervene in the sepsis cascade and impede organ dysfunction in septic patients is not fully understood. The surface antigen expression in monocytes and neutrophils are improved after PMX therapy. Immunomodulatory effects as a result of endotoxin removal and/or other mechanisms of action have been suggested. These effects and other potential immune effects may explain some of the improved effects upon organ dysfunction of sepsis and septic shock patients. Endotoxemia may be involved in the pathophysiology of other diseases than sepsis. A rapid diagnostic method to detect and target endotoxemia could allow us to practice precision medicine and expand the clinical indications of endotoxin removal therapy.

Despite the dramatic increase in antimicrobial resistance, there is a dearth of antibiotics in development and few pharmaceutical companies working in the field. Further, any new antibiotics are likely to have a short shelf life. Ab-based interventions offer alternatives that are not likely to be circumvented by the widely prevalent antibiotic resistance genes. Bovine colostrum (BC)—the first milk after parturition, rich in nutrients and immune components—promotes gut integrity and modulates the gut microbiome. We developed a hyperimmune BC (HBC) enriched in Abs to a highly conserved LOS core region of Gram-negative bacteria by immunizing pregnant cows with a vaccine comprised of detoxified LOS from Escherichia coli O111 Rc (J5) mutant non-covalently complexed to group B meningococcal outer membrane protein (J5dLOS/OMP). This vaccine generated robust levels of anti-J5 LOS Ab in the colostrum. When given orally to neutropenic rats challenged orally with Pseudomonas aeruginosa, administration of HBC improved survival compared to non-immune rats, while both BC preparations improved survival compared to PBS controls. Elevated circulating endotoxin levels correlated with mortality. HBC and to a lesser extent non-immune BC reduced bacterial burden from the liver, lung, and spleen. We conclude that HBC and to a lesser extent BC may be effective supplements that improve outcome from lethal gut-derived disseminated infection and may reduce transmission of Gram-negative bacilli from the gastrointestinal tract.

To understand the multitude of endotoxin-mediated effects on the entire organism, it is essential that animal models be utilized in endotoxin research. Horses in many respects would be the ideal animal model for endotoxin research. One would seriously consider the use of horses in mortality endpoint experiments in endotoxin research; however, veterinary experience with endotoxin-mediated disorders in horses may provide useful insights into endotoxin effects in human diseases. Despite the numerous desirable attributes of research in nonhuman primates, there are major disadvantages, which limit the availability of these animals in endotoxin research. While such findings may well provide statistically valid data to support the claim of clinical efficacy of an experimental treatment, it should be remembered that in many animal models of endotoxin lethality, the actual dose-response lethality profiles manifest very steep slopes at the inflection point. The value and limitations of animal models in endotoxin research must be understood in the development of new therapeutic strategies in human sepsis.

We thank Eftychios Siniorakis and colleagues for their thoughtful letter on how repurposing statins and angiotensin receptor blockers (ARBs) for coronavirus disease 2019 (COVID-19) treatment might affect patients with heart failure (1). Our understanding of the pathophysiology of COVID-19 disease has advanced rapidly in the past few months. The immunological dysregulation associated with the disease and the cardiovascular effects of infection (and especially the role of angiotensin converting enzyme 2 [ACE2]) have been comprehensively reviewed (2–7). Some patients who develop acute respiratory distress syndrome (ARDS) can be severely hypoxic and yet show relatively normal pulmonary compliance (8). Endothelial dysfunction and intense inflammation seem to be important contributors to their distress (9). In addition, pulmonary microvascular coagulopathy, sometimes associated with pulmonary or systemic embolization, has added a new dimension to clinical care (10–12). Many physicians have added anticoagulation to their treatments (13). Recently, van de Veerdonk and colleagues called attention to the contribution of the kallikrein-kinin system to COVID-19-induced ARDS (14, 15). Although much attention has been focused on the relationship between the renin-angiotensin system (RAS) and COVID-19 (5–7), there is considerable cross talk between the RAS and kallikrein-kinin systems (14–16). Experimentally, a reduction in ACE2 activity can impair inactivation of the B1 bradykinin receptor and this can be associated with an increase in inflammation-induced acute lung injury (17).

Patients with COVID-19 infection are at risk of acute respiratory disease syndrome (ARDS) and death. The tissue receptor for COVID-19 is ACE2, and higher levels of ACE2 can protect against ARDS. Angiotensin receptor blockers and statins upregulate ACE2. Clinical trials are needed to determine whether this drug combination might be used to treat patients with severe COVID-19 infection.

Could the immunomodulatory drugs that have produced impressive outcomes in cancer be used to boost immunity to counter infection in the context of sepsis? Recent findings in animal models provide some support for this strategy.

The role of biomarkers for detection of sepsis has come a long way. Molecular biomarkers are taking front stage at present, but machine learning and other computational measures using bigdata sets are promising. Clinical research in sepsis is hampered by lack of specificity of the diagnosis; sepsis is a syndrome with no uniformly agreed definition. This lack of diagnostic precision means there is no gold standard for this diagnosis. The final conclusion is expert opinion, which is not bad but not perfect. Perhaps machine learning will displace expert opinion as the final and most accurate definition for sepsis.

There remains an unmet need to address the substantial morbidity and mortality associated with severe community-acquired pneumonia (sCAP). Recombinant human plasma gelsolin (rhu-pGSN) improves disease outcomes in diverse animal models of infectious and noninfectious inflammation. This blinded dose-escalation safety study involved non-intensive care unit (ICU) patients admitted for mild CAP and randomized 3:1 to receive adjunctive rhu-pGSN or placebo intravenously. Thirty-three subjects were treated: 8 in the single-dose phase and 25 in the multidose phase.

In the past 50 years, the potential benefit of corticosteroids in treating sepsis or acute respiratory distress syndrome (ARDS) has been evaluated in many randomised controlled trials (RCTs). Corticosteroids have contradictory effects on mortality, leading to a profound and still active controversy. Low doses of corticosteroids have been shown to decrease mortality from septic shock in patients who also receive mineralocorticoids.1Annane D Renault A Brun-Buisson C et al.Hydrocortisone plus fludrocortisone for adults with septic shock.N Engl J Med. 2018; 378: 809-818Crossref PubMed Scopus (548) Google Scholar However, the effect of corticosteroids has been negative in other studies.2Venkatesh B Finfer S Cohen J et al.Adjunctive glucocorticoids therapy in patients with septic shock.N Engl J Med. 2018; 378: 797-808Crossref PubMed Scopus (618) Google Scholar In one RCT,3Vilar J Ferrando C Martinez D et al.Dexamethasone treatment for ARDS: a multicentric randomized controlled trial.Lancet Respir Med. 2020; 8: 267-276Summary Full Text Full Text PDF PubMed Scopus (723) Google Scholar corticosteroids were efficacious for ARDS of various origin. This modest hope for corticosteroids has been heightened from findings in patients with severe COVID-19. Most of the initial therapeutic studies of corticosteroids for COVID-19 have been of very poor quality. The RECOVERY trial was one of the most robust studies.4The RECOVERY Collaborative GroupDexamethasone in hospitalized patients with COVID-19—preliminary report.N Engl J Med. 2020; (published online July 17.)https://doi.org/10.1056/NEJMoa2021436Crossref Scopus (7056) Google Scholar In this large, open-labelled RCT, 2104 patients treated with corticosteroids were compared with 4321 patients receiving standard therapy. The study used different compounds, at different time courses, and in patients with COVID-19 symptoms of varying severity. Corticosteroids (dexamethasone, 6 mg per day) caused a moderate but significant 11% reduction in mortality. Mortality was significantly reduced in patients who were mechanically ventilated (29%) or received oxygen (11%), but not in patients without any respiratory failure. These results were considered credible proof of corticosteroid efficacy, particularly by WHO, which announced prematurely that corticosteroid was the gold standard for treating severe COVID-19.5Lamontagne F Agoritsas T Macdonald H A living WHO guideline on drugs for COVID-19.BMJ. 2020; 370m3379Crossref PubMed Scopus (466) Google Scholar However, the methodology in this study was very questionable, in particular (but not only) because no severity markers were recorded, making highly questionable the comparability of the two treatment groups at the time of study inclusion. Results of four additional studies have since been published,6The WHO Rapid Evidence Appraisal for COVID-19 therapies (REACT) working groupAssociation between systemic corticosteroids administration and mortality among critically ill patients with Covid-19: a meta-analysis.JAMA. 2020; (published online Sept 2.)https://doi.org/10.1056/JAMAoa2021436Crossref Scopus (1679) Google Scholar, 7Dequin PF Heming N Meziani F et al.Effect of hydrocortisone on 21-day mortality or respiratory support among critically ill patients with COVID-19.JAMA. 2020; (published online Sept 2.)https://doi.org/10.1001/jama.2020.16761Crossref Scopus (334) Google Scholar, 8The Writing Committee for REMAP-CAP InvestigatorsEffect of hydrocortisone on mortality and organ support in patients with severe COVID-19.JAMA. 2020; (published online Sept 2.)https://doi.org/10.1001/jama.2020.17022Crossref Scopus (570) Google Scholar, 9Tomasini BM Maia IS Cavalcati AB et al.Effect of dexamethasone on days alive and ventilator-free in patients with moderate or severe acute respiratory distress syndrome and COVID-19: The CoDEX randomized clinical trial.JAMA. 2020; (published online Sept 2.)https://doi.org/10.1001/jama.2020.17021Crossref Scopus (865) Google Scholar one of which was a meta-analysis promoted by WHO.6The WHO Rapid Evidence Appraisal for COVID-19 therapies (REACT) working groupAssociation between systemic corticosteroids administration and mortality among critically ill patients with Covid-19: a meta-analysis.JAMA. 2020; (published online Sept 2.)https://doi.org/10.1056/JAMAoa2021436Crossref Scopus (1679) Google Scholar In this meta-analysis of pooled data from seven studies, corticosteroids were associated with a decrease in mortality from severe COVID-19. However, this effect disappeared when data from the RECOVERY trial4The RECOVERY Collaborative GroupDexamethasone in hospitalized patients with COVID-19—preliminary report.N Engl J Med. 2020; (published online July 17.)https://doi.org/10.1056/NEJMoa2021436Crossref Scopus (7056) Google Scholar were excluded from the meta-analysis, suggesting an overweight of these data in the meta-analysis. The substantial heterogeneity within the remaining six trials limits the validity of the interpretation of the meta-analysis results. Furthermore, in the RECOVERY trial,4The RECOVERY Collaborative GroupDexamethasone in hospitalized patients with COVID-19—preliminary report.N Engl J Med. 2020; (published online July 17.)https://doi.org/10.1056/NEJMoa2021436Crossref Scopus (7056) Google Scholar various compounds and dosages of corticosteroids were used. Among the three other studies,7Dequin PF Heming N Meziani F et al.Effect of hydrocortisone on 21-day mortality or respiratory support among critically ill patients with COVID-19.JAMA. 2020; (published online Sept 2.)https://doi.org/10.1001/jama.2020.16761Crossref Scopus (334) Google Scholar, 8The Writing Committee for REMAP-CAP InvestigatorsEffect of hydrocortisone on mortality and organ support in patients with severe COVID-19.JAMA. 2020; (published online Sept 2.)https://doi.org/10.1001/jama.2020.17022Crossref Scopus (570) Google Scholar, 9Tomasini BM Maia IS Cavalcati AB et al.Effect of dexamethasone on days alive and ventilator-free in patients with moderate or severe acute respiratory distress syndrome and COVID-19: The CoDEX randomized clinical trial.JAMA. 2020; (published online Sept 2.)https://doi.org/10.1001/jama.2020.17021Crossref Scopus (865) Google Scholar the CAPE COVID study7Dequin PF Heming N Meziani F et al.Effect of hydrocortisone on 21-day mortality or respiratory support among critically ill patients with COVID-19.JAMA. 2020; (published online Sept 2.)https://doi.org/10.1001/jama.2020.16761Crossref Scopus (334) Google Scholar was stopped after publication of the RECOVERY trial4The RECOVERY Collaborative GroupDexamethasone in hospitalized patients with COVID-19—preliminary report.N Engl J Med. 2020; (published online July 17.)https://doi.org/10.1056/NEJMoa2021436Crossref Scopus (7056) Google Scholar results. In CAPE COVID,7Dequin PF Heming N Meziani F et al.Effect of hydrocortisone on 21-day mortality or respiratory support among critically ill patients with COVID-19.JAMA. 2020; (published online Sept 2.)https://doi.org/10.1001/jama.2020.16761Crossref Scopus (334) Google Scholar a well designed study that enrolled 149 patients with severe COVID-19, no benefit of corticosteroids was found. In the REMAP trial,8The Writing Committee for REMAP-CAP InvestigatorsEffect of hydrocortisone on mortality and organ support in patients with severe COVID-19.JAMA. 2020; (published online Sept 2.)https://doi.org/10.1001/jama.2020.17022Crossref Scopus (570) Google Scholar which included 903 treated patients, hydrocortisone (40 mg intravenous every 6 h) significantly reduced mortality from severe COVID-19 by 26%. Although not double-blinded, REMAP was the first robust trial to show a very clear-cut positive effect on mortality. The CoDEX trial,9Tomasini BM Maia IS Cavalcati AB et al.Effect of dexamethasone on days alive and ventilator-free in patients with moderate or severe acute respiratory distress syndrome and COVID-19: The CoDEX randomized clinical trial.JAMA. 2020; (published online Sept 2.)https://doi.org/10.1001/jama.2020.17021Crossref Scopus (865) Google Scholar with an excellent methodology, included 299 patients with mild or severe ARDS. Corticosteroids significantly increased ventilator-free days during the first 28 days, but there was no benefit on 28-day mortality or length of stay in intensive care units, both tested as secondary endpoints. Finally, in Metcovid,10Jeronimo CMP Leano-Farias ME Almeida Val FF et al.Methylprednisolone as adjunctive therapy for patients hospitalized with COVID-19 (Metcovid): a randomised, double-blind, phase iib, placebo-controlled trial.Clin Infect Dis. 2020; (published online Aug 12.)https://doi.org/10.1093/cid/ciaa1177Crossref Scopus (283) Google Scholar a large phase 2b double-blind RCT with 416 patients with COVID-19, corticosteroids had no effect on mortality. The above scientific limits and the contradicting results of the various studies ought to impose caution before adoption of corticosteroids as the master drug to save lives from COVID-19 (appendix). Although the medical community and citizens worldwide are impatient for efficient therapies, enthusiasm after the first positive results should be tempered until studies with a better design are completed, demonstrating clearly the efficacy of corticosteroids. We do not think there is any equipoise or ethical problem in planning further double-blind RCTs. We declare no competing interests. Download .pdf (.1 MB) Help with pdf files Supplementary appendix

Importance:Previous research suggested that soluble human recombinant thrombomodulin may reduce mortality among patients with sepsis-associated coagulopathy.Objective:To determine the effect of human recombinant thrombomodulin vs placebo on 28-day all-cause mortality among patients with sepsis-associated coagulopathy.Design, Setting, and Participants:The SCARLET trial was a randomized, double-blind, placebo-controlled, multinational, multicenter phase 3 study conducted in intensive care units at 159 sites in 26 countries. All adult patients admitted to one of the participating intensive care units between October 2012 and March 2018 with sepsis-associated coagulopathy and concomitant cardiovascular and/or respiratory failure, defined as an international normalized ratio greater than 1.40 without other known etiology and a platelet count in the range of 30 to 150 × 109/L or a greater than 30% decrease in platelet count within 24 hours, were considered for inclusion. The final date of follow-up was February 28, 2019.Interventions:Patients with sepsis-associated coagulopathy were randomized and treated with an intravenous bolus or a 15-minute infusion of thrombomodulin (0.06 mg/kg/d [maximum, 6 mg/d]; n = 395) or matching placebo (n = 405) once daily for 6 days.Main Outcome and Measures:The primary end point was 28-day all-cause mortality.Results:Among 816 randomized patients, 800 (mean age, 60.7 years; 437 [54.6%] men) completed the study and were included in the full analysis set. In these patients, the 28-day all-cause mortality rate was not statistically significantly different between the thrombomodulin group and the placebo group (106 of 395 patients [26.8%] vs 119 of 405 patients [29.4%], respectively; P = .32). The absolute risk difference was 2.55% (95% CI, -3.68% to 8.77%). The incidence of serious major bleeding adverse events (defined as any intracranial hemorrhage; life-threatening bleeding; or bleeding event classified as serious by the investigator, with administration of at least 1440 mL [typically 6 units] of packed red blood cells over 2 consecutive days) was 23 of 396 patients (5.8%) in the thrombomodulin group and 16 of 404 (4.0%) in the placebo group.Conclusions and Relevance:Among patients with sepsis-associated coagulopathy, administration of a human recombinant thrombomodulin, compared with placebo, did not significantly reduce 28-day all-cause mortality.Trial Registration:ClinicalTrials.gov Identifier: NCT01598831.

In Gram-negative bacterial sepsis, production of excess pro-inflammatory cytokines results in hyperinflammation and tissue injury. Anti-inflammatory cytokines such as IL-10 inhibit inflammation and enhance tissue healing. Here, we report a novel approach to treat septicemia associated with intra-abdominal infection in a murine model by delicately balancing pro- and anti-inflammatory cytokines. A novel oligosaccharide compound AVR-25 selectively binds to the TLR4 protein (IC50 = 0.15 µM) in human peripheral blood monocytes and stimulates IL-10 production. Following the cecal ligation and puncture (CLP) procedure, intravenous dosing of AVR-25 (10 mg/kg, 6–12 h post-CLP) alone and in combination with antibiotic imipenem protected both young adult (10–12 week old) and aged (16–18 month old) mice against polymicrobial infection, organ dysfunction, and death. Proinflammatory cytokines (TNF-α, MIP-1, i-NOS) were decreased significantly and restoration of tissue damage was observed in all organs. A decrease in serum C-reactive protein (CRP) and bacterial colony forming unit (CFU) confirmed improved bacterial clearance. Together, these findings demonstrate the therapeutic ability of AVR-25 to mitigate the storm of inflammation and minimize tissue injury with high potential for adjunctive therapy in intra-abdominal sepsis.

The innate immune response is the rapid response system to microbial invasion. Innate immunity evolved to recognize and immediately initiate host defenses to limit damage and activate antimicrobial clearance mechanisms. The human innate immune system is highly integrated with, and coregulated by, two other critical host defense systems, the coagulation system and the adaptive immune systems. Many of the same sensing mechanisms and inflammatory signaling mechanisms in response to pathogen invasion also come into play after tissue injury and cellular necrosis. A system of receptors found primarily on myeloid cells of the innate immune system recognizes microbial threats by detecting evolutionarily conserved molecular patterns found exclusively in microbial pathogens called pathogen-associated molecular patterns (PAMPs). Similarly, injury to human cells from any cause is rapidly detectable via recognition receptors found on innate immune cells called damage-associated molecular patterns (DAMPs). Detection of either PAMPs or DAMPs signals immediate danger to the host. Innate immune responses are designed to wall off the site of injury by release of procoagulant factors for clot formation proinflammatory signals to bring phagocytes into the tissue to clear microbial invaders and begin tissue repair. The nature of these responses and the cellular mechanisms that underlie innate immunity are reviewed in this chapter.

Vascular endothelial cells demonstrate severe injury in sepsis, and a reduction in endothelial inflammation would be beneficial. Inter-α-Inhibitor (IαI) is a family of abundant plasma proteins with anti-inflammatory properties and has been investigated in human and animal sepsis with encouraging results. We hypothesized that IαI may protect endothelia from sepsis-related inflammation. IαI-deficient or sufficient mice were treated with endotoxin or underwent complement-induced lung injury. VCAM-1 and ICAM-1 expression was measured in blood and lung as marker of endothelial activation. Human endothelia were exposed to activated complement C5a with or without IαI. Blood from human sepsis patients was examined for VCAM-1 and ICAM-1 and levels were correlated with blood levels of IαI. IαI-deficient mice showed increased endothelial activation in endotoxin/sepsis- and complement-induced lung injury models. In vitro, levels of endothelial pro-inflammatory cytokines and cell growth factors induced by activated complement C5a were significantly decreased in the presence of IαI. This effect was associated with decreased ERK and NFκB activation. IαI levels were inversely associated with VCAM-1 and ICAM-1 levels in a human sepsis cohort. IαI ameliorates endothelial inflammation and may be beneficial as a treatment of sepsis.