Circulating histone H3 levels in septic patients are associated with coagulopathy, multiple organ failure, and death: a single-center observational study

Abstract Background Nuclear histone proteins are released into the extracellular space, and act as major mediators of coagulopathy and remote organ failure in septic animals. However, the circulating histone levels in septic patients have not been precisely quantified. Methods Using a novel enzyme-linked immunosorbent assay for histone H3 detection, we measured the serum histone H3 levels in 85 patients admitted to the intensive care unit because of infectious diseases. We then evaluated the associations of circulating histone H3 levels with organ failure, coagulopathy, and mortality. Results Circulating histone H3 levels were significantly higher in patients with coagulopathy, and were positively correlated with numbers of organ failures. Circulating histone H3 levels were also associated with fatal outcome. Receiver-operating characteristic analyses revealed that the predictive performance of circulating histone H3 levels for mortality was higher than that of conventional inflammatory markers, including white blood cell count, C-reactive protein, and cell-free DNA. Conclusions Circulating histone H3 levels are associated with coagulopathy, multiple organ failure, and death in patients requiring intensive care because of infectious diseases

Damage-associated molecular patterns and fibrinolysis perturbation are associated with lethal outcomes in traumatic injury

Abstract Background Upon cellular injury, damage-associated molecular patterns (DAMPs) are released into the extracellular space and evoke proinflammatory and prothrombotic responses in animal models of sterile inflammation. However, in clinical settings, the dynamics of DAMP levels after trauma and links between DAMPs and trauma-associated coagulopathy remain largely undetermined. Methods Thirty-one patients with severe trauma, who were transferred to Kagoshima City Hospital between June 2018 and December 2019, were consecutively enrolled in this study. Blood samples were taken at the time of delivery, and 6 and 12 h after the injury, and once daily thereafter. The time-dependent changes of coagulation/fibrinolysis markers, including thrombin-antithrombin complex, α2-plasmin inhibitor (α2-PI), plasmin-α2-PI complex, and plasminogen activator inhibitor-1 (PAI-1), and DAMPs, including high mobility group box 1 and histone H3, were analyzed. The relationship between coagulation/fibrinolysis markers, DAMPs, Injury Severity Score, in-hospital death, and amount of blood transfusion were analyzed. Results The activation of coagulation/fibrinolysis pathways was evident at the time of delivery. In contrast, PAI-1 levels remained low at the time of delivery, and then were elevated at 6–12 h after traumatic injury. Histone H3 and high mobility group box 1 levels were elevated at admission, and gradually subsided over time. PAI-1 levels at 6 h were associated with serum histone H3 levels at admission. Increased histone H3 levels and plasmin-α2-PI complex levels were associated with in-hospital mortality. α2-PI levels at admission showed the strongest negative correlation with the amount of blood transfusion. Conclusion The elevation of histone H3 levels and fibrinolysis perturbation are associated with fatal outcomes in patients with traumatic injury. Patients with low α2-PI levels at admission tend to require blood transfusion

Circulating histone H3 levels are increased in septic mice in a neutrophil-dependent manner: preclinical evaluation of a novel sandwich ELISA for histone H3

Abstract Background Nuclear histone proteins are released into the extracellular space during sepsis and act as major mediators of death. However, circulating histone levels have not been precisely quantified. Methods We developed a novel enzyme-linked immunosorbent assay (ELISA) for detection of circulating histone H3 levels and evaluated its performance. Using the ELISA, we measured plasma histone H3 levels in C57BL/6 J mice subjected to cecal ligation and puncture (CLP)-induced sepsis. Results The newly developed ELISA enabled reproducible measurement of histone H3 levels with a working range up to 250 ng/mL. Using the ELISA, we found that plasma histone H3 levels were elevated in septic mice compared with sham-operated mice (p < 0.01). The elevation of histone H3 levels was abrogated when neutrophils were depleted (p < 0.01). Conclusions Our novel ELISA provides reproducible measurements of histone H3 levels. Circulating histone H3 levels are increased in septic mice in a neutrophil-dependent manner. Further studies are needed to evaluate the clinical utility of histone H3 levels in patients with sepsis

Edaravone, a Synthetic Free Radical Scavenger, Enhances Alteplase-Mediated Thrombolysis

The combination of alteplase, a recombinant tissue plasminogen activator, and edaravone, an antioxidant, reportedly enhances recanalization after acute ischemic stroke. We examined the influence of edaravone on the thrombolytic efficacy of alteplase by measuring thrombolysis using a newly developed microchip-based flow-chamber assay. Rat models of embolic cerebral ischemia were treated with either alteplase or alteplase-edaravone combination therapy. The combination therapy significantly reduced the infarct volume and improved neurological deficits. Human blood samples from healthy volunteers were exposed to edaravone, alteplase, or a combination of alteplase and edaravone or hydrogen peroxide. Whole blood was perfused over a collagen- and thromboplastin-coated microchip; capillary occlusion was monitored with a video microscope and flow-pressure sensor. The area under the curve (extent of thrombogenesis or thrombolysis) at 30 minutes was 69.9% lower in the edaravone-alteplase- than alteplase-treated group. The thrombolytic effect of alteplase was significantly attenuated in the presence of hydrogen peroxide, suggesting that oxidative stress might hinder thrombolysis. D-dimers were measured to evaluate these effects in human platelet-poor plasma samples. Although hydrogen peroxide significantly decreased the elevation of D-dimers by alteplase, edaravone significantly inhibited the decrease. Edaravone enhances alteplase-mediated thrombolysis, likely by preventing oxidative stress, which inhibits fibrinolysis by alteplase in thrombi