Damage-Associated Molecular Patterns as Mediators of Thrombus Formation on Dialyzer Membrane in Critically Ill Patients.

This prospective study investigated the relationship between inflammation, damage-associated molecular patterns (DAMPs), and thrombus formation on dialyzer membranes in critically ill patients undergoing renal replacement therapy (RRT) from July 2020 to August 2022, identifying mechanisms and interventions to prevent clotting. The patients were divided into two groups: inflammatory (n = 56, serum C-reactive protein >10 mg/dl) and noninflammatory control (n = 45, serum C-reactive protein <5 mg/dl). Cell-free deoxyribonucleic acid (DNA) levels, high mobility group box 1 protein (HMGB1), histone H3, and myeloperoxidase (MPO) in the lumen of the hollow fiber membrane of the dialyzer were quantified. Immunostaining assessed leukocytes, fibrin fibers, and platelet thrombi on the luminal surface of the hollow fiber membrane. The inflammatory group, compared to controls, exhibited elevated cell-free DNA, HMGB1, and MPO levels, although histone H3 remained unchanged. Damage-associated molecular patterns increased with disseminated intravascular coagulation (DIC) severity. Immunostaining in the inflammatory group revealed leukocytes, amorphous nuclei, neutrophil extracellular trap-like structures, fibrin fibers, and platelet thrombi on the hollow fiber membrane's luminal surface. Elevated DAMP levels in severely inflamed patients' dialyzer membranes, correlating with DIC severity, indicate a link between inflammation, coagulation activation, and dialyzer clotting. Research into thrombus prevention in RRT for DIC-affected critically ill patients is warranted.

Efficacy of antithrombin administration for patients with sepsis: A systematic review, meta-analysis, and meta-regression.

Aims: There have been inconsistent reports regarding the effect of antithrombin on sepsis; furthermore, there are limited reports on how dosage affects therapeutic efficacy. Thus, we aimed to perform a systematic review and meta-analysis of the use of antithrombin for sepsis and a meta-regression analysis of antithrombin dosage. Methods: We included randomized controlled trials (RCTs) and observational studies of adult patients with sepsis who received antithrombin. Outcomes included all-cause mortality and serious bleeding complications. Statistical analyses and data synthesis were performed using a random-effects model; further, meta-regression and funnel plots were used to explore heterogeneity and biases. Results: Seven RCTs and six observational studies were included. Most patients in the RCTs and observational studies had severe sepsis and septic-disseminated intravascular coagulation (DIC), respectively. A meta-analysis using RCTs showed no significant differences in mortality between the antithrombin and control groups. However, the meta-analysis of observational studies indicated a trend of decreasing mortality rates with antithrombin administration (odds ratio [OR], 0.79; 95% confidence interval [CI], 0.68-0.92; p = 0.002). Bleeding complications were significantly higher in the antithrombin group than in the control group in both study types (OR, 1.90; 95% CI, 1.52-2.37; p < 0.01). The meta-regression analysis showed no correlation between antithrombin dosage and mortality. Conclusion: A meta-analysis of RCTs confirmed no survival benefit of antithrombin, whereas that of observational studies, which mostly focused on septic DIC, showed a significant beneficial effect on improving outcomes. Indications of antithrombin should be considered based on its beneficial and harmful effects.

Comparison of results obtained using clot-fibrinolysis waveform analysis and global fibrinolysis capacity assay with rotational thromboelastography.

Global fibrinolysis assays detect the fibrinolysis time of clot dissolution using tissue-type plasminogen activator (tPA). Two such assays, clot-fibrinolysis waveform analysis (CFWA) and global fibrinolysis capacity (GFC) assay, were recently developed. These were compared with rotational thromboelastography (ROTEM). Healthy donor blood samples were divided into four groups based on tPA-spiked concentrations: 0, 100, 500, and 1000 ng/mL. CFWA and GFC fibrinolysis times, including 4.1 µg/mL and 100 ng/mL tPA in the assays, were determined, denoted as CFWA-Lys and GFC-Lys, respectively. Statistical differences were recognized between tPA concentrations of 0 and 500/1000 ng/mL for CFWA-Lys, and 0 and 100/500/1000 ng/mL for GFC-Lys. The correlation coefficients with lysis onset time (LOT) of extrinsic pathway evaluation and intrinsic pathway evaluation in ROTEM were statistically significant at 0.610 and 0.590 for CFWA-Lys, and 0.939 and 0.928 for GFC-Lys, respectively (p-values < 0.0001 for all correlations). Both assays showed significant correlations with ROTEM; however, the GFC assay proved to have better agreement with ROTEM compared with the CFWA assay. These assays have the potential to reflect a hyperfibrinolysis status with high tPA concentrations.

Characterization and Usefulness of Clot-Fibrinolysis Waveform Analysis in Critical Care Patients with Enhanced or Suppressed Fibrinolysis.

INTRODUCTION: Recently, clot-fibrinolysis waveform analysis (CFWA), which is a coagulation and fibrinolysis global assay based on assessing the activated partial thromboplastin time with tissue-type plasminogen activator, was developed. This study aimed to investigate the characteristics of CFWA using plasma samples from patients in the critical care unit. MATERIALS AND METHODS: The fibrinolysis times using CFWA were measured in 298 plasma samples. These samples were divided into three groups based on the reference interval (RI) of fibrinolysis time using CFWA: shortened group, less than RI; within group, within RI; prolonged group, more than RI. The coagulation and fibrinolysis markers, including D-dimer, plasmin-α2 plasmin inhibitor complex (PIC), fibrin monomer complex (FMC), plasmin-α2 plasmin inhibitor (α2-PI), plasminogen (Plg), and fibrinogen (Fbg) were analyzed and compared among the three groups. RESULTS: The FMC level decreased in the order of shortened, within, and prolonged groups, and the decrease was statistically significant among all three group pairs. The opposite tendency was observed for Fbg and fibrinolysis-related markers of α2-PI and Plg, and significant differences were recognized in all pair comparisons except for between within and prolonged groups in Plg. The mean values of the fibrinolysis markers D-dimer and PIC in all three groups were higher than the cut-off values, and the PIC value differed significantly between the within and prolonged groups. CONCLUSION: The fibrinolysis reaction was detected in all three groups, but the status differed. CFWA has the potential to reflect the fibrinolysis status in one global assay.

Variation in coagulation factor activity levels cause discrepancies between activated partial thromboplastin time and anti-Xa activity for heparin monitoring: a retrospective observational study.

BACKGROUND: Unfractionated heparin (UFH) is primarily monitored using activated partial thromboplastin time (APTT). However, the recent introduction of anti-activated factor X (anti-Xa) activity testing has provided a direct evaluation of Xa inhibition by anticoagulants. This study aimed to investigate discrepancies between APTT and anti-Xa activity during UFH monitoring in critically ill patients and explore their underlying causes. METHODS: This study analyzed 271 pairs of laboratory test results from blood samples of 99 critically ill patients receiving continuous intravenous UFH. Theoretical APTT values were calculated using fitted curve equations from spiked sample measurements with anti-Xa activity. Samples were categorized into three groups based on the measurement of the APTT/theoretical APTT ratio: the lower group (< 80%), the concordant group (80-120%), and the upper group (> 120%). RESULTS: The overall concordance rate between APTT and anti-Xa activity was 45%, with a 55% discrepancy rate. The lower group frequently showed apparent heparin overdoses, while coagulation factor activities in the lower and upper groups were higher and lower, respectively, than those in the concordant group. Particularly, the lower group exhibited higher factor VIII activity levels than the upper and concordant groups. CONCLUSIONS: Discrepancies between APTT and anti-Xa activity were frequently observed, influenced by changes in coagulation factors activity levels. The lower and upper groups were classified as pseudo-heparin-resistant and coagulopathy types, respectively. Accurate monitoring of heparin in critically ill patients is crucial, especially in cases of pseudo-heparin resistance, where APTT values may wrongly indicate inadequate heparin dosing despite sufficient anti-Xa activity. Understanding these discrepancies is important for managing heparin therapy in critically ill patients. TRIAL REGISTRATION: Not applicable.

Multiple Retroperitoneal Abscesses Caused by Citrobacter koseri are Associated with a Poor Prognosis: A Case Report.

Citrobacter koseri causes opportunistic infections in various organs. We herein report an 84-year-old man with diabetes mellitus who presented to our hospital with left hip pain and walking difficulty. Computed tomography showed an extensive abscess with gas production, mainly in the left retroperitoneal space, caused by C. koseri infection. Despite daily cleaning of the wound and antimicrobial therapy (with surgical drainage), the patient developed repeated pneumonia and small bowel hemorrhaging caused by disseminated intravascular coagulation and died on day 65 of hospitalization. Overall, retroperitoneal abscesses caused by C. koseri are rare, and multiple abscesses may show a poor prognosis.

Differences in acute outcomes of suicide patients by psychiatric disorder: Retrospective observational study.

Suicide is a social problem with significant economic losses, the victims of which are mainly from the productive population. There are numerous reports on the assessment of suicide risk, but most focus on long-term management. Therefore, factors influencing the severity of physical impairments in the acute phase and the prognosis of suicidal patients have not been sufficiently investigated. This is a single-center retrospective observational study. We collected data on suicidal patients admitted to our emergency department. The effect of age, gender, psychiatric history, method of suicide, alcohol consumption, and hospital admission on the outcome of suicide was assessed. Outcomes were assessed using the hospital mortality scale and the cerebral performance category scale for in-hospital mortality within 28 days. Methods of suicide with a high mortality rate (hanging, jumping, carbon monoxide poisoning, and burns) were defined as lethal methods. A detailed risk assessment of outcomes was performed for patients with schizophrenia, mood disorders, and somatoform disorders. We identified 340 suicide patients from computerized medical records and analyzed 322 records without missing data. The non-survivor group predominantly comprised older adults, men, and patients without a history of psychiatric treatment. Contrastingly, more patients drank alcohol before suicide in the survivor group. In the subgroup analysis, patients with schizophrenia had unfavorable neurological outcomes. Patients with mood disorders had worse in-hospital mortality than other psychiatric patients, as did patients who chose the lethal method. By disease, patients with stress-related and somatoform disorders tended to have higher survival rates, although their psychiatric hospitalization rates were lower. Conversely, patients with mood disorders had a higher rate of hospital visits but a lower survival rate. The results suggest that usual outpatient treatment alone may not be sufficient to reduce suicide mortality in patients with mood disorders who are considered to be at high risk of suicide.

A case of plastic bronchitis with a remarkable response to steroids.

Plastic bronchitis can cause fatal airway obstruction. An 85-year-old woman with no medical history presented to the emergency department of our hospital with progressing respiratory failure and hemoptysis. Bronchoscopy revealed a fibrin-type cast thrombus in the trachea, and plastic bronchitis was diagnosed. Initial treatment involved airway thrombus removal, and the patient survived. However, bleeding persisted for 6 days, and respiratory status showed slight improvement despite ventilatory management. Steroids were administered for concomitant acute respiratory distress syndrome, and there was marked improvement in both airway hemorrhage and respiratory failure. The patient was extubated, the steroid dose was reduced, and no rebleeding was observed. The patient was discharged from the hospital 1 month after the onset of symptoms. Blood tests were positive for the myeloperoxidase-anti-neutrophil cytoplasmic antibody; however, no biopsy was performed, and no specific symptoms were observed. A definitive diagnosis was therefore not reached. The causes of plastic bronchitis are numerous, and there are no standardized diagnostic criteria or treatment guidelines for this condition. The present case suggests that steroids may be effective in some patients with plastic bronchitis.

Delayed neurologic improvement and long-term survival of patients with poor neurologic status after out-of-hospital cardiac arrest: A retrospective cohort study in Japan.

AIM: To assess survival duration and frequency of delayed neurologic improvement in patients with poor neurologic status at discharge from emergency hospitals after out-of-hospital cardiac arrest (OHCA). METHODS: This retrospective cohort study included OHCA patients admitted to two tertiary emergency hospitals in Japan between January 2014 and December 2020. Pre-hospital, tertiary emergency hospital, and post-acute care hospital data, were retrospectively collected by reviewing medical records. Neurologic improvements were defined as an improvement of Cerebral Performance Category (CPC) scores from 3 or 4 at hospital discharge to 1 or 2. The primary outcome was neurologic improvement after discharge, while the secondary outcome was survival time after cardiac arrest. RESULTS: Of all patients (n = 1,012) admitted to tertiary emergency hospitals after OHCA during the observation period, 239 with CPC 3 or 4 at discharge were included, and all were Japanese. Median age was 75 years, 64% were male, and 31% had initially shockable rhythms. Neurologic improvements were observed in nine patients (3.6%), higher in CPC 3 (31%) than CPC 4 (1.3%) patients, but not after 6 months from cardiac arrest. The median survival time after cardiac arrest was 386 days (95% confidence interval: 303-469). CONCLUSION: Survival probability in patients with CPC 3 or 4 was 50% at 1-year and 20% at 3-year. Neurologic improvements were observed in 3.6% patients, higher in CPC 3 than in CPC 4 patients. During the first 6 months after OHCA, the neurologic status may improve in patients with CPC 3 or 4.

Efficacy of Intravenous Immunoglobulins against Chronic Lymphocytic Inflammation with Pontine Perivascular Enhancement Responsive to Steroids: A Case Report.

Chronic lymphocytic inflammation with pontine perivascular enhancement responsive to steroids (CLIPPERS) is an inflammatory disease of the central nervous system that predominantly affects the brainstem. Apart from corticosteroids, there are few reported treatment options for CLIPPERS, and there is no standard therapy. A 77-year-old man presented with diplopia that had persisted for 5 months. Dysarthria and numbness of the distal right upper extremity and right lips were also observed. Brain magnetic resonance imaging (MRI) revealed a hyperintense area around the brainstem. Symptoms were relieved immediately following intravenous methylprednisolone (IVMP) administration. However, after gradual tapering of oral prednisolone to 5 mg/day, the symptoms relapsed, and brain imaging revealed that the condition had worsened. Intravenous immunoglobulins (IVIg) were administered for recurrence, with no clinical improvement. After each IVMP treatment, the patient recovered promptly. Based on the patient's symptoms and characteristic MRI findings, exclusion of other diseases, and the significant efficacy of corticosteroids, he was diagnosed with CLIPPERS. There was no recurrence at a maintenance prednisolone dose of 8 mg/day. IVIg had a poor effect on the acute phase of CLIPPERS symptoms. Compared with other immunosuppressants, IVIg is less effective in suppressing the relapse of CLIPPERS.

Gender-related differences in the coagulofibrinolytic responses and long-term outcomes in patients with isolated traumatic brain injury: A 2-center retrospective study.

Coagulation function differs by gender, with women being characterized as more hypercoagulable. Even in the early stages of trauma, women have been shown to be hypercoagulable. Several studies have also examined the relationship between gender and the prognosis of trauma patients, but no certain conclusions have been reached. Patients with isolated traumatic brain injury (iTBI) are known to have coagulopathy, but no previous studies have examined the gender differences in detail. This is a retrospective analysis of a prospective registry conducted at 2 centers. The study included adult patients with iTBI enrolled from April 2018 to March 2021. Coagulofibrinolytic markers were measured in each patient at 1 hour, 24 hours, 3 days, and 7 days after injury, and neurological outcomes were assessed with the Glasgow Outcome Scale Extended at 6 months. Subgroup analysis was also performed by categorizing patients into groups according to neurological prognosis or age at 50 years. Males (n = 31) and females (n = 21) were included in the analysis. In males, there was a significant difference in the levels of activated partial thromboplastin time (P = .007), fibrin/fibrinogen degradation products (P = .025), D-dimer (P = .034), α2-plasmin inhibitor (P = .030), plasmin-α2-plasmin inhibitor complex (P = .004) at 1 hour after injury between favorable and unfavorable long-term neurological outcome groups, while in females there was no significant difference in these markers between 2 groups. In the age group under 50 years, there were significant gender differences in fibrinogen (day 3: P = .018), fibrin/fibrinogen degradation products (1 hour: P = .037, day 3: P = .009, day 7: P = .037), D-dimer (day 3: P = .005, day 7: P = .010), plasminogen (day 3: P = .032, day 7: P = .032), and plasmin-α2-plasmin inhibitor complex (day 3: P = .001, day 7: P = .001), and these differences were not evident in the age group over 50 years. There were differences in coagulofibrinolytic markers depending on gender in patients with iTBI. In male patients, aggravation of coagulofibrinolytic markers immediately after traumatic brain injury may be associated with poor neurologic outcome 6 months after injury.

Neutrophil phenotypes implicated in the pathophysiology of post-traumatic sepsis.

Background: The disruption of immune homeostasis after trauma is a major cause of post-traumatic organ dysfunction and/or sepsis. Recently, a variety of neutrophil phenotypes with distinct functions have been identified and suggested as involved in various clinical conditions. The association between neutrophil phenotypes and post-traumatic immunodeficiency has also been reported, yet the specific neutrophil phenotypes and their functional significance in post-traumatic sepsis have not been fully clarified. Therefore, we sought to investigate neutrophil phenotypic changes in a murine model, as these may hold prognostic value in post-traumatic sepsis. Materials and methods: Third-degree burns affecting 25% of the body surface area were used to establish trauma model, and sepsis was induced 24 h later through cecal ligation and puncture (CLP). The Burn/CLP post-traumatic sepsis model and the Sham/CLP control model were established to assess the immunological status after trauma. Histopathological evaluation was performed on the spleen, liver, kidneys, and lung tissues. Immunological evaluation included the assessment of neutrophil markers using mass cytometry as well as cytokine measurements in serum and ascitic fluid through multiplex analysis using LUMINEX®. Results: The Burn/CLP group had a lower survival rate than the Sham/CLP group. Histopathological examination revealed an impaired immune response and more advanced organ damage in the Burn/CLP group. Furthermore, the Burn/CLP group exhibited higher levels of transforming growth factor-beta 1 in the blood and generally lower levels of cytokines than the Sham/CLP group. CD11b, which is involved in neutrophil adhesion and migration, was highly expressed on neutrophils in the Burn/CLP group. The expression of CD172a, which is related to the inhibition of phagocytosis, was also upregulated on neutrophils in the Burn/CLP group. The expression of sialic acid-binding lg-like lectin F and CD68 also differed between the two groups. Conclusion: Different neutrophil phenotypes were observed between Burn/CLP and Sham/CLP groups, suggesting that neutrophils are implicated in the immune imbalance following trauma. However, further studies are needed to prove the causal relationships between neutrophil phenotypes and outcomes, including survival rate and organ dysfunction.

Effect of annual hospital admissions of out-of-hospital cardiac arrest patients on prognosis following cardiac arrest.

BACKGROUND: Although the prognosis of patients treated at specialized facilities has improved, the relationship between the number of patients treated at hospitals and prognosis is controversial and lacks constancy in those with out-of-hospital cardiac arrest (OHCA). This study aimed to clarify the effect of annual hospital admissions on the prognosis of adult patients with OHCA by analyzing a large cohort. METHODS: The effect of annual hospital admissions on patient prognosis was analyzed retrospectively using data from the Japanese Association for Acute Medicine OHCA registry, a nationwide multihospital prospective database. This study analyzed 3632 of 35,754 patients hospitalized for OHCA of cardiac origin at 86 hospitals. The hospitals were divided into tertiles based on the volume of annual admissions. The effect of hospital volume on prognosis was analyzed using logistic regression analysis with multiple imputation. Furthermore, three subgroup analyses were performed for patients with return of spontaneous circulation (ROSC) before arrival at the emergency department, patients admitted to critical care medical centers, and patients admitted to extracorporeal membrane oxygenation-capable hospitals. RESULTS: Favorable neurological outcomes 30 days after OHCA for patients overall showed no advantage for medium- and high-volume centers over low-volume centers; Odds ratio (OR) 0.989, (95% Confidence interval [CI] 0.562-1.741), OR 1.504 (95% CI 0.919-2.463), respectively. However, the frequency of favorable neurological outcomes in OHCA patients with ROSC before arrival at the emergency department at high-volume centers was higher than those at low-volume centers (OR 1.955, 95% CI 1.033-3.851). CONCLUSION: Hospital volume did not significantly affect the prognosis of adult patients with OHCA. However, transport to a high-volume hospital may improve the neurological prognosis in OHCA patients with ROSC before arrival at the emergency department.

Association of Histones With Coagulofibrinolytic Responses and Organ Dysfunction in Adult Post-cardiac Arrest Syndrome.

Background: Patients successfully resuscitated from cardiac arrest often develop organ dysfunction caused by systemic inflammation and increased coagulation, leading to disseminated intravascular coagulation (DIC). The involvement of histones in DIC and organ dysfunction in patients with sepsis and trauma has been previously reported, raising the probability that histones may also be associated with pathophysiology in patients after cardiac arrest and resuscitation. This study evaluated the relationship between histones and organ dysfunction related to coagulofibrinolytic changes in patients with post-cardiac arrest syndrome (PCAS). Methods: This prospective single-center observational study assessed 35 adult patients with PCAS who were divided into two groups, i.e., 15 patients with multiple organ dysfunction syndrome (MODS) and 20 patients without MODS. MODS was defined as a sequential organ failure assessment score of ≥12. The plasma levels of histones and coagulofibrinolytic markers, including soluble fibrin, tissue-type plasminogen activator, plasminogen activator inhibitor-1, plasmin-alpha 2-plasmin inhibitor complex (PIC), and soluble thrombomodulin, were measured in patients with PCAS immediately after admission to the emergency department, and 3 and 24 h after arriving at the hospital. Results: PCAS patients with MODS had higher DIC scores [4 (3.0-5.0) vs. 1 (0.0-3.0), p = 0.012] and higher mortality rates (66.7% vs. 20.0%, p = 0.013) than those without MODS. Moreover, patients with MODS exhibited higher histone levels than those without MODS during the early phase of the post-resuscitation period. Severe endothelial injury and higher thrombin and plasmin generation were observed in the MODS group. Plasma levels of histones were positively correlated with those of soluble fibrin immediately after resuscitation (rho = 0.367, p = 0.030) and PIC 3 h after arriving at the hospital (rho = 0.480, p = 0.005). This correlation was prominent in the patient population with MODS (soluble fibrin: rho = 0.681, p = 0.005, PIC: rho = 0.742, p = 0.002). Conclusions: This study demonstrated that elevated histone levels were associated with increased levels of thrombin, and subsequent plasmin generation in PCAS patients, especially those with MODS. Further studies are required to elucidate the causal relationship between histones and organ dysfunction related to DIC in PCAS.

Protocol for a Sepsis Model Utilizing Fecal Suspension in Mice: Fecal Suspension Intraperitoneal Injection Model.

Background: Various animal models of sepsis have been developed to optimize sepsis treatment. However, therapeutic agents that were successful in animal models were rarely effective in human clinical trials. The cecal ligation and puncture (CLP) model is currently the gold standard for sepsis studies. However, its limitations include the high variability among researchers and the difficulty in comparing animals with different cecum shapes and sizes. In this study, we established a protocol for the creation of a simple and accessible sepsis rodent model using fecal suspensions that minimized differences in technical effects among researchers and individual differences in animals. Methods: A mouse model of sepsis using fecal suspension intraperitoneal injection (FSI) was created using fresh stool excreted within 24 h. The collected fresh stool was dissolved in saline solution and filtered. The obtained fecal suspension was injected intraperitoneally into the mice. Moreover, fecal suspensions with different concentrations were prepared, and the survival rates were compared among the fecal suspensions for each concentration. To assess the validity of the FSI as a sepsis model, CLP and FSI with similar mortality rates were compared pathologically, physiologically, immunologically, and bacteriologically. Histopathological comparison was evaluated by hematoxylin-eosin and Gram staining of the parenchymal organs. Physiological evaluation was performed by comparing the respiratory rate, body temperature, and blood gas analysis results. Immunological assessment was performed using multiplex analysis. Bacteriological comparisons were performed by culturing ascites fluid. Results: The FSI model increased mortality in proportion to the fecal suspension concentration. The mortality rate was reduced with antibiotic administration. In various comparative experiments conducted using the FSI and CLP models, both models showed findings consistent with sepsis. Furthermore, the FSI model showed less variability among the individuals in each test. Conclusion: This is the first detailed and accurate report of a protocol for creating a sepsis model using fecal suspension. The FSI model is a minimally invasive and accessible sepsis rodent model. Its clinical validity as a sepsis model was proven via histological, physiological, microbiological, and immunological evaluation methods. The FSI model minimizes individual differences between mice and helps to conduct accurate studies after the onset of sepsis.

Thrombin generation capacity is enhanced by low antithrombin activity and depends on the activity of the related coagulation factors.

BACKGROUND: Supplementation with antithrombin (AT) concentrates is now common in the treatment of congenital and acquired AT deficiency. However, there is no established consensus on the target and timing of supplementation. We aimed to elucidate the effects of AT deficiency on the balance between coagulation activation and inhibition using a thrombin generation assay as in vitro global assay. METHODS: Samples were prepared by admixing commercially acquired AT-deficient plasma with < 1% AT activity with pooled normal plasma. The AT activity in each sample was adjusted to 100, 90, 70, 50, 40, 30, 10, 5, and < 1%. A thrombin generation assay was performed in each sample. AT concentrate-spiked samples were also prepared by adjusting the AT activities in four types of the concentrates: one recombinant and three plasma-derived AT concentrates. The final targeted AT activities in the samples were adjusted to 100, 50, 30, and 5% by spiking each concentrate into the AT-deficient plasma. We also prepared samples with five levels of prothrombin time (PT) % in coagulation factors with the AT activity fixed at 30% by dilution by mixing AT-deficient plasma and normal plasma with Owren's veronal buffer to adjust the coagulation factor activities in several proportions. The theoretical target PT% values were 100, 66, 50, 40, and 30%. A thrombin generation assay was performed on all samples. RESULTS: The ability to generate thrombin depended on the AT activity, and the amount of thrombin generation was increased as AT was decreased. Additionally, the amount of thrombin generation was changed significantly when AT activity was ≤ 50%, indicating that AT suppressed thrombin generation. In particular, thrombin generation was remarkable when AT activity was < 30%, and it can be assumed that the prognosis is poor due to organ failure from thrombotic tendency. CONCLUSIONS: The results presented in this basic research were found to be consistent with the clinical findings to date. The mechanism by which 30-50% of AT activity is set as the clinical boundary was elucidated by the thrombin generation assay.

Fibrinolytic system activation immediately following trauma was quickly and intensely suppressed in a rat model of severe blunt trauma.

In severe trauma, excessive fibrinolytic activation is associated with an increase in the transfusion volume and mortality rate. However, in the first several hours after a blunt trauma, changes in fibrinolytic activation, suppression, and activation-suppression balance have not yet been elucidated, which the present study aimed to clarify. Anesthetized 9-week-old male Wistar S/T rats experienced severe blunt trauma while being placed inside the Noble-Collip drum. Rats were randomly divided into four groups of seven. The no-trauma group was not exposed to any trauma; the remaining groups were analysed 0, 60, and 180 min after trauma. Immediately following trauma, total tissue-plasminogen activator (tPA) levels significantly increased in the plasma, and the balance of active tPA and active plasminogen activator inhibitor-1 (PAI-1) significantly tipped toward fibrinolytic activation. After trauma, both tPA and PAI-1 levels increased gradually in various organs and active and total PAI-1 levels increased exponentially in the plasma. Total plasma tPA levels 60 min after trauma returned quickly to levels comparable to those in the no-trauma group. In conclusion, fibrinolytic activation was observed only immediately following trauma. Therefore, immediately after trauma, the fibrinolytic system was activated; however, its activation was quickly and intensely suppressed.