OBJECTIVE: We seek to describe the current practice pattern use of prothrombin complex concentrate (PCC) and fibrinogen concentrate (FC) in trauma patients.
BACKGROUND: Trauma-induced coagulopathy (TIC) and endotheliopathy of trauma (EOT) contribute significantly to mortality from traumatic haemorrhage. FC, and 4-factor PCC are potential treatments for EOT and TIC, respectively.
METHODS: We obtained data from the Trauma Quality Improvement Program (TQIP) registry and identified patients who received either PCC or FC using procedural codes. We used descriptive statistics to characterise practice patterns of these products.
RESULTS: There were 6 714 002 total encounters within the TQIP from 2017 to 2022, of which 10 589 received PCC and 3009 received FC. Of the recipients, there were 35 that received both products. There were 44 that received both. The median age of PCC recipients was 77 (69-84) with 19 patients <15 years of age with the youngest being 2 years of age. There was a general upward trend in the number of facilities with documented use of PCC: 155/744, 168/766, 189/764, 206/780, 234/795, and 235/816, respectively. The median age of FC recipients was 57 (32-75) with 48 patients <15 years of age with the youngest being 1 year of age. There was a minor downward trend in the number of facilities that had documented use of FC: 55, 44, 39, 32, 38 and 40.
CONCLUSIONS: The administration of PCC and FC remains uncommon, although there appears to be an upward trend of PCC use. Most PCC use appeared to be for anticoagulation reversal in the setting of head trauma. Data guiding the use of these products are necessary as these products become more recognised as adjuncts to traumatic haemorrhage control.

Hypercoagulable states, also called thrombophilia, can either be congenital or acquired. Congenital thrombophilia, associated mainly with venous thrombosis, is either secondary to coagulation-inhibitor deficiencies, i.e., antithrombin, protein C and Protein S, or gain of function mutations, i.e., factor V Leiden and prothrombin G20210A mutations. Despite the relative frequency of these two mutations, they have not been associated with venous thrombosis recurrence. Most prevalent thrombophilia have a limited impact and usually does not change indications for duration of antithrombotic treatment or prophylaxis compared to decisions based on clinical factors. However, rare inherited thrombophilia such as antithrombin deficiency could justify a long-term anticoagulation. The main acquired thrombophilia, the Antiphospholipid syndrome (APS), is associated with both arterial and venous thrombosis. Its impact on patient management is significant: choice of the anticoagulant (DOAC vs. warfarin), duration of anticoagulation, screening of any organ involvement and systemic autoimmune disease, introduction of immunosuppressive therapy.

BACKGROUND: The purpose of the study is to examine if prolonged thromboprophylaxis decreases the risk of thrombosis after intended curative surgery for oesophageal cancer. Study results are expected to inform a guideline for thromboprophylaxis after oesophageal cancer surgery. The perspective is to reduce morbidity and mortality in this critically ill patient group. Thrombosis is the second-most common cause of cancer death after the cancer itself. The risk of thrombosis depends on the cancer type, and upper gastrointestinal cancers are considered high risk. This risk is further increased when patients undergo surgery. However, only few studies have investigated the peri- and postoperative coagulation profile in oesophageal cancer patients. Due to this lack of knowledge, prophylaxis is currently restricted to 5000 IU (international units) low-molecular weight heparin daily from surgery until discharge from hospital (approximately 10 days), whereas patients with gastric cancer receive 30 days of treatment. The present study examines whether a 30-day treatment is superior and safe, compared with the current standard treatment.
METHODS: The study is a randomised controlled trial. Inclusion is ongoing, and we aim to include 100 patients. Blood samples are drawn before and after surgery, and the coagulation is extensively examined. The primary endpoint is the difference in plasma levels of prothrombin fragment 1 + 2 (F1 + 2) 30 days after surgery between the intervention and the standard group. Furthermore, patients are examined with ultrasound to screen for asymptomatic venous thrombotic events (VTE). Secondary endpoints are incidence of bleeding, symptomatic and asymptomatic VTE and mortality 30 days 1 one year after surgery.
CONCLUSIONS: The study will provide valuable information on the perioperative coagulation profile and VTE risk of oesophageal cancer patients. The study seeks to aid in optimising the postoperative thromboprophylaxis, and the perspective is to reduce morbidity and mortality in this at-risk patient population.
BACKGROUND: The trial was prospectively registered at the EU Clinical Trials Register with ID 2021-001335-24 on 30 June 2021 and at ClinicalTrials.gov with study identifier NCT05067153.

Snake venoms are cocktails of biologically active molecules that have evolved to immobilize prey, but can also induce a severe pathology in humans that are bitten. While animal-derived polyclonal antivenoms are the primary treatment for snakebites, they often have limitations in efficacy and can cause severe adverse side effects. Building on recent efforts to develop improved antivenoms, notably through monoclonal antibodies, requires a comprehensive understanding of venom toxins. Among these toxins, snake venom metalloproteinases (SVMPs) play a pivotal role, particularly in viper envenomation, causing tissue damage, hemorrhage and coagulation disruption. One of the current challenges in the development of neutralizing monoclonal antibodies against SVMPs is the large size of the protein and the lack of existing knowledge of neutralizing epitopes. Here, we screened a synthetic human antibody library to isolate monoclonal antibodies against an SVMP from saw-scaled viper (genus Echis) venom. Upon characterization, several antibodies were identified that effectively blocked SVMP-mediated prothrombin activation. Cryo-electron microscopy revealed the structural basis of antibody-mediated neutralization, pinpointing the non-catalytic cysteine-rich domain of SVMPs as a crucial target. These findings emphasize the importance of understanding the molecular mechanisms of SVMPs to counter their toxic effects, thus advancing the development of more effective antivenoms.

The relationship between antitumor response and tumor marker changes was evaluated in patients with advanced hepatocellular carcinoma treated with durvalumab plus tremelimumab (Dur/Tre). Forty patients were enrolled in this retrospective evaluation of treatment outcomes. According to the Response Evaluation Criteria for Solid Tumors version 1.1 at 8 weeks, the objective response (OR) rate was 25% and the disease control (DC) rate was 57.5%. The median alpha-fetoprotein (AFP) ratio at 4 weeks was 0.39 in patients who achieved OR at 8 weeks (8W-OR group), significantly lower than the 1.08 in the non-8W-OR group (p = 0.0068); however, it was 1.22 in patients who did not achieve DC at 8 weeks (non-8W-DC group), significantly higher than the 0.53 in the 8W-DC group (p = 0.0006). Similarly, the median des-γ-carboxy-prothrombin (DCP) ratio at 4 weeks was 0.15 in the 8W-OR group, significantly lower than the 1.46 in the non-8W-OR group (p < 0.0001); however, it was 1.23 in the non-8W-DC group, significantly higher than the 0.49 in the 8W-DC group (p = 0.0215). Early changes in tumor markers after Dur/Tre initiation were associated with antitumor response. In particular, changes in AFP and DCP at 4 weeks may offer useful biomarkers for early prediction of both response and progressive disease following Dur/Tre.

BACKGROUND: Chronic thromboembolic pulmonary hypertension (CTEPH) and venous thromboembolism (VTE) are thought to share many common risk factors. Our study aimed to determine the frequencies of 5 thrombosis-related gene single nucleotide polymorphisms (SNPs) associated with VTE in patients with CTEPH (n 129) compared with a control group of healthy individuals without a history of VTE (n 2637).
METHODS: The SNPs of the following genes were investigated: F5 (F V Leiden, rs6025), F2 prothrombin (rs1799963), fibrinogen gamma (FGG, rs2066865), F11 (rs2289252) and ABO (non-O, rs8176719) in both groups.
RESULTS: The study found that the rs1799963 variant was more common in patients with chronic thromboembolic pulmonary hypertension (CTEPH) compared to the control group (p < .0001). The GA heterozygous variant showed a significant increase with an odds ratio (OR) of 4.480 (95% CI: 2.344-8.562) or a finding by maximum likelihood analysis (MLA) with p < .0001. Additionally, there was a notable increase in the rs8176719 variant with p < .0001 in CTEPH patients. Both the homozygous G/G variant and the heterozygous -/G variant also showed an increase, with OR of 4.2317 (95% CI: 2.45571-7.2919) and 2.4324 (95% CI: 1.46435-4.0403) respectively, or MLA (p < .0001 and p .0006). The study also revealed a higher prevalence of the heterozygous C/T variant of rs2289252 in CTEPH patients, with an OR of 1.5543 (95% CI: 1.02503-2.3568) or MLA (p .0379).
CONCLUSIONS: The study suggests that the observed gene polymorphisms F2 (rs1799963), ABO (rs8176719), and F11 (rs2289252) may play a role as independent heritable risk factors in the development of CTEPH.

Prothrombinase complex, composed of coagulation factors Xa (FXa) and Va (FVa) is a major enzyme of the blood coagulation network that produces thrombin via activation of its inactive precursor prothrombin (FII) on the surface of phospholipid membranes. However, pathways and mechanisms of prothrombinase formation and substrate delivery are still discussed. Here we designed a novel mathematical model that considered different potential pathways of FXa or FII binding (from the membrane or from solution) and analyzed the kinetics of thrombin formation in the presence of a wide range of reactants concentrations. We observed the inhibitory effect of large FVa concentrations and this effect was phospholipid concentration-dependent. We predicted that efficient FII activation occurred via formation of the ternary complex, in which FVa, FXa and FII were in the membrane-bound state. Prothrombin delivery was mostly membrane-dependent, but delivery from solution was predominant under conditions of phospholipid deficiency or FXa/FVa excess. Likewise, FXa delivery from solution was predominant in the case of FVa excess, but high FII did not switch the FXa delivery to the solution-dependent one. Additionally, the FXa delivery pathway did not depend on the phospholipid concentration, being the membrane-dependent one even in case of the phospholipid deficiency. These results suggest a flexible mechanism of prothrombinase functioning which utilizes different complex formation and even inhibitory mechanisms depending on conditions.

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BACKGROUND: All current X-ray structures of factor (F)Xa are devoid of the γ-carboxyglutamate (Gla) domain and fail to reveal the overall conformation of the free protein. The recent cryogenic electron microscopy (cryo-EM) structure of FXa in the prothrombinase complex is the only structure of full-length FXa and shows that the Gla domain is positioned at an angle relative to the epidermal growth factor 1 domain.
OBJECTIVE: Establish if the curved conformation of FXa revealed by cryo-EM is also present in solution.
METHODS: The conformation of FXa in solution was studied by single-molecule Förster resonance energy transfer.
RESULTS: The conformation of full-length FXa in solution is resolved for the first time. The conformation is curved and extremely sensitive to Ca2+. It does not differ significantly from its zymogen form or from that present in the prothrombinase complex free or bound to the physiologic substrates prothrombin and meizothrombin.
CONCLUSIONS: Measurements by single-molecule Förster resonance energy transfer reveal that FXa has a curved conformation in solution, free or bound to physiologic ligands, and validate the recent cryo-EM structures of prothrombinase. The drastic conformational changes observed in the absence of Ca2+ suggest that the structural architecture of FXa changes upon administration of vitamin K antagonists that perturb the interaction of the Gla domain with divalent cations.