Calcium Prevents Enhanced Degradation of Factor VIII in the Condition of Motion.

Background: Hemophilia A and B induce recurrent bleeding episodes, mainly in skeletal muscles and joints that are in intermittent motion. We have previously demonstrated that intermittent motion contributes to increased degradation of factors VIII and IX. Objectives: Given that calcium ions are known to enhance factor VIII-von Willebrand factor (vWF) interaction, the present study has investigated the role of these ions on factors VIII and IX in the condition of motion. Methods: The effects of calcium ions were assessed using purified proteins via Western blot, factor VIII activity, immunocytochemistry, and in Institute of Cancer Research (ICR) mice with no specific genetic background. Results: Calcium was found to prevent degradation of plasma-derived factor VIII but not that of factor IX, during intermittent motion. Calcium levels in the microcirculation of mouse striated muscles were elevated following movement, enabling prevention of factor VIII degradation in normal physiology. Calcium supplementation in drinking water increased factor VIII levels in blood and striated muscles of ICR mice during movement. Conclusions: calcium ions decrease factor VIII degradation in the condition of motion. Further research on the impact of calcium salt oral supplementation on hemophilia patients is warranted.

An outbreak of severe coagulopathy in northern Israel among users of illicit synthetic cannabinoids adulterated with brodifacoum.

INTRODUCTION: Adulteration of illicit drugs is a well-known phenomenon that may expose consumers to unexpected adverse effects. We report a large outbreak of severe coagulopathy in northern Israel during nine months in 2021-2022 among users of synthetic cannabinoids adulterated with a long-acting anticoagulant, brodifacoum. METHODS: We performed a retrospective cohort study based on data extracted from the Israeli National Poison Information Center database and from electronic medical patient records at three participating hospitals. Confiscated drug samples and blood samples obtained at admission in a subgroup of patients were tested for the presence of long-acting anticoagulants. RESULTS: We identified 98 patients affected by the outbreak. All patients had a prolonged international normalized ratio on admission, and in 69%, the blood was non-coagulating. For patients treated in the three participating centers (n = 72), the presenting complaint was overt bleeding in 79% of patients, most commonly in the urinary (53%) and gastrointestinal tracts (50%). The most severe complications were intracranial bleeding (4%), hemothorax (3%), pericardial bleeding (1%), and four patients died. Brodifacoum was detected in all available blood samples (median concentration 207 µg/L, interquartile range 112-349 µg/L, range 45-1,118 µg/L), and the drug samples contained both brodifacoum and the synthetic cannabinoid ADB-BUTINACA. All patients were treated with high-dose phytomenadione (vitamin K1) and additionally by packed red blood cell transfusions, fresh frozen plasma, and/or 4-factor prothrombin complex concentrate when indicated. The most frequent phytomenadione (vitamin K1) dose regimen was initially 20 mg intravenously every eight hours, and at discharge, 20 mg orally three times daily. CONCLUSIONS: Outbreaks of severe coagulopathies in users of synthetic cannabinoids adulterated with a long-acting anticoagulant continue to erupt in different regions of the world. Rapid recognition of an outbreak requires a high index of suspicion when confronting young, otherwise healthy subjects with otherwise unexplained severe coagulopathy.

Heparanase procoagulant activity is elevated in women using oral contraceptives.

STUDY QUESTION: What is the effect of estrogen on heparanase procogulant activity? SUMMARY ANSWER: Estrogen increases heparanase procoagulant activity. WHAT IS KNOWN ALREADY: Estrogen therapy increases the risk of thrombosis and was previously found to up-regulate heparanase expression. Heparanase is involved in angiogenesis and metastasis, and has been shown to form a complex with tissue factor (TF) and also shown to enhance the generation of factor Xa. STUDY DESIGN, SIZE, DURATION: A case-control study. Thirty-four healthy women using oral contraceptives (OC) and 41 women not using hormonal therapy and not pregnant per history were enrolled, over a 5-month period, at the Rambam Medical Center, Haifa, Israel. In vitro, estrogen receptor-positive (MCF-7) and -negative (MDA-231) cell lines were incubated with estrogen, tamoxifen and ICI-182.780 a pure estrogen receptor antagonist. The cell medium was evaluated for TF/heparanase complex activity, TF activity and heparanase procoagulant activity by chromogenic substrate. PARTICIPANTS/MATERIALS, SETTING, METHODS: Exclusion criteria included age <18 years, post-menopausal women, concomitant medications other than supplement minerals and vitamins, acute or chronic illness. MAIN RESULTS AND THE ROLE OF CHANCE: The study demonstrates increased risk of high heparanase procoagulant activity in OC users. When a cutoff level of 0.25 (absorbance 405-490 nm) was set, the odds ratio was 131 (P < 0.0001). When all results were studied by quartiles, in quartiles 3 and 4 the results were almost exclusively of the OC users (P < 0.0001). In cell cultures, estrogen and tamoxifen increased heparanase procoagulant activity in the medium of estrogen receptor-positive (MCF-7) cells. LIMITATIONS, REASONS FOR CAUTION: The main limitation of the current study is that the two estrogens given to the women and cell cultures, ethinyl estradiol (EE) and 17-ß-estradiol (E2), respectively, may have different effects on the coagulation system, although an increase in heparanase procoagulant activity was demonstrated in both of them. Although the sample size of the study group was limited, significant differences in the activation of the extrinsic coagulation pathway were demonstrated. WIDER IMPLICATIONS OF THE FINDINGS: The clinical relevance of the heparanase procoagulant activity assay as a screening tool in thrombophilia work-up should further be elucidated.