Thromb Haemostasis
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Comparative Study
Point-of-care testing of the international normalized ratio in patients with antiphospholipid antibodies.
Antiphospholipid antibodies can influence the results of clotting tests in a subset of patients, which can be a major obstacle in monitoring warfarin. The aim was to determine if point-of-care testing of the International Normalized Ratio (INR) is influenced by antiphospholipid antibodies. We compared 59 patients receiving warfarin for a diagnosis of antiphospholipid antibody syndrome (APS) to 49 patients receiving warfarin for atrial fibrillation to evaluate the consistency between INR results obtained by different methods. ⋯ The differences were similar for patients with APS and atrial fibrillation for all INR comparisons with the exception of the plasma-based method compared with the ProTime, which showed a mean absolute difference of 0.4 +/- 0.3 for APS patients and of 0.2 +/- 0.2 for atrial fibrillation patients (p = 0.02). In a subset ofAPS patients, the ProTime system will not yield an INR result and the HEMochron Signature (citrate and non-citrate whole-blood) INR results will exhibit elevated INR results. For this subset of APS patients, we suggest using an alternative method to monitor warfarin.
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Clinical Trial
The effects of supra-normal protein C levels on markers of coagulation, fibrinolysis and inflammation in a human model of endotoxemia.
The protein C pathway serves as a modulating system with both anti-inflammatory and anticoagulant properties and is intimately involved in the pathophysiology of inflammation and sepsis. Treatment with recombinant human activated protein C (rhAPC) can reduce the mortality of severe sepsis. We investigated whether an elevation of plasma protein C levels to supra-normal levels by infusion of a protein C zymogen concentrate has an effect on coagulation, protein C activation or inflammation in a human endotoxemia model. ⋯ Infusion of protein C zymogen was safe and no adverse effects occurred. The increase of protein C levels several fold above the normal range resulted in a proportional increase of the APC levels, but had no major anticoagulant, anti-inflammatory or profibrinolytic effects. Low grade endotoxemia itself induces significant protein C activation, which correlates with the TNF release.
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Clinical Trial
The effect of long-term, low-dose tranexamic acid treatment on platelet dysfunction and haemoglobin levels in haemodialysis patients.
Some previous studies suggest that activation of the fibrinolytic system may induce platelet dysfunction in haemodialysis patients. Accordingly, inhibition of fibrinolysis may improve platelet dysfunction, and speculatively increase haemoglobin levels. We tested this hypothesis. ⋯ No complications in terms of arterial or venous thrombosis were observed. Our pilot study suggests that long-term, low-dose TXA treatment of haemodialysis patients with substantially prolonged in vitro closure time results in a significant improvement of platelet dysfunction and a significant increase in haemoglobin values. These new, promising results merit further investigation in larger studies.