Oral anticoagulants (OACs) reduce activated protein C (APC) plasma levels less than those of protein C (PC) in lupus erythematosus and cardiac patients. Carriers of the H1 haplotype of the endothelial PC receptor gene (PROCR) have higher APC levels than non-carriers. We aimed to confirm these results in a large group of patients treated with OACs because of venous thromboembolism (VTE) and to assess whether the effect is influenced by the PROCR H1 haplotype. We evaluated APC, PC, and factor (F)II levels in 502 VTE patients (158 with and 344 without OACs) and in 322 healthy individuals. Mean APC, PC and FII levels were significantly lower in OAC patients than in patients not taking OACs. During anticoagulant therapy, the FII/PC ratios were independent of the PC values, whereas APC/FII and APC/PC ratios significantly increased when FII and PC levels decreased. Of the 22 OAC patients carrying the H1H1genotype, 11 (50%) showed APC/PCag ≥2.0 and 10 (45%) APC/FIIag ratios ≥2.0, whereas for the 49 OAC patients non-carrying the H1 haplotype these figures were 6 (12%) and 4 (8%), respectively (p<0.001). Barium citrate adsorption of plasma from OAC patients showed that most of the circulating free and complexed APC, but only part of PCag, is fully carboxylated. In conclusion, during anticoagulant therapy VT patients have APC levels disproportionately higher than the corresponding PC levels, mainly due to the presence of the PROCR H1 haplotype. Furthermore, a sufficiently carboxylated PC Gla-domain seems to be essential for PC activation in vivo.
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http://dx.doi.org/10.1160/TH11-07-0510 | DOI Listing |
Rare bleeding disorders (RBDs) represent 3 to 5% of congenital bleeding disorders and are primarily inherited in an autosomal recessive manner, with increased prevalence in consanguineous populations. Clinically, RBDs can be accompanied by mild to severe bleeding episodes, often assessed using bleeding assessment tools (BATs) such as the International Society on Thrombosis and Hemostasis (ISTH)-BAT. However, the correlation between bleeding severity and coagulation factor activity levels remains inconsistent.
View Article and Find Full Text PDFRes Pract Thromb Haemost
October 2024
Department of Clinical Laboratory, Children's Hospital, Zhejiang University School of Medicine, National Clinical Research Center for Child Health, Hangzhou, China.
Background: Lupus anticoagulant-hypoprothrombinemia syndrome (LAHPS) is a rare acquired bleeding disorder characterized by the presence of lupus anticoagulant (LA) and acquired hypoprothrombinemia.
Objectives: To summarize the experience of diagnosis, clinical features, and treatment of lupus anticoagulant-hypoprothrombinemia syndrome (LAHPS).
Methods: A retrospective study of 70 children diagnosed with LAHPS from January 2019 to February 2024 at a single center was conducted.
J Environ Manage
November 2024
School of Economics & Finance, Xi'an Jiaotong University, Xian, 710061, China. Electronic address:
Over the last few decades, the globe has faced severe challenges in isolating entire nations from social, economic, and environmental issues. However, rising pollution levels have become the most debatable agenda. To resolve this, the world has introduced a few green initiatives, i.
View Article and Find Full Text PDFLupus
October 2024
Department of Rheumatology, Max Super Speciality Hospital, New Delhi, India.
J Thromb Haemost
November 2024
Department of Pathology and Molecular Medicine, McMaster University, Hamilton, Ontario, Canada; Division of Hematology & Thromboembolism, Department of Medicine, McMaster University, Hamilton, Ontario, Canada; Hematology, Hamilton Health Sciences, Hamilton, Ontario, Canada; Hematology, Hamilton Regional Laboratory Medicine Program, Hamilton, Ontario, Canada. Electronic address:
Background: Vitamin K (VK) deficiency (VKD) impairs γ-carboxylation of VK-dependent factors (VKDFs), resulting in higher factor (F)II levels measured by Ecarin (FIIE) reagents (that convert des-γ-carboxylated FII to meizothrombin) than by prothrombin time (FII) reagents.
Objectives: To evaluate FII/FIIE abnormalities among patients assessed for coagulopathies and identify findings predictive of coagulopathy improvement after VK.
Methods: We retrospectively assessed consecutive cases from 2002 to 2021 with FII/FIIE tests and the sensitivity and specificity of FII/FIIE ratios and FIIE-FII differences for VKD defined as international normalized ratio correction/improvement of ≥0.
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