Endothelium Modulates the Prothrombotic Phenotype of Factor V Leiden: Evidence From an Ex Vivo Model.

Background: Clinical expressivity of the thrombophilic factor V Leiden (FVL) mutation is highly variable. Recently, we demonstrated an increased APC (activated protein C) response in asymptomatic FVL carriers compared with FVL carriers with a history of venous thromboembolism (VTE) after in vivo coagulation activation. Here, we further explored this association using a recently developed ex vivo model based on patient-specific endothelial colony-forming cells (ECFCs).

Assessment of Hypercoagulability in Splanchnic Vein Thrombosis by Measurement of the Hemostasis Enzymes Thrombin and Activated Protein C.

Splanchnic vein thrombosis (SVT), which is particularly prevalent in myeloproliferative neoplasms (MPNs), has a multifactorial pathomechanism involving the anticoagulant protein C (PC) pathway. To better characterize the hypercoagulable state in SVT we assessed its key enzymes thrombin and activated PC (APC). The study population included 73 patients with SVT, thereof 36 MPN+, confirmed by bone marrow biopsy, 37 MPN-, and 30 healthy controls.

Impact of Thrombophilia Testing on Clinical Management: A Retrospective Cohort Study.

Thrombophilia management is based on the personal and family history of thrombosis. Current guidelines recommend performing thrombophilia testing only when the results will change clinical management. To investigate to what extent treatment recommendations changed following thrombophilia testing, clinical and laboratory data of 255 patients with and without venous thromboembolism who underwent thrombophilia screening were assessed retrospectively.

Loss of PHF6 causes spontaneous seizures, enlarged brain ventricles and altered transcription in the cortex of a mouse model of the Börjeson-Forssman-Lehmann intellectual disability syndrome.

Börjeson-Forssman-Lehmann syndrome (BFLS) is an X-linked intellectual disability and endocrine disorder caused by pathogenic variants of plant homeodomain finger gene 6 (PHF6). An understanding of the role of PHF6 in vivo in the development of the mammalian nervous system is required to advance our knowledge of how PHF6 mutations cause BFLS. Here, we show that PHF6 protein levels are greatly reduced in cells derived from a subset of patients with BFLS.

Decreased Protein C Pathway Activity in COVID-19 Compared to Non-COVID Sepsis: An Observational and Comparative Cohort Study.

Sepsis-associated coagulopathy increases risk of mortality. Impairment of the anticoagulant protein C (PC) pathway may contribute to the thrombotic phenotype in coronavirus disease 2019 (COVID-19) sepsis. This study assessed the functionality of this pathway in COVID-19 and non-COVID sepsis by measuring its key enzymes, thrombin and activated PC (APC).