Acclimatized Lowlanders Exhibit a Hypocoagulable Profile after a Passive Ascent at High Altitude.

Stauffer, Emeric, François Caton, Raphael Marlu, Aurélien Pichon, Landry Seyve, Michael Furian, Aymeric Paillisser, Florence Berquet, Jeremy De Abreu, Blandine Deschamps, Benoit Polack, Philippe Connes, Paul Robach, Stéphane Doutreleau, Julien V Brugniaux, Samuel Verges, and Benoit Champigneulle.Acclimatized lowlanders exhibit a hypocoagulable profile after a passive ascent at high altitude. 00:00-00, 2024.

Are coagulation profiles in Andean highlanders with excessive erythrocytosis favouring hypercoagulability?

Chronic mountain sickness is a maladaptive syndrome that affects individuals living permanently at high altitude and is characterized primarily by excessive erythrocytosis (EE). Recent results concerning the impact of EE in Andean highlanders on clotting and the possible promotion of hypercoagulability, which can lead to thrombosis, were contradictory. We assessed the coagulation profiles of Andeans highlanders with and without excessive erythrocytosis (EE+ and EE-).

Toward non-factor therapy in hemophilia: an antithrombin insensitive Gla-domainless factor Xa as tissue factor pathway inhibitor bait.

Background: Gla-domainless factor (F) Xa (GD-FXa) was proposed as a trap to endogenous anticoagulant tissue factor pathway inhibitor (TFPI) to restore thrombin generation in hemophilia. Using computational chemistry and experimental approaches, we previously showed that S195A GD-FXa also binds TFPI and restores coagulation in plasma obtained from person(s) with hemophilia.

Methods: To design a GD-FXa variant with improved anti-TFPI affinity, we performed molecular dynamics simulations and identified suitable sites for mutagenesis.

Lack of the human choline transporter-like protein SLC44A2 causes hearing impairment and a rare red blood phenotype.

Blood phenotypes are defined by the presence or absence of specific blood group antigens at the red blood cell (RBC) surface, due to genetic polymorphisms among individuals. The recent development of genomic and proteomic approaches enabled the characterization of several enigmatic antigens. The choline transporter-like protein CTL2 encoded by the SLC44A2 gene plays an important role in platelet aggregation and neutrophil activation.

How to improve clotting factors depletion in double-filtration plasmapheresis.

Background: Double-filtration plasmapheresis (DFPP), a selective therapeutic apheresis, can deplete pathogenic antibodies/substances, but also important coagulation factors.

Aim: To determine if the use of a separator filter with different characteristics (CascadefloEC-50 W) as compared to the reference filter (PlasmafloOP-08 W) is as efficient in terms of immunoglobulin loss, but can reduce coagulation factor losses and have similar tolerability.

Patients/methods: This is a single-center prospective study including 14 patients divided into two groups (7 each): that is, group1 = CascadefloEC-50 W and group2 = PlasmafloOP-08 W.

Effect of immunoadsorption alone or combined with membrane filtration on hemostasis parameters.

Introduction: ABO- or HLA-incompatible kidney transplantation is possible thanks to pretransplant antibody-depletion achieved by extracorporeal-treatment modalities. These methods induce depletion of some plasma proteins and may also impact on proteins involved in hemostasis.

Methods: To determine the impact of one session of immunoadsorption (IA) alone or combined with membrane filtration (MF) on clotting factors and natural anticoagulants, we performed a prospective, observational study on 13 patients waiting for HLA-/ABO-incompatible kidney transplants.

Aggregates Dramatically Alter Fibrin Ultrastructure.

Among the many factors influencing fibrin formation and structure (concentration, temperature, composition, pH, etc.), it has been suggested that the polydispersity of fibrinogen may play an important role. We propose here a detailed investigation of the influence of this parameter on fibrin multiscale structure.

Fibrinography: A Multiwavelength Light-Scattering Assay of Fibrin Structure.

We have previously developed a fibrin structural assay dedicated to purified fibrinogen-thrombin system. Here, we extend the pertinence of this test, called Fibrinography, to tissue factor-triggered plasma coagulation. We show that Fibrinography determines quantitatively the structure of fibrin fibers in plasma with an excellent reproducibility.

The influence of coagulation on the drying dynamics of blood pools.

Little is currently known about the importance of clotting during the drying of blood pools. While this is of little moment for droplets where drying occurs faster than contact-phase-induced clotting, clotting may significantly influence blood pools drying as it transform a liquid into a gel. To investigate this influence, we compare the drying of citrated and unmodified blood pools at constant haematocrit, showing large morphological differences during drying, both in the surface appearance, in the colour lightness, as well as in the generation and location of cracks.

Tumor microenvironment and clonal monocytes from chronic myelomonocytic leukemia induce a procoagulant climate.

Chronic myelomonocytic leukemia (CMML) is a myeloid hematological malignancy with overlapping features of myelodysplastic syndromes (MDSs) and myeloproliferative neoplasms (MPNs). The knowledge of the role of the tumor microenvironment (TME), particularly mesenchymal stromal cells (MSCs), in MDS pathogenesis is increasing. Generally, cancer is associated with a procoagulant state participating in tumor development.

Reducing Fibrinogen and Factor XIII Using Double-Filtration Plasmapheresis for Antibody-Mediated Rejection: Predictive Models.

Background/aims: Antibody-mediated rejection (AMR) is related to circulating donor-specific anti-human leukocyte antigen alloantibodies (DSAs). DSAs can be removed by apheresis, for example, double-filtration plasmapheresis (DFPP). However, DFPP removes some clotting factors (fibrinogen and factor XIII [FXIII]).