Exercise and hypoxia-induced hypercoagulability is counterbalanced in women in part by decreased platelet reactivity

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. High Alt Med Biol. 00:00-00, 2024. Background: Discordant results have been previously reported regarding the impact of high-altitude (HA) exposure on coagulation. We aimed to investigate changes in coagulation parameters in lowlanders exposed to HA for 14 days using a combination of dynamic coagulation assays and conventional in vitro tests. Material and Methods: We assessed coagulation in 10 lowlanders using whole-blood rotational thromboelastometry (ROTEM), thrombin generation assay (TGA) on poor-platelet plasma, and conventional coagulation tests. Tests were performed at low altitude (LA, 210 m) and at the end of a 14-day sojourn at HA, including passive ascents to 3,800 m for 6 days and then to 5,100 m for 8 days. Results: Conventional tests revealed significant changes in coagulation factors and inhibitors after HA exposure, although these changes remained within normal ranges. ROTEM assays demonstrated a delayed clot initiation in EXTEM/FIBTEM, without any alteration in clot firmness, in HA versus LA (p < 0.01). TGA changes showed an increase in time to peak (p < 0.01), a decrease in endogenous thrombin potential (p < 0.05), and a decrease in thrombin peak (p < 0.001). Conclusions: We found no evidence of hypercoagulability in lowlanders after a 14-day sojourn at HA. In contrast, dynamic coagulation assays (ROTEM and TGA) revealed a hypocoagulable pattern.

Under the dual effect of inflammation and pulmonary fibrosis, CTD-ILD patients possess a greater susceptibility to VTE

As an autoimmune disease, the persistent systemic inflammatory response associated with connective tissue disease (CTD) is involved in the development of venous thromboembolism (VTE). However, clinical data showed that the risk of VTE in patients differed between subtypes of CTD, suggesting that different subtypes may have independent mechanisms to promote the development of VTE, but the specific mechanism lacks sufficient research at present. The development of pulmonary fibrosis also contributes to the development of VTE, and therefore, patients with CTD-associated interstitial lung disease (CTD-ILD) may be at higher risk of VTE than patients with CTD alone or patients with ILD alone. In addition, the activation of the coagulation cascade response will drive further progression of the patient's pre-existing pulmonary fibrosis, which will continue to increase the patient's risk of VTE and adversely affect prognosis. Currently, the treatment for CTD-ILD is mainly immunosuppressive and antirheumatic therapy, such as the use of glucocorticoids and janus kinase-inhibitors (JAKis), but, paradoxically, these drugs are also involved in the formation of patients' coagulation tendency, making the clinical treatment of CTD-ILD patients with a higher risk of developing VTE challenging. In this article, we review the potential risk factors and related mechanisms for the development of VTE in CTD-ILD patients to provide a reference for clinical treatment and prevention.