Introduction: Severe COVID-19 illness can lead to thrombotic complications, organ failure, and death. Antithrombin (AT) regulates thromboinflammation and is a key component of chemical thromboprophylaxis. Our goal was to examine the link between AT activity and responsiveness to thromboprophylaxis, markers of hypercoagulability, and inflammation among severe COVID-19 patients. Methods: This was a single-center, prospective observational study enrolling SARS-CoV-2-positive patients admitted to the intensive care unit on prophylactic enoxaparin. Blood was collected daily for 7 days to assess AT activity and anti-factor Xa levels. Patient demographics, outcomes, and hospital laboratory results were collected. Continuous variables were compared using Mann-Whitney tests, and categorical variables were compared using χ2 tests. Multivariable logistic regression was used to determine the association between AT activity and mortality. Results: In 36 patients, 3 thromboembolic events occurred, and 18 (50%) patients died. Patients who died had higher fibrinogen, D-dimer, and C-reactive protein (CRP) levels and lower AT activity. Reduced AT activity was independently associated with mortality and correlated with both markers of hypercoagulability (D-dimer) and inflammation (CRP). Conclusion: Low AT activity is associated with mortality and persistent hypercoagulable and proinflammatory states in severe COVID-19 patients. The anti-thromboinflammatory properties of AT make it an appealing therapeutic target for future studies.

1.
Centers for Disease Control and Prevention. Daily updates of totals by week and state: provisional death counts for coronavirus disease 2019 (COVID-19). Reviewed September 28 https://www.cdc.gov/nchs/nvss/vsrr/covid19/index.htm (Accessed 28 September 2022).
2.
Spiezia L, Boscolo A, Poletto F, Cerruti L, Tiberio I, Campello E, et al. COVID-19-Related severe hypercoagulability in patients admitted to intensive care unit for acute respiratory failure. Thromb Haemost. 2020 Jun;120(6):998–1000.
3.
Centers for Disease Control and Prevention. COVID data tracker weekly Review. Updated 23 september 2022 https://www.cdc.gov/coronavirus/2019-ncov/covid-data/covidview/index.html (Accessed 28 September 2022).
4.
Han H, Yang L, Liu R, Liu F, Wu KL, Li J, et al. Prominent changes in blood coagulation of patients with SARS-CoV-2 infection. Clin Chem Lab Med. 2020 Jun 25;58(7):1116–20.
5.
Wiedermann CJ, Romisch J. The anti-inflammatory actions of antithrombin--a review. Acta Med Austriaca. 2002;29(3):89–92.
6.
Levy JH, Sniecinski RM, Welsby IJ, Levi M. Antithrombin: anti-inflammatory properties and clinical applications. Thromb Haemost. 2016 Apr;115(4):712–28.
7.
Lopez E, Peng Z, Kozar RA, Cao Y, Ko TC, Wade CE, et al. Antithrombin III contributes to the protective effects of fresh frozen plasma following hemorrhagic shock by preventing syndecan-1 shedding and endothelial barrier disruption. Shock. 2020 Feb;53(2):156–63.
8.
Niederwanger C, Hell T, Hofer S, Salvador C, Michel M, Schenk B, et al. Antithrombin deficiency is associated with mortality and impaired organ function in septic pediatric patients: a retrospective study. PeerJ. 2018;6:e5538.
9.
Cardenas JC, Wang YW, Karri JV, Vincent S, Cap AP, Cotton BA, et al. Supplementation with antithrombin III ex vivo optimizes enoxaparin responses in critically injured patients. Thromb Res. 2020 Mar;187:131–8.
10.
Rahbar E, Cotton BA, Wade CE, Cardenas JC. Acquired antithrombin deficiency is a risk factor for venous thromboembolism after major trauma. Thromb Res. 2021 Aug;204:9–12.
11.
Vincent LE, Talanker MM, Butler DD, Zhang X, Podbielski JM, Wang YWW, et al. Association of changes in antithrombin activity over time with responsiveness to enoxaparin prophylaxis and risk of trauma-related venous thromboembolism. JAMA Surg. 2022 Aug 1;157(8):713–21.
12.
Anaklı İ, Ergin Ozcan P, Polat O, Orhun G, Alay GH, Tuna V, et al. Prognostic value of antithrombin levels in COVID-19 patients and impact of fresh frozen plasma treatment: a retrospective study. Turk J Haematol. 2021 Feb 25;38(1):15–21.
13.
Thachil J, Tang N, Gando S, Falanga A, Cattaneo M, Levi M, et al. ISTH interim guidance on recognition and management of coagulopathy in COVID-19. J Thromb Haemost. 2020 May;18(5):1023–6.
14.
Wei MY, Ward SM. The anti-factor Xa range for low molecular weight heparin thromboprophylaxis. Hematol Rep. 2015 Nov 23;7(4):5844.
15.
Diggle PJ, Heagerty P, Liang KY, Zeger SL. Analysis of longitudinal data. 2nd ed. Oxford: Oxford University Press; 2002.
16.
Bikdeli B, Madhavan MV, Jimenez D, Chuich T, Dreyfus I, Driggin E, et al. COVID-19 and thrombotic or thromboembolic disease: implications for prevention, antithrombotic therapy, and follow-up. J Am Coll Cardiol. 2020 Jun 16;75(23):2950–73.
17.
Ali MAM, Spinler SA. COVID-19 and thrombosis: from bench to bedside. Trends Cardiovasc Med. 2021 Apr;31(3):143–60.
18.
Page EM, Ariens RAS. Mechanisms of thrombosis and cardiovascular complications in COVID-19. Thromb Res. 2021 Apr;200:1–8.
19.
Joshi D, Manohar S, Goel G, Saigal S, Pakhare AP, Goyal A. Adequate antithrombin III level predicts survival in severe COVID-19 pneumonia. Cureus. 2021 Oct;13(10):e18538.
20.
Ranucci M, Ballotta A, Di Dedda U, Baryshnikova E, Dei Poli M, Resta M, et al. The procoagulant pattern of patients with COVID-19 acute respiratory distress syndrome. J Thromb Haemost. 2020 Jul;18(7):1747–51.
21.
Rezaie AR, Giri H. Anticoagulant and signaling functions of antithrombin. J Thromb Haemost. 2020 Dec;18(12):3142–53.
22.
Ishikawa M, Yamashita H, Oka N, Ueda T, Kohama K, Nakao A, et al. Antithrombin III improved neutrophil extracellular traps in lung after the onset of endotoxemia. J Surg Res. 2017 Feb;208:140–50.
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