Although the pathophysiology of severe COVID-19 is poorly understood, coagulopathy near the lungs has been shown to play an important role. Some patients with severe COVID-19 meet International Society on Thrombosis and Haemostasis (ISTH) criteria for disseminated intravascular coagulation (DIC). Coagulopathy, however, in most COVID-19 patients does not conform to classic DIC; COVID-19 rarely leads to bleeding or microangiopathy. Abnormal coagulation laboratory values in severe COVID-19 cases have been noted in several studies, most notably a 3- to 4-fold increase in D-dimer. In addition, fibrinogen levels are typically increased in severe cases of COVID-19 and often correlate with an increase in C-reactive protein (CRP). Compared to classic DIC, the degree of activated partial thromboplastin time (aPTT) elevation and prothrombin time (PT) elevation is not as pronounced, and thrombocytopenia is often mild. It has also been noted that Caucasian and African patients with severe COVID-19 have an increased risk of thrombosis compared to Asian patients. In light of these preliminary findings, the ISTH has issued interim guidance for recognizing and managing coagulopathy in COVID-19. The ISTH recommends testing for D-dimer, PT, and platelet count (in decreasing order of importance) in addition to fibrinogen at hospital admission and to monitor the severity of the illness. More aggressive clinical care and experimental therapies should be considered if these laboratory values worsen. In the absence of any contraindications, low molecular weight heparin should be available to all hospitalized patients with COVID-19. Further studies are needed to determine whether more aggressive anticoagulation and/or anti-inflammatory therapies may be helpful for patients with severe cases of COVID-19.
References:
- Thachil J, Tang N, Gando S, Falanga A, et al. ISTH interim guidance on recognition and management of coagulopathy in COVID-19. J Thromb Haemost. 2020;18: 1023-1026.
- Wang T, Chen R, Liu C, Liang W, et al. Attention should be paid to venous thromboembolism prophylaxis in the management of COVID-19. The Lancet 2020.
- Fogarty H, Townsend L, Chaellaigh C, Bergin C, et al. COVID-19 Coagulopathy in Caucasian patients. British Journal of Haematology 2020.
- Chen N, Xhou M, Dong X, Qu J, et al. Epidemiological and clinical characteristics of 99 case of 2019 novel coronavirus pneumonia in Wuhan, China: a descriptive study. The Lancet 2020; 395: 507-513.
- Wang D, Hu B, Hu C, Zhu F, et al. Clinical characteristics of 138 hospitalized patients with 2019 Novel Coronavirus-infected pneumonia in Wuhan, China. JAMA 2020; 323 (11); 1061-1069.
- American Society of Hematology. COVID-19 Resources. COVID-19 and Coagulopathy: Frequently asked questions.
