Abstract
The timely and accurate diagnosis of infection with severe acute respiratory syndrome (SARS) coronavirus 2 (SARS-CoV-2), the cause of coronavirus disease 2019 (COVID-19), remains the cornerstone of efforts to provide appropriated treatment for patients, to limit further spread of the virus and ultimately to eliminate the virus from the human society. We focus this article on (a) developments for improvement of diagnosis of specific SARS-CoV-2 virus, (b) laboratory changes in the immunologic and coagulation system, (c) therapeutic options for anticoagulant treatment of seriously affected patients and (d) on the perspectives through improvement of diagnostic and therapeutic medical procedures.
Introduction
An outbreak of coronavirus disease in late December 2019 (coronavirus disease 2019 [COVID-19]) created a pandemic of severe interstitial pneumonia, which developed within a short time frame of 3 months and involved 187 countries worldwide. COVID-19 pneumonia develops from the severe acute respiratory syndrome (SARS) coronavirus 2 (SARS-CoV-2). Previous strains of this betacoronavirus have been identified in 2003 and 2012 as causing SARS and also the Middle East respiratory syndrome (MERS). More recently, it has been shown that the SARS-CoV-2 virus migrates from nasopharygeal mucosa cells into the alveolar endothelium of the lungs being taken up via angiotensin-converting-enzyme 2 (ACE-2) receptors to be released into the blood stream. Organs with ACE-2 receptors take up the virus and cause local infections in the endothelium of the vascular system [1], [2], myocardium [3], kidney [4] and brain by passing the blood-brain barrier [5], which ultimately cause multiple fatal organ failure [6]. Autopsy of deceased patients indicates these developments of septicaemia and is likely to increase the knowledge of suspected COVID-19-related deaths [7].
Like other severe infections, COVID-19 pneumonia may induce sepsis-induced coagulopathy (SIC) and (if not controlled despite adequate medical therapy) progress to disseminated intravascular coagulation (DIC) [8]. DIC is one of the severe complications identified in patients with pneumonia, septicaemia, malignancy and other severe diseases [9]. The clinical diagnosis of DIC is made on rapid progression of serious deterioration of organ functions resulting in a boost of intravascular thrombin generation and microthrombi with secondary parenchymal bleeding through endothelial leakage [10]. Venous thromboembolism (VTE) may develop in COVID-19 patients via immunologic and toxic activation of intravascular and platelet-released thrombin [7]. The occurrence of fatal pulmonary embolism (PE) may be more frequent than that described so far and is the subject of ongoing examinations in pathology [7].
Onset of disease
The clinical manifestations of COVID-19 infection include fever, myalgia, cough and dyspnoea, and less frequently headache, diarrhoea, nausea, vomiting [11] and dysgeusia as reported in Zika virus infection [12]. Viruses spread through the bloodstream and mainly lodge in the lungs, gastrointestinal tract and heart, presumably concentrated in the tissues expressing ACE-2, a receptor of SARS-CoV-2. The median time from onset of symptoms to first hospital admission was calculated at 7.0 days (4.0–8.0), for shortness of breath at 8.0 days (5.0–13.0), for interstitial pneumonia at 9.0 days (8.0–14.0) and transfer to an intensive care unit (ICU) with mechanical ventilation at 10.5 days (7.0–14.0) mainly due to acute respiratory distress syndrome (ARDS). Forty-one percent of patients had comorbid chronic diseases (cardiovascular, respiratory, cancer, liver and kidney) [13]. The median time from illness onset to discharge was 22.0 days (IQR 18.0–25.0) with no difference between survivors and non-survivors [14].
Viral load and dynamics
Viral load measurements from tissue samples are indicative of active virus replication and are routinely used to monitor severe viral respiratory tract infections, including clinical progression, response to treatment, cure and relapse. Duration of viral load dynamics of posterior oropharyngeal saliva was longer in patients with severe disease (median 21 days, range 14–30 days) compared to patients with mild disease (14 days, 10–21 days) [15]. The median RNA viral load presentation of patients with clinical symptoms was 5.2 log10 copies per mL (range 4.1–7.0, limit of detection: 1 log10 copies per mL). Older age was correlated with higher viral load but not for survivors vs. non-survivors of COVID-19 [16]. Children are also carriers of the SARS-CoV-2 virus [17], but age between 1 and >45 years was not related to viral load [18].
Diagnosis of SARS-CoV-2 infection
The determination of SARS-CoV-2 by a PCR mRNA is the standard of care for objective documentation of the disease. The positive results of PCR mRNA testing decreased over time period from 67% within 7 days after onset of symptoms to 46% during day 15–39. Limitations of the performance of the PCR testing are manifold. Preanalytical errors [19], differences in primers of mRNA and isolated strains of SARS-CoV-2 and methods used for the genetic testing pose difficulties of comparability of tests [20], [21], [22].
Determination of antibodies IgG and IgM in addition to the PCR mRNA of COVD-CoV-19 was reported to improve the sensitivity and specificity of detection over 28 days after onset of symptoms. The median seroconversion time of IgM and then IgG antibodies against SARS-CoV-2 was 12–14 days, respectively. The generation of antibodies was below 40% within the first week and increased to 94% (IgM) and 80% (IgG) over 15 days [23]. Another study reported seroconversion for SARS-CoV-2 IgG and IgM antibodies in 100% of 285 patients with COVID-19 within 19 days after onset of clinical symptoms. IgG and IgM titres became positive simultaneously or sequentially and reached a plateau within 6 days after seroconversion. The authors concluded that serological testing may be helpful for the diagnosis of suspected patients with negative RT-PCR results and for the identification of asymptomatic infections [24].
Point-of-care methods are in development using the lateral flow immunoassay technique that detects IgM and IgG antibodies simultaneously using blood from a finger-prick and presenting results within 15 min. The sensitivity and specificity were 89% and 91%, respectively [25]. However, results of other rapid IgG and IgM tests could not reproduce these findings, and the test was not recommended for clinical use yet [26]. In addition, testing for antibodies only identifies a prior infection, and is inappropriate for early detection [27].
General laboratory findings
Laboratory parameters have been reported as elevated in severely diseased patients at hospital admission and/or increase with deterioration of the disease: alanine aminotransferase, lactate dehydrogenase, high-sensitive C-reactive protein, and levels of levels of IL-2R, IL-6, IL-10 and TNF-α. T lymphocytes, CD4+T and CD8+T cells are decreased and expressions of IFN-γ tended to be lower in non-survivors compared to survivors of the disease [28]. High plasma levels of proinflammatory cytokines (IL-2, IL-7, granulocyte colony-stimulating factor, IP10, MCP1, MIP1A, TNF-α and procalcitonin) have been observed in COVID-19 patients admitted to ICUs, suggesting that a cytokine storm effect may be developing in individuals with severe disease [11]. Elevation of neutrophils, SAA, PCT, CRP, cTnI, D-dimer, LDH and lactate levels, and the decline of lymphocyte counts, can be used as indicators of disease progression [29] (Table 1).
Summary of potentially useful laboratory tests in COVID-19.a
| Initial test set (expected outcome) | – C-reactive protein (CRP; elevated) – Lactate dehydrogenase (LDH; elevated) – Aspartate aminotransferase (AST) and alanine aminotransferase (ALT) (elevated) – D-dimer (elevated) – Fibrinogen (elevated) – PT (slight elevation) – APTT (shortened in acute phase, potentially elevated later) – Albumin (decreased) – Full/complete blood count (platelets and lymphocytes decreased) |
| Tests potentially useful for monitoring patient status | – CRP (monitoring of infection/inflammatory response) – LDH (identification of lung injury and/or multiple organ failure) – ALT/AST/Bilirubin (identification of liver injury) – Albumin (identification of liver failure) – Cardiac troponins (identification of cardiac injury) – Creatinine and blood urea nitrogen (identification of kidney injury and/or failure) – Procalcitonin (identification of bacterial co-infections) – Full/complete blood count (platelets, lymphocytes, neutrophils) – D-dimer, fibrinogen, PT(/APTT) (identification of ongoing [consumption or thrombotic] coagulopathy including DIC) – Electrolytes and glucose (identification of metabolic derangement) – Lactate dehydrogenase (identification of lung injury and/or multiple organ failure) – Creatine kinase (identification of muscle injury) – Lipase (identification of pancreatic injury) – Brain natriuretic peptideb (identification of cardiac failure) – Ferritin (monitoring of infection/inflammatory response) – Presepsinc (monitoring of severity of viral infection) |
a‘Gating rule’: unless clinically justified, testing should not generally be reordered within 24 h of an existing test. bFor selected patients with signs of multiple organ failure or systemic inflammatory response syndrome. Discuss with expert (laboratory) clinician/senior or clinical scientist. cFor patients under intensive care. Modified from Favaloro and Lippi [30].
Diagnosis of disseminated intravascular coagulation
DIC is one of the severe complications identified in patients with pneumonia and other infections [9]. Not surprisingly, the occurrence of DIC has also been described in COVID-19-driven pneumonia. However, diagnosis of DIC is suspected by deterioration of laboratory parameters documented by repeated determinations.
The most frequently determined parameters in COVID-19 patients have been the following: prothrombin time (PT) and activated partial thromboplastin time (APTT) both increase (suggestive of coagulation activation) and decrease (consistent with consumptive coagulopathy), and fibrinogen increases (suggestive of acute-phase changes) and decreases (consumptive coagulopathy). Later stages of the disease are also characterised by increase in thrombin-antithrombin complex, fibrin-degradation products and D-dimers, with the degree of changes related with a risk of fatal outcome [31]. Platelet counts increase in the acute phase of COVID-19 disease [32] but may decrease in late stages of DIC (Table 1). About 71% of non-survivors and 0.6% of survivors showed evidence of overt DIC identified with a median time of 4 days after onset of interstitial pneumonia [33].
Of great interest is the determination of D-dimer levels. A pooled analysis including four studies showed that D-dimer values are three-fold higher in patients with severe COVID-19 than in those with milder forms. When D-dimer levels increased to levels higher than 3 µg/mL, the mortality rate increased three-fold [34]. D-dimer reached maximum levels at a median time of 4 days after onset of interstitial pneumonia in 71% of non-survivors [35]. A multivariable logistic regression model identified older age, higher SOFA score [36] and D-dimer greater than 1 μg/mL at admission to be associated with increased probability of fatal outcome [35]. Patients with COVID-19 pneumonia and PE documented by computerized tomography (CT) angiography had higher D-dimer levels compared to those without PE (median, 6.11 vs. 1.92 μg/mL). D-dimer had a sensitivity and specificity of 100% and 67%, for the presence of PE on CT angiography at a cut-off of 2.66 μg/mL, respectively [37].
Elevations of D-dimer have also been reported in severe courses of other viral infections, including human immunodeficiency (HIV) [38], Ebola [39], Zika and Chikungunya viruses [40].
Therapeutic options for treatment of DIC in COVID-19 disease
Heparins
The International Society of Thrombosis and Haemostasis reported guidelines for treatment therapeutic doses of unfractionated heparin (UFH) or low-molecular-weight heparin (LMWH) if thrombosis predominates and also in critically ill, non-bleeding patients with DIC, despite lacking direct evidence of the beneficial effects [41], [42]. The number of reports currently increases on the potential benefit of heparins in COVID-19 patients. Tang et al. reported 99 patients with COVID-19 with 94 and 5, respectively, receiving LMWH (40–60 mg enoxaparin/day s.c.) or UFH (10,000–15,000 IU/day continuously i.v.) for 7 days or longer. D-dimer, PT and age were positively, and platelet count was negatively correlated with 28-day mortality. When D-dimer exceeded 3.0 μg/mL (six-fold of upper limit of normal), mortality was 20% lower with treatment using LMWH or UFH [35]. Despite systematic thrombosis prophylaxis with low or medium dose of LMWH, 27% of COVID-19 patients admitted to the ICU developed PE as confirmed by pulmonary angio-CT. The authors conclude to recommend higher doses of LMWH for patients with COVID-19 infections admitted to the ICU [43].
Middeldorp et al. reported on the incidences of objectively documented PE and DVT in hospitalised COVID-19 patients, all of them receiving LMWH. PE occurred in 12% and 1.6% of patients treated in the ICU (n=74) and non-ICU ward (n=124), respectively. DVT was documented in another 27% and 1.6% of patients, respectively. Mortality was 3.3 times higher in patients with PE or DVT. Dose of LMWH was doubled in all patients on ICU after termination of reporting results. Further strategies for detecting, treating and assessing risk of VTE post-discharge in COVID-19 are warranted [44].
Despite ongoing observational and clinical studies, many centres have increased the dose of anticoagulation with LMWH to ‘intermediate intensity’ doses such as 0.5 mg/kg twice a day of enoxaparin. A laboratory- and clinical-based thrombosis and bleeding risk-adapted strategy was reported to the decision-making of LMWH dosage [8]. A consensus document found that 31.6% of participants supported intermediate intensity dose, 5.2% therapeutic dose, while the rest supported using standard VTE prophylaxis dose for hospitalised patients with moderate to severe COVID-19 and lack of DIC [10].
National health care professionals, scientific organisations and expert groups univocally recommended the administration of LMWH in COVID-19 patients to treat DIC and VTE and to reduce mortality [45], [46], [47], [48], [49], [50], [51].
Other anticoagulant strategies
In COVID-19, the immune system is compromised by a reduction in T- and B-cell lymphocytes and an increase in inflammatory cytokines and D-dimer. High doses of intravenous immunoglobulin IgG are one of the therapeutic options in acute thrombocytopenic disorders such as immune thrombocytopenic purpura or heparin-induced thrombocytopenia. A combination of 0.5 g/kg bodyweight IgG in combination with LMWH were given for 5 days effectively in patients with a continuous decrease in B- and T-cell lymphocytes and in D-dimer [52].
Activation of the coagulation system results in local fibrin formation together with a suppression of the fibrinolysis system [53], [54]. Administration of tissue plasminogen activator (tPA) has been reported to be effectively and safely used in three patients with COVID-19 complicated by ARDS [55]. Indeed, SARS-CoV-2 is likely to disrupt several fibrinolysis pathways, and this can be hypothesised to contribute to lung pathology and thus to adverse symptomology of breathing [56]. The bleeding risk of patients needs to be taken into consideration for treatment with tPA.
Thrombomodulin acts a receptor for thrombin activating the protein C and protein S pathway and thereby inhibiting blood coagulation through factors V and VIII. A combined analysis of three trials using intravenous recombinant human thrombomodulin reduced the 28-day mortality of COVID-19 patients with DIC by 20% but did not reach clinical significance [57].
Future perspectives
We continue to learn more about COVID-19 every day. And yet there remain many unknowns at the time of writing. The best therapeutic intervention is still under investigation. Certainly, heparin, either UFH or LMWH, is likely to be a life-saver in sufferers of severe disease. However, optimal doses are unknown, and clinicians must finely balance risk of thrombosis vs. bleeding in these patients. Of interest are the antiviral effects of heparins with low or lacking anticoagulant activity [58], [59]. Urgent studies should also be planned to define whether adjunctive antithrombotic therapies (e.g. other anticoagulants, antithrombin or thrombomodulin) may be helpful in patients with severe COVID-19. In some patients, IgG support may also be useful. The early use of convalescent plasma therapy is also being investigated [60].
The pathophysiology of COVID-19 is complex. Most affected patients suffer only mild disease (Figure 1). In those who suffer severe disease, a multitude of events may be occurring. There appears to be an acute phase characterised by activation of coagulation, followed by or co-incident to consumptive events – thus, some patients may present with shortened APTT and elevated fibrinogen, whereas others will present with elevated APTT and reduced fibrinogen – suggesting different patterns based on what happens to be dominant in any given patient.
Summary of concepts detailed in the current review.
What is happening to platelets is also fascinating in these patients; again, both elevations and reductions in platelet count seem to be present in different patients. There is likely initial platelet activation and subsequent clearance of platelets from circulation. Platelets are also known to bind to various viruses and this is a proposed general cause of platelet depletion in infection [61]. The situation with SARS-CoV-2 and platelets is yet to be resolved, but likely to be similar.
Finally, there can be some recommendations for tests to be performed on severely affected patients that may have some prognostic value. A recent publication has provided such a list [30], whilst recognising that the situation remains dynamic and subject to change.
Signal for the urgent need of diagnostic, therapeutic, medical, social and other aspects is given by the large number of over 450 registered clinical trials worldwide (ClinicalTrials.gov). The ultimate information on the multiple causes of death of COVID-19 patients by SARS-CoV-2 virus will be obtained by autopsy of patients with not clearly defined cause of death [62], [63], [64].
Conclusions
Based on the deterioration of coagulation and also the immunologic system, patients with COVID-19 deteriorate and suffer from severe disease. DIC is one of the main complications that evolves rapidly, and that can be diagnosed within a short time frame of a few days. The multifactorial pathophysiology of DIC results in multiple therapeutic options currently available for treatment. However, pathophysiology of COVID-19 is complex (Figure 1), and not all patients may have the same ‘disease’. Thus, although adequate use of at least one of the likely therapeutic options of UFH or LMWH and sequential determination of D-dimer should be followed, specific treatment for each patient may require specific identification of symptomology causality to enable safe prophylaxis and treatment of all individuals with COVID-19, and along the concept of personalised medicine. Increasing rates of autopsies of patients with not objectively confirmed causes of death will improve the understanding of COVID-19 disease to improve the healthcare system and of the welfare of the population.
Research funding: None declared.
Author contributions: All authors have accepted responsibility for the entire content of this manuscript and approved its submission.
Competing interests: Authors state no conflict of interest.
References
1. Iba T, Levy JH. Derangement of the endothelial glycocalyx in sepsis. J Thromb Haemost 2019;17:283–94.10.1111/jth.14371Search in Google Scholar
2. Varga Z, Flammer AJ, Steiger P, Haberecker M, Andermatt R, Zinkernagel AS, et al. Endothelial cell infection and endotheliitis in COVID-19. Lancet 2020;395:1417–8.10.1016/S0140-6736(20)30937-5Search in Google Scholar
3. Rizzo P, Vieceli Dalla Sega F, Fortini F, Marracino L, Rapezzi C, Ferrari R. COVID-19 in the heart and the lungs: could we “Notch” the inflammatory storm? Basic Res Cardiol 2020;115:31.10.1007/s00395-020-0791-5Search in Google Scholar PubMed PubMed Central
4. Su H, Yang M, Wan C, Yi LX, Tang F, Zhu HY, et al. Renal histopathological analysis of 26 postmortem findings of patients with COVID-19 in China. Kidney Int 2020; pii: S0085-2538(20)30369-0. doi: 10.1016/j.kint.2020.04.003. [Epub ahead of print].10.1016/j.kint.2020.04.003Search in Google Scholar PubMed PubMed Central
5. Ye M, Ren Y, Lv T. Encephalitis as a clinical manifestation of COVID-19. Brain Behav Immun 2020; pii: S0889-1591(20)30465-7. doi: 10.1016/j.bbi.2020.04.017. [Epub ahead of print].10.1016/j.bbi.2020.04.017Search in Google Scholar PubMed PubMed Central
6. Du Y, Tu L, Zhu P, Mu M, Wang R, Yang P, et al. Clinical features of 85 fatal cases of COVID-19 from Wuhan: a retrospective observational study. Am J Respir Crit Care Med 2020; doi: 10.1164/rccm.202003-0543OC. [Epub ahead of print].10.1164/rccm.202003-0543OCSearch in Google Scholar PubMed PubMed Central
7. Barton LM, Duval EJ, Stroberg E, Ghosh S, MukhopadhyayS. COVID-19 Autopsies, Oklahoma, USA. Am J Clin Pathol 2020;153:725–33.10.1093/ajcp/aqaa062Search in Google Scholar PubMed PubMed Central
8. Connors JM, Levy JH. COVID-19 and its implications for thrombosis and anticoagulation. Blood 2020; pii: blood.2020006000. doi: 10.1182/blood.2020006000. [Epub ahead of print].10.1182/blood.2020006000Search in Google Scholar PubMed PubMed Central
9. Voves C, Wuillemin WA, Zeerleder S. International Society on Thrombosis and Haemostasis score for overt disseminated intravascular coagulation predicts organ dysfunction and fatality in sepsis patients. Blood Coagul Fibrinolysis 2006;17:445–551.10.1097/01.mbc.0000240916.63521.2eSearch in Google Scholar PubMed
10. 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; pii: S0735-1097(20)35008-7. doi: 10.1016/j.jacc.2020.04.031. [Epub ahead of print].10.1016/j.jacc.2020.04.031Search in Google Scholar PubMed PubMed Central
11. Huang C, Wang Y, Li X, Ren L, Zhao J, Hu Y, et al. Clinical features of patients infected with 2019 novel coronavirus in Wuhan, China. Lancet 2020;395:497–506.10.1016/S0140-6736(20)30183-5Search in Google Scholar
12. Meltzer E, Leshem E, Lustig Y, Gottesman G, Schwartz E. The clinical spectrum of Zika virus in returning travelers. Am J Med 2016;129:1126–30.10.1016/j.amjmed.2016.04.034Search in Google Scholar
13. Backer JA, Klinkenberg D, Wallinga J. Incubation period of 2019 novel coronavirus (2019-nCoV) infections among travellers from Wuhan, China, 20–28 January 2020. Euro Surveill 2020;25. doi: 10.2807/1560-7917. [Epub ahead of print].10.2807/1560-7917.ES.2020.25.5.2000062Search in Google Scholar
14. Zhou F, Yu T, Du R, Fan G, Liu Y, Liu Z, et al. Clinical course and risk factors for mortality of adult in patients with COVID-19 in Wuhan, China: a retrospective cohort study. Lancet 2020;395:1054–62.10.24966/MSR-5657/100015Search in Google Scholar
15. Zheng S, Fan J, Yu F, Feng B, Lou B, Zou Q, et al. Viral load dynamics and disease severity in patients infected with SARS-CoV-2 in Zhejiang province, China, January-March 2020: retrospective cohort study. Br Med J 2020;369:m1443.10.1136/bmj.m1443Search in Google Scholar
16. To KK, Tsang OT, Leung WS, Tam AR, Wu TC, Lung DC, et al. Temporal profiles of viral load in posterior oropharyngeal saliva samples and serum antibody responses during infection by SARS-CoV-2: an observational cohort study. Lancet Infect Dis 2020;20:565–74.10.1016/S1473-3099(20)30196-1Search in Google Scholar
17. Shen KL, Yang YH, Jiang RM, Wang TY, Zhao DC, Jiang Y, et al. Updated diagnosis, treatment and prevention of COVID-19 in children: experts’ consensus statement [condensed version of the second edition]. World J Pediatr 2020; doi: 10.1007/s12519-020-00362-4. [Epub ahead of print].10.1007/s12519-020-00362-4Search in Google Scholar PubMed PubMed Central
18. https://www.t-online.de/gesundheit/krankheiten-symptome/id_87795442/corona-krise-studie-von-christian-drosten-warnt-vor-oeffnung-der-schulen.html. Assessed: 3 May 2020.Search in Google Scholar
19. Lippi G, Simundic AM, Plebani M. Potential preanalytical and analytical vulnerabilities in the laboratory diagnosis of coronavirus disease 2019 (COVID-19). Clin Chem Lab Med 2020;58:1070–6.10.1515/cclm-2020-0285Search in Google Scholar PubMed
20. Ahmed SF, Quadeer AA, McKay MR. Preliminary identification of potential vaccine targets for the COVID-19 coronavirus [SARS-CoV-2] based on SARS-CoV immunological studies. Viruses 2020;12:E254.10.3390/v12030254Search in Google Scholar PubMed PubMed Central
21. Sah R, Rodriguez-Morales AJ, Jha R, Chu DK, Gu H, Peiris M, et al. Complete genome sequence of a 2019 novel coronavirus (SARS-CoV-2) strain isolated in Nepal. Microbiol Resour Announc 2020;9:e00169-20.10.1128/MRA.00169-20Search in Google Scholar PubMed PubMed Central
22. Park WB, Kwon NJ, Choi SJ, Kang CK, Choe PG, Kim JY, et al. Virus Isolation from the First Patient with SARS-CoV-2 in Korea. J Korean Med Sci 2020;35:e84.10.3346/jkms.2020.35.e84Search in Google Scholar PubMed PubMed Central
23. Zhao J, Yuan Q, Wang H, Liu W, Liao X, Su Y, et al. Antibody responses to SARS-CoV-2 in patients of novel coronavirus disease 2019. Clin Infect Dis 2020; pii: ciaa344. doi: 10.1093/cid/ciaa344. [Epub ahead of print].10.1093/cid/ciaa344Search in Google Scholar PubMed PubMed Central
24. Long QX, Liu BZ, Deng HJ, Wu GC, Deng K, Wu GC, et al. Antibody responses to SARS-CoV-2 in patients with COVID-19. Nat Med 2020; doi: 10.1038/s41591-020-0897-1. [Epub ahead of print].10.1038/s41591-020-0897-1Search in Google Scholar PubMed
25. Li Z, Yi Y, Luo X, Xiong N, Liu Y, Li S, et al. Development and clinical application of a rapid IgM-IgG combined antibody test for SARS-CoV-2 infection diagnosis. J Med Virol 2020; doi: 10.1002/jmv.25727. [Epub ahead of print].10.1002/jmv.25727Search in Google Scholar PubMed PubMed Central
26. Cassaniti I, Novazzi F, Giardina F, Salivaro F, Sachs M, Perlini S, et al. Performance of VivaDiagTM COVID-19 IgM/IgG Rapid Test is inadequate for diagnosis of COVID-19 in acute patients referring to emergency room department. J Med Virol 2020; doi: 10.1002/jmv.25800. [Epub ahead of print].10.1002/jmv.25800Search in Google Scholar PubMed PubMed Central
27. Tang YW, Schmitz JE, Persing DH, Stratton CW. The laboratory diagnosis of COVID-19 infection: current issues and challenges. J Clin Microbiol 2020; pii: JCM.00512-20. doi: 10.1128/JCM.00512-20. [Epub ahead of print].10.1128/JCM.00512-20Search in Google Scholar PubMed PubMed Central
28. Chen G, Wu D, Guo W, Cao Y, Huang D, Wang H, et al. Clinical and immunologic features in severe and moderate Coronavirus Disease 2019. J Clin Invest 2020;130:2620–9.10.1101/2020.02.16.20023903Search in Google Scholar
29. Li X, Wang L, Yan S, Yang F, Xiang L, Zhu J, et al. Clinical characteristics of 25 death cases with COVID-19: a retrospective review of medical records in a single medical center, Wuhan, China. Int J Infect Dis 2020;94:128–32.10.1016/j.ijid.2020.03.053Search in Google Scholar PubMed PubMed Central
30. Favaloro EJ, Lippi G. Commentary: Recommendations for Minimal Laboratory Testing Panels in Patients with COVID-19: Potential for Prognostic Monitoring. Semin Thromb Hemost 2020;46:379–82.10.1055/s-0040-1709498Search in Google Scholar PubMed PubMed Central
31. 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;58:1116–20.10.1515/cclm-2020-0188Search in Google Scholar PubMed
32. Lippi G, Plebani M, Henry BM. Thrombocytopenia is associated with severe coronavirus disease 2019 [COVID-19] infections: a meta-analysis. Clin Chim Acta 2020;506:145–8.10.1016/j.cca.2020.03.022Search in Google Scholar PubMed PubMed Central
33. Tang N, Bai H, Chen X, Gong J, Li D, Sun Z. Anticoagulant treatment is associated with decreased mortality in severe coronavirus disease 2019 patients with coagulopathy. J Thromb Haemost 2020;18:844–7.10.1111/jth.14768Search in Google Scholar PubMed PubMed Central
34. Lippi G, Favaloro EJ. D-dimer is associated with severity of coronavirus disease 2019 [COVID-19]: a pooled analysis. Thromb Haemost 2020;120:876–8.10.1055/s-0040-1709650Search in Google Scholar PubMed PubMed Central
35. Tang N, Bai H, Chen X, Gong J, Li D, Sun Z. Anticoagulant treatment is associated with decreased mortality in severe coronavirus disease 2019 patients with coagulopathy. J Thromb Haemost 2020;18:1094–9.10.1111/jth.14817Search in Google Scholar PubMed
36. Singer M, Deutschman CS, Seymour CW, Shankar-Hari M, Annane D, Bauer M, et al. The Third international consensus definitions for sepsis and septic shock (Sepsis-3). J Am Med Assoc 2016;315:801–10.10.1001/jama.2016.0287Search in Google Scholar PubMed PubMed Central
37. Leonard-Lorant I, Delabranche X, Severac F, Helms J, Pauzet C, Collange O, et al. Acute pulmonary embolism in COVID-19 patients on CT angiography and relationship to D-dimer levels. Radiology 2020;201561. doi: 10.1148/radiol.2020201561. [Epub ahead of print].10.1148/radiol.2020201561Search in Google Scholar PubMed PubMed Central
38. Grund B, Baker JV, Deeks SG, Wolfson J, Wentworth D, Cozzi-Lepri A, et al. Relevance of interleukin-6 and D-dimer for serious non-AIDS morbidity and death among HIV-positive adults on suppressive antiretroviral therapy. PLoS One 2016;11:e0155100.10.1371/journal.pone.0155100Search in Google Scholar PubMed PubMed Central
39. Rollin PE, Bausch DG, Sanchez A. Blood chemistry measurements and D-Dimer levels associated with fatal and nonfatal outcomes in humans infected with Sudan Ebola virus. J Infect Dis 2007;196(Suppl 2):S364–71.10.1086/520613Search in Google Scholar PubMed
40. Ramacciotti E, Agati LB, Aguiar VC, Wolosker N, Guerra JC, de Almeida RP, et al. Zika and Chikungunya Virus and Risk for Venous Thromboembolism. Clin Appl Thromb Hemost 2019;25:1076029618821184. doi: 10.1177/1076029618821184. 10.1177/1076029618821184Search in Google Scholar PubMed PubMed Central
41. Wada H, Thachil J, Di Nisio M, Mathew P, Kurosawa S, Gando S, et al. Guidance for diagnosis and treatment of DIC from harmonization of the recommendations from three guidelines. J Thromb Haemost 2013;11:761–7.10.1111/jth.12155Search in Google Scholar PubMed
42. Lillicrap D. Disseminated intravascular coagulation in patients with 2019-nCoV pneumonia. J Thromb Haemost 2020;18:786–7.10.1111/jth.14781Search in Google Scholar PubMed PubMed Central
43. Klok FA, Kruip MJ, van der Meer NJ, Arbous MS, Gommers DA, Kant KM, et al. Incidence of thrombotic complications in critically ill ICU patients with COVID-19. Thromb Res 2020; pii: S0049-3848(20)30120-1. doi.org/10.1016/j.thromres.2020.04.013. [Epub ahead of print].10.1016/j.thromres.2020.04.013Search in Google Scholar PubMed PubMed Central
44. Middeldorp S, Coppens M, van Haaps TF, Foppen M, Vlaar AP, Muller MC, et al. Incidence of venous thromboembolism in hospitalized patients with COVID-19. Preprints 2020; doi: 10.20944/preprints202004.0345.v1. [Epub ahead of print].10.20944/preprints202004.0345.v1Search in Google Scholar
45. Casini A, Alberio L, Angelillo-Scherrer A, Fontana P, Gerber B, et al. Thromboprophylaxis and laboratory monitoring for in-hospital patients with Covid-19 - a Swiss consensus statement by the Working Party Hemostasis. Swiss Med Wkly 2020;150:w20247. doi: 10.4414/smw.2020.20247. eCollection 2020.10.4414/smw.2020.20247Search in Google Scholar PubMed
46. http://gth-online.org/wp-content/uploads/2020/04/GTH-Empfehlungen-COVID-19.pdf. Assessed: 3 May 2020.Search in Google Scholar
47. https://www.aifa.gov.it/documents/20142/1123276/Eparine_Basso_Peso_Molecolare_11.04.2020.pdf/e30686fb-3f5e-32c9-7c5c-951cc40872f7. Assessed: 3 May 2020.Search in Google Scholar
48. Song JC, Wang G, Zhang W, Zhang Y, Li WQ, Zhou Z, et al. Chinese expert consensus on diagnosis and treatment of coagulation dysfunction in COVID-19. Mil Med Res 2020;7:19.10.1186/s40779-020-00247-7Search in Google Scholar PubMed PubMed Central
49. Vivas D, Roldán V, Esteve-Pastor MA, Roldán I, Tello-Montoliu A, Ruiz-Nodar JM, et al. Recommendations on antithrombotic treatment during the COVID-19 pandemic. Position statement of the Working Group on Cardiovascular Thrombosis of the Spanish Society of Cardiology. Rev Esp Cardiol 2020; doi: 10.1016/j.recesp.2020.04.006. [Epub ahead of print].10.1016/j.rec.2020.04.025Search in Google Scholar PubMed PubMed Central
50. Barrett CD, Moore HB, Yaffe MB, Moore EE. ISTH interim guidance on recognition and management of coagulopathy in COVID-19: a comment. J Thromb Haemost 2020; doi: 10.1111/jth.14860. [Epub ahead of print].10.1111/jth.14860Search in Google Scholar PubMed
51. Cattaneo M, Bertinato EM, Birocchi S, Brizio C, Malavolta D, Manzoni M, et al. Pulmonary Embolism or Pulmonary Thrombosis in COVID-19? Is the recommendation to use high-dose heparin for thromboprophylaxis justified? Thromb Haemost 2020; doi: 10.1055/s-0040-1712097. [Epub ahead of print].10.1055/s-0040-1712097Search in Google Scholar PubMed PubMed Central
52. Lin L, Lu L, Cao W, Li T. Hypothesis for potential pathogenesis of SARS-CoV-2 infection–a review of immune changes in patients with viral pneumonia. Emerg Microbes Infect 2020;9:727–32.10.1080/22221751.2020.1746199Search in Google Scholar PubMed PubMed Central
53. Tian S, Hu W, Niu L, Liu H, Xu H, Xiao SY. Pulmonary pathology of early-phase 2019 novel coronavirus (COVID-19) pneumonia in two patients with lung cancer. J Thorac Oncol 2020;15:700–4.10.1016/j.jtho.2020.02.010Search in Google Scholar PubMed PubMed Central
54. Bastarache JA, Ware LB, Bernard GR. The role of the coagulation cascade in the continuum of sepsis and acute lung injury and acute respiratory distress syndrome. Semin Respir Crit Care Med 2006;27:365–76.10.1055/s-2006-948290Search in Google Scholar PubMed
55. Wang J, Hajizadeh N, Moore EE, McIntyre RC, Moore PK, et al. Tissue plasminogen activator (tPA) treatment for COVID-19 associated acute respiratory distress syndrome (ARDS): a case series. J Thromb Haemost 2020; doi: 10.1111/jth.14828. [Epub ahead of print].10.1111/jth.14828Search in Google Scholar PubMed PubMed Central
56. Kwaan H. COVID 19: the role of fibrinolytic system from transmission to organ injury and sequelae. Semin Thrombos Hemost 2020; accepted for publicationSearch in Google Scholar
57. Valeriani E, Squizzato A, Gallo A, Porreca E, Vincent JL, Iba T, et al. Efficacy and safety of recombinant human soluble thrombomodulin in patients with sepsis-associated coagulopathy: a systematic review and meta-analysis. J Thromb Haemost 2020; doi: 10.1111/jth.14812. [Epub ahead of print].10.1111/jth.14812Search in Google Scholar PubMed
58. Mulloy B, Hogwood J, Gray E, Lever R, Page CP. Pharmacology of heparin and related drugs. Pharmacol Rev 2016;68:76–141.10.1124/pr.115.011247Search in Google Scholar PubMed
59. Mycroft-West CJ, Devlin AJ, Cooper LC, Procter P, Miller GJ, Fernig DG, et al. Inhibition of BACE1, the β-secretase implicated in Alzheimer’s disease, by a chondroitin sulfate extract from Sardina pilchardus. Neural Regen Res 2020;15:1546–53.10.4103/1673-5374.274341Search in Google Scholar PubMed PubMed Central
60. Bloch EM, Shoham S, Casadevall A, Sachais BS, Shaz B, Winters JL, et al. Deployment of convalescent plasma for the prevention and treatment of COVID-19. J Clin Invest 2020; pii: 138745. doi: 10.1172/JCI138745. [Epub ahead of print].10.1172/JCI138745Search in Google Scholar PubMed PubMed Central
61. Page MJ, Pretorius E. A champion of host defence: a generic large-scale cause for platelet dysfunction and depletion in infection. Semin Thromb Hemost 2020;46:302–19.10.1055/s-0040-1708827Search in Google Scholar PubMed PubMed Central
62. Society of Pathological Doctors, Chinese Medical Doctors Association; Chinese Society of Pathology, Chinese Medical Association. Provisional guidelines on autopsy practice for deaths associated with COVID-19. Zhonghua Bing Li Xue Za Zhi 2020;49:E006. Chinese. Search in Google Scholar
63. Fineschi V, Aprile A, Aquila I, Arcangeli M, Asmundo A, Bacci M, et al. Management of the corpse with suspect, probable or confirmed COVID-19 respiratory infection – Italian interim recommendations for personnel potentially exposed to material from corpses, including body fluids, in morgue structures and during autopsy practice. Pathologica 2020; doi: 10.32074/1591-951X-13-20. [Epub ahead of print].Search in Google Scholar
64. Wichmann D, Sperhake JP, Lütgehetmann M, Steurer S, Edler C, Heinemann A, et al. Autopsy findings and venous thromboembolism in patients with COVID-19: a prospective cohort study. Ann Intern Med 2020; doi:10.7326/M20-2003. [Epub ahead of print].10.7326/M20-2003Search in Google Scholar PubMed PubMed Central
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