D-dimer and COVID-19
Thromboembolism of COVID-19 patients is the fatal sequelae of
hyper-coagulation and fibrinolytic abnormalities. Pulmonary embolism and
deep vein thrombosis (DVT) can cause respiratory failure in severely ill
patients with COVID-19. After death pathology shows that small fibrinous
thrombi in small pulmonary arterioles are very common. Activation of the
coagulation cascade is further supported by endothelial tumefaction,
pulmonary megakaryocytes in the capillaries, and endotheliitis. Elevated
D-dimer is an indicator of the activation of the fibrinolysis system and
removal of clots or extravascular collections of fibrin by plasmin
[8].
Increased D-dimer level has not consistently been observed by all
COVID-19 clinical studies, although it is a broadly applied biomarker
for prognosis and outcomes of anti-thrombosis. There is strong positive
association of elevated D-dimer on admission with mortality, indicating
the prognostic value of an elevated D-dimer for the high risk of death.
There is positive correlation between D-dimer and days from onset to
admission, the need for ventilation and the days are taken for PCR test
reversion to negative. Data shows that prompt admission and clearance of
the SARS-CoV-2 virus may alleviate the severity and reduce fatal events
by preventing hyper-fibrinolysis and inflammation.
D-dimer and other clinical variables’ associations indicate either a
relationship that could be cause-effect or indirect. Few
D-dimer-associated variables have been confirmed as prognostic
biomarkers for developing fatal events and in-hospital mortality.
Extremely elevated plasma D-dimer seems to be the consequence of
hyper-fibrinolysis predominately in the pulmonary capillaries and other
organs. And a dynamic increase in the D-dimer level may be associated
with thromboembolism and higher fatality, while we infer that a
continuous decline by daily testing will generally lead to recovery. D
-dimer was positively associated with the severity of lung injury, the
days from the onset to admission, onset to dyspnea, time is taken to be
PCR negative, and overall mortality. Finally, the variables were
significantly associated with D-dimer were respiratory rate, systolic
pressure, dyspnea, serum K+, neutrophils, globulin,
CRP, ferritin, blood glucose, total bilirubin, mortality, ventilation,
sepsis, and acute cardiac injury [9].
The coagulopathy and abnormal results in coagulation tests have become
common features reported in patients with COVID-19 from the very early
days of the emergence of the new coronavirus strain. COVID-19-dependent
coagulopathy gained attention when PT, aPTT, fibrinogen, and D-dimer
tests were recommended by researchers to evaluate the proper homeostasis
of the system associated with the prognosis of patients. The
prophylactic use of anticoagulants was proven to be effective in
lowering the mortality rate and highlighted the role of the coagulation
system in COVID-19. The link between thrombosis and COVID-19 as an
inflammatory disease has been investigated [10].