Deep Venous Thrombosis in Patients Recovered from COVID-19: A Long-Term Sequel

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), also known as COVID-19 disease has the ability to generate sequelae that extend for weeks or months, giving rise to long-term COVID-19 disease. This condition reduces patients' quality of life and predisposes them to several alterations, including failures in the blood coagulation system. Our laboratory has previously demonstrated abnormalities in endothelial colony-forming cells (ECFCs) of patients recovered from COVID-19.

To analyze the functional state of ECFCs in patients who experienced venous thromboembolic disease (VTD) or arterial thrombosis (AT) during long COVID-19, or post-COVID condition (PCC).

We compared 35 samples of peripheral blood (PB) mononuclear cells (MNCs) from patients with a thrombotic event (who had a healthy lifestyle before infection and were vaccinated) with 10 healthy volunteers and 10 samples from patients with a history of recurrent unprovoked VTD (rVTD) after a COVID-19 infection. The samples were cryopreserved in our laboratory and matched by age 25-50 years old and sex. The frequency, morphological characteristics, proliferation and angiogenic ability of ECFCs were evaluated in all samples.

There were no significant differences between male and female patients, and the laboratory data did not indicate risk factors for VTD or AT. The frequency of ECFCs was not different between controls and patients, but a reduced proliferative capacity, a high percentage of senescence and non-angiogenic activity were observed in VTD samples.

Our results demonstrate a strong association between VTD events in patients with PCC who had a healthy lifestyle prior to infection and ECFCs dysfunction.