Sustained Expression of Plasminogen Activator Inhibitor-1 in Patients Recovered from COVID-19 Disease.

OBJECTIVES: The overexpression of plasminogen activator inhibitor-1 (PAI-1) was frequently observed during coronavirus disease 2019 (COVID-19), and it was found to be closely associated with disease severity. We have analyzed the PAI-1 status in fully recovered post-COVID patients. SUBJECTS AND METHODS: In a case-control and cross-sectional study, we compared 377 patients, 30-210 days after PCR-verified COVID-19 and 884 COVID-naive controls. RESULTS: Post-COVID patients ("cases") showed significantly higher plasma PAI-1 concentrations than COVID-naive controls. This difference remained significant even after complex adjustment by multiple regression. On the other hand, since the strongest covariate of increased PAI-1 was antihypertensive treatment, the difference between cases and controls in those who were on antihypertensives completely disappeared. In the subgroup of post-COVID patients only, we also found that highly symptomatic patients or those who required hospitalization in the acute phase showed significantly higher PAI-1 than patients with only mild symptoms of the disease. Similarly, the presence of β mutation increased the relative risk (≈11 times) of high post-COVID concentrations of PAI-1. Similarly, the presence of β mutation increased the relative risk (≈11 times) of high post-COVID concentrations of PAI-1. CONCLUSIONS: Increased values of PAI-1 can persist for several months after complete recovery from COVID-19 (namely, by β variant of the virus), and their expression also corresponded to clinical course of the disease.