Mustafa Oran1, Seval Akpınar2, Mustafa Doğan3, Burcu Altındağ Avcı2, Aliye Çelikkol4, Burhan Turgut2


1Tekirdağ Namık Kemal University Hospital, Department of Internal Medicine, Turkey - 2Namik Kemal University Medical School, Department of Internal Medicine, Division of Hematology, Turkey - 3Namik Kemal University Medical School, Department of Infectious Disease, Turkey - 4Namik Kemal University Medical School, Department of Medical Biochemistry, Turkey


Introduction: Obesity, by causing hypofibrinolysis and thrombotic complications, ought to be a risk factor in terms of disease severity and mortality in COVID-19 infection.We aim to investigate the effects of obesity on fibrinolytic system in coronavirus patients while studying the changes of major fibrinolytic inhibitors plasminogen activator inhibitor (PAI-1) and thrombin activatable fibrinolysis inhibitor (TAFI).

Material and methods: Sixty-six patients and 21 healthy donors were investigated and observed until either their recovery or death. Body mass index (BMI) was calculated for each person and peripheral blood used for PAI-1 and TAFI measurements. PAI-1 antigen and TAFI activated/inactivated (TAFIa/i) were measured using ELISA kits.

Results: PAI-1 antigen and TAFIa/i plasma levels are higher in patients than in control group (P<00001 for both).Patients needing ICU had higher TAFIa/i values than non-ICU patients. The 15 patients who died had higher TAFIa/i levels than those staying alive.Obese patients (BMI ≥ 30) had higher PAI-1 levels than non-obese patients. TAFIa/i is associated with D-dimer, C-reactive protein (CRP), ferritin, creatinine and neutrophile count, whereas PAI-1 is associated only with the serum creatinine level.

Conclusion: Our study shows that the levels of the major fibrinolytic inhibitors PAI 1 and TAFI increase in patients with COVID-19 infection, and proves for the first time that PAI 1 levels increase more in obese patients than in non-obese ones. It is also revealed that the plasma TAFI level is associated with the severity of COVID-19 infection, which suggests that the inhibitory treatments against TAFI should be effective in preventing thrombotic complications in the course of COVID-19 infection.


COVID-19, Plasminogen activator inhibitor-1, Thrombin activatable fibrinolysis inhibitor, obesity.