TNF-α and IL-8 Are Helpful in the Prediction of Late Post-COVID-19 Venous Thromboembolic Disease—Single-Center Prospective Study

Post-COVID-19 syndrome is associated with persistent inflammation and an elevated risk of late venous thromboembolism (VTE). The role of proinflammatory cytokines has been well documented in the acute phase of the disease, but their potential role in late post-COVID-19 VTE remains unknown. What is the prevalence of VTE among symptomatic post-COVID-19 patients, and which laboratory parameters could enhance the diagnostic accuracy for VTE in these patients? Consecutive patients with objectively confirmed previous SARS-CoV-2 infection, admitted to a single department of lung diseases in a tertiary hospital due to sustained symptoms of dyspnea and/or exercise intolerance, were included. Clinical assessment and laboratory testing, including cytokine profiling (Il-1β, IL-6, IL-8, IL-10, TNF-α), PAI-1, and ferritin, were performed. VTE events (pulmonary embolism and/or deep vein thrombosis) were confirmed by standard imaging. Clinical and laboratory parameters were compared between participants with and without VTE. 108 patients: 69 (63.9%) males and 39 (36.1%) females, entered the study. VTE episodes were diagnosed in 39.8% (16.7% in the course of COVID-19 and 23.1% after the acute phase of the disease). Patients who entered the study ≤6 months and >6 months from acute COVID-19 infection were compared. Median D-dimer concentration was higher in patients with VTE that occurred within 6 months from the COVID-19 diagnosis compared to the non-VTE group (607 ng/mL vs. 428 ng/mL, borderline significance, p = 0.0595). Median_IL-8 concentration was significantly higher in those who developed VTE more than 6 months after COVID-19 compared to non-VTE patients: 10.19 pg/mL vs. 6.61 pg/mL, respectively, p = 0.048. The same was noted for TNF-α (39.02 pg/mL vs. 24 pg/mL, respectively, p = 0.011). The best diagnostic utility for VTE prediction was obtained for TNF-α concentration in symptomatic patients diagnosed >6 months from acute COVID-19 infection (ROC AUC 0.73, 95% CI 0.57–0.91). TNF-α was an independent risk factor of VTE episodes in the whole study group. Detection of elevated IL-8 and TNF-α levels later than 6 months from acute COVID-19 disease may help to identify patients at increased risk of late venous thromboembolism; nevertheless, further studies are needed to validate this observation.