Inherited Thrombophilias Are Associated with an Increased Risk of COVID-19 Associated Venous Thromboembolism: A Prospective Population-Based Cohort Study

Background: COVID-19 is associated with high rates of venous thromboembolism (VTE). The impact of common inherited thrombophilias on the development of COVID-19-associated VTE (COVID-19 VTE) is not well understood. Objective: To determine if the presence of inherited thrombophilias modifies the risk of COVID-19 VTE or COVID-19 mortality. Methods: Prospective population-based cohort study evaluating adult participants of the UK Biobank diagnosed with COVID-19 between November 2019 and May 2021. Individuals were of European descent and aged between 45 and 69 at recruitment to UK Biobank. We evaluated six single nucleotide polymorphisms including rs6025 (Factor V Leiden mutation) and rs1799963 (Prothrombin mutation) in addition to two polygenic risk scores (PRS-VTE and PRS-ABO). A genome-wide association study was performed for associations with COVID-19 VTE. COVID-19 VTE was defined using International Classification of Diseases and Related Health Problems, Tenth Revision (ICD-10) codes for VTE following COVID-19 diagnosis. COVID-19 mortality was defined using ICD-10 codes for COVID-19 on the death certificate. Results: Demographic and clinical characteristics are shown in Table 1. Of the 13 712 COVID-19 positive individuals included in the analysis, the median age was 54 years and 52.5% were female. There were 197 (1.4%) cases of COVID-19 VTE and 890 (6.5%) died due to COVID-19. The rs6025 variant, synonymous with FVL, was associated with a 1.8-fold risk of COVID-19 VTE (95% CI 1.040-2.931) (Table 2). The risk of COVID-VTE was also increased with rs2066865 (OR 1.345; 95% CI 1.074-1.675) and the PRS-VTE (OR 1.262; 95% CI 1.081-1.468) (Table 2). COVID-19 VTE was associated with increased COVID-19 mortality (OR 2.731; 95% CI 1.885-3.901) but this study found no association between the studied inherited thrombophilias and COVID-19 mortality (Table 2). On genome-wide analysis, two novel SNPs, rs4975019 and rs2875853, located on chromosomes 4 and 16 respectively, were associated with an increased occurrence of COVID-19 VTE. Conclusions: These data demonstrate that several inherited thrombophilias increase the risk of COVID-19 VTE and suggest that two novel SNPs are associated with COVID-19 VTE. These results suggest that certain inherited thrombophilias may assist in characterising a subgroup of COVID-19 patients at higher risk of thrombotic events who require individualised antithrombotic therapy. Future prospective studies are required to evaluate inherited thrombophilias in this patient cohort. [Figure: see text] DISCLOSURES: No relevant conflicts of interest to declare.