Abstract 13625: Association of Antiphospholipid Antibodies With Venous Thromboembolism in COVID-19

Abstract

Introduction: Coagulation abnormalities leading to arterial and venous thrombotic events have been described in patients with COVID-19 and studies have reported an overall pooled incidence of venous thromboembolism (VTE) of 17%, however little is known regarding VTE association with antiphospholipid antibodies in patients with COVID-19. Hypothesis: Antiphospholipid antibodies are associated with VTE events in COVID-19. Methods: This is a retrospective cohort study of COVID-19 patients hospitalized at the University of Virginia Medical Center (UVA). Serum samples were collected and stored in the UVA COVID-19 biorepository. Anti-cardiolipin (aCL) and anti-b2glycoprotein1(ab2GLP1), IgM/IgG titres, were measured from stored samples, using the enzyme-linked immunosorbent assay (ELISA). Specimens were analysed at two distinct time-points/days during the patient’s hospitalization for COVID-19. VTE incidence was collected retrospectively by chart review. The study was approved by the Institutional Review Board at UVA. Two-tailed Mann-Whitney two-sample rank-sum tests were conducted to examine whether there were significant differences in APS antibody levels, and mean change in APS levels between the two time points analysed, and VTE events. Additionally, logistic regression models were constructed to examine whether APS antibody levels and mean change in APS levels had a significant effect on the odds of observing a case of VTE. Results: There were 53 patients included in the study. The mean age of participants was 57.2 years (SD 13.9). VTE did not corelate with the levels of APS at studied time points, or the mean change in APS levels during the disease course. aCL IgM (p = 0.24), aCL IgG (p = 0.92), ab2GLP1 IgM (p = 0.79), and ab2GLP1 IgG (p = 0.79). Changes in the APS antibody levels during the course of the disease were not predictive of the odds of having VTE. Similarly, these changes did not predict the need for ICU care. Conclusions: This study shows that neither the presence of antiphospholipid antibodies nor the change in APS levels during the course of COVID-19 correlated with VTE events.