Antiphospholipid antibodies and COVID-19 mortality and thrombotic events; A systematic review and meta-analysis

Among various proposed pathologic mechanisms during the coronavirus disease 2019 (COVID-19) pandemic, overproduction of autoantibodies is not widely studied. Antiphospholipid antibodies (aPLs) are target proteins that have affinity toward charged phospholipids. APLs are thought to have pro-thrombotic potentials that increase during thromboembolism. The present systematic review and meta-analysis aimed to evaluate the relationship between serum aPLs level and COVID-19 mortality, severity, and thrombotic events. This systematic review and meta-analysis was conducted on all open access published articles in Medline, Scopus and Google Scholar. Studies evaluating individuals over the age of 18 years who were diagnosed with COVID-19 and had positive aPLs; and provided data on mortality or thrombotic events were included.  Of the initially identified 512 articles, 22 studies (overall 1462 patients) were finally included in the analysis. The prevalence of positive aPLs was 48.1%. Among the 372 patients with positive aPLs, 156 patients (41.9%) had severe COVID-19 that indicated a significant relationship between COVID-19 severity and aPLs positivity (p<0.05). The prevalence of thrombotic events in aPLs positive patients was 26.3% that indicated a significant relationship between aPLs positivity and the development of thrombotic events (p=0.03). APLs positivity was related to anytime mortality in COVID-19 patients (p=0.01). The present review demonstrated that aPLs are linked to COVID-19 severity and thrombotic events but not short-term mortality. Further studies with longer follow up periods are warranted.