Lupus anticoagulant positivity is not associated with venous thromboembolism or in-hospital mortality in COVID-19

Background : Antiphospholipid antibodies (APA) clinical relevance in COVID-19 is controversial. Aims : We aimed to investigate the prevalence and prognostic value of conventional and non-conventional APA in COVID-19 patients. Methods : This study was a multi-centric, prospective observational French cohort of patients hospitalized for COVID-19 suspicion. Results : 249 patients were hospitalized for suspected COVID-19, including 154 (61.8%) with confirmed COVID-19 and 95 (38.2%) not confirmed. We found a significant increase in lupus anticoagulant (LA) positivity among COVID-19 positive patients (60.9% versus 23.7% in non-COVID19 patients, P < 0.001), while prevalence of conventional (LA, IgG, IgM and IgA isotypes) and non-conventional APA (anti-phosphatidylserine/prothrombin IgG and IgM) were low in both groups. COVID-19 patients with LA positivity had higher levels of fibrinogen (6.0 g/L, IQR 5.0-7.0 versus 5.3 IQR 4.3-6.4, P = 0.028) and C-reactive protein (CRP, 115.5 IQR 66.0-204.8 versus 91.8 mg/L, IQR 27.0-155.1, P = 0.019). Univariate analysis did not show any association between LA positivity and higher risk of venous thromboembolism (VTE, OR 1.02, 95% CI 0.44-2.43, P = 0.95) or inhospital mortality (OR 1.80, 95% CI 0.70-5.05, P = 0.24). Unadjusted and adjusted (to CRP, age and sex) Kaplan-Meier survival curves according to LA positivity confirmed the absence of association with VTE or in-hospital mortality (unadjusted: P = 0.64 and P = 0.26, respectively;adjusted: hazard ratio = 1.13 95% CI 0.48-2.60 and 1.80 95% CI 0.67-5.01). Conclusions : COVID-19 patients have an increased prevalence of LA positivity associated with biological inflammation markers. However, positive LA at admission is not associated with VTE risk and/or inhospital mortality.