Lupus anticoagulant is an independent risk factor for non-thrombotic in-hospital mortality in COVID-19 patients

Background: Thromboembolic disease is a frequent cause of death during SARS CoV-2 infection. Lupus anticoagulant (LA) appears frequently during the acute phase of infection. It is not clear whether it is merely an epiphenomenon or whether it is related to the patients' outcome.

Methods: Prospective observational cohort of 211 patients (118 women, mean age 65 years, range: 18 to 99) hospitalized for COVID-19. All patients were tested for LA at admission and retested six months after discharge.

Results: The LA test was positive in 128 patients (60.7%). The survival probability at 31 days was clearly worse in the LA-positive group (60%) than in the LA-negative group (90%) (P = 0.023). This notable difference in survival was confirmed by multivariate analysis (HR 3.9, 95% CI 1.04-14.5, P = 0.04). However, it was not explained by differences in thrombotic events (three in either group, P = 0.6). LA-positive patients had higher ferritin, CRP and IL-6 levels, and lower PAFI ratio and lymphocyte and platelet counts. Six months after discharge, LA was negative in the vast majority of positive cases (94%).

Conclusion: LA is an independent predictor of in-hospital mortality in COVID-19 patients. It is associated with inflammation and disease severity but not with thromboembolic events. This marker usually disappears at six months.