Frequency of lupus anticoagulant in Covid-19 patients.

We have recently published in the Journal of Thrombosis and Haemostasis the presence of lupus anticoagulant (LAC) at high frequency in Covid-19 patients (Harzallah et al.1 ). Bowles et al.2 and Helms et al.3 have confirmed these results in new publications. Tang4 has reported discordant data. He has found that very few tested covid-19 patients had positive LAC in a small series (n=12). Bowles et al. have found that LAC were positive in 91% of patients (n=34) with high activated partial thromboplastin time (aPTT).