Inclusion criteria:  Adult patient (≥18 years old) Patient taken care of in the SMO pole or the NHC surgical resuscitation service or hospitalized or consultant to the HUS between 01/03/2020 and 31/05/2020 Patient infected with Covid-19, with a documented infection, having presented a documented thrombosis (arterial or venous), with an LA or aPL in the thrombosis assessment or Patient infected with Covid-19, with a documented infection, without documented thrombosis (arterial or venous), with in the standard work-up an increase in TCA revealing the presence of LA Subject having given his agreement for the reuse of his data for the purposes of this research  Exclusion criteria:  Subject having expressed opposition to participating in the study Subject under guardianship or guardianship Subject under safeguard of justice