Sickle cell disease is characterized by chronic hemolytic anemia and blood rheological alterations. In addition, blood coagulation abnormalities have been reported in patients with sickle cell disease and hemolysis-derived products could be involved. The investigators hypothesized that patients with sickle cell disease and severe hemolysis (Lactate Dehydrogenase level > 484 IU/L) could have an increased risk of hypercoagulable state and subsequent thromboembolic complications.

Inclusion Criteria:

• Aged 8 years or older
• Under clinical follow-up for a diagnosis of sickle cell disease, specifically genotypes S/S, S/beta0, or S/C
• Patient covered by a social security or equivalent health insurance plan
• Collection of the non-opposition for adults
• Information of the minor and collection of the non-opposition from both parents

Exclusion Criteria:

• Patient who has undergone a transfusion or therapeutic phlebotomy within the 3 months prior to inclusion
• Patient participating in another interventional research protocol that may interfere with the present protocol (at the investigator's discretion)
• Patient under guardianship, curatorship, or legal protection
• Patient subject to a legal protection measure
• Person admitted to a health or social care institution for purposes other than research

Patients with sickle cell disease, followed regularly by the Sickle Cell Center of Lyon Hospitals (Hospices Civils de Lyon).