Background: Sickle cell disease (SCD) is one of the most commonly inherited diseases worldwide and one of the most frequently occurring genetic disorders in France. Delayed hemolytic transfusion reaction (DHTR) is a classic complication in patients with SCD who undergo blood transfusions, and this condition may lead to hyperhemolysis syndrome (HS). DHTR is described as a transfusion complication and is often associated with anti-RBC antibodies.