Hyperhemolysis syndrome in a patient with sickle cell anemia: case report

Sickle cell anemia (SCA) is a genetic disorder characterized by homozygous hemoglobin S (Hb S), chronic hemolytic anemia and painful episodes.1 Patients with SCA usually require red blood cell (RBC) transfusions to manage complications and to reduce morbidity during surgical procedures.1 One possible complication of multiple transfusions is alloimmunization, which occurs due to the recognition of foreign surface antigens on transfused RBC by antibodies produced by the recipient (alloantibodies).2,3 This phenomenon can lead to a delayed hemolytic transfusion reaction/hyperhemolysis syndrome (DHTR/HS).1 However, patients who present this syndrome generally do not show any new alloantibodies, and a direct antiglobulin test (DAT) is usually negative.4,5 As no new antibodies are detected and the symptoms can be confused with other SCA complications, this syndrome represents an important diagnostic challenge. The recognition of this syndrome is important for the management of the symptoms and to prevent future onsets. As it is triggered by blood