Introduction
Hyperhemolysis syndrome (HS), a potentially life-threatening condition, was first described in sickle cell disease but was subsequently seen in other hematological conditions such as thalassemia, myelofibrosis and lymphoma1. This syndrome is characterised by the occurrence of severe anemia with posttransfusion hemoglobin levels being lower than pretransfusion levels2. Intravascular destruction of both host and transfused red blood cells occurs as evident by the presence of positive hemolytic markers such as indirect hyperbilirubinemia, elevated lactate dehydrogenase (LDH), hemoglobinuria, severe reticulocytopenia and decreased serum haptoglobin. HS is categorised into acute and delayed forms. The acute form occurs within the first 7 days of red cell transfusion meanwhile the delayed form occurs more than 7 days post red cell transfusion3. HS rarely recurs. Here, we describe the possible mechanisms involved in a transfusion dependent beta thalassemia major patient presenting with acute hyperhemolysis syndrome after red cell transfusion.