Hyperhemolytic Syndrome Complicating a Delayed Hemolytic Transfusion Reaction due to anti-P1 Alloimmunization, in a Pregnant Woman with HbO-Arab/β-Thalassemia

BACKGROUND Hyperhemolytic Syndrome or Hyperhemolytic Transfusion Reaction (HHTR), a life-threatening subset of Delayed Hemolytic Transfusion Reaction (DHTR) is characterized by destruction of both transfused and autologous erythrocytes evidenced by a fall in post transfusion hemoglobin below the pre-transfusion level. CASE REPORT We describe a case of DHTR due to anti-P1 alloimmunization manifesting with hyperhemolysis in a 30-year-old Greek Pomak woman with thalassemia intermedia (HbO-Arab/β-thalassemia), during the11th week of her first gestation. She was successfully managed with avoidance of further transfusions and administration of IVIG and corticosteroids. CONCLUSION A high index of suspicion for HHTR is of vital importance among clinicians especially since optimal methods for its prevention and treatment remain yet to be defined. Early recognition of HHTR leading to prompt cessation of additional transfusions and initiation of immunosuppressive treatment can be life-saving, especially in clinical settings where limited therapeutic options are available, such as in pregnancy.