Hemolytic transfusion reaction attributable to anti-Di^a

In situations when a patient’s antibody detection test is negative, many institutions have moved from an indirect antiglobulin test (IAT) crossmatch to an electronic crossmatch system. Here we report a case of an acute hemolytic transfusion reaction attributable to anti-Di^a in a patient with a negative antibody detection test. A 22-year-old female patient with a diagnosis of β thalassemia and sickle cell anemia commenced a routine exchange transfusion of 5 units of red blood cells (RBCs) in the apheresis unit as part of her regular treatment. When the patient started receiving the implicated unit, she reported back pain, chest pain, and a feeling of anxiety, suggestive of an acute transfusion reaction. The transfusion was ceased and an investigation of an adverse event was commenced. This case illustrates that the presence of antibodies to low-prevalence antigens remains a significant issue for transfusion-dependent individuals. To prevent other transfusion reactions by anti-Di^a, the addition of Di(a+) cells to the reagent RBCs used for the antibody detection test along with IAT-crossmatching of donor units for all patients with sickle cell disease is recommended. Immunohematology2017;33:6–8.