Development of warm auto- and alloantibodies in a three year-old boy with sickle cell hemoglobinopathy following his first transfusion of a single unit of red blood cells.

Alloimmunisation is a very common problem for blood banks; foreign red blood cell (RBC) antigens induce the formation of antibodies in a manner that depends on the immunogenicity of the antigen as well as on genetic and environmental factors. Alloimmunisation is estimated to occur in 0.3% to 38% of the population1, but it can occur in almost 50% of multiply transfused patients2,such as those with sickling haemoglobinopathies and thalassaemia. Autoantibodies, which are antibodies directed against a patient’s self-antigens, are less widely recognised as a complication of multiple transfusions3 but may be clinically significant. Autoantibodies may make it difficult to identify co-existing alloantibodies, delaying the identification of appropriately matched blood products, since most warm autoantibodies react with most donor RBC. In addition, autoantibodies can be associated with clinically significant warm autoimmune haemolytic anaemia3. In this report, we describe the case of a child with sickle cell anaemia who developed both auto- and alloantibodies following a transfusion of a single unit of packed RBC. (...)