Delayed hemolytic transfusion reaction caused by anti-LebH antibody

A major delayed hemolytic transfusion reaction produced by an antibody to Lewisb is reported. Delayed hemolysis following transfusion with Leb-positive red cells was not reported to the blood bank. Severe hemolysis recurred following a second transfusion with Leb-positive cells, but was avoided thereafter with Leb-negative red cells. This is the first reported case of a serious delayed hemolytic transfusion reaction caused by anti-Leb.