Repeat ABO-incompatible platelet transfusions leading to haemolytic transfusion reaction.

A 65-year-old woman, blood group A RhD positive, who had completed her first course of induction chemotherapy for acute myeloid leukaemia was transfused with apheresis platelets over a number of days. On three occasions she received group O RhD positive units, which had been screened and found not to contain high-titre anti-A,B isoagglutinins. Following the third unit, she developed a haemolytic transfusion reaction and died soon thereafter. This has led to change in policy of the supplying centre in testing for high-titre anti-A,B isoagglutinins. Blood group O apheresis platelets and fresh-frozen plasma units are now labelled as high titre with a cut-off of 1/50 as compared to the previous cut-off of 1/100 for anti-A,B isoagglutinins. A universal approach to testing donations for high-titre anti-A,B isoagglutinins, better compliance of guidelines and monitoring of patients is necessary.