Blood group alloantibodies: an assessment of some laboratory practices.

Over a 20-year period, the number of blood donors and transfusion recipients previously immunized by blood group antigens was determined in a large blood center. During that period, the proportion of patients found to have anti-D declined, while those with other antibodies in the Rh system, as well as in the Kell, Duffy, and Kidd systems, increased sharply. As expected, the rate of sensitization was much lower among blood donors than among recipients. In both groups, sensitized females greatly outnumbered sensitized males. Some of the findings summarized here raise questions about current practices in transfusion laboratories and emphasize the responsibilities of blood bank professionals to donors as well as to patients.