Irregular Blood Group Antibodies in 200,000 Individuals

A survey is presented of 4168 sera containing irregular blood-group antibodies. The antibodies were found during 309,335 antibody screenings and 135,402 cross matchings of blood samples from about 200,000 individuals. About 50 per cent of the antibodies were anti-D, sometimes together with other antibodies in Rh negatives (D neg), 8 per cent were Rh antibodies in Rh positives (D pos) and many of these antibodies were detectable only by a two-stage enzyme technique and not by AHG-technique. Almost 15 per cent of the antibodies belonged to the Lewis-system. There was a significantly increased number in females of the fertile age, and there was a significant decrease in the number of group O individuals among the Lewis-immunized persons. The low number of group O individuals indicate a hitherto unrecognized relationship between the ABO- and Lewis-systems. Altogether 2.1 per cent of the individuals described possessed one or more irregular antibodies. The importance is discussed of avoiding complications from these antibodies during blood transfusions. It is concluded that a reliable cross-match should include a two-stage enzyme technique as well as the usual saline and AHG tests. It is emphasized that the antibody screening is an efficient prophylactic measure, particularly for smaller hospitals, where complicated cross-matchings are impractical.