[Problematic blood transfusion (author's transl)].

Two patients were admitted with signs of haemolysis due to severe transfusion reactions. Serological investigations showed the presence of the antibodies anti-IKb and anti-Fya. After a short period of haemodialysis the patient with Kidd antibodies died. A further patient with triple antibodies (anti-c, -K, -Lub) was so pre-immunised that with an antigen frequency of over 99.9% no compatible blood could be found in Europe. By means of information from the European Central Index in Amsterdam compatible blood for the operation could be obtained from Australia. In the fourth case the antibody anti-Cob was found which had not previously been described in Germany and with which the phenotype could be determined in 1405 unselected persons in the German population. The frequency of Cob is 7.2%.