[Laboratory tests applied to transfusion problems. Identification of dangerous universal donors and their frequency].

We studied 504 subjects, whose blood group wes O; they were periodic or occasional blood donors from Transfusional Center A.V.I.S., Policlinico "Umberto I", Roma. Our research was based on the principle stated by Gandini: he states that the natural isoagglutinin concentration equal or superior to 1:200 and the presence of hemolytic isoantibodies may make universal donors dangerous. Our results indicated that the percentage of this kind of donors is 27.75%. Sice 17.26% of our studied subjects showed hemolytic antibodies, we consider it is sufficient to identify dangerous donors through a dosage of hemolytic isoantibodies.