A delayed hemolytic transfusion reaction, appearing seven days after transfusions, characterized by jaundice, hemolysis and hemoglobinuria accompanied by the appearance of multiple antibodies in the patient's serum (anti‐hr″ (c) anti‐rh″ (E) and anti‐Jkb) is explained as an anamnestic phenomenon. The original sensitizing antigens and those which precipitated the recall mechanism may be traced to her 20‐year‐old son and to the single‐unit transfusion which she received five years previous to the last admission, and to the transfusions given with the operation from which she recovered.
The important fact is that these latent antibodies failed to be detected by standard crossmatching tests (saline, high protein and Coombs) and by a pool of cells containing most of the antigens. The triple enzyme method was the only test which detected the anti‐rh″ (E) antibody.
The direct Coombs test became positive at the height of the reaction and persisted for 48 hours. Blood tests after 31/2 and 41/2 months revealed that both the anti‐Jkb and anti‐rh″ (E) antibodies had vanished and only anti‐hr‘ (c) of low titer was still present.