Drug dependent red cell antibodies and intravascular haemolysis occurring in patients treated with 9...

Eleven patients were treated weekly with a new cytostatic drug, 9-hydroxy-methyl-ellipticinium (9 HME). Eight were treated for longer than 4 weeks and three of these developed a drug dependent antibody reacting with normal red cells. In two of these patients acute intravascular haemolysis occurred, one with oliguric renal failure; in the third patient the drug was stopped as soon as the antibody was detected. In all three patients the antibody developed after 4 weeks of treatment. It was IgM, agglutinated normal red cells and bound complement only in the presence of the drug. No antibodies could be detected in the patient's serum reacting with normal platelets in the presence of the drug. The incidence of haemolysis with this drug is much higher than seen with other drugs causing immune-complex haemolysis. Studies done with closely related substances suggest that the antigenic site of the drug is related to the group attached to carbon atom 9.