A DETAILED SEROLOGICAL STUDY ON PREDICTION AND DIAGNOSIS OF ABO HAEMOLYTIC DISEASE OF NEWBORN (ABO HD)

Summary. An evaluation is given of haemolysin, neutralisation, thermostability, saline titration, anti‐Ap antibody absorption and 2‐mercapto‐ethanol studies on the sera from 178 clinically affected ABO HD cases and 130 control cases. The antiglobulin titre on the 2‐mercapto‐ethanol treated sera which determines the IgG titre was the best procedure used for the demonstration of significant immune anti‐A/B antibodies in the maternal sera. The screen series on 5,704 sera from group 0 mothers for the detection of immune anti‐A/B and the attempted prediction of ABO HD revealed that ABO HD occurs with a frequency of about 0.8%. Exchange transfusion was needed in six cases i.e. about 0.1% of all the infants of group O mothers screened. The minimum criteria for the diagnosis of ABO HD are the serological demonstration of incompatible anti‐A/B antibodies in an eluate prepared from the baby' red cells, accompanied by the clinical observation of jaundice, or more rarely pallor due to anaemia, in the infant during the first few days following birth. In the absence of elution or serum studies on a blood sample from the baby, the presence of an incompatible high titre (>256) IgG antibody in the maternal serum provides good presumptive evidence that the baby may be suffering from ABO HD. © 1969 Blackwell Publishing Ltd