Confirmation of the Existence of Human Serum Leukaemia-Associated Antigens (LAA)

We have obtained antisera from rabbits which react with serum from several leukaemia patients after absorption with normal human serum. The specificities of these rabbit antisera have been shown to be closely related to those of the original anti-LAA antisera of Viza et al (1970) and Harris et al (1971). Thus, the existence of leukaemia associated (but probably not leukaemia specific) serum antigen in man has been confirmed. One of the animals was immunized with normal amniotic fluid obtained at 15–16 weeks of gestation. Thus, LAA seems to be a normal constituent of amniotic fluid. This suggests that LAA is another onco-fetal component.