Blood groups changes in preleukemic states.

Modifications of blood groups in the course of malignant hemopathies are related to the disease itself and appear to be essentially clonal. They refer not only to the glycolipidic ABH and associated antigens, but also to other blood group systems or other genetic markers. These multiple abnormalities are observed in the preleukemic states as well as in the actual leukaemias. Similar but limited to one genetic unit abnormalities have been noticed among apparently normal subjects, especially in the aged. The various modifications observed are indeed related to the genetic function, and the clonal character is in favor of this assumption. The evidence of abnormalities affecting two genetic systems which are linked ABO and AK is a further argument supporting this hypothesis. Furthermore, the distribution of immunoglobulin marker abnormalities corresponds to that of one of the haplotypes of the Gm genotype. Finally, we were able to demonstrate that the glycosyltransferase itself is abnormal too, in the case of ABH antigen abnormalities. In all the cases investigated to date, when apparently new characters seemed to be observed, they are in fact unconverted substrates, which are to be compared to the carcinoembryonic antigens.