[Immunohematological study of 7 cases of acquired B transformation using anti-B and selected acquired anti-B]

Seven acquired B samples were studied with selected anti-B sera. Eight sera came from group A subjects, four from group O subjects. The anti-B sera reacting with the acquired B antigen are always a mixture of two kinds of antibodies: a fraction that is only reactive with B antigen, another that is cross-reactive with B and acquired B antigens. In some sera, especially those coming from group O subjects, there is, in addition, a potent antibody of polyagglutination for acquired B red cells. The polyagglutinability associated with acquired B red cells is analysed. According to the results obtained using lectins, four red cell samples are merely acquired B, the three others are acquired B + Tk. The polyagglutinability associated with Tk transformation is non sensitive to acetylation of red cells. The polyagglutinability specific for acquired B is sensitive to acetylation but appears complex in itself. According to the reactivity of selected sera for acquired B samples and the studies of inhibition with simple sugars, there are at least two antigens involved. One of them is present in all of the acquired B samples and it is likely to have arisen from the action of a deacetylase on a structure including N-acetylgalactosamine.