In two of the seven cases with IgG positive cells which were submitted.
to trypsin treatment, we have shown the actual synthesis of an 5.1gM. We can conclude from the antibody induced redistribution experiments that these
IgG molecules were not bound to the 1gM receptors. The behavior of these
IgG during the redistribution process was similar to that of antibodies directed
against surface antigenic determinants22 and differed from the behavior of
antigen-antibody complexes.23 The nature of the surface antigenic determinants
which react with these IgG antibodies is unknown. We are currently
attempting to establish if leukemic antigens are involved. In view of the
high incidence of a positive Coomb’s test in cases of CLL with S.IgG, it is
conceivable that these patients produce antibodies directed against a blood
group antigen common to erythrocytes and lymphocytes.