A mixed staining patern was observed in three patients with W.M. Studies
of the newly synthetized S.IgM were undertaken as described above in one
of these three patients because of the known anti-IgG antibody activity of
the serum monoclonal 1gM. The results clearly showed that the 1gM molecules
present at the cell surface shared the antibody activity of the patient’s serum
1gM.23
proliferation was controlled by therapy, a low percentage of blood lymphocytes
(mean 9%) carried the monoclonal 5.1gM. The fluorescence pattern
was strinkingly heterogeneous in every patient. Control experiments ruled
out the possibility of a passive coating of serum 1gM on the lymphocytes
and proved the actual synthesis of 5.1gM by the cells.