B lymphocyte markers in multiple myeloma and related plasma cell dyscrasias.

Multiple myeloma and benign monoclonal gammopathies are regarded as monoclonal B cell proliferations in which B lymphocyte maturation is blocked in the final stages of the differentiation cycle. "Blocked" cells accumulate in the body and produce large quantities of immunoglobulins. These are monoclonal, because they come from a monoclonal cell stock. This study presents the results of peripheral B lymphocyte and marrow plasma cell typing designed to reveal the postulated isotypical relationship of the proliferating cells and the serum paraprotein. A good, though not absolute correlation between the two immunoglobulins was noted in most patients. The data, however, was not used in the diagnosis and treatment of these diseases. Further studies with MoAb's will, perhaps, provide a finer subclassification of the B lymphocyte proliferation diseases and assist in their diagnosis and treatment.