The cellular localization of 6.6 S γ-globulins, β2A-globulins, γ1-macroglobulins and Bence Jones proteins was studied by immunohistochemical procedures in 21 patients with multiple myeloma or macroglobulinemia.
Each type of protein was identified by specific immunofluorescence in a variety of morphologic forms of malignant cells. Some cells were typically plasmacytic, some were lymphoid cells and others were immature forms. It was clear that γ, β2A, γ1M, and Bence Jones proteins were not associated exclusively with a single morphologic form of malignant cell. The variety of immunofluorescent positive cells in each patient was more restricted, however, than in a group of patients with a specific protein abnormality.
In patients with anomalous proteins, all or almost all of the malignant cells were found to contain the specific anomalous protein. The malignant cells contained either γ-myeloma protein, β2A-myeloma protein or γ1-macroglobulin in patients with these types of anomalous protein. Only one class of globulin was found in individual cells. In patients with Bence Jones proteins as the sole anomalous protein, all the malignant cells appeared to have Bence Jones protein. Where an anomalous serum globulin coexisted with Bence Jones proteins, indirect evidence indicated that the Bence Jones proteins and the larger globulin were formed in the same cells.