DNA content of human myeloma cells

DNA flow cytofluorometry of bone marrow cells from 29 patients with multiple myeloma disclosed a 55% incidence of aneuploid cell populations with a DNA index between the diploid and the tetraploid regions (2-4 C) and a mean value of 2.5 C. The bone marrow of these patients demonstrated a correlation between the proportion of aneuploid and morphologically identifiable myeloma cells, which indicates a monoclonal pattern in the aneuploid cases without additional diploid myeloma cell clones. In the present patient material no statistically significant relation was found between diploid and aneuploid cases as regards the type of monoclonal immunoglobulin. Further, there was no difference between the diploid and aneuploid cases as regards myeloma cell differentiation, myeloma cell [3H]-thymidine labeling index or response to melphalan treatment.