Flow cytometric DNA quantification in immunophenotyped cells as a sensitive method for determination of aneuploid multiple myeloma cells in peripheral blood stem cell harvests and bone marrow after therapy

The simultaneous measurement of DNA content and myeloma-related antigens (B -B4 or CD38) by flow cytometry is proposed as a method for the detection of aneuploid plasma cells in peripheral blood stem cell (PBSC) harvests and i n bone marrow after therapy. In 30 patients with initially detected aneuplo id myeloma cells we evaluated the bone marrow after therapy and in eight of these patients 23 PBSC harvests were analyzed. In 13 of 23 PBSC harvests a neuploid myeloma cells were detectable (range: 0.02-0.63%). In the bone mar row of the 30 patients aneuploid plasma cells were detectable in all sample s after chemotherapy (range: 0.12-35.70%) and after autologous PBSC transpl antation in two of three patients (0.21% and 0.03%). Furthermore the relati onship between diploid and aneuploid plasma cells can be evaluated, In the PBSC harvests the percentage of aneuploid plasma cells is significantly low er than that of diploid plasma cells (P = 0.006). In contrast, in bone marr ow the aneuploid plasma cells are predominant in most patients even after t herapy (24 of 30 patients; P = 0.0055). In the case of initially detected a neuploid myeloma cells, a contamination with malignant cells can be estimat ed with a simple dow cytometric method in PBSC harvests and in bone marrow after therapy.