Detection of circulating and bone marrow myeloma cells in patients with multiple myeloma and its clinical significance

This study was aimed to investigate the correlation between circulating myeloma cells (CMC) and bone marrow myeloma cells (MMC) in patients with multiple myeloma (MM)and its clinical significance. Four-color flow cytometry was used to detect the percentage of CMC and MMC in 55 patients with MM. Other prognosis-associated factors such as β2 microglobulin (β2-MG), serum albumin (Alb), chromosomal abnormalities and renal function were simultaneously analyzed. The patients were divided into four groups: group A, in which CMC and MMC were simultaneously detected; group B, in which only MMC were detected; group C, in which only CMC were detected; group D, in which no myeloma cells were detected in peripheral blood or bone marrow. The results showed that the concentrations of β2-MG and creatinine were significantly increased and Alb markedly decreased in group A as compared with other groups. Statistical differences existed in the above-mentioned factors between patients with myeloma cells detected and not detected. The percentages of CMC or MMC in newly diagnosed, refractory and relapsed patients were apparently higher than those in patients with partial and complete remission, respectively. CMC were strikingly correlated with MMC. It is concluded that the percentages of CMC and MMC not only imply tumor load in MM patients, but also predict the progression of MM, espectively for patients with MM, in those patients CMC and MMC were simultaneously detected.