Search

Background: Cytogenetic abnormalities of chromosome 13 are emerging as important prognostic factors in multiple myeloma and have been associated with poor prognosis., Methods and Results: The occurrence of 13q14 deletion and other standard laboratory parameters were determined in 40 patients with multiple myeloma. We found that interphase fluorescence in situ hybridization using a locus specific probe for RB1 gene on immunomagnetically selected myeloma cells was more sensitive than non selected cells. The 13q14 deletion was found in 10 of 40 (25.0%) of bone marrow samples without cell selection and in 25 of 40 (62.5%) of samples with CD138+ enriched myeloma cells. Negative correlation was found between albumin and the 13q14 deletion in separated (p = 0.003) as well as in cells without selection (p = 0.010). No significant correlation was found in overall survival of separated and unseparated cells (p = 0.830; p = 0.260) and a similar result was obtained for treatment response after transplantation of separated cells (p = 0.520) or non-separated cells (0.190)., Conclusions: Our results confirm that immunomagnetic selection of CD138+ cells increases the probability of detection of the 13q14 deletion in bone marrow samples. The correlation was found between albumin and the 13q14 deletion in both of type of cells.

Accurate prognostic evaluation of patients with multiple myeloma (MM) is required for their stratification for more adequate therapy. Chromosomal G-banding and interphase fluorescence in situ hybridization (FISH) on cell-nonspecific samples and on myeloma cells selected by magnetic-activated cell separation (MACS) were used to study 13 samples from 12 multiple myeloma (MM) patients. Bone marrow (BM) samples were analysed using three approaches. Standard mitotic samples were prepared and analysed after G-banding. Interphase FISH was performed to detect the 13q14 deletion in unselected BM cells. In parallel, myeloma cells were selected from the BM using the CD138-specific antibody. The high-purity myeloma cell suspension was then analysed by interphase FISH for the 13q14 deletion. Magnetic separation yielded enriched myeloma cell suspensions with the mean viability of 98.0% (range: 97.0%-99.0%), and the purity of 97.6% (range: 87.2%-99.2%) as detected morphologically, and 85.2% (range: 44.8%-98.4%) as detected by immunophenotyping for CD138+ cells. Interphase FISH revealed the 13q14.3 deletion in 5 of 13 (38.5%) of cell-nonspecific samples and in 9 of 13 (69.2%) of enriched myeloma cell suspensions. In conclusion, interphase FISH on immunomagnetically selected MM cells increases the detection of the 13q14 deletion in BM samples from the patients with MM.