Comparison of Standard Prognostic Factors with the Deletion of 13q14 Detected by Interphase Fluorescence in Situ Hybridization on Separated and Unseparated Bone Marrow Cells in Multiple Myeloma

Overview

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. 

Key words:
multiple myeloma, magnetic-activated cell separation, interphase fluorescence in situ hybridization, 13q14 deletion, prognostic factors.