A Practical Approach to the Detection of Prognostically Significant Genomic Aberrations in Multiple Myeloma

Abstract

Multiple myeloma (MM) is a malignancy of differen-Multiple myeloma (MM) is the prototypic monoclonal Bcell neoplasm that is derived from the autonomous proliferation of plasma cells and associated with paraprotein production and osteolytic bone lesions. MM primarily affects middle-aged to elderly patients. Blacks and males are affected more often than whites and females. 1 MM has remained an incurable disease, and effective therapeutic approaches are urgently required for patients with MM at different risk groups. Standard prognostic factors include serum ␤ 2 -microglobulin, C-reactive protein, bone marrow plasma cell morphology, and plasma cell proliferation (plasma cell labeling index). 1-3 These factors are independently associated with prognosis of patients with MM. Recently, there is considerable interest in characterizing genomic markers to establish prognostic models that allow a better estimation of an individual patient's prognosis.Chromosomal abnormalities are among the most important prognostic parameters for patients with MM. Of particular note, deletions of 13q remain independent adverse prognostic factors. 4 -6 However, conventional karyotyping has been hampered by the slow growth of MM cells in cell cultures, and chromosomal abnormalities are often missed by this technique. Of the cases studied, 50 to 70% showed normal karyotypes originating from the myeloid elements. 7-11 Therefore, cell-targeting methods are essential for the analysis of genomic aberrations in MM.Fluorescent in situ hybridization (FISH) allows detection of chromosomal aberrations in both actively dividing cells and interphase nuclei. Recently, the cytoplasm immunoglobulin (Ig) enhanced interphase FISH has been used to detect the most common genomic abnormalities in 351 patients with MM, including deletions of 13q14 and 17p13.1 and 14q32 translocations [t(4,14)(p16;q32), t(14;16)(q32;q23), and t(11;14)(q13;q32)]. 12 Genomic aberrations have been detected in 54.2% of the tested population for 13q14 deletions, 33.1% for 14q32 translocations, and 10.7% for the 17p13.1 deletion. 12 Importantly, three distinct prognostic groups have been identified, including those with a median survival time of 24.7 months [the t(4;14) and/or t(14;16), and/or 17p13.1 deletion], 42.3 months [13q14 deletions without the t(4;14), t(14;16), or 17p13.1 deletion], and 50.5 months [only the

Fluorescence in Situ Hybridization Analysis of Immunoglobulin Heavy Chain Translocations in Plasma Cell Myeloma Using Intact Paraffin Sections and Simultaneous CD138 Immunofluorescence

“…6,9,25 Others have used antibody-based sorting techniques to purify plasma cells from the bone marrow aspirate before FISH analysis. 7,26,27 Recently, another technique was proposed using an initial May-Grunwald Giemsa stain with mapping of plasma cells by image analysis software, followed for subsequent FISH analysis of the previously mapped plasma cells. 28 However, cell sorting and image analysis techniques both involve cumbersome protocols not routinely performed in most pathology laboratories.…”

Metaphase Harvest and Cytogenetic Analysis of Malignant Hematological Specimens

“…Interphase FISH allows detection of targeted abnormalities in nondividing cells, but is still hampered by the small number of plasma cells in bone marrow specimens. Interphase FISH in conjunction with cell-targeting methods has been considered the best approach for the detection of chromosomal aberration in MM, i.e., combining interphase FISH with immunofluorescence detection of the cytoplasmatic Ig light chain or cell sorting by CD138 microbeads (Chen et al, 2005;Slovak et al, 2005).…”

The Research on the CD138 Immune Magnetic Beads for Multiple Myeloma Cells Sorting

“…After sorting, the sensitivity of the chromosome abnormality detection of MM cells is greatly improved. Chen etc [2] compared the chromosome abnormality of sorting cells and non-sorting cells. As a result, the former had higher sensitivity.…”