Detection of 13q abnormalities in multiple myeloma using immunomagnetically selected plasma cells

Area of Science:

• Hematology
• Cytogenetics
• Molecular Diagnostics

Background:

• Accurate prognostic evaluation is crucial for multiple myeloma (MM) patient stratification and therapy.
• Chromosomal abnormalities, such as the 13q14 deletion, are important prognostic markers in MM.

Purpose of the Study:

• To evaluate the efficacy of interphase fluorescence in situ hybridization (FISH) on immunomagnetically selected myeloma cells for detecting the 13q14 deletion.
• To compare the detection rate of the 13q14 deletion in unselected bone marrow (BM) cells versus selected myeloma cells.

Main Methods:

• Studied 13 bone marrow samples from 12 multiple myeloma patients.
• Utilized chromosomal G-banding and interphase FISH on both cell-nonspecific samples and CD138+ selected myeloma cells via magnetic-activated cell separation (MACS).
• Assessed purity and viability of magnetically separated myeloma cell suspensions.

Main Results:

• Magnetic separation yielded high-purity (mean 97.6%) and high-viability (mean 98.0%) myeloma cell suspensions.
• Interphase FISH detected the 13q14.3 deletion in 38.5% of cell-nonspecific samples.
• Detection rate of the 13q14.3 deletion increased to 69.2% in enriched myeloma cell suspensions.

Conclusions:

• Interphase FISH on immunomagnetically selected multiple myeloma cells significantly increases the detection rate of the 13q14 deletion.
• This enhanced detection improves prognostic evaluation and therapeutic stratification for MM patients.
• The MACS technique provides a reliable method for enriching myeloma cells for cytogenetic analysis.