Related Experiment Videos
Multiple independent immunoglobulin class-switch recombinations occurring within the same clone in myeloma
A Palumbo1, S Battaglio, M Astolfi
1Dipartimento di Medicina e Oncologia Sperimentale, Università di Torino, Italy.
British Journal of Haematology
|December 1, 1992
Summary
Multiple myeloma clonality can originate from pre-switch B cells, not just plasma cells. This finding impacts understanding the origins of this blood cancer.
Area of Science:
- Hematology
- Molecular Biology
- Oncology
Background:
- Multiple myeloma (MM) involves abnormal plasma cell expansion.
- The precise cellular origin of the clonogenic fraction in MM remains unclear.
- Distinguishing between plasma cells and pre-plasma cells as the source is critical.
Purpose of the Study:
- To investigate the cellular origin of clonality in multiple myeloma.
- To determine if the clonogenic fraction resides in plasma cells or earlier B cell precursors.
- To analyze immunoglobulin gene rearrangement patterns in MM bone marrow.
Main Methods:
- Examined immunoglobulin (Ig) gene rearrangement in bone marrow cells from MM patients.
- Utilized probes from the heavy chain J region (JH).
- Employed BamHI, EcoRI, and HindIII restriction enzymes to detect VDJ recombination.
Main Results:
- Clonal Ig gene rearrangement was detected in 23/39 MMs using BamHI, EcoRI, and HindIII.
- In 14/39 patients, BamHI and EcoRI failed to detect rearrangement, but HindIII consistently showed VDJ recombination.
- HindIII's consistent detection is attributed to its fragment's 3' end being upstream of the switch mu region, unaffected by switch recombination.
Conclusions:
- The clonogenic fraction in 35% of MM patients appears to originate from pre-switch B cells.
- These B cells differentiate into plasma cells, undergoing multiple independent switch recombinations.
- This suggests a more complex cellular origin for multiple myeloma than previously assumed.