Related Experiment Videos
Splenic marginal zone lymphomas appear to originate from different B cell types
David W Bahler1, J Ander Pindzola, Steven H Swerdlow
1Department of Pathology, University of Utah, Salt Lake City, Utah, USA. dhb10@utah.edu
The American Journal of Pathology
|July 11, 2002
Summary
Splenic marginal zone lymphomas (SMZLs) may arise from two distinct B cell types: naive B cells (IgD+, unmutated VH genes) or memory B cells (IgD-, mutated VH genes). This suggests dual origins and potential antigen selection in SMZL development.
Area of Science:
- Hematology
- Immunology
- Oncology
Background:
- Splenic marginal zone lymphomas (SMZLs) are typically associated with memory B cells, which usually possess mutated immunoglobulin heavy-chain variable (VH) genes.
- However, SMZLs often express IgD and IgM, markers more characteristic of naive B cells with unmutated VH genes, creating a paradox regarding their cell of origin.
Purpose of the Study:
- To investigate the cell of origin and pathogenesis of SMZLs.
- To clarify the dichotomy between VH gene mutation status and B cell marker expression in SMZLs.
Main Methods:
- Histological and immunophenotypic analysis of eight SMZL cases.
- Sequencing of rearranged VH genes to assess mutation status and gene segment usage.
Main Results:
- Four SMZL cases exhibited unmutated VH genes, consistent with a naive B cell origin, with three of these cases expressing IgD.
- The other four cases displayed mutated VH genes, supporting a memory B cell origin.
- A nonrandom usage of VH gene segments (VH1 or VH4 families) was observed in most cases, with specific segments (V1-2, V1-69, V4-34) frequently utilized.
Conclusions:
- SMZLs likely originate from two distinct B cell populations: naive marginal zone B cells and memory marginal zone B cells.
- The nonrandom VH gene usage suggests that antigen selection may play a role in the development of SMZLs.