In chronic lymphocytic leukemia, usually a monoclonal disease, multiple productive immunoglobulin heavy chain gene rearrangements are identified sporadically. Prognostication of such cases based on immunoglobulin heavy variable gene mutational status can be problematic, especially if the different rearrangements have discordant mutational status. To gain insight into the possible biological mechanisms underlying the origin of the multiple rearrangements, we performed a comprehensive immunogenetic and immunophenotypic characterization of 31 cases with the multiple rearrangements identified in a cohort of 1147 patients with chronic lymphocytic leukemia. For the majority of cases (25/31), we provide evidence of the co-existence of at least two B lymphocyte clones with a chronic lymphocytic leukemia phenotype. We also identified clonal drifts in serial samples, likely driven by selection forces. More specifically, higher immunoglobulin variable gene identity to germline and longer complementarity determining region 3 were preferred in persistent or newly appearing clones, a phenomenon more pronounced in patients with stereotyped B-cell receptors. Finally, we report that other factors, such as TP53 gene defects and therapy administration, influence clonal selection. Our findings are relevant to clonal evolution in the context of antigen stimulation and transition of monoclonal B-cell lymphocytosis to chronic lymphocytic leukemia.
- MeSH
- B-lymfocyty * MeSH
- chronická lymfatická leukemie * MeSH
- míra přežití MeSH
- mutace * MeSH
- nádorový supresorový protein p53 * genetika MeSH
- přestavba genů pro těžké řetězce B-lymfocytů * MeSH
- přežití po terapii bez příznaků nemoci MeSH
- somatická hypermutace imunoglobulinových genů * MeSH
- Check Tag
- mužské pohlaví MeSH
- ženské pohlaví MeSH
INTRODUCTION: Minimal residual disease (MRD) detection has become increasingly important for the assessment of therapy response in chronic lymphocytic leukemia (CLL). However, current MRD analysis methods, both molecular genetic and flow cytometric, are time-consuming and require experienced laboratory staff. METHODS: To reduce the demands of flow cytometric MRD detection in CLL, we have introduced a novel flow cytometric 8-color protocol. The MRD analysis results using this protocol were then compared with the commonly employed 4-color protocol and the molecular genetic (real-time quantitative allele-specific oligonucleotide IGH polymerase chain reaction; RQ-ASO IGH PCR) approach. RESULTS: Forty-two CLL patient samples were repeatedly analyzed after allogeneic stem cell transplantation (n = 20) or after fludarabine-based therapy (n = 22), and 100% concordance was found using both flow cytometric protocols. Furthermore, there was a strong correlation (r = 0.94) between flow cytometric and RQ-ASO IGH PCR results in MRD detection. CONCLUSION: Flow cytometry is less time-consuming, less financially demanding, and moreover, MRD assessment using our novel 8-color protocol is less complicated than the 4-color approach and molecular methods.
- MeSH
- chronická lymfatická leukemie krev patologie terapie MeSH
- dospělí MeSH
- homologní transplantace MeSH
- imunofenotypizace metody MeSH
- lidé středního věku MeSH
- lidé MeSH
- polymerázová řetězová reakce MeSH
- průtoková cytometrie metody MeSH
- reprodukovatelnost výsledků MeSH
- reziduální nádor diagnóza MeSH
- senioři MeSH
- senzitivita a specificita MeSH
- těžké řetězce imunoglobulinů genetika MeSH
- transplantace hematopoetických kmenových buněk MeSH
- Check Tag
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- mužské pohlaví MeSH
- senioři MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Publikační typ
- abstrakt z konference MeSH
