Abstract
Monoclonal B-cell lymphocytosis (MBL) is a hematologic condition wherein small B-cell clones can be detected in the blood of asymptomatic individuals. Most MBL have an immunophenotype similar to chronic lymphocytic leukemia (CLL), and CLL-like MBL is a precursor to CLL. We used flow cytometry to identify MBL from unaffected members of CLL kindreds. We identified 101 MBL cases from 622 study subjects; of these, 82 individuals with MBL were further characterized. In all, 91 unique MBL clones were detected: 73 CLL-like MBL (CD5+ CD20dim sIgdim), 11 atypical MBL (CD5+ CD20+ sIg+) and 7 CD5neg MBL (CD5neg CD20+ sIgneg). Extended immunophenotypic characterization of these MBL subtypes was performed, and significant differences in cell surface expression of CD23, CD49d, CD79b and FMC-7 were observed among the groups. Markers of risk in CLL such as CD38, ZAP70 and CD49d were infrequently expressed in CLL-like MBL, but were expressed in the majority of atypical MBL. Interphase cytogenetics was performed in 35 MBL cases, and del 13q14 was most common (22/30 CLL-like MBL cases). Gene expression analysis using oligonucleotide arrays was performed on seven CLL-like MBL, and showed activation of B-cell receptor associated pathways. Our findings underscore the diversity of MBL subtypes and further clarify the relationship between MBL and other lymphoproliferative disorders.
Original language | English (US) |
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Pages (from-to) | 1459-1466 |
Number of pages | 8 |
Journal | Leukemia |
Volume | 25 |
Issue number | 9 |
DOIs | |
State | Published - Sep 2011 |
Keywords
- B-cell immunology
- Chronic lymphocytic leukemia
- gene expression profiling
- immunophenotype
- monoclonal B lymphocytosis
ASJC Scopus subject areas
- Hematology
- Oncology
- Cancer Research