1. Increased frequency (12%) of circulating chronic lymphocytic leukemia–like B-cell clones in healthy subjects using a highly sensitive multicolor flow cytometry approach
- Author
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Alfonso Romero, María Jara-Acevedo, Julia Almeida, Cristina Teodosio, Wendy G. Nieto, Maria Luz Sanchez, Antonio López, Ana Henriques, Tomás Vega, Ana Rasillo, Marcos González, Paulino Fernández-Navarro, and Alberto Orfao
- Subjects
Adult ,Male ,Lymphocytosis ,Lymphocyte ,Chronic lymphocytic leukemia ,Immunology ,Gene Rearrangement, B-Lymphocyte, Heavy Chain ,Sensitivity and Specificity ,Biochemistry ,Immunophenotyping ,Flow cytometry ,Diagnosis, Differential ,medicine ,Humans ,Lymphocyte Count ,B cell ,Aged ,Aged, 80 and over ,B-Lymphocytes ,medicine.diagnostic_test ,business.industry ,Cell Biology ,Hematology ,Middle Aged ,Flow Cytometry ,medicine.disease ,Leukemia, Lymphocytic, Chronic, B-Cell ,medicine.anatomical_structure ,Monoclonal ,Disease Progression ,Monoclonal B-cell lymphocytosis ,Female ,medicine.symptom ,Clone (B-cell biology) ,business ,Precancerous Conditions - Abstract
Monoclonal B-cell lymphocytosis (MBL) indicates the presence of less than 5 × 109/L circulating monoclonal B cells in otherwise healthy subjects. Recently, it has been reported that circulating chronic lymphocytic leukemia (CLL)–like B cells can be detected using 4- or 5-multicolor flow cytometry in 5% to 7% of adults with normal lymphocyte counts. We investigated the frequency of circulating monoclonal B cells in 608 healthy subjects older than 40 years with normal blood counts, using a highly sensitive 8-color flow cytometry approach and systematic screening for total PB leukocyte count higher than 5 × 106. We show that the frequency of PB monoclonal B cells is markedly higher than previously reported (12% for CLL-like B cells, found at frequencies of 0.17 ± 0.13 × 109 cells/L), the incidence progressively increasing with age. Most cases (62%) showed clonal B-cell levels below the maximum sensitivity of the techniques described by others (< 0.01%), supporting the notion that detection of MBL may largely depend on the sensitivity of the flow cytometry approach used.
- Published
- 2009
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