Monoclonal B-Cell Lymphocytosis and Chronic Lymphocytic Leukemia

In a study of older adults, rates of progression from MBL to CLL were reassuringly low.

Sensitive flow cytometric techniques have been used to identify small populations of monoclonal B cells phenotypically identical to chronic lymphocytic leukemia (CLL) cells (positive for the expression of T-cell antigen CD5 and B-cell surface antigens CD19 and CD23, with κ or λ immunoglobulin light-chain restriction) in >3% of otherwise normal adults (mostly age >60; Blood 2002; 100:635). By definition, CLL-phenotype monoclonal B-cell concentrations >5000/mm³ are diagnostic of CLL, whereas lower concentrations are diagnostic of monoclonal B-cell lymphocytosis (MBL).

To determine whether chromosomal abnormalities associated with CLL also occur in CLL-phenotype MBL, investigators compared results of flow cytometry on peripheral blood samples f…

Reviewing Author

Michael E. Williams, MD

Disclosures

Consultant/Advisory BoardAbbVie; AstraZeneca; Beigene; Janssen; Pharmacyclics

Grant/Research SupportJanssen

Editorial BoardsAmerican Board of Internal Medicine (ABIM) Hematology Longitudinal Knowledge Approval Committee

Michael E. Williams, MD

Disclosures

Consultant/Advisory BoardAbbVie; AstraZeneca; Beigene; Janssen; Pharmacyclics

Grant/Research SupportJanssen

Editorial BoardsAmerican Board of Internal Medicine (ABIM) Hematology Longitudinal Knowledge Approval Committee