Woman Exhibits Two Different CLL Clones at Once

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Am J Clin Pathol. 2006 Jul;126(1):1-6.

Molecular characterization of chronic lymphocytic leukemia with two

distinct cell populations: evidence for separate clonal origins.

Chang H, Cerny J.

Department of Laboratory Hematology, Laboratory Medicine and

Pathobiology, University Health Network and University of Toronto,

Toronto, Canada.

We report a case of an elderly woman with persistent lymphocytosis in

whom flow cytometric immunophenotyping revealed 2 distinct clonal B-

cell populations with different light chain restrictions. One clone

was CD19+ (dim), CD5+ (bright), CD23+ (moderate), and k+; the other

clone was CD19+ (moderate), CD5+ (bright), CD23+ (dim), and l+.

We separated the 2 clones by flow cytometry from peripheral blood

lymphocytes for further molecular and cytogenetic analysis.

Polymerase chain reaction (PCR) analysis of the immunoglobulin heavy

chain (IgH) genes revealed that the clones had bands of slightly

different size. The PCR products of the framework 3 (FR3) region were

cloned, and sequence analysis confirmed that each population had

distinct, clone-specific IgH gene rearrangements. Fluorescence in

situ hybridization (FISH) analysis revealed trisomy 12 in the l-

restricted B-cell clone, whereas the k-restricted population had

normal FISH patterns.

Our results demonstrated that the immunophenotypically different cell

populations originated from 2 separate clones.

PMID: 16753602 [PubMed - in process]