Immunogenetics shows that not all MBL are equal: the larger the clone, the more similar to CLL.

Journal Article (Journal Article)

Chronic lymphocytic leukemia (CLL) -like monoclonal B-cell lymphocytosis (MBL) shares common immunophenotype and cytogenetic abnormalities with CLL, from which it is discriminated by a cutoff value of 5 × 10(9)/L circulating clonal B cells. However, the clonal size in MBL is extremely variable and allows discrimination of two distinct entities (high-count [HC] and low-count [LC]-MBL) based on a cutoff value of 0.5 × 10(9)/L clonal B cells. HC-MBL is associated with lymphocytosis and progresses to CLL requiring treatment at a rate of 1.1% per year, whereas LC-MBL is found in the general population only through high-sensitivity techniques and carries limited, if any, risk of progression. We performed an immunogenetic profiling of 333 cases with CLL-like MBL supplemented by detailed comparisons with CLL, focusing especially on CLL Rai stage 0 (CLL-0). LC- and HC-MBL had similar somatic hypermutation status, yet different IGHV gene repertoires and frequencies of B-cell receptor (BcR) stereotypy. In particular, stereotyped BcRs were infrequent in LC-MBL and were often not CLL specific. In contrast, HC-MBL exhibited clear immunogenetic similarities to CLL-0. These findings indicate that LC-MBL may not represent a true preleukemic condition, thus differing from HC-MBL/CLL-0 in which the identification of factors endowing malignant potential is strongly warranted.

Full Text

Duke Authors

Cited Authors

  • Vardi, A; Dagklis, A; Scarfò, L; Jelinek, D; Newton, D; Bennett, F; Almeida, J; Rodriguez-Caballero, A; Allgood, S; Lanasa, M; Cortelezzi, A; Orlandi, E; Veronese, S; Montillo, M; Rawstron, A; Shanafelt, T; Orfao, A; Stamatopoulos, K; Ghia, P

Published Date

  • May 2013

Published In

Volume / Issue

  • 121 / 22

Start / End Page

  • 4521 - 4528

PubMed ID

  • 23596047

Electronic International Standard Serial Number (EISSN)

  • 1528-0020

International Standard Serial Number (ISSN)

  • 0006-4971

Digital Object Identifier (DOI)

  • 10.1182/blood-2012-12-471698


  • eng