TY - JOUR
T1 - Immunogenetics shows that not all MBL are equal
T2 - The larger the clone, the more similar to CLL
AU - Vardi, Anna
AU - Dagklis, Antonis
AU - Scarfo, Lydia
AU - Jelinek, Diane
AU - Newton, Darren
AU - Bennett, Fiona
AU - Almeida, Julia
AU - Rodriguez-Caballero, Arancha
AU - Allgood, Sallie
AU - Lanasa, Mark
AU - Cortelezzi, Agostino
AU - Orlandi, Ester
AU - Veronese, Silvio
AU - Montillo, Marco
AU - Rawstron, Andy
AU - Shanafelt, Tait
AU - Orfao, Alberto
AU - Stamatopoulos, Kostas
AU - Ghia, Paolo
N1 - Publisher Copyright:
© 2013 by The American Society of Hematology.
PY - 2013/5/30
Y1 - 2013/5/30
N2 - 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 3 109/L circulating clonal B cells. However, the clonal size in MBL is extremely variable and allows discrimination of two distinct entities (highcount [HC] and low-count [LC]-MBL) based on a cutoff value of 0.5 3 109/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.
AB - 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 3 109/L circulating clonal B cells. However, the clonal size in MBL is extremely variable and allows discrimination of two distinct entities (highcount [HC] and low-count [LC]-MBL) based on a cutoff value of 0.5 3 109/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.
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U2 - 10.1182/blood-2012-12-471698
DO - 10.1182/blood-2012-12-471698
M3 - Article
C2 - 23596047
AN - SCOPUS:84879774711
SN - 0006-4971
VL - 121
SP - 4521
EP - 4528
JO - Blood
JF - Blood
IS - 22
ER -