Chromosome aberrations evaluated by comparative genomic hybridization in B-cell chronic lymphocytic leukemia: correlation with CD38 expression.
OBJECTIVE
B-cell chronic lymphocytic leukemia (B-CLL) results from the accumulation of monoclonal CD5+ B cells. Despite its homogeneity at cellular level, B-CLL is clinically heterogeneous. Clinical studies indicate that CD38+ B-CLL are characterized by a more aggressive clinical course than are CD38- B-CLL. On the basis of these studies and considering the established correlation between specific chromosome aberrations and the clinical course of B-CLL, it is possible that CD38+ B-CLL cases are also characterized by specific subsets of chromosomal alterations.


METHODS
Comparative genomic hybridization (CGH) was performed on purified B-cells from peripheral blood of 52 patients with B-CLL in order to detect chromosome imbalance. The immunophenotype of the patients, including CD38 expression, was also determined by flow cytometry. The results of CGH experiments were then compared with CD38 expression.


RESULTS
We found a clear correlation between the presence of chromosomal imbalances and CD38 expression: 13/16 CD38+ cases had chromosome imbalances, most of them (12/13) correlated with a poor prognosis. Among the CD38- B-CLL patients, only 8/36 displayed chromosome imbalances; the only three cases with loss in 13q as a single aberration, considered a good prognostic marker, were in this group. Moreover, we found that cytogenetic alterations were also more complex in the CD38+ B-CLL subset, since 9/10 with two or more aberrations were in the CD38+ group.


CONCLUSIONS
Collectively, the data reinforce the value of CD38 as a prognostic factor and indicate that genotypic/phenotypic features distinguish B-CLL subsets.
Ottaggio
Laura
L
Mutagenesis Laboratory, National Cancer Research Institute, largo Rosanna Benzi 10, 16132 Genoa, Italy. laura.ottaggio@istge.it
Viaggi
Silvia
S
Zunino
Annalisa
A
Zupo
Simona
S
Rossi
Edoardo
E
Spriano
Mauro
M
Abbondandolo
Angelo
A
Ferrarini
Manlio
M
D036541:ADP-ribosyl Cyclase / Q000378:metabolism*; D051997:ADP-ribosyl Cyclase 1; D000328:Adult; D000368:Aged; D015703:Antigens, CD / Q000378:metabolism*; D002869:Chromosome Aberrations; D002877:Chromosomes, Human / Q000648:ultrastructure; D020732:Cytogenetic Analysis; D005260:Female; D006801:Humans; D016130:Immunophenotyping; D015451:Leukemia, Lymphocytic, Chronic, B-Cell / Q000145:classification / Q000175:diagnosis*; D008297:Male; D008562:Membrane Glycoproteins; D008875:Middle Aged; D009693:Nucleic Acid Hybridization; D011379:Prognosis
D015703:Antigens, CD; D008562:Membrane Glycoproteins; D036541:ADP-ribosyl Cyclase; C498154:CD38 protein, human; D051997:ADP-ribosyl Cyclase 1