Interphase Fluorescence In Situ Hybridization Detection of Cytogenetic Abnormalities in B-Cell Chronic Lymphocytic Leukemia.

The most frequent chromosomal abnormalities in B-cell chronic lymphocytic leukaemia (B-CLL) are deletions on 13q14 and 17p13, trisomy 12 and 14q32 rearrangement. Conventional metaphase cytogenetic analysis underestimates the frequency of specific chromosome aberrations in B-CLL due to the low rate of spontaneous mitoses and poor response to mitogen stimulation. The aim of this study was to investigate the incidence of chromosomal changes in bone marrow or peripheral blood cells (or both) of B-CLL patients using a molecular cytogenetic method, interphase fluorescence in situ hybridization (I-FISH). Probes for 13q14 (D13S319), 17p13 (P53 gene), the centromere of chromosome 12 (D12Z3) and 14q32 (Ig10 and Y6) were applied to detect chromosomal aberrations on bone marrow and peripheral blood smears from 83 B-CLL patients (60 male, 23 female,). Molecular cytogenetic aberrations were found in 60 (72.3%) cases, and 8 (9.6%) patients showed two kinds of abnormalities. The most frequent abnormalities detected in our patients was deletions of 13q14 in 34 cases (41.0%), followed by trisomy of chromosome 12 in 16 patients (19.3%), deletions of 17p13 in 10 patients (12%) and 14q32 rearrangement in 8 patients (9.6%). Statistical analyses were performed to correlate the molecular cytogenetic findings with Binet stages. No apparent differences in distribution were noted for anomalies del(13q14), del(17p13), +12 or 14q32 rearrangement among patients with various Binet stages. FISH was found to be a more rapid, exact and sensitive technique for the analysis of chromosome aberrations in CLL. FISH could provide accurate information of molecular cytogenetics for CLL.