[Chromosomal aberrations detection in chronic lymphocytic leukemia by conventional cytogenetics using DSP30 and IL-2]

Objective: To study the value of unmethylated cytosine guanine dinucleotide oligodeoxynucleotide (DSP30) and IL-2 in the conventional cytogenetic (CA) detection of the chromosomal aberrations in chronic lymphocytic leukemia (CLL) . Methods: Bone marrow or peripheral blood cells of CLL patients were cultured with DSP30 plus IL-2 for 72 h, following which R-banding analysis was conducted. Fluorescence in situ hybridization (FISH) was performed in 85 patients. CA results were compared with data obtained by FISH. Results: Among 89 CLL patients, the success rate of chromosome analysis was 94.38% (84/89) . Clonal aberrations were detected in 51 patients (51/84, 60.71%) . Of them, 27 (27/51, 52.94%) were complex karyotype. Among 85 CLL patients tested by FISH, chromosomal abnormalities were detected in 74 (74/85, 87.06%) patients, of which 2 (2/74) patients were complex karyotypes, accounting for 2.70%. Of the 85 CLL patients examined by FISH, 50 had abnormal karyotype analysis, 30 had normal karyotype, 5 failed to have chromosome analysis. Among them, 25 cases showed clonal aberrations by FISH assay but normal by CA, and 4 cases were normal by FISH but displayed aberrations in chromosome analysis, and totally 78 (91.76%) cases with abnormality detected by the combination of the two methods. The frequency of 13q- abnormality detected by FISH was significantly higher than that by CA analysis (69.41%vs 16.67%, P<0.001) , while the frequency of 11q-,+12 and 17p- detected by two methods showed no significant difference (P>0.05) . The detection rate of complex abnormalities in conventional karyotype analysis was higher than that in FISH (50.98%vs 2.70%) . In addition, 11 low-risk and 9 intermediate-risk patients according to FISH results showed complex karyotype by cytogenetics, and were classified into high-risk cytogenetic subgroup. Conclusion: DSP30 and IL-2 are effective in improving the detection rate of CA in CLL patients (60.71%) and CA is more effective to detect complex karyotype. However, FISH had a higher overall abnormality detection rate (87.06%) than CA, especially for 13q-. The combination of CA and FISH not only enhanced the detection rate of clonal aberrations to 91.76%, but also provided more precise prognosis stratification for CLL patients, thus to provide more information for clinical implication.