[Application of CpG Oligodeoxynucleotide Immunostimulation in Chromosome Study of Chronic Lymphoblastic Leukemia].

Objective: To explore the value of CpG-oligonucleotide(CpG-ODN) immunostimulatory method in chromosome culture of chronic lymphocytic leukemia (CLL) cells and to compare the differences between related studies at home and abroad, so as to improve the success rate of CLL karyotype culture and the detection rate of abnormal karyo-types.

Methods: Bone marrow samples from 82 CLL patients were collected and cultured with phytohemagglutinin (PHA), CpG-oligonucleotide plus interleukin-2 (CpG-ODN DSP30+IL-2) for 72 hours. Chromosomes were prepared and analyzed by conventional cytogenetics (CC). Meanwhile, D13S25, Rb1, ATM, p53 and CSP12 probes were used for interphase fluorescence in situ hybridization (iFISH) test. The differences of chromosome culture and iFISH test results between two cell stimulants were compared.

Results: The success rate of karyotype culture in PHA and CpG-ODN DSP30+IL-2 immunostimuli (analyzable mitotic t >20) was 90.2% (74 cases), 68.3% (56 cases) respectively, and the detection rate of abnormal karyotype was 13.5% (10 cases) and 46.4% (26 cases), respectively. The success rate of karyotype culture in PHA group was significantly higher than that in CpG-ODN DSP30+IL-2 group (P=0.01). The detection rate of abnormal karyotypes in CpG-ODN DSP30+IL-2 group was significantly higher than that in PHA group, and the difference was statistically significant (P=0.003). The detection rate of abnormal karyotypes in iFISH group was 74.4% (61 cases), which was significantly higher than that in CpG-ODN DSP30+IL-2 group (P=0.000). iFISH detection could verify the abnormalities detected by CC analysis.

Conclusion: Application of CpG-ODN DSP30+IL-2 immunostimulation method in culture of CLL cells can enhance the detection rate of abnormal karyotypes, especially the detection of various translocations suggesting poor prognosis.