Immunostimulation by cytosine-phosphate-guanine oligodeoxynucleotides in combination with IL-2 can improve the success rate of karyotype analysis in chronic lymphocytic leukaemia

Abstract

Purpose: To assess whether immunostimulatory cytosine-phosphate-guanine oligodeoxynucleotides (CpG-ODN) combined with interleukin-2 (IL-2) improves the number of mitotic metaphases and the detection rate of chromosomal abnormalities in chronic lymphocytic leukaemia (CLL).Materials and methods: Bone marrow specimens were collected from 36 patients with CLL. CLL cells were cultured with CpG-ODN type DSP30 plus IL-2 for 72 h, following which R-banding analysis was conducted. Conventional culture without the immunostimulant served as the control group. The incidence of genetic abnormalities was measured by fluorescence in situ hybridisation (FISH) using a panel of five specific probes: D13S25 (13q14.3), RB1 (13q14), P53 (17p13), ATM (11q22.3) and CSP12 (trisomy 12, +12).Results: In the control group, chromosome analysis achieved a success rate of only 22.2, and 11.1% of abnormal karyotypes were detected. After immunostimulation with DSP30 plus IL-2, chromosome analysis achieved a success rate of up to 91.6, and 41.6% of abnormal karyotypes were detected. FISH analysis detected 77.7% of abnormalities. FISH combined with CpG-ODN DSP30 plus IL-2 improved the detection rate of chromosomal abnormalities in CLL to 83.3%.Conclusion: CpG-ODN DSP30 combined with IL-2 is effective in improving the detection rate of chromosomal abnormalities in CLL cells. This combination with FISH analysis is conducive to increasing the detection rate of genetic abnormalities in CLL.