Real-time quantitative PCR monitoring of minimal residual disease in CML after treatment

Abstract

Objective To set up a real-time quantitative PCR approach for detection and quantification for bcr-abl transcripts in CML patients,and detect minimal residual disease (MRD) in CML by real-time quantitative PCR (RQ-PCR)and evaluate the significance of MRD detection.Methods The ber-abl.fusion gene expression in 80 patients with CML was analyzed by RQ-PCR. The patients were divided into three groups according to the different treatment, allogeneic hematopoietic stem cell transplantation group,imatinib group and hydroxyurea group. The change of bcr-abl fusion gene was monitored in CML patients before and after treatment.Results The average of RQ-PCR detection on newly diagnosed patients with CML in chronic phase was 6847.67 copies / 104 cells,the accelerated phase was 306 176.08 copies / 104 cells,and the average results were 944.33, 2.37, 0.29, 0 copies / 104 cells after allogeneic hematopoietic stem cell transplantation one month,6 months,12 months or 24 months respectively.The average of RQ-PCR detection after use imatinib mesylate 3 months was 3720.23 copies / 104 cells and not be detected after one year. The average was 7290.11 and 3143.24 copies / 104 cells after hydroxyurea treatment 0 and 9 months respectively.The difference in first two groups was not significant (t=1.74,P=0.17), but the difference between the third group and the first two groups was significant (t=3.74,P=0.01.t=2.97,P=0.02). The upregulation of bcr-abl transcript levels could be detected when disease progression. The transcripts level in accelerated phase was significantly higher than that in chronic phase. Conclusion RQ-PCR can be used to detect the MRD,monitor the treatment outcome,predict disease recurrence and give early intervention. Key words: Leukemia, myeloid, chronic; Minimal residual disease; Real-time quantitative PCR