Objective To monitor the expression patterns of bcr-abl in chronic myeloid leukemia (CML) patients during treatment with imatinib mesylate and evaluate the detection of MRD by RQ-PCR method. Methods The ABI Prism 7500 Sequence Detection System using Taqman fluorogenic probes was used to quantify target gene. bcr-abl mRNA was detected by RQ-PCR in 106 CML patients. The normalized quotient (NQ) of bcr-abl mRNA was calculated as followings: NQ=bcr-abl mRNA copy numbers/abl mRNA copy numbers. Results The NQ of BCR-ABL mRNA was well correlated with the progression of disease and the number of Ph+ cell (r =0.9824 and 0.9346, respectively). The NQ was decreased rapidly in 62 patients and kept in low level for a long time, and only 2 of them were relapsed. For 8 patients, after treatment the NQwere decreased initially and increased sharply, 7 of them were relapsed after 5-9 months. After treatment the NQ of 31 patients were still>0.1, 11 patients were relapsed after a short remission and 7 were ineffective or progression. Out of 5 patients whose NQ were fluctuated and had little regularity, but all of them had a continuing remission. Conclusion RQ-PCR is a more sensitive technique in the detection of bcr-abl fusion gene.It is an important method to monitor the tumor cell during the treatment with imatinib mesylate in CML patients.

Adult ; Aged ; Arsenicals ; pharmacology ; therapeutic use ; Bone Marrow Cells ; drug effects ; metabolism ; DNA Methylation ; drug effects ; Female ; Humans ; Inhibitor of Differentiation Proteins ; metabolism ; Male ; Middle Aged ; Myelodysplastic Syndromes ; metabolism ; therapy ; Oxides ; pharmacology ; therapeutic use ; Treatment Outcome ; Young Adult