[Detection of common fusion transcript levels in untreated leukemia patients by real-time quantitative RT-PCR technique].

Objective To evaluate levels of common specific fusion transcripts M-bcr-abl,m-bcr- abl,TEL-AML1,AML1-ETO,PML-RARα,CBFβ-MYH11 in untreated leukemia patients.Methods Spe- cific fusion transcript levels were detected by TaqMan-based real-time quantitative RT-PCR technique in a to- tal of 208 samples,including 195 bone marrow samples from 50 M-bcr-abl(+)chronic phase-chronic mye- loid leukemia(CML-CP),10 M-bcr-abl(+)acute lymphoblastic leukemia(ALL),19 m-bcr-abl(+)ALL, 11 TEL-AMLl(+)ALL,30 AML1-ETO(+)acute myeloid leukemia(AML),58 PML-RARα(+)acute promyelocytic leukemia(APL)and 17 CBFβ-MYH11(+)AML patients and 13 peripheral blood samples from 13 M-bcr-abl(+)CML-CP patients,abl was chosen as internal control gene.Fusion transcript level was calculated as fusion transcript copies/abl transcript copies in percentage.Results Bone marrow and pe- ripheral blood samples of CML-CP patients had similar M-bcr-abl fusion transcript levels(median 30% vs 35%,P0.05).M-and m-bcr-abl(median 64% vs 54%)levels were similar in ALL patients(P0.05), M-bcr-abl level was significantly higher in ALL than CML-CP patients(P0.001).Median TEL-AML1 level was 228% in ALL patients.Among AML patients,AML1-ETO level was significantly higher than CBFβ- MYH11 and PML-RARα levels(median 388% vs 145%,388% vs 47%,all P0.001),CBFβ-MYH11 level was significantly higher than PML-RARα level(P0.001).Fusion transcript levels of L-,V-and S- type PML-RARα were 45%,44% and 55%,respectively.L-type was significantly lower than S-type(P= 0.04).Conclusions Fusion transcript levels in untreated leukemia patients were different and patient-to-pa- tient variations did exist.Detection of fusion transcript levels in untreated leukemia patients not only provides baseline for minimal residual disease monitoring and treatment evaluation but also enable the comparison in in- ter-laboratory data.