RESUMO
AIM: To develop an original therapeutic strategy in Ph-positive acute lymphoblastic leukemia (ALL). MATERIAL AND METHODS: In November 2001 Hematological Research Center (HRC) initiated the study of chimeric BCR-ABL gene. During the first stage of the study (November 2001-July 2004), 18 primary ALL patients were recruited in HRC, from July 2004 to January 2005--16 patients in HRC, N.N. Burdenko Central Military Hospital, regional Samara hospital. The diagnosis of Ph-positive ALL was established in detection of translocation t(9;22) by standard cytogenetic test or fluorescent hibridization in situ with double signal (D-FISH), or by polymerase chain reaction with reverse transcription (RT-PCR). In detection of aberration of BCR-ABL gene the patients received stem hemopoietic cells, from June 2004 imatinib was added to chemotherapy in the period of induction and consolidation. RESULTS: Incidence rate of BCR-ABL-positive ALL by standard cytogenetic test and D-FISH makes up 20%, by RT-PCR--25%. Differences in chimeric transcripts detectability by different methods may be explained by different sensitivity of the methods. Complete hematological remissions were achieved in the majority of the patients (6 of 8) irrespective of imatinib administration. Achievement of molecular remission in BCR-ABL-positive ALL occurs also in standard chemotherapy but molecular remissions begin 2-4 months later than clinicohematological ones. CONCLUSION: In using imatinib combination with chemotherapy, molecular remission can be achieved simultaneously with hematological one. Long-term results will be analysed later.