Seguimiento citogenético y molecular en pacientes con leucemia mieloide crónica y trasplante alogénico de médula ósea

The genetic hallmark of chronic myelogenous leukemia (CML) is the t(9;22)(q34;q11), this gene fusion leads to the expression of chimeric BCR/ABL messenger RNA (mRNA), this marker is an attractive target for monitoring minimal residual disease (MDR) after bone marrow transplantation (BMT). The RT-PCR assays has become widely used for monitoring MDR after BMT for CML. We reported the cytogenetic and molecular findings in follow-up samples from 15 CML patients undergoing BMT. All 15 patients investigated before BMT by cytogenetic and RT-PCR were positive for Ph1 chromosome and BCR/ABL transcripts. Ten patients in complete remission presented for >12 month BCR/ABL transcript negative and karyotype normal. In five patients the RT-PCR nested for BCR/ABL were positive, three developed disease recurrence, one died by relapse, the other case with BCR/ABL+ for >12 months received donor lymphocyte infusion (DLI), then he has complete remission. We concluded that cytogenetic analysis is limited and insufficient in the monitoring of BMT and the RT-PCR provide reliable information on residual tumor burden in CML patients with BMT. The prognostic significance of a qualitative BCR/ABL can be refined by quantitative assays and this may target patients who would benefit from early intervention therapeutic.