Detection of residual bcr/abl translocation by polymerase chain reaction in chronic myeloid leukaemia patients after bone-marrow transplantation.

The polymerase chain reaction was used to evaluate minimum residual disease in chronic myelogenous leukaemia (CML) patients after bone-marrow transplantation, by amplification of the transcript of the specific bcr/abl hybrid gene. Strict precautions were taken to avoid contamination. Peripheral blood cells from 22 patients transplanted for haematological malignant disorders were analysed. The results were clearcut for positive controls (patients with CML in relapse) and negative controls (patients with malignant disorders other than CML). In 11 of 12 CML patients in clinical and cytogenetic remission the bcr/abl transcript was detected 3 months to 6 years after transplantation. Thus, it appears that cells expressing the bcr/abl mRNA are not eradicated from the blood of CML patients in complete clinical remission even years after bone-marrow transplantation.