Dietrich Wilhelm Beelen

Estimating the relapse stage in chronic myeloid leukaemia patients after allogeneic stem cell transplantation by the amount of BCR-ABL fusion transcripts detected using a new real-time polymerase chain reaction method

We have used a new single‐step real‐time reverse transcription polymerase chain reaction (RT‐PCR) method to quantify BCR‐ABL transcripts, thereby estimating the relapse stage in chronic myeloid leukaemia patients after allogeneic transplants. In 402 samples from 172 patients, BCR‐ABL expression was determined and normalized, using the GAPDH housekeeping gene product as an endogenous reference. In our real‐time RT‐PCR assay, serial dilutions of RNA of the K562 cell line remained positive down to 7·5 pg. The median normalized BCR‐ABL amount differed significantly (P < 0·001) between the various disease stages and was 0·06% (range 0·001–1·55%), 3·2% (range 1·4–5·6%) and 21·5% (range 6·8 −827%) in 17 patients with a molecular relapse, in eight patients with a cytogenetic relapse and in 10 patients with a haematological relapse respectively.