[Molecular biology follow-up of interferon therapy in patients with chronic myeloid leukemia]

In a prospective survey clinical haematological and molecular biological data of 31 patients with chronic myelogenous leukaemia (chronic phase, CML) observed in their haematological outpatient department were analyzed. During 1996 and 1999 a regular follow-up of the Philadelphia chromosome level in treated patients was performed with molecular biological techniques, i.e. with reverse transcription polymerase chain reaction (RT-PCR) and with fluorescence in situ hybridization (FISH) methods. During the follow-up period of 33 months from the 31 patients with CML (16 males, 15 females) 25 ones were treated with human recombinant interferon-alpha (IFN), however, six others were getting only hydroxyurea (HU). During this period in three patients allogen bone marrow transplantation was performed and seven ones expired (six out of them of blastic crisis). The quality of therapeutic response at cytogenetical level was determined by decrease of the bcr-abl level due to the treatment (non-responders, major, minor and complete cytogenetic remission groups). In nine patients (five from the IFN-group, four from the HU-group) achieved no cytogenetic therapeutic response (non-responders, 29%). However, in 13 patients a minor (bcr-abl range of 60-30%), and in nine patients a maior/complete (bcr-abl of 30-10%) cytogenetic response (42% and 29%, respectively) were detected. Moreover, the quality of cytogenetic response correlated with the haematological remission. The maior/complete cytogenetic response was durable in eigth patients. The improvement of the overall survival of patients with CML, the postpone of the fatal accelerated-blastic phase could be expected only from the early introduced, in individually adjusted and given in maximally tolerated dosage of interferon (3-5 million UI/m2/day). The qualitative (RT-PCR) and quantitative (FISH) detections of the Philadelphia chromosome are reliably reproducible up-to-date molecular biological methods getting relevant results, which could be very helpful in the planning, monitoring, in setting of optimal dosage of the interferon therapy of patients with CML, in addition in the judgement of the effectiveness of the therapy, in the reduction of adverse effects, as well as in forecasting of the cytogenetic progression.