Background: Alpha interferon can induce complete cytogenetic responses (CGR) in nearly 25% of chronic myeloid leukemia (CML) patients, but few of them obtain molecular responses (i.e. disappearance of the chimeric RNA bcr-abl). The incidence and evolution of this response are not well known.
Patients and methods: The molecular response has been explored in six CML patients, four in first chronic phase and two in relapse after bone marrow transplantation, who have obtained durable and sustained CGR. Bone marrow samples have been analyzed by double step RT-PCR. Results have been correlated with clinical and karyotype findings.
Results: Twenty nine samples have been studied. Every patient in first chronic phase CML have obtained molecular response, but this response has not been persistent. One of the patients with relapsing CML after showed transient PCR negativity, whereas persistent PCR positivity was detected in the other one.
Conclusions: Interferon alpha can induce complete molecular responses in CML patients, but in this study this responses have been fluctuant in all the patients.