The aim of this study was to evaluate the level of MDRI gene expression in bone marrow and/or peripheral blood samples in 92 AML patients in relation to their prognosis. The analyzed group was stratified according to presence or absence of prognostically favorable aberrations (PFAs), such as t(15;17) with PML/RAR alpha fusion gene, t(8;21) with AML1/ETO fusion gene or inv(16)/ t(16;16) with CBF beta/MYH11 fusion gene.
These prognostically favorable aberrations were detected by RT-PCR and/or standard cytogenetic techniques. MDRI expression wasdetectedby semiquantitative comparative RT-PCR using software-based evaluation.
The levels of MDRI expression in the bone marrow predicted induction of complete remission in the whole group of analyzed patients (P = 0.032). They were significantly lower in PFA negative patients who achieved complete remission compared to those who failed to achieve complete remission (P = 0.008).
In PFA negative patients, MDRI expression was higher when compared to PFA positive patients (P = 0.055). No such difference was found when analyzing peripheral blood samples.
Our experiments showed no impact of MDRI expression in bone marrow or peripheral blood cells on overall survival (P = 1.000 and P = 0.903 respectively). In summary, the present study shows the prognostic impact of MDRI expression on induction of complete remission in AML patients.
We confirmed that MDRI overexpression is an unfavorable prognostic factor in AML, which may help to stratify the risk rate of PFA negative patients. In future studies, quantitative detection of MDRI expression might be a valuable tool to predict prognosis in this patient subset