P-gp, MRP, LRP, Bcl-2, and Bax proteins play an important role in themultidrug resistance of leukemic cells. P-gp, MRP, and LRP proteins decrease the intracellular drug concentration, Bcl-2 and Bax proteins influence the apoptosis process. The overexpression of some of these proteins is associated with poor prognosis of leukemia. The aim of this study was to find the relationship between some multidrug resistance markers and some clinical and laboratory parameters. We compare also P-gp expression between acute myeloid leukemia (AML) FAB subgroups M0–M6. Methods and Results. With use of flow cytometry we measured the expression of P-gp, MRP, LRP, Bcl-2, and Bax proteins in acute myeloid leukemia patients cells. The study proved the association between blast percentage and P-gp protein expression (p=0,015) and the association between blast percentage and Bcl-2 protein expression (p=0,041). It was also shown the tendency of the LRP protein expression to associate with higher age of patients (p=0,062). Another correlation between MRP and Bax expression (p=0,006), as well as between LRP and Bax expression was found (p=0,034). In AML M0 FAB subgroup of patients the trend to higher P-gp protein expression was observed. Conclusions. The laboratory methodology to multidrug resistance markers detection was introduced. Some relations between multidrug resistance markers playing role in acute myeloid leukemia patients prognosis were suggested.

        Key words: multidrug resistance, acute myeloid leukemia, P-gp, MRP, LRP, apoptosis, Bcl-2, Bax, flow cytometry.