Clinical study on reversal of multidrug resistance in relapsed or refractory acute leukemias by cyclosporin A and interferon

Objective:To explore the clinical implication of reversal of multidrug resistance (MDR) by cyclos-porin A (CsA) and interferon-a (IFN-α). Method:The expression of P-170 were assaied in 50 cases of relapsed or refractory acute leukemias by means of immunocytochemistry (Avidin-Biotin complex, ABC) using a monoclonal antibody JSB-1 against P-170. The 34 cases who were the P-170 positive were randomly divided into two groups; trial group (chemotherapy plus CsA and IFN-a) and control group(chemotherapy alone). Result: The incidence of P-170 expression (68%) was higher in relapsed or refractory acute leukemias. The effective rate were 64. 7% and 23.5% respectively ( P 0. 05). Conclusion:CsA and IFN-o were safe and effective for reversal of MDR in relapsed or refractory acute leukemia.