The clinical significance of multidrug resistance gene (mdr1) expression in acute leukemia

Objective: To study the clinical significance of multidrug resistance gene expression in acute leukemia. Methods: The relationships between drug resistance of leukemia cells and prognosis, multidrug resistance gene (mdr1) were examined in 85 patients with acute leukemia and 20 normal controls by reverse transcriptase poly-merase chain reaction (RT-PCR). Results: The mdrl positive rate in untreated group was 44.7%. The complete remission (CR) rate of mdr1 positive patients (23.9%) was significantly lower than that of mdr1 negative patients (88.5%) ( P <0.005). The mdr1 expression level in relapsed-refractory group was higher than that of CR group. A gradually increased mdr1 mRNA level in CR patients indicated early relapse. Conclusion: The mdr1 positive rate in normal control and long-term survival patients was very low. The mdr1 expression was correlated with French-American-British Cooperative Group (FAB) classification. The mdr1 expression level was correlated with chemotherapeutic effect and prognosis. It is an unfavorable prognostic factor for patients with acute leukemia.