A Case of Acute Leukemia Remitted by Adding Cyclosporin-A Previously Failed with Induction Therapy

ABSTRACT

Clinical chemotherapy refractoriness is characterized by resistance to multiple drugs. Multidrug resistance(MDR) is caused by over-reactivity of a unidirectional drug efflux pump, transmembrane glycoprotein(P-glycoprotein), which is encoded by the MDR1 gene. P-glycoprotein leads to increased drug efflux and decreased intracellular drug concentration. Clinical trials that attempt to reverse or modulate MDR have been done. Cyclosporin-A and verapamil are the most extensively studied agents and several trials of cyclosporin-A as a MDR modulator have been reported. We report a case of an 8-year-old girl with acute mixed type leukemia who failed to respond 3 times to remission-induction therapy. It led us to conclude she had multidrug resistance. We tried a fourth induction chemotherapy including cytarabine, idarubicin and 6-thioguanine to which cyclosporin-A was added. Then, she showed signs of severe bone marrow depression and fulminant perianal cellulitis. But she recovered and successfully achieved complete remission. The addition of cyclosporine could be useful in achieving complete remission for cases of acute leukemia that resist to usual chemotherapy. Futher observation including more cases will be needed to assess long-term survival and efficacy of adding cyclosporine.