FLOW CYTOMETRIC ASSESSMENT OF MULTIDRUG RESISTANCE GENE IN ACUTE LEUKEMIA • -' •

Abstract

The multidrug resistance gene (MDRI) is frequently expressed in acute leukemias. MDRI is associated with resistance to chemotherapy in vitro and with a poor response rate in acute myeloid leukemia and acute lymphoblastic leukemia. In this study, the prognostic value ofMDRI expression was investigated in relation to other patient characteristics with respect to response and survival.

Twenty-five leukemic patients aged 8 months- 55 years were used m the study. A group of seven age and sex matched controls were also included. All patients were subjected to history taking, routine laboratory investigations including complete blood count and bone marrow examination. Diagnosis was established according to the morphological, cytochemical and immunophenotypic classification. All patients were assessed for the presence of P-glycoprotein (Pgp) on their leukemic blast cells by flowcytometry using R-PE conjugated mouse antihuman monoclonal antibody.

All patients were treated with standard induction and consolidation chemotherapy. Patients who achieved complete remission were termed group (A) and those who were non responders were termed group (B). All patients were classified again according to their mean fluorescence index into two groups: group I (high MFI) and group 2 (low MFI).