title: Multidrug resistance in B-cell chronic lymphocytic leukemia.
abstract: Multidrug resistance (MDR) was investigated in peripheral blood cells isolated from 40 patients with B cell chronic lymphocytic leukemia (B-CLL) and from 7 healthy volunteers, using a flow cytometric assay that detects cellular efflux of the fluorescent dye rhodamine 123 (Rh 123), which has been demonstrated to be transported from the cell by the P-glycoprotein pump. The proportion of B leukemic cells effluxing Rh 123 and thus displaying MDR was low (14 +/- 17%) in B-CLL and in only 4 cases did the contingent of B leukemic cells showing MDR represent more than 30% of the total leukemic cells. In contrast, a higher proportion of cells effluxing Rh 123 (44 +/- 13%) was demonstrated in normal B lymphocytes. No statistical correlation was found between the number of leukemic B cells displaying MDR and clinical parameters or previous treatment. These results clearly suggest that MDR activity is usually low in B-CLL.
mesh_terms: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1 / Q000097:blood* / Q000235:genetics; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D018432:Drug Resistance, Multiple / Q000235:genetics; D019008:Drug Resistance, Neoplasm / Q000235:genetics; D005434:Flow Cytometry; D005455:Fluorescent Antibody Technique; D015870:Gene Expression; D006801:Humans; D016130:Immunophenotyping; D015451:Leukemia, Lymphocytic, Chronic, B-Cell / Q000097:blood* / Q000188:drug therapy; D007963:Leukocytes, Mononuclear / Q000737:chemistry / Q000473:pathology; D008875:Middle Aged; D016133:Polymerase Chain Reaction; D012235:Rhodamines
chemical_list: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D012235:Rhodamines