title: Expression of multidrug resistance P-glycoprotein on peripheral blood mononuclear cells of patients with granular lymphocyte-proliferative disorders.
abstract: Some patients with granular lymphocyte-proliferative disorders (GLPD) have been reported to have an aggressive clinical course with a poor prognosis and to be refractory to chemotherapy. In this study, expression of multidrug resistance P-glycoprotein on peripheral blood mononuclear cells (PBMC) of 11 patients with GLPD was examined by staining with MRK 16, a monoclonal antibody that binds to an external epitope of P-glycoprotein, and with the dye rhodamine, a known substance to be excreted from the cells through P-glycoprotein. Among those tested, the PBMC of six of eight patients with T-cell-type GLPD as well as those of three of three patients with natural killer cell-type GLPD expressed P-glycoprotein significantly. Furthermore, PBMC of two of two patients were also poorly stained with the dye rhodamine, and the treatment of PBMC with either verapamil or quinidine, multidrug resistance-reversing agents, led to their increased staining, suggesting that these PBMC actively release chemotherapeutic agents.
authors.affiliation: Department of Biomolecular Science, Faculty of Science, Toho University, Chiba, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Yamamoto
authors.forename: T
authors.initials: T
authors.lastname: Iwasaki
authors.forename: N
authors.initials: N
authors.lastname: Watanabe
authors.forename: K
authors.initials: K
authors.lastname: Oshimi
authors.forename: M
authors.initials: M
authors.lastname: Naito
authors.forename: T
authors.initials: T
authors.lastname: Tsuruo
authors.forename: Y
authors.initials: Y
authors.lastname: Kobayashi
mesh_terms: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D000328:Adult; D000368:Aged; D015703:Antigens, CD / Q000032:analysis; D018956:CD5 Antigens; D004351:Drug Resistance; D005260:Female; D015333:Gene Rearrangement, beta-Chain T-Cell Antigen Receptor; D006801:Humans; D007963:Leukocytes, Mononuclear / Q000737:chemistry*; D008232:Lymphoproliferative Disorders / Q000097:blood* / Q000188:drug therapy; D008297:Male; D008562:Membrane Glycoproteins / Q000097:blood*; D008875:Middle Aged; D020112:Rhodamine 123; D012235:Rhodamines / Q000493:pharmacokinetics; D013601:T-Lymphocytes / Q000276:immunology*
chemical_list: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D015703:Antigens, CD; D018956:CD5 Antigens; D008562:Membrane Glycoproteins; D012235:Rhodamines; D020112:Rhodamine 123