title: Analysis of multidrug-resistance (MDR-1) glycoprotein and CD56 expression to separate monoclonal gammopathy from multiple myeloma.
abstract: Monoclonal gammopathy of undetermined significance (MGUS) is different from multiple myeloma (MM) by a low proliferation and by its indolent clinical course. In this study, two biological parameters were investigated which mark the transition from MGUS to MM, i.e. expression of the P-170 glycoprotein associated with the multidrug resistance phenotype (MDR-1) and expression of the natural killer cell antigen. CD56. Strong MDR-1 expression was found in plasma cells of 32/38 untreated MGUS as compared with 33/105 untreated MM stage I-III (84% v 32%, P < 0.001) and in 0/10 normal plasma cell samples. CD56 expression in high density was present in 43/57 analysed untreated MM but in none of 23 MGUS (78% v 0%, P < 0.0001). Plasma cells did characteristically show a low Ki-67 proliferation index in 14/15 MGUS patients (mean 0.05%, range 0-0.2%) and a higher index in 25 analysed MM patients (mean 2.31%, range 1-7%, P < 0.03). These data indicate that MDR-1 expression together with absence of CD56 expression and a low proliferation index can be used to separate MGUS from MM.
authors.affiliation: Erasmus University, Department of Haematology, Rotterdam, The Netherlands.
authors.forename: P
authors.initials: P
authors.lastname: Sonneveld
authors.forename: B G
authors.initials: BG
authors.lastname: Durie
authors.forename: H M
authors.initials: HM
authors.lastname: Lokhorst
authors.forename: Y
authors.initials: Y
authors.lastname: Frutiger
authors.forename: M
authors.initials: M
authors.lastname: Schoester
authors.forename: E E
authors.initials: EE
authors.lastname: Vela
mesh_terms: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D015703:Antigens, CD / Q000032:analysis*; D000945:Antigens, Differentiation, T-Lymphocyte / Q000032:analysis*; D001853:Bone Marrow / Q000737:chemistry; D019002:CD56 Antigen; D003937:Diagnosis, Differential; D004351:Drug Resistance; D005260:Female; D006801:Humans; D007694:Killer Cells, Natural / Q000276:immunology; D008297:Male; D008562:Membrane Glycoproteins / Q000032:analysis*; D008875:Middle Aged; D008940:Mitotic Index; D008998:Monoclonal Gammopathy of Undetermined Significance / Q000175:diagnosis*; D009101:Multiple Myeloma / Q000175:diagnosis*
chemical_list: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D015703:Antigens, CD; D000945:Antigens, Differentiation, T-Lymphocyte; D019002:CD56 Antigen; D008562:Membrane Glycoproteins