title: P-glycoprotein and glutathione S-transferase pi in childhood acute lymphoblastic leukaemia.
abstract: Blast cells obtained from 104 children with untreated acute lymphoblastic leukaemia were analysed for the expression of P-glycoprotein (P-170) and glutathione S-transfer pi (GST-pi) using immunohistochemistry. Expression of P-170 was detected in 36 of 104 patients (35%) and increased GST-pi was seen in 52 patients (50%). Coexpression of both resistance proteins was observed in 22 leukaemias (21%), whereas no evidence of the resistance markers was found in 38 cases (37%). In patients with P-170-positive leukaemic cells, a significantly lower probability of remaining in first continuous complete remission (CCR) was observed when compared with patients with P-170-negative tumours (P < 0.05). However, only a trend for a more frequent expression of P-170 was found in the leukaemic cells of patients who experienced relapses (P = 0.099). Overexpression of GST-pi was correlated with a higher relapse rate (P = 0.001) and a lower probability of remaining in first CCR (P = 0.01). Expression of P-170 and GST-pi was independent of sex, FAB type, immunological subtype and initial blast cell count. The multivariate analysis indicated that only the expression of P-170 is an unfavourable prognostic factor for children with acute lymphoblastic leukaemia in addition to the prognostic clinical factors.
authors.affiliation: University of Jena, Children's Hospital, Germany.
authors.forename: A
authors.initials: A
authors.lastname: Sauerbrey
authors.forename: F
authors.initials: F
authors.lastname: Zintl
authors.forename: M
authors.initials: M
authors.lastname: Volm
mesh_terms: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1 / Q000378:metabolism*; D002648:Child; D002675:Child, Preschool; D005260:Female; D005982:Glutathione Transferase / Q000378:metabolism*; D006801:Humans; D007223:Infant; D008297:Male; D054198:Precursor Cell Lymphoblastic Leukemia-Lymphoma / Q000175:diagnosis / Q000201:enzymology*; D016019:Survival Analysis
chemical_list: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D005982:Glutathione Transferase