title: A possible role for oxidation stress in lymphoid leukaemias and therapeutic failure.
abstract: The aim of this study was to evaluate the role of oxidative stress in the pathobiology of lymphoid leukaemias and its involvement in leukaemic relapse. For this purpose the generation of peroxides by mononuclear cells, the erythrocyte activity of superoxide-dismutase (SOD) and glutathione peroxidase (GL-PX), and the plasma levels of reduced glutathione (GSH) and vitamin E (VIT E) were determined in 52 patients with two different types of lymphoid leukaemias, chronic lymphocytic leukaemia (CLL) and acute lymphoblastic leukaemia (ALL), 36 prior to chemotherapy and 16 treated patients. A decrease in SOD and GL-PX activities was observed in ALL patients prior to therapy, while a decrease in GSH and VIT E plasma levels was observed in untreated CLL, as compared to age-matched controls. An increase in peroxides formation occurred in both types of leukaemia, as compared to age-matched controls. There are significant differences for GSH, VIT E and peroxides generation between the different types of leukaemias. In relapsed ALL patients a decrease in peroxides generation was observed which may be due to the increase of the non-enzymatic defences GSH and VIT E. These data suggest the involvement of oxidative stress in acute and chronic lymphoid leukaemias and leukaemic relapse.
authors.affiliation: Applied Molecular Biology/Biochemistry Institute and University Clinic of Haematology, Faculty of Medicine, University of Coimbra, Coimbra, Portugal. absarmento@fmed.uc.pt
authors.forename: Ana Bela
authors.initials: AB
authors.lastname: Sarmento-Ribeiro
authors.forename: Maria T
authors.initials: MT
authors.lastname: Proença
authors.forename: Isabel
authors.initials: I
authors.lastname: Sousa
authors.forename: Amélia
authors.initials: A
authors.lastname: Pereira
authors.forename: Fátima
authors.initials: F
authors.lastname: Guedes
authors.forename: Adriana
authors.initials: A
authors.lastname: Teixeira
authors.forename: Catarina R
authors.initials: CR
authors.lastname: Oliveira
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use; D016022:Case-Control Studies; D019008:Drug Resistance, Neoplasm / Q000502:physiology; D006801:Humans; D007945:Leukemia, Lymphoid / Q000175:diagnosis* / Q000188:drug therapy / Q000209:etiology* / Q000378:metabolism; D008875:Middle Aged; D010084:Oxidation-Reduction; D018384:Oxidative Stress / Q000187:drug effects / Q000502:physiology*; D011379:Prognosis; D012008:Recurrence; D017211:Treatment Failure; D055815:Young Adult