Selenium inadequacy is not associated with oxidative stress in child and adolescent acute lymphocytic leukemia survivors.
OBJECTIVE
Acute lymphocytic leukemia (ALL) and its subsequent treatment may provoke increased oxidative stress. The aim of this study was to investigate the antioxidant status of children and adolescents who had received ALL therapy, and to test the hypothesis that selenium (Se) inadequacy is correlated with reduced defenses against oxidative stress in this population.


METHODS
This case-control study involved 24 patients between ages 5 and 13 y who had been treated successfully for ALL (ALL group) and 60 children of similar age and socioeconomic background with no clinical history of leukemia (control group). Dietary intake of Se was evaluated by the 24-h recall method, and the concentrations of Se in plasma, erythrocytes, and urine determined. Antioxidant status was assessed by analysis of the oxidative stress markers, namely, superoxide dismutase (SOD), glutathione peroxidase (GPx), malondialdehyde (MDA), α-tocopherol, and 8-oxo-deoxyguanosine (8-oxo-dG).


RESULTS
There were no between-group differences with respect to plasma (P = 0.122), erythrocyte (P = 0.202), urinary (P = 0.608), or dietary (P = 0.757) levels of Se. GPx activity was significantly (P < 0.001) reduced in the ALL group compared with the control group, whereas SOD activity and MDA concentrations were similar. The concentrations of α-tocopherol and 8-oxo-dG were significantly increased in the ALL group compared with the control group (P < 0.001 and P = 0.031, respectively).


CONCLUSIONS
All participants were Se inadequate, but such inadequacy was not correlated with reduced defenses against oxidative stress. However, individuals of the ALL group were with increased oxidative stress compared with the control group, possibly due to previous disease and to intensive polychemotherapy.
Departamento de Alimentos e Nutrição Experimental, Faculdade de Ciências Farmacêuticas, Universidade de São Paulo, São Paulo, Brazil. Electronic address: Kaluce@usp.br.
Kaluce Gonçalves de Sousa
KG
Almondes
Departamento de Análises Clínicas e Toxicológicas, Faculdade de Ciências Farmacêuticas, Universidade de São Paulo, São Paulo, Brazil.
Tiago Franco
TF
de Oliveira
Divisão de Endocrinologia Pediátrica, Departamento de Pediatria, Universidade Federal de São Paulo, São Paulo, Brazil.
Adriana Aparecida
AA
Siviero-Miachon
Instituto de Oncologia Pediátrica, Universidade Federal de São Paulo, São Paulo, Brazil.
Maria Lúcia de Martino
ML
Lee
Departamento de Nutrição, Escola de Saúde Pública, Universidade de São Paulo, São Paulo, Brazil.
Patrícia Helen de Carvalho
PH
Rondó
Departamento de Análises Clínicas e Toxicológicas, Faculdade de Ciências Farmacêuticas, Universidade de São Paulo, São Paulo, Brazil.
Ana Paula de Melo
AP
Loureiro
Divisão de Endocrinologia Pediátrica, Departamento de Pediatria, Universidade Federal de São Paulo, São Paulo, Brazil.
Angela Maria
AM
Spinola-Castro
Departamento de Alimentos e Nutrição Experimental, Faculdade de Ciências Farmacêuticas, Universidade de São Paulo, São Paulo, Brazil.
Silvia Maria Franciscato
SM
Cozzolino
D000293:Adolescent; D000975:Antioxidants / Q000378:metabolism*; D015415:Biomarkers / Q000378:metabolism; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D003677:Deficiency Diseases / Q000150:complications* / Q000378:metabolism; D003849:Deoxyguanosine / Q000097:blood; D004912:Erythrocytes / Q000378:metabolism; D005260:Female; D005979:Glutathione Peroxidase / Q000378:metabolism; D006801:Humans; D015227:Lipid Peroxidation; D008297:Male; D008315:Malondialdehyde / Q000097:blood; D018384:Oxidative Stress; D054198:Precursor Cell Lymphoblastic Leukemia-Lymphoma / Q000150:complications / Q000378:metabolism*; D012643:Selenium / Q000097:blood / Q000172:deficiency* / Q000652:urine; D013482:Superoxide Dismutase / Q000378:metabolism; D017741:Survivors; D024502:alpha-Tocopherol / Q000097:blood
D000975:Antioxidants; D015415:Biomarkers; D008315:Malondialdehyde; D005979:Glutathione Peroxidase; D013482:Superoxide Dismutase; D003849:Deoxyguanosine; D024502:alpha-Tocopherol; D012643:Selenium
Acute lymphoblastic leukemia; Antioxidants; Chemotherapy; DNA damage; Oxidative stress; Selenium