Oxidative stress and antioxidant status in beta-thalassemia heterozygotes.
BACKGROUND
Several studies have evaluated the oxidant and antioxidant status of thalassemia patients but most focused mainly on the severe and intermediate states of the disease. Moreover, the oxidative status has not been evaluated for the different beta-thalassemia mutations.


OBJECTIVE
To evaluate lipid peroxidation and Trolox equivalent antioxidant capacity in relation to serum iron and ferritin in beta thalassemia resulting from two different mutations (CD39 and IVS-I-110) compared to individuals without beta-thalassemia.


METHODS
One hundred and thirty subjects were studied, including 49 who were heterozygous for beta-thalassemia and 81 controls. Blood samples were subjected to screening tests for hemoglobin. Allele-specific polymerase chain reaction was used to confirm mutations for beta-thalassemia, an analysis of thiobarbituric acid reactive species was used to determine lipid peroxidation, and Trolox equivalent antioxidant capacity evaluations were performed. The heterozygous beta-thalassemia group was also evaluated for serum iron and ferritin status.


RESULTS
Thiobarbituric acid reactive species (486.24 ± 119.64 ng/mL) and Trolox equivalent antioxidant capacity values (2.23 ± 0.11 mM/L) were higher in beta-thalassemia heterozygotes compared to controls (260.86 ± 92.40 ng/mL and 2.12 ± 0.10 mM/L, respectively; p-value < 0.01). Increased thiobarbituric acid reactive species values were observed in subjects with the CD39 mutation compared with those with the IVS-I-110 mutation (529.94 ± 115.60 ng/mL and 453.39 ± 121.10 ng/mL, respectively; p-value = 0.04). However, average Trolox equivalent antioxidant capacity values were similar for both mutations (2.20 ± 0.08 mM/L and 2.23 ± 0.12 mM/L, respectively; p-value = 0.39). There was no influence of serum iron and ferritin levels on thiobarbituric acid reactive species and Trolox equivalent antioxidant capacity values.


CONCLUSIONS
This study shows an increase of oxidative stress and antioxidant capacity in beta-thalassemia heterozygotes, mainly in carriers of the CD39 mutation.
Universidade Estadual de Goiás - UEG, Anápolis, GO, Brazil.
Luciana de Souza
Lde S
Ondei
Universidade Estadual Paulista - UNESP, São José do Rio Preto, SP, Brazil.
Isabeth da Fonseca
Ida F
Estevão
Universidade Estadual Paulista - UNESP, São José do Rio Preto, SP, Brazil.
Marina Ibelli Pereira
MI
Rocha
Universidade Federal do Pará - UFPA, Belém, PA, Brazil.
Sandro
S
Percário
Fundação Faculdade Regional de Medicina de São José do Rio Preto - FUNFARME, São José do Rio Preto, SP, Brazil.
Dorotéia Rossi Silva
DR
Souza
Fundação Faculdade Regional de Medicina de São José do Rio Preto - FUNFARME, São José do Rio Preto, SP, Brazil.
Marcela Augusta de Souza
MA
Pinhel
Universidade Estadual Paulista - UNESP, São José do Rio Preto, SP, Brazil.
Claudia Regina
CR
Bonini-Domingos
Beta-globins; Beta-thalassemia; Lipid peroxidation; Mutation; Oxidative stress; Thiobarbituric acid reactive substances