Vives Corrons J L, Miguel-García A, Pujades M A, Miguel-Sosa A, Cambiazzo S, Linares M, Dibarrart M T, Calvo M A
Haematology Laboratory Department, Hospital Clínic i Provincial, University of Barcelona, Spain.
Eur J Haematol. 1995 Nov;55(5):327-31. doi: 10.1111/j.1600-0609.1995.tb00705.x.
Oxidative damage to erythrocytes in thalassaemia has been related to generation of free radicals by an excess of denaturated alpha- or beta-globin chains, intracellular iron overload and low concentration of normal haemoglobin (HGB). Two good indicators of such oxidative damage are the high red blood cell (RBC) malonyldialdehyde (MDA) production detected following exogenous oxidant stress and the decrease of pyrimidine 5'-nucleotidase (P5N), the most sensitive enzyme to SH-group damage in vivo. Conflicting data, however, have so far accumulated in the literature concerning differences in oxidative damage between the different forms of thalassaemia and iron deficiency anaemia (IDA). In the present study, oxidative susceptibility, as defined by the production of MDA in vitro and antioxidant capacity, as measured by the activity of RBC glutathione peroxidase (GPx), superoxide dismutase (SOD) and by reduced glutathione (GSH), have been studied in microcytic RBCs from patients with beta-thalassaemia trait, Spanish (delta beta) zero-thalassaemia heterozygotes (delta beta-thalassaemia trait) and iron deficiency anaemia (IDA). The results are consistent with the existence of significant differences in the severity and pattern of oxidative stress susceptibility between beta-thalassaemia trait (increased MDA production and higher SOD and GPx activities) and the other two forms of microcytosis (delta beta thalassaemia trait and IDA). Furthermore, the finding of normal P5' N activity in delta beta thalassaemia trait, gives further support to the less intense peroxidative environment of RBCs in this form of thalassaemia when compared to beta-thalassaemia trait, characterized by acquired RBC P5' N deficiency due to oxidative damage.
地中海贫血中红细胞的氧化损伤与过量变性的α或β珠蛋白链产生自由基、细胞内铁过载以及正常血红蛋白（HGB）浓度降低有关。这种氧化损伤的两个良好指标是外源性氧化应激后检测到的高红细胞（RBC）丙二醛（MDA）生成以及嘧啶5'-核苷酸酶（P5N）的降低，P5N是体内对SH基团损伤最敏感的酶。然而，关于不同形式的地中海贫血和缺铁性贫血（IDA）之间氧化损伤差异的相互矛盾的数据，目前已在文献中积累。在本研究中，对β地中海贫血特征患者、西班牙（δβ）零地中海贫血杂合子（δβ地中海贫血特征）和缺铁性贫血（IDA）患者的小细胞红细胞进行了研究，通过体外MDA生成定义氧化易感性，通过红细胞谷胱甘肽过氧化物酶（GPx）、超氧化物歧化酶（SOD）活性以及还原型谷胱甘肽（GSH）来测量抗氧化能力。结果表明，β地中海贫血特征（MDA生成增加以及SOD和GPx活性较高）与其他两种小细胞性贫血形式（δβ地中海贫血特征和IDA）之间在氧化应激易感性的严重程度和模式上存在显著差异。此外，δβ地中海贫血特征中P5'N活性正常这一发现，进一步支持了与β地中海贫血特征相比，这种地中海贫血形式的红细胞过氧化环境较弱的观点，β地中海贫血特征以因氧化损伤导致的获得性红细胞P5'N缺乏为特征。
