Oxidative stress and antioxidant capacity in hereditary elliptocytosis and hereditary pyropoikilocytosis

Hereditary elliptocytosis (HE) and hereditary pyropoikilocytosis (HPP) are red blood cell (RBC) membrane disorders caused by defects in spectrin interactions, leading to variable degrees of haemolysis. This study aimed to compare RBC fragility, oxidative stress and antioxidant capacity among individuals with HE, HPP and healthy controls. Blood samples from 15 subjects (n = 5 per group) were analysed. Chemical-induced haemolysis assays revealed significantly increased haemolysis in HPP RBCs, whereas haemolysis did not differ between HE and healthy controls. Intracellular reactive oxygen species (ROS) were highest in HPP RBCs under basal and 0.5 mM H₂O₂-induced conditions. Lipid peroxidation was increased in HPP RBC ghosts under basal conditions and was significantly elevated in plasma compared with both normal and HE groups. Antioxidant enzyme activities (superoxide dismutase [SOD] and glutathione peroxidase [GPx]) were largely comparable among groups, except for increased RBC SOD activity in HPP compared with normal controls. These findings indicate that HPP is characterized by marked membrane instability, elevated oxidative stress and increased lipid peroxidation, while antioxidant capacity remains relatively preserved. Collectively, these abnormalities are likely to contribute to the severe haemolytic phenotype observed in HPP compared with HE and healthy individuals.