Effects of oxidative stress on red blood cell rheology in sickle cell patients

Sickle cell anaemia (SS) and sickle cell-haemoglobin C disease (SC) patients exhibit severe red blood cell (RBC) rheological alterations involved in the development of several complications. The contribution of oxidative stress in these haemorheological abnormalities is still unknown. We compared RBC reactive oxygen species (ROS) and glutathione (GSH) content, and the haemorheological profile of SS (n = 11), SC (n = 11) and healthy subjects (n = 12) at baseline and after in-vitro treatment with t-butyl hydroperoxide (TBHP). We showed: (i) higher RBC ROS content in SS and SC patients, with the highest level observed in SS patients; (ii) lower RBC GSH content in sickle syndrome patients, especially in SS patients; (iii) TBHP increased RBC ROS production and decreased RBC GSH content in all groups; (iv) TBHP decreased RBC aggregation and increased the strength of RBC aggregates in all groups but the increase in RBC aggregates strength was greater in sickle cell patients; (v) TBHP decreased RBC deformability in the three groups but with a higher magnitude in sickle cell patients. These data suggest that RBCs from sickle cell patients have an exaggerated response to oxidative stress, which is accompanied by a profound abnormal haemorheological profile, with greater alterations in SS than in SC patients.