Oxidative stress in red blood cells, platelets and polymorphonuclear leukocytes from patients with myelodysplastic...

Low-risk myelodysplastic syndrome (MDS) is characterized by cytopenia, mainly anemia, because of ineffective hematopoiesis. Some of the patients with ineffective erythropoiesis, with or without ring sideroblasts in their bone marrow, develop severe anemia requiring frequent blood transfusions and consequently develop iron overload. Excess free iron in cells catalyses the generation of reactive oxygen species (ROS) that cause cell and tissue damage. Using flow cytometry techniques, we compared the oxidative status of red blood cells (RBC), platelets and neutrophils in 14 MDS patients with those of normal donors. The results show that ROS were higher while reduced glutathione (GSH) was lower in their RBC and platelets compared with normal cells. In neutrophils, no difference was found in ROS, while the GSH levels were lower. A correlation (r = 0.6) was found between serum ferritin levels of the patients and the ROS in their RBC and platelets. The oxidative stress was ameliorated by a short incubation with the iron-chelators, the deferrioxamine and deferiprone or with antioxidants such as N-acetylcysteine, suggesting that MDS patients might benefit from treatment with iron-chelators and antioxidants.