Reduced peripheral blood superoxide dismutase 2 expression in sickle cell disease

Sickle cell disease (SCD), a hereditary form of chronic hemolytic anemia, is characterized by acute vascular occlusion and chronic complications as pulmonary hypertension (PH), a hallmark of higher mortality. This study aimed to determine peripheral blood expression of superoxide dismutase 2 (SOD2), a major mitochondrial antioxidant enzyme in SCD patients on the mRNA level and compared it with SOD2 expression in healthy individuals. It also aimed to detect possible differences in SOD2 expression among patients with/without specific SCD complications and to detect possible correlations with patient laboratory parameters. SOD2 mRNA levels were significantly lower in SCD patients in comparison with controls and correlated with red blood cell count, reticulocyte count, platelet count, C-reactive protein, ferritin, and brain natriuretic peptide values. SCD patients with echocardiographic indications of PH featured significantly reduced SOD2 expression in comparison with patients without such indications. Consequently, SOD2 expression emerges as a potential biomarker of PH in SCD being a link among hemolysis, inflammation, iron overload, oxidative stress, and SCD cardiopathy.