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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.

Cardiovascular involvement is a leading cause of mortality and morbidity in patients with inherited hemoglobinopathies, but it has not been adequately assessed in sickle beta-thalassemia. We evaluated 115 sickle beta-thalassemia patients, aged 34 +/- 14 years, along with 50 healthy controls, by resting echocardiography. Patients with systolic left ventricular (LV) dysfunction or severe pulmonary hypertension (PHT) also underwent left and right cardiac catheterization and cardiac magnetic resonance imaging (CMR). Left and right chamber dimensions, LV mass, and cardiac index were significantly higher in patients compared to controls (p < 0.001 in most cases). Three patients (2.9%) had reduced LV ejection fraction (<55%); mean LV ejection fraction was significantly lower in patients (p < 0.001). Left and right ventricular systolic tissue Doppler indices and LV diastolic tissue Doppler indices were also impaired in patients. All three patients with systolic LV dysfunction had normal coronary arteries and mild myocardial iron load (CMR T2* values, 18-25 ms). Systolic pulmonary artery pressure was significantly higher in patients compared to controls (p = 0.002); PHT was present in 28 patients (27%), while severe PHT in three (2.9%). In three patients with severe PHT, only one had impaired LV ejection fraction and increased pulmonary wedge pressure. Overall, three patients (2.9%) had a history of heart failure, two with systolic LV dysfunction, and one with severe PHT. Cardiac involvement in sickle beta-thalassemia concerns biventricular dilatation and dysfunction along with PHT, leading to congestive heart failure.

Splenomegaly is common in beta-thalassemia, bearing some particular hemodynamic features, while splenectomy is an established therapeutic intervention in these patients. Their effects, however, on systemic hemodynamics and thalassemia heart disease have not yet been assessed. The study included 32 consecutive patients, 13 with thalassemia major (TM) and 19 with thalassemia intermedia (TI), aged 23.4+/-4.2 years, requiring splenectomy. Assessment was performed before and 6 months after splenectomy and included hematological profile and resting echocardiography; total blood volume was also measured in 10 of 32 cases. Preoperative echocardiographic data were compared with those of 34 controls. Preoperative left ventricular diameters and mass, cardiac index, and systolic pulmonary artery pressure were all significantly higher in patients compared to controls (p<0.001), but did not differ significantly between TM and TI patients. Postoperatively, the mean hemoglobin level increased from 8.1+/-0.6 to 9.1+/-0.4 g/dl (p<0.001), total blood volume index declined from 2847+/-332 to 2310+/-276 ml/m(2) (p<0.001), blood transfusions were discontinued in 80% of TI patients and mean 6-monthly transfusion requirements in TM patients were reduced from 28+/-5 to 22+/-4 units (p<0.001). However, cardiac parameters were not significantly modified. It seems that left ventricular remodeling, high output state, and increased pulmonary artery pressure characterize both TM and TI patients who require splenectomy. Although these abnormalities remain unchanged after splenectomy, the removal of the spleen may contribute to the prevention of further cardiac damage by ameliorating the patients' hematological status and reducing their transfusion needs.