Thalassemia intermedia is associated with a proatherogenic biochemical phenotype

Unlike beta thalassemia major (β-TM) in which cardiac siderosis represents the leading cause of mortality and morbidity, in beta thalassemia intermedia (β-TI), pulmonary hypertension (PHT) and thrombosis seems to be the major cardiovascular complications. However, the mechanism underlying these complications in β-TI is still unclear. Endothelial dysfunction, the key early event in atherogenesis, is now emerging as an important cardiovascular risk determiner in β-TI patients. Among the factors known to affect endothelial function, iron and cholesterol merit particular consideration in β-TI patients. Therefore, with the aim to extend our knowledge on the mechanisms connecting atherosclerosis to β-TI, in this study, we compared lipid and iron metabolism in serum and in peripheral blood mononuclear cells (PBMCs) from β-TI and β-TM patients and controls.

In this study the iron status and the lipid profile in serum and in peripheral blood mononuclear cells (PBMCs) of 22 adult β-TI patients were examined, and compared with 70 adult β-TM, and 50 age-matched controls. Despite the great variability, levels of serum iron and transferrin saturation were significantly higher in β-TI compared to both controls and β-TM. By contrast, transferrin and hepcidin levels were lower in β-TI patients. Changes in serum indicators in β-TI patients were associated with altered expressions in PBMCs of hepcidin and IL-1α, involved in some way in the regulation of iron homeostasis. In addition β-TI exhibited a reduction of total and high density lipoprotein cholesterol in serum and of neutral cholesterol ester hydrolase in PBMCs, and an increase of cytoplasmic neutral lipids and mRNA levels of acetyl-coenzymeA:cholesterol acyltransferase.

Taken together, these findings provide experimental support for the idea that β-TI patients exhibit a proatherogenic biochemical phenotype which may contribute to enhance cardiovascular risk in these subjects.