Compositional and Structural Alterations of Arterial Glycosaminoglycans Associated with the Complications Brought About by Thalassemia Major

Abstract

A biochemical analysis of glycosaminoglycans was performed in arteries of a fifteen-year-old white male who died of β thalassemia major. The patient presented the severe clinical complications resulting from hemochromatosis, which was evidenced at autopsy and by histologic examination. The arteries under study comprised the thoracic and abdominal aortas and the iliac and pulmonary arteries, which were compared with the same arteries from normal individuals. Data on total glycosaminoglycan and total collagen, including the determination of the relative contents of the different glycosaminoglycans, suggest an as yet undescribed fibrotic process in the thalassemic arteries. Also altered were the proportions of the disaccharides making up chondroitin sulfate and heparan sulfate. A reduction in the molecular weight of arterial heparan sulfate, presumably with free radical involvement, was also detected. All these changes in the extracellular matrix may be ascribed to the presence of large amounts of iron in the tissue, and as such they should be expected in other disorders with chronic iron overload.