Clinical manifestations and therapy of transfusional haemosiderosis.

Long-term blood transfusions lead to the accumulation of iron that in the absence of chelation therapy causes complications such as liver cirrhosis, growth failure, hypogonadism, hypothyroidism, hypoparathyroidism, diabetes and myocardiopathy. The last still represents the most frequent cause of death in haemosiderotic transfusion-dependent patients. At the moment the only chelator widely used is desferrioxamine (DFX). The drug works best when administered as a continuous infusion, mainly by the subcutaneous route. To patients with severe iron overload, impending organ failure, or poor compliance to chelation, DFX can be administered intravenously, through an externalized central catheter or, preferably, a subcutaneous port. Several studies have shown the effectiveness of DFX in reducing the iron burden, thus preventing the complications, once considered inevitable, of iron overload, and even in reverting some, but not all, of the iron-induced dysfunctions. Practical and psychological support are necessary to ensure satisfactory compliance with a therapy that is cumbersome and difficult. Toxic effects of DFX such as growth failure, hearing impairment and bone abnormalities seem to occur mainly in patients who have received high doses of DFX despite a low iron burden. Visual loss and renal and pulmonary toxicities, on the contrary, seem to be more directly related to high DFX peak doses administered irrespective of the patient's amount of iron overload. After bone marrow transplantation, phlebotomy or erythrocytoapheresis might be necessary to reduce further the iron accumulated during years of transfusions.