Monday, May 29, 2017

Treatment Options for Thalassemia Major



Before chronic transfusions are initiated, the diagnosis of Beta-thalassemia should be confirmed and the parents counseled about this lifelong therapy. Initiating transfusion and chelation therapy can be difficult for parents to face early in their child’s life.

If there is the possibility of a bone marrow transplant, the blood should be negative for cytomegalovirus and irradiated.

Blood Transfusion therapy:
Transfusion therapy promotes general health and well-being and avoids the consequences of ineffective erythropoiesis. A transfusion program generally requires monthly transfusions, with the pretransfusion hemoglobin level >9.5 and <10.5 g/dL. In patients with cardiac disease, higher pretransfusion hemoglobin levels may be beneficial. Some blood centers have donor programs that pair donors and recipients, decreasing the exposure to multiple red cell antigens.

Transfusional hemosiderosis causes many of the complications of thalassemia major. Accurate assessment of excessive iron stores is essential to optimal therapy. The serum ferritin level is useful in assessing iron balance trends, but does not accurately predict quantitative iron stores. Undertreatment or overtreatment of presumed excessive iron stores can occur when a patient is managed based on the serum ferritin level alone.

Iron Chelation:Transfusional hemosiderosis can be prevented by the use of deferoxamine (Desferal). Deferoxamine chelates iron and some other divalent cations, allowing their excretion in urine and stool. Deferoxamine is given subcutaneously over 10–12 hr, 5–6 days a week. Side effects include ototoxicity with high-frequency hearing loss, retinal changes, and bone dysplasia with truncal shortening. The number of hours deferoxamine is used daily is more important than the daily dose.

Deferiprone is a new iron chelator approved by the U.S. Food and Drug Administration for children >2 yr of age. Deferiprone may not be as effective as deferoxamine in total body iron chelation, but may be more effective in removing cardiac iron. Side effects include neutropenia, and weekly blood counts are needed.

Bone marrow transplantation:Bone marrow transplantation has cured >1,000 patients who have thalassemia major. Most success has been in children younger than 15 yr of age without excessive iron stores and hepatomegaly who have HLA-matched siblings. All children who have an HLA-matched sibling should be offered the option of bone marrow transplantation.

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