Transfusion management of hemoglobinopathies Volume 10, issue 6, Novembre-Décembre 2004

Service de pédiatrie générale, hôpital Necker Enfants Malades, 149 rue de Sèvres, 75015 Paris

Blood transfusion plays a key role in the treatment of patients affected with hemoglobinopathies. Inadequate or insufficient blood supplies are largely responsible for the morbidity and the mortality of major thalassemic and sickle cell syndromes. Transfusional regimen in thalassemia major patients aim to maintain hemoglobin levels above 9-10 g/dL, which is usually provided by packed red cells supplies around 150-200 mL/kg/yr. These transfusional programmes have improved dramatically the prognosis of thalassemia major. Transfusional needs are greatly variable in patients affected with sickle cell disease (SCD). Transfusion has two indications, 1) to correct an acute anemia, 2) to decrease hemoglobin S percentage under a given threshold. The latter indications have been largely modified in the recent years, in particular after evidence that cerebro-vascular accidents in children could be early detected using transcranial doppler, and prevented by regular transfusion in children with high velocity in cerebral arteries. On the other hand, hydroxyurea and bone marrow transplantation are now discussed for treatment of severe forms of sickle cell disease, as an alternative to regular transfusions.Main complication of chronic transfusion is iron overload, which is now the most important prognostic factor in thalassemia major patients. Deferoxamine is the most used chelator, and needs sub-cutaneous infusions. The place for new oral chelators is still debated. Transfusion-related infections are no more major threats in developed countries. Red cells alloimmunization has been reported to have an increased frequency in SCD patients, firstly because some rare RH phenotypes are encountered in the black population, secondly because of different distributions of blood group antigens between donors and recipients. Lastly, implantable venous access devices are required in some patients, but an increased frequency of infectious complications seems to occur in SCD patients.