Non-transferrin bound labile plasma iron and iron overload in Sickle Cell Disease: a comparative study between Sickle Cell Disease and β thalassemic patients

Background: Blood transfusions are the standard of care in beta thalassemia and transfusions are also indicated in sickle cell disease (SCD) patients with hypersplenism, recurrent vaso-occlusive crises and for stroke prevention. Iron overload caused by blood transfusions in thalassemia and in SCD may affect morbidity and mortality. Recent studies of iron overload in SCD suggest that the biologic features of SCD and the chronic inflammatory state may protect SCD patients from iron damage. Designs and methods: In view of the controversy regarding the effect of iron overload in patients with SCD we studied the iron status, including non-transferrin bound iron (NTBI) and labile plasma iron (LPI) levels in a cohort of 36 SCD patients and compare the results with 43 thalassemia patients. Results: Our results indicate that none of the SCD patients had clinical symptoms of iron overload. Only two SCD patients had NTBI values in the gray zone (0.4 units) and none had positive values. By contrast, 14 patients with thalassemia major and three with thalassemia intermedia had NTBI values above 0.6, level that are in the positive pathological range. Similarly, four thalassemia patients, but only one SCD patient had positive LPI levels. Conclusions: The parameters of iron status in SCD patients, even after frequent transfusions are different when compared to patients with thalassemia. The low NTBI and LPI levels found in patients with SCD are in keeping with the absence of clinical signs of iron overload in this disease.