Iron status in sickle cell disorders

Abstract

Background: There is a general view that patients with sickle cell disease (SCD) reveal iron overload and that iron deficiency anemia is uncommon in them because of the availability of an adequate iron source from increased red cell turnover and blood transfusions. However, there are reports of iron deficiency in a proportion of these patients, which can often be missed because they exhibit already anemic condition. Objective: To evaluate the iron status and to determine the incidence of iron deficiency in sickle cell disorders including subjects with SCD, sickle cell trait (SCT), and compound heterozygosity. Materials and Methods: A total of 155 subjects were included in study; 138 of these showed homozygous sickle cell anemia (SS) and 17 sickle cell trait (AS). Presence of HbS was detected by solubility test, followed by hemoglobin phenotype determination by automated HPLC. The measurement of serum iron and total iron-binding capacity was done by ferrozine method, serum ferritin by radioimmunoassay, and zinc protoporphyrin (ZPP) by using ProtoFluor-Z Hematofluorimeter, while hematological parameters were determined using a Sysmex Kx21 autoanalyzer. Result: Of the 155 patients studied, 7 (4.5%) showed iron deficiency and 33 (21.3%) showed iron overload. Iron and serum ferritin values in transfused patients were significantly higher than in nontransfused patients. The mean reticulocyte count was significantly lower in iron deficient group than that in iron sufficient group. The ZPP values were elevated in all iron deficient and the 39 of 148 iron sufficient/overloaded subjects; however, ZPP values were much higher in the iron deficiency group. Conclusion: A state of iron deficiency may be present in SCD and SCT patients. Therefore, we recommend that patients with SCD and SCT should be screened for iron deficiency by conventional laboratory tests.