Hepatic iron stores and plasma ferritin concentration in patients with sickle cell anemia and thalassemia major

Abstract

To examine the relationship between hepatic iron stores and plasma ferritin concentration in individuals treated with red cell transfusion and iron chelation therapy, 37 patients with sickle cell anemia and 74 patients with thalassemia major were studied. In each patient, hepatic iron stores were measured by an independently validated noninvasive magnetic method, and plasma ferritin was determined by immunoassay. The correlation between hepatic iron and plasma ferritin was significant both in patients with sickle cell anemia (R = 0.75, P < 0.0001) and in those with thalassemia major (R = 0.76, P < 0.0001). Regression analysis showed no significant difference between the two groups in the linear relationships between hepatic iron stores and plasma ferritin. Considering all 111 transfused patients as a group, the coefficient of correlation between hepatic iron stores and plasma ferritin was highly significant (R = 0.76, P < 0.0001). Regression analysis found that variation in body iron stores, as assessed by magnetic determinations of hepatic iron, accounted for only approximately 57% of the variation in plasma ferritin, suggesting that the remainder was the result of other factors, such as hemolysis, ineffective erythropoiesis, ascorbate deficiency, inflammation, and liver disease. The 95% prediction intervals for hepatic iron concentration, given the plasma ferritin, were so broad as to make a single determination of plasma ferritin an unreliable predictor of body iron stores. Variability resulting from factors other than iron status limits the clinical usefulness of the plasma ferritin concentration as a predictor of body iron stores.

Concepts and goals in the management of transfusional iron overload

“…Consequently, there is no evidence of iron overload in sickle cell anemia, unless blood transfusions are given repeatedly [15,16]. About 10-20% of patients with SCD receive repeated transfusions and serum ferritin values increase proportionately with units of blood transfused [17] and liver iron concentrations [18]-provided ferritin samples are taken a sufficient interval after a vaso-occlusive crisis, when values can be greatly elevated [17]. Patients with SCD and transfusion-dependent thalassemia, if transfused at the same rate, show a similar rate of liver iron loading as well as the same risk of liver fibrosis at certain iron levels [19,20].…”

Transfusional iron overload in children with sickle cell anemia on chronic transfusion therapy for secondary stroke prevention

“…1), underscoring that other factors including inflammation affect serum ferritin levels. Prior reports have shown conflicting results regarding the correlation of ferritin and LIC in transfused SCA patients [15][16][17]. A recent report showed ferritin levels <1,500 ng/mL correlated with an LIC <10 mg/g dw, while serum ferritin levels above 3,000 ng/mL usually predicted LIC >10 mg/g dw [18].…”

Deferiprone versus Deferoxamine in Sickle Cell Disease: Results from a 5-year long-term Italian multi-center randomized clinical trial

“…The limit of the study could be that serum ferritin levels in patients with SCD have shown varying degrees of correlation with LIC, which is considered a more direct measure of iron overload, especially in pediatrics patients [30,31].However, the design of the study as randomized clinical trial, the effectiveness of treatment evaluated at repeated measurement on the same patient over time of serum ferritin levels and the inclusion in the trial of a large cohort of adult patients, may surely have balance effect on this bias.…”