Serum ferritin underestimates liver iron concentration in transfusion independent thalassemia patients as compared to regularly transfused thalassemia and sickle cell patients

Serum ferritin (SF) and liver iron concentration (LIC), as measured by SQUID biosusceptometry, were assessed in a convenience sample of transfusion independent thalassemia patients (nTx-Thal, n=26), regularly transfused thalassemia (Tx-Thal, n=89), or sickle cell patients (SCD, n=45) to investigate the severity of iron overload and the relationship between SF and LIC in nTx-Thal compared to SCD and Tx-Thal. SF correlated with LIC (RS=0.53, P<0.001), but was found to be a poor predictor for LIC. SF was significantly lower (P<0.001) in nTx-Thal patients than in other groups, despite similar LIC values. The SF-to-LIC ratio was significantly lower in nTx-Thal compared to Tx-Thal and SCD patients (median of 0.32, 0.87, and 1.2, respectively: P<0.001). Due to underestimation of LIC by ferritin levels, chelation treatment may be delayed or misdirected in patients with thalassemia intermedia.