LAUSR

iron overload. We used a reference group of SCD and β-thalassemia patients. Percentage iron overload in our transfused SCD patients was comparable to published data. However, we did also find 2 patients with SCD (1 Hemoglobin SS [HbSS], 1 Hemoglobin SE [HbSE]) who were never transfused but did have LIC > 3 mg/g. This is interesting, as in general it is perceived that patients with SCD do not suffer from nontransfusion related iron overload. We included only patients who had MRI LIC data available. This creates a selection bias, but since we aimed to study the occurrence of iron overload and not its prevalence, the data can be considered representative. We did not correct for chelation therapy. Therefore, it is possible that the real prevalence of iron overload in HHA is even higher than described here, as effective chelation therapy reduces or even normalizes LIC levels. In this study, in order to completely eliminate the confounding effect of transfusions, we added a very strictly defined group of never-transfused patients. Even in this group there were patients with moderate to severe iron overload. This indicates that non-transfusion related iron overload, due to inappropriately increased dietary uptake, does occur in rare HHA. In conclusion, this study demonstrates that iron overload is present in all forms of rare HHA, even in patients who were never transfused. The traditionally used cut-off of plasma ferritin >1000 ng/mL and even >800 ng/mL appears to be a poor predictor for liver iron overload. We suggest that all patients with rare HHA, possibly except those with ferritin levels below 500 ng/mL ánd TSAT below 45%, should be evaluated for iron overload with MRI.