Evaluation of the 5 mg/g liver iron concentration threshold and its association with morbidity in patients with β-thalassemia intermedia

Iron overload may still occur in transfusion-independent patients with β-thalassemia intermedia due to increased intestinal iron absorption. In this study, we evaluated the association between iron overload, using a liver iron concentration threshold of therapeutic significance (≥ 5 mg/g), and morbidity in 168 chelation naive patients with β-thalassemia intermedia. We demonstrated that patients with a liver iron concentration ≥ 5 mg/g have a significantly higher prevalence of several serious vascular and endocrine/bone morbidities than do patients with < 5 mg/g, and we established absolute morbidity risk values differentiating both groups. We also demonstrated that the association between iron overload and morbidity in such patients is independent of the effects of advancing age and disease severity. These findings suggest that treating iron burden in β-thalassemia intermedia may be associated with reduction in serious morbidity risk.