Evolution of iron burden in acquired aplastic anemia: a cohort study of more than 3-year follow-up.

Acquired aplastic anemia (AA) is the most common condition linked to transfusion dependence. We conducted a cohort study to explore patterns of the dynamic evolution of iron burden, and to identify the risk factors for iron overload (IO) in 550 AA patients. Of the participants, 13 % presented with IO when diagnosed, including 7 % of patients without a history of transfusion and 22 % of those receiving transfusions. Male patients [hazard ratio (HR) = 3.85, 95 % confidence interval (CI) 1.77-8.36], adults (HR = 3.04, 95 % CI 1.21-7.63), and patients with high transfusion burdens (more than eight units; HR = 11.30, 95 % CI 4.45-28.70) experienced a significantly higher risk of IO. Furthermore, we found a sharply increasing risk of IO within the first 2 years, especially in males, patients with large number of lifetime transfusions, and patients not responding to treatment. More interestingly, after transfusion independence, a significant seesaw effect between erythropoiesis and iron burden was not noted until 6 months later, which continued over 3 years. In contrast to female patients, children, and patients with lower transfusion burdens, male subjects, adults, and subjects with high transfusion burdens experienced a pattern of slow decline in iron burden. AA incurred a high risk of progression to IO and showed distinct patterns in the evolution of iron burden. In light of these data, we offer suggestions for decision-making regarding who should undergo iron chelation and when.