Soluble hemojuvelin in transfused and untransfused thalassaemic subjects

OBJECTIVE: The hemojuvelin-bone morphogenetic protein axis is the principal iron-dependent mechanism of hepcidin regulation. The determination of soluble hemojuvelin (sHJV) levels could allow for a better understanding of the pathophysiological mechanisms of hepcidin regulation in thalassaemia. METHOD: We have assessed sHJV in 45 transfused and 15 untransfused thalassaemic patients in comparison with 15 healthy subjects, evaluating its relationships with some parameters of iron overload, anaemia and erythropoiesis. RESULTS: Untransfused thalassaemic patients had more severe anaemia and erythropoietic activity, while in transfused patients, the transfused RBCs reduced % reticulocytes and sTfR, increased serum indices of iron overload and iron stores in the liver (low MRI T2* values). sHJV levels were higher in patients than in controls and in untransfused in comparison with transfused patients. In the transfused group, we also found that sHJV values are significantly related to serum ferritin, cardiac MRI T2* and growth differentiation factor 15 and are sensitive to hepatitis C virus infection. CONCLUSION: These results suggest that sHJV synthesis seems to be affected by an erythropoietic/hypoxic signal in untransfused patients that have severe anaemia, while in regularly transfused subjects, it is influenced by iron stores.