Evaluation of angiogenesis with vascular endothelial growth factor in patients with thalassemia major.

Background:  Thalassemia major (TM) is an important cause of severe anemia that necessitates regular blood transfusion to prevent the profound weakness and cardiac decompensation caused by the anemia. However, iron overloading is an inevitable consequence of prolonged transfusion therapy. In addition, extramedullary hematopoiesis and hemosiderosis cause spleen, liver and marrow enlargement. In recent years the role of angiogenesis has been investigated in physiological and pathological conditions. However, it is known that angiogenetic factors, especially the vascular endothelial growth factor (VEGF), cause differentiation of the hemangioblast. Methods:  The effect of angiogenesis hasn't been investigated in TM patients yet, and in this study, angiogenesis was researched in 43 thalassemic patients by serum VEGF measurement. Results:  VEGF levels were not affected by hemoglobin levels, ferritin levels, or chelation type (P > 0.05). However, VEGF was positively affected by chelation starting age and negatively affected by yearly transfusion requirement of TM patients (P < 0.05). In addition, VEGF of patients who underwent splenectomy were higher than those who didn't undergo splenectomy (P < 0.05). Conclusion:  Early chelating age will negatively influence the VEGF level, which increases angiogenesis, however, early starting transfusion age and regular blood transfusion will positively influence the VEGF level, which decreases angiogenesis in thalassemic patients.