The Correlation Between Frequency of Transfusion and Alloimmunization in Transfusion-Dependent Thalassemia Patients Aimmatul Yumna Nihayatul Wafa1, Betty Agustina Tambunan2*and Mia Ratwita Andarsini3 Abstract Thalassemia is a red blood cell disorder caused by impaired synthesis of hemoglobin and is genetically inherited. Based on the need for transfusion, thalassemia is divided into