en قلب Heart پژوهشي Research <div><strong>Background: </strong>Recurrent blood transfusion is a common treatment in patients with thalassemia. The development of antibodies against red blood cell (RBC) antigens complicates RBC cross-matching, enhances the in vivo destruction of transfused cells, accelerates tissue iron overloading, delays the provision of safe transfusion, and reduces health-related quality of life.<br> <strong>Materials and Methods: </strong>In total, 516 thalassemia patients with a mean age of 18.5 years were included in this cross-sectional study in Mashhad University of Medical Sciences, Razavi Khorasan Province, Iran, in cooperation with the Abu Rayhan Special Medical Center and Hormozgan Blood Transfusion Organization between June 2015 and May 2016. The detection and identification of alloantibodies were done using 3 screen cells and 11 panel cells, respectively. To detect autoantibodies, auto-control was performed using polyspecific Coombs (IgG + C3d) standard method.<br> <strong>Results: </strong>Alloantibodies and autoantibodies were observed in 16 (3.1%) and 21 (4.1%) patients, respectively. Among patients with alloantibodies, 2 patients (12.5%) developed 3 antibodies (Anti-c,E,P1; Anti-c,E,K), 1 patient (6.25%) developed 2 antibodies (Anti-D,C), and 13 patients developed 1 antibody (4 patients Anti-D (25%); 3 Anti-K (18.75%); 2 Anti-E (12.5%); 2 Anti-C (12.5%); 1 Anti-Jka (6.25%); and 1 Anti-Jkb (6.25%)). A statistically significant correlation between patient age (P = 0.031), age of splenectomy (P = 0.006), Rh(D) (P = 0.001), leukoreduction of RBCs (P = 0.043), and type of disease (P = 0.006) with RBC alloimmunization was seen.<br> <strong>Conclusions: </strong>This study emphasized the need for the determination of RBC minor antigens, especially for Rh, Kell, and Kidd blood group systems, before the first transfusion and transfusion of antigen-matched blood. In addition, transfusion of prestorage leukoreduced packed cells is recommended for these patients.<br> &nbsp;</div> Alloimmunization, Autoimmunization, Blood Transfusion, Thalassemia 40 47 http://ijpho.ssu.ac.ir/browse.php?a_code=A-10-519-1&slc_lang=en&sid=1 Farogh Homeirani hemato93@icloud.com No MSc student of Hematology & Blood Banking, Department of Hematology and Blood Bank Mohammad Reza Keramati Keramatimr@mums.ac.ir Yes Cancer molecular pathology research center, Emam Reza hospital Mohammad Hadi Sadeghian No Cancer molecular pathology research center, Emam Reza hospital Zeynab Mozafari No MSc of immunology Azam Moradi Zarmehri No Faculty of Medicine