Anti-c Alloimmunization Associated with Acute Hemolytic Transfusion Reaction in a Chronically Transfused β-Thalassemia Patient: A Case Report

Abstract

Red blood cell (RBC) alloimmunization is a significant complication in chronically transfused patients with transfusion-dependent β-thalassemia. Antibodies directed against Rh antigens, particularly anti-c, are clinically important because they may lead to acute or delayed hemolytic transfusion reactions and complicate future transfusion support. We report the case of a 28-year-old woman with transfusion-dependent β-thalassemia who presented with severe anemia and acute febrile illness. Shortly after transfusion, she developed clinical features suggestive of acute hemolytic transfusion reaction accompanied by septic shock and coagulopathy. Immunohematological investigation revealed the presence of clinically significant anti-c alloantibody. Antibody screening and identification were performed using solid-phase red cell adherence technology on the NeoIris platform. Extended Rh phenotyping demonstrated compatibility with c-antigen–negative donor units (CCee) and incompatibility with a c-antigen–positive unit (CcEe), confirming anti-c specificity. The patient was subsequently transfused with two compatible c-negative packed red blood cell units, resulting in hematologic and clinical improvement without further transfusionrelated complications. This case highlights the importance of routine antibody screening, extended Rh phenotyping, and provision of antigen-matched blood in chronically transfused patients to minimize alloimmunization and improve transfusion safety.