Faulty blood typing misled by auto anti-D in AIHA.

Pre-transfusion testing is a vital link to enhance patients' safety but may be influenced by heterotypic blood transfusion and disease. Previous history of blood transfusion most of time help us determine the blood type. On the other hand, it can also mislead technicians to a wrong conclusion. Anti-D, which is clinically important in hemolytic transfusion reaction, is either alloimmunized by transfusion, pregnancy or induced in certain diseases. Here, we reported a rare case with false blood identification interfered by heterotypic blood transfusion and auto anti-D in autoimmune hemolytic anemia (AIHA).