Autoimmune Hemolytic Anemia

Autoimmune hemolytic anemia (AIHA) is an acquired autoimmune disorder characterized by accelerated erythrocyte destruction due to autoantibodies against red blood cell surface antigens. The most important laboratory test for diagnosing AIHA is the direct antiglobulin test (DAT), which detects antibodies or complement proteins on the surface of red blood cells. A positive DAT is strong evidence of AIHA in the setting of hemolytic anemia, but up to 10% of patients with AIHA may have a negative DAT. Once AIHA is diagnosed, it is essential to identify any underlying conditions that may be present in half of the patients, including other immune disorders, lymphoproliferative neoplasms, and infections. Close collaboration between clinicians and laboratory professionals is essential to establish an accurate diagnosis of AIHA.