What is autoimmune haemolytic anaemia
What is autoimmune haemolytic anaemia Autoimmune hemolytic anemia (AIHA) is a rare but serious blood disorder characterized by the immune system mistakenly attacking and destroying the body’s own red blood cells. Red blood cells are essential for transporting oxygen from the lungs to tissues throughout the body. When their destruction exceeds production, it results in anemia, leading to symptoms such as fatigue, weakness, pallor, shortness of breath, and rapid heartbeat.
The fundamental cause of AIHA involves an abnormal immune response. Normally, the immune system produces antibodies to fight off infections and foreign invaders. In AIHA, however, the immune system produces autoantibodies—proteins that target the body’s own red blood cells. These autoantibodies bind to the surface of red blood cells, marking them for destruction either in the spleen, liver, or through other immune pathways. This process can be acute or chronic and varies in severity among individuals.
There are two primary types of AIHA based on the temperature at which the autoantibodies optimally bind to red blood cells. Warm AIHA, the more common form, involves autoantibodies that are active at body temperature (around 37°C). Cold AIHA involves autoantibodies that bind to red blood cells at lower temperatures, typically in the extremities. Each type has distinct clinical features and management strategies.
The diagnosis of AIHA involves a combination of blood tests. A complete blood count (CBC) typically shows anemia, with reduced red blood cell count and hemoglobin levels. A direct antiglobulin test (Coombs test) is crucial, as it detects the presence of autoantibodies attached to red blood cells. Additional tests might include blood smear examinations, reticulocyte counts (to assess bone marrow response), and measurements of bilirubin and lactate dehydrogenase (LDH), which can indicate red cell destruction.
Treatment strategies for AIHA are tailored to its severity and type. Corticosteroids, such as prednisone, are usually the first line of therapy, as they suppress the immune response and reduce autoantibody production. If steroids are ineffective, other immunosuppressive agents like rituximab or immunoglobulin therapy may be considered. In severe cases where anemia is life-threatening, blood transfusions may be necessary, though they are used cautiously due to potential complications from autoantibodies. For some patients, splenectomy—the surgical removal of the spleen—can decrease red blood cell destruction, especially in cases of warm AIHA.
Managing AIHA also involves addressing underlying or associated conditions, such as autoimmune diseases, infections, or lymphoproliferative disorders. Regular monitoring is essential to detect relapses or complications, including anemia recurrence or side effects of long-term immunosuppression.
While AIHA can be challenging to treat, many patients achieve remission with appropriate therapy. Early diagnosis and intervention are vital to prevent severe anemia and its complications. Advances in understanding immune regulation continue to improve treatment options, offering hope for better management and outcomes.
