Autoimmune hemolytic anemias (AIHA) are a group of disorders characterized by the destruction of red blood cells (RBCs) by the body's own immune system. In AIHA, the body produces an antibody that attacks its own RBCs, leading to anemia. One of the main characteristics of AIHA is that the RBCs are often larger than normal, a condition known as macrocytosis.
What Causes Macrocytosis in AIHA?
Macrocytosis in AIHA is caused by the destruction of RBCs at a rate faster than the bone marrow can produce replacements. This results in a decrease in the production of healthy RBCs and an increase in the production of larger, immature RBCs known as macrocytes. Macrocytes are too large to pass through the spleen and are therefore removed from circulation, leading to anemia.
How Is Macrocytosis Diagnosed?
Macrocytosis in AIHA is diagnosed through a peripheral blood smear. A peripheral blood smear is a sample of your blood that is examined under a microscope. During the examination, your doctor will look for larger-than-normal RBCs, which can indicate the presence of macrocytosis. In addition, your doctor may order additional tests, such as a complete blood count (CBC), to confirm the diagnosis.
Treatment of Macrocytosis in AIHA
The treatment of macrocytosis in AIHA depends on the severity of the anemia. Mild cases may be managed with lifestyle changes, such as avoiding drugs and alcohol, eating a balanced diet, and avoiding strenuous activity. For more severe cases, your doctor may prescribe medications, such as corticosteroids, to reduce inflammation and suppress the immune system. In some cases, a blood transfusion may be necessary to replace the destroyed RBCs.
