What Causes Autoimmune Hemolytic Anemia?
Autoimmune hemolytic anemia (AIHA) is a condition characterized by the premature destruction of red blood cells due to an abnormal immune response. Here are the primary causes:
1. Autoantibodies
The primary cause of AIHA is the production of autoantibodies that mistakenly target red blood cells. These autoantibodies can be of two types:
- Warm Autoantibodies: Typically active at body temperature and most commonly associated with AIHA.
- Cold Autoantibodies: Active at lower temperatures, often leading to hemolysis in colder environments.
2. Underlying Conditions
Several diseases can trigger AIHA, including:
- Autoimmune Disorders: Conditions like lupus erythematosus or rheumatoid arthritis often result in the production of autoantibodies.
- Infections: Certain viral infections (e.g., Epstein-Barr virus) and bacterial infections can stimulate the immune response.
- Cancers: Lymphoproliferative disorders, such as lymphomas or leukemia, can also lead to AIHA.
3. Idiopathic Cases
In some instances, the exact cause of AIHA remains unknown, classified as idiopathic autoimmune hemolytic anemia. This form can arise spontaneously without an identifiable trigger.
4. Genetic Factors
Certain individuals may have genetic predispositions that increase their susceptibility to autoimmune diseases, including AIHA.
Understanding these causes is essential for effective diagnosis and treatment of autoimmune hemolytic anemia.