Autoimmune Hemolytic Anemia
Autoimmune hemolytic anemia is a group of
disorders characterized by a malfunction of the immune system that
produces autoantibodies, which attack red blood cells as if they
were substances foreign to the body.
Autoimmune hemolytic anemia is an uncommon group of
disorders that can occur at any age. These disorders affect women
more often than men. About half of the time, the cause of autoimmune
hemolytic anemia cannot be determined (idiopathic autoimmune
hemolytic anemia). Autoimmune hemolytic anemia can also be caused by
or occur with another disease, such as systemic lupus erythematosus,
and it can follows the use of certain drugs, such as
Destruction of red blood cells by autoantibodies may
occur suddenly, or it may develop gradually. In some people, the
destruction may stop after a period of time; whereas in other
people, it persists and becomes chronic. There are two main types of
autoimmune hemolytic anemia: warm antibody hemolytic anemia and cold
antibody hemolytic anemia. In the warm antibody type, the
autoantibodies attach to and destroy red blood cells at temperatures
equal to or in excess of normal body temperature. In the cold
antibody type, the autoantibodies become most active and attack red
blood cells only at temperatures well below normal body temperature.
Some people with autoimmune hemolytic anemia may have no symptoms, especially when the destruction of red blood cells is mild and develops gradually. Others have symptoms similar to those that occur with other types of anemia, especially when the destruction is more severe or rapid. When severe or rapid destruction of red blood cells occurs, mild jaundice may also develop. When destruction persists for a few months or longer, the spleen may enlarge, resulting in a sense of abdominal fullness and, occasionally, discomfort.
When the cause of autoimmune hemolytic anemia is another disease, symptoms of the underlying disease, such as swollen and tender lymph nodes and fever, may dominate.