Cold Agglutinin Disease

Cold agglutinin disease is a rare type of autoimmune hemolytic anemia in which the body's immune system mistakenly attacks and destroys its own red blood cells. When affected people's blood is exposed to cold temperatures (32º to 50º F), certain proteins that normally attack bacteria (IgM antibodies) attach themselves to red blood cells and bind them together into clumps (agglutination). This eventually causes red blood cells to be prematurely destroyed (hemolysis) leading to anemia and other associated signs and symptoms. Cold agglutinin disease can be primary (unknown cause) or secondary, due to an underlying condition such as an infection, another autoimmune disease, or certain cancers. Treatment depends on many factors including the severity of the condition, the signs and symptoms present in each person, and the underlying cause.