Warm autoimmune hemolytic anemia (wAIHA) is an autoimmune disorder characterized by the premature destruction of healthy red blood cells (hemolysis). Autoimmune diseases occur when someone’s own immune system attacks healthy tissue. In the case of wAIHA and other types of autoimmune hemolytic anemia, red blood cells are “tagged” by antibodies and are then destroyed by other types of immune cells. wAIHA is the most common type of autoimmune hemolytic anemia; it affects approximately 1 to 3 per 100,000 people every year and can occur at any age. The disease is termed “warm” because the antibodies are active and cause hemolysis at body temperature, which is not necessarily the case in other types of autoimmune hemolytic anemia. Normally, the red blood cells have a life span of approximately 120 days before they are destroyed by the spleen. In individuals with wAIHA, the red blood cells are destroyed prematurely and the rate of production of new cells in the bone marrow can no longer compensate for their loss.
A decreased number of red blood cells (anemia) may cause fatigue, weakness, pale skin color (pallor), dizziness, palpitations and shortness of breath (dyspnea). Hemolysis leads to an increased release from the red blood cells of hemoglobin, a protein responsible for carrying oxygen in the blood. Degradation of hemoglobin into bilirubin can result in yellowing of the skin and whites of the eyes (jaundice). Hemoglobin can also pass in the urine and give it a dark brown color. The treatment of wAIHA is supportive and can also include corticosteroids and/or rituximab. Individuals that do not respond to usual treatment or have more severe disease might require drugs that suppress the immune system (immunosuppressive agents), blood transfusions or surgical removal of the spleen (splenectomy).
