The animated videos in NORD’s Rare Disease Video Library provide brief introductions to rare disease topics for patients, caregivers, students, professionals and the public. NORD collaborates with medical experts, patient organizations, videographers and Osmosis to develop the videos, which are made possible by individual donations, educational grants and corporate sponsorships. NORD is solely responsible for the content.
Cold agglutinin disease (CAD) is a rare autoimmune disorder characterized by the premature destruction of red blood cells (hemolysis). Autoimmune diseases occur when one’s own immune system attacks healthy tissue. More specifically, CAD is a subtype of autoimmune hemolytic anemia. In this type of disorder, red blood cells are “tagged” by antibodies and are then destroyed by other types of immune cells. The disease is termed “cold” because the antibodies are active and cause hemolysis at cold temperatures, usually 3 to 4oC (37 to 39oF), which is not necessarily the case in other types of autoimmune hemolytic anemia. CAD affects about one person per million every year, and mostly develops between the ages of 40 and 80 years. Normally, the red blood cells have a life span of approximately 120 days before they are destroyed by the spleen. In individuals with CAD, 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, a pale skin color (pallor), dizziness, palpitations, and shortness of breath (dyspnea). Hemolysis leads to an increased release from 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. Other symptoms that can be triggered by exposure to cold include sweating and coldness of the fingers and/or toes (digits) and painful bluish or reddish discoloration of the skin of the digits, ankles, and wrists (acrocyanosis or Raynaud sign). Treatment of CAD includes avoidance of cold temperatures, treating anemia and hemolysis (if needed) and medications that modulate the immune system to decrease the production of antibodies against red blood cells. If applicable, the underlying disease that caused CAD should be treated.